Developing an Interactive Spatial Multi-Attribute Decision Support System for Assessing Water Resources Allocation Scenarios

Water Resources Management - In water resource management, assessing water resource allocation scenarios (WRASs) is an important multi-attribute decision making (MADM) problem. It involves...     

Investigation of Creep Feed Grinding Parameters and Heat treatment Effects on the Nickel-base Superalloys

The Nickel base Superalloys are the most famous complicated and useable of Superalloys to make hot zone components of the gas turbines. The complicated dimensional tolerances, specially at the root of the blade show importance of grinding processes at the production of blades root. The prediction of the effect of machining parameters on the soundness of component surface strengthening for reaching to a suitable surface finishing and avoiding from crack formation at the work part during machining operation often is not easy and feasible so needs to more industrial investigation.This research is about frame 5 blade designed by GE and made from Superalloy IN738LC has been investigated. The formation of a plastically deformed and heat affected zone during grinding of Superalloy IN738LC with a high depth of cut but slow work speed (creep feed grinding) was investigated. Parameters such as work speed, depth of cut and radial dressing speed have been considered as variables and their effects have been studied. During experimental performed, the voltage and current of motor measured and power and special energy calculated.Some samples heat-treated (of the 1176℃ for 1 hr under neutral argon gas and cooling rate of 15℃/min up to 537℃ and then air cooling) to study grains recrystallization. Other samples have been created from the roots of blades and then coated by Nickel to measure boundary layer micro-hardness. The results show that increasing work speed leads to increasing the use power. Increasing the depth of cut, by increasing material removal rate, and the radial dressing speed, by decreasing power, lead to decreasing special energy. The temperature created by grinding lead to decreasing plastic deformation and boundary layer formation. When the radial dressing speed changes from 1 to 0.6μm/rev and other parameters are kept unchanged the roughness of surface increases and the special energy decreases. Sufficient dressing is very essential in limiting the width of the molten zone to few micrometers. As a result, it was found that local melting at contact spots to be a rather common mechanism during grinding of superalloys, lead to so-called white layers which can easily be observed on metallographic cross sections.     

Formulation and characterisation of nanosuspensions of BCS class II and IV drugs by combinative method

Drug nanocrystals are known to increase the solubility of Biopharmaceutics Classification System (BCS) class II and IV drugs. SmartCrystals are the second generation nanocrystals with particle size of less than 100 nm and increased the stability and solubility of drug and drug product. The combinative methods adopted for the preparation of SmartCrystals are reported to shorten the processing time to reduce the particle size of the drug. This study was carried out with the aim to prepare nanosuspensions of aprepitant and ibuprofen using two pretreatment methods, precipitation and ball milling in a combination of high-pressure homogenisation (HPH). Ball milling and precipitation resulted in nanosuspensions having a particle size less than 1 µ, which were subjected to high HPH. HPH further led to a reduction in the particle size. However, the precipitation method failed to reduce the size of ibuprofen particles to 1 µ.     

Robust audio watermarking algorithm based on DWT using Fibonacci numbers

Multimedia Tools and Applications - This paper presents a blind and robust audio watermarking algorithm developed based on Fibonacci numbers properties and the discrete wavelet transform (DWT)...     

On the static and dynamic selectivity study of a sodium sensor

This paper describes the measurement of selectivity coefficients of a potentiometric sodium sensor based on a ceramic membrane and its response to interfering ions. An acquisition subsystem is realized around the 68MC701. Microcontroller to drive the analog part which multiplexes four channels at high input impedance (more than 1000 GΩ). The system is used for data acquisitions from ions sensors with different realizations. The output voltages are plotted against time to show the evolution of the output signals for different interfering ions (Potassium, Calcium, and Lithium). Hence, four sensors with membranes sintered at 900, 1000, 1150, and 1200°C have been characterized. An experimental setup has been realized and adapted to the subsystem to study the transient interferences. Experimental results are given to show the effect of disturbance in the static and dynamic cases     

Polymeric azo pigments

Summary 1-(2-Nitrophenylazo)-2-hydroxy-acryloyloxynaphthalenes were polymerized and copolymerlzed with styrene In dichloroethane using AIBN as the Initiator. The resulting colored polymers were characterized by U.V. spectroscopy and their molar masses were determined using Size Exclusion Chromatography. It was shown that the obtained products consist of mixtures of the appropriate copolymers and homopolymerized acryloyl-azo naphthols.     

An anonymous and untraceable password‐based authentication scheme for session initiation protocol using smart cards

Recently, Zhang et al. proposed a password‐based authenticated key agreement for session initiation protocol (Int J Commun Syst 2013, doi:10.1002/dac.2499). They claimed that their protocol is secure against known security attacks. However, in this paper, we indicate that the protocol by Zhang et al. is vulnerable to impersonation attack whereby an active adversary without knowing the user's password is able to introduce himself/herself as the user. In addition, we show that the protocol by Zhang et al. suffers from password changing attack. To overcome the weaknesses, we propose an improved authentication scheme for session initiation protocol. The rigorous analysis shows that our scheme achieves more security than the scheme by Zhang et al. Copyright © 2014 John Wiley & Sons, Ltd.     

In vitro properties of nano-hydroxyapatite/chitosan biocomposites

In vitro behavior of the composites was performed in simulated body fluid (SBF) to induce the formation of bone-like apatite layer onto their surfaces and its enhancement in the presence of citric acid (CA). The results proved the mineralization of calcium (Ca²⁺) and phosphorus (P) ions onto the composites which contain high chitosan concentration especially after longer time of immersion. The degradation data decreased with increase chitosan content especially C2 composites (containing 30% chitosan) and highly decreased in the presence of CA which increased binding strength through the composite. The swelling % increased with increase of chitosan content in HA composite but it decreased with CA addition as increase of interaction between three matrices. The Fourier Transformed Infrared Spectroscopy (FT-IR) and Scanning Electron Microscope (SEM-EDAX) confirmed the formation of bone-like apatite layer on the surface of the composites especially these containing CA. These biocomposites have unique in vitro properties for bone substitute's applications in the future.     

Cinétique de migration de l’eau sous charge variable dans les systèmes plâtre-argile

Résumé Les platres β sont, après consolidation, des matériaux essentiellement macroporeux (r>100 nm) donc constituent des milieux dans lesquels l’eau liquide peut facilement migrer. L’objectif du travail a été d’essayer de remédier à cet inconvénient en incorporant au platre avant consolidation des solides finement divisés: minéraux argileux de différents types (kaolinite, montmorillonite, mica muscovite, talc, sépiolite et attapulgite) ou liants particuliers constitués d’un minéral argileux thermiquement activé (métakaolinite) additionné ou non d’hydroxyde de calcium ou de ciment Portland artificiel. Le travail a permis de montrer que l’addition de solides divisés précités abaisse la distribution des rayons de pores et, excepté le mélange ‘métakaolin-chaux’, la vitesse de migration de l’eau dans le matériau à des degrés plus ou moins divers. Les résultats concernant ce dernier point ont été obtenus à l’aide d’un montage original permettant l’étude de la migration de l’eau sous charge variable. Une modélisation théorique du phénomène, basée sur une loi de Darcy modifiée, et prenant en compte les valeurs expérimentales des coefficients de perméabilités, des distributions des rayons de pores et de la porosité totale ouverte des matériaux, a pu être proposée.

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Summary After hardening, β-hemihydrate plasters are essentially macroporous materials (r>100 nm) and constitute media into which liquid water can easily migrate. The aim of the present work was to try to remedy such an inconvenience by incorporating into the material, before hardening, finely divided solids such as clay minerals (kaolinite, montmorillonite, muscovite, talc, sepiolite and attapulgite) or a thermally activated clay mineral (metakaolinite) added or not with calcium hydroxide or ordinary Portland cement. The research has allowed us to point out that the abovementioned solids decrease both the pore size distribution and, except for metakaolinite-lime addition, the water migration rate into the material. Results concerning the last point have been obtained by using an original experimental set-up allowing the study of water migration with variable hydraulic charge. A theoretical modelling of the phenomenon, taking into account experimental values of permeability coefficient, pore size distribution and total open porosity of the materials, has been proposed.

     

Design drivers for buoyant gravity‐based foundations

Buoyant gravity‐based foundations (GBFs) have been proposed as an alternative to conventional lifted GBFs, with the objective to negate the need for costly transportation vessels and thereby provide a more cost‐effective foundation option. However, in order for the foundation to remain stable during float‐out, towing and ballasting, the floatability and hydrodynamic stability of the foundation has to be proven. Maintaining hydrodynamic stability depends on many parameters, most importantly the foundation configuration, geometry and total weight, as well as water depth and ballasting sequence among other factors. This study investigates the performance of GBFs with various geometrical attributes during float‐out and ballasting operations, using a parametric study with water depths ranging from 30 to 50 m. The impact of each parameter on the variation of metacentric height of the foundation during ballasting and the initial drafts at float‐out was studied. The most suitable geometries for each water depth were investigated based on a preliminary analysis of the hydrodynamic stability. One limitation of this work is that the hydrodynamic wave forces acting on the foundation have not been considered—this is the subject of an ongoing experimental programme, which will be published in a follow‐on paper. However, this paper does consider the geotechnical stability of gravity‐based foundations and the potential modes of failure because of soil‐structure interaction. Upper and lower ballast limits were quantified in order to satisfy the geotechnical stability requirements of the foundation for various combinations of water depth/ base diameter. Copyright © 2015 John Wiley & Sons, Ltd.