bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety Impact of Truck Lane Restrictions on Multilane Freeways
Authors: Fontaine Michael D. , Bhamidipati Chiranjivi Sarma , Dougald Lance E.
Published: August 2009

Many states have implemented truck lane restrictions in an attempt to improve safety and mobility on freeways. These restrictions typically prohibit trucks from traveling in the median (left-most) lane of multi-lane highways; the restriction potentially increases passing opportunities and reduces negative interactions between slow-moving trucks and faster-moving vehicles. Virginia has restricted trucks from the median lane of some interstates with three or more lanes by direction since 1997, but no systematic evaluation of the safety impact of the restrictions has been conducted. Evaluations of similar restrictions in other states have yielded contradictory findings, but those studies often used a limited data set. An empirical Bayes’ analysis of Virginia's restrictions was performed by using 6 years of crash data from 22 sites with restrictions and 16 similar sites without restrictions. The analysis showed that a breakpoint in safety performance occurred around 10,000 vehicles per day per lane. Facilities where the volume was below this threshold had significantly fewer crashes than anticipated, averaging a 13% reduction in total crashes and a 32% reduction in fatal and injury crashes. Sites where the volume exceeded this threshold had increases in total crashes and fatal or injury crashes of 28% and 23%, respectively. A detailed analysis of crashes on the higher-volume roads was conducted to screen out crashes in which the restrictions likely played no role. That analysis showed that the number of truck-involved crashes was still significantly higher than predicted, indicating that safety on higher-volume roads may be negatively affected by truck lane restrictions.
Bayesian Analysis of the Effect of Horizontal Curvature on Truck Crashes Using Training and Validation Data Sets
Authors: Schneider William H. , Zimmerman Karl , Van Boxel Dan , Vavilikolanu Srutha
Published: August 2009

The research on the effects of roadway geometry on truck crashes is relatively limited in comparison with predictive models developed for total vehicle crashes. The most common predictive models currently used are Poisson and negative binomial models. This study uses a negative binomial model but applies the full Bayes’ methods for improving model performance. To use Bayes’ methods successfully, a learning process was used to develop a final model, which was then compared with a separate validation data set to verify its accuracy. The data set used for this study is based on rural two-lane collector and arterial horizontal curves in Ohio, comprising 15,390 observations from crash records between 2002 through 2006. Specific areas of interest in this study include the impact of shoulder width, horizontal curve radius, curve length, and other traffic parameters. The final results indicate a significant increase in truck crashes due to both horizontal curvature and passenger vehicle volumes. The final model's predictions were improved compared with the initial model, indicating that the learning process is a viable tool for future crash model development.
Roadside Alligators and the UMTRI Tire Debris Survey
Authors: Page Oliver , Woodrooffe John
Published: August 2009

Roadside alligators (also known as tire debris) are those unsightly shreds or fragments of rubber occasionally found on the nation's highways. The typical road user misunderstands the nature, extent, and contributing factors precipitating their formation. During the summer of 2007, the University of Michigan Transportation Research Institute conducted a national tire debris survey that involved the collection of 85,000 pounds of rubber and that provided 300 casings and 1,196 debris items for subsequent failure analysis. This paper discusses tire debris within the context of roadside litter, presents the tire debris survey methodology, and discusses the survey results. Overall, where the original equipment tread or retread status could be determined, original equipment accounted for 60%, and retreads accounted for 40% of the tire casings tested. For tire fragments, the status was 21% (original equipment) and 79% (retread). There was also a strong similarity for these same tire items in the ranking of probable causes of damage or failure. Road hazard or maintenance and operational factors were two of the top three probable causes of damage or failure. This result suggests that the majority of tire debris items found on the nation's highways is not a result of manufacturing or process deficiencies. However, two primary challenges remain: first, increasing public awareness about the origins, characteristics, and impacts of tire debris and, second, ensuring adherence to the highest standards in commercial driver truck operations and associated tire maintenance. Resolving these challenges can significantly reduce roadside tire debris and correct the understanding of highway users about the origins of the roadside alligator.
Effective Occupational Road Safety Programs
Authors: Murray Will , Ison Stephen , Gallemore Paul , Nijjar Harnam Singh
Published: August 2009

Despite an increasing interest in the potential of occupational road safety (often called fleet safety) to help governments improve road safety and to help organizations reduce human and asset damage, generate business efficiencies, ensure legal compliance, and cut costs, few published case studies of organizations have effectively managed this risk. This paper addresses this research gap by developing and evaluating an effective process for improving occupational road safety through a case study of Wolseley, which has invested in a detailed fleet program over the past 4 years on the basis of research and experience from around the world. A chronological case study approach describes Wolseley; the processes applied to review, benchmark, and manage its occupational road safety; and project implementation, project outcomes evaluation, and ongoing steps. It also sets out the lessons learned for researchers, policy makers, and other organizations. Over 4 years Wolseley has improved its process audit scores, halved its third-party collision rate, and gained a number of wider benefits by adopting a holistic approach. Despite several barriers, the ongoing program continues to show measurable successes on all its key performance indicators.
Safety Implications of Mandated Truck Speed Limiters on Freeways
Authors: Saccomanno Frank F. , Duong David , Cunto Flávio , Hellinga Bruce , Philp Chris , Thiffault Pierre
Published: August 2009

This paper presents the results of a study funded by Transport Canada to investigate the safety implications of mandated truck speed limiters. The study adopted a microscopic simulation approach that was applied to a number of maximum speed control strategies, including 105 km/h. The sensitivity of safety performance with respect to changes in geometric and traffic scenarios was investigated. The study found that truck speed limiters produced positive safety gains for different assumed volumes and percentages of trucks and different compliance levels. Under certain conditions, such as high volumes and high percentage of trucks, speed limiters produced a reduction in safety.
Driver Safety Programs
Authors: Bao Shan , Boyle Linda Ng
Published: August 2009

The goal of this study is to examine whether driver safety programs (DSPs) targeted toward older drivers can positively influence their behavior at intersections of rural expressways. Thirty-five older drivers participated in this study; 18 had attended a DSP, and 17 had not attended one. All participants were asked to perform three driving maneuvers (going straight across, making a left turn, and making a right turn) from two-lane minor roads. Drivers’ head movements and brake behavior immediately before entering these intersections were examined. The results showed that those drivers who had attended a DSP performed better to head movements and braking. DSP drivers stopped significantly earlier in response to upcoming intersections and were more likely to come to a complete stop, and they had significantly more head movements checking for traffic conflicts. These findings suggest that DSPs may encourage drivers to be more aware and less risky than drivers who do not attend a DSP. However, the results need to be considered because Iowa (the study location) does not give insurance reduction incentives for taking a DSP class, and therefore those who chose to attend may actually be safer drivers.
Traffic Sign Comprehensibility in an Aging Society
Authors: Kim Sungyop , Ulfarsson Gudmundur F. , Anton Karen R.
Published: August 2009

This paper analyzes the comprehensibility of current and experimental signs to indicate a photo-enforced traffic signal ahead. In Arnold, Missouri, four signalized intersections are photo enforced and have been indicated with the text-only “photo-enforced” regulatory sign posted below the traditional “signal ahead” warning sign. These signs were replaced with an experimental sign that indicates a photo-enforced traffic signal ahead with a single regulatory sign. The evaluation is performed by using three surveys: one for the currently approved signage and two for the experimental sign. The second survey was conducted shortly after installation of the experimental sign, and the third survey was conducted about 9 months after installation. The study found that older drivers (age 65+ years) have greater difficulty in comprehending both the current and experimental photo-enforced signage compared with younger drivers. However, older drivers’ comprehension of the experimental sign improved more over time than other drivers’ comprehension (62.5% to 75.8% correct comprehension for older versus 79.8% to 81.2% for others). The results indicate that the experimental sign has the potential to improve safety by better delivering its intended meaning, particularly to older drivers, but also that it may take older drivers more time than other drivers to learn about and comprehend new signs.
Analysis of Enforcement Techniques for DWI Checkpoints and Their Impact on Traffic Operations
Authors: Katz Bryan J. , Coffey Peter J. E. , Rakha Hesham A.
Published: August 2009

This paper documents a research project investigating the effects of various driving-while-intoxicated (DWI) checkpoint setup scenarios on overall traffic operations. According to NHTSA, 13,470 people were killed in alcohol-related crashes in 2006. Of the 13,470 fatalities, 64% involved drivers with a blood alcohol content of 0.08 or higher. For this reason, state and local police departments tend to conduct DWI checkpoints during the night, when police officers detain vehicles traveling on a roadway and interview drivers to determine suspicion of alcohol use. For planning and budgeting purposes, police departments need to be able to effectively plan a setup for DWI checkpoints. The goal of the project is to provide police departments with data and methodologies to analyze the impact of their checkpoints on traffic operations. Seven scenarios were investigated on the basis of interviews with several police departments: one officer stopping every vehicle, one officer stopping every second vehicle, one officer stopping every fifth vehicle, one officer stopping every tenth vehicle, two officers stopping every vehicle, four officers stopping every vehicle, and four officers stopping every second vehicle. Each scenario was varied to include 50, 100, 150, 200, 300, 400, 500, 600, 700, and 800 vehicles per hour (or vehicles per hour per lane) to obtain a wide range of limiting values after which DWI checkpoints would cause extraordinary amounts of delay. The paper includes the results for each scenario that can be used by police departments to recognize the potential impacts on vehicle delay.
A Legal Approach to Reduce Red Light Running Crashes
Authors: Awadallah Faisal
Published: August 2009

Indecision at the onset of the yellow interval at signalized intersections is one of the main problems facing drivers, especially inexperienced ones. This indecision is fairly justified because the yellow interval duration varies at intersections and also because of the optional use of the all-red interval and its varied duration. This indecision has serious safety consequences for signalized intersections. This paper provides a theoretically based legal approach for reducing red light running crashes. It stresses that all-red intervals are not necessarily a cure for red light running, especially when drivers come to expect an additional safety increment and many try to misuse it. A theoretical analysis has been performed to provide information to aid drivers in deciding how far from the stop line they must stop at the onset of the yellow interval, and when and where they should proceed to cross the intersection. This information is essential in reducing red light running. Delineation of a yellow transverse line at the calculated decision line is proposed as well as instituting a traffic regulation to stop if such line is not crossed at the onset of the yellow interval. Another proposed traffic ordinance is to “yield before go” to vehicles within the intersection at the onset of green. Theoretical, legal, and logical evidence for reducing red light running accidents is provided based on the proposed traffic ordinances. However, statistical valuation is as yet impossible because such traffic ordinances have not been implemented, and there are no before and after data on which to base a statistical analysis.
13C-NMR Assessment of the Pattern of Organic Matter Transformation during Domestic Wastewater Treatment by Autothermal Aerobic Digestion (ATAD)
Authors: Piterina Anna V. , Barlett John , Pembroke J.Tony
Published: August 2009

Abstract: The pattern of biodegradation and the chemical changes occurring in the macromolecular fraction of domestic sludge during autothermal thermophilic aerobic digestion (ATAD) was monitored and characterised via solid-state 13C-NMR CP-MAS. Major indexes such as aromaticity, hydrophobicity and alkyl/O-alkyl ratios calculated for the ATAD processed biosolids were compared by means of these values to corresponding indexes reported for sludges of different origin such as manures, soil organic matter and certain types of compost. Given that this is the first time that these techniques have been applied to ATAD sludge, the data indicates that long-chain aliphatics are easily utilized by the microbial populations as substrates for metabolic activities at all stages of aerobic digestion and serve as a key substrate for the temperature increase, which in turn results in sludge sterilization. The ATAD biosolids following treatment had a prevalence of O-alkyl domains, a low aromaticity index (10.4%) and an alkyl/O-alkyl ratio of 0.48 while the hydrophobicity index of the sludge decreased from 1.12 to 0.62 during the treatment. These results have important implications for the evolution of new ATAD modalities particularly in relation to dewatering and the future use of ATAD processed biosolids as a fertilizer, particularly with respect to hydrological impacts on the soil behaviour.
Design of a Water Environment Monitoring System Based on Wireless Sensor Networks
Authors: Jiang Peng , Xia Hongbo , He Zhiye , Wang Zheming
Published: August 2009

A water environmental monitoring system based on a wireless sensor network is proposed. It consists of three parts: data monitoring nodes, data base station and remote monitoring center. This system is suitable for the complex and large-scale water environment monitoring, such as for reservoirs, lakes, rivers, swamps, and shallow or deep groundwaters. This paper is devoted to the explanation and illustration for our new water environment monitoring system design. The system had successfully accomplished the online auto-monitoring of the water temperature and pH value environment of an artificial lake. The system's measurement capacity ranges from 0 to 80 °C for water temperature, with an accuracy of ±0.5 °C; from 0 to 14 on pH value, with an accuracy of ±0.05 pH units. Sensors applicable to different water quality scenarios should be installed at the nodes to meet the monitoring demands for a variety of water environments and to obtain different parameters. The monitoring system thus promises broad applicability prospects.
ICPC-2 defined pattern of illnesses in a practice-based research network in an urban city in West Africa
Authors: Ayankogbe Olayinka O. , Oyediran Muriel A. , Oke David A. , Arigbabu Surajudeen O. , Osibogun Akin A.
Published: August 2009

Background: In optimising the health of individuals, families and communities, attention should be focused on the clinical processes at medical facilities based in the community. Networks of general and family practices offer this unique opportunity. In establishing the burden of diseases in a community, the traditional classification used is the International Classification of Diseases. This study uses the International Classification of Primary Care. The aim of the study was to document the pattern of illnesses presenting in general/family physician practices in a city in Nigeria.Method: A nine-item interviewer-administered questionnaire containing closed-ended questions was administered to 881 patients presenting at 67 private general/family practice clinics/hospitals in 15 local government areas of urban Lagos by trained general practitioners, using the ICPC-2 pager, which asks for socio-demographic information, reasons for the presentation, and the provisional diagnosis within a 24-hour period.Results: Children younger than five years accounted for 20.4% of those presenting, while 25- to 39-year-olds accounted for 44.4%. Geriatric patients (60 years and older) comprised 3.0%. Social classes 1 to 4 accounted for 36.8% of the patients, while social classes 5 to 8 accounted for 43.2%. Of all the patients, 18.7 % earned less than 1 US$/day. The seven topmost reasons for visiting the medical practice/clinic/hospital were: General and unspecified 23.1%; pregnancy, child bearing and family planning 13.9%; respiratory problems 10.9%; problems related to the digestive system 9.6%; musculoskeletal 5.6%; Skin 4.4%; and neurological problems 4.2%.Conclusion: The skills of general/family practitioners in West Africa and on the rest of the continent should concentrate on general and unspecified illnesses, routine and emergency maternal and child care, and problems related to the respiratory, digestive, musculoskeletal, skin and neurological systems.
Functional Chromium Wheel‐Based Hybrid Organic–Inorganic Materials for Dielectric Applications
Authors: Di Noto Vito , Boeer Angelika B. , Lavina Sandra , Muryn Christopher A. , Bauer Matthias , Timco Grigore A. , Negro Enrico , Rancan Marzio , Winpenny Richard E. P. , Gross Silvia
Published: August 2009

The first example of organic–inorganic hybrid materials based on the embedding of a chromium–nickel wheel cluster {[(n‐C3H7)2NH2]‐ [Cr7NiF8(O2C4H5)16]} (Cr7Ni) into poly(methyl methacrylate) (PMMA) and the characterization of the dielectric properties of the obtained material is described. By an optimized copolymerization of the methacrylate‐functionalized chromium–nickel wheel with methyl methacrylate in a cluster/monomer 1:200 molar mixture, a homogeneous hybrid material CrNi_MMA200 is obtained. The electrical responses of the non‐doped PMMA and of the hybrid material were studied by broadband dielectric spectroscopy (BDS) from 0.01 Hz to 10 MHz and over the temperature range of 5–115 °C. The permittivity profiles reveal two relaxation peaks in the materials, which correspond to the α and β relaxation modes of the PMMA matrix. The position of these modes shifts toward higher frequencies as temperature increases. BDS is a powerful tool revealing the intimate miscibility of the various components of the hybrid material, thus indicating that, on a molecular scale, the material proposed is a homogeneous system. Finally, a value of the dielectric constant of 2.9 at 25 °C and 1 kHz is determined. This value is noticeably lower than the value of 3.2 obtained for pristine PMMA prepared following the same synthesis protocol. Thus, these results classify the hybrid CrNi_MMA200 as an appealing starting material for the development of dielectric polymeric layers for the development of innovative capacitors, transistors, and other microelectronic devices. The vibrational properties of the hybrid materials are investigated by Fourier‐transform infrared (FT‐IR) and Raman spectroscopy, whereas the thermal behavior is analyzed by thermogravimetric analysis (TGA). Swelling experiments are used to qualitatively evaluate the crosslinking density of the hybrid materials. The integrity of the wheels once embedded in the macromolecular backbone is confirmed by extended X‐ray absorption fine structure (EXAFS) and electron spin resonance (EPR) spectroscopic measurements.
Template Deformation‐Tailored ZnO Nanorod/Nanowire Arrays: Full Growth Control and Optimization of Field‐Emission
Authors: Zeng Haibo , Xu Xijin , Bando Yoshio , Gautam Ujjal K. , Zhai Tianyou , Fang Xiaosheng , Liu Baodan , Golberg Dmitri
Published: August 2009

Here, a facile and effective route toward full control of vertical ZnO nanorod (NR)/nanowire (NW) arrays in centimeter‐scale areas and considerable improvement of field‐emission (FE) performance is reported. Controlled deformation of colloidal crystal monolayer templates is introduced by heating near glass‐transition temperature. The NR/NW density, uniformity, and tapering were all adjusted through selection of template size and deformation, and electrolyte composition. In line with the adjustments, the field‐emission performance of the arrays is significantly improved. A low turn‐on electric field of 1.8 V µm−1, a field‐enhancement factor of up to 5 750, and an emitting current density of up to 2.5 mA cm−2 were obtained. These improved parameters would benefit their potential application in cold‐cathode‐based electronics.
Computational study of staged membrane reactor configurations for methane steam reforming. II. Effect of number of stages and catalyst amount
Authors: Caravella Alessio , Di Maio Francesco Paolo , Di Renzo Alberto
Published: August 2009

The present work complements part I of this article and completes a computational analysis of the performances of staged membrane reactors for methane steam reforming. The influence of the number of stages and catalyst amount is investigated by comparing the methane conversion and hydrogen recovery yield achieved by an equisized‐staged reactor to those of an equivalent conventional membrane reactor for different furnace temperatures and flow configurations (co‐ and counter‐current). The most relevant result is that the proposed configuration with a sufficiently high number of stages and a significantly smaller catalyst amount (up to 70% lower) can achieve performances very close to the ones of the conventional unit in all the operating conditions considered. This is equivalent to say that the staged configuration can compensate and in fact substitute a significant part of the catalyst mass of a conventional membrane reactor. To help the interpretation of these results, stage‐by‐stage temperature and flux profiles are examined in detail. Then, the quantification of the performance losses with respect to the conventional reactor is carried out by evaluating the catalyst amount possibly saved and furnace temperature reduction. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Pathologic changes of skin and hair in ankyloblepharon‐ectodermal defects‐cleft lip/palate (AEC) syndrome
Authors: Dishop Megan K. , Bree Alanna F. , Hicks M. John
Published: August 2009

Ankyloblepharon‐Ectodermal defects‐Cleft lip/palate (AEC) syndrome is a rare disorder of hair, skin, nails, and dentition caused by mutations in the p63 gene. Pathologic changes of skin and hair in AEC syndrome have previously been described in isolated case reports. Biopsies of normal and lesional skin from 19 patients with AEC syndrome were examined by light microscopy. Hair samples from 18 patients were examined by light and scanning electron microscopy. Histopathologic changes identified within the skin biopsies from clinically unaffected skin include mild atrophy, focal orthokeratosis, and mild superficial perivascular lymphocytic dermatitis. Scattered melanophages in the superficial and deep dermis likely reflect post‐inflammatory change. One patient with a unilateral eruption of monomorphic papulopustules on the chest and shoulder demonstrated an acneiform intraepidermal pustule. Examination of the hair shafts revealed atrophy and loss of melanin pigment in some of the patients. Structural abnormalities included pili torti, pili trianguli et canaliculi, and irregular indentation and shallow grooves. Skin and hair findings in AEC syndrome were found to be generally similar to those described in other ectodermal dysplasia syndromes and corroborates the few prior descriptions in AEC syndrome specifically. © 2009 Wiley‐Liss, Inc.
Hypervitaminosis A in experimental nonhuman primates: evidence, causes, and the road to recovery
Authors: Dever Joseph T. , Tanumihardjo Sherry A.
Published: August 2009

One of the great underlying assumptions made by all scientists utilizing primate models for their research is that the optimal nutritional status and health of the animals in use has been achieved. That is, no nutrient deficiency or excess has compromised their health in any detectable way. To meet this assumption, we rely on the National Research Council's (NRC's) nutritional recommendations for nonhuman primates to provide accurate guidance for proper dietary formulations. We also rely on feed manufacturers to follow these guidelines. With that in mind, the purpose of this commentary is to discuss three related points that we believe have significant ramifications for the health and well being of captive primates as well as for their effective use in biomedical research. First, our laboratory has shown that most experimental primates are likely in a state of hypervitaminosis A. Second, it is apparent that many primate diets are providing vitamin A at levels higher than the NRC's recommendation. Third, the recommendation itself is based on inadequate information about nutrient needs and is likely too high, especially when compared with human requirements. Am. J. Primatol. 71:813–816, 2009. © 2009 Wiley‐Liss, Inc.
Ohmic heating of dairy fluids—effects of local electric field on temperature distribution
Authors: Tham Heng Jin , Chen XiaoDong , Young Brent R. , Duffy Geoffrey G.
Published: August 2009

This paper presents the heat transfer model of a continuous flow ohmic heating process. The model fluid used was a mixture of reconstituted skimmed milk and whey protein concentrate solution. Two‐dimensional numerical simulations of an annular ohmic heater were performed using a general purpose partial differential equation solver, FlexPDE. The momentum, energy, and electrical equations were solved for a laminar flow regime. Two models were used to determine the volumetric heating rate, one taking into account the local electric field by solving the Laplace equation while another model assumes an average voltage gradient applied between the two electrodes. Results show that while the wall temperature distribution is different for the two cases, the bulk fluid temperature and the average outlet temperature are the same. The predicted temperatures generally agree well with the measured temperatures. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Dynamic state reconciliation and model‐based fault detection for chemical processes
Authors: Olivier‐Maget Nelly , Hétreux Gilles , Le Lann Jean Marc , Le Lann Marie Véronique
Published: August 2009

In this paper, we present a method for the fault detection based on the residual generation. The main idea is to reconstruct the outputs of the system from the measurements using the extended Kalman filter. The estimations are compared to the values of the reference model and so, deviations are interpreted as possible faults. The reference model is simulated by the dynamic hybrid simulator, PrODHyS. The use of this method is illustrated through an application in the field of chemical processes. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Novel nickel‐based catalyst for low temperature hydrogen production from methane steam reforming in membrane reformer
Authors: Chen Yazhong , Cui Peng , Xiong Guoxing , Xu Hengyong
Published: August 2009

Hydrogen production from various hydrocarbon fuels, particularly biomass‐derived fuels, has attracted worldwide attention due to its potential for application to fuel cells, a device which converts chemical energy into electricity efficiently and cleanly. However, current technology, such as natural gas steam reforming, could not meet the specific requirements of hydrogen for fuel cells. Therefore, novel processes are intensively investigated, aiming to develop economic and efficient ones for the specific purpose. An important direction is the integrated membrane reformer for one‐step high‐purity hydrogen production. However, for the commercial realization of this technology, there are still some difficulties to overcome. By comparison with previous investigations with a similar membrane, this work showed that catalyst also played an important role in determining membrane reformer performance. We proposed that when thickness of membrane was several micrometers, the permeance of membrane became less important than the kinetics of catalyst, due to the fact that under such conditions, hydrogen permeation rate was faster than the kinetics of steam reforming reaction when commercial catalyst was applied, but further evidence is indispensable. In this initial work, we focused on developing efficient nickel catalyst for low temperature steam reforming. Nickel‐based catalyst was developed by deposition–coprecipitation and used as pre‐reduced, showing high performance for methane steam reforming at low temperatures and good durability, which may find practical application for the integrated membrane reforming process. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Production of hydrogen via glycerol steam reforming in a Pd‐Ag membrane reactor over Co‐Al2O3 catalyst
Authors: Iulianelli A. , Longo T. , Liguori S. , Basile A.
Published: August 2009

Generally, biodiesel fuel, when converted from vegetables oils, produces around 10 wt% of glycerol as a byproduct, which could be used for producing hydrogen by a steam‐reforming reaction. Different scientific works have been realized in conventional reactors on the steam reforming of glycerol (GSR) in the aqueous or the gas phase. High reaction pressure and a relatively small catalyst deactivation are noticed when GSR is carried out in an aqueous phase, whereas the catalyst deactivation is the main disadvantage in the gas phase. In this work, GSR reaction was performed in a perm‐selective Pd‐Ag membrane reactor (MR) packed with a Co‐Al2O3 commercial catalyst in order to extract a CO‐free hydrogen stream and also enhance the performances in terms of glycerol conversion and hydrogen yield with respect to a traditional reactor (TR), both working at weight hourly space velocity (WHSV) = 1.01 h−1, 400 °C and H2O/C3H8O3 = 6/1. In MR, a maximum glycerol conversion of around 45.0% was achieved at 1.0 bar as reaction pressure, whereas it was around 94% at 4.0 bar. Moreover, as best value, more than 60.0% of CO‐free hydrogen recovery was achieved in the MR at 4.0 bar and 22.8 of sweep factor (sweep gas to glycerol ratio). Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of surface defects in Pd‐based membranes on the performance of a membrane reactor
Authors: Caravella Alessio , Di Maio Francesco Paolo , Di Renzo Alberto
Published: August 2009

In this work, the influence of superficial defects over the surface of a Pd‐based membrane is analyzed in a membrane reactor for the methane steam‐reforming process. In order to include the presence of defects in the permeation, a previous model of a defect‐free Pd‐based membrane reactor is extended and integrated to include a variable portion of area with defects in the form of pinholes. As a consequence, two different permeation mechanisms are taken into account, one through the Pd‐based surface and the other one through the pinholes, where a Knudsen‐like transport is considered to occur. The presence of the Knudsen transport causes the membrane separation factor between the hydrogen and the other species involved in the process to decrease, affecting the reactor performances significantly. Three reactor performance indices are investigated as functions of the fraction of the defected area and the mean pore diameter of defects, namely methane conversion, the hydrogen recovery factor, the hydrogen recovery yield and the net purity of hydrogen in the permeate. The results show that the hydrogen recovery factor is positively influenced by the decrease in hydrogen selectivity, whilst methane conversion and hydrogen net purity decrease significantly with it. On the contrary, regarding the hydrogen recovery yield, it is shown that in certain conditions (low furnace temperature, ≈ 550 °C) it decreases with hydrogen selectivity. However, it increases again at higher furnace temperatures (≈650 °C). Globally, this investigation helps in identifying acceptable defect levels on a Pd‐based membrane for methane steam‐reforming applications and highlights that even a very small defect level (in terms of the pinhole diameter and/or amount of the defected area) can importantly compromise the reactor performances. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Thermally stable polyureas and poly(urea‐imide)s containing zinc and nickel napthtrien complexes
Authors: Sridaeng Duangruthai , Chantarasiri Nuanphun
Published: August 2009

Two new napthtrien metal complexes, MNapth2trien; where M = Zn and Ni, were synthesized and used for the synthesis of metal‐containing polyureas and poly(urea‐imide)s. MNapth2trien underwent polymerization reaction with two diisocyanates, namely, 4,4′‐diphenylmethane diisocyanate and isophorone diisocyanate to yield polyureas. Poly(urea‐imide)s were obtained by the synthesis of metal‐containing isocyanate‐terminated polyurea prepolymers from the reaction between MNapth2trien and excess diisocyanates, which could then undergo further reaction with different dianhydrides. The dianhydrides used were pyromellitic dianhydride and benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride. The polymers were characterized by infrared, nuclear magnetic resonance, elemental analysis, X‐ray diffraction, solubility, and viscosity. Glass transition temperature of the polymers was obtained from differential scanning calorimetry and dynamic mechanical thermal analysis. Thermal stability of polymers was studied by thermogravimetric analysis in air. It was found that the resulting metal‐containing polymers exhibited good thermal stability. Initial decomposition temperatures of the polymers depend on the amount of MNapth2trien in the polymer composition. Char yields of metal‐containing poly(urea‐imide)s are higher than those of metal‐containing polyureas. Most metal‐containing polymers show good solubility in organic solvents. Shore D hardness test indicates that metal‐containing poly(urea‐imide)s are hard materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Miscibility, crystallization, and mechanical properties of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)/ poly(butylene succinate) blends
Authors: Zhu Wenfu , Wang Xiaojuan , Chen Xianyu , Xu Kaitian
Published: August 2009

Naturally amorphous biopolyester poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) containing 21 mol % of 4HB was blended with semi‐crystal poly(butylene succinate) (PBS) with an aim to improve the properties of aliphatic polyesters. The effect of PBS contents on miscibility, thermal properties, crystallization kinetics, and mechanical property of the blends was evaluated by DSC, TGA, FTIR, wide‐angle X‐ray diffractometer (WAXD), Scanning Electron Microscope (SEM), and universal material testing machine. The thermal stability of P3/4HB was enhanced by blending with PBS. When PBS content is less than 30 wt %, the two polymers show better miscibility and their crystallization trend was enhanced by each other. The optimum mechanical properties were observed at the 5–10 wt % PBS blends. However, when the PBS content is more than 30 wt %, phase inversion happened. And the two polymers give lower miscibility and poor mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Prospects for management strategies of invasive crayfish populations with an emphasis on biological control
Authors: Freeman M. A. , Turnbull J. F. , Yeomans W. E. , Bean C. W.
Published: August 2009

The white‐clawed crayfish, Austropotamobius pallipes (Lereboullet), is the only freshwater crayfish indigenous to Great Britain and Ireland. It has a widespread, though declining distribution in England and parts of Wales but does not occur naturally in Scotland.

The North American signal crayfish, Pacifastacus leniusculus (Dana), is not native to Europe and was introduced to Britain in the 1970s. The signal crayfish out‐competes the native white‐clawed crayfish as it is larger and more aggressive. It is also responsible for the introduction and spread of crayfish plague, which has devastated white‐clawed crayfish populations in Europe.

Signal crayfish populations are causing significant changes to the equilibrium of native flora and fauna through increased grazing and predation pressures; they also contribute to habitat degradation through burrowing.

Manual removal of crayfish using traps and pond trials with biocides have met with moderate success in reducing crayfish numbers and containing populations. However, with new populations of signal crayfish being reported each year within the UK, there is now an urgent need to develop a strategy with which to eradicate or contain their spread.

Signal crayfish have populated many habitat types in the UK, each of which may require a different control strategy; hence no single strategy or universal solution is likely to be attainable.

Signal crayfish are susceptible to various biocides and microbial pathogens but significant scientific research will be required to develop safe biological control methods and integrated pest management (IPM) strategies to control these invasive organisms. Copyright © 2009 John Wiley & Sons, Ltd.
An update on cardiovascular malformations in congenital rubella syndrome
Authors: Oster Matthew E. , Riehle‐Colarusso Tiffany , Correa Adolfo
Published: August 2009

BACKGROUND: Congenital rubella syndrome (CRS) has long been characterized by the triad of deafness, cataract, and cardiovascular malformations (CVMs). While initial reports identified patent ductus arteriosus (PDA) as the primary CVM in CRS, the exact nature of the CVMs found in CRS has not been well established. METHODS: We searched the English literature from 1941 through 2008 to identify studies that used cardiac catheterization or echocardiography to evaluate the CVMs in CRS. RESULTS: Of the 121 patients in the 10 studies with catheterization data, 78% had branch pulmonary artery stenosis, and 62% had a PDA. In 49% of cases, both branch pulmonary artery stenosis and PDA were present, whereas isolated branch pulmonary artery stenosis and isolated PDA were found in 29 and 13% of cases, respectively. Of the 12 patients in the 10 studies with echocardiographic data, PDA was more common than branch pulmonary artery stenosis, but this finding is greatly limited by the small numbers of patients and limitations of echocardiography. Although published studies of CVMs in CRS have in general reported PDA as the CVM phenotype most commonly associated with CRS, among CRS cases evaluated by catheterization, branch pulmonary artery stenosis was actually more common than PDA. Moreover, although the combination of branch pulmonary artery stenosis and PDA was more common than either branch pulmonary artery stenosis or PDA alone, isolated branch pulmonary artery stenosis was twice as common as isolated PDA. CONCLUSION: Among children with suspected CRS, clinical evaluations for the presence of CVMs should include examinations for both branch pulmonary artery stenosis and PDA. Birth Defects Research (Part A), 2010. © 2009 Wiley‐Liss, Inc.
Multistate study of the epidemiology of clubfoot
Authors: Parker Samantha E. , Mai Cara T. , Strickland Matthew J. , Olney Richard S. , Rickard Russel , Marengo Lisa , Wang Ying , Hashmi S. Shahrukh , Meyer Robert E.
Published: August 2009

BACKGROUND: Although clubfoot is a common birth defect, with a prevalence of approximately 1 per 1000 livebirths, the etiology of clubfoot remains largely unknown. Studies of the prevalence and risk factors for clubfoot in the United States have previously been limited to specific states. The purpose of this study was to pool data from several birth defects surveillance programs to better estimate the prevalence of clubfoot and investigate its risk factors. METHODS: The 10 population‐based birth defects surveillance programs that participated in this study ascertained 6139 cases of clubfoot from 2001 through 2005. A random sample of 10 controls per case, matched on year and state of birth, was selected from birth certificates. Data on infant and maternal risk factors were collected from birth certificates. Prevalence was calculated by pooling the state‐specific data. Conditional logistic regression was used to investigate the association between risk factors and clubfoot. RESULTS: The overall prevalence of clubfoot was 1.29 per 1000 livebirths; 1.38 among non‐Hispanic whites, 1.30 among Hispanics, and 1.14 among non‐Hispanic blacks or African Americans. Maternal age, parity, education, and marital status were significantly associated with clubfoot. Maternal smoking and diabetes also showed significant associations. Several of these observed associations were consistent between surveillance programs. CONCLUSIONS: We estimated the prevalence of clubfoot using data from several birth defects programs, representing one‐quarter of all births in the United States. Our findings underline the importance of birth defects surveillance programs and their utility in monitoring population‐based prevalence and investigating risk factors. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.
Joint Estimation of Diagnostic Accuracy Measures for Paired Organs – Application in Ophthalmology
Authors: de Leon Alexander R. , Soo Andrea , Bonzo Daniel C. , Rudnisky Christopher J.
Published: August 2009

Diagnostic studies in ophthalmology frequently involve binocular data where pairs of eyes are evaluated, through some diagnostic procedure, for the presence of certain diseases or pathologies. The simplest approach of estimating measures of diagnostic accuracy, such as sensitivity and specificity, treats eyes as independent, consequently yielding incorrect estimates, especially of the standard errors. Approaches that account for the inter‐eye correlation include regression methods using generalized estimating equations and likelihood techniques based on various correlated binomial models. The paper proposes a simple alternative statistical methodology of jointly estimating measures of diagnostic accuracy for binocular tests based on a flexible model for correlated binary data. Moments' estimation of model parameters is outlined and asymptotic inference is discussed. The resulting estimates are straightforward and easy to obtain, requiring no special statistical software but only elementary calculations. Results of simulations indicate that large‐sample and bootstrap confidence intervals based on the estimates have relatively good coverage properties when the model is correctly specified. The computation of the estimates and their standard errors are illustrated with data from a study on diabetic retinopathy.
Hsp90 and co‐chaperones twist the functions of diverse client proteins
Authors: Zuehlke Abbey , Johnson Jill L.
Published: August 2009

Hsp90 molecular chaperones are required for the stability and activity of a diverse range of client proteins that have critical roles in signal transduction, cellular trafficking, chromatin remodeling, cell growth, differentiation, and reproduction. Mammalian cells contain three types of Hsp90s: cytosolic Hsp90, mitochondrial Trap‐1, and Grp94 of the endoplasmic reticulum. Each of the Hsp90s, as well as the bacterial homolog, HtpG, hydrolyze ATP and undergo similar conformational changes. Unlike the other forms of Hsp90, cytosolic Hsp90 function is dependent on a battery of co‐chaperone proteins that regulate the ATPase activity of Hsp90 or direct Hsp90 to interact with specific client proteins. This review will summarize what is known about Hsp90's ability to mediate the folding and activation of diverse client proteins that contribute to human diseases, such as cancer and fungal and viral infections. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 211–217, 2010.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Crassocolides G–M, Cembranoids from the Formosan Soft Coral Sarcophyton crassocaule
Authors: Huang Ho‐Cheng , Chao Chih‐Hua , Kuo Yao‐Haur , Sheu Jyh‐Horng
Published: August 2009

Seven new polyoxygenated cembranoids possessing an α‐methylene‐γ‐lactone group, crassocolides G–M (1–7, resp.), have been isolated from the AcOEt extract of the Formosan soft coral Sarcophyton crassocaule. The structures of compounds 1–7 were established by detailed spectroscopic analyses, including 2D‐NMR spectroscopy (1H,1H‐COSY, HMQC, HMBC, and NOESY), while the absolute configuration of 1 was determined using a modified reaction of Mosher's method. The cytotoxicity of compounds 1–7 against a limited panel of cancer cell lines was also determined.
Synthesis and Fungicidal Activities of New 1,2,4‐Triazolo[1,5‐a]pyrimidines
Authors: Chen Qiong , Liu Zu‐Ming , Chen Chao‐Nan , Jiang Li‐Li , Yang Guang‐Fu
Published: August 2009

A series of new acetohydrazone‐containing 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives were designed and synthesized for the purpose of searching for novel agrochemicals with higher fungicidal activity. Their in vitro fungicidal activities against Rhizoctonia solani were evaluated, and the most promising compound, 2‐[(5,7‐dimethyl[1,2,4]triazolo[1,5‐a]pyrimidin‐2‐yl)sulfanyl]‐2′‐[(2‐hydroxyphenyl)methylidene]acetohydrazide (2‐17), showed a lower EC50 value (5.34 μg ml−1) than that of commercial carbendazim (EC50=7.62 μg ml−1). Additionally, compound 2‐17 was also found to display broad‐spectrum fungicidal activities, and its EC50 value (4.56 μg ml−1) against Botrytis cinereapers was very similar to that of carbendazim. Qualitative structure–activity relationships (QSARs) of the synthesized compounds were also discussed.