Low loss waveguide-based Butler matrix with iris coupling control method for millimeterwave applications

This paper proposes a low loss 4×4 Butler matrix based on rectangular waveguide cavity resonators technology for millimeterwave beamforming network using iris coupling method. This method has the advantage of controlling the electrical fields and the coupling factor inside a complex medium such as waveguide cavity resonators. The coupling factor of 6 dB for 4×4 Butler matrix is achieved by tuning the iris coupling k-value between the waveguide cavity resonators. Thus, avoiding a higher phase difference losses and component losses at upper millimeterwave bands. To validate the proposed method, CST software simulations are performed under several iris coupling k-values to achieve a 6 dB coupling factor. Then, the proposed 4×4 Butler matrix is 3D metal printed using selective laser melting (SLM) technique. The measured reflection and isolation coefficients are observed below −10 dB, with coupling coefficients ranging between −6 and −7 dB. The phase differences of −42.02°, 42.02°, −130.95°, and 133.3° are achieved at the outputs. It confirmed that using this proposed method has the superiority over the conventional microstrip and waveguide coupling methods by a 1 dB coupling factor loss and a 3° phase difference error

Enhancement of Landfill Daily Cover in Minimizing the Migration of Heavy Metals in Landfill Leachate by Using Natural Soil, Pressmud Empty Fruit Bunch (EFB) in PulauBurung Landfill

This study emphasizes on the removal of heavy metals in landfill leachate by using natural soil mixed with agricultural wastes. The agricultural wastes used in this study werenatural soil or known as laterite soil, pressmud which is a waste from sugar refinery process and Empty Fruit Bunch (EFB), one of many forms of waste fromoil palm industry. The laterite soil was mixed with these wastes at different percentages of weight ratio namely 50S:40P:10E, 50S:30P:20E, 50S:25P:25E, 50S:10P:40E and 50S:20P:30E. The terms S, P and E each refers to soil, pressmud and empty fruit bunch respectively.Removal efficiency tests were also carried out and the results showed that the mixtures of laterite soil have the ability to remove concentrationsof As2+, Cd2+, Cr2+, Cu2+, Fe2+, Ni2+ and Zn2+between a range of 86% (minimum) and 99% (maximum) compared to removal via soil per se. Ergo, the laterite soil-pressmud-EFB mixtures signify great potential to be made as a daily cover material that minimizes heavy metals migration in landfill leachate, eliminates odor issues and providesadditional protection from further infiltration

Factors of Entrepreneurial Personality Characteristics on Business Failure of SMEs

The purpose of this research is to identifythefactorofentrepreneurialpersonality characteristics that can lead to the business failure of Small and Medium Enterprises (SME) in Melaka, Malaysia. This research used the Big Five Personality Model or OCEAN Model as the independent variables which include openness, conscientiousness, extraversion, agreeableness, and neuroticism. The quantitative method had been conducted by the researcher to collect the data through the questionnaire that was distributed and answered by the respondent of this research. A total of 379 Small and Medium Enterprises (SME) that established and operate in the business in Melaka, Malaysia had been participating in this data collection process. The result of the analysis showed that openness, conscientiousness, extraversion, and neuroticism have significant relationship with the factors of entrepreneurial personality characteristics on business failure of Small and Medium Enterprises (SME) in Melaka, Malaysia. There is one factor of entrepreneurial personality characteristics which is agreeableness has no significant relationship with factors of entrepreneurial personality characteristics on business failure of Small and Medium Enterprises (SME) in Melaka, Malaysia. The result of this study contributes in improve the rate of business success among SME in Melaka, Malaysia by eliminating the possibility of business failure.Keywords—Entrepreneurial personality characteristics, Big Five Personality Model, business failure, Small and Medium Enterprises (SME), Melaka.

Combating substance abuse with the potential of geographic information system combining multivariate analysis

Substance abuse problems have been a growing concern for people from all over the world. The objective of this study is to demonstrate the usefulness of a combination between a geographic information system and a multivariate analysis in substance abuse research. However, due to the limited studies on a combination of both these methods in the substance abuse field, we review some other studies in various fields indicating the potential of this method in future substance abuse studies. As the expertise of GIS lies in spatial analysis and the multivariate analysis lies in analyzing huge data thus being capable of interpreting the results very well, we hope this method will attract researchers to applying it in their studies and can consequently and indirectly help in combating substance abuse problems.Keywords: substance abuse; geographic information system; multivariate analysis;  spatial analysis; comba

3D numerical modelling of shallow tunnel in weathered granite incorporating multi-stage excavation and pre-support

Generally tunnelling in urban ground condition is not always favourable due to the tunnels’ susceptibility to major displacement especially when excavated in the soft soil and/or weak weathered rock formation. Apart from conventional support systems, pre-support measure like forepoling umbrella arch is frequently used to reinforce the ground. Modern computational tools allows the inclusion of multi-stage excavations and pre-support which was not possible in two dimensional (2D) plane strain. This paper demonstrates the three dimensional (3D) finite element analysis of Pahang-Selangor raw water transfer tunnel, as a reference case, where multi-stage excavation and pre-support are incorporated as intrinsic part of the model. The New Austrian Tunnelling Method (NATM)-3 segments which encountered Grade III weathered granite, having shallow overburden cover, was selected for numerical analysis using RS3 software. Comparison between simulated and observed data has shown good agreement during verification

Traffic burden at Skudai Toll Plaza: an analysis using complex network

One of the most important elements for the overall economic development in any country all over the world is road development. When the roads have a better interconnected network, it will help the economic activities such as trade to increase. As a country develop, the demand for efficient road transportation will get increase and highways are required to meet this increased demand. In Malaysia, the development of highway is part of government commitment to ensure economic growth of economic so that it will improve the quality of life in the society. Projek Lebuhraya Usahasama Berhad (PLUS) is one of the highway operators in Malaysia. It is also the largest highway concessionary or build–operate–transfer (BOT) operator company in Malaysia. In this paper, the traffic burden of Skudai toll plaza is studied by considering all PLUS toll plazas as a complex network. The data used is based on the number of vehicles entering from each PLUS toll plazas to Skudai and exiting from Skudai to other PLUS toll plazas. The data analysis is based on the measure of similarity among toll plazas along PLUS highway where Skudai toll plaza as the origin and destination. The interrelationships amongst toll plazas are studied by using minimum spanning tree (MST). The interpretation of MST is conducted by using centrality measures usually used in Social Network Analysis. Further, this study will provide some recommendations related to traffic highway development

Kemampuan Fertilisasi Spermatozoa Sexing dan Perkembangan Awal Embrio secara In Vitro pada Sapi

The aim of the present study was to investigate the fertilization ability of bovine oocytes and early bovine embryonic development in vitro, fertilized by frozen X and Y sperm separated by bovine serum albumin (BSA) gradient column. Oocytes were collected from slaughter house ovarian by flushing and slicing technique. Oocytes were than maturated in tissue culture medium (TCM) 199 supplemented with 10 IU/ml pregnant mare's serum gonadotropin (PMSG), 10 IU/ml human chorionic gonadotropin (hCG) and 10% fetal bovine serum (FBS) for 24 h in 5% CO2 incubator 39oC. Oocytes then fertilized with three kind of different frozen spermatozoa (X,Y and unsexing spermatozoa as control) for 14 h with final concentration 2x106 spermatozoa/mL. Embryos were cultured insynthetic oviductal fluid (SOF) supplemented with essential and non essential amino acid and 0.3% bovine serum albumin (BSA) for 96 h. Results of the experiments revealed that there was no significant difference (P>0.05) in thefertilization ability (49.17%; 51.40%; 53.42%) for X, Y and control group, respectively. No significant difference (P>0.05) in the number of embryos development (47.77%; 48.25%; 54.43%) for X, Y and control group, respectively. Furthermore, only small number of embryos could pass development blockade (23.80%; 26.08%; 23.61%) for X, Y and control spermatozoa with statistically no significant difference (P>0.05). It is concluded that sexed spermatozoa separated by BSA gradient column had comparable fertilization ability with unsexing spermatozoa and had ability to supported early embryonic development