Bioremediation a potential approach for soil contaminated with polycyclic aromatic hydrocarbons: An Overview

Polycyclic aromatic hydrocarbons (PAHs) represent a group of priority pollutants which are present at high concentration in soils of many industrially contaminated sites. Standards and criteria for the remediation of soils contaminated with PAHs vary widely between countries. Bioremediation has gained preference as a technology for remediation contaminated sites as it is less expensive and more environmental friendly. Bioremediation utilizes microorganisms to degrade PAHs to less toxic compounds. This technology degrades contaminants through natural biodegradation mechanisms or enhanced biodegradation mechanism and can be performed in-situ or ex-situ under aerobic or anaerobic conditions. The purpose of this paper is to highlight potential of using isolated strains from municipal sludge on soil remediation. Several indigenous bacteria from municipal sludge namely genus Micrococus, Sphingomonas, and Corynebacterium demonstrated a high removal rate of PAHs with more than 80% of lower molecular weight of PAHs degraded after one week incubation. Laboratory studies had established that these genus able to degrade PAHs on contaminated soil. The successful application of bacteria to the bioremediation of PAHs contaminated sites requires a deeper understanding of how microbial PAH degradation proceeds. An overview of research focusing on biodegradation of PAHs will be presented

Radio Access Technology (RAT) selection mechanism using TOPSIS method in Heterogeneous Wireless Networks (HWN)

In next-generation wireless networks, a Multi-Mode Device (MMD) can be connected with available Radio Access Technology (RAT) in a Heterogeneous Wireless Network (HWN). The appropriate RAT selection is essential to achieve expected Quality of Service (QoS) in HWN. There are many factors to select an appropriate RAT in HWN including Data rate, Power consumption, Security, Network delay, Service price, etc. Nowadays, the MMDs are capable to handle with multiple types of services like voice, file downloading, video streaming. Considering numerous factors and multiple types of services, it is a great challenge for MMDs to select the appropriate RAT. A Multi-Attribute Decision Making (MADM) method to deal with numerous attributes to achieve the expected goal is Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). This research utilized TOPSIS method to evaluate its proposed algorithm to choose the proper RAT for single and dual call services. The algorithm applies users' preference of a specific RAT that varies for diverse categories of calls. It also aggregates the assigned call weight and call priority to choose the RAT for group call admission for different scenarios. The highest closeness coefficient has been considered the appropriate networks among other networks. 100 call admission into three networks has been simulated and has been observed

Game theory for resource allocation in heterogeneous wireless networks - a review

In next-generation wireless networks, a user can be connected through MultiMode Device (MMD) to the multiple wireless networks in Heterogeneous Wireless Networks (HWN) considering several factors; including network technology, data service type, available bandwidth, Quality of Service (QoS), monetary cost, etc. To deal with all these multi attributes, game theory based models have been used to point out a better solution. This paper evaluates the techniques, methods, advantages, limitations of some game theory-based models for wireless resource allocation in HWN. Finally, it concludes that the Shapley Value method can be used for further research activities for its efficiency

A comprehensive analysis of improving the QoS of IMM traffic for high speed wireless campus network

Interactive Multimedia (IMM) applications such as voice and video conferencing are very important in our learning environment. They offer useful services that benefit its users but these services suffers performance degradation from today’s high speed Wireless Local Area Network (WLAN). However, guaranteed Quality of Service (QoS) remains the bottleneck in the network which becomes a great challenge in attempting to improve its performance. This work reviewed many approaches and considers mapping QoS class parameters such as Quality of Service Class Identifier (QCI), Maximum Bit Rate (MBR) and Allocation and Retention Priority (ARP) to the upstream and downstream data flowing in the network as an attempt to improve its performance. Priority is then given to the QoS bearer packets by associating Differentiated Services Code Point (DSCP). A comprehensive analysis of QoS in different protocols in wireless networks has been studied. Open issues and research directions have been addressed with a proposed mechanism to enhance the QoS of the wireless networ

Audit of newborn screening programme for congenital hypothyroidism

Congenital hypothyroidism screening programme in Universiti Sains Malaysia (USM) was started since 2004 using cord blood TSH. An audit of the screening programme for a period of 24 months was done for the year 2010 and 2011. A total of 12928 newborn babies were screened with coverage of 100%. Two cases were confirmed to have primary congenital hypothyroidism. The mean recall rate was 2.31% and the mean sample rejection rate was 1.59%. The subject response for the repeat test was 63% for the year 2010 and 78% for the year 2011. Continuous surveillance is important to ensure the National Quality Assurance (QA) were met

Survey on occurrence of aflatoxins in chicken feeds from Peninsular Malaysia

This study was conducted to observe the occurrence of aflatoxin in chicken feed from Peninsular Malaysia. A total of 336 samples of chicken feed from Peninsular Malaysia were conveniently collected in this survey. The chicken feed represented the following three categories which are starter, grower and finisher. All samples were collected from local poultry farms in East Coast Region (Kelantan, Terengganu, and Pahang), Northern Region (Perlis, Kedah, Penang, and Perak), Southern Region (Malacca, Johor) and Central Region (Selangor, Negeri Sembilan) of Peninsular Malaysia for a period of six months (July-December 2015). Enzyme-linked immunosorbent assay (ELISA) was used for screening of total aflatoxin (TA) in the samples. High performance liquid chromatography (HPLC) with fluorescence detector was used for determination of aflatoxin B and G. Moisture content of samples was determined using the hot air oven method (AOAC International, 2011). Overall, the incidence of positive TA > 20 μg/kg in chicken feed is 14.9% (50 samples). The average level of TA was found significantly different between different states at p<0.05 for both broiler grower and finisher. The chromatograph results showed that positive samples were found in broiler finisher from Kedah (94.6 μg/kg and 42.1 μg/kg) and Penang (56.4 μg/kg) with aflatoxin B1. In this study, the range of moisture content were around 6.5-27.3%. About 40% samples have more than 12% moisture content. One of the predisposing factors for aflatoxin accumulation in chicken feed is moisture content. The results warrant the need for surveillance and constant monitoring programmes for the prevention of aflatoxin incidence in poultry farms

Effect of curing time on physical and mechanical properties of phenolic-treated bamboo strips

Effect of pressing time on physical and mechanical properties of phenolic-impregnated bamboo strips was evaluated. Bamboo strips (Gigantochloa scortechinii) were impregnated with low molecular weight phenol formaldehyde (LMwPF) resin. Samples were submerged in LMwPF resin using a vacuum chamber of 750 mmHg for 1 h before it was released within 1.5 h. Treated strips were dried in an oven with a temperature of 60 °C within 6-9 h. It was hot pressed at 14 kg m-2 and a temperature of 140 °C for 5, 8, 11, 14 and 17 min. The physical and mechanical properties of the test indicated that the properties of phenolic-treated strips have significantly increased as compared to control samples. Dimensional stability (water absorption, thickness swelling and linear expansion) of the phenolic-treated properties were significantly lower than control after 5-min pressing time. The antishrink efficiency (ASE) of phenolic-treated strips increased when pressing time were extended from 5 to 17 min. The mean value of modulus of rupture (MOR) for the control samples (177 N mm-2) showed a significant difference with phenolic-treated strips after 17-min pressing time (224 N mm-2). However, there is no significant difference in compression parallel to grain. The MOE of phenolic-treated strips was 21,777 N mm-2 and for control was 18,249 N mm-2, whereas the compression parallel to grain values for phenolic-treated and control samples were 94 and at 77 N mm-2, respectively

Prediction of maximum spreading time of water droplet during impact onto hot surface beyond the Leidenfrost temperature

When a water droplet impacts on a heated surface in the film boiling regime, it will spread, recede, and finally bounce off from the heated surface. These unique liquid-solid interactions only occur at high surface temperatures. Our main objective in this research is to measure the maximum spreading and residence time of the droplet and the findings were compared to theory. We focused our study in the film boiling regime. Brass material was selected as the test surface and was polished until it became a mirror polished surface. The temperature range for this experimental work was between 100 ◦C up to 420 ◦C. Degassed and distilled water was used as the test liquid. The high speed video camera recorded the images at the rate of 10,000 frames per second (fps). As a result, it was found that the experimental value of maximum spreading and esidence time agreed closely with the theoretical calculation. A new empirical formula that can be used to predict the maximum spreading time in the film boiling regime is also proposed

Determination of in vitro antidiabetic effects of Zingiber officinale Roscoe

Aqueous extracts of Zingiber officinale rhizomes were studied to evaluate their antidiabetic effects on protein glycation and on the diffusion of glucose in vitro in the present study. Zingiber officinale rhizome aqueous extract were examined at concentrations of 5, 10, 20 and 40 g/L. The antidiabetic effects were found to be dose-dependent. Antidiabetic potential of Zingiber officinale was mainly through inhibition of the glucose diffusion and to a limited extent by reducing the glycation. However, further studies are needed to determine in vitro effects of therapeutic potential by restraining postprandial glucose absorptions and plasma protein glycations in diabetic subjects.Extratos aquosos de rizomas Zingiber officinale foram estudados para avaliar os seus efeitos antidiabéticos em glicação de proteínas e sobre a difusão de glicose in vitro, no presente estudo. Extratos aquosos de Zingiber officinale foram examinados nas concentrações de 5, 10, 20 e 40 g extrato de planta/L. Os efeitos antidiabéticos observados eram dependentes da dose. O potencial antidiabético de Zingiber officinale se verificou, principalmente, através da inibição da difusão de glicose e, em menor extensão, através da redução da glicação. Estudos adicionais são necessários para elucidar se efeitos in vitro representam potencial terapêutico, restringindo a absorção de glicose pós-prandial e a glicação de proteínas plasmáticas em indivíduos diabéticos

Severe developmental delay, epilepsy and neonatal diabetes (DEND) syndrome: a case report

Developmental delay, Epilepsy and Neonatal Diabetes (DEND) syndrome is the most severe form of Permanent Neonatal Diabetes with KCNJ11 gene mutation which accounts for most of the cases. We report the first DEND syndrome in Malaysia with heterozygous missense mutation Q52R at KCNJ11 (Kir6.2) gene with delayed presentation beyond 6 months of age and failure to transition to glibenclamide. This report signifies the phenotypical variability among patients with the same genetic mutation and the different response to treatment