bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and Biophysical Properties of a Triple-Stranded Beta-Helix Comprising the Central Spike of Bacteriophage T4
Authors: Buth Sergey , Menin Laure , Shneider Mikhail , Engel Jürgen , Boudko Sergei , Leiman Petr
Published: August 2015

Gene product 5 (gp5) of bacteriophage T4 is a spike-shaped protein that functions to disrupt the membrane of the target cell during phage infection. Its C-terminal domain is a long and slender β-helix that is formed by three polypeptide chains wrapped around a common symmetry axis akin to three interdigitated corkscrews. The folding and biophysical properties of such triple-stranded β-helices, which are topologically related to amyloid fibers, represent an unsolved biophysical problem. Here, we report structural and biophysical characterization of T4 gp5 β-helix and its truncated mutants of different lengths. A soluble fragment that forms a dimer of trimers and that could comprise a minimal self-folding unit has been identified. Surprisingly, the hydrophobic core of the β-helix is small. It is located near the C-terminal end of the β-helix and contains a centrally positioned and hydrated magnesium ion. A large part of the β-helix interior comprises a large elongated cavity that binds palmitic, stearic, and oleic acids in an extended conformation suggesting that these molecules might participate in the folding of the complete β-helix.
Plant Viruses as Nanoparticle-Based Vaccines and Adjuvants
Authors: Lebel Marie-Ève , Chartrand Karine , Leclerc Denis , Lamarre Alain
Published: August 2015

Vaccines are considered one of the greatest medical achievements in the battle against infectious diseases. However, the intractability of various diseases such as hepatitis C, HIV/AIDS, malaria, tuberculosis, and cancer poses persistent hurdles given that traditional vaccine-development methods have proven to be ineffective; as such, these challenges have driven the emergence of novel vaccine design approaches. In this regard, much effort has been put into the development of new safe adjuvants and vaccine platforms. Of particular interest, the utilization of plant virus-like nanoparticles and recombinant plant viruses has gained increasing significance as an effective tool in the development of novel vaccines against infectious diseases and cancer. The present review summarizes recent advances in the use of plant viruses as nanoparticle-based vaccines and adjuvants and their mechanism of action. Harnessing plant-virus immunogenic properties will enable the design of novel, safe, and efficacious prophylactic and therapeutic vaccines against disease.
Heuristic Methods for Reservoir Monthly Inflow Forecasting: A Case Study of Xinfengjiang Reservoir in Pearl River, China
Authors: Cheng Chun-Tian , Feng Zhong-Kai , Niu Wen-Jing , Liao Sheng-Li
Published: August 2015

Reservoir monthly inflow is rather important for the security of long-term reservoir operation and water resource management. The main goal of the present research is to develop forecasting models for the reservoir monthly inflow. In this paper, artificial neural networks (ANN) and support vector machine (SVM) are two basic heuristic forecasting methods, and genetic algorithm (GA) is employed to choose the parameters of the SVM. When forecasting the monthly inflow data series, both approaches are inclined to acquire relatively poor performances. Thus, based on the thought of refined prediction by model combination, a hybrid forecasting method involving a two-stage process is proposed to improve the forecast accuracy. In the hybrid method, the ANN and SVM are, first, respectively implemented to forecast the reservoir monthly inflow data. Then, the processed predictive values of both ANN and SVM are selected as the input variables of a newly-built ANN model for refined forecasting. Three models, ANN, SVM, and the hybrid method, are developed for the monthly inflow forecasting in Xinfengjiang reservoir with 71-year discharges from 1944 to 2014. The comparison of results reveal that three models have satisfactory performances in the Xinfengjiang reservoir monthly inflow prediction, and the hybrid method performs better than ANN and SVM in terms of five statistical indicators. Thus, the hybrid method is an efficient tool for the long-term operation and dispatching of Xinfengjiang reservoir.
The Chronic Condition of Life
Authors: Aitini E.
Published: August 2015

The young branches of the poplar trees moved lazily, wrapped in the pale blue spring, embraced by a soft breeze. [...]
Relationships between Patient Knowledge and the Severity of Side Effects, Daily Nutrient Intake, Psychological Status, and Performance Status in Lung Cancer Patients
Authors: Tian J. , Jia L.N. , Cheng Z.C.
Published: August 2015

Aim: We aimed to assess the relationships of patient education with the severity of treatment-induced side effects, daily calorie and protein intake, psychological status, and performance status in patients with lung cancer. Methods: The study patients were divided into an intervention (n = 62) and a control group (n = 110). The patients in the intervention group were provided with information about treatment, diet, and rehabilitation during chemotherapy. The patients in the control group were not specially provided with that information. Results: We observed significant differences between the intervention and control groups with respect to low daily protein intake (54.84% vs. 70.00%, p = 0.046), prevalence of depression (51.61% vs. 70.91%, p = 0.011), prevalence of severe side effects of treatment (14.52% vs. 37.27%, p = 0.002), and good performance status (75.81% vs. 55.45%, p = 0.008). Conclusions: Our results suggest that educating patients about cancer treatment and rehabilitation can lead to increased protein intake, a lower prevalence of depression, lesser side effects from cancer treatments, and improved performance status.
Unusual Presentation of Metastatic Sebaceous Crcinoma and Its Response to Chemotherapy: Is Genotyping a Right Answer for Guiding Chemotherapy in Rare Tumours?
Authors: Kumar V. , Xu Y.
Published: August 2015

Sebaceous carcinoma is a rare malignant tumour of skin. It commonly occurs in the head and neck region. The standard of care for localized disease is wide local excision followed by radiotherapy. Occasionally, sebaceous carcinoma can be associated with Muir–Torre syndrome, which is characterized by sebaceous lesions and carcinomas in the visceral organs. Metastatic sebaceous carcinoma is even rarer, with very little evidence about the role of chemotherapy in the treatment of metastatic disease. Here, we report a case of recurrent sebaceous carcinoma metastatic to the rectum (initially mimicking rectal cancer and Muir–Torre syndrome) in which the disease responded to multiple lines of chemotherapy. We also review the available literature on chemotherapy in this disease and discuss the role of tumour profiling and genotypeguided selection of chemotherapeutics in such rare tumours.
The Optimal Organization of Gynecologic Oncology Services: A Systematic Review
Authors: Fung-Kee-Fung M. , Kennedy E.B. , Biagi J. , Colgan T. , D’Souza D. , Elit L.M. , Hunter A. , Irish J. , McLeod R. , Rosen B.
Published: August 2015

Background: A system-level organizational guideline for gynecologic oncology was identified by a provincial cancer agency as a key priority based on input from stakeholders, data showing more limited availability of multidisciplinary or specialist care in lower-volume than in higher-volume hospitals in the relevant jurisdiction, and variable rates of staging for ovarian and endometrial cancer patients. Methods: A systematic review assessed the relationship of the organization of gynecologic oncology services with patient survival and surgical outcomes. The electronic databases medline and embase (ovid: 1996 through 9 January 2015) were searched using terms related to gynecologic malignancies combined with organization of services, patterns of care, and various facility and physician characteristics. Outcomes of interest included overall or disease-specific survival, short-term survival, adequate staging, and degree of cytoreduction or optimal cytoreduction (or both) for ovarian cancer patients by hospital or physician type, and rate of discrepancy in initial diagnoses and intraoperative consultation between non-specialist pathologists and gyne-oncology–specialist pathologists. Results: One systematic review and sixteen additional primary studies met the inclusion criteria. The evidence base as a whole was judged to be of lower quality; however, a trend toward improved outcomes with centralization of gynecologic oncology was found, particularly with respect to the gynecologic oncology care of patients with advanced-stage ovarian cancer. Conclusions: Improvements in outcomes with centralization of gynecologic oncology services can be attributed to a number of factors, including access to specialist care and multidisciplinary team management. Findings of this systematic review should be used with caution because of the limitations of the evidence base; however, an expert consensus process made it possible to create recommendations for implementation.
Eastern Canadian Gastrointestinal Cancer Consensus Conference 2014
Authors: Tsvetkova E. , Sud S. , Aucoin N. , Biagi J. , Burkes R. , Samson B. , Brule S. , Cripps C. , Colwell B. , Falkson C. , Dorreen M. , Goel R. , Halwani F. , Maroun J. , Michaud N. , Tehfe M. , Thirlwell M. , Vickers M. , Asmis T.
Published: August 2015

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Montreal, Quebec, 23–25 October 2014. Expert radiation, medical, and surgical oncologists and pathologists involved in the management of patients with gastrointestinal malignancies participated in presentations and discussions resulting in consensus statements on such hot topics as management of neuroendocrine tumours, advanced and metastatic pancreatic cancer, and metastatic colorectal cancer.
NEW ACTORS IN ARMED CONFLICTS
Authors: Fučík Jakub , Smekal Hubert
Published: August 2015

The article discusses the occurrence of a new group of actors in the field of pursuing military conflicts, namely the national courts. We present on the case of the Supreme Court of the State Israel that the process described as judicialization gained importance even in the issue of decision-making on pursuing military conflicts. We point out that in order to adequately grasp the position of the Supreme Court and its influence, it is necessary to consider also the acceptance of the Court's case-law from the side of other important actors in the political system of the State Israel.
Range extension of Myotis midastactus​ (Chiroptera, Vespertilionidae) to Paraguay
Authors: Moratelli Ricardo , Idárraga Liu , Wilson Don
Published: August 2015

Myotis midastactus Moratelli and Wilson, 2014 (Vespertilionidae, Myotinae) was described from the Myotis simus Thomas, 1901 complex based on collections from the Bolivian Savannah.

Four vouchers previously assigned to M. simus from the Alto Chaco in Paraguay (West of the Paraguay River) are reassigned here to M. midastactus. These specimens extend the geographic distribution of M. midastactus 1200 km southward, and constitute the first evidence of the species in the country. Based on other material from the Brazilian Pantanal and Cerrado, Central Paraguay and north-eastern Argentina, we also discuss the identity of simus-like populations south of the Amazon Basin. The status of these populations is still unclear, but the little evidence we have at hand indicates that these populations may represent another taxon—M. guaycuru Proença, 1943; whereas M. simus seems to be restricted to the Amazon basin. This hypothesis is still very speculative and requires further investigation. With the assignment of material from Alto Chaco to M. midastactus, seven species of Myotis are confirmed for Paraguay: M. albescens, M. lavali, M. levis, M. midastactus, M. nigricans, M. riparius, and M. ruber.
Determinants of willingness to eat insects in the USA and India
Authors: Ruby M.B. , Rozin P. , Chan C.
Published: August 2015

One of the major, if not the major impediment to large scale increases of human insect consumption, is the strong rejection of insects as food by most of the world’s population. In an effort to understand this aversion, we surveyed online samples of adults living in the USA and India to participate in a study on ‘attitudes toward food’. A substantial proportion of both Americans (72%) and Indians (74%) were at least willing to consider eating some form of insect food. Men were more willing to try eating insects than were women, especially in the USA. Disgust seems to be the most common reaction of both groups at the prospect of eating insects. The most common perceived benefits of eating insects were related to nutrition and environmental sustainability, and the most common risks related to risk of disease and illness. Both groups find ants the most palatable of a set of seven possible insects, and cockroaches the most unpalatable. In both samples, participants were most amenable to eating low levels of insect flour in a favourite food, and most averse to consuming whole insects. The best predictors of insect acceptance were disgust at the thought of eating insects, beliefs about the benefits of eating insects, sensation seeking, and the enjoyment of telling others about consumption of unusual foods.
La capellanía colativa del hospital municipal de Villena. Una capellanía del siglo XX.
Authors: Gandía Hernández Eleuterio
Published: August 2015

En el trabajo se describe y analiza la escritura de fundación y el expediente de tramitación de la capellanía colativa fundada en 1900 en la Parroquia de Santiago de Villena pero servidera en el hospital municipal de esta ciudad. Esta capellanía facilitó que las Siervas de Jesús se hicieran cargo de la asistencia hospitalaria e implicó la colaboración del Ayuntamiento de la ciudad.
Iglesia y representaciones de clase en Argentina a mediados del siglo XX. Una aproximación desde la cultura clasista jocista
Authors: Blanco Jessica
Published: August 2015

La propuesta de este trabajo es el análisis de las diversas representaciones de clase y dinámicas de relación entre la Juventud Obrera Católica (JOC) argentina y la jerarquía eclesiástica; en relación con miembros de otras organizaciones laicales y en el interior de la asociación, entre asesores eclesiásticos y jocistas.
Parto de la hipótesis que, hacia mediados del siglo XX, las profundas diferencias sociales que caracterizaban la sociedad argentina fueron reproducidas y naturalizadas por la Iglesia, tanto por eclesiásticos como por los laicos. Lo anterior adquiere particular implicancia para el funcionamiento de una asociación autodenominada obrera como la JOC, si va unido a una identificación del trabajador manual como un ser sospechoso y con capacidades de comprensión limitadas. De todas maneras, estas visiones de inferioridad intelectual y social, aceptadas acríticamente por los jocistas, coexistían con autorrepresentaciones de superioridad moral respecto a élites cuestionadas por su egoísmo e hipocresía, lo que contribuyó a profundizar los contrastes de clase y las distancias sociales en el interior de la Iglesia.
Comparison of Crack-Width Prediction Models for Steel-Reinforced Concrete Structures
Authors: Tran Huu , Li Chun Qing , Setunge Sujeeva
Published: August 2015

Prediction of time-to-cracking and crack-width of concrete cover provides useful information for decision making on maintenance and rehabilitation of reinforced concrete structures. Comparison of prediction models for time-to-cracking has been done in a recently published study, which indicated simple prediction models provide better good fit to various sets of experimental data than complex models. As a follow-up, this study uses published crack-width data to compare different models, developed in the literature to predict crack-width of concrete cover.
Asymptotic Self-Similar Solution of the Creep Crack Problems in Damaged Materials under Mixed Mode Loading
Authors: Stepanova Larisa , Yakovleva Ekaterina , Mironova Ekaterina
Published: August 2015

The creep crack problem in damaged materials under mixed mode loading is considered. The class of the self-similar solutions to the plane creep crack problems in a damaged medium under mixed-mode loading is given. With the similarity variable and the self-similar representation of the solution for a power-law creeping material and the power-law damage evolution equation the near crack-tip stresses, creep strain rates and continuity distributions for plane stress conditions are obtained. The self-similar solutions are based on the hypothesis of the existence of the completely damaged zone near the crack tip. It is shown that the asymptotical analysis of the near crack-tip fields gives rise to the nonlinear eigenvalue problems. The technique permitting to find the eigenvalues numerically is proposed and numerical solutions of the nonlinear eigenvalue problems arising from the mixed-mode crack problems in a power-law medium under plane stress conditions are obtained. Using the approach the eigenvalues different from the eigenvalues corresponding to the Hutchinson-Rice-Rosengren (HRR) problem are found. Having obtained the eigenspectra and eigensolutions the geometry of the completely damaged zone in the vicinity of the crack tip can be found for all values of the mixity parameter.
A Creep Damage Model for Rock Mass Based on Internal Variable Theory
Authors: Liu Yao Ru , Zhang Long , Yang Qiang
Published: August 2015

The creep damage is discussed within Rice thermodynamic theory with internal state variable (ISV). A viscoelastic-viscoplastic model with damage is derived by giving the complementary energy density function and kinetic equations of ISVs. The viscoelastic equation covers classical component model, and three creep phases with hardening and damage effect can be described by this model. The model parameter cabibration is conducted through uniaxial creep test of analogue material by loading and unloading method. Then intrinsic thermodynamic properties in three creep stages are indicated. The thermodynamic state of material system tends to equilibrate without damage and depart from equilibrate with damage.
Recent Advances in Simulating Failure Evolution with the Material Point Method
Authors: Chen Zhen , Zhang Xiong
Published: August 2015

To predict a complete process of failure evolution, discontinuous bifurcation analysis has been performed to link elastoplasticity and damage models with decohesion models. To simulate multi-phase interactions involving failure evolution, the Material Point Method (MPM) has been developed to discretize localized large deformations and the transition from continuous to discontinuous failure modes. In a recent study for the Sandia National Laboratories (SNL) challenge, the decohesion modeling is improved by making the failure mode adjustable and by replacing the critical normal and tangential decohesion strengths with the tensile and shear peak strengths, in order to predict the cracking path in a complex configuration with the least computational cost,. It is found that there is a transition between different failure modes along the cracking path, which depends on the stress distribution around the path due to the nonlocal nature of failure evolution. Representative examples will be used to demonstrate the recent advances in simulating failure evolution with the MPM.
Failure Surface Variation Obtained with the Truss-Like Discrete Element Method
Authors: Schumacher da Silva Guilherme , Goulart Fernandes Fabrício , Bordin Colpo Angélica , Puglia Vicente B. , Kosteski Luis E.
Published: August 2015

This paper presents the study of failure surface obtained in the truss-like Discrete Element Method (DEM). The element constitutive law considers the fracture energy of the material and its spatial variation is used to take into account the heterogeneity of the simulated materials. It is studied the influence of spatial distribution of fracture energy and the spatial lattice perturbation on the DEM failure surface. A DEM failure criterion is compared with concrete and rock failure.
Impact Failure Analysis of RC Beam Using ASPH Method Based on Damage Theory
Authors: Sonoda Yoshimi
Published: August 2015

The aim of this paper is to propose the impact failure analysis of reinforced concrete beam using tensile softening technique based on the damage mechanics. In general, tensile crack is the most dominant factor for concrete and it is not appropriate to evaluate their effect by theory of plasticity. Thus mechanical failure of concrete is considered by not only conventional plastic theory but also damage mechanics. In the analysis to calculate the plastic deformation, Drucker-Prager yield surface model is employed, on the other hand Von-Mises yield surface model is applied for the reinforcing bar. Besides, mechanical influence of tensile crack in the concrete is also considered as the decrease of effective cross-section area using anisotropic damage variable. Several impact tests of RC beam are reviewed and their impact response are simulated by proposed analysis method. As a result, it is confirmed that proposed method can simulate impact response of RC beam and it could predict precise failure condition such as the distribution of concrete crack using anisotropic damage model.
Nonlocal Continuum Damage Mechanics Approach of a Discrete Axial Chain under Non-Uniform Axial Load
Authors: Herisson Benjamin , Picandet Vincent , Challamel Noël , Perrot Arnaud
Published: August 2015

The failure of a discrete elastic-damage axial system is investigated using both a discrete and anequivalent continuum approach. The discrete damage mechanics (DDM) approach is based on amicrostructured model composed of a series of periodic elastic-damage springs (axial DDM latticesystem). Such a damage discrete system can be associated with the finite difference formulation of aContinuum Damage Mechanics (CDM) evolution problem.The nonlocal CDM models considered in this paper are mainly built from a continualizationprocedure applied to centered finite difference schemes. A comparison of the discrete and thecontinuous problems for the chains shows the effectiveness of the new micromechanics-basednonlocal Continuum Damage modeling, especially for capturing scale effects.
Modeling of Stress-State-Dependent Damage and Failure of Ductile Metals
Authors: Brünig Michael , Brenner Daniel , Gerke Steffen
Published: August 2015

The paper discusses an anisotropic continuum damage model. It takes into account the effect of stress state on damage and failure conditions as well as on evolution equations of damage strains. To validate the proposed framework experiments with biaxially loaded specimens and corresponding numerical simulations are performed covering a wide range of stress states. In addition, scanning electron microscope images of the fracture surfaces show different fracture modes corresponding to stress states revealed by numerical analyses.
Influence of Residual Stresses on the Damage of Composite Laminates under Tensile Loading
Authors: Wen Zhong Meng , Gong Xiao Lu
Published: August 2015

This work investigates the effect of residual stresses on the damage of composite laminate. The incremental hole-drilling method is applied to determine residual stresses in composite laminates [02/θ2]s and then acoustic emission technique is used for the identification of damage appearance during the tensile testing. The samples with different residual stress distribution are prepared through curing and post curing in order to study the role of residual stress on the damage of composite laminates. Besides the experimental method, the theoretical approach is applied to illustrate the role of residual stress on the damage of composite laminates.
Effect of Crack Closure Parameter and Negative Triaxiality on Damage Growth in Upsetting Problem
Authors: Kumar Manoj , Dixit P.M.
Published: August 2015

A Continuum Damage Mechanics model, that incorporates a crack closure parameter and a cut-off on negative triaxiality, is employed to simulate the damage growth in upsetting problem using the finite element package ABAQUS. Parametric studies are carried out to find the effect of the crack closure parameter and the cut-off. It is shown that the correct location of the maximum damage in upsetting problem (i.e., the location reported in the experimental literature) is predicted only if these parameters are incorporated.
A Study on the Microstructure of Welded Structural Steel Members at High Temperature
Authors: Cho Bum Yean , Kim Heung Youl , Yang Seung Cho , Chae Seung Un
Published: August 2015

This research is to show the microstructure of fracture parts of structural steels by welding at the high temperature. Discontinuity of mechanical and chemical property at HAZ of welding parts is the cause of decreasing structure safety. Therefore, this study was determined the effect of the welding of steels through a high temperature tensile tests and fracture portion of the microstructure. The results showed that does not cause destruction until temperature reached 600°C.
Influence of the Stress State on the Predictability of the Failure Probability in the Beremin Model
Authors: Golisch Georg , Münstermann Sebastian , Bleck Wolfgang
Published: August 2015

The influence of the local state of stress on the predictability of the Beremin model is investigated. For this purpose, the Beremin model is used on a series of tensile experiments with varying constraints. One specimen series is used to calibrate the Beremin parameters. These are afterwards applied to all specimen series. For all series the test results are compared to the predicted 5% to 95% failure probability corridor calculated by the Beremin model. The results are then discussed in concern of the influence of the stress state on the predictability of the Beremin model.
FE Analysis of Flexural Behavior of Externally Bonded CFRP Reinforced Timber Beams
Authors: Khelifa Mourad , Thi Van Diem
Published: August 2015

This study focuses on the flexural behavior of timber beams externally reinforced using Carbon Fibre Reinforced Plastics (CFRP). A non-linear finite element analysis is proposed in order to complete the experimental analysis of the flexural behavior of the beams. An elasto-plastic behavior is assumed for reinforced Timber and interface elements are used to model the interaction between CFRP and timber.The predicted and measured load–midspan deflection response results in addition to the failure modes are compared. It was observed that the predicted FE results are in good agreement with the experimental measured test data.
Comparison of Conventional Mechanical Testing with Innovative Techniques for Determination of Mechanical Properties of Nuclear Power Plant Components Materials
Authors: Štefan Jan , Kopřiva Radim , Eliášová Ivana , Siegl Jan
Published: August 2015

Within the nuclear power plant operational life management, components lifetime extension requires information on structural material degradation. Innovative testing methods of Small punch testing and Automated ball indentation test are based on the determination of material properties from sub-sized specimens. Present paper is focused on the employment of these techniques in the NPP irradiated materials testing and evaluation at the accredited hot cell testing laboratory of ÚJV Řež, a. s., Mechanical testing department. Comparison with the testing results from the conventional methods is depicted.
Strain-Based Continuum Damage Mechanics Model for Predicting FLC of AA5754 under Warm Forming Conditions
Authors: Mohamed Mohamed , Shi Zhusheng , Lin Jian Guo , Dean Trevor , Dear John
Published: August 2015

This paper presents a novel strain-based continuum damage mechanics (CDM) model for predicting forming limit curve (FLC) of AA5754 under warm forming conditions. The model is formulated and calibrated based on two different sets of experimental data; isothermal uniaxial tensile data at temperature range of 20-300°C and strain rate range of 0.001-10 s-1and isothermal FLC data at temperatures range of 20-300°C and forming speeds of 20-300 mm s-1. A good agreement has been achieved between the experimental and numerical results.
On the Failure Mechanisms in Reactor Pressure Vessel with Austenitic Cladding
Authors: Štefan Jan , Siegl Jan , Kytka Miloš , Brumovský Milan
Published: August 2015

The austenitic cladding of the WWER pressure vessel is made from two different layers with different fracture toughness values. Based on the fractographic analysis of the tested specimens in the initial, as well as in the irradiated conditions, it was found that individual failure micromechanisms take place during the crack propagation. The obtained results were used to find the relationship between the failure micromechanism changes and the fracture toughness values, as well as to assess the effect of neutron irradiation on the failure micromechanisms.
Elastoplastic and Damage Analysis of Trusses Subjected to Cyclic Loading
Authors: Šumarac Dragoslav , Perović Zoran
Published: August 2015

In the present paper, the Preisach model of hysteresis is extended to structural analysis of trusses damaged under cyclic loading in plastic range. Parameters for the Preisach model of cyclic plasticity are obtained from uniaxial loading experiment. Damage, as a consequence of micro cracks appearance due to alternating loading in plastic domain, is modeled using brittle elements according to Preisach procedure. Results of this research are compared with the already existing in the literature. In the paper examples of trusses under various cyclic loadings are presented.
Elastostatic Fields of an Embedded Circular Rigid Nano/Micro-Fiber with Interfacial Damage in Anti-Plane Couple Stress Elasticity
Authors: Hashemian Behdad , Shodja H.M. , Goodarzi Azadeh
Published: August 2015

It is well-known that classical continuum theory has certain deficiencies in predicting the nanoscopic behavior of materials in the vicinity of defects. Couple stress theory is one of the higher order continuum theories which can overcome such difficulties by introducing new characteristic length. An accurate analytical determination of the elastic fields of an embedded circular nano/micro-rigid fiber with damaged interface under remote anti-plane loading in the context of couple stress elasticity is of particular interest.
Analysis of Casting Materials under Thermal Fatigue
Authors: Altenbach Holm , Laengler Frank , Naumenko Konstantin , Ievdokymov Mykola
Published: August 2015

High-temperature components, for example turbochargers, are often subject to complex thermal and mechanical loading paths. Non-uniform temperature distribution and constraints by neighboring components result in complex timely varying stress and strain states during operation. In this paper the inelastic behavior of a casting material Ni-resist D-5S in a wide stress, strain rate and temperature ranges is analyzed. The material model including a constitutive equation for the inelastic strain rate tensor, a non-linear kinematic hardening rule and a damage evolution equation is developed. To calibrate the model, experimental databases from creep and low cycle fatigue (LCF) tests are applied. For the verification of the model, simulations of the material behavior under uni-axial thermo-mechanical fatigue (TMF) loading conditions are performed. The results for the stress response and lifetime are compared with experimental data.
Fabrication of Fiber Cement Using Tobacco Stalk Pulp from Agricultural Residue
Authors: Wasanapiarnpong Thanakorn , Nilpairach Siriphan , Siraleartmukul Krisana , Charoenvai Orakanya , Aungatichart Ornpiya , Laoharungpisit Nattapat
Published: August 2015

The objective of this research is to study the feasibility of using fiber obtained from tobacco stalk as reinforcement fiber in the production of fiber cement through hydrothermal methods. The fiber cement samples are made of the mixtures of 50% of ASTM Type I ordinary Portland cement, 35% of milled sand, 10% of calcium carbonate powder and 5% of cellulose fiber (eucalyptus pulp and tobacco stalk pulp). This study include the morphological characterization of the fibers and the study of effects that the use of fiber has on the fiber cement suspensions and on the mechanical and physical properties of the final product. The flexural strength of fiber cement samples using tobacco stalk pulp after curing in an autoclave at 180 °C for 4 hours is 14.21 MPa which is slightly lower than that of the samples using eucalyptus pulp at 17.10 MPa. However, the results obtained in the tests confirmed the high potential of the tobacco stalk as a source of fiber for the fabrication of a fiber cement capable of meeting the requirements of demanding applications.
Properties of Sintered Brick Containing Lignite Bottom Ash Substitutions
Authors: Auechalitanukul Chiraporn , McCuiston Ryan C. , Prasartseree Tarit , Pungpipat Pongpat , Olaranont Smatcha
Published: August 2015

This study examined the feasibility of utilizing lignite bottom ash as a partial substitute for ball clay in an insulating brick composition. Lignite bottom ash is a waste byproduct that is high in alumina and silicates and is therefore a candidate material for replacing aluminosilicate minerals such as clay. The lignite bottom ash powder was obtained from the Mae Moh power plant, Thailand. Small brick specimens were produced by die pressing a mixture of lignite bottom ash, ball clay and aluminum hydroxide. The composition of the mixture contained a fixed amount of aluminum hydroxide, while the lignite bottom ash replaced from 30 to 70% of the ball clay. The pressed samples were sintered at 1300 oC for 1 hour in air. The density, porosity, strength and thermal properties of the samples were measured. A microstructural analysis of the sintered brick was also performed. It was found that the porosity of the samples increased from 35 to 45% with increased lignite bottom ash content. The modulus of rupture and the thermal conductivity of the bricks were reduced with increased lignite bottom ash content, likely due to the increased amount of porosity. Dilatometric analysis found that the thermal expansion increased with increased amounts of lignite bottom ash, possibly as a result of an increased amount of glassy phase. Despite the high thermal expansion coefficient at high temperature, the feasibility of using lignite bottom ash in the insulating brick composition was demonstrated.
Physical and Mechanical Characterizations of Oxidized Regenerated Cellulose/Polycaprolactone Composite for Use as a Synthetic Dura Mater
Authors: Theeranattapong Thunyanun , Luangwattanawilai Ticomporn , Suwanprateeb Jintamai , Suvannapruk Waraporn , Chumnanvej Sorayouth , Hemstapat Warinkarn
Published: August 2015

An inadequate dural closure is one of the most challenging problems for neurosurgeons during the surgical procedures. A repair of the dura mater by natural or synthetic materials is often needed. This should satisfy fundamental criteria for example preventing cerebrospinal fluid leakage, exhibiting similar mechanical properties to the natural dura mater and not inducing foreign body reaction or inflammation. Oxidized regenerated cellulose (ORC) and polycaprolactone (PCL) have been extensively used as hemostatic agent and implant in many biomedical applications due to their long term proven safety, biodegradability and biocompatibility. This study investigated the potential of using a combination of ORC and PCL as a novel dural substitute. ORC/PCL composites were prepared by solution infiltration of ORC sheet with PCL solution (Mw ≈ 80,000) at various concentrations ranging 10-50 g/100 ml. Characterizations including density, tensile properties and microstructure were then performed. It was found that the density of all formulations did not differ and were in the range of 0.5-0.6 kg m-3. Microstructure of the samples typically comprised a bilayer structure having a PCL layer on one side and the ORC/PCL mixed layer on another side. Tensile modulus and strength initially decreased with increasing PCL concentration for up to 20% and re-increased again with further increasing PCL concentration. Elongation at break of all formulations was not significantly different. Both physical and mechanical properties of the samples were found to be similar to those of natural human dura mater.
The Effect of Heat Treatment on Fe2+/Fe3+ Ratio in Soda-Lime Silicate Glass
Authors: Meechoowas Ekarat , Poosrisoma Suwipa , Jampeerung Parida , Jitwatcharakomol Tepiwan
Published: August 2015

The redox reaction of a tableware soda-lime silicate glass contained with 0.04 - 1.00 wt% of iron oxide is investigated by UV-Vis spectroscopy. The quality and purity of raw materials, especially sand is required to control the amount of iron oxide as low as possible. Normally tableware glass contains small amount of iron oxide (0.01 - 0.04 wt%) and iron effect (green color) is controlled by adding decolorizing agent. The heat treatment around transition temperature is another method to decolorize iron by redox reaction control. It is believed that the reaction of iron oxide Fe2+(green) « Fe3+(yellow) still occurs in annealing process. In this study, the glasses were prepared by melting in the platinum crucibles. After annealing, they are cut into four pieces and heated at 550 560 570 and 580°C with different times. The results of the transmittance showed no significantly change but the color in CIE L*a*b* system of glasses heat treated at 550 and 560 °C slightly change into whiter shade. According to the result of calculated Fe2+/Fe3+ratio, the ratio of these glasses were decreased by 5 and 2.5 % respectively. On the contrary, the redox ratio of glass heated at 580 °C increased, due to Fe3+to Fe2+and the color changed into green. The results proved the kinetic of the redox reaction of Fe2O3and the possibility to use annealing process as another tool to control flint color of glass.
Preparation of Co/SiO2-Al2O3 Fiber Catalyst by Electrospinning for Fischer-Tropsch Synthesis
Authors: Prasongthum Natthawan , Reubroycharoen Prasert
Published: August 2015

The SiO2-Al2O3 fiber composites had been successfully prepared by the combination technique of electrospinning and sol-gel method. The effects of Al2O3 contents (1, 2, 3, 4 and 5%wt) on fiber diameter and morphology were investigated by SEM. It was observed that alumina content significantly influenced the average diameter of fiber which increased by increasing the alumina content. The prepared fiber composites were used as a support for cobalt (Co)-based catalysts for Fischer–Tropsch synthesis (FTS). The FTS performances over the fiber and porous catalysts were carried out in a fixed bed reactor at 280°C, 1 atm, and H2/CO of 2. The results showed that the fiber catalysts were easily reduced when comparing the porous catalyst. The fiber catalysts showed the activity at the same level of the porous catalyst, but their advantage was the lower water gas shift reaction which produced less CO2 than the porous catalyst. The CO conversion was 59.62% with the fiber catalyst and 52.80% with the porous catalyst under the same experimental condition. The fiber catalyst gave the maximum methane selectivity of 96.08% compared to the porous catalyst (85.63%).
Electrochemical Fabrication of Cu2O Photocathode for Photoelectrochemical Hydrogen Evolution Reaction
Authors: Thongthep Pattranit , Moonmangmee Somporn , Ponchio Chatchai
Published: August 2015

In this study, we can fabricate Cu2O on F-doped SnO2coated glass (FTO) substrates as photocathode for hydrogen evolution reaction by electro-deposition techniques. Cyclic voltammetry as a new deposition method was studied to fabricate Cu2O photocathode in a mixed solution of Cu (NO3)2and KNO3under a condition of low temperature and without pH value adjustment. Amperometry as a previous method was used to compare for Cu2O electrode fabrication under the situation of pH adjustment and higher temperature condition. A photocurrent from hydrogen evolution reaction was performed by keep potential at-0.2 V in 0.1 M Na2SO4under visible irradiation comparing with both fabricated method. The Cu2O photocathode from cyclic voltammetry deposition method presents photoelectrocatalytic activity higher than that of amperometry deposition method with the optimum conditions. This electro-deposition technique represents the excellent method with simple, fast and low cost of Cu2O photocathode fabrication for photoelectrochemical hydrogen evolution reaction.
LPG Synthesis from Syngas over Cu/ZnO-Pd-β Catalysts Prepared by Ultrasonic Spray Pyrolysis
Authors: Chaiwatyothin Sudarat , Ratanathavorn Wittawat , Vitidsant Tharapong , Reubroycharoen Prasert
Published: August 2015

Synthesis of nanoCu/ZnO catalyst for LPG production was prepared by ultrasonic spray pyrolysis (USP). Hollow spherical particles were obtained by USP technique using an aqueous solution of Cu (NO3)3.6H2O and Zn (NO3)3.3H2O with different concentration of 0.05, 0.1 and 0.5 molar under the pyrolysis temperatures of 600, 700 and 800°C. Mists of the solution were generated from the precursor solution by ultra sonic vibrators at frequency of ~1.7 MHz. The physicochemical properties of catalysts were characterized by X-ray diffraction, temperature-programmed reduction, scanning electron microscope, nitrogen adsorption-desorption, and energy dispersive X-ray spectrometer. The results showed that increasing in precursor concentration resulted in a large particle and particles size distributed in a range of 0.63-1.21 μm. Particles prepared at pyrolysis temperature 700°C exhibited homogeneous in size and shape compared to other temperature. The catalytic activity of nanoCu/ZnO-Pd-β catalysts was performed in a fixed-bed reactor for synthesizing LPG. The reaction took place at 260°C, 3.0 MPa, and the ratio of H2/CO = 2/1. All the products from the reactor were in gaseous state, and analyzed by on-line gas chromatography. The results showed that %CO conversion was high but decreased rapidly with increasing reaction time. Cu/ZnO catalyst prepared by co-precipitation gave higher %CO conversion than that prepared by ultrasonic spray pyrolysis. Moreover, hydrocarbon product distribution for Cu/ZnO catalyst produced at concentration 0.1 M 700°C by ultrasonic spray pyrolysis gave the highest LPG selectivity.
Gas-Sensing Properties of Pt-V2O5 Thin Films for Ethanol Detection
Authors: Kruefu Viruntachar , Pookmanee Pusit , Wisitsoraat Anurat , Phanichphant Sukon
Published: August 2015

In the present work, vanadium pentoxide (V2O5) nanoparticles have been investigated for monitoring ethanol (C2H5OH) at ppm levels in air. A one-step flame spray pyrolysis (FSP) process has been applied for the synthesis of vanadium pentoxide (V2O5) and platinum-loaded vanadium pentoxide (Pt-V2O5) nanoparticles. The samples have been studied to characterize their morphological and microstructural properties by X-ray diffraction and transmission electron microscopy. Pt addition to V2O5 samples were verified by energy dispersive X-ray spectrometry mode. The specific surface area of the nanoparticles was measured by nitrogen adsorption method. The application of the produced nanoparticles as sensitive and selective ethanol resistive sensor has been demonstrated. The Pt-loaded V2O5 sensor has shown higher response towards ethanol at ppm-level concentrations compared to unloaded one.
Material Safety and Integrity of Water-Filled Low-Density Polyethylene Bags in an Accelerated Weathering Investigation for Applications in Solar Water Disinfection (SODIS)
Authors: Terdthaichairat Weerawat , Techapiesancharoenkij Ratchatee , Laobuthee Apirat , Danwittayakul Supamas , Sukkasi Sittha
Published: August 2015

In this work, the potential use of LDPE bags as containers in the SODIS application by simulated in an accelerated weathering tester (QUV), with respect to material safety and durability, was investigated. For the material integrity, a decrease in the elongation at break from 818% (at the beginning) to 21% (after 6 weeks of UV exposure) corresponded to the long UV exposure. A significant degree of mechanical degradation was evident during 2 to 4 weeks of UV exposure. The UV-Vis results showed that the UV transmittance of the bags, mostly in the UV-B region, decreased with longer duration of UV exposure. The FT-IR results showed a slight increase in carbonyl group, particularly observable in the bags exposed under UV for 3 weeks or longer. For the material safety, the amount of plastic additives that were leached into water was negligibily small and much lower than the limit of the safety standard. The results and analyses from this work provide insights into the feasibility of LDPE as an alternative material for SODIS containers and potentially be useful for future designs of SODIS containers to improve the disinfection and durability performances.
Pomelo (Citrus maxima) Peel-Inspired Property for Development of Eco-Friendly Loose-Fill Foam
Authors: Looyrach Jarawee , Methacanon Pawadee , Gamonpilas Chaiwut , Lekpittaya Porntip , Lertworasirikul Amornrat
Published: August 2015

For development of eco-friendly packaging foam from pomelo peel, physical and mechanical properties of the pomelo peel and effects of pomelo varieties, namely Kao-Nampueng, Thong-Dee, and Kao-Pan, on their properties were investigated. It was found that the pomelo variety showed somewhat significant effect on physical and mechanical of pomelo peel properties. Because of its thick peel with high moisture content (75-80%) and water activity (0.90-0.98), the peel weight accounted for almost half of the total fruit weight. Cell structure and pore size of the peel were examined using the environmental scanning electron microscope (ESEM). The result showed an open cell foam structure with pore size of approximately 151±31 µm. The pore size was more open and large towards the outer surface. Uniaxial compression tests on pomelo peel samples with and without flavedo showed good reproducible stress-strain curves despite its biological variation. Young’s moduli of both samples were calculated to be 200-300 kPa and 110-210 kPa, respectively. Moreover, the most important property of packaging foam is the ability to absorb energy during impact which can be characterised through the measurement of the onset strain of densification. It was found that the strain values at the maximum energy absorption efficiency (εcd) of peel samples with and without flavedo for all studied pomelo varieties were comparable and were approximately in the range of 60-65%. These preliminary results indicate very promising mechanical properties of pomelo peel as eco-friendly packaging foam although further modifications are required to improve their physical and shelf-stability properties.
Preparation and Characterization of Polymer Blends from Nang noi srisaket 1 Silk Fibroin, Gelatin and Chitosan Nanofiber Mats Using Formic Acid Solution
Authors: Siridamrong Pornpen , Swasdison Somporn , Thamrongananskul Niyom
Published: August 2015

Silk fibroin, gelatin, and chitosan blended solution in formic acid with different composition ratios were electrospun. The fiber could be produced from SF:G : C blended solution at weight blending ratios (%wt: %wt: ml) of 10:20:0, 10:20:0.5, 10:20;1, 10:20:1.5, 10:20:2, and 20:10:1. When the chitosan content in blended solution increased, the average diameter decreased from 245 to 100 nm and fiber size distribution was narrow. The SF: G: C solution at ratio of 10:20:1 under high electric field and long spinning distance provided the continuous and uniform fibers. The formic acid as solvent did not affect to the electrospinnability and morphology of SF: G: C blended nanofiber. Tensile strength of SF: G: C (10:20:1) blended nanofiber was decreased with increasing of silk fibroin content, SF: G: C (20:10:1). The results indicated that SF: G: C electrospun nanofiber mats could be prepared and have a potential to be applied in membrane application.