Potential dopant in photocatalysis process for wastewater treatment-a review

Nowadays, too much pollution has happened around us, and one of them is water pollution, which each day has become more severe and worse. One of the sources of water pollution comes from the industry that has used dyes either excessively or not. In case of that, the wastewater needs to be treated before released to the river or environment. In this paper, a review of the wastewater treatment using dopants such as nitrogen and magnesium, will be discussed

Validation of requirements for transformation of an urban district to a smart city

The concept of a smart city is still debatable and yet gives attention to every country around the globe to provide their community with a better quality of life. New ideas for the development of a smart city have always evolved to enhance the quality, performance, and interactivity of services. This paper presents a model of a smart city based on the comparison of the chosen smart cities in the world and used the model to validate the requirements for the transformation of an urban district to a smart city. The proposed model for a smart city in this paper focuses on two major components, which are by utilizing IoTs (Internet of Things) in forming a model for a smart city and incorporating culture diversity. The relationship of components and culture influence are the foundation of designing the model of a smart city. In this research, the model of a smart city has been validated based on the requirements analysis from the survey instrument and the results show that the average mean of each element used is more than 4 out of 5. The model of a smart city can be used as a guideline for transformation of an urban district to a smart city

A study on the profile of solid waste and its reduction alternatives at Universiti Tun Hussein Onn Malaysia (UTHM), Pagoh Campus, Muar, Johor

Universiti Tun Hussein Onn Malaysia (UTHM) Pagoh campus is a new branch of UTHM campus situated at the Pagoh Education Hub, Johor. No studies have been conducted to determine the amount and types of waste generated in this campus, as well as the waste reduction initiatives. It is important to find out the generation and composition of waste before any recommendations for an integrated solid waste management program can be made. A mixed-method approach which comprised of quantitative and qualitative data collection was used to achieve the objectives of this research. This research revealed the results of a waste audit conducted for 10 consecutive weeks on the campus which includes the academic zone, cafeteria zone and laboratory zone. From the quantitative results, it can be summarized the average solid waste generation rate in UTHM Pagoh campus varied during regular lecture weeks, mid-semester break, and Ramadan lecture weeks, which were 203.90 kg/day, 93.96 kg/day, and 24.48 kg/day respectively. The cafeteria has been identified as the main contributor to solid waste generation on campus. The composition of the waste generated consisted of 66.9 % food waste, 19.0 % residual waste, 7.1% plastic, 4.3 % paper, 0.7 % metals, 0.7 % beverage cartons, 0.5 % aluminum, 0.6 % of other organic waste, 0.2 % of other non-organic waste and 0.1 % glass. From the qualitative data collection, the interview results revealed that the main obstacle in implementing a good SWM in the campus was the students’ and staffs’ attitude towards solid waste issues. Other challenges elaborated by the respondents include low awareness, insufficient facilities, and financial constraints. From the waste collected, it was found that a potential income of RM 330.98 could be obtained from the sales of recyclable waste. In addition, results from the cost-benefit analysis revealed that the implementation of a composting machine was found feasible to be implemented in the campus. Based on the results, proposals on the awareness campaigns, waste separation models and policy to improve the quality of SWM on the campus are provided to reduce the solid waste generated strategically

種々の表面処理を行った鉛フリーハンダ接合部の機械的性質と信頼性

Tohoku University小池淳一課

Enhancing the bearing capacity of rigid footing using limited life kenaf geotextile reinforcement

This research focuses on soft clay improvement by using Kenaf textile as a natural geotextile reinforcement. A series of small-scale laboratory tests were conducted to study the impact of the geotextile reinforcement depth, d, the vertical spacing between reinforcement, S and the number of reinfor- cement layers, N on the bearing capacity of the soil model. The test results were verified using the numerical simulation by PLAXIS 2D. In this study, the influence factors included four different d/B ratios of 0.25, 0.5, 0.75 and 1.0; three different S/B ratios of 0.25, 0.5 and 0.75, and a different number of reinforcement layers, N from 1 to 4 were investigated where B is the footing width. The results clearly showed that the bearing capacity of rigid footings was significantly improved with the Kenaf geotextile layers in the kaolin. The measured and predicted bearing capacity results were in good agreement. The optimum d/B ratio and S/B ratio, which resulted in the maximum ultimate bearing capacity of the Kenaf-reinforced model ground were about 0.25 and 0.25, respectively. The optimum N was 3, i.e., the bearing capacity insignificantly improved even with N > 3

Properties and behaviour of Pb-free solders in flip-chip scale solder interconnections

Due to pending legislations and market pressure, lead-free solders will replace Sn–Pb solders in 2006. Among the lead-free solders being studied, eutectic Sn–Ag, Sn–Cu and Sn–Ag–Cu are promising candidates and Sn–3.8Ag–0.7Cu could be the most appropriate replacement due to its overall balance of properties. In order to garner more understanding of lead-free solders and their application in flip-chip scale packages, the properties of lead free solders, including the wettability, intermetallic compound (IMC) growth and distribution, mechanical properties, reliability and corrosion resistance, were studied and are presented in this thesis. [Continues.

Deposition and application of electroless Ni–W–P under bump metallisation for high temperature lead-free solder interconnects

A reliable and robust diffusion barrier, commonly known as under bump metallisation (UBM), is indispensable in solder interconnects in order to retard the interfacial reaction rate, hence the growth of intermetallic compounds (IMCs). However, electroless Ni-P coatings are not adequate to inhibit interfacial reactions effectively since the formation of columnar structure and voids in the crystalline Ni3P layer in hybrid automotive devices (operating temperature above 300ºC) can significantly deteriorate the mechanical integrity of solder joints. In this thesis, electroless Ni-W-P coatings, as an effective UBM capable to serving under high temperature (up to 450ºC), are developed, characterised and subsequently applied onto the high temperature lead-free solder interconnects. [Continues.

Boundary layer of a dusty fluid flow over a stretching sheet

A numerical analysis has been carried out to investigate the effects of suction parameter and fluid-particle interaction parameter on boundary layer of dusty fluid towards the stretching sheet. The governing equations of boundary layer were transformed into system of coupled non-linear ordinary differential equations with the help of similarity transformation. The transformed equations then solved numerically using bvp4c solver of MATLAB software. The effects of physical parameters on velocity profile of fluid phase and dust particle phase were obtained and analysed through several plots. Useful discussion were carried out with the help of plotted graphs and tables. The numerical results obtain were compared and found to be in good agreement with the previous study. It is observed that the presence of suction increase the velocity of fluid meanwhile opposite with velocity of particle. Besides that, the fluid-particle interaction parameter increase the velocity of particle. These findings will be used for future studies involving nanofluid

The Influence of Cu on Metastable NiSn4 in Sn-3.5Ag-xCu/ENIG Joints

We have investigated the effect of small amounts of Cu on suppression of metastable bSn-NiSn4 eutectic growth in solder joints between Sn-3.5Ag-xCu solders and Ni-based substrates. For Sn-3.5Ag/electroless nickel immersion gold (ENIG) and Sn-3.5Ag/Ni solder joints we showed that the eutectic mixture contains bSn, Ag3Sn, and metastable NiSn4. It was found that addition of only 0.005 wt.% Cu to Sn-3.5Ag-xCu/ENIG or Sn-3.5Ag-xCu/Ni joints promoted formation of a stable bSn-Ni3Sn4 eutectic and that both Ni3Sn4 and NiSn4 occur in the eutectic at this Cu level. We also showed that for complete prevention of formation of metastable NiSn4 during eutectic solidification of the solder joint, addition of at least 0.3 wt.% Cu was required