Search

The investigation of fatigue failure in polymeric materials subjected to cyclic loading holds significant importance across diverse engineering applications. Numerous variables influence material behavior, encompassing material-related factors such as composition, molecular weight, orientation, and additives, as well as external factors like applied stress magnitude (stress amplitude, dynamic stress frequency and mean stress), and operating temperature. This paper presents an experimental exploration into the impact of loading parameters—mean stress, stress amplitude, and dynamic stress frequency—on the failure modes of two thermoplastic materials: high-density polyethylene (HDPE) and polyvinyl chloride (PVC). The study begins with an assessment of the mechanical and physical properties of the materials, followed by the design and manufacturing of a specialized uniaxial fatigue test rig. Tensile–tensile fatigue tests incorporating positive mean stress are conducted, evaluating the influence of altering stress amplitude and frequency on fatigue life and failure mode. The outcomes reveal that HDPE primarily experiences thermal and creep failure modes, with a lack of observed fatigue failure. Conversely, PVC specimens manifest three distinct failure modes: ductile, creep, and fatigue, with the type of failure contingent upon loading parameters. These findings offer significant insights into the various fatigue failure modes and contribute to an enhanced comprehension of the intricate interplay between loading dynamics and failure modes in polymeric materials. [ABSTRACT FROM AUTHOR]

Most packaged food products are attacked and penetrated by insects. Causing reducing food quality. Since, different ways are investigated for controlling stored-product pests without application of chemical methods. So, the present study included laboratory methods to evaluate the effectiveness of two packaging materials, polyethylene and cellophane with silica nano particles to prevent or minimize the insect infestation and grain wastage resulting by the attack of wheat grain by confused flour beetle, Tribolium confusum. Studies made to determine the protecting capacity of the two packaging materials through assessing some parameters, number of adults infested poly ethelene and cellophane bags, percentage weight loss of grains, the results revealed that cellophane was the better packaging material than polyethelene, so polyethylene was the susceptible packaging material because it had maximum number of holes as a result penetrations by insects into them. Also, treatment the two types with packaging materials with different concentrations of nano silica protect the treated packaging materials from insect infestation and the protection increase with the increase of the concentration of silica nano particles [ABSTRACT FROM AUTHOR]

Background: Integrated pest management is one of the ways to solve the problems of increased outbreaks of pests induced by the effects of climate change. Therefore, the present investigation was carried out to study the integrated effect of entomopathogenic fungus, Metarhizium anisopliae and gamma radiation to control 5th instar larvae the black cut worm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), under laboratory condition. The leaf dipping technique was used to test the pathogenicity of different concentrations of the fungus against normal and F1 (resulted from irradiated male parent pupae with 100 Gy) larvae. As well as, the changes in the haemocytes were studied using LC50 of M. anisopliae of both treatment (unirradiated and F1 larvae). Results: The results showed that larval mortality percentage was both M. anisopliae virulent and time dependent. Furthermore, F1 larvae were more susceptible to M. anisopliae where 100% mortality was recorded after 3 days of M. anisopliae treatment at 8 × 105 spores/ml concentration. While mortality of normal (unirradiated) larvae reached 40% at the same time and concentration. The haematological examination of larvae revealed significant reduces in total haemocyte counts, differential percentage and increase in morphological malformation of the haemocytes which was pronounced by F1 + M. anisopliae LC50. Conclusions: According to the obtained results, the gamma irradiation increased the pathogenicity of the fungus against the 5th instar A. ipsilon larvae. So, the combination between the two control tools may provide a satisfactory integrated control program after further field trials. [ABSTRACT FROM AUTHOR]

Efficacy of Spintor® 24% SC (spinosad) and vinegar were studied to control Culex pipiens larvae by testing different concentrations of spinosad (10, 50, 100, 500 and 1000 µl/10 ml) or vinegar (125, 250, 500 and 750 µl/10 ml). The percentage mortality of larvae was increased by increasing concentrations and time. While 100%mortality was obtained at the concentration 1000 µl/10 ml of spinosad after 48 h, in the case of vinegar treatment 100 % mortality was obtained at the concentration of 750 µl/10 ml after 72 h. Both spinosad and vinegar exhibited a histological effect on the midgut by degeneration of the epithelial cells, the disintegration of the plasma and basement membranes and extensive disruption of the cellular microvillar. Generally, spinosad manifested a higher level of activity against Cu. pipiens larvae than vinegar. [ABSTRACT FROM AUTHOR]

Abstract Delays caused by congestion, faults and process variation (PV) degrade networks-on-chip (NoC) performance. A congestion aware, fault tolerant and process variation aware adaptive routing algorithm (CFPA) is introduced for congested and faulty asynchronous NoCs. The proposed routing algorithm maintains two routing tables to determine the packet path: one for routing directions based on propagation delay (including PV delay), and the other to keep track of the queuing delays at each router port. The queuing delay is used as an indication for congestion. The proposed routing tables store multiple paths to every destination via all polar directions, which makes CFPA a fault tolerant algorithm in case of path failures. The proposed algorithm is verified against other popular routing algorithms for NoCs with different topologies and network dimensions. On average, CFPA enhances the NoC throughput by 60% compared to the recently proposed routing algorithms. With CFPA , the impact of faults on NoC throughput is alleviated by 48%. In addition, the average delay of messages routed using CFPA is shorter than that of other algorithms by (26 ∼ 75)% under process variation conditions. Furthermore, the proposed algorithm minimizes the impact of PV on NoC throughput to less than 5% of the nominal throughput for mesh topology. Highlights • A new routing algorithm (called CFPA) for networks-on-chip is proposed. • CFPA is congestion-aware, process-variation-delay-aware and fault-tolerant. • CFPA provides significant improvement in throughput, delay and fault-tolerance. [ABSTRACT FROM AUTHOR]

Stepped beams are crucial power transmission components in many mechanical engineering systems. These beams may be dynamically analyzed using the stepped Timoshenko model or the rigid mass model. In this paper, a new set of fundamental solutions is derived in order to normalize the Timoshenko beam equation at the origin of the coordinates. This set of solutions is used to derive the frequency equation of both stepped and rigid mass models. The validity ranges of these models were investigated by comparing the modal frequency results of both models. In addition, selected cases were compared using mode shape analysis. Three different models with classical end conditions are considered through this work. These are free–free, pinned–pinned and clamped–free beam configurations. The numerical results of the current work show that increasing the intermediate diameter ratio and decreasing the length ratio of the rigid mass results in decreasing the percentage deviation between the rigid mass model results and the elastic model results. [ABSTRACT FROM AUTHOR]

Stresses reductions and/or raising the load-carrying capacity for a mechanical structure are always great dilemmas for researchers. In this article, a novel method is proposed, and its efficiency is examined for achieving these goals on functionally graded rotating nonuniform thickness discs. The originality of this method relies on comprising a geometrically well-defined area, into the whole structure, with certain homogeneous properties including density, thermal expansion coefficient, and elasticity matrix. This area acts as a reducer of the maximum values of various stress components. The solution of the magnetoelastic/magneto-thermoelastic problem is accomplished using the finite element method. The disc is subjected to partial uniform outer pressure, whereas, upon applying thermal loads; the thermal boundary conditions are considered symmetric. The proposed method is found to be beneficial as the obtained results demonstrated the ability to reduce the maximum stresses with different percentages depending on the location, angular width, and properties of the predefined area. This is reflected by an attainable decrease in the maximum compressive tangential stress and the von Mises stress by approximately 20.7% and 12.5%, respectively, under certain conditions. [ABSTRACT FROM AUTHOR]

A major drawback of First Order Stochastic Dominance approach is dominance indetermination. Levy and Leshno in 2002 suggested Almost Stochastic Dominance as a remedy in the uni-dimensional case. We introduce a Generalization of Almost First and second Order Dominance (MAFOD and MASOD) to the multidimensional case with application on child wellbeing in Egypt. We perform a multidimensional (FOD) analysis on seven deprivation indicators for three age-groups of children from Egypt 2014 Demographic and Health Survey (EDHS14). This methodology allows the ordinal ranking of regions and governorates of Egypt in terms of their children wellbeing based on their probability of domination. To solve the dominance indetermination we apply MAFOD and MASOD. [ABSTRACT FROM AUTHOR]

A major drawback of First Order Stochastic Dominance approach is dominance indetermination. Levy and Leshno in 2002 suggested Almost Stochastic Dominance as a remedy in the uni-dimensional case. We introduce a Generalization of Almost First and second Order Dominance (MAFOD and MASOD) to the multidimensional case with application on child wellbeing in Egypt. We perform a multidimensional (FOD) analysis on seven deprivation indicators for three age-groups of children from Egypt 2014 Demographic and Health Survey (EDHS14). This methodology allows the ordinal ranking of regions and governorates of Egypt in terms of their children wellbeing based on their probability of domination. To solve the dominance indetermination we apply MAFOD and MASOD. [ABSTRACT FROM AUTHOR]

Stresses reductions and/or raising the load-carrying capacity for a mechanical structure are always great dilemmas for researchers. In this article, a novel method is proposed, and its efficiency is examined for achieving these goals on functionally graded rotating nonuniform thickness discs. The originality of this method relies on comprising a geometrically well-defined area, into the whole structure, with certain homogeneous properties including density, thermal expansion coefficient, and elasticity matrix. This area acts as a reducer of the maximum values of various stress components. The solution of the magnetoelastic/magneto-thermoelastic problem is accomplished using the finite element method. The disc is subjected to partial uniform outer pressure, whereas, upon applying thermal loads; the thermal boundary conditions are considered symmetric. The proposed method is found to be beneficial as the obtained results demonstrated the ability to reduce the maximum stresses with different percentages depending on the location, angular width, and properties of the predefined area. This is reflected by an attainable decrease in the maximum compressive tangential stress and the von Mises stress by approximately 20.7% and 12.5%, respectively, under certain conditions. [ABSTRACT FROM AUTHOR]

Synchronous NoCs suffer from performance degradation due to clock skew. Clock skew is more pronounced with process variation (PV). Although asynchronous NoCs suffer from handshaking overhead, their immunity to PV is better than synchronous networks which would favor them in terms of throughput. Architecture-Level analysis aims to determine the ability of different NoC communication schemes to mitigate the impact of PV. The proposed analysis depends on redeveloped simulator which is unique PV-aware simulator for both synchronous and asynchronous NoCs. Architecture-Level simulation shows that clock skew causes significant performance degradation in synchronous networks. Clock skew represents 27% and 32% of the delay variation for 45 nm and 32 nm technologies, respectively. Using real traffic, Architecture-Level analysis shows considerable throughput reduction for synchronous NoC under PV conditions. Throughput degradation of synchronous NoC increases rapidly with technology scaling down. 64-Cores synchronous NoC loses 30% of the nominal throughput for 45 nm technology and 41% of throughput for 32 nm with PV. On the other hand, 64-Cores asynchronous network throughput degradation is 12% and 13.6% for 45 nm and 32 nm technologies, respectively. For different NoC dimensions and using different workloads, throughput reduction for synchronous design is more than double the reduction of asynchronous design. Asynchronous scheme is preferable as technology scales. [ABSTRACT FROM AUTHOR]

This study to estimate toxigenic diversity of three S. aureus strains (11SaUTI, 5SaRM and 21SaRW) isolated from clinical patient, food and water at Mesallata City, Libya. As well as to know antibiotic resistance, phage typing, biofilm formation and genoypes (icaA gene and 16s rDNA gene). Three S. aureus isolates were selected from isolates obtained from the different sources and identified by conventional biochemical tests and confirmed by VETIk kit. These isolates exhibited variation of toxigenic, antibiotics resistance, biofilm formation and phage plaque forming (phage typing). The amplified 16s rDNA gene to confirm the diversity of S. aureus isolates . In addition to molecular diagnosis to have a complete and clear image for bacterial etiology based on genetic variability. DNA genome of S. aureus isolates was used as template for PCR to amplify 16s rDNA gene. Partially, length of 16s rDNA gene could be synthesized using the internal primer sets combination in PCR to confirm its interspecific to S. aureus with an expected size 1219 bp. The replacement situation of nucleotide sequences were with percent of camera 1.067, 2.217 and 1.313 respectively. Three S. aureus isolates were recorded in gene bank under accession no. LC121093.1 (11SaUTI); LC121094.1 (5SaRM) and LC121095.1 (21SaRW). [ABSTRACT FROM AUTHOR]

This article describes a novel approach for the classification of modes of travel in mixed traffic intersections based on video data. The classification is semi-supervised where the selected classification features included road-user movements' characteristics such as speed, gait and cadence frequencies (for pedestrians and cyclists respectively) in addition to the estimate of the road-user occupied area. A modified version of the semi-supervised spectral clustering method is adapted where the selected labeled features identify possible relations; thereby enforcing certain constraints between features. Two case studies are demonstrated with video data collected at a roundabout in Vancouver, Canada and a U-turn crossover in Cairo, Egypt. Road- users were first detected and tracked using object recognition methods. The classification algorithm was then applied on the extracted objects trajectories to identify the corresponding modes of travel. Experiments were conducted on the two case studies along with a comparison to other related classification methods. A sensitivity analysis was undertaken to assess the impact of the constraints selection on the effectiveness of the method. A performance analysis demonstrated the robustness of the proposed classification method with an accuracy of higher than 87 percent achieved for both datasets. The experimental results showed that the method also outperformed other related classification methods. This research contributes to the literature of automated data collection and analysis of non-motorized traffic. [ABSTRACT FROM AUTHOR]

A new finite-element approach to calculating the hardness of nanocomposite materials based on a 316L stainless steel matrix and nanoceramic inclusions is presented. Two different ceramic inclusions, alumina and titania, are considered. The finite-element model is created on the basis of the spherical Brinell hardness contact model. A quarter of the 3D finite-element is used to model the contact between a spherical tungsten carbide indenter and nanocomposite materials. The effect of the elastic modulus and percentage of the ceramic inclusions on the hardness of the nanocomposites considered is investigated. The finite-element model is verified by comparing its results with experimental data. The comparison showed a good agreement for low-concentration compositions and a slight deviation for highly concentrated ones. [ABSTRACT FROM AUTHOR]

The goal of this research study is to examine, through the finite element method, the efficiency of using two-dimensional (2D) functionally graded materials (FGMs) in lowering the elastic/thermoelastic stresses acting on cylinders. In 2D-FGMs, the properties are assumed to vary in the radial and tangential directions simultaneously, which is rarely investigated in the literature. The cylinder is subjected to asymmetric inner normal traction with/without asymmetric thermal loading. For the considered case studies, results revealed that 2D-FGMs is beneficial compared to the conventional grading. In case of considering mechanical load only, the tangential stress declines by almost 39%. Similarly, accounting for thermomechanical load resulted in radical falls for the tangential and axial stresses by around 63% and 61%, respectively. Accordingly, the von Mises stress declines dramatically with different values allowing for safe load escalation, and enhancing the cylinder's durability. Finally, no certain values for the used tangential function's parameters are preferred to have maximum reduction of stresses under all working circumstances, which necessitates performing optimization. [ABSTRACT FROM AUTHOR]

The reliance on aggregate historical collision data as a sole technique in road safety analysis was proved challenging in the quest to better understand, predict, and improve road safety conditions. Therefore, surrogate safety measures such as the traffic conflict technique have been promoted as an alternative or complementary approach to assess and analyze road safety from a broader perspective than collision statistics alone. A primary focus of road safety analysis that could greatly benefit from vision-based road safety analysis is before-and-after (BA) evaluation of safety treatments. This study demonstrates the use of automated traffic conflict analysis in conducting a before-and-after (BA) safety study for an Adaptive Traffic Signal Control (ATSC) system. The objective of this study is to conduct a time-series (before-to-after) safety evaluation for two intersections in the City of Surrey where the ATSC system was implemented. The ATSC automatically makes real time adjustments to traffic signal timing based on actual observed traffic volumes to reduce vehicle delays and travel time. Overall, the study demonstrated the usefulness of using automated traffic conflicts in before-and-after safety evaluations of the ATSC system. Traffic conflicts occur more frequently than collisions so the desired sample size for analysis can be obtained in much shorter time periods. It was also demonstrated that the use of computer vision techniques to automate the extraction of traffic conflicts from video data can overcome the shortcomings of the traditional manual conflict observation methods. The results of the analysis showed considerable increase in the frequency and severity of conflicts following the implementation of the ATSC system. The increase of vehicle travel time following the implementation of the ATSC has likely contributed to the observed increase in conflict frequency and severity. [ABSTRACT FROM AUTHOR]

When the brittle heterogeneous material is simulated via lattice models, the quasi-static failure depends on the relative magnitudes of Telem, the characteristic releasing time of the internal forces of the broken elements and Tlattice, the characteristic relaxation time of the lattice, both of which are infinitesimal compared with Tload, the characteristic loading period. The load–unload (L–U) method is used for one extreme, Telem ≪ Tlattice, whereas the force–release (F–R) method is used for the other, Telem ≫ Tlattice. For cases between the above two extremes, we develop a new algorithm by combining the L–U and the F–R trial displacement fields to construct the new trial field. As a result, our algorithm includes both L–U and F–R failure characteristics, which allows us to observe the influence of the ratio of Telem to Tlattice by adjusting their contributions in the trial displacement field. Therefore, the material dependence of the snap-back instabilities is implemented by introducing one snap-back parameter γ. Although in principle catastrophic failures can hardly be predicted accurately without knowing all microstructural information, effects of γ can be captured by numerical simulations conducted on samples with exactly the same microstructure but different γs. Such a same-specimen-based study shows how the lattice behaves along with the changing ratio of the L–U and F–R components. [ABSTRACT FROM PUBLISHER]

Abstract: We present a variational multiscale constitutive model that accounts for intergranular failure in nanocrystalline fcc metals due to void growth and coalescence in the grain boundary region. Following previous work by the authors, a nanocrystalline material is modeled as a two-phase material consisting of a grain interior phase and a grain boundary affected zone (GBAZ). A crystal plasticity model that accounts for the transition from partial dislocation to full dislocation mediated plasticity is used for the grain interior. Isotropic porous plasticity model with further extension to account for failure due to the void coalescence was used for the GBAZ. The extended model contains all the deformation phases, i.e. elastic deformation, plastic deformation including deviatoric and volumetric plasticity (void growth) followed by damage initiation and evolution due to void coalescence. Parametric studies have been performed to assess the model's dependence on the different input parameters. The model is then validated against uniaxial loading experiments for different materials. Lastly we show the model's ability to predict the damage and fracture of a dog-bone shaped specimen as observed experimentally. [Copyright &y& Elsevier]

An In-Service Road Safety Audit (RSA) project was commissioned by the Ministry of Public Works (MPW) in Kuwait, which would be the first RSA to be completed in Kuwait. The project was intended to serve as a demonstration project, highlighting the concept and process of a road safety audit, in an attempt to illustrate the benefits of RSAs and how RSAs may improve the overall level of safety for the road users in Kuwait. For Kuwait's inaugural RSA Project, a roadway known as Kabd Road was selected. The roadway, which is perceived to be very dangerous and often referred to as the 'Death Road,' is located south of the metropolitan area of the City of Kuwait. Kabd Road was considered to be an excellent project to demonstrate the RSA concept since the roadway has some design features that adversely impact the safety performance. In addition, the road appeared to be poorly maintained at some locations, which also created some significant safety hazards for motorists using the roadway. Poor driver behavior of the motorists using Kabd Road would also a contributing factor to the dangerous conditions that exist on the roadway. This paper describes the demonstration project, including the process that was followed to implement an RSA in a region where RSA did not previously occur. The paper also provides some of the findings from the RSA. [ABSTRACT FROM AUTHOR]

Micro-voids of varying sizes exist in most metals and alloys. Both experiments and numerical studies have demonstrated the critical influence of initial void sizes on void growth. The classical Gurson-Tvergaard-Needleman model summarizes the influence of voids with a single parameter, namely the void-volume fraction, excluding any possible effects of the void-size distribution. We extend our newly proposed model including the multi-sized void (MSV) effect and the void-interaction effect for the capability of working for both moderate and high loading rate cases, where either rate dependence or microinertia becomes considerable or even dominant. Parametric studies showthat theMSVrelated competitive mechanism among void growth leads to the dependence of the void growth rate on void size, which directly influences the void's contribution to the total energy composition. We finally show that the stress- strain constitutive behavior is also affected by this MSV-related competitive mechanism. The stabilizing effect due to rate sensitivity and microinertia is emphasized. [ABSTRACT FROM AUTHOR]

An approach is presented to estimate corridor travel time in urban areas using available data of a nearby corridor. The purpose is to improve the efficiency of real-time traveller information systems when the number of data collection sensors is limited. Field travel time data were collected for two corridors in downtown Vancouver, British Columbia. The association between the travel times of the two corridors was found significant. Models were then developed to estimate travel times on one corridor using data of the other corridor. The developed models included regression, Artificial Neural Network (ANN), Neuro-fuzzy, and K-Nearest Neighbours (KNN). The estimation accuracy was considered satisfactory as the Mean Absolute Percentage Error (MAPE) of all models ranged between 13.7% and 17.6%. It was concluded that the concept of estimating travel time from nearby corridors is promising. The type of modelling technique had a little impact on the results with the KNN method producing slightly better results [ABSTRACT FROM AUTHOR]

General summaries on the load–unload and force–release methods indicate that the two methods are efficient for different-charactered quasi-static failures; therefore, it is important to choose the right one for different applications. Then we take, as an example, the case where the release of the ruptured element's internal force is infinitely slower than the relaxation of the lattice system and analyze why the force–release method works better than the load–unload method in this particular case. Different trial deformation fields are used by them to track the next equilibrium state. Force–release method ensures that the deformation throughout the whole failure process coincides exactly with the controlled-displacement boundary conditions and we utilize the ‘left modulus’ concept to prove that this method satisfies the energetic evolution in the force–displacement diagram; both of which are not satisfied by the load–unload method. To illustrate that the force–release method is not just another form of the load–unload method, a tensile test on a specifically designed system is analyzed to further compare the above two methods, showing that their predicted sequences of elemental failures can be different. In closing, we simulate the uniaxial tensile test on a beam lattice system by the load–unload and force–release methods and exploit the details of the resulting fracture processes. [ABSTRACT FROM PUBLISHER]

Traffic micro-simulation models are widely used to quantify the benefits and limitations of traffic control options. The usefulness of these models in making design and traffic control decisions will mainly depend on their accuracy and reliability. Accordingly, thorough and careful efforts are required in the development, calibration, and validation of these models. This paper describes a procedure for the calibration and validation of medium-sized simulation network models. Most calibration efforts of small scale networks in the existing literature focus only on driver behaviour and lane changing parameters. On the other hand, calibration of medium and large scale networks was directed to OD matrix estimation with little attention given to driver behaviour parameters calibration. The procedure used in this paper provides a comprehensive calibration of the micro-simulation model in a sequential manner. A case study was applied to a VISSIM model of downtown Vancouver, British Columbia, which is an urban condensed grid network of more than 100 signalized intersections. The calibration procedure included OD matrix estimation using recent traffic volumes, route choice calibration by manipulating link surcharges, and driver behaviour parameters calibration using an experimental design and multiple runs. Real-life travel time data were collected for model calibration and validation. The observed travel times were found to reasonably match simulation travel times of the calibrated model. Therefore, it was concluded that the model was calibrated and validated with an acceptable level of accuracy. [ABSTRACT FROM AUTHOR]

The importance of considering three-dimensional (3D) sight distance in geometric design has been demonstrated by several researchers. However, little progress has been made in the use of 3D analysis in the design of highways. This can be mainly attributed to the complexity of the computations required for 3D analysis. This paper presents a new algorithm for calculating the 3D sight distance. The algorithm is considered more efficient, less computationally intensive, and more flexible than previously developed approaches. The algorithm is based on a parametric representation of the roadway and roadside features without any implicit approximation of the roadway surface. The paper presents analysis results of various alignment configurations to demonstrate the use of the algorithm and to examine the influence of different geometric elements on the 3D sight distance. The paper also provides an analytical tool that can investigate and determine the conditions under which a 3D analysis is considered necessary. [ABSTRACT FROM AUTHOR]

Accident prediction models are invaluable tools that have many applications in road safety analysis. However, there are certain statistical issues related to accident modeling that either deserve further attention or have not been dealt with adequately in the road safety literature. This paper discusses and illustrates how to deal with two statistical issues related to modeling accidents using Poisson and negative binomial regression. The first issue is that of model building or deciding which explanatory variables to include in an accident prediction model. The study differentiates between applications for which it is advisable to avoid model over-fitting and other applications for which it is desirable to fit the model to the data as closely as possible. It then suggests procedures for developing parsimonious models, i.e., models that are not over-fitted, and best-fit models. The second issue discussed in the paper is that of outlier analysis. The study suggests a procedure for the identification and exclusion of extremely influential outliers from the development of Poisson and negative binomial regression models. The procedures suggested for model building and conducting outlier analysis are more straightforward to apply in the case of Poisson regression models because of an added complexity presented by the shape parameter of the negative binomial distribution. The paper, therefore, presents flowcharts detailing the application of the procedures when modeling is carried out using negative binomial regression. The described procedures are then applied in the development of negative binomial accident prediction models for the urban arterials of the cities of Vancouver and Richmond located in the province of British Columbia, Canada. [ABSTRACT FROM AUTHOR]

In British Columbia, many highways are located in mountainous terrain and the costs of highway construction in these areas are high. One method of controlling construction costs is narrow medians but the safety consequences of using narrow medians were never determined. Recent research on safety in geometric design has focused on establishing quantitative relationships between collisions and cross-sectional elements using collision prediction models (CPMs) and collision modification factors (CMFs). In some situations, such as the use of narrow medians, it is difficult to find CPMs and CMFs that adequately describe the design scenario. In other instances, it is difficult to measure the safety in terms of collision reduction because of a lack of data or difficulty isolating the impact of a single design element on collision frequency. In these situations, reliability analysis can be used to evaluate the risk associated with a particular design feature. Reliability analysis is not intended as an alternative to quantify safety using collision frequency but represents a complementary method of measuring safety in terms of risk. In this paper, reliability analysis was completed on a series of horizontal curves with varying horizontal sight distance restrictions and the probability of being unable to stop within the available sight distance was calculated. The results of the study found that narrow medians combined with tight horizontal curves did not provide sufficient sight distance that vehicles would be expected to stop if an object was in a vehicle’s path. The analysis was applied to a case study of two constrained alignments in mountainous terrain of British Columbia. [ABSTRACT FROM AUTHOR]

Reviews research works related to evaluating geometric design consistency of roads. Principles for evaluating consistency of road design; Definition of alignment indices; Examples of alignment indices; Predicted driver workload in terms of visual demand of drivers unfamiliar with road.

Accumulation of heavy metals in tissues of the crayfish Procambarus clarkii and in water were evaluated in areas located in the Egyptian Delta (Gharbiya, Kafr El-Shaikh, and Menofiya) in 2010 and 2021. Statistics showed that in 2010 the highest concentration of heavy metals in the digestive gland and in muscles was Zn, both in Gharbiya and Menofiya, while Fe was the highest accumulated in the digestive gland, and Pb was the highest in muscles of samples from Kafr El-Shaikh. The results showed that heavy metal loads decreased in Kafr El-Shaikh in 2021, whereas Fe increased significantly (p ⩽ 0.05) in Gharbiya and Menofiya (41.44 ± 2.32, 47.25 ± 2.64 μ g/g). Accumulation of Cd and Zn in gills and muscles decreased in all areas from 2010 to 2021, while a significant increase (p ⩽ 0.05) was shown in Fe and Cu in 2021. All heavy metals significantly decreased (p ⩽ 0.05) in waters of the studied areas from 2010 to 2021. Résumé: L'accumulation de métaux lourds dans les tissus de l'écrevisse Procambarus clarkii et dans l'eau a été évaluée dans des zones du delta du Nil (Gharbeya, Kafr el-Cheik, et Menufeya) en 2010 et 2021. Les statistiques ont montré que en 2010 la plus forte concentration en métaux lourds dans la glande digestive et les muscles était Zn, à la fois à Gharbeya et Menufeya, tandis que dans les échantillons de Kafr el-Cheik, Fe était le plus accumulé dans la glande digestive et Pb dans les muscles. Les résultats ont montré que les charges en métaux lourds décroissent à Kafr el-Cheik en 2021, tandis que Fe a augmenté significativement (P ⩽ 0 , 05) à Gharbeya et Menufeya (41,44 ± 2,32, 47,25 ± 2,64 μ g/g). L'accumulation de Cd et Zn dans les branchies et les muscles a décru dans toutes les zones de 2010 à 2021, alors qu'une augmentation significative (P ⩽ 0 , 05) a été trouvée pour Fe et Cu en 2021. Tous les métaux lourds ont décru significativement (P ⩽ 0 , 05) dans les eaux des zones étudiées de 2010 à 2021. [ABSTRACT FROM AUTHOR]

Egypt has many wild plants such as Sonchus oleraceus, Cichorium pumilum and Portulacaoleraceae which are one of the perfect sources of natural effective compounds including alkaloids, flavonoids, tannins, terpenes, steroids and phenols. This study investigated that P.oleracea has a greater total phenolic, flavonoids and antioxidant activity followed by S. oleraceus and finally C. pumilum. Also, alkaloid was found in all the plants examined with the highest quantities obtained in S. oleraceus (78.6%) then, P. oleracea (66.4%), while C. pumilum have 41.8%. While total terpenoid and saponin were the highest percentages with Portulaca oleracea (61.6%) and (35.3%) respectively. In addition to all the extracts could inhibit these fungi at a different level in which ethanolic and methanolic extracts of Portulaca oleracea and Cichorium pumilum generally had higher antifungal activities against A. aflatoxiformans and A ochraceus. Finally, these plant extracts contain many effective compounds that enable to play the role of antifungals. [ABSTRACT FROM AUTHOR]

The environmental temperature increased during summer and decreased during winter to the limits that might negatively affect animal and human reproduction. The responses of Egyptian rams to either hot or cold climatic conditions were studied in six mature rams subjected to weekly testicular Doppler ultrasonographic examination, blood sampling, seminal plasma collection and semen evaluation. The maximum environmental temperature and the relative humidity were used to classify the climatic condition according to the heat stress equation of sheep into hot months where temperature–humidity index (THI) was >26 (31.67 ± 0.54), and cold months where THI was <22 (18.39 ± 0.41). Testosterone, estradiol, superoxide dismutase (SOD), glutathione peroxidase (GPX) and lipid peroxide product (malondialdehyde, MDA) were measured in both blood and seminal plasma, while catalase (CAT) and reduced glutathione (GSH) were measured in blood and seminal plasma, respectively. Results revealed that, during the hot months, rams displayed significantly decreased testicular blood flow, increased seminal plasma MDA, decreased seminal plasma (SOD, GPx and GSH) and blood CAT antioxidant enzymes. The present study evidenced two novel findings: (a) the marked decrease in testicular blood flow volume, that is remarkable increase in both resistive index (RI) and pulsatility index (PI) values, during hot months could be negatively affected both seminal plasma enzymatic activities and seminal attributes, and (b) the SOD and GPx activities in seminal plasma of such animals were suitable predictive markers for seminal attribute evaluation. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the combined effect of lufenuron and gamma radiation against the cotton leaf worm. Full-grown pupae were irradiated with a substerilizing dose 100Gy, and the 4th instar larvae of the F1 were used in the experiments. The results revealed that the percent mortality was time- and concentration-dependent, and the F1 larvae were more susceptible to lufenuron than the normal larvae. The enzymatic analysis of phenoloxidase and acetylcholinesterase activities showed that the F1 larvae treated with LC50 of lufenuron exhibited the highest activity when compared to larvae treated with LC50 of lufenuron or F1 larvae. We conclude that a combination of gamma radiation and lufenuron could be an excellent integrated control program for Spodoptera littoralis. [ABSTRACT FROM AUTHOR]

Four new groups of 4-((2ʹ-substitutedphenylimino)methyl)phenyl-4"-alkoxy benzoates, Ina-d, of Schiff base ester liquid crystals, were prepared and investigated for their mesophase formation and stability. Each group constitutes four homologous series that differ from each other by the lateral attached polar group X in the ortho position for the imine mesogen at terminal benzene ring that alternatively changed from F, Br, NO2 and lateral benzene ring. Within each homologous series, the number (n) of carbons in the alkoxy chain varies between 6, 8, 10 and 12. Molecular structures of the prepared compounds were confirmed via elemental analysis, FT-IR, and 1H NMR spectroscopy. Mesomorphic properties were investigated by differential scanning calorimetry (DSC) and the phase identified by polarised light microscopy (PLM). A comparative study was made between the investigated compounds and their previously prepared laterally neat, 4-((4ʹ-phenylimino)methyl)phenyl-4"-alkoxy benzoates (IIn); the result revealed that all lateral substituents not only decrease the melting temperature but also the mesophase stability and shown only nematic phase. Density functional theory (DFT) calculations for new lateral derivatives were discussed. Nematic texture of 4-((2'-Bromophenylimino)methyloxy)phenyl-4"-decyloxy benzoate [ABSTRACT FROM AUTHOR]

The article offers information on the editorial policy implemented by the "Canadian Journal of Civil Engineering." The journal, which is intended to reflect and stimulate the practice of civil engineering in Canada, is said to be recognized as the official technical journal of the Canadian Society for Civil Engineering and is published monthly by the National Research Council. It is not claimed to publish papers that are clearly in the domain of the "Canadian Geotechnical Journal" or the "Canadian Surveyor."

Travel time is an important metric for both road users and transportation professionals. Collecting travel time in large road networks is costly and faces the challenge of partial network coverage resulting from an inadequate number of sensors (moving or fixed sensors). This study proposes a solution to the problem of limited network sensor coverage caused by insufficient coverage of probe vehicles or limited fixed sensors. The study uses travel time correlation and the concept of neighbor links to develop dynamic models that are capable of estimating real-time travel times on links not covered by sensors in Kuwait City. Neighbour links are a set of nearby links that have similar traffic characteristics, located in the same area type, and their travel times are correlated. The performance of the developed models is validated using field-measured and simulated travel time data on 70 links in Kuwait City. VISSIM microsimulation model is developed to investigate the impact of probes (moving sensors) penetration rate on travel time estimation accuracy and links Coverage. The results show that the dynamic model is feasible, applicable and provides a satisfactory accuracy even at low probe penetration rate of 1%. However, based on links coverage, a probe penetration rate of 3% is recommended. The average links coverage reached 86.1% at a penetration rate of 3%. This research can find applications in Advances Traveler Information Systems, traffic planning, signal design, and demand management. [ABSTRACT FROM AUTHOR]

The electronic properties of the pristine and tungsten-doped monoclinic niobium pentoxide (B–Nb 2 O 5 ) crystals have been investigated using density functional theory generalized gradient approximation (GGA) with the semi-localized Revised Perdew, Burke, and Ernzerhof (RPBE) functional. The use of RPBE allowed the accurate calculation of the band gap. The band gap of B–Nb 2 O 5 ( 3.45 eV) can be significantly reduced and tuned via W-doping down to 1.39 eV. The W 5d orbitals affected the position of conduction band minimum (CBM) with negligible effect on the valence band maximum (VBM). The calculated band gaps of the W–Nb 2 O 5 showed a bowing phenomenon, which was attributed to charge exchange as well as volume change. Moreover, the calculated band positions indicated staggered band gap characteristics of the W-doped Nb 2 O 5 . Furthermore, the calculated charge carrier concentration of highly doped Nb 2 O 5 , estimated by Boltzmann-like distribution, is close to that of Si, making the material of potential interest in solar energy conversion applications. Eventually, the optical dielectric function showed an increased electronic contribution of the dielectric constant associated with a metallic behavior of the W-doped Nb 2 O 5 at high W content, while the absorption spectrum and refractive index of the studied systems pointed out a red-shift and cladding behaviors, respectively. [ABSTRACT FROM AUTHOR]

Cysteine-functionalized chitosan magnetic nano-based particles were synthesized for the sorption of light and heavy rare earth (RE) metal ions (La(III), Nd(III) and Yb(III)). The structural, surface, and magnetic properties of nano-sized sorbent were investigated by elemental analysis, FTIR, XRD, TEM and VSM (vibrating sample magnetometry). Experimental data show that the pseudo second-order rate equation fits the kinetic profiles well, while sorption isotherms are described by the Langmuir model. Thermodynamic constants (G°, H°) demonstrate the spontaneous and endothermic nature of sorption. Yb(III) (heavy RE) was selectively sorbed while light RE metal ions La(III) and Nd(III) were concentrated/enriched in the solution. Cationic species RE(III) in aqueous solution can be adsorbed by the combination of chelating and anion-exchange mechanisms. The sorbent can be efficiently regenerated using acidified thiourea. [ABSTRACT FROM AUTHOR]

Abstract: In most metals and alloys, the evolution of voids has been generally recognized as the basic failure mechanism. Furthermore, stress triaxiality has been found to influence void growth dramatically. Besides strain intensity, it is understood to be the most important factor that controls the initiation of ductile fracture. We include sensitivity of stress triaxiality in a variational porous plasticity model, which was originally derived from hydrostatic expansion. Under loading conditions rather than hydrostatic deformation, we allow the critical pressure for voids to be exceeded so that the growth due to plasticity becomes dependent on the stress triaxiality. The limitations of the spherical void growth assumption are investigated. Our improved constitutive model is validated through good agreements with experimental data. Its capacity for reproducing realistic failure patterns is also indicated by a numerical simulation of a compact tensile (CT) test. [Copyright &y& Elsevier]

Treatment of chronic anal fissure (CAF) by fissurectomy with botulinum toxin A (BTA) injection results in a healing rate of greater than 90%. BTA injection, however, can cause incontinence and perianal sepsis. The decrease in sphincter pressure following topical treatment with 2% diltiazem cream (DTC) is comparable to that following BTA injection but with potentially fewer complications and at less cost. We report the shortterm results of a pilot study comparing fissurectomy with BTA and fissurectomy followed by DTC for the treatment of CAF. The recorded outcomes of CAF following treatment with the two methods were analysed retrospectively. Patients underwent either fissurectomy followed by injection of 40 U BTA into the internal sphincter (group A) or fissurectomy followed by the perianal application of DTC twice daily for 8 weeks (group B). Symptom resolution and treatment side effects at the initial follow-up were compared. Demographics, fissure characteristics and the number of multiparous women between the two groups were comparable. At a median follow-up of 12 weeks (range 8–20 weeks), the two groups had similar rates of complete symptom resolution (group A, 25/28, 89.3%; group B, 19/23, 82.6%; p=0.7739), with minor side effects. In this small pilot study fissurectomy combined with chemical sphincterotomy resulted in high short-term fissure healing rates. The study also suggested that fissurectomy followed by 8 weeks of topical DTC may be as good as fissurectomy with BTA injection in the treatment of CAF. A prospective study, adequately powered to determine the significance of differences is needed. [ABSTRACT FROM AUTHOR]

This study deals with investigation of selectivity of p-morpholino-methylcalix[4]arene appended silica from a group of metal ions having similar charge and radii. The values of distribution ratio revealed that modified silica possess higher selectivity for Cu2+. In addition, relative selectivity coefficients of modified silica were found to be 24.1, 13.8, 8.6 and 4.01 for Cu2+/Ni2+, Cu2+/Co2+, Cu2+/Cd2+, Cu2+/Pb2+, respectively. The maximum adsorption capacity was 1.5 mmolg−1. The reusability data suggested no any loss of adsorption capacity of this material up to 10 cycles. The developed material was also applied for determination of copper in lake water samples with satisfactory results. [ABSTRACT FROM AUTHOR]

The cryopreservation of immature oocytes would generate a readily available, non-seasonal source of female gametes for research and reproduction. In domestic animals, the most promising results on oocyte cryopreservation have been reported in cattle, few studies have been conducted on buffalo. The aim of the present study was to compare the use of different vitrification solutions and various cryodevices on viability and developmental competence of buffalo oocytes vitrified at the germinal vesicle (GV) stage. Cumulus oocyte-complexes (COCs) obtained at slaughterhouse from mature buffalo ovaries were randomly divided into three main groups and vitrified by using either straw or open pulled-straw (OPS) or solid surface vitrification (SSV) in a solution composed of either 20% ethylene glycol (EG) + 20% glycerol (GLY); VS1 or 20% EG + 20% dimethylsulfoxide (DMSO); VS2, respectively. Following vitrification and warming, viable COCs were matured in vitro for 22 h. Some COCs were denuded and stained with 1.0% aceto-orcein to evaluate nuclear maturation, whereas the others were fertilized and cultured in vitro for 7 days to determine the developmental competence. Although the recovery rate (64.9%) was the lowest in the oocytes vitrified by SSV using 20% EG + 20% DMSO as compared to the other groups, the best survival rate of the COCs was achieved in the same treatment (96.7%), which was significantly higher ( P < 0.05) than those vitrified using traditional straws (71.8% in VS1 and 73.6% in VS2) or those vitrified using OPS and VS1 (73.9%). Furthermore, in the nuclear maturation test, the highest maturation rate (75.5%) was achieved in SSV vitrified COCs using 20% EG + 20% DMSO (VS2), which was similar to the controls (77.1%). Post IVF and embryo culture, the highest cleavage and blastocyst development rates were obtained in COCs vitrified in 20% EG + 20% DMSO using SSV (47.1% and 24.0%, respectively), which showed no difference from the controls (61.2% and 46.9%, respectively). Our results clearly show that the combination of SSV and 20% EG + 20% DMSO could be used effectively to vitrify GV stage buffalo COCs. [ABSTRACT FROM AUTHOR]

Nanobased magnetic particles are synthesized by a one-pot hydrothermal precipitation of chitosan in the presence of iron(II) and iron(III) salts. The material is then chemically modified by grafting alanine and serine amino acids. These materials are characterized by elemental analysis, FTIR spectrometry, XRD analysis, TEM observations, and VSM (vibrating-sample magnetometry). In a second step, these materials are tested for uranium(VI) sorption. The effect of pH on sorption performance is first investigated before evaluating uptake kinetics (which are fitted by the pseudo-second-order rate equation) and sorption isotherms (which are modeled by the Langmuir equation). Metal desorption and sorbent recycling are finally carried out for five successive cycles of sorption/desorption. Thermodynamic parameters are determined by investigating sorption properties at different temperatures. Maximum sorption capacities reach 85 and 116 mg U g-1 for alanine- and serine-based sorbents, respectively. The magnetic properties of the particles allow their efficient separation from the solution by external magnetic field. [ABSTRACT FROM AUTHOR]

Highlights: [•] Consolidation of aluminum nano-crystals follows exponential growth with temperature. [•] Grain growth rate is reduced when the size of starting nano-crystals is increased. [•] Grain growth is accompanied by a significant reduction in the density of defects. [ABSTRACT FROM AUTHOR]

Electric arc furnace dust (EAFD) is termed as a hazardous waste due to its contamination with heavy metals. Inertization of such very fine dust can be occurred via stabilization and solidification process within the hydrated Portland cement matrix. In this paper, the effect of the addition of various ratios of EAFD on the properties of the hardened Portland cement paste was investigated. Compressive strength, chemically combine water and free lime contents were determined. In addition, phase composition using XRD; DTA analysis; as well as microstructure of the formed hydrates for some selected samples were investigated using SEM. The obtained results showed that the paste containing 1/mass% EAFD give the highest compressive strength values at most hydration ages, specially the later ages, compared to the neat Portland cement blank paste. Whileas, the pastes containing 3 and 5/mass% EAFD showed lower values of compressive strength compared to those of the blank paste. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mechanical strength of nano-scale aluminum single crystals decays exponentially as the crystal size increases. [•] Small single crystals possess larger strength due to their ability to continuously form vacancies and recover them. [•] Large single crystals tend to form grains at their surfaces upon deformation [Copyright &y& Elsevier]

Abstract: Objectives: : Evaluation of immunological alterations in the blood of human lindane poisoning cases. Design and methods: : Serum IgG, IgM, IgA, IgE, IL-2, IL-4, TNF-α, and IFN-γ levels were measured using immunoassay in 20 human cases of lindane poisoning. The presence of lindane in blood was confirmed by HPLC. Results: : Serum IL-2, IL-4, and TNF-α levels were significantly raised with decrease in IFN-γ levels in the lindane-exposed cases. Immunoglobulin levels were not altered. Conclusions: : The results suggest that lindane exposure at chronically high levels affects cytokine levels in humans and indicates the severity of immunotoxicity. [Copyright &y& Elsevier]

The goal of this work was to investigate the effect of gamma irradiated entomopathogenic nematode EPN; Steinernema scapterisci on third and fourth larval instars of Culex pipiens under laboratory conditions and its effect on the elemental composition of the treated larvae. Results showed that normal and irradiated tested nematodes differed in their efficacies against third and fourth larval instars. The mortality rates increased with increasing the nematode concentration and the period after treatment, in most cases the mortality in fourth instar larvae was more than in third instar larvae under the same treatments, and the percentage of mortality in irradiated nematodes was more than that in unirradiated ones. Studying the elemental composition showed that phosphorus (P) was the highest concentration in untreated larvae or those treated with normal S. scapterisci, while calcium (Ca) was the highest concentration in gamma irradiated S. scapterisci. The lowest concentration in untreated larvae was zinc (Zn), while copper (Cu) was the lowest concentration in unirradiated and 2 Gy gamma irradiated S. scapterisci. In conclusion, the gamma irradiation of S. scapterisci enhanced its efficacy against C. pipiens, therefore it could serve as safe control method for C. pipiens. [ABSTRACT FROM AUTHOR]

Objective: We believe optimal management of rectal cancer should be tailored to the individual patient. This is achieved by close liaison within a well established multidisciplinary team (MDT). Patients also benefit from the unusual alliance between our district general hospital (DGH) and regional oncology centre with expertise in radiotherapy for rectal cancer. To test our beliefs we reviewed the incidence of local recurrence following curative resection for rectal cancer. Method: A total of 201 consecutive cases of rectal cancer treated from 01/04/1999 to 31/03/2002 were reviewed by one author (GK). 100% case note retrieval was achieved of which 122 curative resections were identified (122/201 = 60.7%). Mean follow up 4½ years. Conclusion: The incidence of local recurrence was 2.5% (3/122). All occurred in patients having Hartmann's operation. There were no local recurrences following anterior resection or abdomino–perineal resection. Discussion: Data support our belief that, combining modern surgical techniques with radiotherapy +/- chemotherapy, high quality outcomes are achievable when care is tailored to individuals by a functional MDT. [ABSTRACT FROM AUTHOR]

Objective: We believe optimal management of rectal cancer should be tailored to the individual patient. This is achieved by close liaison within a well-established multidisciplinary team (MDT). Patients also benefit from the unusual alliance between our district general hospital and regional oncology center with expertise in radiotherapy for rectal cancer. To test our beliefs, we reviewed the incidence of local recurrence following curative resection for rectal cancer. Method: A total of 201 consecutive patients with rectal cancer treated from 1 April 1999 to 31 March 2002 were reviewed by one author (GK). 100 per cent case note retrieval was achieved of which 122 curative resections were identified (122/201 = 60.7%). Mean follow-up 4½ years. Conclusion: The incidence of local recurrence was 2.5% (3/122). All occurred in patients having Hartmann's operation. There were no local recurrences following anterior resection or abdomino-perineal resection. Discussion: Data support our belief that, combining modern surgical techniques with radiotherapy ± chemotherapy, high quality outcomes are achievable when care is tailored to individuals by a functional MDT. [ABSTRACT FROM AUTHOR]