Effects of Alkali-Silane Treatment on Tensile Strength of Woven Kenaf Reinforced Polypropylene Composites

Natural fibre reinforced plastics (NFRP) had been developed by researchers all over the world nowadays because natural fibre offers a lot of advantages such as low cost and does not threat the environment over glass and carbon fibres. However, limitations occur in order to produce the NFRP in mass due to the limited adhesion or bonding between the matrix and fibre which caused the reduction of their mechanical properties. The main reason behind the lack of bonding is because of their difference in nature, matrix being hydrophobic and fibre is hydrophilic in nature. Therefore, in this paper surface treatment had been done on the woven kenaf fibre. The fibre had been treated with 5% concentration of NaOH solution for 24 hour at room temperature. Then, the woven kenaf is being washed with tap water and 1% concentration of acetic acid in order to neutralise the remaining NaOH on the fibre. Then the kenaf is dried in the oven at 45oC for 12 hours. Next, the kenaf is immersed in a mixture of 5% of the fibre weight of three-aminopropyltriethoxysilane solution, 50% aqueous solution of methanol, and 1 % concentration of acetic acid for 4 hours at 28oC. The fibre is then washed and dried in the oven for another 12 hours at 45oC. The processing method used in order to produce the composite is compression moulding technique. The composites are being processed at 185oC under 10 tons of compression force. the tensile strength of the woven kenaf increased about 62% when compared to neat PP alone. However, slight decrement in tensile strength of the treated composite compared to untreated composite. Based on the FESEM analysis done, it could be seen that the decrement was due to the deterioration of the woven kenaf fibre maybe because being damp for too long

Strategies to Minimise the Impact of COVID-19 on the Construction Industry: A Case Study of Construction Site Clusters in Malaysia

Malaysia has seen the third wave of infection since the start of the global COVID-19 pandemic, with approximately 103 construction sites involving over 14,667 workers reported from April 2020 to February 2021. This has led to limited progress in construction projects or a complete halt, resulting in late project delivery. The purpose of this paper is to investigate the factors influencing the spread of COVID-19 and the strategies taken by the affected construction sites to mitigate the spread of the outbreak. The researchers adopted a case study approach with a multiple-case design and discusses the use of an in-depth interviewing method to collect rich data on the studied phenomenon. Data were collected from three construction sites. The sites were mixed development projects in nature and provided in-depth, rigorous, and robust information. Based on the results, two categories of factors influencing the spread of COVID-19 were established. These are primary and secondary factors, such as workers’ mobilisation, uncontrolled movement of workers, and the limited practice of social distancing. Furthermore, evidence suggests that the strategies adopted to control the effects of the pandemic were a combination of government enforcement and initiatives taken by construction companies. This paper concludes that an early identification of the causes of the spread will enable appropriate implementation strategies to control the outbreak. This study is an attempt to present the experiences of one developing country as an example of a means of dealing with unexpected pandemics or other intractable diseases that can affect project delivery

Challenges of sustaining urban water supply for rapidly growing post war city: case study of Hargeisa City

Over 65% of the estimated one million people in Somaliland capital city of Hargeisa are currently relying on water trucking from unprotected and poorly maintained water sources around Hargeisa for daily water use and the poorest families spend almost 5 times more than others who have access to main water due to the high price of the trucked water. Hence, the Hargeisa urban water supply upgrading project is currently underway to replace the tumbledown and inadequate water infrastructure that was constructed 1970s to supply what was a city of 180,000 inhabitants. The project is principally funded by the European Union with supplementary fund from the Somaliland Development Fund and World Bank/WSP in partnership with the Hargeisa Water Agency and UN- Habitat. Therefore, this paper is examining the challenges that the poor resourced Hargeisa Water Agency (HWA) will face for managing the improved Hargeisa water supply system beyond the current large-scale water supply upgrading project

Interspecific isozyme variability in Porcellanid crabs (Crustacea: Decapoda: Anomura) from the coastal waters of Pakistan

Polyacrylamide gel electrophoresis was used to investigate the interspecific isozyme variability among three species of Porcellanid crabs: Petrolisthes ornatus, P. rufescens and P. boscii from the coastal waters of Karachi, Pakistan. Seven enzyme systems and the general protein (non-specific) were examined for genetic variations. Among the three species; Nei's heterozygosity for overall loci was observed (0.067), whereas Shannon’s information Index (I) for genetic variations based on the heterozygosity was (0.055) in three species of Genus Petrolisthes. Species were differentiated from each other as Nei’s genetic distance ranged in between 0.0093- 0.0314. The genetic relationship among the three species of genus Petrolisthes similar from those inferred from morphological features

Stress Distribution in Photoelastic Models of Transverse Sections of Porcelain-Fused-to-Gold Crowns and Preparations

The stress distribution in composite photoelastic models of transverse sections of porcelain-fused-to-gold restorations and preparations was determined. The optimum design was one in which the porcelain-gold junction was on the lingual side of contact points that represented the contact of adjacent teeth.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68216/2/10.1177_00220345730520051201.pd

Effects of Alkali-Silane Treatment on Tensile Strength of Woven Kenaf Reinforced Polypropylene Composites

Natural fibre reinforced plastics (NFRP) had been developed by researchers all over the world nowadays because natural fibre offers a lot of advantages such as low cost and does not threat the environment over glass and carbon fibres. However, limitations occur in order to produce the NFRP in mass due to the limited adhesion or bonding between the matrix and fibre which caused the reduction of their mechanical properties. The main reason behind the lack of bonding is because of their difference in nature, matrix being hydrophobic and fibre is hydrophilic in nature. Therefore, in this paper surface treatment had been done on the woven kenaf fibre. The fibre had been treated with 5% concentration of NaOH solution for 24 hour at room temperature. Then, the woven kenaf is being washed with tap water and 1% concentration of acetic acid in order to neutralise the remaining NaOH on the fibre. Then the kenaf is dried in the oven at 45oC for 12 hours. Next, the kenaf is immersed in a mixture of 5% of the fibre weight of three-aminopropyltriethoxysilane solution, 50% aqueous solution of methanol, and 1 % concentration of acetic acid for 4 hours at 28oC. The fibre is then washed and dried in the oven for another 12 hours at 45oC. The processing method used in order to produce the composite is compression moulding technique. The composites are being processed at 185oC under 10 tons of compression force. the tensile strength of the woven kenaf increased about 62% when compared to neat PP alone. However, slight decrement in tensile strength of the treated composite compared to untreated composite. Based on the FESEM analysis done, it could be seen that the decrement was due to the deterioration of the woven kenaf fibre maybe because being damp for too long

Coinfection with Lichtheimia corymbifera and Aspergillus flavus in an Immune-Competent Patient Mimicking as Pulmonary-Renal Syndrome

Lichtheimia corymbifera and Aspergillus flavus pulmonary coinfection has been rarely reported in immune-competent patients. We report case of a young male who presented with clinical features of pulmonary-renal syndrome and was later diagnosed to have bilateral polymicrobial fungal lung infection

Effects of temperature and airflow on volume development during baking and its influence on quality of cake

Volume and texture of cake are among the important parameters in measuring the quality of cake. The processing conditions play important roles in producing cakes of good quality. Recent studies focused more on the formulation and the manipulation of baking temperature, humidity and time instead of airflow condition. The objective of this study was to evaluate the effects of baking temperature and airflow on the volume development of cake and final cake quality such as volume development, firmness, springiness and moisture content. The cake was baked at three different temperatures (160°C, 170°C, and 180°C), and two different airflow conditions. Baking time, height changes of batter, texture and moisture content of cake were compared to identify the differences or similarities on the final product as the process conditions varied. Results showed that, airflow has more significant effects towards the product quality compared to baking temperature especially on baking time which was 25.58 - 45.16%, and the rate of height changes which was 0.7 mm/min. However, different baking temperatures had more significant effects towards volume expansion which was 2.86 - 8.37% and the springiness of cake which was 3.44% compared to airflow conditions

Effect of sodium caseinate concentration and sonication amplitude on the stability and physical characteristics of homogenized coconut milk

The ultrasonic homogenization of coconut milk with added sodium caseinate (SC) was carried out to reduce the fat globules size and stabilize the emulsion. The coconut milk was mixed with SC at different concentrations from 0.5% to 2% w/w. The sonication was conducted at different sonication amplitudes (60%, 80% and 100%). The primary and effective droplet size, viscosity, homogenization efficiency and free fat content of the homogenized emulsion were characterized. Ultrasonic homogenization significantly reduced the average particle size to lower than half of its original size and reached to sub‐micron range size. Increasing the SC concentration positively reduced both the creaming index and free fat content without significant change in apparent viscosity. In this study, the changes in the physical characteristics of the emulsion were more affected by the SC concentration than the amplitude setting percentage. Nevertheless, both parameters were important in the formation of submicron‐sized droplets

Evaluation on safety and sensory analysis of xylitol substituted dadih

Dadih is a favourable dessert in South East Asia due to its appealing sweet taste and jellies appearance. The sweet taste is from sugar (sucrose) content, and in order to reduce the sucrose, it was substituted with xylitol. Xylitol can provides intense sweetness with less calories and lower water activity, which potentially contribute to higher microbial stability thus giving longer shelf life. The objective of this study was to evaluate the effect of xylitol substituted on dadih safety and sensory qualities. Dadih was prepared by replacing sucrose with xylitol composition in the range of 0 – 100% and at two levels of cooking times (15 and 20 minutes). Safety analysis were performed using total plate count (TPC) and water activity (aw) analysis. For sensory analysis, seven attributes were evaluated (appearance, colour, hardness, elasticity, taste, sweetness, and overall acceptability) based on the 9-hedonic scale. From the findings, dadih samples with total sucrose (0%) were observed to be contaminated faster compared to total xylitol (100%). Dadih with xylitol is more stable with prolonged shelf life. From sensory analysis, dadih sample prepared with shorter cooking time (15 minutes) was selected as more favourable with overall acceptability score between 72 - 85%. More than 70% of the score for dadih with xylitol substitute was above ‘slightly like’, which indicates a promising future to produce xylitol substitute dadih. The outcome of this study has shown that xylitol is potentially to be utilize as sugar substitute for dadih production