Optimization of injection molding parameter of ti-6al-4v powder mix with palm stearin and polyethylene for the highest green strength by using taguchi method

This paper present the Taguchi method of L27 (313) orthogonal array as a tool in optimization of Metal injection molding (MIM) parameters for the highest green strength. Injection pressure, injection temperature, powder loading, mold temperature, holding pressure and injection speed are Parameters to be optimized. Besides those, interaction of the injection pressure, injection temperature and powder loading were studied. The metal powder of Ti-6Al-4V is mixed with binder 60wt% of palm stearin and 40wt% of polyethylene successfully injected at optimum parameter condition: 350 bar of injection pressure, 140oc of injection temperature, 65vol% of powder loading, 50oc of mold temperature, 600 bar of holding pressure, and 10ccm/s of the injection rate. Analysis of variance (ANOVA) for the best signal to noise ratio (S/N) presents the contribution of the parameters to the quality characteristic (green strength). Results show that the mold temperature has highest significant percentage (27.59%) followed by powder loading (15.44%) and injection pressure (12.30%) Nevertheless, the analysis of variance does not show any contribution from interaction

Forecasting wind speed data by using a combination of ARIMA model with single exponential smoothing

Wind serves as natural resources as the solution to minimize global warming and has been commonly used to produce electricity. Because of their uncontrollable wind characteristics, wind speed forecasting is considered one of the best challenges in developing power generation. The Autoregressive Integrated Moving Average (ARIMA), Simple Exponential Smoothing (SES) and a hybrid model combination of ARIMA and SES will be used in this study to predict the wind speed. The mean absolute percentage error (MAPE) and the root mean square error (RMSE) are used as measurement of efficiency. The hybrid model provides a positive outcome for predicting wind speed compare to the single model of ARIMA and SES

Critical gap analysis of merging sections at Kuala Lumpur middle ring road

At merging sections, drivers normally slow down and sometimes need to stop while seeking a suitable gap before merging with the mainstream. Thus, there will always be several observed rejected gaps and an accepted gap which can be used to determine the smallest average gap, so-called critical gap. This study was carried out to determine critical gap values at selected merging sections at the Jalan Tun Razak and the DUKE Expressway uses the Maximum Likelihood method. Data were collected by using videotaping method and the gap acceptance data were extracted for analysis. A gap acceptance event at highway merging sections in this study was redefined due to unavailability of stopping vehicles at the ramp junction. Therefore, the gap data were estimated starting from a ramp’s vehicle passing the end of gore marking to where it merges with the mainstream. The analysis of the critical gap takes into consideration accepted gaps greater than 5 seconds to avoid forced entry due to lead impedance of successive vehicles on mainstream. The critical gap values obtained in this study, according to vehicle classification were ranged between 4.5 to 5.0 seconds, which are slightly smaller if compared to critical gap values for particularly left turn from minor movement at priority junction of the Arahan Teknik (Jalan) 11/87 and the United States Highway Capacity Manual 2000. The findings shall help to study driving behavior of local drivers, especially at priority control facilities such as merging sections

Broadcast Control of Multi-Agent Systems for Assembling at Unspecified Point with Collision Avoidance

This paper presents a broadcast control problem for multi-agent systems to perform a motion-coordination i.e. assembling tasks without colliding into each other. In this paper, we use potential energy function for the collision avoidance where the agents will move away from the neighbor agents if they are reaching certain distance. In the simulation, the results show that the agents are successfully achieving the assembling task without colliding into each other

Pengembangan Instrumen Tingkat Keterlaksanaan Penilaian Otentik pada Pembelajaran Fisika Berbasis Kurikulum 2013 di Kelas X SMA Negeri Se-kota Pekanbaru

This study aims to determine the Vailidity of the Authentic Curriculum Based Curriculum 2013 in the eyes of the High School Physics subjects that are developed to support the level of implementation of Authentic School Assessment that includes attitude, knowledge, skills and authentic assessment. The type of research used is R & D (Research and Development). Development of Authentic assessment instruments includes preliminary studies, instrument planning, instrument development, instrument validation, and end products. The authentic assessment instrument developed in this research is a questionnaire that contains closed questions or open questions. From the results of the large index validation for attitude assessment 3.15, knowledge assessment 3.27, skill assessment 3.10, and authentic assessment step 3.4. Overall, the validation index of 3.21 categories is obtained. Thus it can be concluded that the authentic assessment instruments of high school students for physics subjects that have been developed are valid or fit to be used in analyzing the level of implementation of Authentic assessment of schools in applying attitude, knowledge, skills based on curriculum 2013

Aerobic granulation for real domestic sewage treatment at hot and low humidity climate condition

With inoculum sludge from a conventional activated sludge wastewater treatment plant, a sequencing batch reactor fed with real domestic wastewater was operated at 50 ± 1 °C to study the formation of aerobic granular sludge (AGS) for simultaneous organics and nutrients removal with a complete cycle time of 3 h. The AGS were successfully cultivated with excellent settling ability and demonstrated exceptional performance in the organics and nutrients removal with influent loading rate of 1.2 kg COD m-3 d-1. Stable, regular, dense and fast settling granule (average diameter, 2.0 mm and sludge volume index, 73.501 mL g-1) were developed in a single reactor. In addition, 89 % COD removal efficiency was observed in the system at the maturation stage of the granulation, while its ammonia nitrogen removal efficiencies were up to 99 %. The study demonstrated the capabilities of AGS formation in a single, high and slender column type-bioreactor at high temperature which is suitable to be applied for hot climate and low humidity condition (e.g. Saudi Arabia)

Work-related injuries among physiotherapists in public hospitals—a Southeast Asian picture

OBJECTIVES: A cross-sectional study was conducted to measure the prevalence of work-related injuries among physiotherapists in Malaysia and to explore the influence of factors such as gender, body mass index, years of work experience and clinical placement areas on the occurrence of work-related musculoskeletal disorders. METHODS: Self-administered questionnaires adapted from the Nordic Musculoskeletal Questionnaire were sent to 105 physiotherapists at three main public hospitals in Kuala Lumpur, Malaysia. The questionnaire had 12 items that covered demographic information, areas of musculoskeletal problems and physiotherapy techniques that could contribute to work-related musculoskeletal disorders. The data obtained were analyzed using the Statistical Package for Social Science version 14 software. RESULTS: The overall prevalence of work-related injuries during the past 12 months was 71.6%. Female therapists reported a significantly higher prevalence of work-related musculoskeletal disorders than the male therapists (73.0%, p,0.001). Significant differences were observed between the proportion of therapists who had work-related musculoskeletal disorders and those who did not for the group with a body mass index (BMI) .25 (x ² = 9.0, p = 0.003) and the group with a BMI of 18-25 (x ² = 7.8, p = 0.006). Manual therapy (58.6%) and lifting/transfer tasks (41.3%) were the two physiotherapy techniques that most often contributed to work-related musculoskeletal disorders. CONCLUSION: Work-related injuries are significantly higher among the physiotherapists in Malaysia compared with many other countries. Female therapists reported a higher incidence of work-related musculoskeletal disorders in this study, and work-related musculoskeletal disorders were more common among therapists working in the pediatric specialty. This study contributes to the understanding of work-related disorders among physiotherapists from a southeast Asian perspective where the profession is in its development stage

Study on the Use of Micro-Perforated Panel to Improve Acoustic Performance in Mosque

Most activities in mosque such as Friday prayer and the sermon by an Imam require clarity of speech. Unfortunately, this ‘speech intelligibility’ performance is often poor due toinitial design of a mosque. This paper presents assessment of the indoor acoustics of a mosque. Acoustical properties such as reverberation time, clarity and early decay time are obtained from simulation data using CATT indoor acoustic software. The studystarted with anempty mosque with no acoustic treatment. Acoustic ‘green’ absorbers using micro-perforated panel (MPP) are then introduced to improve the acoustic performance. The application of MPP is still rare for mosque and is expected to replace the typical porous absorber. The effect of the panel size, location and frequency range of sound absorption are simulated and the results are discussed