bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing Parents’ and Children's Views of Children's Quality of Life After Heart Transplant
Authors: Green Angela L. , McSweeney Jean , Ainley Kathy , Bryant Janet
Published: October 2008

PURPOSE.  The purpose of this focused ethnographic study was to explore the quality of life (QOL) of school‐age heart‐transplant recipients.

DESIGN AND METHODS.  Semistructured interviews were conducted with 11 parent–child dyads. Data were analyzed using content analysis and constant comparison.

RESULTS.  Participants identified key factors impacting the children's QOL including: participation in normal activities, normalcy, staying healthy, sources of strength and support, and struggles (parents’ perspectives) and doing what kids do, being with family and friends, and being a heart transplant kid (children's perspectives).

PRACTICE IMPLICATIONS.  Interventions focusing on the key factors identified by participants may impact the QOL of school‐age heart‐transplant recipients.
A Novel, Intensive Home‐Visiting Intervention for Runaway, Sexually Exploited Girls
Authors: Edinburgh Laurel D. , Saewyc Elizabeth M.
Published: October 2008

PURPOSE.  Few studies have examined interventions that help adolescents who run away. This study both describes a home‐visiting intervention program for young, sexually assaulted runaways (10–14 years old) and provides preliminary outcomes from the first 20 female participants.

DESIGN AND METHODS.  Using a strengths‐based approach, advanced practice nurses provided frequent home and school visits and case management, and assisted girls to access an empowerment group over a 1‐year period.

RESULTS.  Teens’ risk behaviors decreased, including truancy, runaway episodes, sexually transmitted infections, and substance use.

CONCLUSIONS.  Preliminary results suggest that this is an effective intervention for reducing risk behaviors and helping younger runaways reconnect to school and family.

PRACTICE IMPLICATIONS.  Client‐centered interventions in community settings can address the complex health needs of vulnerable young runaways.
SSR based linkage and mapping analysis of C, a yellow cocoon gene in the silkworm, Bombyx mori
Authors: Zhao Yun‐Po , Li Mu‐Wang , Xu An‐Ying , Hou Cheng‐Xiang , Li Ming‐Hui , Guo Qiu‐Hong , Huang Yong‐Ping , Guo Xi‐Jie
Published: October 2008

The yellow color of the cocoon of the silkworm Bombyx mori is controlled by three genes, Y (Yellow haemolymph), I (Yellow inhibitor) and C (Outer‐layer yellow cocoon), which are located on linkage groups 2, 9 and 12, respectively. Taking advantage of a lack of crossing over in females, reciprocal backcrossed F1 (BC1) progeny were used for linkage analysis and mapping of the C gene using silkworm strains C108 and KY, which spin white and yellow cocoons, respectively. DNA was extracted from individual pupae and analyzed for simple sequence repeat (SSR) markers. The C gene was found to be linked to seven SSR markers. All the yellow cocoon individuals from a female heterozygous backcross (BC1 F) showed a heterozygous profile for SSR markers on linkage group 12, whereas individuals with light yellow cocoons showed the homozygous profile of the strain C108. Using a reciprocal heterozygous male backcross (BC1 M), we constructed a linkage map of 36.4 cM with the C gene located at the distal end, and the closest SSR marker at a distance of 13.9 cM.
Effects of starvation on the vitellogenesis, ovarian development and fecundity in the ectoparasitoid, Nasonia vitripennis (Hymenoptera: Pteromalidae)
Authors: Dong Sheng‐Zhang , Ye Gong‐Yin , Yao Peng‐Cheng , Huang Yao‐Liang , Chen Xue‐Xin , Shen Zhi‐Cheng , Hu Cui
Published: October 2008

A female‐specific protein, vitellogenin (Vg), and its corresponding egg vitellin (Vt) are identified in the ectoparasitic wasp Nasonia vitripennis. Both native Vt and Vg have a molecular mass of about 350 kDa, which is composed of two subunits of approximately 190 kDa and 165 kDa under reducing and denaturing conditions (sodium dodecyl sulfate—polyacrylamide gel electrophoresis). An indirect sandwich enzyme‐linked immunosorbent assay developed with both monoclonal and polyclonal antibodies against N. vitripennis Vt. Vg was first detected in the hemolymph on the 10th day after parasitism, and was first observed in oocytes on the 12th day. In adults deprived of food, the highest hemolymph Vg level occurred at the time of adult eclosion and the highest level of Vt in ovaries was found at 30 h after eclosion. In contrast, feeding adults with 20% sucrose resulted in the reduction of Vt uptake by ovaries and the extension of life span, but had little effect on Vg production. Deprived of hosts, starvation of female wasps had no significant effects on ovariole growth and oocyte maturation before the wasps died. However, starvation of female wasps supplied with hosts accelerated the wasps laying progeny into hosts, but resulted in a decrease of total progeny production by comparison with wasps fed with 20% sucrose.
The integrated use of chemical insecticides and the entomopathogenic nematode, Steinernema carpocapsae (Nematoda: Steinernematidae), for the control of sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)
Authors: Cuthbertson Andrew G. S. , Mathers James J. , Northing Phil , Prickett Anthony J. , Walters Keith F. A.
Published: October 2008

The integration of chemical insecticides and infective juveniles of the entomopathogenic nematode Steinernema carpocapsae (Wesier) (Nematoda: Steinernematidae), to control second instars of the sweetpotato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) was investigated. Using a sand bioassay, the effects of direct exposure of S. carpocapsae for 24 h to field rate dilutions of four insecticides (spiromesifen, thiacloprid, imidacloprid and pymetrozine) on infectivity to Galleria mellonella larvae were tested. Although all chemicals tested, except spiromesifen, produced acceptable nematode infectivity rates, they were all significantly less than the water control. The effect of insecticide treatment (dry residues of spiromesifen, thiacloprid and pymetrozine and soil drench of imidacloprid) on the efficacy of the nematode against B. tabaci was also investigated. Nematodes in combination with thiacloprid and spiromesifen gave higher B. tabaci mortality (86.5% and 94.3% respectively) compared to using nematodes alone (75.2%) on tomato plants. There was no significant difference in B. tabaci mortality when using the chemicals imidacloprid, pymetrozine and spiromesifen in conjunction with nematodes compared to using the chemicals alone. However, using thiacloprid in combination with the nematodes produced significantly higher B. tabaci mortality than using the chemical alone. The integration of S. carpocapsae and these chemical agents into current integrated pest management programmes for the control of B. tabaci is discussed.
Influence of light and habitat on predation of Culex quinquefasciatus (Diptera: Culicidae) larvae by the waterbugs (Hemiptera: Heteroptera)
Authors: Sana Nabaneeta , Aditya Gautam , Bal Animesh , Saha Goutam K.
Published: October 2008

The influence of light and habitat structure on the predation of Culex quinquefasciatus larvae by the common heteropteran water bug, Diplonychus (=Sphaerodema) annulatus, D. rusticus and Anisops bouvieri was assessed in the laboratory. It was revealed that water bugs predate more in presence of light than in dark conditions. While A. bouvieri consumed more prey in structured conditions, D. annulatus and D. rusticus consumed more prey in open conditions. The selection of prey size as well as the respective numbers varied between predators and treatments significantly. Prey vulnerability (PV), an indicator of predatory efficiency, was highest for D. annulatus, moderate for D. rusticus and low for A. bouvieri. Prey consumption and PV values under different treatment conditions indicate that for belostomatid water bugs D. annulatus and D. rusticus, the order of prey consumption under different habitat and light/dark combinations is light open > dark open > light vegetated > dark vegetated. In the case of the backswimmer, A. bouvieri, the order of prey consumption appeared to be light structured > dark structured > light open > dark open. These findings were consistent with resource‐partitioning by water bug species sharing the same guild. If the observed results are extended to natural settings the efficiency of these predators in controlling mosquito populations will vary with the structural complexity of habitats and the intensity of light.
Phylogenetic analyses of some genera in Oedipodidae (Orthoptera: Acridoidea) based on 16S mitochondrial partial gene sequences
Authors: Yin Xiang‐Chu , Li Xin‐Jiang , Wang Wen‐Qiang , Yin Hong , Cao Cheng‐Quan , Ye Bao‐Hua , Yin Zhan
Published: October 2008

Based on the 16S mitochondrial partial gene sequences of 29 genera, containing 26 from Oedipodidae and one each from Tanaoceridae, Pyrgomorphidae and Tetrigidae (as outgroups), the homologus sequences were compared and phylogenetic analyses were performed. A phylogenetic tree was inferred by neighbor‐joining (NJ). The results of sequences compared show that: (i) in a total of 574 bp of Oedipodidae, the number of substituted nucleotides was 265 bp and the average percentages of T, C, A and G were 38.3 %, 11.4%, 31.8% and 18.5%, respectively, and the content of A+T (70.1%) was distinctly richer than that of C+G (29.9%); and (ii) the average nucleotide divergence of 16S rDNA sequences among genera of Oedipodidae were 9.0%, among families of Acridoidea were 17.0%, and between superfamilies (Tetrigoidea and Acridoidea) were 23.9%, respectively. The phylogenetic tree indicated: (i) the Oedipodidae was a monophyletic group, which suggested that the taxonomic status of this family was confirmed; (ii) the genus Heteropternis separated from the other Oedipodids first and had another unique sound‐producing structure in morphology, which is the type‐genus of subfamily Heteropterninae; and (iii) the relative intergeneric relationship within the same continent was closer than that of different continents, and between the Eurasian genera and the African genera, was closer than that between Eurasians and Americans.
Early intravitreal bevacizumab for non‐ischaemic central retinal vein occlusion
Authors: Rensch Florian , Jonas Jost B. , Spandau Ulrich H. M.
Published: October 2008

Purpose:  To evaluate the effect of early intravitreal bevacizumab injections for the treatment of macular oedema caused by non‐ischaemic central retinal vein occlusion (CRVO).

Methods:  The study included 25 patients (25 eyes) with macular oedema caused by non‐ischaemic central retinal vein occlusion, who received three intravitreal injections of 1.5 mg bevacizumab with an interval of 6 weeks between the injections. Mean duration of central retinal vein occlusion prior to the first injection was 4.2 ± 3.6 days. All patients were re‐examined 1, 3 and 6 months after the first injection. The main outcome parameters were visual acuity and macular thickness, as measured by optical coherence tomography.

Results:  Mean visual acuity improved significantly from 0.97 ± 0.40 logMAR at baseline to 0.70 ± 0.42 logMAR (P = 0.007) at 1 month, 0.69 ± 0.46 (P = 0.006) 3 months and 0.69 ± 0.52 (P = 0.015) 6 months after the first injection. Mean central retinal thickness decreased significantly from 530 ± 152 μm at baseline to 347 ± 127 μm (P < 0.001) at 1 month, 370 ± 165 μm (P < 0.001) 3 months and 346 ± 129 μm (P < 0.001) 6 months (P < 0.001) after the first injection. The increase in visual acuity correlated significantly (P < 0.01) with the decrease in macular thickness. Mean intraocular pressure was 14.2 ± 3.2 mmHg at baseline and did not differ significantly from the measurement obtained at 1 month (P = 0.59), 3 months (P = 0.88) and 6 months after the first injection (P = 0.65).

Conclusion:  Intravitreal bevacizumab injections given shortly after onset of non‐ischaemic central retinal vein occlusion may result in a significant increase in vision and a corresponding decrease in macular oedema.
Three‐dimensional angiographic imaging of leakage in branch retinal vein occlusion
Authors: Schmidt‐Erfurth Ursula Margarethe , Stock Geraldine , Pruente Christian , Ahlers Christian
Published: October 2008

Purpose:  Optical coherence tomography (OCT) is used to image branch retinal vein occlusion (BRVO) but lacks information about leakage dynamics and perfusion status. Topographical angiography (TAG) is capable of providing this information and has been described previously in age‐related macular degeneration. This study evaluates TAG in BRVO.

Methods:  We included 56 eyes of 40 consecutive patients with BRVO and a reduction in central vision. Two groups were established based on whether argon laser coagulation was performed or not. A standardized follow‐up was performed. The chorioretinal fluorescence pattern was reconstructed following TAG. Quantitative measurements were also performed.

Results:  TAG performed from indocyanine green angiography (ICGA) showed smaller lesion size (LS) compared to fluorescein angiography (FA) (mean difference: early phase = −1.6 mm2, late phase = −1.8 mm2). The extent of mean LS from early to late phase increased by 0.8 mm2 in FA and by 0.6 mm2 in ICGA. TAG could visualize different degrees of leakage topographically.

Conclusion:  TAG gives new insights into the pathophysiology of BRVO: it enables the visualization of dynamics of leakage and the demonstration of the effects of intravasal stasis. Furthermore, TAG is less impaired by masking phenomena than FA. Functional retinal imaging shows distinct advantages over OCT: quantification of leakage activity is possible using TAG.
Evaluation of Thermal Stress Ratchet in Plastic FEA
Authors: Yamamoto Yukinori , Yamashita Norimichi , Tanaka Masaaki
Published: October 2008

Alternative stress evaluation criteria suitable for Finite Element Analysis (FEA) proposed by Okamoto et al. [1] have been studied by the Committee on Three Dimensional Finite Element Stress Evaluation (C-TDF) in Japan. Thermal stress ratchet criteria in plastic FEA are now under consideration. Two criteria are proposed: evaluating variations in plastic strain increments and evaluating variations in the width of elastic core. To verify the validity of these criteria, calculations were performed for several typical models in C-TDF [2]. This paper shows the results of a simple cylinder model. Cyclic plastic analyses were performed applying sustained internal pressure and alternating linear temperature distribution through the wall. Analyses were performed with various load ranges to evaluate the precise ratchet limit and its behavior across the limit. Both pressure and thermal stress were given parameters. In the analyses, Elastic-Perfectly-Plastic (EPP) material was used and also strain hardening material for comparison. The ratchet limit in the Code [3] is based on Miller’s theoretical analysis [4] for a cylinder assuming a uni-axial stress state, whereas real vessels are in multi-axial stress state. By our calculations, we also examined the ratchet limit in real vessels. The results show that for the cylinder in a multi-axial stress state, the ratchet limit rises 1.2 times the ratchet limit by the Code. The evaluation results show that variations in equivalent plastic strain increments can be used for ratchet criterion and ratcheting can be assessed by confirming the presence of elastic core in the second cycle.
The European Approach to Design by Analysis
Authors: Zeman Josef L.
Published: October 2008

This paper discusses the background of a new approach to check the admissibility of pressure vessels via the Direct Route (DR) to Design by Analysis (DBA), and the various design checks required, in general and in detail. Emphasis is on the various tools and procedures used in applications, and on typical applications.
Evaluation of Fatigue Damage in LWR Water With and Without Threshold and Moderation Factor
Authors: Higuchi Makoto , Tsutsumi Kazuya , Sakaguchi Katsumi
Published: October 2008

During the past twenty years, the fatigue initiation life of LWR structural materials, carbon, low alloy and stainless steels has been shown to decrease remarkably in the simulated LWR (light water reactor) coolant environments. Several models for evaluating the effects of environment on fatigue life reduction have been developed based on published environmental fatigue data. Initially, based on Japanese fatigue data, Higuchi and Iida proposed a model for evaluating such effects quantitatively for carbon and low alloy steels in 1991. Thereafter, Chopra et al. proposed other models for carbon, low alloy and stainless steels by adding American fatigue data in 1993. Mehta developed a new model which features the threshold concept and moderation factor in Chopra’s model in 1995. All these models have undergone various revisions. In Japan, the MITI (Ministry of International Trade and Industry) guideline on environmental fatigue life reduction for carbon, low alloy and stainless steels was issued in September 2000, for evaluating of aged light water reactor power plants. The MITI guideline provide equations for calculations applicable only to stainless steel in PWR water and consequently Higuchi et al. proposed in 2002 a revised model for stainless steel which incorporates new equations for evaluation of environmental fatigue reduction in BWR water. The paper compares the latest versions of these models and discusses the conservativeness of the models by comparison of the models with available test data.
Modeling of Sleeved Taylor Impact Specimens
Authors: Rule William Keith
Published: October 2008

Recently experimental studies have been conducted using a novel form of the Taylor impact test consisting of sleeved cylinders. A soft material of known properties (OFHC Cu) was used for the core and the tight fitting sleeve was fabricated from the material of interest (AF1410 steel). On impact the mushrooming and sliding core places the sleeve in a stress state not normally found in Taylor impact testing. This paper describes a study conducted to evaluate the feasibility of backing out Johnson-Cook strength model coefficients from measured (post-test) deformed geometries of sleeved specimens using an explicit impact code (EPIC). In addition, modifications to the sleeved concept geometry (tapered and capped core) are also explored numerically as well as the sleeve/core sliding friction coefficient.
Fatigue Strength Curves of Thick Walled Tubes Under Consideration of Autofrettage
Authors: Po¨lzl Manfred , Schedelmaier Johannes
Published: October 2008

The continuous increase of production capacity in the high pressure LDPE industry requires a bigger plant size and leads to a permanent improvement of material properties. Due to detailed investigations of metallurgical aspects higher strength and consequently lower wall thickness can be achieved. The result is lower weight respectively less costs for the high pressure equipment. Under operating conditions the high pressure components have to withstand high cyclic load at increased temperature. The design and calculation of high pressure components have an essential impact on equipment reliability and safety in the plant.
Micro-Structural Monitoring of 2.25Cr-1Mo Steel by Surface SH Wave
Authors: Park Ik-Keun , Cho Youn-Ho
Published: October 2008

The feasibility of SH (shear horizontal) waves for monitoring thermally degraded materials is explored. It turns out that the use of SH waves leads to a promising nondestructive technique for the purpose of microstructure evaluation and material characterization of such materials. This is because SH modes can interact with entire surface and subsurface area of specimen that is mainly exposed to severe thermal environment, while a conventional point-by-point technique is confined to just local investigations, underneath a transducer. Consequently, SH modes’ data can show a better sensitivity and provide us with various features for thermal damage evaluation, compared to ones of local inspection, which results in the enhancement of experimental reliability. 2.25Cr-1Mo steel specimens for various degradation levels were prepared by isothermal aging heat treatment at 650° and evaluated by the present technique to investigate the influence of thermal damage to the SH wave feature based on the attenuation coefficients. Discussed is monitoring for thermally degraded structural materials used at high temperature by the surface SH-wave propagating along near surface and subsurface layer with horizontal displacement polarization. Because of the carbide precipitation increase and spheroidization near the grain boundary of a microstructure to aging degradation, the attenuation coefficient had a tendency to increase as degradation proceeded. It was identified possibly to evaluate degradation using the characteristics of the attenuation coefficient and amplitude spectra through Fast Fourier Transform (FFT) analysis. Frequency dependence of the ultrasonic attenuation coefficient to aging degradation appeared large, which made sure that the attenuation coefficient can be an important parameter for the evaluation of aging.
Control Architecture for 30MHz Linear Imaging Array
Authors: Tutwiler R. L. , Stitt J. P. , Shung K. K. , Wu Q. , Ritter T. A. , Yang X. , Sabarad J.
Published: October 2008

The purpose of this system is to have the capability to characterize the performance of very high frequency transducers and arrays. The analog front end is computer controlled by a set of de-multiplexers and multiplexers. The output of the multiplexer network is connected to a TGC array, which is interfaced to a high-speed data acquisition system. A software GUI (Graphical User Interface) has been designed to accomplish this task [1]. A programmable digital I/O interface allows collection of RF channel data and has the capability to be interfaced to a very high frequency analog beam-former under construction. The system front-end electronics (pulsers, receivers, T/R switches, multiplexers, and demultiplexers) have been characterized [2, 3]. The digital I/O signal interface has been integrated and tested. The hardware front end has been integrated to the array interface distribution panel. The individual transducer elements impulse responses have been evaluated and the performance of the array has been tested with a wire test phantom to characterize lateral and axial resolution.
Bolt Load Changes Due to Internal Pressure in Gasketed Flange Connections
Authors: Nagata Satoshi , Matsumoto Mitsuhiro , Sawa Toshiyuki
Published: October 2008

Bolt load changes due to internal pressure are very important in order to evaluate the integrity of gasketed flange connections in the sealing performance point of view, because its gasket stress which dominates leak rate changes according to the bolt load changes. For establishing a connection possesses high reliability and sufficient integrity, it is necessary to clarify the mechanics ofgasketed flange connections. For this purpose, authors carried out experimental pressurizing tests for 3B and 20B gasketed flange connections clamped by various bolt preloads and measured the bolt load changes with increasing internal pressure up to 5MPa. Also a load factor, which is defined as the ratio of axial bolt force increment to pressure thrust force, was calculated using the test results. The test results indicate that 3B and 20B flange connections with the spiral wound gaskets have a constant load factors under sufficient initial clamping forces in assemble.
Effect of Creep-Relaxation Characteristics of Gaskets on the Bolt Loads of Gasketed Joints
Authors: Kobayashi Takashi , Nishida Takahito , Yamanaka Yuki
Published: October 2008

It is known that the bolt loads of gasketed flanged joints decrease in some degree after the assembly due to the creep-relaxation characteristics of gasket. If the bolt loads are greatly reduced, the emission from flanged joints may increase and serious accidents shall occur if things come to the worst. The effect of the creep-relaxation characteristics on the bolt loads of gasketed flanged joints must be clarified. A gasketed bolted joint, in which two hollow cylinders and a gasket is tightened by a set of nut and bolt, is used to clarify the effects of the creep-relaxation characteristics of gaskets on the reduction of bolt loads in this paper. We tried to clarify the phenomena and necessary modeling and experiments were carried out. It is pointed out that the reduction of bolt load cannot be overlooked when stiffer bolts are used in gasketed joints.
Consideration on the Representations of Sealing Behavior of Gaskets: Effects of the Internal Pressure and the Gasket Width
Authors: Kobayashi Takashi , Nishida Takahito , Yamanaka Yuki
Published: October 2008

With the recent increase of a safety and environmental concern, it is important to estimate the leak rate of gasketed flanged connections in piping system. In order to estimate the leak rate, the sealing behavior of a gasket must be known. Currently, evaluation methods of the sealing behavior are proposed in the North America and Europe independently. However, the effects of the internal pressure and the gasket width are not sufficiently considered in both the methods. We have already proposed an evaluation method of sealing behavior based on the gasket strain in a mathematical form, in which the internal pressure and the gasket width are considered. In this paper, the effects of the internal pressure and the gasket width on the leak rate are discussed by applying the evaluation method to ASME and JIS flanges. Comparing the estimated results with those of PVRC and CEN methods, problems are pointed out.
Effect of Shallow Flaws and Biaxial Loading on Transition Temperatures Using a Weibull Stress Model
Authors: Yin Shengjun , Bass Richard , Williams Paul , Ludwig Michael , Keim Elisabeth
Published: October 2008

The aim of the VOCALIST analytical work of the European Commission Project VOCALIST [1] is to analyze the different constraint conditions of tested specimens and to develop a method to describe and predict the constraint dependent shift of the transition temperature T0 for the analyzed specimens. This document describes the analytical work performed within VOCALIST for the biaxial loaded cruciform bend specimens at Oak Ridge National Laboratory (ORNL) USA and FRAMATOME-ANP (FANP) Germany.
Advanced Nondestructive Examination Technologies for Alloy 600 Components
Authors: Adamonis Donald C. , Vestovich Robert P. , Whytsell Fred G. , D’Annucci Filippo , Loehlein Eric , Spain Les , Devlin Russel S. , Kirby Mark W. , Lareau John P. , Sjoberg Per
Published: October 2008

Several pressurized water reactors have experienced primary coolant leaks as a result of degradation in the tubes and J-groove welds of reactor vessel head penetrations. Leakage has been attributed to primary water stress corrosion cracking (PWSCC) of the Alloy 600 nozzle material and Alloy 182/82 weld materials. More recently, other Alloy 600 components including reactor vessel bottom mounted instrumentation nozzles, dissimilar metal pipe welds, hot leg instrument penetrations, and pressurizer heater sleeves have exhibited degradation. Westinghouse has been actively involved in the development of a comprehensive Alloy 600 degradation management program including investigation of root cause, establishing a safety position, and developing inspection and repair/replacement strategies to address Alloy 600 degradation issues. Personnel from Germany, Sweden and the United States have cooperatively developed equipment and nondestructive examination technologies for identification and characterization of degradation that might exist in these Alloy 600 components and attachment welds. These developments represent significant enhancements to technologies and equipment previously available in the industry and are driven by the need to meet new inspection applications and industry requirements which have continued to evolve over the last several years. This paper describes the inspection capabilities available to support Alloy 600 degradation management programs, field experience with those inspection technologies, and the status of ongoing NDE development efforts to enhance future Alloy 600 inspection programs.
Review of Test Methods for Evaluating Hydrogen Embrittlement Susceptibility of Materials
Authors: Burwell Deanna J. , Brongers Michiel P. H. , Beavers John A.
Published: October 2008

For several decades, engineers and technicians responsible for safe transport and storage of hydrogen, in both the government and industry sectors, have had to contend with the problem of hydrogen embrittlement. Today, the problem of hydrogen embrittlement must be considered anew with the systems and environments emerging with the developing hydrogen fuel cell industry. This paper discusses several methods to test for the susceptibility of metallic materials to hydrogen embrittlement. The objective of this review is to assist engineers and designers in selecting hydrogen embrittlement test methods to simulate actual manufacturing and/or operating conditions while using appropriate specimen geometries. Reviewed are standard test methods from American Society for Testing and Materials (ASTM) International, British Aerospace Series (BSEN), and General Motors Engineering sources. These include constant load, rising step load, slow strain rate, inclined wedge, bend, disk pressure, and cantilever beam test methods. Information is provided on load and displacement characteristics, uses, a brief description, and required equipment for each test.
Structure and Molecular Mechanism of a Nucleobase–Cation–Symport-1 Family Transporter
Authors: Weyand Simone , Shimamura Tatsuro , Yajima Shunsuke , Suzuki Shun'ichi , Mirza Osman , Krusong Kuakarun , Carpenter Elisabeth P. , Rutherford Nicholas G. , Hadden Jonathan M. , O'Reilly John , Ma Pikyee , Saidijam Massoud , Patching Simon G. , Hope Ryan J. , Norbertczak Halina T. , Roach Peter C. J. , Iwata So , Henderson Peter J. F. , Cameron Alexander D.
Published: October 2008

The nucleobase–cation–symport-1 (NCS1) transporters are essential components of salvage pathways for nucleobases and related metabolites. Here, we report the 2.85-angstrom resolution structure of the NCS1 benzyl-hydantoin transporter, Mhp1, from
Microbacterium liquefaciens.
Mhp1 contains 12 transmembrane helices, 10 of which are arranged in two inverted repeats of five helices. The structures of the outward-facing open and substrate-bound occluded conformations were solved, showing how the outward-facing cavity closes upon binding of substrate. Comparisons with the leucine transporter LeuT
Aa
and the galactose transporter vSGLT reveal that the outward- and inward-facing cavities are symmetrically arranged on opposite sides of the membrane. The reciprocal opening and closing of these cavities is synchronized by the inverted repeat helices 3 and 8, providing the structural basis of the alternating access model for membrane transport.
Observation of Pulsed γ-Rays Above 25 GeV from the Crab Pulsar with MAGIC
Authors: Aliu E. , Anderhub H. , Antonelli L. A. , Antoranz P. , Backes M. , Baixeras C. , Barrio J. A. , Bartko H. , Bastieri D. , Becker J. K. , Bednarek W. , Berger K. , Bernardini E. , Bigongiari C. , Biland A. , Bock R. K. , Bonnoli G. , Bordas P. , Bosch-Ramon V. , Bretz T. , Britvitch I. , Camara M. , Carmona E. , Chilingarian A. , Commichau S. , Contreras J. L. , Cortina J. , Costado M. T. , Covino S. , Curtef V. , Dazzi F. , De Angelis A. , De Cea del Pozo E. , de los Reyes R. , De Lotto B. , De Maria M. , De Sabata F. , Delgado Mendez C. , Dominguez A. , Dorner D. , Doro M. , Elsässer D. , Errando M. , Fagiolini M. , Ferenc D. , Fernandez E. , Firpo R. , Fonseca M. V. , Font L. , Galante N. , Garcia Lopez R. J. , Garczarczyk M. , Gaug M. , Goebel F. , Hadasch D. , Hayashida M. , Herrero A. , Höhne D. , Hose J. , Hsu C. C. , Huber S. , Jogler T. , Kranich D. , La Barbera A. , Laille A. , Leonardo E. , Lindfors E. , Lombardi S. , Longo F. , Lopez M. , Lorenz E. , Majumdar P. , Maneva G. , Mankuzhiyil N. , Mannheim K. , Maraschi L. , Mariotti M. , Martinez M. , Mazin D. , Meucci M. , Meyer M. , Miranda J. M. , Mirzoyan R. , Moles M. , Moralejo A. , Nieto D. , Nilsson K. , Ninkovic J. , Otte N. , Oya I. , Paoletti R. , Paredes J. M. , Pasanen M. , Pascoli D. , Pauss F. , Pegna R. G. , Perez-Torres M. A. , Persic M. , Peruzzo L. , Piccioli A. , Prada F. , Prandini E. , Puchades N. , Raymers A. , Rhode W. , Ribó M. , Rico J. , Rissi M. , Robert A. , Rügamer S. , Saggion A. , Saito T. Y. , Salvati M. , Sanchez-Conde M. , Sartori P. , Satalecka K. , Scalzotto V. , Scapin V. , Schweizer T. , Shayduk M. , Shinozaki K. , Shore S. N. , Sidro N. , Sierpowska-Bartosik A. , Sillanpää A. , Sobczynska D. , Spanier F. , Stamerra A. , Stark L. S. , Takalo L. , Tavecchio F. , Temnikov P. , Tescaro D. , Teshima M. , Tluczykont M. , Torres D. F. , Turini N. , Vankov H. , Venturini A. , Vitale V. , Wagner R. M. , Wittek W. , Zabalza V. , Zandanel F. , Zanin R. , Zapatero J. , de Jager O.C. , de Ona Wilhelmi E.
Published: October 2008

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric γ-ray Imaging Cherenkov (MAGIC) telescope to 25 giga–electron volts. In this configuration, we detected pulsed γ-rays from the Crab pulsar that were greater than 25 giga–electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.
Detection of GTP-Tubulin Conformation in Vivo Reveals a Role for GTP Remnants in Microtubule Rescues
Authors: Dimitrov Ariane , Quesnoit Mélanie , Moutel Sandrine , Cantaloube Isabelle , Poüs Christian , Perez Franck
Published: October 2008

Microtubules display dynamic instability, with alternating phases of growth and shrinkage separated by catastrophe and rescue events. The guanosine triphosphate (GTP) cap at the growing end of microtubules, whose presence is essential to prevent microtubule catastrophes in vitro, has been difficult to observe in vivo. We selected a recombinant antibody that specifically recognizes GTP-bound tubulin in microtubules and found that GTP-tubulin was indeed present at the plus end of growing microtubules. Unexpectedly, GTP-tubulin remnants were also present in older parts of microtubules, which suggests that GTP hydrolysis is sometimes incomplete during polymerization. Observations in living cells suggested that these GTP remnants may be responsible for the rescue events in which microtubules recover from catastrophe.
An epidemiological study of football (soccer) injuries in Benin City, Nigeria
Authors: Azubuike S O , Okojie O H
Published: October 2008

Background:

The increase in popularity of soccer and expectations from players make significant numbers of soccer injuries conceivable. Concerns have been expressed about the demand placed on the modern-day footballer and translation of these physical and mental demands into injuries. Despite the popularity and importance of the game of soccer in Benin, no detailed study on the occurrence of soccer injury has been carried out.

Objective:

The study sets out to describe and assess the determinants and effects of soccer injuries.

Methodology:

Seven clubs (196 players) from the premiership, professional, national and state amateur clubs were studied using a descriptive cross-sectional study design. A pre-designed semi-structured questionnaire and key informants interview guide were used for data collection. Descriptive and inferential statistics were used in the analysis, with significant levels generally taken at 5% level of significance.

Results:

A total of 196 players sustained 204 injuries with a prevalence rate of 81.6%. More injuries were recorded during matches (46.1%) than during training (36.8%). Injuries occurring by body contact constituted 62.3% of the total injuries. The ankle (25%) was the most affected site, followed by the knee (20.1%), while sprain injury (33.3%) and strain (13.2%) were the commonest injury types. Moderate injury (28.9%) was the highest form of severity recorded. Recurrent injury accounted for 38.8% of injuries, occurring more in training (44.9%) than in matches (36.7%). A greater percentage (86.8%) of the injuries were traumatic in nature, with tackling (44.6%) being the commonest mechanism. Defenders (34.3%) and strikers (31.4%) had higher injury occurrence. The association between the player’s role and the mechanism of injury was significant (p = 0.02), while that between weather condition and injury type was very significant (p = 0.004). Moreover, the association between experience and mechanism of injury was extremely significant (p<0.001). The study also shows that injury has economic, physical and psychological impacts on players.

Conclusion:

A prevalence rate of 81.6% was recorded. Sprain was the leading injury type, while the ankle was the most affected anatomical site. Factors such as weather, previous injury, experience, role, and activity tend to influence injury occurrence. Soccer injury also has economic, physical and psychological implications. It is therefore recommended that preventive measures such as adequate treatment of injuries, full rehabilitation after injuries, use of protective equipment, appropriate exercises and warm-ups, continual team education on injury managements and skill improvement, etc., be utilised and enforced to protect this group of sport workers.
An Optimization Model for Balancing Economic–Environmental Systems
Authors: Panagiotakopoulos Demetrios
Published: October 2008

Resolutions of conflicts within an economic–environmental system are challenges that engineers often face, since they are expected to provide the decision-makers with the trade-offs involved among the various levels of the waste generating economic activities, the resulting environmental quality, and spending for attaining it. This paper presents a methodology for resolving such conflicts. The methodology is based on a waste management network model which allows for an efficient and systematic search among the possible waste management systems linking generated wastes with the environment, and also for their evaluation on the basis of the balance of their burdens on the various environmental forms and the operating budget. Recycling, discharge and effluent standards, charges, damage costs, and various budgeting schemes can be handled. Dynamic analyses for long-range financial planning under an expected increasing rate of waste generation are possible. For a simple hypothetical case, the model is set up, available data are reduced to usable forms', and trade-off curves are obtained through simulation analysis.
Thermal Stresses in Steel–Concrete Composite Bridges
Authors: Berwanger Carl , Symko Yaroslav
Published: October 2008

The objective was to determine experimentally and analytically two-dimensional steady-state temperature distributions produced in the cross-sectional planes of steel–concrete composite simple span bridges. The upper and lower surfaces were exposed to different temperatures.The research included the development of finite element solutions for steady-state temperature distributions from known boundary conditions and the calculation of strains and stresses. Temperature and stress distributions were generally nonlinear with linear strains through the finite elements. Temperatures were predicted to ±1 °F (±5/9 °C). The experimental strains are linear through the composite section, with the computed finite element strains giving generally slightly higher stresses. The conventional and finite element method computed stresses were compared.For positive curvature, the conventional method underestimated the compressive stress in the top flange by about 20% while the bottom flange tensile stresses were identical. For negative curvature, the conventional method overestimated the bottom flange compressive stresses between 15 to 27% and the top flange tensile stresses from 10 to 61%. The concrete slab stresses were overestimated for positive curvature and slightly underestimated for negative curvature. Slab stresses were relatively small when compared with the permissible concrete stress. Temperature stresses in the steel beam were shown to be significantly large, about 30% of the permissible steel stress, to warrant consideration in the design of these bridges. The stresses were calculated for short term steady-state temperatures. Transient conditions existing in the field produce greater thermal stresses.
Tools for Urban Land Use—Transport Strategy Planning
Authors: Hutchinson B. G.
Published: October 2008

Urban strategy planning studies are directed towards the estimation of the transport demand and other servicing implications of a range of urban development alternatives. These studies attempt to isolate those concepts which might lead to costly and intractable infrastructure problems. Several analytical tools that may be used to explore the implications of strategic development alternatives are described.A land use-transport model is described which may be used to estimate the implications of alternative public development policies. These policies may include servicing and transportation options, basic and service employment location alternatives, and zoning. The model calculates an internally consistent co-distribution of population and employment along with the associated travel demands for each set of public policies. A corridor-level traffic assignment technique is described which may be used along with the land use-transport model to develop corridor travel demand estimates for each development concept. Computer-based procedures for estimating the servicing requirements of alternative development concepts are also described. These procedures directly employ the land use allocations calculated by the land use model. The use of the analytical tools is illustrated with information from the Hamilton area.
Approximations for Natural Frequencies of Interconnected Walls and Frames
Authors: Rutenberg A. , Heidebrecht A. C.
Published: October 2008

Several approximate formulae for the determination of natural frequencies of interconnected walls and frames with uniform mass and stiffness throughout their height are compared and the range of their applicability discussed. It is found that none of the approximations give high accuracy for the entire range of the stiffness parameter αH encountered in practice. It is recommended that for the fundamental frequency the flexural beam approximation be used for the lower end of the range (αH < 7) and the large αH asymptotic formula be used elsewhere. This ensures that the error never exceeds 5%. For the higher modes there is a choice between three approximations, the maximum error associated with each being practically identical: 10% in the second mode and 5% in the third.
Dikes on permafrost: predicting thaw and settlement
Authors: Brown W. G. , Johnston G. H.
Published: October 2008

Prediction of permafrost thaw and settlement of dikes constructed on perennially frozen ground is important for maintenance and foundation stability. A method is developed for estimating the rates of thaw and settlement, based on simple heat conduction theory. A comparison of calculated and observed rates of thaw for dikes on ice-rich foundation soils at the Kelsey Generating Station in northern Manitoba shows good agreement and indicates that thaw and settlement rates can be predicted with reasonable accuracy.
Disturbances to the tundra and forest tundra environment of the western Arctic
Authors: Mackay J. Ross
Published: October 2008

The more important physical disturbances to the tundra environment are discussed with examples. Thermokarst subsidence, not thermal erosion, is shown to be the dominant result of man-induced disturbances, such as those caused by the bulldozing of seismic lines and firebreaks. It is shown that a clear distinction between thermokarst subsidence and thermal erosion is necessary, if the causes of the disturbances are to be prevented and minimized, or the results treated. The typical surface disturbance to the tundra results in a deepening of the active layer. Therefore, foreknowledge of the effect of a disturbance on deepening the active layer, together with information on the ice content of the permafrost affected, makes it possible to predict the amount of thermokarst subsidence likely to take place. Three practical examples of three types of ground disturbance are given: a fire near Inuvik, N.W.T.; a patch of vegetation trampled and killed by a dog at Garry Island, N.W.T.; and seepage down a walking trail in an ice-wedge area at Garry Island, N.W.T. The effects of the disturbances are illustrated and discussed.
KNOWLEDGE-BASED REASONING ENHANCED CONTROL SYSTEM FORIN-SITUBIOREMEDIATION PROCESSES
Authors: HU ZHIYING , CHAN CHRISTINE W. , HUANG GORDON H.
Published: October 2008

This study describes the development of a dynamic knowledge-based reasoning-enhanced model predictive control system (KBRECS) for in-situ bioremediation processes. The automated control system balances the complex physical, chemical, and biological processes involved in the remediation process while minimizing overall cost of the entire remediation process. The control system includes an optimization subsystem and a monitoring subsystem. The optimization subsystem consists of a simulation model supported by an optimization function which is designed to generate a series of optimal control actions. The monitoring subsystem is a knowledge-based system which is designed to monitor and adjust the online control actions. The numerical simulation model describes the fate and transport of the subsurface contaminants. The optimization function is a constrained, nonlinear function that has been implemented using a genetic algorithm (GA). Intermediate genetic algorithm individuals are indexed and stored in the knowledge base, thereby reducing search times for values to replace the unqualified schemes used by the monitoring subsystem. The system was applied to a lab experiment and compared with the control system presented in [9]. The results indicated that the knowledge based reasoning system enhanced the control system by generating an appropriate control strategy and adjusting control actions promptly. This helps to enhance efficiency in control of the in-situ bioremediation process at petroleum-contaminated groundwater systems.
ENSEMBLE EMPIRICAL MODE DECOMPOSITION: A NOISE-ASSISTED DATA ANALYSIS METHOD
Authors: WU ZHAOHUA , HUANG NORDEN E.
Published: October 2008

A new Ensemble Empirical Mode Decomposition (EEMD) is presented. This new approach consists of sifting an ensemble of white noise-added signal (data) and treats the mean as the final true result. Finite, not infinitesimal, amplitude white noise is necessary to force the ensemble to exhaust all possible solutions in the sifting process, thus making the different scale signals to collate in the proper intrinsic mode functions (IMF) dictated by the dyadic filter banks. As EEMD is a time–space analysis method, the added white noise is averaged out with sufficient number of trials; the only persistent part that survives the averaging process is the component of the signal (original data), which is then treated as the true and more physical meaningful answer. The effect of the added white noise is to provide a uniform reference frame in the time–frequency space; therefore, the added noise collates the portion of the signal of comparable scale in one IMF. With this ensemble mean, one can separate scales naturally without any a priori subjective criterion selection as in the intermittence test for the original EMD algorithm. This new approach utilizes the full advantage of the statistical characteristics of white noise to perturb the signal in its true solution neighborhood, and to cancel itself out after serving its purpose; therefore, it represents a substantial improvement over the original EMD and is a truly noise-assisted data analysis (NADA) method.