• Membrane and Water Treatment
• /
• v.5 no.3
• /
• pp.207-219
• /
• 2014

Fouling is one of the critical factors associated with the application of membrane technology in treating palm oil mill effluent (POME), due to the presence of high concentration of solid organic matter, oil, and grease. In order to overcome this, chemical cleaning is needed to enhance the effectiveness of membranes for filtration. The potential use of sodium hydroxide (NaOH), sodium chloride (NaCl), hydrochloric acid (HCl), ethylenediaminetetraacetic acid (EDTA), and ultrapure water (UPW) as cleaning agents have been investigated in this study. It was found that sodium hydroxide is the most powerful cleaning agent, the optimum conditions that apply are as follows: 3% for the concentration of NaOH, $45^{\circ}C$ for temperature solution, 5 bar operating pressure, and solution pH 11.64. Overall, flux recovery reached 99.5%. SEM images demonstrated that the membrane surface after cleaning demonstrated similar performance to fresh membranes. This is indicative of the fact that NaOH solution is capable of removing almost all of the foulants from PES membranes.

• Korean Institute of Interior Design Journal
• /
• v.19 no.1
• /
• pp.63-74
• /
• 2010

The purpose of this research aims to retrieve the communication which is the essential publicness in the built environment design and the self-management which is the original value in terms of sociology. To examine this, the way in which the characters of the design of the publicness have been changed will be concentrated on in the public area since 1980s, Particularly, this research has been focused on the Second modernity design which is against the aggressive utopia - oriented modernization and Reflexive Modernization which has been mentioned by Anthony Giddens, Ulich Beck, and especially Scott Lash. Also, to understand Reflexive Modernization, the realism art in the view point of the objective recognition of modernity and identity emphasized by Scott Lash will be examined. Through the analysis of the Nene Sachlichkeit which is a part of the realism art, how the reflection of the design can be the function of the design will be addressed and some examples will be analyzed in terms of communications and self-education in the design of the publicness. Thus, Contemporary Built Environment Design features are categorized into universality, objectivity, and rationality; it reaches that the past Neue Sachlichkeit meets the spirit of art; it concludes that the efforts of the reflection of the modernity, intensity and development in design are the challenges for the purpose of the design of the publicness.

• Industrial Engineering and Management Systems
• /
• v.9 no.2
• /
• pp.157-164
• /
• 2010

The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators' productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.

• Structural Engineering and Mechanics
• /
• v.85 no.6
• /
• pp.825-835
• /
• 2023

The effective buckling length factor is an important parameter in the elastic buckling analysis of steel structures. The present article aims at developing a new method that allows the determination of the buckling factor values for frames. The novelty of the method is that it considers the interaction between the bracing and the elastic supports for asymmetrical frames in particular. The approach consists in isolating a critical column within the frame and evaluating the rotational and translational stiffness of its restraints to obtain the critical buckling load. This can be achieved by introducing, through a dimensionless parameter 𝜙_i, the effects of coupling between the axial loading and bending stiffness of the columns, on the classical stability functions. Subsequently, comparative, and parametric studies conducted on several frames are presented for assessing the influence of geometry, loading, bracing, and support conditions of the frame columns on the value of the effective buckling length factor K. The results show that the formulas recommended by different approaches can give rather inaccurate values of K, especially in the case of asymmetric frames. The expressions used refer solely to local stiffness distributions, and not to the overall behavior of the structure.

• International conference on construction engineering and project management
• /
• 2007.03a
• /
• pp.800-809
• /
• 2007

Current payment methods have many faults which are detrimental to the formation and completion of a project. This includes the use of unfair payment terms, pricing strategies and payment mechanisms between the contracting parties. This resulted in being criticised and remain in doubt, the use of current payment methods to reward good contractors and to distinguish poorly performed construction firms. In order to have an insight into this issue, a structured survey was conducted amongst UK construction practitioners. It was found that traditional pricing methods (i.e. lump sum and unit price), payment methods (i.e. interim valuation) and retention still dominate current practice. The empirical findings show that there are significant differences in the use of pricing and payment methods (when making and receiving payments) in construction. Significant differences also found in the factors affecting the choice of pricing methods when making (and receiving) construction payments. The paper concludes with analysis of the findings and future direction of research in payment systems is also provided.

• International conference on construction engineering and project management
• /
• 2015.10a
• /
• pp.477-480
• /
• 2015

Construction projects are high-risk activities. When undertaking such projects in an international setting, it can be complicated by foreign exchange (FOREX) fluctuation risk. This affects the construction business performance in various ways, namely its progress due to delays, which in turn create further problems, specifically cost overruns as a result of price increase in raw materials, disputes, arbitration, litigation and even, total abandonment. Thus, the effective management of FOREX fluctuations is crucial. Previous studies have focused on the need for contract safeguards, adequate insurance, careful planning and management, as well as foreign exchange futures hedging to address some of the risks triggered by FOREX fluctuations. An analysis of FOREX fluctuations in the international construction industry revealed that more often it was focused on project-specific issues. Currently, there is a relative lack of awareness on Organizational Capabilities (OC), the abilities that owned by the organization, which is essential in managing the impact of FOREX fluctuations. Where research has focused on OC, these are viewed in isolation. Therefore, this study attempts to close the gap by proposing a framework on managing the impact of FOREX fluctuations in the international construction industry, employing the OC perspective.

• KIEAE Journal
• /
• v.13 no.6
• /
• pp.5-16
• /
• 2013

As rapid aging society comes and people have growing interest in health, health issue has become an important value in modern society. The demand for healthy and comfortable residential environment has also increased and people themselves have made effort to build healthy residential environments. Therefore, the purpose of this study is to identify the characteristics of health housings planned and built by ordinary people. The study analyzed the contents of healthy houses that were broadcasted on TV with the title of healthy houses. Analyzed items were the planning elements and motives of building such healthy houses reflected in the samples of respective healthy houses. The result of the study revealed there were many examples of housings for healing purpose and the planning elements were in the order of architecture elements, natural elements, decoration elements, other elements and technical elements. While the experts usually put priority on technical elements for developing of healthy houses, ordinary people put priority on natural elements. This study comprehensively presents the overall characteristics of healthy houses which ordinary people pursue, on empirical basis. It is expected that this study will inspire to think about the desirable direction of healthy houses for the residents by comparing with or along with the concepts of housings that experts pursue.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.9
• /
• pp.288-297
• /
• 2018

Walking plays an important role in promoting peoples' health and reducing the increasing pressure of traffic congestion. However, for cities in developing countries located in areas with unfavorable weather, such as hot and humid weather, there is not much research on walking. Therefore, this study focuses on the walkability and the effect of the built environment on walking in the center district of Ho Chi Minh City, Vietnam. The correlation between the built environment and walking frequency of people was analyzed. Besides common elements that have been used in previous studies, other specific factors of the built environment were determined to estimate the walkability index. The results were then compared with the amount of walking obtained from surveys of local people. The result shows that people tend to walk more in the areas with a higher walkability index.

• Asian Journal of Atmospheric Environment
• /
• v.8 no.1
• /
• pp.1-14
• /
• 2014

Migration of methane ($CH_4$) gas from landfills to the surrounding environment negatively affects both humankind and the environment. It is therefore essential to develop management techniques to reduce $CH_4$ emissions from landfills to minimize global warming and to reduce the human risks associated with $CH_4$ gas migration. Oxidation of $CH_4$ in landfill cover soil is the most important strategy for $CH_4$ emissions mitigation. $CH_4$ oxidation occurs naturally in landfill cover soils due to the abundance of methanotrophic bacteria. However, the activities of these bacteria are influenced by several controlling factors. This study attempts to review the important issues associated with the $CH_4$ oxidation process in landfill cover soils. The $CH_4$ oxidation process is highly sensitive to environmental factors and cover soil properties. The comparison of various biotic system techniques indicated that each technique has unique advantages and disadvantages, and the choice of the best technique for a specific application depends on economic constraints, treatment efficiency and landfill operations.

• Journal of the Korean Solar Energy Society
• /
• v.38 no.3
• /
• pp.29-36
• /
• 2018

The goal of this study is to retrofit the windows of residential buildings and to activate the green remodeling by verifying energy saving and indoor thermal environment. As a result of analysis of the energy saving effect of 458 units window retrofits, it was possible to reduce the energy requirement by 48.20% ~ 54.97%. According to the improvement on indoor environment, it was possible to operate by reducing heating temperature and supply time. The actual gas consumption of the heating period was reduced by 25% compared with that of the window retarder to save 28,968 thousand won of heating energy cost. Resident's satisfaction surveys were conducted one year after window retrofit. More than 80% of the respondents answered that they satisfied the improvement on window performance, indoor thermal environment and indoor sound environment. As a result, we verified the energy saving effect and the improvement on the indoor environment through window retrofits.