Study of using three dimensional printer for EDM electrode fabrication

In this study, Cu-Al2O3 powder was prepared using ball mill and used separately for powder metallurgy (PM) and Three Dimensional Printer (3DP) application to fabricate electrode for electrical discharge machining (EDM). The materials in powder form were analyzed under scanning electron microscope (SEM) and particle size analyzer (PSA) to ensure that they fulfill the requirement for each fabrication method. For PM process, five compositions of Cu-%wt Al2O3 powder were prepared ranging from 0% to 20% Al2O3 contents at 5% increment. The powder were compacted and sintered in argon protected atmosphere to determine the suitable compaction pressure and sintering temperature to fabricate PM electrode. Microscopic analysis revealed that 48MPa and 921°C is the best compaction pressure and sintering temperature respectively for EDM electrode fabrication. EDM electrode samples were fabricated using both recommended parameters, and were tested to erode JIS SKD11 (mould steel) workpiece for 5 minutes, with solid Cu electrode as the benchmark. Electrodes’ performances were assessed by calculating the tool wear rate (TWR), material removal rate (MRR) and by measuring the average surface roughness (Ra) of the eroded cavity. From the experiment conducted, the PM electrodes are not as good as solid Cu electrode in terms of MRR, but the addition of Al2O3 at around 10%wt could reduce the TWR and Ra. The composition of Cu-10%wt Al2O3 powder electrode that has the optimum machining results was then prepared for 3DP application. Green parts were fabricated using 3DP, sintered and infiltrated prior to being tested at EDM machine. Although sintering was a success, samples were still porous due to the failure in infiltration process. The performance of EDM electrodes fabricated using 3DP were evaluated the same way as the ones fabricated via PM process. Experiments using 3DP electrodes showed that the electrodes depleted and became the alloying element on the workpiece. Further studies are needed on the sintering and infiltration method in order to improve the quality of the electrode fabricated using 3DP

NEW GREEN TECHNOLOGIES FOR ORGANOCATALYTIC ASYMMETRIC EPOXIDATION APPLICATIONS IN SYNTHESIS

This thesis describes the application of asymmetric epoxidation reactions on chromene substrates mediated by Page’s iminium salt catalysts. Organocatalytic asymmetric epoxidation is an efficient tool to access enantiomerically rich epoxides. This study is divided into three main parts which are discussed in each chapter. The first part of this research is the preparation of iminium salt catalysts followed by synthesis of several chromene substrates. The final part is the application of the asymmetric epoxidation of the readily prepared iminium salts on chromene substrates. The first chapter reviews brief introduction and historical background of organocatalysis, chromene substrates and asymmetric epoxidation reactions. Towards the end of the chapter, several examples are described of past and current development of asymmetric epoxidation by organocatalysts. In the last part of Chapter 1, the discussion focuses on asymmetric epoxidation on chromene substrates. Chapter 2 discusses the preparation of Page’s iminium salts and improvement of previous methods followed by several approaches to synthesis of chromene substrates. The final part is discussing application of asymmetric epoxidation using synthesized iminium salts on the chromene substrates. Excellent enantioselectivities were observed in nonaqueous condition using TPPP as oxidant for 6-cyano-2,2’-dimethylchromene giving ee >99% while reactions under aqueous conditions afforded the corresponding diol giving ees as high as 71%. In Chapter 3, experimental procedures and data for all the compounds synthesized are included. Appendices contain HPLC trace data, NMR and IR data of several compounds

A Taxonomy for Congestion Control Algorithms in Vehicular Ad Hoc Networks

One of the main criteria in Vehicular Ad hoc Networks (VANETs) that has attracted the researchers' consideration is congestion control. Accordingly, many algorithms have been proposed to alleviate the congestion problem, although it is hard to find an appropriate algorithm for applications and safety messages among them. Safety messages encompass beacons and event-driven messages. Delay and reliability are essential requirements for event-driven messages. In crowded networks where beacon messages are broadcasted at a high number of frequencies by many vehicles, the Control Channel (CCH), which used for beacons sending, will be easily congested. On the other hand, to guarantee the reliability and timely delivery of event-driven messages, having a congestion free control channel is a necessity. Thus, consideration of this study is given to find a solution for the congestion problem in VANETs by taking a comprehensive look at the existent congestion control algorithms. In addition, the taxonomy for congestion control algorithms in VANETs is presented based on three classes, namely, proactive, reactive and hybrid. Finally, we have found the criteria in which fulfill prerequisite of a good congestion control algorithm

Session Initiation Protocol Attacks and Challenges

In recent years, Session Initiation Protocol (SIP) has become widely used in current internet protocols. It is a text-based protocol much like Hyper Text Transport Protocol (HTTP) and Simple Mail Transport Protocol (SMTP). SIP is a strong enough signaling protocol on the internet for establishing, maintaining, and terminating session. In this paper the areas of security and attacks in SIP are discussed. We consider attacks from diverse related perspectives. The authentication schemes are compared, the representative existing solutions are highlighted, and several remaining research challenges are identified. Finally, the taxonomy of SIP threat will be presented

Family-friendly benefits and job satisfaction: A case study of women employees in software company, Kulim

The purpose of this study is to investigate on the family-friendly benefits such as flexible work arrangements, family care benefits, child care facilities and benefits, and also managerial support towards employees’ job performance. A survey of a representative sample of 275 respondents was used in this study. A quantitative method was used in this study by distributing the questionnaires to the respondents. The data from the questionnaires then were analyzed by using Statistical Package for Social Science (SPSS) version 25.0. Descriptive analysis was conducted to ascertain data normality as well as to analyze frequencies of respondents’ demographic profile. Multiple regression analyses were performed to test the hypotheses of the study. Based on the results, all of the independent variables have significant relationship with job performance. Finally, there were several recommendations and directions for future research discussed in this study

Preparation of Vocational College Graduates as Skilled Workforce in the Local Construction Industry

Construction industry is growing rapidly along with the development of a country. This situation caused a high demand of workforce in this industry until the hiring of foreign workers becomes a necessity, as seen in Malaysia’s scenario. To overcome this issue, the government of Malaysia established many Technical and Vocational Education and Training (TVET) institutes that have potential to produce local workforce as highly skilled workers in construction industry. However, the preparation of these institutes for their students have never been analyzed, as the involvement of students from TVET institutes in local construction industry as skilled workers is still low, making their preparation method as an issue. Therefore, this research will identify the types of preparation method by TVET institutes for students pursuing programmes related to construction industry, and to assess teaching strategies for programmes related to construction industry to improve student preparation to become skilled workforce. To achieve the main objectives of this research, data collection is performed by interviewing teachers from three Vocational Colleges (VC) namely VC Kluang, VC Klang and VC Taiping, which are teaching Construction Technology programmes. It can be concluded that VCs have adequate preparation to produce graduates that can become skilled workforce in the construction industry. The results conclude that there are two types of preparation method made by the VCs; preparation method in the classroom and preparation method outside the classroom. The classroom preparation method includes laboratory training and teaching using modules designed to fit industrial needs. The results from outside classroom preparation include extra-curricular activities and construction site visits. As for results of the second objective, the teaching strategies to improve student preparation for skilled workforce is through the emphasis of safety during construction to students and the raising of student interest in Construction Technology programmes through industry participation. However, actions need to be taken in order to solve the issues that include a lack of equipment and no large area for computers. This study can help VCs to enhance the student preparedness to work in the construction industry

Cloud computing: Use and impact of technology

The objectives of this study are to identify the current state of cloud computing use and to examine the impact of its use to the small and medium enterprises (SMEs) in Malaysia.The impact of cloud computing use is examined from three dimensions: strategic benefits, informational benefits, and security enhancement.Data are collected through a survey of senior managers of the SMEs.The findings suggest that all of the cloudbased technologies are currently in use. The use of cloud computing in the organization facilitates informational and strategic benefits, but not security enhancement

Portrayal of Women in National and International Advertisements in Pakistani Magazines: Why Need to Rethink

This research examines the portrayal of women in the national and international advertisements of Pakistani leading magazines “The Mag” to explores that how women are presented in advertisement of print media. Four main categories regarding women portrayal with sub categories were used to apprehend the interpretation of the portrayal of the women by adopting comparative approach towards the national and international advertisements. The content analysis of the advertisements in the leading magazine is conducted to analyze the glamour, seductive smile and wearing short dresses in the advertisement to comprehend the portrayal of the women. Findings suggests that in Pakistani magazines women are used as decoratively through glamour look they are presented with glossy makeup and attractive hairstyle with flashy lights on their face in magazines. Outcomes of the comparative analysis indicates that the national advertisements in the female magazines are presenting women with more seductive and facial expressions appeals. Keywords: Advertisements, Respective, submissive, serious, smiling, seductive, with man, alone, full eastern dresses, short western dresses, natural makeup, heavy.

Implementation of Wireless Body Area Network Based Patient Monitoring System

WBAN has gained considerable attention and became an emerging technology at health services due to its wide range of utilities and important role to improve the human health. The proposed system consists of different components, Pulse rate sensor which uses the optical technology to detect the flow of blood. Temperature sensor is used to measure the temperature from the body. Peripheral hemoglobin oxygen saturation (SpO2), blood pressure and electrocardiogram (ECG) are measured by the nurses. Radio Frequency Identification (RFID) reader with passive tags is used to identify the patient. Arduino UNO microcontroller is used for data processing. The patient parameters are transmitted via Bluetooth technology to the base station. The base station which is Raspberry Pi (RPi) B model 3 used to receive the collected data and acts as the web server, so the physician accesses RPi to display different information. The obtained results from different cases prove the high performance of the system and sensor nodes that are designed. The overall system operates within different environments conditions. If one sensor node is fall down, the other nodes are still operate and do not affect. Also we improve the speed of the system response. The usage of wireless communication to send the data instead of the wired one as it provides a greater mobility to the device. The cost is also minimized by utilizing the feature of sending multiple parameters via a single node. Keywords: Wireless Sensor Network (WSN), Patient Monitoring, Biomedical, sensors, Microcontroller, Arduino, Raspberry Pi.

Establishing a strategic framework of green procurement for the malaysian construction industry / Mohd Sallehuddin Mat Noor and Fadzil Hassan

Resource depletion has become the main issues in the last decades. The fact that world population increased into 7 billion in the year 2013, natural resources has become a crucial element in creating better quality of life through physical infrastructure development. In order to decrease the emission of carbon up to 20 percent in the year 2020, green procurement is believed to be one of the solution minimize the environmental impact through its nature of procuring service or product which can be controlled from the initiation steps until its demolition. The current problem in Malaysian construction industry is that it is at the junction in determining the growth of this sector. Megatrend in the global scale had influenced it through risk management, sustaining profitability, sustaining corporate social responsibility and growing bureaucracy, green procurement is believed to be the solution to the construction industry to grow steadily thus contributes to the nation’s economic and social growth. Most of the data that will be obtained are primary data, using document analysis, questionnaire and focus group that will be conducted to the respective bodies in construction industries. This research will be detailed up on its elements and the sub elements of the strategic framework within each element. It also will be tested in the real construction industry. Finally, this strategic framework will be validated to be used in the current industry. The anticipated finding is that to fill the knowledge gap by introducing a green procurement strategic framework for the industry restructuring a new type of procurement method