Improvement in mechanical properties of ijuk fiber composite by using silane treatment

The rising concern towards environmental issues besides the need for more versatile polymer-based materials has led to increased interest in studying polymer composites filled with natural-fibers, usually referred to as “green” composites. However, the bonds between polymeric materials are not strong enough by referring to mechanical properties and other additional properties due to incompatibility between the polymer matrix and natural fiber filler. Thhis study tries to improveme the mechanical properties of Ijuk (Arenga pinnata) fiber filled polypropylene composite by using silane treatment. Vinyltrimethoxy silane was used for this purpose. The ijuk fiber was immersed in the silane solution before mixing with polypropylene at 10wt%, 20wt%, and 30wt%. The samples were tensile tested and their water absorption behavior was test as well. As the result, the treatment helps increasing the mechanical properties of the green composite material and decreases the percentage of water absorptio

The study of the effect of intake valve timing on engine using cylinder deactivation technique via simulation

There are many technologies that being developed to increase the efficiency of internal combustion engines as well as reducing their fuel consumption. In this paper, the main area of focus is on cylinder deactivation (CDA) technology. CDA is mostly being applied on multi cylinders engines. CDA has the advantage to improve fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6L four cylinders gasoline engine is studied. One-dimensional (1D) engine modeling work is performed to investigate the effect of intake valve strategy on engine performance with CDA. 1D engine model is constructed based on the 1.6L actual engine geometries. The model is simulated at various engine speeds at full load conditions. The simulated results show that the constructed model is well correlated to measured data. This correlated model is then used to investigate the CDA application at part load conditions. Also, the effects on the in-cylinder combustion as well as pumping losses are presented. The study shows that the effect of intake valve strategy is very significant on engine performance. Pumping losses is found to be reduced, thus improve fuel consumption and engine efficiency

Forecasting natural rubber price in Malaysia using Arima

This paper contains introduction, materials and methods, results and discussions, conclusions and references. Based on the title mentioned, high volatility of the price of natural rubber nowadays will give the significant risk to the producers, traders, consumers, and others parties involved in the production of natural rubber. To help them in making decisions, forecasting is needed to predict the price of natural rubber. The main objective of the research is to forecast the upcoming price of natural rubber by using the reliable statistical method. The data are gathered from Malaysia Rubber Board which the data are from January 2000 until December 2015. In this research, average monthly price of Standard Malaysia Rubber 20 (SMR20) will be forecast by using Box-Jenkins approach. Time series plot is used to determine the pattern of the data. The data have trend pattern which indicates the data is non-stationary data and the data need to be transformed. By using the Box-Jenkins method, the best fit model for the time series data is ARIMA (1, 1, 0) which this model satisfy all the criteria needed. Hence, ARIMA (1, 1, 0) is the best fitted model and the model will be used to forecast the average monthly price of Standard Malaysia Rubber 20 (SMR20) for twelve months ahead

Comparison of Sarcopenia Indices Based on Fall History and Level of Fear of Falling among Community-dwelling Older Adults in Selangor, Malaysia

Introduction: Sarcopenia, one of the geriatric syndromes characterized by changes in muscle mass, muscle strength and physical performance, may lead to falls in older adults. Objective: This study aimed to compare sarcopenia indices, fall history, and fear of falling (FoF) among community-dwelling older adults. Methods: : This cross-sectional study involved 201 participants (mean age = 68.45 ± 6.30 years). Fall history and FoF were recorded through assisted questionnaires and the short Fall-Efficacy Scale-international, respectively. Sarcopenia indices were measured including muscle mass (bioelectrical impedance analysis), muscle strength (JAMAR hand dynamometer), and physical performance (5-time chair stand test). Analysis of covariance (ANCOVA) was conducted to compare sarcopenia indices between fall history and FoF while controlling for age and gender. The level of statistical significance was set at p<0.05. Results: A total of 71 (35%) participants reported of a fall during the past 12 months, while approximately half of the participants demonstrated a higher concern for falls (50.2%). Those without a fall history scored significantly better in all sarcopenia indices (all p<0.05). Additionally, participants with a lower concern of falling had significantly better sarcopenia indices (p<0.05) compared to those with a greater concern of falls, except for muscle mass (p=0.052). Conclusion: Fall history and fear of falling may lead to symptoms of sarcopenia. These findings can provide evidence for promoting health education and continuous screening among older adults at risk of falls and sarcopenia

Simulation Analysis on the Potential Application of Matched Bandstop to Bandpass Filter in Filter Integrated SPDT Switch Design

This paper presents the simulation analysis on the potential application of matched bandstop to bandpass filter in filter integrated switch (FIS) design. The FIS consists of matched band-stop to bandpass filter integrated with single-pole-double-throw (SPDT) switch. The proposed design was demonstrated for 2.45 GHz applications in wireless data communication systems such as Bluetooth and Zigbee. The filter was based on L-shape lossy resonator, which can provide an absorptive feature. PIN diodes were used as switching elements for the SPDT switch and to reconfigure between band-stop and bandpass responses. Therefore, the key advantages of the proposed design are high isolation and good return loss at both ON- and OFF-state ports. As a result, the simulation showed the followings: higher than 10 dB of return loss and greater than 25 dB of isolation at the operation frequency

An Overview of Filter Integrated Switch (FIS) for RF and Microwave Applications

Integrating multiple devices into one single device is an effective method to reduce circuit size, mismatching loss, and fabrication cost. Radio frequency (RF) and microwave device integrated with filter have become a popular design concept in the recent years. In this paper, an overview of the filter integrated switch (FIS) for RF and microwave applications is presented based on previously published studies and research journals starting from 2006 until 2016. This paper also emphasizes the use of previous and current development of filter integrated switches which mainly covers the fundamental concept on the FIS, the research trends in designs and developments. At the end, this paper reports on the variety of applications that can greatly benefit from FIS and some challenges and factors that need to be considered in designing and development of filter integrated switches

Gross anatomy and ultrasonographic images of the reproductive system of the Malayan tapir (Tapirus indicus).

The Malayan tapir (Tapirus indicus) is the largest among the four tapir species and is listed as an endangered species. Ultrasound examination and description of the external anatomy of the female reproductive system of three adult females were performed, whereas the internal anatomy was investigated in necropsied samples of four adult females and one subadult female. Descriptions of the male external genitalia were conducted on one adult male. Gross examination revealed the presence of a bicornuate uterus. The uterine cervix is firm and muscular with projections towards its lumen, which is also evident on ultrasonography. The elongated and relatively small ovaries, which have a smooth surface, could not be imaged on ultrasonography, due to their anatomical position. The testes are located inside a slightly pendulous scrotum that is sparsely covered with soft, short hairs. The penis has one dorsal and two lateral penile projections just proximal to the glans penis

Quasi-static compression properties of bamboo and pvc tube reinforced polymer foam structures

In recent years, there has been a growing interest for composite materials due to the superior capability to absorb energy and lightweight factor. These properties are compatible to be utilized in the development for transportation system as it can reduce the fuel consumption and also minimize the effect of crash to the passenger. Therefore, the aim for this project is to study the compression strength and energy absorbing capability for Polyvinyl chloride (PVC) and bamboo tubes reinforced with foam. Several parameters are being considered, these being the effect of single and multiple tube reinforced foam structure, foam density, diameter of the tube as well as effect of different crosshead speed. The results showed that increasing the relative foam density will led to an increase in the compression strength and specific energy absorption (SEA) values. Furthermore, a significant increase of compression strength can be seen when several tubes are introduced into the foam while SEA remained almost the same. Finally, the influence of crosshead below 20 mm/min did not vary significantly for both compression strength and SEA

Simple preparation and characterization of bismuth ferrites nanoparticles by thermal treatment method

In the present work, nanoparticles of multiferroic bismuth ferrites (BiFeO3) were synthesized via a simple thermal treatment method. BiFeO3 was prepared from an aqueous solution containing bismuth nitrate and iron nitrate as starting materials, polyvinyl pyrrolidone (PVP) as a capping agent and nitric acid to dissolve the bismuth nitrate, respectively. It is followed by thermal treatment at various calcination temperatures at 350, 450 and 550 °C. The samples were characterized by thermogravimetric analysis, X-ray diffractometer (XRD), transmission electron microscope (TEM), vibrating sample magnetometer and electron spin resonance (ESR) spectroscopy. XRD results indicate that the samples, calcined at 350, 450 and 550 °C, crystalized in rhombohedral crystal structure (space group R3c). The crystallinity of samples increased with increasing calcination temperature. Morphology study using TEM confirmed the growth of BiFeO3 nanoparticles with the average particle’s size increases from ~30 nm up to ~80 nm with the increasing of calcination temperature from 350 to 550 °C. Magnetic saturation Ms, of samples decreased from 2.15 to 0.25 emu/g while the coercivity Hc, increased from 54.41 to 272 G when the calcination temperature increased from 350 to 550 °C. ESR revealed increment of g-factor value from 2.14 to 2.64 and peak-to-peak linewidth from 129.33 to 201.61 Oe with the increasing of calcination temperature from 350 to 550 °C. The results demonstrate that by using thermal treatment method, the BiFeO3 nanoparticles can be obtained at low temperature, i.e. 350 °C