Landscape change in Ramallah—Palestine (1994–2014)

The Palestinian landscape has always been subjected to dynamic processes of change. This article examines the landscape change in Ramallah city during the last 20 years by analysing two aerial photographs from two periods—1994 and 2014—to create land cover maps which illustrate the change in different landscape classes in the city. The article aims to quantify the landscape change in the specified periods using GIS and FRAGSTATS analysis, and to identify and explain spatial patterns of the landscape, taking into consideration the political, social, and economic circumstances. The results reveal a considerable change and fragmentation. The main change is an increase in the built-up area at the expense of a decrease in the permanent trees and scrub areas. This change, due to the occupation policies, is a reflection of many indicators, including population growth, migration, and an economic boom in the construction sector.     

Magneto-visco-elastic surface waves in stressed conducting media

The present paper is concerned with magneto-visco-elastic surface waves in conducting media involving time rate of strain and stress of first order, the media being under an initial stress of hydrostatic tension or compression. The theory of magneto-visco-elastic surface waves in a conducting medium involving time rate of strain and stress of first order is derived under an initial stress. The above general theory is then employed to characterise Rayleigh, Love and Stoneley waves. Results obtained in the above cases reduce to well-known classical results when viscosity and magnetic field are absent.     

Novel Surface Topography and Microhardness Characterization of Laser Clad Layer on TC4 Titanium Alloy Using Laser-Induced Breakdown Spectroscopy and Machine Learning

Metallurgical and Materials Transactions A - This study was performed to characterize surface topography and microhardness of 40 wt pct NiCrBSiC-60 wt pct WC hard coating on TC4 titanium after...     

Impact of polyurethane yarns on the mechanical properties of braided artificial ligaments

Anterior cruciate ligaments (ACL) have to meet a number of physiological and biomechanical requirements. Most of the permanent prostheses that have been developed suffer from fatigue, creep, and mechanical failure. This study aims to develop a new braided synthetic ligament which offers a high elasticity ensuring a long-term mechanical performance. Two braided structures were designed: a biaxial quadruple braid and a triaxial quadruple braid incorporating polyurethane filaments. The mechanical properties of these structures were measured and compared to those of the natural ligaments. The elastic recovery under a traumatic force was also studied in order to compare the elasticity of the manufactured samples. The obtained results showed that the elastic recuperation was improved, thanks to the incorporation of polyurethane yarns. These yarns provide prostheses with mechanical properties that closely match those of the native ACL.     

Stability of the emulsion (W/O): application to the extraction of a Dawson type heteropolyanion complex in aqueous solution

Dawson type heteropolyanions form complexes with transition metals. These mixed complexes possess some remarkable electrocatalytic properties. Being soluble in aqueous and organic phases, they are used in homogeneous catalysis. In the setting of the recuperation and the regeneration of these complexes, the extraction of a mixed heteropolyanion (alpha 2P2W12Mo5O61Fe)(7-) is the subject of this work. This extraction was carried out by emulsified liquid membrane using (SPAN80) as surfactant and (TIBA) as extractant. Sulfuric acid was used as the internal phase. The stability of the emulsion was studied according to different parameters and the extracting efficiency in optimal conditions was found to be 70%.     

Characterization of TBP containing polysiloxane membrane/insulator/semiconductor structures for hexavalent chromium detection

A hexavalent chromium-sensitive EMIS sensor (electrolyte membrane insulator semiconductor sensor) is prepared by deposition of a tributylphosphate (TBP) ionophore-containing siloprene membrane on a Si/SiO₂/Si₃N₄ structure. The developed EMIS sensor was studied by means of impedance spectroscopy, capacitance–voltage, X-ray photoelectron spectrometry and FT-IR spectroscopy. From the flat-band shift of the EMIS structure, the nersntian response to the anionic species Cr₂O₇⁻ was demonstrated. The linear range of detection is 10^− 4 M to 10^− 1 M and the detection limit is 10^− 5 M. Sulfate and chloride anions are shown not to be interfering whereas carbonate ions present a pK^pot equal to 0.19.     

Ageing behavior of a Cu-bearing ultrahigh strength steel

On ageing at different temperatures a various combination of properties has been obtained for this Cu-bearing ultrahigh strength steel. A substantial increase in strength has been obtained at 450 °C, accompanied by a drop in percentage elongation, percentage reduction in area and toughness. At 550 °C temperature extensive -Cu precipitates have been observed. The increased strength value retained in the temperature range of 450–600 °C and a secondary hardening peak obtained at 600 °C is probably due to the formation of fine Mo carbide precipitates. The decrease in strength at 650 °C along with an increase in percentage elongation, percentage reduction in area and toughness is due to the coarsening of Cu particles and a partial recovery of matrix. At 700 °C most of the Cu precipitates become rod shaped and formation of fresh martensite with a dark contrast is observed at the lath boundaries.     

Integrated Decision Support System for Optimal Renewal Planning of Sewer Networks

Municipalities are under increasing pressure to adopt proactive and optimized renewal strategies to reduce the risks, life-cycle costs, and resources needed to maintain acceptable performance and service levels of their infrastructure assets. A new integrated approach for optimal renewal planning of municipal infrastructure systems has been developed. This paper discusses the application of the proposed approach to implement a GIS-based decision support system (DSS) to support the renewal planning of sewer networks. Condition rating, risk assessment, and prioritization techniques are described. A procedure for identifying and selecting the most suitable renewal technologies is also presented. A genetic algorithm-based multiobjective optimization technique is used to find a Pareto front of feasible solutions, each comprising a set of sewers to be renewed each year, along with the associated costs and expected benefits in terms of condition improvement and risk reduction. The paper also presents an example application of the prototype DSS on the sewer network in Regina, Canada.     

Understanding the effect of deployment on the risk of fatal motor vehicle crashes: a nested case-control study of fatalities in Gulf War era veterans, 1991-1995

Motor vehicle crashes (MVCs) are an important cause of morbidity and premature loss of life among military personnel during peacetime and particularly following combat. A nested case-control study of fatal MVC occurring between 1991 and 1995 was conducted in a cohort of Gulf War era veterans. Cases were validated MVC deaths in the Fatality Analysis Reporting System. Controls were selected using risk set sampling by gender and year of case ascertainment in a 10:1 ratio. Preliminary results, consistent with previous reports of increased fatal MVC risk among returning combat veterans, showed a crude odds ratio of 1.45 (95% confidence interval 1.27-1.65). Multivariable logistic regression modeling was used to identify important independent predictors, as well as to quantify the influence of deployment on a risk profile for fatal MVC. Because of significant interaction between deployment and inpatient diagnosis of substance abuse, the final model was stratified by deployment status. Results suggest that demographic, military, and behavioral characteristics of deployed healthy warriors are similar to the risk profile for fatal MVC. In addition to young, single, high school-educated, enlisted male personnel, those who served during times of ground combat, particularly in infantry, gun crews, or seamanship occupations, should be targeted for preventive interventions.     

Influence of Covalent Bonds on the Adhesion Energy at Elastomer-Glass Interfaces

The aim of this study was to analyze the effect of interfacial covalent bonds on the adhesive behavior of an elastomer, a crosslinked polydimethylsiloxane, and a glass substrate. These covalent bonds were created by applying to both materials an appropriate surface treatment by means of plasma polymerization. Adhesion measurements were carried out by analyzing the contact area between a rubber hemisphere and a flat rigid glass plate. The contact was forced under a given compressive loading for different times t_c, then the load was removed and the fracture propagation at the interface was recorded as a function of relaxation time t_r. Finally, adhesion energies were also determined by means of a probe test using a tensile testing machine.