Extracting trust information from security system of a service

The issue of trust is a research problem in emerging open environments, such as ubiquitous networks. Such environments are highly dynamic and they contain diverse number of services and autonomous entities. Entities in open environments have different security needs from services. Trust computations related to the security systems of services necessitate information that meets needs of each entity. Obtaining such information is a challenging issue for entities. In this paper, we propose a model for extracting trust information from the security system of a service based on the needs of an entity. We formally represent security policies and security systems to extract trust information according to needs of an entity. The formal representation ensures an entity to extract trust information about a security property of a service and trust information about whole security system of the service. The proposed model is applied to Dental Clinic Patient Service as a case study with two scenarios. The scenarios are analyzed experimentally with simulations. The experimental evaluation shows that the proposed model provides trust information related to the security system of a service based on the needs of an entity and it is applicable in emerging open environments.     

Determination of optimum pH and temperature for pasteurization of citrus juices by response surface methodology

Summary Optimization of microbial death, enzyme inactivation and vitamin C retention during pasteurization of pH-adjusted orange juice is discussed free of equipmentdependent parameters such as the heating lag. The pH-temperature optimum was determined by response surface methodology in the range of 65° C–75° C and pH 2.5–4.0. The results implied that there was no pectinesterase activity below pH 3.5.Leuconostoc mesenteroides had its maximum and minimum thermal resistance at pH 3.5 and pH 2.7, respectively. For an ideal theoretical process requiring four log cycles of microbial reduction the optimum pasteurization conditions were 12 min at 75° C and pH 2.7.

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Bestimmung der optimalen Temperatur- und pH-Wert-Bedingungen für die Pasteurisierung von Citrussäften mit der response surface-Methode

Zusammenfassung Die Optimierung der mikrobiellen Abtötung, Enzyminaktivierung und Vitamin-C-Retention während der Pasteurisierung von Orangensaft mit verschiedenen pH-Werten wird, frei von Anlageneinflüssen, wie z. B. Erhitzungsverzögerungen, diskutiert. Das Temperatur-pH-Wert-Optimum wurde mit der response surface-Methode im Temperaturbereich von 65 bis 75 °C und pH-Werten zwischen 2,5 und 4,0 untersucht. Die Ergebnisse lassen darauf schließen, daß unter pH 3,5 keine Pectinesteraseaktivität mehr vorliegt.Leuconostoc mesentroides wies bei pH 2,7 minimale und bei pH 3,5 maximale Hitzeresistenz auf. In einem idealen theoretischen Pasteurisierungsprozeß, der eine Reduzierung der mikrobiellen Belastung um vier Größenordnungen erfordert, liegen die optimalen Bedingungen bei 12 min, 75 °C und einem pH-Wert von 2,7.

     

Novel colloidal nanofiber electrolytes from PVA‐organoclay/poly(MA‐alt‐MVE), and their NaOH and Ag‐carrying polymer complexes

Novel multifunctional polymer nanofiber electrolytes with covalence crosslinked structures from various solution blends of reactive intercalated poly(vinyl alcohol)/octadecylamine montmorillonite (as a matrix polymer), poly(maleic anhydride‐alt‐methyl vinyl ether) (as a partner polymer) and their NaOH‐absorbing and Ag‐carrying polymer complexes were fabricated via electrospinning. Chemical, physical, morphological, and electrical properties of nanofiber structures were investigated by FTIR, XRD, SEM, and electrical analysis methods. Ag precursors in fiber composites significantly improved phase separation processing, fiber morphologies, diameter distributions, and electrical properties of the fibers. In situ generation of Ag nanoparticles and their distribution on nanofiber surfaces during fiber formation occurred via complex formation between silver cations and electronegative functional groups from both matrix and partner polymers as stabilizing/reducing agents. Electrical resistance and conductivity strongly depended on matrix/partner polymer ratios and absorption time of NaOH solution on nanofibers. Addition of NaOH changed the electrical properties of fiber structures from almost dielectric state to excellent conductivity form. The fabricated unique nanofiber electrolytes are promising candidates for applications in power and fuel cell nanotechnology, electrochemical, and bioengineering processes as reactive semiconductive platforms. POLYM. ENG. SCI., 56:204–213, 2016. © 2015 Society of Plastics Engineers     

Rapid Discovery of Aspartyl Protease Inhibitors Using an Anchoring Approach

Pharmacophore searches that include anchors, fragments contributing above average to receptor binding, combined with one-step syntheses are a powerful approach for the fast discovery of novel bioactive molecules. Here, we are presenting a pipeline for the rapid and efficient discovery of aspartyl protease inhibitors. First, we hypothesized that hydrazine could be a multi-valent warhead to interact with the active site Asp carboxylic acids. We incorporated the hydrazine anchor in a multicomponent reaction and created a large virtual library of hydrazine derivatives synthetically accessible in one-step. Next, we performed anchor-based pharmacophore screening of the libraries and resynthesized top-ranked compounds. The inhibitory potency of the molecules was finally assessed by an enzyme activity assay and the binding mode confirmed by several soaked crystal structures supporting the validity of the hypothesis and approach. The herein reported pipeline of tools will be of general value for the rapid generation of receptor binders beyond Asp proteases.     

Analysis of interaction between tunnels in soft ground by 3D numerical modeling

Tunnels are increasingly being excavated in soft ground conditions when services are required in urban environments, and it is now common to have tunnels crossing at various elevations. As the tunnel excavations are undertaken at different levels, there will be an interaction which can have a significant influence on stress distributions and consequently deformations within the tunnels and surface settlement. As multi-layer tunnelling is a three dimensional phenomenon in nature, 3D numerical solutions must be utilized for perpendicularly crossing tunnels at various levels. This paper reports the investigations into the changes in stress distribution, deformations and surface settlements which may be expected when the twin Tohid Tunnels pass beneath the Line 4 metro tunnel in Tehran.     

Experimental evaluation of polycrystalline diamond tool geometries while drilling carbon fiber-reinforced plastics

Polycrystalline diamond (PCD) drills are commonly employed in carbon fiber-reinforced plastic (CFRP) drilling to satisfy hole quality conditions with an acceptable tool life and productivity. Despite their common use in industry, only a small number of studies have been reported on drilling CFRPs with PCD drills. In this study, drilling performances of three different PCD drill designs are investigated experimentally using thrust force, torque, and hole exit quality measurements. Results show that work material properties, drilling conditions, and drill design should all be considered together during the selection of process parameters, and the relationships among these factors are quite complex.     

Follicular fluid of women with endometriosis stimulates the proliferation of endometrial stromal cells

The peritoneal environment in endometriosis is known to have growth-promoting effects on endometrial cells. To investigate whether follicular fluid, a contributor to the peritoneal fluid, stimulates endometrial cell proliferation, we incubated endometrial stromal cells in culture with various dilutions of follicular fluid obtained from women with or without endometriosis undergoing oocyte retrieval for in-vitro fertilization. Cell proliferation assays were performed using follicular fluid from 28 women (without endometriosis, n = 13; with endometriosis, n = 15) in eight different endometrial stromal cell culture set-ups. Cell proliferation was assessed by a colorimetric method. Maximum cell proliferation was detected when endometrial cells were incubated with 50% dilution of follicular fluid for 48 h. Follicular fluid from women with endometriosis induced significantly higher cell proliferation than follicular fluid from women without endometriosis (P < 0.05). Our findings indicate that follicular fluid contents may contribute to the growth-promoting factors in the peritoneal fluid of women with endometriosis.     

On the drop-weight testing of alumina/aluminum laminated composites

Laminated composites with ceramic front layers and metallic or composite backing layers have gained attractiveness as lightweight armours, as they exhibit the same ballistic performance with lower areal densities as compared to steels. Drop-weight testing (DWT) has potential for evaluating the low velocity impact behaviour of materials. This testing gives significant ideas and information about failure mechanisms and behaviour of materials under low velocity impact. In this study, DWT of alumina/aluminum laminated composites was done in order to investigate the effects of lamination type, density with respect to area and mechanical property of backing material on the low velocity ballistic performance of these composites. The experimental results showed that the laminated composite with ceramic front layer and aged-aluminum alloy as backing layer was the most effective among different investigated specimens against low velocity impact loads.     

Three-dimensional application of the Johnson-King turbulence model for a boundary-layer direct method

The Johnson-King turbulence model[1; AIAA Paper 84-0175 (1984)] as extended to three-dimensional flows was evaluated using a finite-difference boundary-layer direct method. Calculations were compared against the experimental data of the well-known van den Berg-Elsenaar[2; Report NLR-TR-72092U (1972)] incompressible flow over an infinite swept-wing, as well as with some other boundary-layer methods. The Johnson-King turbulence model, which includes the non-equilibrium effects in a developing turbulent boundary layer, was found to significantly improve the predictive quality of a direct boundary-layer method. The improvement was especially visible in the computations with increased three-dimensionality of the mean flow, larger integral parameters and decreasing eddy-viscosity and shear-stress magnitudes in the streamwise direction; all in better agreement with the experiment than simple mixing-length-based methods.