72 research outputs found
THREE DIMENSIONAL SIMULATION OF SUSPENSION FLOW IN A MOLD CAVITY
ABSTRACT This paper presents three-dimensional simulation of fiber suspension flows in a cavity using the Finite Volume Method (FVM). The numerical simulation model described makes it possible to predict the propagation of the fiber-polymer solution and fiber orientation during the filling phase. Therefore, the objective of the work is to develop a Computational Fluid Dynamics (CFD) model to simulate and characterize the fiber suspension flow in three dimensional cavities. The model is intended to describe the fiber orientation distribution in three dimensional mold cavities. The continuity, momentum, energy and the fiber orientation equations are solved using the FVM. The flow is considered to be incompressible, non-isothermal, transient, and to behave as non-Newtonian fluid. A numerical analysis is presented to illustrate the application of the FVM to dilute suspension flows in injection molding processes. The volume-of-fluid method is employed to describe the flow of the two incompressible, immiscible phases, i.e., liquid suspension and air. Since the flow is a non-Newtonian, the Cross model is used to describe the shear-thinning behavior of the suspension. The governing equations of the flow and the fiber are implemented and solved by means of the open source code OpenFOAM. The evolution equation of the fiber orientation contains a fourth order orientation tensor which is approximated in terms of second order tensor through the use of appropriate closure rules. In this study the Hybrid closure model of Advani and Tucker is used to approximate the fourth order orientation tensor. To validate the numerical algorithm, test cases of suspension flow in a rectangular cavity are modeled for different fiber-polymer matrices. The numerical results are compared with available experimental findings and with those of Newtonian flows
A REVIEW OF SUSTAINABLE NEIGHBORHOOD INDICATOR FOR URBAN DEVELOPMENT IN LIBYA
ABSTRACT The sustainability of a neighborhood has a crucial role in preserving the environment for future generations. The development of neighborhoods consumes an excessive amount of land that needs to be protected. Libya must consider sustainable neighborhood indicators in its urban planning and design to allow future generations to benefit from such development. This paper focuses on issues that are related to the sustainable neighborhood indicators and development of Libya. Specifically, sustainable neighborhood development was investigated on the basis of shareholders, whereas the sustainable neighborhood indicators were examined in terms of their physical features and benefits. Results showed that sustainable neighborhood indicators of various countries are generally similar and only differ depending on their regional climate characteristics. This paper proposes several approaches for optimizing the sustainable neighborhood indicators of Libya
Optimum utilization of Clostridia species towards biofuel production
Abstract Global increasing stipulates for the production of renewable fuels due to massive utilization of readily available fossil fuel, more interests in microbial production of biofuels are generated. This opened great opportunities to the biologists, because anaerobic bacteria particularly Clostridium species are capable of converting carbohydrates into a variety of solvents such as acetone, butanol, ethanol and more the like. The review provided ample sources of information with regards to the potentialities of Clostridium species towards production of biofuels. The classification of Clostridium species into pathogenic and non-pathogenic, and those capable of biofuel production has been summarized. Typical metabolic processes responsible for transforming biomass into various biofuels have been highlighted. Utilization of agricultural wastes as substrates towards biofuel production was equally highlighted. Various carbon sources and some Clostridium species exploited for biofuel production were summarized. The review also provided some of the factors that influenced the biofuel production
Measurement of nicotine withdrawal symptoms: linguistic validation of the Wisconsin Smoking Withdrawal Scale (WSWS) in Malay
<p>Abstract</p> <p>Background</p> <p>The purpose of the linguistic validation of the Wisconsin Smoking Withdrawal Scale (WSWS) was to produce a translated version in Malay language which was "conceptually equivalent" to the original U.S. English version for use in clinical practice and research.</p> <p>Methods</p> <p>A seven-member translation committee conducted the translation process using the following methodology: production of two independent forward translations; comparison and reconciliation of the translations; backward translation of the first reconciled version; comparison of the original WSWS and the backward version leading to the production of the second reconciled version; pilot testing and review of the translation, and finalization.</p> <p>Results</p> <p>Linguistic and conceptual issues arose during the process of translating the instrument, particularly pertaining to the title, instructions, and some of the items of the scale. In addition, the researchers had to find culturally acceptable equivalents for some terms and idiomatic phrases. Notable among these include expressions such as "irritability", "feeling upbeat", and "nibbling on snacks", which had to be replaced by culturally acceptable expressions. During cognitive debriefing and clinician's review processes, the Malay translated version of WSWS was found to be easily comprehensible, clear, and appropriate for the smoking withdrawal symptoms intended to be measured.</p> <p>Conclusions</p> <p>We applied a rigorous translation method to ensure conceptual equivalence and acceptability of WSWS in Malay prior to its utilization in research and clinical practice. However, to complete the cultural adaptation process, future psychometric validation is planned to be conducted among Malay speakers.</p
Higher ethical objective (Maqasid al-Shari'ah) augmented framework for Islamic banks : assessing the ethical performance and exploring its determinants.
This study utilises higher objectives postulated in Islamic moral economy or the maqasid al-Shariâah theoretical frameworkâs novel approach in evaluating the ethical, social, environmental and financial performance of Islamic banks. Maqasid al-Shariâah is interpreted as achieving social good as a consequence in addition to well-being and, hence, it goes beyond traditional (voluntary) social responsibility. This study also explores the major determinants that affect maqasid performance as expressed through disclosure analysis. By expanding the traditional maqasid al-Shariâah,, we develop a comprehensive evaluation framework in the form of a maqasid index, which is subjected to a rigorous disclosure analysis. Furthermore, in identifying the main determinants of the maqasid disclosure performance, panel data analysis is used by including several key variables alongside political and socio-economic environment, ownership structures, and corporate and Shariâah governance-related factors. The sample includes 33 full-fledged Islamic banks from 12 countries for the period of 2008â2016. The findings show that although during the nine-year period the disclosure of maqasid performance of the sampled Islamic banks has improved, this is still short of âbest practicesâ. Through panel data analysis, this study finds that the Muslim population indicator, CEO duality, Shariâah governance, and leverage variables positively impact the disclosure of maqasid performance. However, the effect of GDP, financial development and human development index of the country, its political and civil rights, institutional ownership, and a higher share of independent directors have an overall negative impact on the maqasid performance. The findings reported in this study identify complex and multi-faceted relations between external market realities, corporate and Shariâah governance mechanisms, and maqasid performance
Impact of routine PCV7 (Prevenar) vaccination of infants on the clinical and economic burden of pneumococcal disease in Malaysia
<p>Abstract</p> <p>Background</p> <p>Pneumococcal disease is the leading cause of vaccine-preventable death in children younger than 5 years of age worldwide. The World Health Organization recommends pneumococcal conjugate vaccine as a priority for inclusion into national childhood immunization programmes. Pneumococcal vaccine has yet to be included as part of the national vaccination programme in Malaysia although it has been available in the country since 2005. This study sought to estimate the disease burden of pneumococcal disease in Malaysia and to assess the cost effectiveness of routine infant vaccination with PCV7.</p> <p>Methods</p> <p>A decision model was adapted taking into consideration prevalence, disease burden, treatment costs and outcomes for pneumococcal disease severe enough to result in a hospital admission. Disease burden were estimated from the medical records of 6 hospitals. Where local data was unavailable, model inputs were obtained from international and regional studies and from focus group discussions. The model incorporated the effects of herd protection on the unvaccinated adult population.</p> <p>Results</p> <p>At current vaccine prices, PCV7 vaccination of 90% of a hypothetical 550,000 birth cohort would incur costs of RM 439.6 million (US10.9 million) to the health system with 11,422.5 life years saved at a cost effectiveness ratio of RM 35,196 (US10,261). This is well below the WHO's threshold for cost effectiveness of public health interventions in Malaysia of RM 71,761 (US$20,922).</p
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
East meets west: when the Islamic and Gregorian calendars coincide
Recent research has documented that at the time of religious celebrations in Muslim countries, such as Ramadan, there is a âfestivalâ effect in share returns. In the Gregorian calendar, December is also a time of celebration and festivities which may be associated with patterns in the behaviour of security prices. Further, the first month of the year in the Islamic calendar, Muharram, is a time of sadness and mourning for some believers, and there may be an effect when the Islamic first month of the year overlaps with the first month of the Gregorian year - January. Over a 33-year cycle, each Islamic month falls in a Gregorian month for about 5â6 consecutive years; when this happens, an Islamic (Eastern) calendar effect may interact with a Gregorian (Western) calendar effect. The current paper addresses this issue by examining the behaviour of share returns and volatility for individual companies listed in Muslim countriesâ stock exchanges when the two calendars coincide for: (i) religious festival effects; (ii) first-month-of-the-year effects; and (iii) the two most common effects reported in the Islamic and Gregorian calendars (Ramadan and January). The results show that the Western and Eastern effects interact more prominently in larger companies and in larger or more developed markets
Ethnic differences in the occurrence of acute coronary syndrome: results of the Malaysian National Cardiovascular Disease (NCVD) Database Registry (March 2006 - February 2010)
Perception Study on Leading Factors of Slip and Fall Incidents in Manufacturing Industry
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