Investigation of the changes in physical properties of PES/PVC fabrics after aging

The aim of this work was to investigate the physical and mechanical performance of architectural polyester (PES)–poly(vinyl chloride) (PVC) membranes exposed to different artificial aging conditions. Two commercially available architectural membranes were chosen as research objects. The durability of the PES/PVC fabrics was evaluated by the loss in mechanical performance, scanning electron microscopy, and X-ray diffraction analysis in order to understand the effect of the degradation agents on the surface of the membranes. The mechanical performance of the PES/PVC membranes was unchanged. Scanning electron microscopy images of the tested materials showed initial cracks after aging. The X-ray fluorescence analysis showed that at the time of aging, the amount of Cl and Si decreased slightly, while Ti decreased by half, and Ca by volume increased twice. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47523.     

Systemic and intracerebroventricular injections of vasotocin inhibit appetitive and consummatory components of male sexual behavior in Japanese quail.

The authors investigated the behavioral actions of vasotocin (VT) in castrated testosterone-treated male Japanese quail. The appetitive and consummatory components of sexual behavior as well as the occurrence frequency of crows were inhibited, in a dose-dependent manner, by injections of VT. The authors observed opposite effects after injection of the V1 receptor antagonist, dPTyr(Me)AVP. Lower doses of VT were more active after central than after systemic injection, and effects of systemic injections of VT were blocked by a central injection of dPTyr(Me)AVP. The behavioral inhibition was associated with a modified diuresis after systemic but not central injection. These results provide direct evidence that VT affects male sexual behavior in quail by a direct action on the brain independent of its peripheral action on diuresis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

TEM characterization of some crude or air heat-treated SiC Nicalon fibres

Commercial Nicalon fibres were prepared by thin transverse sectioning and studied by transmission electron microscopy. A progressive tilting of the incident beam allows us to explore the selected-area diffraction (SAD) pattern along two orthogonal directions, increasing the tilting angle (dark-field (DF) imaging). The lattice fringes technique was also used. The samples were Nicalon 001, 101 and 201 fibres, the latter also being studied after heat treatment in air at 1300° C for 48 h. The SAD pattern of the 001 fibre only shows the SiC, 1 1 intense halo whereas the other samples show all the SiC (1 1 1, 2 2 0 and 31 1) strongly scattered beams, indicating a microcrystalline state. Correspondingly, DF imaging does not indicate any localized measurable scattering domain for 001. Only bright dots can be seen, less than 1 nm in size. The other fibres show SiC microcrystals respectively 2 nm (1 01 ), 3 nm (201 ) and up to 7 nm (heat-treated 201) in extent. Free aromatic carbon, shaped in small units less than 1 nm in size fills up the interstices between SiC. These units tend to lie flat on SiC. In heat-treated fibres, they form incomplete layers around the edges. In addition, the heat-treated 2 01 fibre show a 1m thick layer of cristobalite at the fibre surface. These crystals are polytypes.     

Determination of the Optimal Fourier Number on the Dynamic Thermal Transmission

This article represents the result of experimental research on transient heat transfer in a multilayered (heterogeneous) wall. Our non-steady thermal transmission simulation is based on a finite-difference calculation method. The value of a Fourier number shows the similarity of thermal variation in conditional layers of an enclosure. Most scientists recommend using no more than a value of 0.5 for the Fourier number when performing calculations on dynamic (transient) heat transfer. The value of the Fourier number is determined in order to acquire reliable calculation results with optimal accuracy. To compare the results of simulation with experimental research, a transient heat transfer calculation spreadsheet was created. Our research has shown that a Fourier number of around 0.5 or even 0.32 is not sufficient (\({\approx }17\,\%\) of oscillation amplitude) for calculations of transient heat transfer in a multilayered wall. The least distorted calculation results were obtained when the multilayered enclosure was divided into conditional layers with almost equal Fourier number values and when the value of the Fourier number was around 1/6, i.e., approximately 0.17. Statistical deviation analysis using the Statistical Analysis System was applied to assess the accuracy of the spreadsheet calculation and was developed on the basis of our established methodology. The mean and median absolute error as well as their confidence intervals has been estimated by the two methods with optimal accuracy (\({F}_{\mathrm{oMDF}}= 0.177\) and \(F_{\mathrm{oEPS}}= 0.1633\) values).     

A framework for virtual organization requirements

Virtual organizations (VOs) are formed by an alliance of organizations linked by a partnership for dealing with emerging challenges. Information and communication technologies play a fundamental role facilitating cooperation, communication and collaboration among the VO members. The formal identification and representation of Requirements Engineering (RE) for one organization have been researched to a large extent along with several elicitation techniques. However, these techniques are not adequate for covering the major challenges of RE for VO. We explore the work done in the management and RE fields to propose a model-based framework for eliciting VOs’ requirements. The goal is to analyze the VO from two points of view: border (intra-organizational, inter-organizational and extra-organizational) and abstract (intentional, organizational and operational). This article includes the framework validation with a case study and a transformation process to develop partial Business Process Diagram from the intentional models.     

A participative end-user method for multi-perspective business process elicitation and improvement

A business process can be characterized by multiple perspectives (intentional, organizational, operational, functional, interactional, informational, etc). Business process modeling must allow different stakeholders to analyze and represent process models according to these different perspectives. This representation is traditionally built using classical data acquisition methods together with a process representation language such as BPMN or UML. These techniques and specialized languages can easily become hard, complex and time consuming. In this paper, we propose ISEA, a participative end-user modeling approach that allows the stakeholders in a business process to collaborate together in a simple way to communicate and improve the business process elicitation in an accurate and understandable manner. Our approach covers the organizational perspective of business processes, exploits the information compiled during the elicitation of the organizational perspective and touches lightly an interactional perspective allowing users to create customized interface sketches to test the user interface navigability and the coherence within the processes. Thus, ISEA can be seen as a participative end-user modeling approach for business process elicitation and improvement.     

Numerical Schemes for Variational Inequalities Arising in International Asset Pricing

This paper introduces a valuation model of international pricing in the presence of political risk. Shipments between countries are charged with shipping costs and the country specific production processes are modelled as diffusion processes. The political risk is modelled as a continous time jump process that affects the drift of the returns in the politically unstable countries. The valuation model gives rise to a singular stochastic control problem that is analyzed numerically. The fundamental tools come from the theory of viscosity solutions of the associated Hamilton–Jacobi–Bellman equation which turns out to be a system of integral-differential Variational Inequalities with gradient constraints.     

Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta).

The authors tested 90 rhesus monkeys (Macaca mulatta) on a task of spatial memory, the spatial Delayed Recognition Span Test. The results showed that performance declined significantly with age, males had greater scores than females, and the rate of apparent decline with age was greater in males than in females. Both working and reference memory declined with age, but only working memory showed sex differences. The authors compared these data with that of 22 monkeys who were trained on a simpler version of the task before formal testing. Training had no effect on males but dramatically improved working memory in young females. The results confirm a male advantage in spatial working memory at a young age and confirm a greater decline with age in males than in females. It is important to note that prior training completely reverses the deficits of young females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical and experimental investigations of mixing in T-shaped and cross-shaped micromixers

Mass transfer within the T-shaped and cross-shaped micromixers has been studied using CFD and confocal laser scanning microscopy methods. The concentration profiles, based on flow regimes, were used to compare the T- and cross-geometries. The cross-shaped micromixer tends to intensify the mixing and this is occurring for lower flow rates in comparison to the T shape. The improvement made by the cross geometry is attributed to the stronger vortex stretching and high shear rate, which reduces the liquid transfer length. The presence of a single outlet in the T-shaped micromixer induces a smaller degree of freedom for the fluid. A higher pressure drop is calculated in T-shaped micromixer than in cross-shaped micromixer.