bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluoride Complexation of Element 104, Rutherfordium (Rf), Investigated by Cation-exchange Chromatography
Authors: Ishii Yasuo , Toyoshima Atsushi , Tsukada Kazuaki , Asai Masato , Toume Hayato , Nishinaka Ichiro , Nagame Yuichiro , Miyashita Sunao , Mori Tomotaka , Suganuma Hideo , Haba Hiromitsu , Sakamaki Masami , Goto Shin-ichi , Kudo Hisaaki , Akiyama Kazuhiko , Oura Yasuji , Nakahara Hiromichi , Tashiro Yuki , Shinohara Atsushi , Schädel Matthias , Brüchle Willy , Pershina Valeria , Kratz Jens V 
Published: February 2008

Abstract
We report on new and much more precise cation-exchange data of element 104, rutherfordium (Rf), in the fluoride ion concentration [F−] range of 5.29×10−5−1.04×10−3 M. The result based on one-atom-at-a-time chemistry clearly demonstrates that the distribution coefficients (Kd) decrease with increasing [F−], suggesting successive fluoride complexation of Rf. The complexation of Rf is briefly discussed in terms of fully relativistic density functional calculation theory.
LIESST Effect and Cooperativity of a 2-D Hofmann-type Compound
Authors: Nakao Koji , Hayami Shinya , Akita Motoko , Inoue Katsuya 
Published: February 2008

Abstract
2-D Hofmann-type compound [Fe(4-phpy)2Ni(CN)4]·H2O (4-phpy = 4-phenylpyridine) was synthesized and characterized by magnetic susceptibility measurements. The compound exhibited spin-crossover behavior with thermal hysteresis loop and LIESST effect. The activation energy and the tunneling rate constant were estimated as Ea=773 (cm−1) and kHL(T→0)=4.51×10−6 (s−1) for the compound.
Fabrication of WO3 Nanoflakes by a Dealloying-based Approach
Authors: Liu Zhifu , Yamazaki Toshinari , Shen Yanbai , Meng Dan , Kikuta Toshio , Nakatani Noriyuki 
Published: February 2008

Abstract
We demonstrate the fabrication of WO3 nanoflakes by dealloying with subsequent thermal oxidation. Sputtered amorphous W0.68Cu0.32 alloy films were dealloyed in HNO3 solution where Cu was selectively removed and W self-assembled into cross-linked cubic phase W nanoflakes. This kind of W nanoflakes was transformed to monoclinic WO3 nanoflakes by thermal oxidation at 500 °C. Gas sensor made using the WO3 nanoflakes showed promising NO2-sensing performance.
Aspartic Acid-derived Wear-preventing and Friction-reducing Agents for Ionic Liquids
Authors: Minami Ichiro , Watanabe Naoko , Nanao Hidetaka , Mori Sigeyuki , Fukumoto Kenta , Ohno Hiroyuki 
Published: February 2008

Abstract
The first additives that improve the tribological properties of ionic liquids were designed. They were evaluated by a ball-on-flat type tribo-test under reciprocating motion. Tetraalkylammonium and tetraalkylphosphonium salts of N-protected aspartic acid was dissolved in 1-alkyl-3-methylimidzolium bis(trifluoromethylsulfonyl)imide. They prevented wear remarkably and reduced friction considerably. The salt of N-protected glutamic acid prevented wear but did not reduce friction under the conditions we have evaluated. A new model of boundary film composed of liquid clathrate structure is proposed herein.
Call Center Outsourcing: Coordinating Staffing Level and Service Quality
Authors: Ren Z. Justin , Zhou Yong-Pin 
Published: February 2008

In this paper, we study the contracting issues in an outsourcing supply chain consisting of a user company and a call center that does outsourcing work for the user company. We model the call center as a G/G/s queue with customer abandonment. Each call has a revenue potential, and we model the call center's service quality by the percentage of calls resolved (revenue realized). The call center makes two strategic decisions: how many agents to have and how much effort to exert to achieve service quality. We are interested in the contracts the user company can use to induce the call center to both staff and exert effort at levels that are optimal for the outsourcing supply chain (i.e., chain coordination). Two commonly used contracts are analyzed first: piecemeal and pay-per-call-resolved contracts. We show that although they can coordinate the staffing level, the resulting service quality is below system optimum. Then, depending on the observability and contractibility of the call center's effort, we propose two contracts that can coordinate both staffing and effort. These contracts suggest that managers pay close attention to service quality and its contractibility in seeking call center outsourcing.
Service-Level Differentiation in Call Centers with Fully Flexible Servers
Authors: Gurvich Itay , Armony Mor , Mandelbaum Avishai 
Published: February 2008

We study large-scale service systems with multiple customer classes and many statistically identical servers. The following question is addressed: How many servers are required (staffing) and how does one match them with customers (control) to minimize staffing cost, subject to class-level quality-of-service constraints? We tackle this question by characterizing scheduling and staffing schemes that are asymptotically optimal in the limit, as system load grows to infinity. The asymptotic regimes considered are consistent with the efficiency-driven (ED), quality-driven (QD), and quality-and-efficiency-driven (QED) regimes, first introduced in the context of a single-class service system. Our main findings are as follows: (a) Decoupling of staffing and control, namely, (i) staffing disregards the multiclass nature of the system and is analogous to the staffing of a single-class system with the same aggregate demand and a single global quality-of-service constraint, and (ii) class-level service differentiation is obtained by using a simple idle-server-based threshold-priority (ITP) control (with state-independent thresholds); and (b) robustness of the staffing and control rules: our proposed single-class staffing (SCS) rule and ITP control are approximately optimal under various problem formulations and model assumptions. Particularly, although our solution is shown to be asymptotically optimal for large systems, we numerically demonstrate that it performs well also for relatively small systems.
Genetics of the Musculoskeletal System: A Pleiotropic Approach
Authors: Karasik David , Kiel Douglas P 
Published: February 2008

Abstract
The risk of osteoporotic fracture can be viewed as a function of loading conditions and the ability of the bone to withstand the load. Skeletal loads are dominated by muscle action. Recently, it has become clear that bone and muscle share genetic determinants. Involution of the musculoskeletal system manifests as bone loss (osteoporosis) and muscle wasting (sarcopenia). Therefore, the consideration of pleiotropy is an important aspect in the study of the genetics of osteoporosis and sarcopenia. This Perspective will provide the evidence for a shared genetic influence on bone and muscle. We will start with an overview of accumulating evidence that physical exercise produces effects on the adult skeleton, seeking to unravel some of the contradictory findings published thus far. We will provide indications that there are pleiotropic relationships between bone structure/mass and muscle mass/function. Finally, we will offer some insights and practical recommendations as to the value of studying shared genetic factors and will explore possible directions for future research. We consider several related questions that together comprise the general paradigm of bone responses to mechanical loading and the relationship between muscle strength and bone parameters, including the genetic factors that modulate these responses. We believe that further progress in understanding the common genetic etiology of osteoporosis and sarcopenia will provide valuable insight into important biological underpinnings for both conditions and may translate into new approaches to reduce the burdens of both conditions through improved diagnosis, prevention, and early targeted treatment.
Nitrate‐Nitrogen Concentrations in the Perched Ground Water under Seepage‐Irrigated Potato Cropping Systems
Authors: Munoz‐Arboleda F. , Mylavarapu R. , Hutchinson C. , Portier K. 
Published: February 2008

AbstractExcessive nitrogen rates for potato production in northeast Florida have been declared as a potential source of nitrate pollution in the St. Johns River watershed. This 3‐yr study examined the effect of N rates (0, 168, and 280 kg ha−1) split between planting and 40 d after planting on the NO3–N concentration in the perched ground water under potato (Solanum tuberosum cv. Atlantic) in rotation with sorghum sudan grass hybrid (Sorghum vulgare × Sorghum vulgare var. sudanese, cv. SX17), cowpea (Vigna unguiculata cv. Iron Clay), and greenbean (Phaseolus vulgare cv. Espada). Soil solution from the root zone and water from the perched ground water under potato were sampled periodically using lysimeters and wells, respectively. Fertilization at planting increased the NO3–N concentration in the perched ground water, but no effect of the legumes in rotation with potatoes on nitrate leaching was detected. Fertilization of green bean increased NO3–N concentration in the perched ground water under potato planted in the following season. The NO3–N concentration in the soil solution within the potato root zone followed a similar pattern to that of the perched ground water but with higher initial values. The NO3–N concentration in the perched ground water was proportional to the rainfall magnitude after potato planting. A significant increase in NO3–N concentration in the perched ground water under cowpea planted in summer after potato was detected for the side‐dressing of 168 kg ha−1 N applied to potato 40 d after planting but not at the 56 kg ha−1 N side‐dress. Elevation in NO3–N concentration in the perched ground water under sorghum was not significant, supporting its use as an effective N catch crop.
Chemical and Isotopic Compositions of the Minjiang River, A Headwater Tributary of the Yangtze River
Authors: Li Xiao‐Dong , Masuda Harue , Liu Cong‐Qiang 
Published: February 2008

AbstractWe describe the anthropogenic impacts on the major dissolved elements (Cl−, NO3−–N, SO42−, and Na+) in the water from the Minjiang River (a headwater tributary of the Yangtze River) and upper Yangtze River in relation to increasing human activity. The major element chemistry and hydrogen, oxygen, and sulfur isotopic compositions were investigated. When the Minjiang River flows through the populated Sichuan Basin, the concentrations of Cl−, NO3−–N, SO42−, and Na+ gradually increase. The increasing SO42− in the highly polluted Minjiang River had high δ34S values (+6.3 to approximately +13.6‰), implicating the anthropogenic sources of sulfur from air pollutants, domestic wastewater, industrial effluents, and agricultural fertilizers. The water quality of the upper Yangtze River does not worsen after receiving the Minjiang River because the water from the lightly polluted Jinshajiang River contributes most of the total flux in the Yangtze River. However, these rivers deserve attention and further research because the Yangtze River is the most important river in China in terms of water quality.
Evaluation of Phosphorus Characterization in Broiler Ileal Digesta, Manure, and Litter Samples: 31P‐NMR vs. HPLC
Authors: Leytem A. B. , Kwanyuen P. , Plumstead P. W. , Maguire R. O. , Brake J. 
Published: February 2008

AbstractUsing 31‐phosphorus nuclear magnetic resonance spectroscopy (31P‐NMR) to characterize phosphorus (P) in animal manures and litter has become a popular technique in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with 31P‐NMR compared to other accepted methods such as high performance liquid chromatography (HPLC). To evaluate the use of 31P‐NMR to quantify myo‐inositol hexakisphosphate (phytate) in ileal digesta, manure, and litter from broilers, we compared results obtained from both 31P‐NMR and a more traditional HPLC method. The quantification of phytate in all samples was very consistent between the two methods, with linear regressions having slopes ranging from 0.94 to 1.07 and r2 values of 0.84 to 0.98. We compared the concentration of total monoester P determined with 31P‐NMR with the total inositol P content determined with HPLC and found a strong linear relationship between the two measurements having slopes ranging from 0.91 to 1.08 and r2 values of 0.73 to 0.95. This suggests that 31P‐NMR is a very reliable method for quantifying P compounds in manure/litter samples.
Fluorescence Imaging Applied to Tracer Distributions in Variably Saturated Fractured Clayey Till
Authors: Rosenbom Annette E. , Ernstsen Vibeke , Flühler Hannes , Jensen Karsten H. , Refsgaard Jens Christian , Wydler Hannes 
Published: February 2008

AbstractThe study of mechanisms controlling preferential flow and transport in variably saturated fractured clayey till is often hindered by insufficient spatial resolution or unknown measuring volume. With the objective to study these mechanisms while circumventing the obstacles, tracer experiments with two fluorescent tracers Acid Yellow 7 (AY7) and Sulforhodamine B (SB) were performed at three different rain events for a fall and a summer season. Irrigated areas were excavated down to depths of 2.8 m and the movement of both tracers in the exposed profiles was delineated simultaneously by high spatial resolution apparent concentration maps (pixel ∼1 mm2) obtained with an imaging device. The device consists of a light source and a CCD camera, both equipped with tracer‐specific‐filters for fluorescent light. The fluorescence images were corrected for nonuniform lighting, changing surface roughness, and varying optical properties of the soil profile. The resulting two‐dimensional apparent concentration distribution profiles of the tracers showed that: (i) relative low water content in the upper 10 cm of the irrigated till in summer had a pronounced retardation effect on the AY7‐migration and no effect on the SB‐migration; (ii) the dead‐end biopores were not activated in the fall season; (iii) only 3D fracture‐plans connected to hydraulically active 1D‐biopores contributed to the leaching; (iv) the tracer migration primary followed macropores during both seasons, though AY7 also followed a topsoil piston transport in summer; (v) the highest tracer pixel apparent concentrations were often found in macropores and most pronounced in the summer season; and (vi) 3D‐dilution in fractures seems to play a dominating role in AY7‐migration in the fall season.
Effects of Elevated Atmospheric CO2 on Invasive Plants: Comparison of Purple and Yellow Nutsedge (Cyperus rotundus L. and C. esculentus L.)
Authors: Rogers H. H. , Runion G. B. , Prior S. A. , Price A. J. , Torbert H. A. , Gjerstad D. H. 
Published: February 2008

AbstractThe rise in atmospheric CO2 concentration coupled with its direct, often positive, effect on the growth of plants raises the question of the response of invasive plants to elevated atmospheric CO2 levels. Response of two invasive weeds [purple nutsedge (Cyperus rotundus L.) and yellow nutsedge (Cyperus esculentus L.)] to CO2 enrichment was tested. Plants were exposed to ambient (375 μmol mol−1) or elevated CO2 (ambient + 200 μmol mol−1) for 71 d in open top chambers. Photosynthetic rate did not differ between CO2 treatments for either species. Conductance was lower in purple nutsedge and tended to be lower in yellow nutsedge. Purple nutsedge had higher instantaneous water use efficiency; a similar trend was noted for yellow nutsedge. Purple nutsedge had greater leaf area, root length and numbers of tubers and tended to have more tillers under high CO2 In yellow nutsedge, only tuber number increased under CO2 enrichment. Leaf dry weight was greater for both species when grown under elevated CO2 Only purple nutsedge made seed heads; CO2 level did not change seed head dry weight. Root dry weight increased under the high CO2 treatment for purple nutsedge only, but tuber dry weight increased for both. Total dry weight of both species increased at elevated CO2 Purple nutsedge (under elevated CO2) tended to increase allocation belowground, which led to greater root‐to‐shoot ratio (R:S); R:S of yellow nutsedge was unaffected by CO2 enrichment. Findings suggest both species, purple more than yellow nutsedge, may be more invasive in a future high‐CO2 world.
Mitigation Assessment of Vegetated Drainage Ditches for Collecting Irrigation Runoff in California
Authors: Moore M.T. , Denton D.L. , Cooper C.M. , Wrysinski J. , Miller J.L. , Reece K. , Crane D. , Robins P. 
Published: February 2008

AbstractWidespread contamination of California water bodies by the organophosphate insecticides diazinon and chlorpyrifos is well documented. While their usage has decreased over the last few years, a concomitant increase in pyrethroid usage (e.g., permethrin) (replacement insecticides) has occurred. Vegetated agricultural drainage ditches (VADD) have been proposed as a potential economical and environmentally efficient management practice to mitigate the effects of pesticides in irrigation and storm runoff. Three ditches were constructed in Yolo County, California for a field trial. A U‐shaped vegetated ditch, a V‐shaped vegetated ditch, and a V‐shaped unvegetated ditch were each amended for 8 h with a mixture of diazinon, permethrin, and suspended sediment simulating an irrigation runoff event. Water, sediment, and plant samples were collected spatially and temporally and analyzed for diazinon and permethrin concentrations. Pesticide half‐lives were similar between ditches and pesticides, ranging from 2.4 to 6.4 h. Differences in half‐distances (distance required to reduce initial pesticide concentration by 50%) among pesticides and ditches were present, indicating importance of vegetation in mitigation. Cis‐permethrin half‐distances in V ditches ranged from 22 m (V‐vegetated) to 50 m (V‐unvegetated). Half‐distances for trans‐permethrin were similar, ranging from 21 m (V‐vegetated) to 55 m (V‐unvegetated). Diazinon half‐distances demonstrated the greatest differences (55 m for V‐vegetated and 158 m for V‐unvegetated). Such economical and environmentally successful management practices will offer farmers, ranchers, and landowners a viable alternative to more conventional (and sometimes expensive) practices.
The Use of Ion Exchange Membranes for Isotope Analyses on Soil Water Sulfate: Laboratory Experiments
Authors: Kwon Jang‐Soon , Mayer Bernhard , Yun Seong‐Taek , Nightingale Michael 
Published: February 2008

AbstractTo investigate the potential use of anion exchange membranes (plant root simulator [PRS] probes) for isotope investigations of the soil sulfur cycle, laboratory experiments were performed to examine the sulfate exchange characteristics and to determine the extent of sulfur and oxygen isotope fractionation during sulfate sorption and desorption on the probes in aqueous solutions and simulated soil solutions. The sulfate‐exchange tests in aqueous solutions under varying experimental conditions indicated that the amount of sulfate exchanged onto PRS probes increased with increasing reaction time, initial sulfate concentration, and the number of probes used (= surface area), whereas the percentage of removal of available sulfate was constant irrespective of the initial sulfate concentration. The competition of nitrate and chloride in the solution lowered the amount of exchanged sulfate. The exchange experiments in a simulated soil under water‐saturated and water‐unsaturated conditions showed that a considerable proportion of the soil sulfate was exchanged by the PRS probes after about 10 d. There was no evidence for significant sulfur and oxygen isotope fractionation between soil sulfate and sulfate recovered from the PRS probes. Therefore, we recommend the use of PRS probes as an efficient and easy way to collect soil water sulfate for determination of its isotope composition.
Effects of Ionic Strength, Temperature, and pH on Degradation of Selected Antibiotics
Authors: Loftin Keith A. , Adams Craig D. , Meyer Michael T. , Surampalli Rao 
Published: February 2008

AbstractAqueous degradation rates, which include hydrolysis and epimerization, for chlortetracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin A (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na2HPO4), temperature (7, 22, and 35°C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (α = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significantly (α = 0.05). Degradation also was observed for TYL at pH 2 and 11. No significant degradation was observed for LNC, SCP, SDM, STZ, TRM, and TYL (pH 5, 7, and 9) under study conditions. Pseudo first‐order rate constants, half‐lives, and Arrhenius coefficients were calculated where appropriate. In general, hydrolysis rates for CTC, OTC, and TET increased as pH and temperature increased following Arrhenius relationships. Known degradation products were used to confirm that degradation had occurred, but these products were not quantified. Half‐lives ranged from less than 6 h up to 9.7 wk for the tetracyclines and for TYL (pH 2 and 11), but no degradation of LIN, the sulfonamides, or TRM was observed during the study period. These results indicate that tetracyclines and TYL at pH 2 and 11 are prone to pH‐mediated transformation and hydrolysis in some cases, but not the sulfonamides, LIN nor TRM are inclined to degrade under study conditions. This indicates that with the exception of CTC, OTC, and TET, pH‐mediated reactions such as hydrolysis and epimerization are not likely removal mechanisms in surface water, anaerobic swine lagoons, wastewater, and ground water.
Effect of Nitrogen Fertilizer Application on Growing Season Soil Carbon Dioxide Emission in a Corn–Soybean Rotation
Authors: Al‐Kaisi Mahdi M. , Kruse Marc L. , Sawyer John E. 
Published: February 2008

AbstractNitrogen application can have a significant effect on soil carbon (C) pools, plant biomass production, and microbial biomass C processing. The focus of this study was to investigate the short‐term effect of N fertilization on soil CO2emission and microbial biomass C. The study was conducted from 2001 to 2003 at four field sites in Iowa representing major soil associations and with a corn (Zea maysL.)–soybean (Glycine maxL. Merr.) rotation. The experimental design was a randomized complete block with four replications of four N rates (0, 90, 180, and 225 kg ha−1). In the corn year, season‐long cumulative soil CO2emission was greatest with the zero N application. There was no effect of N applied in the prior year on CO2emission in the soybean year, except at one of three sites, where greater applied N decreased CO2emission. Soil microbial biomass C (MBC) and net mineralization in soil collected during the corn year was not significantly increased with increase in N rate in two out of three sites. At all sites, soil CO2emission from aerobically incubated soil showed a more consistent declining trend with increase in N rate than found in the field. Nitrogen fertilization of corn reduced the soil CO2emission rate and seasonal cumulative loss in two out of three sites, and increased MBC at only one site with the highest N rate. Nitrogen application resulted in a reduction of both emission rate and season‐long cumulative emission of CO2–C from soil.