Recent Publications, Reports, and more from the Prairie Research Institute

This list includes recent external publications (e.g., journal articles) authored by institute staff, recent items published by the Institute's Divisions, recent technical reports, and recent dissertations and theses from students whose graduate advisor was an Institute staff member.   For complete catalogs of in-house publications and staff bibliographies of external publications by Division, please see the Institute Publications page on the Prairie Research Institute Library website.

# Recent Publications, Reports, and more from the Prairie Research Institute

• 9/9/2014
Author:
Webb, Dan, George Czapar

Call Number:
ISWS C-185
• 8/19/2014
Author:
Byard, Gregory J., Ryan Meekma, Brad McVay, Sally McConkey

Call Number:
ISWS CR 2014-03
• 7/11/2014
Author:
Wetherbee, Gregory, Rose Ann Martin

Call Number:
ISWS MP-202
• 5/29/2014
Author:
Bekele, Elias, Laura Keefer, Sangeetha Chandrasekaran

Call Number:
ISWS CR 2014-02
• Publication date: March 2014
Source:Atmospheric Environment, Volume 85

Author(s): Martin R. Risch , Donna M. Kenski , David A. Gay

As many as 51 mercury (Hg) wet-deposition-monitoring sites from 4 networks were operated in 8 USA states and Ontario, Canada in the North American Great Lakes Region from 1996 to 2010. By 2013, 20 of those sites were no longer in operation and approximately half the geographic area of the Region was represented by a single Hg-monitoring site. In response, a Great Lakes Atmospheric Mercury Monitoring (GLAMM) network is needed as a framework for regional collaboration in Hg-deposition monitoring. The purpose of the GLAMM network is to detect changes in regional atmospheric Hg deposition related to changes in Hg emissions. An optimized design for the network was determined to be a minimum of 21 sites in a representative and approximately uniform geographic distribution. A majority of the active and historic Hg-monitoring sites in the Great Lakes Region are part of the National Atmospheric Deposition Program (NADP) Mercury Deposition Network (MDN) in North America and the GLAMM network is planned to be part of the MDN. To determine an optimized network design, active and historic Hg-monitoring sites in the Great Lakes Region were evaluated with a rating system of 21 factors that included characteristics of the monitoring locations and interpretations of Hg data. Monitoring sites were rated according to the number of Hg emissions sources and annual Hg emissions in a geographic polygon centered on each site. Hg-monitoring data from the sites were analyzed for long-term averages in weekly Hg concentrations in precipitation and weekly Hg-wet deposition, and on significant temporal trends in Hg concentrations and Hg deposition. A cluster analysis method was used to group sites with similar variability in their Hg data in order to identify sites that were unique for explaining Hg data variability in the Region. The network design included locations in protected natural areas, urban areas, Great Lakes watersheds, and in proximity to areas with a high density of annual Hg emissions and areas with high average weekly Hg wet deposition. In a statistical analysis, relatively strong, positive correlations in the wet deposition of Hg and sulfate were shown for co-located NADP Hg-monitoring and acid-rain monitoring sites in the Region. This finding indicated that efficiency in regional Hg monitoring can be improved by adding new Hg monitoring to existing NADP acid-rain monitoring sites. Implementation of the GLAMM network design will require Hg-wet-deposition monitoring to be: (a) continued at 12 MDN sites active in 2013 and (b) restarted or added at 9 NADP sites where it is absent in 2013. Ongoing discussions between the states in the Great Lakes Region, the Lake Michigan Air Directors Consortium (a regional planning entity), the NADP, the U.S. Environmental Protection Agency, and the U.S. Geological Survey are needed for coordinating the GLAMM network.

• 10/1/2014
• Publication date: 15 August 2014
Source:Journal of Colloid and Interface Science, Volume 428

Author(s): Tias Paul , Jinyong Liu , Michael L. Machesky , Timothy J. Strathmann

Fluoroquinolone (FQ) antibacterials are aquatic contaminants of emerging concern (CEC), and adsorption to mineral surfaces is expected to play an important role in the fate, transport, and treatment of FQs. This study characterizes and models the adsorption of a zwitterionic FQ, ofloxacin (OFX), to goethite (α-FeOOH) over a wide range of pH (3–11), OFX concentration (20–500μM), and electrolyte compositions (0.001–0.1M NaCl and NaClO4). Comparing OFX adsorption to structural analogues demonstrates that the carboxylate group is essential for binding to goethite. ATR-FTIR measurements indicate that FQs complex to goethite surfaces through carboxylate and carbonyl oxygen atoms, and that ClO4 co-adsorbs with OFX. Adsorption of the zwitterionic OFX increases with increasing ionic strength and is enhanced in NaClO4 relative to NaCl electrolyte, whereas adsorption of a non-zwitterionic analogue is insensitive to ionic strength. A CD-MUSIC (charge distribution-multisite complexation) model, incorporating multiple modes of surface complexation constrained by spectroscopic measurements and the crystallographic distribution of goethite surface sites, yields accurate predictions over wide-ranging solution conditions. According to the model, OFX adsorbs predominantly by inner-sphere complexation on terminal surfaces of the rod-shaped goethite crystals in NaCl electrolyte, and OFX-ClO4 ion pairing in NaClO4 induces formation of additional inner- and outer-sphere surface complexes on multiple crystal faces of goethite.

### Graphical abstract

• Publication date: September 2014
Source:Journal of Great Lakes Research, Volume 40, Issue 3

Author(s): Bin Huo , Charles P. Madenjian , Cong X. Xie , Yingming Zhao , Timothy P. O’Brien , Sergiusz J. Czesny

The round goby (Neogobius melanostomus) is a prevalent invasive species throughout Lake Michigan, as well as other Laurentian Great Lakes, yet little information is available on spatial variation in round goby growth within one body of water. Age and growth of round goby at three areas of Lake Michigan were studied by otolith analysis from a sample of 659 specimens collected from 2008 to 2012. Total length (TL) ranged from 48 to 131mm for Sturgeon Bay, from 50 to 125mm for Waukegan, and from 54 to 129mm for Sleeping Bear Dunes. Ages ranged from 2 to 7years for Sturgeon Bay, from 2 to 5years for Waukegan, and from 2 to 6years for Sleeping Bear Dunes. Area-specific and sex-specific body–otolith relationships were used to back-calculate estimates of total length at age, which were fitted to von Bertalanffy models to estimate growth rates. For both sexes, round gobies at Sleeping Bear Dunes and Waukegan grew significantly faster than those at Sturgeon Bay. However, round goby growth did not significantly differ between Sleeping Bear Dunes and Waukegan for either sex. At all three areas of Lake Michigan, males grew significantly faster than females. Based on catch curve analysis, estimates of annual mortality rates ranged from 0.79 to 0.84. These relatively high mortality rates suggested that round gobies may be under predatory control in Lake Michigan.

• Publication date: August 2014
Source:Current Opinion in Insect Science, Volume 2

Author(s): Gaylord A Desurmont , Ian S Pearse

Introductions of both plants and herbivorous insects have had tremendous impacts on the world's ecosystems. Novel herbivorous insect–plant interactions are important consequences of introductions of either plants or herbivorous insects. We contrast novel herbivorous insect–plant interactions that arise due to plant versus insect introductions with the aim of understanding whether the causes and consequences of the interaction depend on which party is non-native. The biotic context of the herbivore–plant interaction, in terms of mutualists, predators, and competitors can limit the prevalence of that interaction and varies between native and introduced ranges. Introduced plants can have a large, direct impact on their environment, whereas the impact of introduced herbivorous insects is often mediated through the plants that they consume.

• Publication date: February 2015
Source:Quaternary Geochronology, Volume 25

Author(s): David A. Grimley , Eric A. Oches

Amino acid racemization (AAR) values measured in gastropod shells are demonstrated to be an important aid for correlations and chronology of fossiliferous loessal, lacustrine, and alluvial Pleistocene units in Illinois, central USA. Aspartic acid (Asx) and Glutamic acid (Glx) D/L values were analyzed on a total of 167 Succinea, Hendersonia, and Pomatiopsis shells from 9 geologic units, with clear stratigraphic relationships, at a total of 18 localities in central and southern Illinois. AAR data from Hendersonia and Succinea are less variable and more normally distributed than Pomatiopsis data, but the latter are locally useful for units lacking preferred genera. Based on analysis of variance tests, Asx- and Glx-D/L data can confidently distinguish among Wisconsin Episode (MIS 2–3), Illinois Episode (MIS 6), late pre-Illinois Episode (MIS 8–14), and early pre-Illinois Episode (MIS 20) deposits. Last glacial Peoria Silt (MIS 2) and Roxana Silt (MIS 3), have mean Asx-D/L values of 0.34–0.37 and 0.42–0.43, respectively, considering all genera. The Illinois Episode Petersburg Silt (∼150 ka) has Asx-D/L ($x ¯$: 0.50–0.56) and Glx- D/L ($x ¯$: 0.17–0.22) ratios that are statistically distinctive from other units. Three late pre-Illinois Episode units (Harkness Silt Member, Belgium Member, and Banner silt units) have similar Asx D/L values ($x ¯$: 0.63–0.71) and, along with stratigraphic context, confirm extensive middle Pleistocene glaciations in the region. Using parabolic kinetic age models, depositional ages of ∼550–250 ka (MIS 14–8) are implied for these units, with a favored correlation with MIS 12 (∼450 ka), a time of especially high global ice volume. The Canteen member, a preglacial alluvium–colluvium below the Harkness Silt, is statistically indistinguishable from other pre-Illinois Episode units with AAR data, but was likely deposited during ∼660–480 ka (MIS 16 or 14), based on parabolic age estimates. The paleomagnetically reversed County Line silt (∼780–830 ka: MIS 20), with the highest mean AAR values, is the oldest known gastropod-bearing Pleistocene unit in Illinois.

• Publication date: 16 July 2014
Source:Journal of Hydrology, Volume 515

Author(s): Daeryong Park , Momcilo Markus

The Pecatonica River and several other streams in the Wisconsin Driftless area show a decreasing trend in annual peak flows. Previous studies of the Pecatonica River detected a significant decreasing historical trend in late winter snowmelt-driven floods, while the rainfall-driven spring and summer flood peaks exhibited no significant trend during the period of record. Unlike several previous studies which attribute the decline in flood peaks mainly to changes in land management, we hypothesize that climate change had a significant contribution to the overall decrease in flood peaks. In particular, we hypothesize that the increase in winter temperatures caused the decrease in snow depth, which in turn resulted in a decreasing trend in flood peaks. In an attempt to validate this hypothesis, we used long-term daily precipitation, temperature, and river flow data observed in the watershed as inputs to the Variable Infiltration Capacity (VIC) model to generate other non-monitored climatic variables. Trends in these climatic variables were then related to the trend in flood peaks in the Pecatonica River. Due to the complexity of the hydrologic system and numerous data and modeling-related uncertainties, the above hypothesis cannot be validated with certainty. Nonetheless, the results in two different modes (event and continuous simulation) provide support to the speculation that the decreasing trend in flood peaks was a result of decreasing snow depth. The model runs resulted in a decrease in snow depths for the period of record (1915–2009), increase in sublimation and evaporation, no change in base flow, and mixed results in infiltration. These analyses also suggest that VIC can be used in other similar regions in snowmelt-driven flood peak studies. It should be recognized, however, that the success of these applications can be severely constrained by various uncertainties, including but not limited to, the poor quality or absence of snow depth data.

• Marshall, Charla; Kaestle, Frederika A. writer Marshall, Charla; Kaestle, Frederika A. by Marshall, Charla; Kaestle, Frederika A. published by Marshall, Charla; Kaestle, Frederika A.
Midcontinental Journal of Archaeology; 10/01/2013
(AN 92620217)
America: History & Life
• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• Publication date: September 2014
Source:Cretaceous Research, Volume 51

Author(s): Yosmel Sanchez-Hernandez , Florentin J.-M.R. Maurrasse , Mihaela C. Melinte-Dobrinescu , Ding He , Shane K. Butler

The Organyà Basin, south–central Spanish Pyrenees, developed as a marginal depocenter during a rapid extensional phase of anticlockwise rotation of the Iberian plate. As a result of increased subsidence, an important change in sedimentation occurred from the late Barremian to the Aptian leading to unusually high sediment accumulation rates. Approximately 1000 m of hemipelagic marls and limestones accumulated during this time interval. Here we studied the basal 85 m of the hemipelagic facies of the El Pui section, Organyà Basin, that are characterized by alternating 15 cm – ∼3 m thick beds of limestone and marls. Geochemical analyses indicate high total inorganic carbon (TIC) values (average 70%) suggesting enhanced CaCO3 production and deposition. SEM analyses of the samples indicate high abundance of calcareous nannofossils, which together with the absence of shallow water taxa characteristic of the Urgonian Carbonate platform of Organyà, and the lack of sedimentary facies attributable to carbonate platform components point to nannofossils as the main source for the elevated TIC. Organic-rich levels (total organic carbon (TOC) up to 1.74%) concurrent with positive excursions up to 2‰ in δ13Corg, imply enhanced preservation of organic matter (OM) in the basin. In addition, pronounced peaks of δ13Corg higher than the global average suggest superimposed local factors related to intensified 12C removal due to primary productivity. Biomarker analyses and the δ13Corg profile suggest an autochthonous origin of the OM from phytoplankton and possible additional contributions from microbial communities. X-ray diffraction (XRD) results attest for sustained terrestrial fluxes as the source of nutrients to the basin because of a 30% average non-carbonate bulk mineral content in the sediment. The non-carbonate fraction is dominated by quartz (average, 14%) whereas the clay mineral assemblages are characterized by high illite content (&gt;73 relative%) with minor concentrations of kaolinite (&lt;5%), illite /smectite mixed layers (&lt;17%) and chlorite (&lt;15%), consistent with a provenance from the Paleozoic metamorphic terranes adjacent to the Organyà Basin. The integrated results suggest a high sediment accumulation rate (5 cm/ky–7.5 cm/ky) and enhanced carbon burial during the latest Barremian–earliest Aptian in the hemipelagic setting of the El Pui section.

• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• Kozuch, Laura writer Kozuch, Laura by Kozuch, Laura published by Kozuch, Laura
Southeastern Archaeology; 07/01/2013
(AN 89690048)
America: History & Life
• Mazrim, Robert F.; Walthall, John A. writer Mazrim, Robert F.; Walthall, John A. by Mazrim, Robert F.; Walthall, John A. published by Mazrim, Robert F.; Walthall, John A.
Midcontinental Journal of Archaeology; 10/01/2012
(AN 85351845)
America: History & Life
• 10/1/2014
• Publication date: 2015
Source:Thorp and Covich's Freshwater Invertebrates

Author(s): Kevin S. Cummings , Daniel L. Graf

Two native groups represent the freshwater bivalves of North America: the freshwater mussels (Unionoidea) and the pill, fingernail, and pea clams (Sphaeriidae). There are also two widely publicized invasive genera, Corbicula and Dreissena. These mollusks have interesting and important ecological interactions with their environments, not the least of which is their relationship to humans. The bias of this chapter is toward the freshwater mussels. They are the numerically dominant group, with 10 times more species, and considerably more data are available on them. This chapter covers general biology, including internal and external anatomy, physiology, and reproduction. General ecology is discussed, including life-cycles, age and growth, and biotic interactions. The role of freshwater biovalves as biomonitors is reviewed.

• Publication date: 2015
Source:Thorp and Covich's Freshwater Invertebrates

Author(s): R. Edward DeWalt , Boris C. Kondratieff , John B. Sandberg

Plecoptera, or stoneflies, are an ancient insect order. The order name refers to the ability to fold their wings horizontally. Sixteen extant families and nearly 3,500 valid species are currently known. The nymphs of the vast majority of species are aquatic and most feed in two general categories, as shredders of leaves and as predators of other invertebrates. Adults are terrestrial, inhabiting vegetation near the stream or lake from which they emerged. In this chapter we present the morphology of stoneflies and cover aspects of their ecology and behavior. We also discuss sampling, rearing, and preservation of stonefly specimens. The conservation status of stoneflies is also discussed.

• Publication date: 2014
Source:Insect Resistance Management

Author(s): Joseph L. Spencer , Sarah A. Hughson , Eli Levine

Insect Resistance to Crop Rotation Two species of Diabrotica have evolved resistance to crop rotation that involves planting the same primary crop every second year in the same location. Diabrotica barberi has adapted by extending egg diapause for more than one winter. Diabrotica virgifera virgifera has lost its fidelity for corn, Zea mays, during the oviposition period; eggs are laid in most fields of vegetation in the crop landscape. Both adaptations permit eggs to hatch in cornfields. D. v. virgifera has also evolved resistance to most other IPM tactics over the past 60 years, including one type of insecticidal corn. This chapter explores the diverse approaches to IPM and the role of insect behavior in resistance management.

• Publication date: 6 September 2014
Source:Chemical Engineering Science, Volume 116

Author(s): Xinhuai Ye , Yongqi Lu

The enzyme carbonic anhydrase (CA) has potential as an efficient biocatalyst to promote the absorption of CO2 into potassium carbonate–bicarbonate (K2CO3–KHCO3) solutions for CO2 capture from the flue gas of coal-fired power plants. Knowing the kinetics of the promoted absorption and the catalytic activity and stability of CA under typical operating conditions is essential for process design and techno-economic analysis. In this study, we investigated two specifically engineered CA enzymes and experimentally determined the first-order rate constant of CA (k CA) for catalyzing CO2 hydration into K2CO3–KHCO3 solutions by measuring the rate of CO2 absorption into the solutions in a stirred cell reactor and using the classic Danckwerts theory for data interpretation. The k CA values obtained were $4.02 L mg − 1 s − 1 ( 1.21 × 10 8 M − 1 s − 1$) at 25°C, $4.25 L mg − 1 s − 1$ $( 1.28 × 10 8 M − 1 s − 1$) at 40°C, and $4.07 L mg − 1 s − 1$ $( 1.22 × 10 8 M − 1 s − 1$) at 50°C. These values are applicable in 20wt% K2CO3–KHCO3 solutions with CO2 loadings ranging from 10 to 40% carbonate-to-bicarbonate (CTB) conversion. The k CA value did not substantially depend on the reaction temperatures at 25–50°C, the composition of the 20wt% K2CO3–KHCO3 solutions with 10–40% CTB conversion, or the pH condition (10.1 to 11.0 pH). The rate of CO2 absorption was promoted by two to six times in the presence of $300 mg L − 1$ of CA in 20wt% K2CO3–KHCO3 solutions at 40–60°C. The long-term thermal stability of CA was investigated at 40, 50, and 60°C in 20wt% K2CO3–KHCO3 solutions with 20 and 40% CTB conversion. The activity loss of CA, as indicated by a decrease in the enhancement factor (E CA) over time, was approximately 20% of its initial activity after 6 months at 40°C, was 50% after 2 months and 80% after 4 months at 50°C, and was 60% after 1 month and 80% after 2 months at 60°C. The CA showed comparable thermal stability in solutions with 20 and 40% CTB conversion, indicating that the CO2 loading of the solution was not an important factor in the thermal stability of the enzyme. The resistance of CA to flue gas impurities that may be transformed in the solvent, which are present in the form of $SO 4 2 −$, $NO 3 −$, and Cl anions was examined at 50°C in the 20wt% solution with 20% CTB conversion in the presence of 0.4M K2SO4, 0.3M KCl, and 0.05M KNO3, either alone or in combination. The CA did not show any further appreciable loss of activity or long-term stability in the presence of the simulated impurities at the concentrations investigated. The results of this study provide valuable information and practical guidance for the potential application of CA as a biocatalyst to promote the absorption of CO2 into K2CO3–KHCO3 solutions for CO2 capture.

• Publication date: June 2014
Source:Journal of Applied Geophysics, Volume 105

Author(s): Ahmed Ismail , F. Brett Denny , Mohamed Metwaly

We use the seismic shear-wave reflection and multichannel analysis of surface wave (MASW) methods to examine if the MASW profiling can be an alternative for the shear-wave reflection method for near-surface characterization at specific subsurface settings. The shear wave reflection method does not work well in noisy areas, takes longer time for data acquisition and requires excessive post acquisition processing compared to the MASW method. Two surveys were conducted using land streamer technology along two lines totaling 3.7km in southern Illinois. The reflection data were used to generate seismic reflection profiles. The stacking velocities along the reflection profiles were converted into interval velocities and mapped as 2D velocity images. The MASW data were used to generate continuous 2D shear-wave velocity (Vs ) profiles. The MASW and the stacking-derived interval velocity images provided a smeared image of the overlying sedimentary layers and did not image small-scale features, such as igneous intrusions and near-surface faults. However, the MASW 2D Vs profiles and the reflection profiles compared well in mapping the bedrock surface and the thickness of the overlying unconsolidated sediment. The results confirmed that the MASW method can be an alternative to the reflection method when the survey target and near-surface conditions allow.

• Mazrim, Robert writer Mazrim, Robert by Mazrim, Robert published by Mazrim, Robert
International Journal of Historical Archaeology; 12/01/2013
(AN 90632189)
America: History & Life
• Publication date: February 2014
Source:International Journal of Greenhouse Gas Control, Volume 21

Author(s): Scott M. Frailey

• 10/1/2014
• Publication date: March 2014
Source:Pesticide Biochemistry and Physiology, Volume 110

Author(s): Chia-Ching Chu , Weilin Sun , Joseph L. Spencer , Barry R. Pittendrigh , Manfredo J. Seufferheld

RNA interference (RNAi) mediated crop protection against insect pests is a technology that is greatly anticipated by the academic and industrial pest control communities. Prior to commercialization, factors influencing the potential for evolution of insect resistance to RNAi should be evaluated. While mutations in genes encoding the RNAi machinery or the sequences targeted for interference may serve as a prominent mechanism of resistance evolution, differential effects of RNAi on target pests may also facilitate such evolution. However, to date, little is known about how variation of field insect populations could influence the effectiveness of RNAi treatments. To approach this question, we evaluated the effects of RNAi treatments on adults of three western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte) populations exhibiting different levels of gut cysteine protease activity, tolerance of soybean herbivory, and immune gene expression; two populations were collected from crop rotation-resistant (RR) problem areas and one from a location where RR was not observed (wild type; WT). Our results demonstrated that RNAi targeting DvRS5 (a highly expressed cysteine protease gene) reduced gut cysteine protease activity in all three WCR populations. However, the proportion of the cysteine protease activity that was inhibited varied across populations. When WCR adults were treated with double-stranded RNA of an immune gene att1, different changes in survival among WT and RR populations on soybean diets occurred. Notably, for both genes, the sequences targeted for RNAi were the same across all populations examined. These findings indicate that the effectiveness of RNAi treatments could vary among field populations depending on their physiological and genetic backgrounds and that the consistency of an RNAi trait’s effectiveness on phenotypically different populations should be considered or tested prior to wide deployment. Also, genes that are potentially subjected to differential selection in the field should be avoided for RNAi-based pest control.

### Graphical abstract

• Publication date: 15 March 2014
Source:Geomorphology, Volume 209

Author(s): Andrew J. Stumpf , Travis Ferbey , Alain Plouffe , John J. Clague , Brent C. Ward , Roger C. Paulen , Andrew B.G. Bush

McClenagan (2013) presents a model to explain streamlined erosional residuals or drumlins on uplands and lowlands in the plateau region of central British Columbia, Canada. In this discussion paper, we note that McClenagan (2013) has not adequately discussed previous relevant work in the region, and we argue that additional analyses and evidence are required to substantiate this new model. The hypothesis offered for the origin of the plateau landscape, specifically catastrophic glaciofluvial activity, differs significantly from a model based on glacial erosion and deformation that has been developed from field-based research over the past six decades. We discuss four critical points relating to the proposed model: (1) the current geological model for the plateau region of central British Columbia; (2) theory of glacial dispersal; (3) existing hypotheses for the formation of drumlins and other glacial landforms; and (4) theoretical glacial erosion modeling. We further suggest that the model cannot be substantiated without sedimentological or morphological field evidence for water bodies argued to be the source of the proposed megaflood or megafloods.

• Publication date: 15 August 2014
Source:Chemical Engineering Journal, Volume 250

Author(s): Ling Zhao , Wei Zheng , Xinde Cao

This study investigated the distribution and evolution of organic phases during biochar formation from twelve waste biomass and at the highest heating temperatures between 200°C and 650°C. Relation of the organic phase transformation to the carbon loss and pore structure was also analyzed. The organic phases in both feedstock biomass and the derived biochar were sequentially separated into four fractions: neutral detergent soluble fraction, hemicellulose, cellulose, and lignin. Plant-based residues mainly contained cellulose (25.8–64.6%), while municipal solid wastes had a large fraction of neutral detergent soluble fraction (22.9–65.0%). Transformation of cellulose into detergent soluble fraction and hemicellulose initially happened at the charring temperature between 100°C and 200°C, and the complete transformation was observed at the higher temperatures from 200°C to 350°C. The high lignin amount in biochar may be partly formed from the aromatization of cellulose fraction in addition to the contribution from the existing lignin in feedstock. All biochars had small total pore volumes ranging from 0.009cm3 g−1 to 0.278cm3 g−1 and were a type of mesoporous material with the pore sizes between 2nm and 30nm. The decrease of detergent soluble fraction, hemicellulose, and cellulose fractions had little effect on pore formation, but it was positively related to the C loss during pyrolysis. Pore volume and surface area seemed to have a positive relationship with lignin percentage and insoluble minerals in feedstock. This study provided insight into the mechanism of biochar formation related to the C loss and pore structure evolution. It will help produce the designated biochar with different environmental functions.

• Publication date: February 2014
Source:Acta Tropica, Volume 130

Author(s): Jeffrey J. Bara , Ephantus J. Muturi

Mixed viral infections are ubiquitous in natural populations and may have significant but unpredictable biological and epidemiological consequences. These infections may be acquired simultaneously (coinfection) or result from two single infections at different time intervals (superinfection). This study investigated the effect of mixed infections of two mosquito-borne viruses, Sindbis (SINV) and La Crosse (LACV), on the replication of each virus in vertebrate baby hamster kidney (BHK) and invertebrate Aedes albopictus (C6/36) cell lines. SINV and LACV were inoculated onto confluent monolayers of each cell type either singly, simultaneously, or with a 2-h delay between single inoculations and titers for each virus were quantified by qRT-PCR. The titers for both viruses were significantly higher in BHK compared to C6/36 cells. Mixed infections suppressed replication of both viruses in BHK cells except for one superinfection treatment where inoculation of SINV ahead of LACV did not result in a reduction in SINV titer relative to single infection treatment. In C6/36 cells mixed infections had no effect on LACV replication, while coinfection enhanced SINV replication. These results demonstrate the potential for mixed viral infections to modify arbovirus transmission and pathogenesis.

### Graphical abstract

• Publication date: December 2013
Source:Bioresource Technology, Volume 149

Author(s): Mai Pham , Lance Schideman , Brajendra K. Sharma , Yuanhui Zhang , Wan-Ting Chen

This study investigated the effects of hydrothermal liquefaction (HTL) on the fate of bioactive compounds (BACs) often present with wet biosolids from wastewater, manure, or algae. Tracking radiolabeled 14C for two BACs showed that 60–79% of the carbon was transferred to the HTL raw oil product, and most of the rest was found in the aqueous product. In the presence of both swine manure and Spirulina biomass feedstocks, HTL provided essentially complete removal of three BACs when operated at 300°C for ⩾30min. Experiments with both natural transformation and high-efficiency transformation showed that HTL provided complete deactivation of antibiotic resistant genes for all tested HTL conditions (250–300°C, 15–60min reaction time). Thus, incorporating HTL into wastewater treatment systems can simultaneously produce valuable bio-crude oil, provide effective removal of BACs and disrupt the natural pathways for antibiotic resistant gene transfer from manure and wastewater biosolids to the environment.

• Publication date: June 2014
Source:Chemosphere, Volume 104

Author(s): Jeffrey M. Levengood , David J. Soucek , Gregory G. Sass , Amy Dickinson , John M. Epifanio

Efforts to control invasive bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix) may include harvest for human consumption. We measured concentrations of arsenic (As), mercury (Hg), and selenium (Se) in fillets from silver and bighead carp collected from the lower Illinois River, Illinois, USA, to determine whether concentrations were of health concern and differed by species, size, and location. Concentrations of total As were below detection limits in most bighead (92%) and silver (77%) carp fillets, whereas inorganic As was below detection limits in all samples. Mean Hg concentrations were greater in bighead (0.068mgkg−1) than in silver carp (0.035mgkg−1), and were smallest in carp from the confluence of the Illinois and Mississippi rivers. Mercury concentrations in fillets were positively correlated with body mass in both species. Concentrations of Hg were below the US Food and Drug Administration’s (USFDA) action level (1ppm as methyl-Hg); however, concentrations in some bighead (70%) and silver (12%) carp fell within the range that would invoke a recommendation to limit meals in sensitive cohorts. Mean Se concentrations were greater in silver (0.332mgkg−1) than in bighead (0.281mgkg−1) carp fillets, and were below the 1.5mgkg−1 limit for an unrestricted number of meals/month. The mean molar ratio of Se:Hg in fillets was lower in bighead (14.0) than in silver (29.1) carp and was negatively correlated with mass in both species Concentrations of Hg in bighead and silver carp fillets should be considered when assessing the risks associated with the use of these species as a protein source.

• 10/1/2014
• Fishel, Richard L. writer Fishel, Richard L. by Fishel, Richard L. published by Fishel, Richard L.
Midcontinental Journal of Archaeology; 10/01/2012
(AN 85351847)
America: History & Life
• Publication date: November 2014
Source:Chemosphere, Volume 114

Author(s): Yonghong Zou , Erik R. Christensen , Wei Zheng , Hua Wei , An Li

A stochastic process was developed to simulate the stepwise debromination pathways for polybrominated diphenyl ethers (PBDEs). The stochastic process uses an analogue Markov Chain Monte Carlo (AMCMC) algorithm to generate PBDE debromination profiles. The acceptance or rejection of the randomly drawn stepwise debromination reactions was determined by a maximum likelihood function. The experimental observations at certain time points were used as target profiles; therefore, the stochastic processes are capable of presenting the effects of reaction conditions on the selection of debromination pathways. The application of the model is illustrated by adopting the experimental results of decabromodiphenyl ether (BDE209) in hexane exposed to sunlight. Inferences that were not obvious from experimental data were suggested by model simulations. For example, BDE206 has much higher accumulation at the first 30min of sunlight exposure. By contrast, model simulation suggests that, BDE206 and BDE207 had comparable yields from BDE209. The reason for the higher BDE206 level is that BDE207 has the highest depletion in producing octa products. Compared to a previous version of the stochastic model based on stochastic reaction sequences (SRS), the AMCMC approach was determined to be more efficient and robust. Due to the feature of only requiring experimental observations as input, the AMCMC model is expected to be applicable to a wide range of PBDE debromination processes, e.g. microbial, photolytic, or joint effects in natural environments.

• Marshall, Joel Michael; Krus, Anthony Michal writer Marshall, Joel Michael; Krus, Anthony Michal by Marshall, Joel Michael; Krus, Anthony Michal published by Marshall, Joel Michael; Krus, Anthony Michal
Midcontinental Journal of Archaeology; 10/01/2013
(AN 92620212)
America: History & Life
• 10/1/2014
• Publication date: 25 January 2014
Source:Fluid Phase Equilibria, Volume 362

Author(s): Yudan Zhu , Luzheng Zhang , Xiaohua Lu , Linghong Lu , Ximing Wu

The anomalous flow behavior of nanoconfined water is attracting considerable attention. This study aimed to investigate the effect of pore wall interfacial properties on the flow behavior of water confined in a slit pore. Non-equilibrium molecular dynamics simulations were performed on water molecules confined in slit pores. By moving the two pore walls to opposite directions, the confined water molecules were made in a directed flowing. The flow resistance of the water molecules was then analyzed at the nanoscale. Two Si(111) surfaces were used to construct the slit pore model. The interaction strength, ɛ Si-w, between the pore wall atom and water's oxygen atom was adjusted to represent different pore wall interfacial properties. A higher ɛ Si-w indicates a more hydrophilic pore wall interface. Simulation results show that for the studied cases, more hydrophilic pore walls leads to larger flow resistance of the confined water. At the molecular level, the friction between the pore wall and water molecules increases with increased hydrophilicity of pore walls and further hampers the flow of the confined water in the slit pore. Moreover, simulation results demonstrate that water molecules confined in the slits are layered. The increase in the hydrophilicity increases hydrogen bonds between water layers, thereby enhancing flow resistance arising from the water molecules themselves.

• Publication date: April 2014
Source:Environmental Science &amp; Policy, Volume 38

Author(s): Tamara F. Blett , Jason A. Lynch , Linda H. Pardo , Cindy Huber , Richard Haeuber , Richard Pouyat

• Publication date: 1 December 2013
Source:Geochimica et Cosmochimica Acta, Volume 122

Author(s): Samuel V. Panno , Keith C. Hackley , Randall A. Locke , Ivan G. Krapac , Bracken Wimmer , Abbas Iranmanesh , Walton R. Kelly

Recently, brine samples from the Cambrian-age Mount Simon Formation (the deepest, most inaccessible sedimentary rock formation of the Illinois Basin) and the overlying Ironton–Galesville Formation were collected as part of a major research effort evaluating the feasibility of sequestration of carbon dioxide in deep geologic formations. Halide and halide/cation ratios (especially Cl/Br and Na/Br ratios) from groundwater samples collected during this investigation suggest that the brines of the Cambrian-age strata formed by the evaporation of seawater well beyond the point of halite precipitation. The Cl/Br and Na/Br ratios, the presence of Mississippi-Valley-Type (MVT) ore mineralization in close proximity to the Illinois Basin, and the tectonic history of the region and the Illinois Basin suggest that components of ore-forming brines and perhaps crystalline basement brine are likely still present within the Mount Simon Formation. Halide and cation/halide ratio plots show that these brines have mixed with and have been diluted by subaerially evaporated seawater, seawater and dilute groundwater. Movement of brines out of the Mount Simon Formation and/or exchange with brines of other formations is constrained by the overlying, siltstone- and shale-rich Eau Claire Formation, a low-permeability layer. The most plausible interpretation of the halide and halide/cation ratio data is that the brines of the Cambrian-age strata were introduced to the Illinois Basin from outside of the basin, perhaps when the Illinois Basin was connected to the Arkoma (Oklahoma and Arkansas) and Black Warrior Basins (Alabama and Mississippi) via the Reelfoot Rift during Cambrian and early Ordovician time. In addition, the presence of some percentage of high NaCl, low Cl/Br brines from the crystalline basement is suggested given the geochemical relationships of the halide and cation/halide ratios and the tectonic history of the Illinois Basin. Finally, halide and cation/halide ratios determined by this investigation, and regional geochemical evidence and hydrogeologic modeling (by others) suggest that the brines of these strata probably were affected by regional hydrothermal activity during Permian time that was responsible for the MVT ore deposits of the Midwestern U.S. Thus, the brines of the deepest strata of the Illinois Basin constitute a different, more complex type of fluid than those found elsewhere in the basin. Halide and halide-cation ratios suggest that these deep brines are dominated by residual evaporitic brine (possibly originating as ore-forming brines) with dilution by seawater and dilute groundwater. Other components may include subaerially evaporated seawater and crystalline basement brines.

• 10/1/2014
• 10/1/2014
• Publication date: 15 August 2014
Source:Geomorphology, Volume 219

Author(s): William L. Blewett , Scott A. Drzyzga , Laura Sherrod , Hong Wang

Data obtained from ground-penetrating radar (GPR), optically stimulated luminescence (OSL) dating, and geostatistical reconstructions of Lake Algonquin water planes indicate that high-standing outwash aprons flanking the Munising moraine's southern margin in eastern Upper Michigan terminate as large, coalescing Gilbert-type ice-contact deltas graded to the Main level of Lake Algonquin. Nearly 30km of GPR imagery provides clear evidence of topset and foreset beds diagnostic of deltaic deposition. Landform assemblages suggest that the deltas likely evolved from subaqueous grounding line fans formed along a retreating ice margin characterized by widespread stagnation. In time, these deltas aggraded to the Main Lake Algonquin level as the ice margin stabilized. An OSL date of 12.5±1.1ka on a nearby beach ridge associated with the Main Algonquin shoreline is consistent with this interpretation. These new data, coupled with the presence of nested fans at the downstream end of meltwater channels incised into the delta, indicate that Lake Algonquin was falling as delta deposition waned, eventually reaching a level concordant with the Lower Orillia level before final abandonment. Large, regionally extensive heads of outwash marking the crest of the Munising moraine are graded to the upper margins of these deltas and, by inference, must also correlate with Main Lake Algonquin and the associated Two Rivers deglaciation ca. 13–12.5ka. The deltas, in turn, are conspicuously crosscut by outwash aprons that are graded to levels much lower than any recognized upper group Lake Algonquin shoreline. Because these aforementioned heads of outwash, part of Drexler and others' Grand Marais moraine, correlate with the Marquette moraine farther west, they likely date to the Marquette advance ca. 11.5ka. Thus, landforms related to Two Rivers and to Marquette glaciations appear to comingle across the study area. In the absence of extensive exposures and datable materials, our work highlights the fact that crosscutting relationships and distinct differences in base level can provide an important first step for untangling the complicated landform relationships in this part of Michigan.

• Publication date: Available online 7 June 2014
Source:Cretaceous Research

Author(s): Nathan Barling , David M. Martill , Sam W. Heads , Florence Gallien

Fossil insects from the Lower Cretaceous (Aptian) Crato Formation of north-east Brazil are preserved as goethite replacements in laminated limestones of lacustro-lagoonal origin. They display remarkable degrees of morphological detail down to the macromolecular level in some examples. We document the fidelity of preservation and reveal an astonishing variety of morphological detail comparable in some instances with that found in amber inclusions.

• Publication date: 15 December 2013
Source:Electrochimica Acta, Volume 113

Author(s): Junhua Jiang , Lei Zhang , Xinying Wang , Nancy Holm , Kishore Rajagopalan , Fanglin Chen , Shuguo Ma

Woody biochar monolith with ultra-high carbon content and highly ordered macropores has been prepared via one-pot pyrolysis and carbonization of red cedar wood at 750°C without the need of post-treatment. Energy-dispersive spectroscope (EDX) and scanning electron microscope (SEM) studies show that the original biochar has a carbon content of 98wt% with oxygen as the only detectable impurity and highly ordered macroporous texture characterized by alternating regular macroporous regions and narrow porous regions. Moreover, the hierarchically porous biochar monolith has a high BET specific surface area of approximately 400m2 g−1. We have studied the monolith material as supercapacitor electrodes under acidic environment using electrochemical and surface characterization techniques. Electrochemical measurements show that the original biochar electrodes have a potential window of about 1.3V and exhibit typical rectangular-shape voltammetric responses and fast charging–discharging behavior with a gravimetric capacitance of about 14Fg−1. Simple activation of biochar in diluted nitric acid at room temperature leads to 7 times increase in the capacitance (115Fg−1). Because the HNO3-activation slightly decreases rather than increases the BET surface area of the biochar, an increase in the coverage of surface oxygen groups is the most likely origin of the substantial capacitance improvement. This is supported by EDX, X-ray photoelectron spectroscopy (XPS), and Raman measurements. Preliminary life-time studies show that biochar supercapacitors using the original and HNO3-activated electrodes are stable over 5000 cycles without performance decays. These facts indicate that the use of woody biochar is promising for its low cost and it can be a good performance electrode with low environmental impacts for supercapacitor applications.

• Publication date: March 2014
Source:Journal of Great Lakes Research, Volume 40, Issue 1

Author(s): Jody A. Peters , Matthew J. Cooper , Sara M. Creque , Matthew S. Kornis , Jeffrey T. Maxted , William L. Perry , Frederick W. Schueler , Thomas P. Simon , Christopher A. Taylor , Roger F. Thoma , Donald G. Uzarski , David M. Lodge

Despite increasing recognition of the importance of invertebrates, and specifically crayfish, to nearshore food webs in the Laurentian Great Lakes, past and present ecological studies in the Great Lakes have predominantly focused on fishes. Using data from many sources, we provide a summary of crayfish diversity and distribution throughout the Great Lakes from 1882 to 2008 for 1456 locations where crayfish have been surveyed. Sampling effort was greatest in Lake Michigan, followed by lakes Huron, Erie, Superior, and Ontario. A total of 13 crayfish species occur in the lakes, with Lake Erie having the greatest diversity (n=11) and Lake Superior having the least (n=5). Five crayfish species are non-native to one or more lakes. Because Orconectes rusticus was the most widely distributed non-native species and is associated with known negative impacts, we assessed its spread throughout the Great Lakes. Although O. rusticus has been found for over 100years in Lake Erie, its spread there has been relatively slow compared to that in lakes Michigan and Huron, where it has spread most rapidly since the 1990s and 2000, respectively. O. rusticus has been found in both lakes Superior and Ontario for 22 and 37years, respectively, and has expanded little in either lake. Our broad spatial and temporal assessment of crayfish diversity and distribution provides a baseline for future nearshore ecological studies, and for future management efforts to restore native crayfish and limit non-native introductions and their impact on food web interactions.

• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• Publication date: April 2014
Source:Journal of Archaeological Science, Volume 44

Author(s): Philip A. Slater , Kristin M. Hedman , Thomas E. Emerson

Archaeologists have long debated the role of regional interaction in the 11th to 14th centuries at the Mississippian polity of Cahokia. Architectural styles, exotic materials, and cultural objects provide indirect evidence for cultural interaction and ethnic and social diversity; however, identifying the movement of individuals (rather than materials) is key to our growing understanding of the population history that enabled the formation of this unique polity. This study is the first to use strontium isotope analysis (87Sr/86Sr) of human tooth enamel to identify immigrants at Cahokia. Modern and archaeological fauna were used to establish a baseline “local” range of strontium isotope ratios for the American Bottom region surrounding Cahokia. Teeth from individuals interred in diverse mortuary locations, including mounds, within this region were analyzed and compared to the local strontium isotope range to identify individuals of non-local origin. One-third of all individuals analyzed were identified as non-local, and the range and variability of their strontium ratios suggests multiple places of origin. The correlation of isotopic data with available biological and mortuary evidence allows us to examine the role of migration in the history of this Mississippian polity.

• Publication date: Available online 23 September 2014
Source:Journal of Great Lakes Research

Author(s): Greg G. Sass , Collin Hinz , Anthony C. Erickson , Nerissa N. McClelland , Michael A. McClelland , John M. Epifanio

Aquatic invasive species introductions are a global environmental concern. Negative effects of invasive species are often manifested in alterations of food web structure and through competition with and predation upon native species. The Illinois River, Illinois, USA harbors invasive, planktivorous bighead, Hypophthalmichthys nobilis, and silver carp, Hypophthalmichthys molitrix, and can be a model ecosystem to test for their effects on zooplankton communities. We tested for bighead and silver carp effects on zooplankton communities pre- and post-establishment within one reach of the Illinois River and among river reaches that varied in abundances of these invasive fishes. The establishment of bighead and silver carp was associated with increased rotifer abundances, while cladoceran and copepod abundances were reduced relative to pre-establishment. Cladoceran and copepod abundance and biomass were negatively associated with bighead and silver carp abundances among reaches. Total zooplankton and rotifer abundance and biomass were positively associated with bighead and silver carp abundances. Our results suggest that bighead and silver carp have changed the zooplankton community of the Illinois River which may have implications for the food web, native species, and other ecosystems poised to be invaded, such as the Laurentian Great Lakes.

• Publication date: Available online 20 June 2014
Source:Chemical Engineering Research and Design

Author(s): Qing Ye , Xinlei Wang , Yongqi Lu

A carbonate-based CO2 absorption process is currently under development that involves crystallizing potassium bicarbonate from a potassium carbonate/bicarbonate solution to form slurry used for stripping CO2 at high pressure. Kinetics of the bicarbonate crystallization process was investigated using a laboratory mixed suspension, mixed product removal (MSMPR) reactor. Effects of the mean residence time, agitation speed, relative supersaturation level, crystallization temperature, and suspension density on nucleation and growth rates of the bicarbonate crystals were quantified. The observed crystal population density distribution featured a size-dependent growth pattern. A three-parameter kinetic model was used for bicarbonate crystallization, and model parameters were determined by fitting the experimental data. Crystallization kinetics was applied to perform a preliminary analysis of the crystallizer design for the carbonate-based CO2 capture process.

• Publication date: 6 September 2014
Source:Chemical Engineering Science, Volume 116

Author(s): Xinhuai Ye , Yongqi Lu

Potassium carbonate–bicarbonate (K2CO3–KHCO3) aqueous solutions could be used as an alternative to amines as solvents in CO2 capture from the flue gas of coal-fired power plants. The rate of CO2 absorption into K2CO3–KHCO3 solutions is governed by the reaction between CO2 and $OH −$, which is first order with respect to both CO2 and $[ OH − ] ( r = k OH [ OH − ] [ CO 2 ] )$. Knowledge of the reaction kinetics and dynamic changes in kinetics along an absorber is essential for process design. However, this information, particularly the values of the rate constant of the reaction between CO2 and $OH −$, $k OH$, in K2CO3–KHCO3 solutions with different ionic strengths and CO2 loadings are seldom available in the literature. In this study, we investigated the kinetics of CO2 absorption into 5–40wt% solutions with different levels of CO2 loading at 25–80°C. The $k OH$ values were determined by measuring rates of CO2 absorption into the solutions in a stirred cell reactor and by using the classic Danckwerts theory for interpretation of the data. The method was validated by the good agreement between the rate constants obtained for infinitely dilute solutions and those reported in the literature. The CO2 loading of K2CO3–KHCO3 solutions was found to govern the activation energy (E a ) of the absorption reaction. In K2CO3–KHCO3 solutions with the same CO2 loading, the E a values were comparable, regardless of the concentration or total ionic strength of the solution. The E a decreased as the CO2 loading of the solution increased. The ionic strength of the solution substantially affected the Arrhenius pre-exponential factor term [ln(A)] of k OH. Functional formulae have been developed that can be readily used to calculate k OH for K2CO3–KHCO3 solutions with different levels of CO2 loading over the applicable range. The results provide extensive information on the kinetics of the CO2 reaction in K2CO3–KHCO3 solutions, particularly in concentrated solutions (20–40wt%) with a CO2 loading up to 40% of potassium carbonate to bicarbonate conversion at temperatures up to 80°C.

• 10/1/2014
• Publication date: July–August 2014
Source:Comptes Rendus Geoscience, Volume 346, Issues 7–8

Author(s): C. Blaine Cecil , William A. DiMichele , Scott D. Elrick

The Pennsylvanian portion of the Late Paleozoic Ice Age was characterized by stratigraphic repetition of chemical and siliciclastic rocks in the equatorial regions of the Pangean interior. Known as “cyclothems”, these stratigraphic successions are a 105 yr-record of glacial waxing and waning, superimposed on longer term, 106 yr intervals of global warming and cooling and a still longer term trend of increasing equatorial aridity. During periods of maximum ice–minimum sea level, the interior craton was widely exposed. Epicontinental landscapes were initially subjected to dry subhumid climate when first exposed, as sea level fell, but transitioned to humid climates and widespread wetlands during maximum lowstands. During interglacials (ice-minima) seasonally dry vegetation predominated. The wetland and seasonally dry biomes were compositionally distinct and had different ecological and evolutionary dynamics.

• Publication date: 1 September 2014
Source:Geomorphology, Volume 220

Author(s): Kory Allred , Wei Luo , Mike Konen , B. Brandon Curry

Ice-walled lake plains (IWLPs) are rounded, flat-topped mounds that formed in stagnant ice environments along the margins of the Laurentide Ice Sheet. We conducted detailed morphometric and statistical analyses of the shape, size, and orientation of more than 400 IWLPs identified from aerial photos aided with LiDAR data in DeKalb County, Illinois, USA. Lake elongation theories include extraterrestrial impact (e.g. the Carolina Bays), ice flow dynamics and crevasses, and wind induced currents that preferentially erode the shorelines perpendicular to the dominant wind direction. The results indicate that elliptical IWLPs with a perimeter greater than 3050m have preferred orientations roughly normal to the paleo-wind direction as indicated by contemporaneous parabolic dunes located 50km to the west. The orientations of the IWLPs with a perimeter less than 1220m are scattered and show no apparent trend. The IWLP orientation is not related to ice flow dynamics or glacial crevasses because no statistically significant relationship exists with regard to the ice flow as proxied by the moraine direction. The orientation of large IWLPs in DeKalb County are consistent with wind-induced lake elongation observed in modern permafrost thaw lakes, suggesting that the prevailing wind also played an important role in controlling the orientation of IWLPs during the last glacial period and led to the preferred orientation we see today.

• Publication date: 30 November 2013
Source:Electrochimica Acta, Volume 111

Author(s): Junhua Jiang , Xinying Wang , Lei Zhang

Nanoporous gold (NPG) microelectrodes with high surface area and open pore network were successfully prepared by applying modulated potential to a polycrystalline Au-disk microelectrode in ionic liquid electrolyte containing ZnCl2 at elevated temperature. During cathodic process, Zn is electrodeposited and interacted with Au microdisk substrate to form a AuZn alloy phase. During subsequent anodic process, Zn is selectively dissolved from the alloy phase, leading to the formation of a NPG layer which can grow with repetitive potential modulation. Scanning-electron microscope and energy dispersive X-ray microscope measurements show that the NPG microelectrodes possessing nanoporous structures can be tuned via potential modulation, and chemically contain a small amount of Zn whose presence has no obvious influence on electrochemical responses of the electrodes. Steady-state and cyclic voltammetric studies suggest that the NPG microelectrodes have high surface area and keep diffusional properties of a microelectrode. Electrochemical nitrite reduction and oxidation are studied as model reactions to demonstrate potential applications of the NPG microelectrodes in electrocatalysis and electroanalysis. These facts suggest that the potential-modulated electrochemical alloying/dealloying in ionic liquid electrolyte offers a convenient green-chemistry method for the preparation of nanoporous microelectrodes.

• Publication date: 1 February 2014
Source:Forest Ecology and Management, Volume 313

Author(s): Charles E. Flower , Lawrence C. Long , Kathleen S. Knight , Joanne Rebbeck , Joel S. Brown , Miquel A. Gonzalez-Meler , Christopher J. Whelan

Inadvertently introduced into North America in the 1990s, the invasive emerald ash borer (EAB, Agrilus planipennis) has been spreading across the Great Lakes Region resulting in widespread ash tree (Fraxinus spp.) mortality. Native woodpeckers and other bark-foraging insectivores represent one of the few potential natural predators of EAB in the U.S. In this study, we combined observational and destructive tree harvesting approaches to assess bark-foraging bird predation on EAB larvae in a deciduous forest of central Ohio. Results of our observational study show that in an EAB impacted forest, bark-foraging birds forage more heavily on ash trees than non-ash trees, and that they forage preferentially on ash trees that exhibit canopy decline symptoms relative those with healthy canopies. These patterns were further supported by the destructive sampling of 46 ash trees wherein predation by bark-foragers significantly reduced tree-level EAB densities by upwards of 85%. Bark-foraging predation intensity increased with increased EAB infestation levels, with bark-foragers harvesting ∼45% of EAB in trees with thinning canopies compared to ∼22% in ash trees with healthy canopies. Woodpeckers harvest EAB in a density-dependent pattern that could contribute to population control. Despite bark-forager predation, EAB had a high likelihood of successfully emerging from the heavily infested ash trees (∼30% or 35 EAB per m2). Our results suggest that woodpeckers and other bark-foragers may use visual canopy decline, and perhaps other cues, to target ash trees with increased EAB densities. Moreover, our results provide insight into the indirect effects of invasive species on biotic interactions in forest ecosystems highlighting potential shifts in bark-foraging and other bird behaviors in response to a novel forest pest. Bark-foragers respond to EAB infestation and may thus potentially help regulate EAB populations and their spread in a mixed deciduous forest. We suggest that maintaining snags and nesting sites during and after forest pest outbreaks may enhance populations of bark-foraging bird species and, thus, their biological control of pest insects in temperate deciduous forests.

• Bermond, Gerald; Cavigliasso, Fanny; Mallez, Sophie; et al. writer Bermond, Gerald; Cavigliasso, Fanny; Mallez, Sophie; et al. by Bermond, Gerald; Cavigliasso, Fanny; Mallez, Sophie; et al. published by Bermond, Gerald; Cavigliasso, Fanny; Mallez, Sophie; et al.
Title: No Clear Effect of Admixture between Two European Invading Outbreaks of Diabrotica virgifera virgifera in Natura
Author(s): Bermond, Gerald; Cavigliasso, Fanny; Mallez, Sophie; et al.
Source: PLOS ONE, 9 (8): AUG 29 2014
Document Type: Article
• 10/1/2014
• Nolan, David J.; Hickson, Robert N.; Kuehn, Steven R.; Branstner, Mark C. writer Nolan, David J.; Hickson, Robert N.; Kuehn, Steven R.; Branstner, Mark C. by Nolan, David J.; Hickson, Robert N.; Kuehn, Steven R.; Branstner, Mark C. published by Nolan, David J.; Hickson, Robert N.; Kuehn, Steven R.; Branstner, Mark C.
Midcontinental Journal of Archaeology; 10/01/2012
(AN 85351848)
America: History & Life
• Publication date: 30 January 2014
Source:Applied Surface Science, Volume 290

Author(s): Seyed A. Dastgheib , Jianli Ren , Massoud Rostam-Abadi , Ramsay Chang

A rapid method to prepare functionalized and metal-impregnated activated carbon from coal is described in this paper. A mixture of ferric chloride and a sub-bituminous coal was used to demonstrate simultaneous coal activation, chlorine functionalization, and iron/iron oxides impregnation in the resulting porous carbon products. The FeCl3 concentration in the mixture, the method to prepare the FeCl3-coal mixture (solid mixing or liquid impregnation), and activation atmosphere and temperature impacted the surface area and porosity development, Cl functionalization, and iron species impregnation and dispersion in the carbon products. Samples activated in nitrogen or a simulated flue gas at 600 or 1000°C for 1–2min had surface areas up to ∼800m2/g, bulk iron contents up to 18wt%, and surface chlorine contents up to 27wt%. Potential catalytic and adsorption application of the carbon materials was explored in catalytic wet air oxidation (CWAO) of phenol and adsorption of ionic mercury from aqueous solutions. Results indicated that impregnated activated carbons outperformed their non-impregnated counterparts in both the CWAO and adsorption tests.

• 10/1/2014
• Publication date: June 2014
Source:Fuel Processing Technology, Volume 122

Author(s): Brajendra K. Sharma , Bryan R. Moser , Karl E. Vermillion , Kenneth M. Doll , Nandakishore Rajagopalan

Pyrolysis of HDPE waste grocery bags followed by distillation resulted in a liquid hydrocarbon mixture with average structure consisting of saturated aliphatic paraffinic hydrogens (96.8%), aliphatic olefinic hydrogens (2.6%) and aromatic hydrogens (0.6%) that corresponded to the boiling range of conventional petroleum diesel fuel (#1 diesel 190–290°C and #2 diesel 290–340°C). Characterization of the liquid hydrocarbon mixture was accomplished with gas chromatography–mass spectroscopy, infrared and nuclear magnetic resonance spectroscopies, size exclusion chromatography, and simulated distillation. No oxygenated species such as carboxylic acids, aldehydes, ethers, ketones, or alcohols were detected. Comparison of the fuel properties to the petrodiesel fuel standards ASTM D975 and EN 590 revealed that the synthetic product was within all specifications after addition of antioxidants with the exception of density (802kg/m3). Notably, the derived cetane number (73.4) and lubricity (198μm, 60°C, ASTM D6890) represented significant enhancements over those of conventional petroleum diesel fuel. Other fuel properties included a kinematic viscosity (40°C) of 2.96mm2/s, cloud point of 4.7°C, flash point of 81.5°C, and energy content of 46.16MJ/kg. In summary, liquid hydrocarbons with appropriate boiling range produced from pyrolysis of waste plastic appear suitable as blend components for conventional petroleum diesel fuel.

### Graphical abstract

• Publication date: December 2014
Source:Soil Biology and Biochemistry, Volume 79

Author(s): Minjie Yao , Junpeng Rui , Jiabao Li , Yumei Dai , Yongfei Bai , Petr Heděnec , Junming Wang , Shiheng Zhang , Kequan Pei , Chi Liu , Yanfen Wang , Zhili He , Jan Frouz , Xiangzhen Li

Serious nitrogen (N) deposition in terrestrial ecosystems causes soil acidification and changes the structure and function of the microbial community. However, it is unclear how these changes are dependent on N deposition rates, other factors induced by N (e.g., pH), and their interactions. In this study, we investigated the responses of soil prokaryotic community structure and stability after a 13-year N addition in the semi-arid Leymus chinensis steppe in Inner Mongolia, China. Our results demonstrated that the prokaryotic community structure changed at the low N addition rate of 1.75 g N m−2 yr−1; however, dramatic changes in microbial abundance, respiratory quotient, and prokaryotic diversity occurred at N addition rates of more than 5.25 g N m−2 yr−1 when the soil pH dropped below 6.0. The two patterns indicated the difference in driving forces for different microbial properties. The N-driven and pH-driven processes are likely the most important mechanisms determining the responses of bacterial community to N. Some copiotrophic/oligotrophic bacteria, e.g., Proteobacteria and Acidobacteria, changed their relative abundances with the N addition continuously even at a low rate, indicating that they were more sensitive to N directly. Some bacterial groups significantly changed their relative abundance at a high N addition rate when pH dropped below 6.0, e.g., Verrucomicrobia and Armatimonadetes, indicating that they were more sensitive to pH below 6.0. N addition altered the prokaryotic community structure through enrichment of copiotrophic bacteria (species adjustment) at low N addition rates and through enrichment of nitrophilous taxa and significant loss of diversity at high N rates. The results also demonstrated that a high N addition diminished the stability of the prokaryotic community structure and activity through reduction in species diversity and bacterial interaction. Overall, this study supported the hypothesis that the responses of prokaryota to N were dependent on deposition rates, and N-driven and pH-driven processes were the important mechanisms to control the shift of the prokaryotic community.

• Mazrim, Robert F. writer Mazrim, Robert F. by Mazrim, Robert F. published by Mazrim, Robert F.
Midcontinental Journal of Archaeology; 04/01/2011
(AN 65100783)
America: History & Life
• 10/1/2014
• Publication date: 15 November 2013
Source:Quaternary Science Reviews, Volume 80

Author(s): Hong Wang , Andrew J. Stumpf , Xiaodong Miao

• 10/1/2014
• Publication date: February 2014
Source:Ecotoxicology and Environmental Safety, Volume 100

Author(s): Samantha K Carpenter , Nohra E. Mateus-Pinilla , Kuldeep Singh , Andreas Lehner , Damian Satterthwaite-Phillips , Robert D. Bluett , Nelda A. Rivera , Jan E. Novakofski

The North American river otter (Lontra canadensis) is a biomonitor for organohalogenated compounds (OHCs) associated with a wide range of deleterious health effects in wildlife and humans. We determined concentrations of twenty OHCs in livers of 23 river otters salvaged by the Illinois Department of Natural Resources from 2009 to 2011, determined sex-dependent distribution of OHCs, and compared our results to the reported concentrations of four OHCs in Illinois river otters from 1984 to 1989. Since these contaminants have been banned for over 30 years, we predicted smaller mean concentrations than those previously reported in Illinois otters. We detected eleven of twenty OHCs; PCBs (polychlorinated biphenyls), dieldrin, and 4,4′-DDE (dichlorodiphenyldichloroethylene) were present in the greatest mean concentrations. We report the largest mean concentration of dieldrin to date in the liver of North American river otters (mean: 174, range: 14.4–534 parts per billion wet wt [ppb]). Mean PCB concentrations were significantly higher in males (mean: 851; range: 30–3450ppb) than females (mean: 282; range: 40–850ppb; p=0.04). Mean concentrations of dieldrin were greater than those detected in otters from 1984 to 1989 (mean: 90; range: 30–130ppb; p&lt;0.05). Our results suggest OHC exposure remains a concern. Future research in Illinois should focus on evaluating OHCs exposures, particularly dieldrin, at the watershed level.

• Publication date: May 2014
Source:Earth-Science Reviews, Volume 132

Author(s): Zhongcheng Jiang , Yanqing Lian , Xiaoqun Qin

Rocky desertification, which is relatively less well known than desertification, refers to the processes and human activities that transform a karst area covered by vegetation and soil into a rocky landscape. It has occurred in various countries and regions, including the European Mediterranean and Dinaric Karst regions of the Balkan Peninsula, Southwest China on a large scale, and alarmingly, even in tropical rainforests such as Haiti and Barbados, and has had tremendous negative impacts to the environment and social and economic conditions at local and regional scales. The goal of this paper is to provide a thorough review of the impacts, causes, and restoration measures of rocky desertification based on decades of studies in the southwest karst area of China and reviews of studies in Europe and other parts of the world. The low soil formation rate and high permeability of carbonate rocks create a fragile and vulnerable environment that is susceptible to deforestation and soil erosion. Other natural processes related to hydrology and ecology could exacerbate rocky desertification. However, disturbances from a wide variety of human activities are ultimately responsible for rocky desertification wherever it has occurred. This review shows that reforestation can be successful in Southwest China and even in the Dinaric Karst region when the land, people, water, and other resources are managed cohesively. However, new challenges may arise as more frequent droughts and extreme floods induced by global climate change and variability may slow the recovery process or even expand rocky desertification. This review is intended to bring attention to this challenging issue and provide information needed to advance research and engineering practices to combat rocky desertification and to aid in sustainable development.

• Publication date: February 2014
Source:Journal of Applied Geophysics, Volume 101

Author(s): Ahmed Ismail , Andrew Stumpf , Robert Bauer

The vertical distribution of compressional wave velocity (Vp) and shear wave velocity (Vs) acquired from fifteen boreholes in central Illinois using the standard surface-source downhole-receiver method was studied. The velocity logs were compared with lithologic logs and gamma-ray logs acquired from the same boreholes to: 1) better understand the Vp and Vs ranges and variations within glacial sediments, 2) determine whether characteristic seismic velocities could be resolved to distinguish among the three major Pleistocene glaciations of Wisconsin (WI), Illinois (IL), and pre-Illinois (PIL), and 3) examine velocity variations corresponding to heterogeneities in the sediments composing these three major units. Results showed that deposits composing these units had highly variable Vp and Vs values. Only the contact between deposits of the WI and IL episodes could be delineated by a corresponding slight decrease in Vp. Other than that, neither Vp nor Vs logs showed significant contrasts at the contacts between these units. Some individual sediment packages, or intraunits, exhibited distinctive velocity patterns in the study area and were identified more clearly from Vs than from Vp logs. These intraunits are Wisconsin tills (T), Vandalia till (GV) and Mahomet sand (BM).

• Publication date: March 2014
Source:Journal of Great Lakes Research, Volume 40, Issue 1

Author(s): Joshua D. Dub , Rebecca A. Redman , David H. Wahl , Sergiusz J. Czesny

Yellow perch have experienced widespread recruitment failure within Lake Michigan since the early 1990s. Efforts to explain annual recruitment variability have primarily focused on the first year of growth, while the juvenile life stage has largely been neglected. Juvenile yellow perch, age-0 through age-2, were collected annually from 2006–2010 in Illinois waters of Lake Michigan to assess temporal variability of size-at-age and size-selective mortality. Age-0 and age-2 total length at capture differed significantly between years with a maximum difference of 4.4mm and 11.2mm, respectively. First winter size-selective mortality was not observed for any year-class, however size-specific growth, with larger individuals growing faster than smaller counterparts, occurred during the first winter for all year-classes but 2006. Size-selective mortality was documented between age-1 and age-2 of the 2006 year-class with yellow perch less than 70mm at age-1 not surviving through age-2. Though population level effects remain unknown, size-specific growth and mortality during the juvenile life stage may influence the size structure and year-class strength of yellow perch in southwestern Lake Michigan. Identification of size-selective mortality occurring beyond the first growing season highlights the significance of rapid growth during early life and the importance of investigating whole life stages to identify factors influencing year-class strength.

• Fischel, Richard L.; Wisseman, Sarah U.; Hughes, Randall E.; Emerson, Thomas E. writer Fischel, Richard L.; Wisseman, Sarah U.; Hughes, Randall E.; Emerson, Thomas E. by Fischel, Richard L.; Wisseman, Sarah U.; Hughes, Randall E.; Emerson, Thomas E. published by Fischel, Richard L.; Wisseman, Sarah U.; Hughes, Randall E.; Emerson, Thomas E.
Midcontinental Journal of Archaeology; 10/01/2010
(AN 56673017)
America: History & Life
• 10/1/2014
• Publication date: August 2014
Source:Zoology, Volume 117, Issue 4

Author(s): John W. Rowe , Brittany J. Miller , Mark A. Stuart , Cassandra Snyder , John K. Tucker , David L. Clark , Lawrence W. Wittle , James T. Lamer

Background color convergence of prey occurring through local adaptation or phenotypically plastic responses can reduce predation rates by visual predators. We assessed the capacity for substrate color-induced melanization in eight turtle species within the groups Chelydridae, Emydidae, Kinosternidae, and Trionychidae by rearing individuals on black or white substrates for 160 days. In all aquatic turtle species, integuments of the head and carapace of the individuals that were reared on a black substrate were darker than of those reared on a white substrate. In the terrestrial turtle Terrapene carolina carolina, however, no significant differences in dorsal head skin or carapace color were observed between treatments. Histological examination of tail tips in three aquatic species (Chelydra serpentina serpentina, Graptemys geographica, and Trachemys scripta elegans) indicated that substrate color-induced melanization is morphological, involving the transfer of melanosomes from basal epidermal melanocytes to adjacent keratinocytes. Interestingly, substrate color-induced melanization in a previously studied Pleurodire species apparently involves physiological color change. We could not, however, rule out physiological components to color change in the turtles of our study.

• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• 10/1/2014
• Publication date: February 2014
Source:Animal Behaviour, Volume 88

Author(s): Michael P. Ward , Mark Alessi , Thomas J. Benson , Scott J. Chiavacci

Most birds are socially monogamous, diurnally active and have small home ranges. These birds occasionally undertake extraterritorial forays, presumably to seek extrapair copulations. We used automated radiotelemetry to examine nocturnal forays and activity of a diurnal, socially monogamous passerine, the yellow-breasted chat, Icterina virens. Males and females forayed during both day and night, but night forays were more common. In addition to varying between day and night, there were sex- and breeding-stage-specific differences in foraying behaviour. Males forayed more than females and more frequently when their female was not fertile. Conversely, females primarily forayed when fertile. We suggest that females foray at night to avoid detection, because their mate's knowledge of potential extrapair copulations may result in harassment or decreased parental care. Both sexes were nocturnally active; however, the activity of males peaked when their mates were fertile, probably to prevent their mates from foraying and guarding them from foraying males. The nocturnal behaviour of chats suggest that extraterritorial forays may be more common than previously thought and that nocturnal behaviours may be crucial for understanding the strategies males and females use to acquire extrapair copulations.

• 10/1/2014
• 10/1/2014
• 10/1/2014
• Publication date: 1 January 2014
Source:Preventive Veterinary Medicine, Volume 113, Issue 1

Author(s): Mary Beth Manjerovic , Michelle L. Green , Nohra Mateus-Pinilla , Jan Novakofski

Strategies to contain the spread of disease often are developed with incomplete knowledge of the possible outcomes but are intended to minimize the risks associated with delaying control. Culling of game species by government agencies is one approach to control disease in wild populations but is unpopular with hunters and wildlife enthusiasts, politically unpalatable, and erodes public support for agencies responsible for wildlife management. We addressed the functional differences between hunting and government culling programs for managing chronic wasting disease (CWD) in white-tailed deer by comparing prevalence over a 10-year period in Illinois and Wisconsin. When both Illinois and Wisconsin were actively culling from 2003 – 2007, there were no statistical differences between state CWD prevalence estimates. Wisconsin government culling concluded in 2007 and average prevalence over the next five years was 3.09 ± 1.13% with an average annual increase of 0.63%. During that same time period, Illinois continued government culling and there was no change in prevalence throughout Illinois. Despite its unpopularity among hunters, localized culling is a disease management strategy that can maintain low disease prevalence while minimizing impacts on recreational deer harvest.

• Publication date: 15 April 2014
Source:Quaternary Science Reviews, Volume 90

Author(s): B. Brandon Curry , Edwin R. Hajic , James A. Clark , Kevin M. Befus , Jennifer E. Carrell , Steven E. Brown

Evidence of the Kankakee Torrent (Ekblaw and Athy, 1925) includes boulder bars formed on a scoured bedrock surface west of Kankakee, Illinois, and overflow channels that connect several moraine-dammed basins (Wauponsee, Watseka, and Pontiac; Willman and Payne, 1942). Geomorphic evidence of a large scale flood event in the Illinois Valley includes features such as erosional residuals (Hajic, 1990). The age of the Kankakee Torrent is about 19,000 cal yr BP based on the pooled mean of four radiocarbon ages of tundra plant stems and leaves from the Oswego channel complex (median probability = 18,930 cal yr BP, σ1 range, 18,870–18,970 cal yr BP). Analysis of recently obtained sediment cores from the middle Illinois River valley near Havana, Illinois, has revealed the bedrock surface is defended by a mantle of bouldery debris buried by 15 m of mostly slackwater lake sediment. Radiocarbon ages of needles archived in the lake sediment reveal evidence for an early lake phase that post-dates the Kankakee Torrent (18,030–17,530 cal yr BP) and a later lake phase (15,690–13,040 cal yr BP). The radiocarbon ages indicate that the deeply buried bouldery rubble was deposited by the Kankakee Torrent. Consideration of isostasy indicates that the earlier lake phase at Havana may have been associated with downward flexure of land surface in response to glacier loading. The younger lake phase was caused in part by deposition of a sediment dam (the Savanna–Deer Plain terrace) at the mouth of the Illinois River. The lake shoaled due to passing of the isostatic forebulge across the area.

• 10/1/2014
• Publication date: 15 August 2014
Source:Science of The Total Environment, Volume 490

Author(s): Ya Zhang , Walton R. Kelly , Samuel V. Panno , Wen-Tso Liu

Fecal contamination in Midwestern karst regions was evaluated by simultaneously measuring traditional bacterial indicators (coliforms and Escherichia coli), Bacteroidales-based biomarkers, and environmental variables. Water samples from springs and wells were collected from karst regions in Illinois (IL), Wisconsin (WI), Kentucky (KY), and Missouri (MO). Quantitative PCR (Q-PCR) with seven primer sets targeting different members of Bacteroidales was used to determine the origin of fecal contamination (i.e., from human waste, livestock waste, or both). Most samples were contaminated by both human and animal waste, with a few samples showing pollution solely by one or the other. Spring water tended to have higher levels of contamination than well water, and higher concentrations of fecal biomarkers were detected in urban springs compared to rural spring systems. However, there were discrepancies on contamination profile determined by Bacteroidales-based biomarkers and by traditional bacterial indicators. Among all the environmental parameters examined, E. coli, sulfate, total dissolved solids (TDS), and silicon were significantly correlated (p &lt;0.05) with the level of Bacteroidales-based fecal indicators. A rapid screening method using total nitrogen (TN) and chloride (Cl) concentrations to determine fecal contamination was shown to be effective and correlated well with Bacteroidales-based MST. The results suggest that human and livestock feces co-contaminated a large portion of karst groundwater systems in Midwestern regions, and the inclusion of traditional bacterial indicators, environmental variables, and Bacteroidales-based MST is an effective approach for identifying fecal contamination in karst regions.

### Graphical abstract

• Branstner, Mark C. writer Branstner, Mark C. by Branstner, Mark C. published by Branstner, Mark C.
Midcontinental Journal of Archaeology; 10/01/2012
(AN 85351843)
America: History & Life
• Publication date: Available online 8 July 2014
Source:Arthropod Structure &amp; Development

Author(s): Mei Su , Christopher H. Dietrich , Yalin Zhang , Wu Dai

Previous studies of insect spermatozoa indicate that these specialized cells have undergone significant morphological evolution and exhibit traits useful for reconstructing phylogenetic relationships. Although leafhoppers (Cicadellidae) are among the largest and most economically important insect families, few comparative studies of their spermatozoa have been published. Here, the ultrastructure of mature spermatozoa of two leafhoppers Psammotettix striatus (Linnaeus) and Exitianus nanus (Distant), representing two different tribes of the largest leafhopper subfamily, Deltocephalinae, was examined by light and transmission electron microscopy. The shape and ultrastructure of spermatozoa of the two species are very similar to those of other Cicadellidae as well as other Auchenorrhyncha, comprising a conical acrosome invaginated to form a subacrosomal space, a filiform homogeneously condensed nucleus, a lamellate centriolar adjunct connecting the nucleus with the mid-piece/flagellum, a long flagellum with a 9 + 9 + 2 axoneme pattern and two symmetrical mitochondrial derivatives with an orderly array of peripheral cristae, and two drop-shaped accessory bodies. They may be distinguished by the size of the sperm, and the shape of the nucleus, accessory bodies, and paracrystalline region of mitochondrial derivatives. The fine morphology and ultrastructure of spermatozoon in P. striatus and E. nanus are illustrated, along with a brief discussion of the implications for classification and phylogenetic analyses of the subfamily.

• Fishel, Richard L. writer Fishel, Richard L. by Fishel, Richard L. published by Fishel, Richard L.
Midcontinental Journal of Archaeology; 10/01/2012
(AN 85351849)
America: History & Life
• Publication date: July 2014
Source:Ocean &amp; Coastal Management, Volume 95

Author(s): Bingjun Liu , Shulan Yan , Xiaohong Chen , Yanqing Lian , Yanbo Xin

The Modaomen Waterway (MW), a major outlet of the Pearl River Estuary, is a crucial source of water supply for Macao and Zhuhai City in Southern China. This waterway is frequently affected by saltwater intrusion from the South Sea, which has caused serious water shortage in recent years. For the planning and management of water supply at this waterway it is necessary to understand the characteristics of saltwater intrusion particularly in the low flow period of the year. However, as a result of multiple impacts from tide, river discharge, wind, topography, channel bathometry, and some other factors, the saltwater intrusion into this waterway is highly non-linear. In order to account for the non-linear characteristics, the wavelet method was used to analyze the period characteristics of tidal range, river discharge, and salinity and the impact of tidal range and river discharge on the salinity. Results show that the tidal range at Sanzao station and the salinity at Pinggang station both exhibit a stable 14.8-day period and the salinity in the MW is largely impacted by the tidal range during low stream flow periods. River flows from upstream of the waterway don't show any stable period characteristic, it, however, is critical in mitigating the salinity for water supply during saltwater intrusion. A minimum total flow of 2 500 m3/s from upstream at Sanshui and Makou stations has been practiced as a threshold for safe water supply. This study has found that the percent time when salinity is below the maximum permissible salinity of 250 ml/g for water supply increases as the river discharge from upstream increases and up to 50–70% of the time the salinity at water supply pumping station is below 250 mg/l when the upstream flow is greater than 2 500 m3/s. Planning and management of water supply operation at the MW is politically, economically and mostly importantly technically challenging, findings from this study can provide some guidance for operation and further research. For example, the phase lag of average salinity to tidal range was quantified to be 3.4–3.8 days. This phase lag time would suggest that the pumping operation to store freshwater in the backup storages needs to be at least 4–5 days ahead of the spring tide so as to avoid serious impact from saltwater intrusion. Safer water supply strategies can be developed by scheduling reservoir operations to maintain the threshold stream flow and the pumping.

• 10/1/2014

PRAIRIE RESEARCH INSTITUTE
William W. Shilts, Executive Director
607 E. Peabody Drive, MC-700
Champaign, IL 61820
Phone: 217-333-5111
Fax: 217-265-4678
webmaster@isgs.illinois.edu