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This article presents a new model developed to investigate hyperviscoelastic behavior of elastomeric materials/polyolefin elastomers (HDPE/POE blend) under dynamic biaxial and uniaxial tensile loading. Various strain energy functions (SEF) have been used in this model, and their capability to predict hyperelastic behavior of the aforementioned materials was validated by experimental data. In the experimental part, a new dynamic tensile-loading mechanism was designed and developed to be mounted on a drop-weight impact-testing machine. As a novelty, this mechanism has the ability to perform either uniaxial or biaxial dynamic tensile tests for any type of material, especially for investigating the hyperviscoelastic behavior of materials like elastomers at various strain rates. In addition, a new hyperviscoelastic model has been developed for elastomeric material, which can predict the behavior of the material well at different strain rates. By increasing the strain rate in the dynamic biaxial and uniaxial loading, Pucci–Saccomandi and Yeoh SEF predicted the dynamic behavior of material well due to its lower root mean square error. In fact, in this case, these functions are more capable than Mooney–Rivlin, Neo-Hookean, and polynomial SEF in predicting the effect of the strain rates. In addition, the results show that Yeoh SEF performs much better than the other SEFs in predicting the material behavior in cases of dynamic biaxial and uniaxial tensile strain. The results also indicated that the newly designed mechanism was capable of performing dynamic tensile loading and extracting its accurate results and could reduce the cost of testing compared to other methods. [ABSTRACT FROM AUTHOR]

An understanding of host selection by parasitoids can help in evaluating alternative host candidates to make conservation biological control of a target pest more reliable. This study investigated the host selection behaviour of Dolichogenidae tasmanica (Hymenoptera: Braconidae) in response to two related tortricid host species (Lepidoptera). The light brown apple moth, Epiphyas postvittana is the biological control target in Australian vineyards, while Merophyas divulsana was selected to evaluate its potential as an alternative host. We quantified the effects of host species, ages and experiences on the landing preferences of the parasitoid in dual choice tests. The effects of these host species on developmental time, sex ratio and body size of adult parasitoids were also examined. During all observations, D. tasmanica exhibited no statistically significant preferences in response to these hosts. Host species did not affect the body size of the wasp, but did influence its developmental time, possibly due to a trade-off between body size and developmental time of the wasp, which took longer in the smaller host, M. divulsana. The sex ratio was similar within host instars and between host species. These results suggest that M. divulsana should be a promising alternative host to support the local parasitoid population in vineyards as part of a conservation biological control programme that targets E. postvittana. [ABSTRACT FROM AUTHOR]

There are numerous old arch bridges in Iran that have been used as railway bridges for more than 70 years. Field load testing of old railway bridges in km-23 and km-24 of Tehran–Qom railway have revealed important characteristics of the bridges and have proven that there is still a large capacity under service load. Since most of these bridges are not designed for earthquake excitation, seismic vulnerability of these structures is uncertain. This fact necessitates the investigation of the earthquake resistance of these kinds of bridges. In this paper, seismic performance of bridges is assessed by the pushover analysis. These bridges are plain concrete arch structures with different span length and mechanical properties which have been built 70 years ago. The results of dynamic load tests are used to calibrate a finite element model of the bridges in which a plain strain analysis is carried out. Using non-linear static analysis method, suggested by several modern standards, the capacity curves of the structures and non-linear demand spectrum are obtained. The choice of control nodes in the pushover analysis and their influences on seismic performance of plain concrete arch bridges are investigated. The crown, centre of mass and a virtual point are selected as control nodes and it is demonstrated that the capacity curves are almost identical in all control node cases. Finally, the demand levels of the bridges are determined and compared with capacity curves. The results show that the earthquake resistance of these kinds of bridges totally depends on material properties and geometry of the structures. [ABSTRACT FROM AUTHOR]

This study reports experimental and numerical behaviors of both dry and silicon-coated twill-weave Kevlar fabrics under low-velocity impact. Initially, the fabrics are augmented in silicon aqueous suspension with various particle concentrations, and then, increase in the weight and friction coefficient are studied. The low-velocity impact test results show that the best particle concentration to meet the mentioned requirements is about 10 wt%. The experiments indicate high-impact resistance of the target by increase in the number of fabric plies. It is found that silicon-coated fabrics under drop-weight test show more time duration of impact and better performance than dry fabrics. Furthermore, the tests show that in the dry fabrics, broader region stretches due to impact, while in silicon-coated fabrics, the damage is limited to the impact point. The numerical simulation is performed for the coated fabric, and the effect of fabric augmentation with silicon is introduced as yarn friction. The numerical results are in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

Abstract: This study offers novel progresses for a semianalytical method to simulate 2D propagation of cracks based on linear elastic fracture mechanics. For this purpose, a new algorithm is proposed on the basis of the linear elastic fracture mechanics for crack propagation in single‐mode and mixed mode. Herein, discretization is only performed on the boundaries of the problem by using specific subparametric elements and higher‐order Chebyshev polynomials as mapping functions. Implementing the weighted residual method and by taking Clenshaw‐Curtis numerical quadrature, diagonal Euler's differential equations are obtained. Consequently, once the local coordinate origin is assumed at the tip of the crack, the stress intensity factors can be derived directly. In accordance with the rate of maximum energy release as a propagation criterion and by proposing a new quasi‐automatic remeshing procedure based on domain division, the crack propagation is applied here. Based on the new presented algorithm, application of the new semianalytical method to crack propagation analysis is more flexible and efficient. By taking this advantage, relatively coarse and simple discretization compared with other computational methods may be used. By modelling 4 benchmark problems with a few numbers of degrees of freedom, the validity and accuracy of the current method is illustrated. Results show that the presented algorithm is applicable for efficient and precise prediction of crack trajectories. [ABSTRACT FROM AUTHOR]

Rhythmic activities such as swimming stroke in the human body are learnable through conscious trainings. Inspiringly, the main objective of this study is to develop a control framework to reproduce the described functionality in the imitating robots. To do so, a two layer supervisory controller is proposed. The high-level controller, which acts as the conscious controller during trainings, is a supervisory dynamic-based controller and uses all system sensory data to generate stable rhythmic movements. On the other hand, the low-level controller in this structure is a distributed trajectory-based controller network. Each node in this network is an oscillatory dynamical system which has the ability to learn and reproduce the desired trajectory. Also, each node has a critic agent which evaluates the control eligibility of the low-level controllers for controlling the system. Then, based on the evaluation, these agents decide to assign the control of the system to the high-level controller or the low-level controllers. By using this structure, the system controller will act as simple and computing efficient as trajectory-based controllers and will perform as stably and robustly as dynamic-based controllers. At last, the applicability of this framework is demonstrated on a fully actuated robot and on an under-actuated biped robot. [ABSTRACT FROM AUTHOR]

In Iran, applying geostatistics to regional analysis is said to be in its early stages. The fundamental principle of this technique emphasizes the interpolation of hydrological variables in physiographical, instead of geographical, spaces. This paper deals with the adaptation, application, and comparison of two regional analysis methods based on geostatistics. In this study, data from 38 gauging stations located in the north of Iran were used to investigate the performance of geostatistical methods in two physiographical spaces. Two multivariate analysis methods, namely, Canonical Correlation Analysis (CCA) and Principal Components Analysis (PCA), were used to identify physiographical spaces. Gaussian and exponential models were selected as the best theoretical variogram models in CCA and PCA spaces, respectively. Ordinary and simple kriging geostatistical estimators were also used for regional estimations in both physiographical spaces. Using the interpolation methods in CCA and PCA spaces, regional flood estimations were made for different return periods (10, 20, 50, and 100 years). Finally, performance of both models was studied using five statistical indices. The results showed that both methods had similar and satisfactory performance; however, regional estimations in CCA had higher accuracy and less uncertainty than those in PCA-space. Furthermore, the results indicated that the ordinary kriging method had better performance than the simple kriging method in both spaces and the best interpolation efficiency was observed in the CCA space. [ABSTRACT FROM AUTHOR]

SUMMARY Objective To outline the Guy's and St Thomas' NHS Foundation Trust ( GSTFT) and Evelina London Children's Hospital ( ELCH) demand management plan for human albumin solution ( HAS) and usage. Background There is no UK-wide guidance governing the use of HAS. A severe shortage in 2015 prompted a Trust demand management programme. Indications were categorised according to locally agreed colour code and ASFA categories. Methods Following the implementation of the demand management programme, a 6-month audit of HAS usage was completed. Results A total of 1303.1 L of HAS was used in 1139 infusions; 737 infusions were 20% HAS, accounting for 175.7 L (13.5%) in 181 patients. Indications for 20% HAS were red in 53.9% (94.7 L), blue in 26.5% (46.5 L) and grey in 19.6% (34.5 L). The remaining 1127.4 L (86.5%) infused were of 4.5 and 5 % HAS. A total of 1102.3 L (97.8%) was used for plasma exchange, 941.4 L (85.4%) ASFA category I, 93.7 L (8.5%) category II, 25.5 L (2.3%) category IV and 41.7 L (3.8%) for indications not specified according to ASFA; 25.1 L (2.2%) were used for a grey indication (volume resuscitation for hypovolaemia). Conclusions The demand management programme provides surveillance of indications and retrospective verification of appropriate use. The majority of HAS indications were appropriate. Plasma exchange accounted for 84.6% of HAS usage and will be the focus of further demand management strategies. The demand management programme whilst aiming to promote best transfusion practice also ensures a tool to manage future shortages according to indication and available supply. [ABSTRACT FROM AUTHOR]

The existence of crack and notch is a considerable and serious subject in the failure study of solids and structures. As most of cracked domain problems do not have closed-form solutions, numerical methods are dominant approaches dealing with fracture mechanics problems. In fracture mechanics and failure analysis, cracked media energy and consequently stress intensity factors (SIFs) play a crucial and significant role. Based on linear elastic fracture mechanics, the SIFs may be estimated using the energy release rate, as an indirect approach. This study presents the development of a new semi-analytical method to model cracked media. In this method, only the boundaries of problems are discretized using specific higher-order subparametric elements and higher-order Chebyshev mapping functions. Implementing the weighted residual method and using Clenshaw-Curtis quadrature yield diagonal Euler's differential equations. Therefore, when the local coordinate origin is located at the crack tip, the geometry of crack problems is implemented directly without further processing. In order to present crack boundary conditions, a modified form of nodal force function is presented. Validity and accuracy of the proposed method is fully illustrated by four benchmark problems, whose results agree very well with those of other numerical and/or analytical solutions existing in the literature. [ABSTRACT FROM AUTHOR]

In this study, ballistic behavior of multi-layered ceramic armors under high velocity impact is studied numerically. The model consists of 2D-axisymmetric Lagrangian approach with Johnson–Holmquist constitutive model for alumina ceramic tiles, Mie–Gruneisen equation of state for polymeric interlayers, and Johnson–Cook constitutive relation for Armor Piercing (AP) projectile. The finite element results obtained from various armor layups show the potentiality of multi-layered ceramic armor in extending conoid fracture through the ceramic layers, thus leading to the increase in the armor performance. It is illustrated that besides ceramic armor layup, interlayers of ceramic tiles have a significant role in increasing the armor performance. Finally, the effect of different polymeric interlayers on ballistic performance of multi-layered ceramic armors against AP projectile is investigated. In order to measure the ballistic performance of the armors, various criteria are introduced. Depth of penetration of the projectile in the armor, residual velocity of the projectile, time duration in which the projectile is engaged inside the armor, projectile tip erosion during impact, and interaction volume ratio are some of these criteria. The study indicates that armor layup with thin front ceramic tiles backed by thicker tiles shows better conoid fracture extension and often better ballistic performance. Furthermore, among the polymeric interlayers used between the ceramic tiles, polystyrene causes the best and nylon causes the worst ballistic performance in the armor. [ABSTRACT FROM AUTHOR]

Background: Renal transplantation has long been considered the gold standard medical care for patients with end-stage renal disease. Candiduria continue to be a significant complication for renal transplant recipients. The risk of infections depends on the amount of immunosuppression and exposure to the potential pathogens. Objective: Molecular identification of Candida species isolated from renal transplant recipients with candiduria. Methods: Between 2009 and 2014, 62 Candida isolates were collected from 485 renal transplant recipients. All isolates were identified by PCR-RFLP profiles after digestion with the restriction enzyme MspI. Results: C. albicans (44%) and C. parapsilosis complex (5%) had the most and the least prevalence, respectively. Male to female ratio was 26/36, ranging in age from 19 to 62 years. Conclusion: Due to the fact that candiduria is connected with increased mortality in renal transplant recipients, precise identification of Candida species by molecular techniques can lead to an appropriate therapy among high risk patients. C. albicans remains the most prevalent species isolated from renal transplant recipients, Nevertheless, the number of non-C. albicans Candida species looks to be emerging. [ABSTRACT FROM AUTHOR]

This study presents a novel development of a new semi-analytical method with diagonal coefficient matrices to model crack issues. Accurate stress intensity factors based on linear elastic fracture mechanics are extracted directly from the semi-analytical method. In this method, only the boundaries of problems are discretized using specific subparametric elements and higher-order Chebyshev mapping functions. Implementing the weighted residual method and using Clenshaw-Curtis numerical integration result in diagonal Euler's differential equations. Consequently, when the local coordinates origin is located at the crack tip, the stress intensity factors can be determined directly without further processing. In order to present infinite stress at the crack tip, a new form of nodal force function is proposed. Validity and accuracy of the proposed method is fully demonstrated through four benchmark problems, which are successfully modeled using a few numbers of degrees of freedom. The numerical results agree very well with the analytical solution, experimental outcomes and the results from existing numerical methods available in the literature. [ABSTRACT FROM AUTHOR]

Open dumping is the common procedure for final disposal of municipal solid waste (MSW) in Iran. Several environmental pollution and soil degradation problems were found as a consequence of poor planning of landfills. So recognition of the MSW landfill state is required to prevent environmental problems. The objective of this research was to study the suitability of existing municipal landfill sites using geographic information system methods. Tonekabon city in the west area of Mazandaran province, northern Iran, along the southern coast of the Caspian Sea, was chosen as a case study. In order to carry out this evaluation, two guidelines were used: Minnesota Pollution Control Agency (MPCA) and regional screening guidelines. The results indicate that the landfills were not located in suitable sites and also that there are few suitable locations to install the landfills. [ABSTRACT FROM AUTHOR]

There has been some decline in the land potential capacity in many developing countries, and depending on location, the multi objective management strategy of Agroforestry can make effective use of natural resources to be feasible. Environmental principles which are effective on Agroforestry systems and their components, together with climatic factors, are the important parameters which been evaluated in this study. Two cities, Kazeroun (with warm climate) and Sepidan (with cold climate) in Fars province, were chosen for the purpose of this research, and after proper identification and classification of the Agroforestry systems, the effects of climatic factors were analyzed. Nineteen points were identified in these two cities by field investigations, with each type of Agroforestry systems and their corresponding components determined in each point. From the results, most of the systems in Kazeroun, characterized with warm climate, were Agrosilvopastoral, while Sepidan with a characteristic cold climate was the Agrosilvicultural system. Also, the components of each system clearly changed with change in climate, owing to the great importance of the livestock and crop components in Kazeroun and Sepidan, respectively. In general, it can be concluded that the impact of climatic factors on Agroforestry systems and their components has been approved in this study, and the results can be applied in developing these systems in other regions. [ABSTRACT FROM AUTHOR]

A special inverse analysis method is established in order to calibrate soil constitutive models. Taguchi method as a systematic sensitivity analysis is conducted to determine the real values of mechanical parameters. This technique was applied on the hardening soil (as an elastoplastic constitutive model) which is calibrated using the results from pressuremeter test performed on "Le Rheu" clayey sand. Meanwhile, a genetic algorithm (GA) as a well-known optimization technique is used to fit the computed numerical results and observed data of the soilmodel. This study indicates that the Taguchimethod can reasonably calibrate the soil parameters with minimum number of numerical analyses in comparison with GA which needs plenty of analyses. In addition, the contribution of each parameter on mechanical behavior of soil during the test can be determined through the Taguchi method. [ABSTRACT FROM AUTHOR]

Abstract: Back analysis as a modern observational method is a helpful technique for evaluation of soil and rock mass parameters and prediction of their mechanical behavior. Most back analysis techniques in geotechnical engineering problems are based on the methods that utilize the monitored data of stresses, strain and displacements. This technique is one of the prominent processes in design and evaluation of the stability of caverns that reveals the shortcoming of supports design and in fact is essential for evaluation of design parameters. Siah Bisheh pumped storage project with complex geometry, changeable geological formations and diverse geotechnical properties of rocks, is under construction on the Chalus River at the north of Iran. The underground complex consists of three main caverns placed near each other. In this study displacement based direct back analysis using continuum and discontinuum numerical modeling were applied and geomechanical properties of rocks, stress ratio and joints parameters were identified and then calculated parameters were compared with the initial design parameters. Both continuum and discontinuum modeling results were in a good agreement with measured displacements which confirm the numerical modelings correctness and back analysis results. [Copyright &y& Elsevier]

Abstract: Periodic solutions and their existence are one of the most important subjects in dynamical systems. Fractional order systems like integer ones are no exception to this rule. have shown that a time-invariant fractional order system does not have any periodic solution. In this article, this claim has been investigated and it is shown that although in any finite interval of time the solutions do not show any periodic behavior, when the steady state responses of fractional order systems are considered, periodic orbits can be detected. [Copyright &y& Elsevier]

Abstract: The hot ductility of Fe–29Ni–17Co alloy was studied in both cast and wrought conditions by hot tensile tests over temperature range of 900–1250°C and at strain rates of 0.001–1s−1. Over the studied temperature range, the wrought alloy represented higher elongation and reduction in area as compared to the cast alloy. Dynamic recrystallization was found responsible for the higher hot ductility of the wrought alloy and the improvement of hot ductility of the cast alloy at high temperatures. At temperature range of 1000–1150°C the wrought alloy exhibited a hot ductility drop while a similar trough was not observed in case of the cast alloy. It was also found that at temperatures of 1150–1250°C the best hot ductility is achieved in both cases of cast and wrought alloy. The experimental data of flow stress were constitutively analyzed and the apparent activation energy of deformation was estimated to be 344kJ/mol. [Copyright &y& Elsevier]

The results of an experimental study on the cyclic axial loading and unloading behaviors of thin-walled GFRP cylindrical shells are presented. Each specimen was tested first under pure axial compression until the first visible damage occurred, At that point, loading stopped and the unloading step started until the load returned to zero. Based on the results, it seems that for cyclic loading, using stiffened shells is better than using unstiffened shells. On the other hand, the damage growth in the stiffened shells is slower than in the unstiffened shells. For aerospace and aircraft structures, which have been using cyclic axial loading, it seems that composite structures with composite helical stiffeners are better than unstiffened composite structures. [ABSTRACT FROM PUBLISHER]

The results of an experimental study on the buckling behavior of thin-walled GFRP-stiffened cylindrical shells are presented. The buckling behavior of stiffened shells, with lozenge and triangular grids, and unstiffened shells were studied under quasi-static axial loading at room temperature. The effect of the number of helical ribs and grid shapes was thoroughly investigated. During the experimental study, local skin buckling mode was observed on all specimens. Based on the findings from this work, a minimum number of stiffeners should be present in a structure in order to play an effective role in its strength. Furthermore, it was concluded that under axial loading, increasing the number of helical ribs is more effective than adding hoop rings and changing the grid types. [ABSTRACT FROM AUTHOR]

Conventional methods for removing heavy metals from polluted waters, using chemical precipitation, sludge separation, chemical oxidation or reduction, and ion exchange, have been uneconomical and are weak processes. An alternative technique is the use of fungi as bioremediating agents. A strain of Trichoderma atroviride, isolated from a river passing through the metal polluted Serdang industrial area, was studied for its uptake and tolerance to Cu. This study found that the uptake capacity of T. atroviride for Cu ranged from 0.77 to 11 .20 mg/g in Potato Dextrose Broth in liquid media over the Cu concentration range of 25 to 300 mgIL. The isolate showed 50.3 to 85.4% adsorption and 9.6 to 47.1% absorption. These adsorption and absorption values are comparable to any good bioremediators for Cu found in the literature. This study suggests that T. atroviride is a potential bioremediator of Cu. However, further studies are still needed to confirm its practical use as a bioremediating agent under field conditions. [ABSTRACT FROM AUTHOR]

Abstract: Flexible job-shop scheduling problem (FJSP) is an extension of the classical job-shop scheduling problem. FJSP is NP-hard and mainly presents two difficulties. The first one is to assign each operation to a machine out of a set of capable machines, and the second one deals with sequencing the assigned operations on the machines. This paper proposes a parallel variable neighborhood search (PVNS) algorithm that solves the FJSP to minimize makespan time. Parallelization in this algorithm is based on the application of multiple independent searches increasing the exploration in the search space. The proposed PVNS uses various neighborhood structures which carry the responsibility of making changes in assignment and sequencing of operations for generating neighboring solutions. The results obtained from the computational study have shown that the proposed algorithm is a viable and effective approach for the FJSP. [Copyright &y& Elsevier]

Pre-eclampsia, as one of the most critical pregnancy complications, considered as a common cause of death in the prenatal period. The placental position had no significant association with pre-eclampsia, but there was a significant association between pre-eclampsia and placental thickness, and pre-eclampsia cases had a thicker placenta than normal group (P = 0.038). Placental thickness which is easily assessed at middle trimester of pregnancy by routine screening ultrasonography, could be an ideal predictive tool for evaluating the risk of developing pre-eclampsia. [Extracted from the article]

There is computer-supported learning and cooperative learning at universities. There are also a few 'virtual universities'. This paper links these three features in a way that reflects a vision of a future scenario for learners. The conclusions are based on the observation of the cooperative learning already taking place at Exeter University's Computer Science Department. [ABSTRACT FROM AUTHOR]

The article discusses the impact of wind erosion in the Sistan and Balouchestan region in Iran, and Afghanistan. It mentions that drought is one of the fundamentals factors that influence the creation of dust in the region, and one of the main factors of erosion. It notes that dust and sandstorms are natural phenomenon that induce damages to the economic and social infrastructure institutions.

Abstract: Background: In the past, the majority of renal transplantations in Iran were from living donors, but recently cadaveric donation of organs is increasing. We reviewed our experience on kidney transplantation from cadaveric donors for the past 5 years in our center. Methods: Between July 1998 and September 2004, 122 kidneys were removed from 61 cases of brain-dead patients and transplanted in 114 patients with end-stage renal disease in our center. Two kidneys had tumoral involvement and were discarded. Three kidneys were transplanted in other centers and three patients received en bloc kidney transplantations. In addition, we performed nine cases of heart, one case of liver, and one case of lung transplantations. All the recipients were followed for at least 1 year and posttreatment renal function and graft survival were determined. Results: All cadaveric donors were brain dead due to car (30%) and motocycle (70%) accidents, with ages ranging from 5 to 56 years (mean, 24/4 years). The mean warm and total cold ischemia times were 7 minutes and 8.1 hours, respectively. The mean distance between harvesting center and our hospital was 65 km. The 1-year graft survival was 92.3%, with mean serum creatinine of 1.76 ± 0.79 at 1 year. Of other transplanted organs, the liver and lung recipients died 24 hours and 45 days after operation. Among heart recipients, four are still alive. Conclusion: Cadaveric donors in developing countries including Iran can be excellent sources of organ donation. [Copyright &y& Elsevier]

In the railway network of Iran, a large number of masonry arch bridges exist which most of them was constructed 80 years ago. Despite these types of bridges have shown an appropriate behavior under the influence of gravity (vertical) loads, they have not been designed seismically. Concerning to the seismic hazard zoning map of Iran, most of these railway infrastructures are placed in the very high seismicity zones and constructed near the major faults. So the seismic assessment of these types of bridges has become a significant subject for the engineers to explain the failure and seismic performance levels of these structures. Thus, they can be rehabilitated or removed if it is found required. Among various methods for seismic estimation of the capacity of the structures under seismic loading, the non-linear dynamic method or the incremental dynamic analysis (IDA) may be mentioned as the most precise and complete method for near-field excitations. For this purpose, by selecting 28 near-field earthquake records, this study has seismically surveyed two railway masonry arch bridges, which are respectively placed in the kilometers 23 (2L20 bridge) and 24 (5L06 bridge) of the old railway of Tehran-Qom. The macro-modeling approach was used in the finite element method. In total, 316 non-linear dynamic analyses have been carried out for the seismic assessment of the masonry arch bridges under near-field ground motion. The results found from the IDA analysis specified that the near-field seismic performance of the masonry arch bridge with lower span length (i.e., 5L06 bridge) is safer than the bridge with longer span length (i.e., 2L20 bridge). Mostly, it has to decide to retrofit the masonry bridge with longer span length to improve their performance since the seismic behavior of those has been found inappropriate under near-field earthquakes. • FE simulation has performed to evaluated seismic response of masonry arch bridges • 316 incremental dynamic analysis (IDA) for near-field earthquakes has been conducted • The statistical analysis of the obtained results indicated that the arch bridges perfectly obey the Gamma distribution • IDA showed that the seismic behavior of these structures completely depends on their geometrical and mechanical features • The results show that the response of these infrastructures under near-field earthquakes is sensitive to velocity response [ABSTRACT FROM AUTHOR]

Proper combination of fiber reinforced composite and metal is a novel concept that it caused the advent of fiber‐metal laminates. This study reports the impact response of 3D‐woven glass fiber fabric composite cores experimentally, and it describes the effect of silica and graphene nanoparticles addition on energy absorption behavior of laminated fiber‐metal composites. The composites are manufactured by VARTM method with 71% fiber volume fraction. The low velocity impact tests are performed with drop‐weight impact test machine with various impact energies. The results show higher impact performance of plain‐weave samples compared with 3D‐woven glass fiber fabrics under different impact energies. The 3D‐woven glass fiber fabrics are preferred in case of using samples with lower weights. POLYM. COMPOS., 39:3528–3536, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

There is a large number of old arch bridges in Iran's railway network which the majority of them have been built more than 70 years ago. These structures, though displaying a good performance under the effect of service (gravity) loads but the seismic (lateral) loads have not been taken into account in their design; therefore, the seismic assessment of these structures is deemed necessary for obtaining their failure and seismic performance levels. So they can be strengthened or rendered out of order in case it is found necessary. There are numerous methods for evaluating the residual capacity of the structures under seismic excitation which among them the non-linear dynamic analysis or the incremental dynamic analysis (IDA) is the most accurate and perfect method. Selecting 22 far-field earthquake records, the present study investigated two plain concrete arch bridges which are located in kilometers 23 and 24 of the old Tehran-Qom railway, respectively. By using the finite element method and the macro-modeling method the km-23 and km-24 bridges were simulated and totally 231 non-linear dynamic analyses have been conducted. The results obtained from the incremental dynamic analysis indicated that the seismic behavior of the bridge with longer span length is more vulnerable (km-23) than the bridge with lower span length (km-24). Generally, the seismic performance of plain concrete arch bridges has been found inappropriate, therefore to improve their performance it is necessary to retrofit these type of structures. [ABSTRACT FROM AUTHOR]

This paper presents a new procedure for determining the fracture toughness of rock-like specimens using the diametric compression test with the center-cracked horseshoe disk (CCHD) method. Using finite element analysis, a dimensionless stress intensity factor was obtained and a formula was rendered for determining mode I fracture toughness. To evaluate the accuracy of the measurement results produced by the CCHD method, fracture toughness experiments were conducted on the same rock-like material using the notched Brazilian disk (NBD) method. The CCHD tests were simulated using a two-dimensional particle flow code for validation of the experimental results, and a great agreement between the pattern of crack initiation and propagation between the experimental and numerical simulations was observed. Lower values of fracture toughness were obtained from CCHD experiments than NBD tests due to purely tensile stress distribution at the tip of the existing notch in CCHD method. [ABSTRACT FROM AUTHOR]

One of the goals of the International Carbon Sequestration Project in South Khorasan Province is to study the sustainability of natural resources, especially in the rehabilitated areas, by reducing the reliance of villagers to the natural resources of the region, creating alternative livelihoods with job empowerment and solving the problems of villagers in the region, especially rural women. The purpose of this study was to predict the rural women' empowerment who received microcredits during the project. The research was done through a descriptivecorrelational method. Statistical sample includes 188 rural women who were members of the microcredit Fund. The validity of the questionnaire was confirmed by panel of research committee experts and the reliability was confirmed by calculating Cronbach's alpha coefficient to 0.95. The results of study showed that there is positively a significant correlation between rural women empowerment and variables of Membership Years, Loan Amount, and Loan adequacy, Age, Literacy Level and Income per month. But rural women empowerment could be predicted by three variables of Loan adequacy, Literacy Level and women Age. Also, Loan adequacy was known as the most powerful predictor of rural women empowerment. Given the positive impact of microcredits on rural women empowerment, as well as rural women empowerment to reduce pressure on ecosystems and improve carbon sequestration, it is proposed to increase the microcredit program and its amount. [ABSTRACT FROM AUTHOR]

This paper considers the problem of hybrid flowshop scheduling. First, we review the shortcoming of the available model in the literature. Then, four different mathematical models are developed in form of mixed integer linear programming models. A complete experiment is conducted to compare the models for performance based on the size and computational complexities. Besides the models, the paper proposes a novel hybrid particle swarm optimization algorithm equipped with an acceptance criterion and a local search heuristic. The features provide a fine balance of diversification and intensification capabilities for the algorithm. Using Taguchi method, the algorithm is fine tuned. Then, two numerical experiments are performed to evaluate the performance of the proposed algorithm with three particle swarm optimization algorithms available in the scheduling literature and one well-known iterated local search algorithm in the hybrid flowshop literature. All the results show the high performance of the proposed algorithm. [ABSTRACT FROM AUTHOR]

ABSTRACT Using derived dispersion relations, dielectric filters with embedded metamaterials are analyzed with the mode matching technique, and the results are applied to a Ka band SIW filter. This same filter is then compared to an identical filter in the absence of metamaterials to illustrate the effect on performance. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:443-446, 2014 [ABSTRACT FROM AUTHOR]

The aim of this paper is to study multi-objective flexible job shop scheduling problem (MOFJSP). Flexible job shop scheduling problem is a modified version of job shop scheduling problem (JSP) in which an operation is allowed to be processed by any machine from a given set of capable machines. The objectives that are considered in this study are makespan, critical machine work load, and total work load of machines. In the literature of the MOFJSP, since this problem is known as an NP-hard problem, most of the studies have developed metaheuristic algorithms to solve it. Most of them have integrated their objective functions and used an integrated single-objective metaheuristic algorithm though. In this study, two new version of multi-objective evolutionary algorithms including non-dominated sorting genetic algorithm and non-dominated ranking genetic algorithm are adapted for MOFJSP. These algorithms use new multi-objective Pareto-based modules instead of multi-criteria concepts to guide their process. Another contribution of this paper is introducing of famous metrics of the multi-objective evaluation to literature of the MOFJSP. A new measure is also proposed. Finally, through using numerous test problems, calculating a number of measures, performing different statistical tests, and plotting different types of figures, it is shown that proposed algorithms are at least as good as literature's algorithm. [ABSTRACT FROM AUTHOR]

Scheduling is a major issue faced every day in manufacturing systems as well as in the service industry, so it is essential to develop effective and efficient advanced manufacturing and scheduling technologies and approaches. Also, it can be said that bi-criteria scheduling problems are classified in two general categories respecting the approach used to solve the problem. In one category, the aim is to determine a schedule that minimizes a convex combination of two objectives and in the other category is to find a good approximation of the set of efficient solutions. The aim of this paper is to determine a schedule for hybrid flowshop problem that minimizes a convex combination of the makespan and total tardiness. For the optimization problem, a meta-heuristic procedure is proposed based on the simulated annealing/local search (SA/LS) along with some basic improvement procedures. The performance of the proposed algorithm, SA/LS, is compared with a genetic algorithm which had been presented in the literature for hybrid flowshop with the objective of minimizing a convex combination of the makespan and the number of tardy jobs. Several computational tests are used to evaluate the effectiveness and efficiency of the proposed algorithm against the other algorithm provided in the literature. From the results obtained, it can be seen that the proposed algorithm in comparison with the other algorithm is more effective and efficient. [ABSTRACT FROM AUTHOR]

A miniaturized Wilkinson power divider (WPD) using nonuniform transmission lines theory is presented in this letter. In the proposed design, we use nonuniform transmission lines instead of uniform transmission lines (UTLs) in each arm of WPD. The normalized width w(z)/h function of the NTLs which is expanded in a truncated Fourier series is used for optimization. A 500-MHz power divider is designed, fabricated and measured. The measurement results are in good agreement with the simulation results. The proposed divider's size has been reduced up to 52% in comparison with that of the conventional WPDs. [ABSTRACT FROM AUTHOR]

The utilization of renewable biomass as feedstock for biofuel production has been gaining prestige to mitigate carbon emissions. This paper aims to render an optimization model for designing a resilient and reliable biomass-to-biofuel supply chain network in which multi-modal terminals, biorefineries, and their connection link could be faced with disruption. For this purpose, risk-averse optimization, transitional probabilities, and spatial statistics models are employed. What is more, to overcome the repercussions of uncertain demand and the availability of raw materials, risk pooling and M/M/1 queuing system are considered. Finally, since the proposed model is an NP-hard problem, two meta-heuristic algorithms called improved ray optimization and colliding bodies optimization are employed to solve the proposed model. Computational results reveal that by increasing 20% of the conversion rate of biomass to biofuel, which leads to increase biomass supply, biofuel production increases by 20.88%, and the SC cost declines by 9.32% due to the better capacity distribution of bio-refineries. Also, the proposed model increases by 20.87% in the total SC costs under random disruptions than the risk-neutral model, although the failure costs of SC decline by 80.45%. Image 1 • Presenting a resilient and reliable biomass-to-biofuel supply chain. • Applying conditional-value-at-risk and absolute-semi deviation to reflect risk measure. • Considering the disruptions of two types of facilities and connecting link among them. • Considering risk-pooling and congestion to mitigate demand uncertainty and seasonality effect. • The proposed framework declines the failure costs of the supply chain by 80.45%. [ABSTRACT FROM AUTHOR]

In this work, we discuss the fundamental aspects of Electrohydrodynamic (EHD) conduction pumping of dielectric liquids. We build a mathematical model of conduction pumping that can be applied to all sizes, down to microsized pumps. In order to do this, we discuss the relevance of the Electrical Double Layer (EDL) that appears naturally on nonmetallic substrates. In the process, we identify a new dimensionless parameter related to the value of the zeta potential of the substrate-liquid pair, which quantifies the influence of these EDLs on the performance of the pump. This parameter also describes the transition from EHD conduction pumping to electro-osmosis. We also discuss in detail the two limiting working regimes in EHD conduction pumping: ohmic and saturation. We introduce a new dimensionless parameter, accounting for the electric field enhanced dissociation that, along with the conduction number, allows us to identify in which regime the pump operates. [ABSTRACT FROM AUTHOR]

Abstract: Successful outcomes in allopregnant women depend upon control of graft rejection mechanisms. An understanding of how the fetus escapes the maternal immune system may be relevant for the prevention of transplant rejection. It has been suggested that the same immunosuppressive cytokines contribute to successful pregnancy and transplantation. Recent reports suggest a role for transforming growth factor beta (TGF-β) in the generation of T-regulatory lymphocytes. In contrast, production of proinflammatory cytokines accompanying intrauterine infection has been associated with fetal rejection or preterm labor. Interleukin-12 (IL-12) is the unique stimulator for differentiation of T-helper lymphocytes (Th) to Th1 cells. It rapidly induces transcription of Th1 cytokines such as interferon-gamma. This study was performed in 70 pregnant women at 21 to 36 weeks gestation, and in 32 healthy nonpregnant controls. An indirect enzyme-linked immunosorbent assay was used to estimate TGF-β1, and IL-12 in serum. The results showed that TGF-β1 levels were higher in all pregnant women compared with the nonpregnant controls. No significant changes in serum levels of IL-12 were observed in pregnant compared with the normal control women. The results suggested that the cytokine milieu of the placenta appeared to play a critical role in the maternal acceptance of the fetus, and that TGF-β1 may function as a regulatory factor in fetal allograft survival during pregnancy. [Copyright &y& Elsevier]

Objective: an appropriate psychological intervention to promote the level of the public health and mental well-being of nurses has a great importance. This investigation was aimed to study the effectiveness of stress management training on the psychological welfare of nurses in Imam Khomeini Hospital. Methodology: this study was quasi-experimental with pretest-posttest that used a control group. Hence, 40 of the nurses in Imam Khomeini Hospital were selected by using a convenience sampling method and placed in the experimental group and the control group. Both groups were pretested by using psychological well-being 84-question scale. Afterwards, the experimental group was trained for ten sessions under stress management skill exercise, and the check group got no intervention. Next, both societies were post-tested, and the acquired data were analyzed by using inferential and descriptive statistical methods accompanied by SPSS 21 software. Findings: the results indicated that stress management training significantly led to the promotion of psychological well-being in nurses (p < 0.001). Conclusion: it was found from the research that due to the high level of effectiveness of stress management training, its low cost, and its high acceptability by the patients, especially when it was performed in a group, had a significant positive impact on the promotion of psychological well-being in nurses. [ABSTRACT FROM AUTHOR]