Numerical simulations have been carried out for highly under-expanded jet from an accidental release of high-pressure hydrogen–oxygen mixture into the atmospheric pressure by using KIVA-3V software. The original KIVA-3V [1] solves 3-D unsteady transport equations of a turbulent, and the chemically reactive mixture of gases. The gas phase solution procedure is based on a finite volume method called ALE (Arbitrary Lagrangian-Eulerian) method. A shock structure from the under-expansion is numerically resolved in a small computational domain above the jet exit. In this paper the investigate of a high pressure jet (30 MPa) of hydrogen-oxygen mixture by using a directed numerical simulation have been conducted. A small hole of 2 mm is assumed to be opened on the wall of a tank and a chocked mixture is injected to air. The autoigniton of pressurized hydrogen-oxygen mixture was predicted to first take place downstream of the Mach dick as the mixture heated to self-ignition temperature. Such knowledge is valuable for studying the ignition characteristics of high-pressure hydrogen jets in the safety context.

In this paper we study the use of the Brill tagger [5,6,7] for tagging Modern Standard Arabic (henceforth MSA) text. The Brill tagger is a famous public domain part of speech tagger, originally designed for tagging English text by implementing machine learning approach through the method of transformation rules. IT had been adopted for other languages by many researchers [17,19,22]. Some modifications are needed on the learner and tagger that are written partly in perl and partly in C programming languages, and are run under the unix/linux operating system. The main change is done on the initial state tagger, which is used by both learner and tagger. A program is written using the lexical analyzer Lex to capture Arabic morphological structures, and then interfaced with both learner and tagger. The tagset used in this work is a revised version of that introduced by Khoja [11]. The revision included changing some of the tags for linguistic considerations and introducing some new tags to make the set more powerful, or to make up for limitations in the original tagset that hinder tagging some words. The corpus is obtained from two Jordanian magazines, and has to go through a series of editing steps. A collection of lexical rules and contextual rules are obtained and applied to Arabic text. The tagging accuracy of the resulting tagged text is measured now to be an average of up to about 84% for both known and unknown words, A rate, which is very promising for such a complex language and rich tagset. We still hope for better performance.

Abstract

The paper presents studies on numerical modelling of beam-to-column joint behaviour in typical service and exceptional design situations. The complexity of such investigations arises from highly nonlinear effects associated with the prediction of joint performance, such as structural imperfections, large displacements and rotations, inelastic properties of steel and concrete, bonding effects between steel and concrete, and slip between concrete and structural steel, among others. The paper addresses these problems and provides validation of numerical modelling techniques trough comparison with experimental data for joints under hogging and sagging moments. © (2012) Trans Tech Publications.

Increasing concern for environment has made building owners and designers to incorporate green design into their building projects. Buildings take about 40 per cent of energy consumption globally and have significant impact on the productivity and wellbeing of the occupants. However, the quality of design team attributes the quality of clients and the characteristics of the building projects have been argued to be the main factors that determine the green design performance of buildings. Therefore, the main objectives of this study are to measure the green design building performance, the quality of client and the attributes of the design team. This study also measures the extent to which the quality of design team attributes, the quality of clients and the characteristics of the building projects affect the green design performance of buildings.The study adopted a triangulation technique that combined both quantitative and qualitative methods of data collection.

echnology enhanced Learning

A new class of high‐performance resins of combined molecular structure of both traditional phenolics and benzoxazines has been developed. The monomers termed as methylol‐functional benzoxazines were synthesized through Mannich condensation reaction of methylol‐functional phenols and aromatic amines, including methylenedianiline (4,4′‐diaminodiphenylmethane) and oxydianiline (4,4′‐diaminodiphenyl ether), in the presence of paraformaldehyde. For comparison, other series of benzoxazine monomers were prepared from phenol, corresponding aromatic amines, and paraformaldehyde. The as‐synthesized monomers are characterized by their high purity as judged from ¹H NMR and Fourier transform infrared spectra. Differential scanning calorimetric thermograms of the novel monomers show two exothermic peaks associated with condensation reaction of methylol groups and ring‐opening …

The design phase is the most important phase in determining the green performance of building projects. The performance of the design team is crucial. The growing importance of sustainability globally necessitates the inclusion of green criteria in the design team selection process. Therefore, a competent design teams is required to have a range of attributes as the basis for design decisions. The propose of this study to identify current green design performance level of design teams of building projects and establish key design attributes influencing green design performance. To achieve mentioned aim a questionnaire survey was conducted to collect dada required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. In general, design team attributes were moderate (3.32). The general design team attributes were high such experience (3.81), communication (3.43) and leadership effectiveness (3.48). However, green attributes of design team were moderate such as green knowledge (2.98), green skills (3.13) and green initiatives (2.84). The result indicates that most design teams have inadequate knowledge and skills to produce high green design performance of building projects. Therefore, to overcome green design complexity, careful selecting design team members and more education and training courses on green building are required to deal with green design requirements.

The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical

properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical

testing. The addition of Cr, Mn and Mo leads to a decrease in yield strength (YS) by approximate 100 MPa in

comparison to the base steel. It is assumed that Mn and Mo increase hardenability by promoting the formation

of bainitic sheaves (BS), i:e: by suppressing the formation of ferrite-pearlite and acicular ferrite (FP-AF). Cr

at the level used in this work is not that e®ective. Presence and packet size of bainitic sheaves decrease

the Charpy V-notch impact energy at 20 ±C (CVN20) in comparison to ferrite-pearlite and acicular ferrite

microstructures.

The aim of this work was to investigate whether the Malaysian current building projects are considered as “Green Designs”. To achieve this aim a questionnaire survey was conducted. A sample of 274 respondents is covered, which included architects and engineers in the building design and consultancy sectors. WINSTEPS software is used in Rasch modeling to determine the validity and reliability of the data. Descriptive data analysis (quantitative and qualitative) is done. The results reveal that design green building performance, in general, energy efficiency, and indoor air quality requirements are considered moderate. The majority of the designed buildings are with low utilization of recycled and reused materials. Moreover, high utilization of regional materials, low consideration to water efficiency requirements and environmental innovations are also moderate. Design team attributes are the key factors to improve green design performance. Client quality play major role to enhance design team attributes. Therefore, effective Design team attributes and client’s qualities may increase performance of the design green building performance in order to enhance building performance and reduce building impact on environment.