bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Procedure to Obtain Well-Mixed Soil Binder Samples of Medium Stiff to Stiff Expansive Clayey Soil for Deep Soil Mixing Simulation
Authors: Bhadriraju Venkat , Puppala Anand J. , Madhyannapu Raja Sekhar , Williammee Richard 
Published: December 2007

Abstract
This paper presents a laboratory procedure to prepare well-mixed soil binder samples for simulation of deep soil mixing to stabilize medium stiff to stiff expansive clayey soils. Two natural clays were selected, and stabilized with lime, cement, and combinations of both at various proportions and dosages. Results obtained from tests conducted on identical specimens showed that the current soil-binder mixing and specimen preparation procedures have yielded homogenous and uniform treated clayey specimens. Engineering properties measured on the treated soil specimens were analyzed and ranked to arrive at the optimum binder dosages for field implementation. Concurrent mineralogical studies on selected specimens using X-ray diffraction and scanning electron micrograph studies revealed the presence of pozzalonic compounds and interwoven threads in the treated samples indicative of the mixing and stabilizing phenomenon. The recommended chemical dosages were later implemented in a field deep mixing study to construct two test pads. Several in situ wet grab samples were collected from the treated ground and were subjected to strength and stiffness tests in the laboratory. Comparisons between test results from field cores and laboratory fabricated specimens showed a good match suggesting that the formulated test protocol has provided a reasonable simulation of the DM process.
Toe-Driven Tapered Fiber-Reinforced Polymer Self-Consolidating Concrete Composite Piles: New High-Performance Technology for Deep Foundations
Authors: Nehdi M. , Sakr M. , El Naggar M.-H. 
Published: December 2007

Abstract
Field experience shows that it has been often difficult to assure the structural integrity and uniformity of the cross-sectional area of cast-in-place concrete piles since cavities and soil pockets tend to form due to the lack of visibility and accessibility during construction. Moreover, corrosion in pre-stressed concrete, reinforced concrete, and steel shell piles has been very costly, exceeding $2 billion of annual repairs in the United States alone. This paper summarizes the findings of a comprehensive research program that was undertaken to develop novel technology that addresses both construction and durability related problems of piles. A new toe-driving technique was developed to install empty fiber-reinforced polymer (FRP) shells into dense soils. A specially developed cost-effective self-consolidating concrete (SCC), a material that flows under gravity and assures the integrity of piles is subsequently cast into the FRP tubes, which provide corrosion-resistant reinforcement. Driving tests were carried out on large-scale model FRP-SCC and steel piles installed in dense dry sand enclosed in a pressure chamber using the new technique along with conventional hammering at the pile head. FRP-sand interface characteristics were evaluated. The pile specimens were instrumented to investigate their dynamic behavior during driving, and their response to static compressive, uplift, and lateral loading. Both cylindrical and tapered FRP-SCC piles were tested. It is shown that the new toe-driving technique is very suitable for installing FRP and other thin-walled piles in dense soils. Results from dynamic pile driving and static load tests indicate that FRP-SCC composite piles are a very competitive and attractive option for deep foundation applications.
Effect of Irradiation Damage on the Deformation Properties of Zr-2.5Nb Pressure Tubes
Authors: Griffiths M. , Wang N. , Buyers A. , Donohue S. A. 
Published: December 2007

Abstract
The diametral expansion, elongation, and sag rates of Zr-2.5Nb pressure tubes in CANDU® (CANada Deuterium Uranium) nuclear reactors are important properties that limit their useful life and the maximum power level for reactor operation. As a result irradiation creep models are needed to predict the deformation behavior of the core components over the reactor life. It is important to know the creep behavior as a function of neutron flux in order to develop creep models over the range of operating conditions in the reactor core. At the edge of the reactor core, the neutron flux is decreasing very rapidly and there is a complex transition in creep behavior from irradiation-dominated creep to thermal-dominated creep. Also, mechanical properties such as tensile strength, fracture toughness, and delayed hydride-cracking are changing in the transition from thermal to irradiation conditions at the edge of the reactor core.
Detailed studies have been completed on a Zr-2.5Nb tube irradiated in the NRU materials test reactor at Chalk River Laboratories. Pressure tube 601 was operating for a period of 66 950 h at temperatures ranging from about 547 K at the inlet and 571 K at the outlet. After the tube was removed in 1988 samples were taken for retrospective dosimetry to determine the fast neutron flux along the assembly. It was determined that the tube had been irradiated to a peak fluence of about 6×1025 n⋅m−2 corresponding to a fast neutron flux of about 2×1017 n⋅m−2⋅s−1. The flux profile was mapped and it was clear that the flux dropped rapidly to negligible values at about 0.5 m from the ends of the fueled zone. Samples of pressure tubes were taken for hardness testing and characterization by TEM and XRD analysis at various locations corresponding with different operating conditions (neutron flux and temperature) but at the same time. The creep behavior during operation was obtained by periodic gaging of the pressure tube internal diameter.
The results of the microstructure characterization are presented and discussed in relation to the measured mechanical properties (creep and hardness). The microstructure and mechanical properties change significantly in the transition from the unirradiated state up to fluxes of about 1×1017 n⋅m−2⋅s−1.
Deformation Anisotropy of Annealed Zircaloy-2 as a Function of Fast Neutron Fluence
Authors: Wei X. , Theaker J. R. , Griffiths M. 
Published: December 2007

Abstract
For unirradiated Zircaloys, plastic deformation occurs mostly by ⟨a⟩-type dislocation glide on prismatic planes. The critical resolved shear stress of the prismatic slip system is lower than that of the other deformation systems (⟨a⟩ slip on basal planes, and ⟨a⟩ or ⟨c+a⟩ slip on pyramidal planes, and twinning). This means that the yield strength (and ultimate tensile strength) for directions with a strong basal pole texture is higher than directions with a strong prism pole texture. Irradiation increases the yield stress on all slip planes due to the formation of dislocation loops that act as barriers to slip. Experimental evidence from Zircaloy-2 samples irradiated at 70°C suggests that the increase in critical resolved yield stress due to irradiation is lower for basal compared with prism planes.
Teaching Hanford History in the Classroom and in the Field
Authors: BAUMAN ROBERT 
Published: December 2007

Abstract
This article explores the opportunities and challenges of using public history to teach the history of a controversial site like the Hanford Nuclear Reservation to undergraduate students. The Hanford site is often either celebrated as a place of heroic, scientific pioneers or denigrated as a disgraceful atomic wasteland. The author of the article demonstrates that incorporating public historians into his courses has provided students with broadened and more nuanced understandings of the representations and interpretations of Hanford's often contested past and present. The essay also suggests additional benefits to introducing undergraduate students to public history.
A tápcsatorna (gyomor, vékonybél, vastagbél) másodlagos daganatainak sebészeter
Authors: Góbor László , Czeyda-Pommersheim Ferenc , Köves István 
Published: December 2007

AbsztraktA tápcsatornában jelentkező áttét az alapbetegség disseminatióját jelzi, ilyenkor alapvetően palliatív célú beavatkozás jön szóba. Ebben a lokalizációban jelentkező áttétek előfordulása ritka, kimutatásuk idején a tumoros folyamat előrehaladottnak tekintendő, általában radikális sebészeti beavatkozásra nincs lehetőség, és ezért a disseminált tumorokra vonatkozó szabályok érvényesek. Műtétet végezhetünk vitális indikációval vérzés, perforatio, ileus esetén. A metastasisok radikális eltávolítása javíthatja a túlélést, ilyenkor R0 resectióra törekszünk. Ha a beteg klinikailag daganatmentessé tehető, neoadjuváns vagy adjuváns kezelés mellett a primer tumor viselkedését is figyelembe vevő műtétet végezhetünk. Osztályunkon 2000. január 1. és 2005. december 31. között 1053 gastrointestinalis lokalizációjú tumor miatt végeztünk műtéteket. Összesen 24 esetben igazolódott szekunder folyamat: 11 gyomor-, 9 vékonybél-, 4 vastagbéldaganat bizonyult áttétnek. Munkánkban a fellelt közleményeket tekintjük át, és saját tapasztalatainkat foglaljuk össze.
Effect of sediment particle size on polycyclic aromatic hydrocarbon biodegradation: Importance of the sediment–water interface
Authors: Xia Xinghui , Wang Ran 
Published: December 2007

Abstract
Mechanisms for the effects of sediment on the biodegradation of organic compounds in the aquatic environment are not clear. In this research, effects of sediment characteristics on biodegradation kinetics of chrysene and benzo[a]pyrene were studied by inoculating polycyclic aromatic hydrocarbon (PAH)–degrading bacteria. Because water and PAHs can pass a polytet-rafluoroethylene membrane yet bacteria and sediment cannot, a membrane experiment was performed to compare the biodegradation rates of PAHs in water and at the sediment–water interface, providing direct evidence that the PAH biodegradation rate is enhanced by the presence of sediment. Biodegradation of PAHs in water–sediment systems was fitted to zero-order kinetics; the order of biodegradation rate in water–sediment systems with different sediment was fine silt &gt; clay &gt; coarse silt. Biodegradation of PAHs in water–sediment systems occurred mainly at the sediment–water interface. According to membrane experiment results, when the biodegradation kinetics was fit to a zero-order equation, the maximum specific growth rates of bacteria (1/d) at the sediment–water interface were approximately three- to fourfold those in the water phase. Furthermore, the associated mechanisms regarding the effect of sediment characteristics were analyzed by investigating the process of bacterial growth and the distribution of bacteria and PAHs between water and sediment phases.
Interaction between carbamazepine and humic substances: A fluorescence spectroscopy study
Authors: Bai Yingchen , Wu Fengchang , Liu Congqiang , Guo Jianyang , Fu Pingqing , Li Wen , Xing Baoshan 
Published: December 2007

Abstract
Carbamazepine is a popular drug that has been detected in natural environments, but little is known about its biogeo chemical cycling, influencing factors, and eco-environmental effects in aquatic ecosystems. Interaction between carbamazepine and humic substances, including fulvic and humic acids, was studied using three-dimensional excitation–emission matrix fluorescence spectroscopy and synchronous-scan fluorescence spectroscopy. The intrinsic fluorescence of humic substances was quenched on the addition of carbamazepine, and static quenching was the primary mechanism. The binding parameters on their interaction, including the conditional binding constants (log K) and binding capacities (CL), were estimated by the Ryan-Weber nonlinear theory equation. Log K ranged from 3.41 to 5.04 L/mol at 25°C and pH 7.0. The influence of pH on the complexation and the competition between carbamazepine and Cu(II) for fluorescence-binding sites also were discussed. The present results would be helpful in understanding the fate and biogeochemical cycling of other pharmaceuticals and personal care products in aquatic ecosystems.
Influences of metal-ligand complexes on the cadmium and zinc biokinetics in the marine bacterium, Bacillus firmus
Authors: Keung Chung Fai , Guo Feng , Qian Peiyuan , Wang Wen-Xiong 
Published: December 2007

Abstract
Uptake kinetics of cadmium and zinc in gram-positive bacteria, Bacillus firmus, isolated from Hong Kong sediments were examined in the present study. The metal uptake by the bacteria was measured at different ambient free metal ion concentrations (10−12–10−6 M Cd2+ and 10−10–10−6 M Zn2+) by adding different concentrations of total dissolved Cd and Zn and hydrophilic organic ligands (ethylenedinitrilotetraacetic acid, nitrilotriacetic acid, and citrate). Our data suggest that Cd and Zn uptake by B. firmus is best predicted by Cd2+ and Zn2+ activities. Free metal ions were complexed with the active sites on the bacterial surface, and an equilibrium between the free metal ion and surface-metal complex was reached quickly. After binding, the metal ions were then biologically transported into the bacteria. In addition, with the presence of lipophilic organic ligands (diethyldithiocarbamate and oxine), the lipophilic metal complex was internalized rapidly into B. firmus by passive diffusion through the bacterial plasma membrane. The uptake of the lipophilic metal complex could not be predicted by the free ion activity model because the mass transport through plasma membrane was the most important metal uptake pathway. Furthermore, the efflux of Cd and Zn by B. firmus was determined in the present study. The calculated efflux rate constants of Cd and Zn were (5.55 ± 1.96) × 10−4/min and (3.75 ± 1.04) × 10−4/min, respectively. The present study helps us to understand the process of bioaccumulation of metals in marine bacteria, which remains a poorly studied area.
Methylmercury extraction from artificial sediments by the gut juice of the sipunculan, Sipunculus nudus
Authors: Zhong Huan , Wang Wen-Xiong 
Published: December 2007

Abstract
Artificially prepared sediments were used to investigate their binding with methylmercury (MeHg). The bioavailability of sediment-bound MeHg then was quantified by measuring the extraction by gut juice of the sipunculan Sipunculus nudus, as well as by different free amino acids and bovine serum albumin (BSA). Methylmercury distribution in different molecular weight-size fractions of gut juice also was determined using an ultrafiltration methodology. Organic and clay content were the two most important sediment components in MeHg partitioning, but most of the sediment-bound MeHg was complexed by organic matter (fulvic acid &gt; humic acid) in sediments. Treatment with humic or fulvic acid generally increased the amount of bioavailable MeHg. Cysteine was more important than other amino acids in MeHg extraction. Proteins (especially &gt;100 kDa fraction) in gut juice rather than free amino acids were the main agents in gut juice that extracted MeHg from sediments. Most extracted MeHg from artificial sediments was associated with the &gt;100 kDa fraction (probably proteins) of gut juice but not with organic matter from sediments (humic acid and fulvic acid). Our results suggested that competition among different agents in gut juice (especially the large molecular-weight proteins) and the organic content of the sediments controlled the bioavailability of sediment-bound MeHg.
Organochlorine pesticides in the surface water and sediments of the Pearl River Estuary, South China
Authors: Yu Mei , Luo Xiaojun , Chen Shejun , Mai Bixian , Zeng Eddy Y 
Published: December 2007

Abstract
Samples of surface water, suspended particulate matter (SPM), and surface sediment, collected from the Pear River Estuary, Guangdong Province, China in July of 2002 and April of 2003, were analyzed for hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) using gas chromatography with electron capture detection. The levels of total HCHs in water varied from 213 to 3,116 pg/L, although in sediments they ranged from 181 to 1,388 pg/g dry weight. The levels of DDTs were in the range of 228 to 3,284 pg/L in water and 57 to 2,244 pg/g dry weight in sediments, respectively. The observed spatial and temporal variability of concentrations of the target compounds in water body could be attributed to the differences of SPM contents in water body and organic carbon contents in SPM between the two sampling periods. Seven of the 10 water samples collected in July of 2002 had the ratio of dichlorodiphenyltrichloroethane/(dichlorobischlorophenylethane + dichlorodiphenyldi-chloroethylene) (DDT/[DDD + DDE]) higher than one, indicating that there were likely fresh inputs of DDT to the Pearl River Estuary. The significant positive correlations between the organochlorine pesticide concentrations and organic carbon contents in SPM and sediments indicated that organic matter played an important role in controlling the distributions of these pollutants in the marine environment. Varied correlations between the partition coefficients of pollutants and total organic carbon, salinity, and total SPM contents have been observed, which indicated the influences of these factors on controlling the transport and fate of pollutants in the marine environment.
Toxicological safety assessment of genetically modified Bacillus thuringiensis with additional N-acyl homoserine lactonase gene
Authors: Peng Donghai , Zhou Chenfei , Chen Shouwen , Ruan Lifang , Yu Ziniu , Sun Ming 
Published: December 2007

Abstract
The aim of the present study is to evaluate the toxicology safety to mammals of a genetically modified (GM) Bacillus thuringiensis with an additional N-acyl homoserine lactones gene (aiiA), which possesses insecticidal activity together with restraint of bacterial pathogenicity and is intended for use as a multifunctional biopesticide. Safety assessments included an acute oral toxicity test and 28-d animal feeding study in Wistar rats, primary eye and dermal irritation in Zealand White rabbits, and delayed contact hypersensitivity in guinea pigs. Tests were conducted using spray-dried powder preparation. This GM product showed toxicity neither in oral acute toxicity test nor in 28-d animal feeding test at a dose of 5,000 mg/kg body weight. During the animal feeding test, there were no significant differences in growth, food and water consumption, hematology, blood biochemical indices, organ weights, and histopathology finding between rats in controls and tested groups. Tested animals in primary eye and dermal irritation and delayed contact hypersensitivity test were also devoid of any toxicity compared to controls. All the above results demonstrated that the GM based multifunctional B. thuringiensis has low toxicity and low eye and dermal irritation and would not cause hypersensitivity to laboratory mammals and therefore could be regarded as safe for use as a pesticide.
Influences of 4-nonylphenol ondoublesex- andmab-3–related transcription factor 1 gene expression and vitellogenin mRNA induction of adult rare minnow (Gobiocypris rarus)
Authors: Zhang Xiaoyan , Zha Jinmiao , Wang Zijian 
Published: December 2007

AbstractThe mab-3 of Caenorhabditis elegans and doublesex of Drosophila are two sex-determining genes that are found to have only a common DNA binding motif called a doublesex and mab-3 (DM) domain among phyla. The DM domain regulates some aspects of sexual development such as yolk protein synthesis. In the present study, by using DM degenerate primers' 13 sequences of doublesex and mab-3–related transcription factor (dmrt), genes were cloned from genomic DNA of rare minnow (Gobiocypris rarus) and expression of dmrt1 was detected only in testis of adult males. In addition, partial sequences of vitellogenin (vtg) and β-actin genes as comparative expression of genes were cloned from the female liver by degenerate primers based on conserved regions. The vtg mRNA in male liver was induced significantly in concentrations higher than 2μg/L treatments, although adult rare minnow were exposed to nominal concentrations of 2, 10, 50, 250, and 1,250 μg/L 4-nonylphenol (4-NP) for 21 d. The dmrt1 mRNA level was significantly downregulated in a dose-dependent manner in all exposure groups of males. Moreover, other toxic endpoints, including growth, gonadosomatic index, hepatosomatic index, and histopathology, were determined. However, significant effects were observed only at higher exposure concentrations. Therefore, sex-specific genes such as dmrt1 can be used as a more sensitive biomarker for 4-NP and for discovering molecular mechanisms underlying toxic response.
Determination and fate of oxytetracycline and related compounds in oxytetracycline production wastewater and the receiving river
Authors: Li Dong , Yang Min , Hu Jianying , Ren Liren , Zhang Yu , Li Kuiziao 
Published: December 2007

Abstract
This study investigated the occurrence and fate of oxytetracycline (OTC) and its related substances, 4-epi-oxytetracycline (EOTC), α-apo-oxytetracycline (α-apo-OTC), and β-apo-oxytetracycline (β-apo-OTC), in a wastewater treatment plant (WWTP) treating OTC production wastewater and a river receiving the effluent from the WWTP using liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). The percent removal of OTC in the WWTP was 38.0 ± 10.5%, and the concentration of OTC was still up to 19.5 ± 2.9 mg/L in the treated outflow. The concentration slightly decreased along the river, from 641 ± 118 μg/L at site R2 (discharging point) to 377 ± 142 μg/L at site R4 (∼20 km from site R2), which was still higher than the minimal inhibition concentration of OTC reported (∼250 μg/L). On the other hand, the total amount of its related substances in the treated effluent was less than 5% of OTC. Concentrations of α-apo-OTC and β-apo-OTC increased along the river, from 5.76 ± 0.63 and 2.08 ± 0.30 μg/L at site R2 to 11.9 ± 4.9 and 12.0 ± 4.6 μg/L at R4, respectively, although EOTC decreased from 31.5 ± 3.8 to 12.9 ± 1.1 μg/L, respectively. The mean concentration of β-apo-OTC in river sediments was 20.8 ± 7.8 mg/kg, and its ratio to OTC was approximately 0.11, nearly twice the ratio of α-apo-OTC and EOTC to OTC (0.058 ± 0.014 and 0.061 ± 0.015, respectively).
Resistant desorption of hydrophobic organic contaminants in typical Chinese soils: Implications for long-term fate and soil quality standards
Authors: Yang Weichun , Duan Lin , Zhang Nan , Zhang Chengdong , Shipley Heather J , Kan Amy T , Tomson Mason B , Chen Wei 
Published: December 2007

Abstract
Soil contamination is an enormous problem in China and severely threatens environmental quality and food safety. Establishing realistic soil quality standards is important to the management and remediation of contaminated sites and must be based on thorough understanding of contaminant desorption from soil. In the present study, we evaluated sorption and desorption behaviors of naphthalene, phenanthrene, atrazine, and lindane (four common soil contaminants in China) in two of the most common Chinese soils. The desorption of these compounds exhibited clear biphasic pattern—a fraction of contaminants in soil was much less available to desorption and persisted much longer than what was predicted with the conventional desorption models. The unique thermodynamic characteristics associated with the resistant-desorption fraction likely have important implications for the mechanism(s) controlling resistant desorption. Experimental observations in the present study are consistent with our previous work with chlorinated compounds and different adsorbents and could be well modeled with a biphasic desorption isotherm. We therefore suggest that more accurate biphasic desorption models should be used to replace the conventional linear sorption/desorption model that is still widely adopted worldwide in contaminant fate prediction and soil quality standard calculations.