Recovery of diesel-like fuel from waste palm oil by pyrolysis using a microwave heated bed of activated carbon

Microwave pyrolysis using a well-mixed bed of activated carbon as both the microwave absorber and reaction bed was investigated for its potential to recover useful products from waste palm cooking oil – a cooking oil widely used in Asia. The carbon bed provided rapid heating (∼18 °C/min) and a localized reaction hot zone that thermally promoted extensive pyrolysis cracking of the waste oil at 450 °C, leading to increased production of a biofuel product in a process taking less than 25 min. It also created a reducing reaction environment that prevented the formation of undesirable oxidized compounds in the biofuel. The pyrolysis produced a biofuel product that is low in oxygen, free of sulphur, carboxylic acid and triglycerides, and which also contains light C$_{10}$-C$_{15}$ hydrocarbons and a high calorific value nearly comparable to diesel fuel, thus showing great potential to be used as fuel. This pyrolysis approach offers an attractive alternative to transesterification that avoids the use of solvents and catalysts, and the need to remove free fatty acids and glycerol from the hydrocarbon product. The pyrolysis apparatus operated with an electrical power input of 1.12 kW was capable of producing a biofuel with an energy content equivalent to about 3 kW, showing a positive energy ratio of 2.7 and ≥73% recovery of the energy input to the system. The results show that the pyrolysis approach has huge potential as a technically and energetically viable means for the recovery of biofuels from the waste oil.The authors acknowledge the financial support by the Ministry of Science, Technology and Innovation and the Ministry of Higher Education Malaysia for the conduct of the research under the E-Science fund (UMT/RMC/SF/13/52072(5), Vot 52072) and the FRGS grant (FRGS/1/2016/TK07/UMT/02/3, Vot 59434).This is the author accepted manuscript. The final version is available from Elsevier via https://doi.org/10.1016/j.energy.2016.09.07

Determination of Trace Elements in Sediments Samples by Using Neutron Activation Analysis

The Juru River is a highly industrialized, urbanized, and agricultural catchment. This study aimed to investigate trace elements in Juru mangrove sediments, including geochemical baselines and enrichment. Sediment was collected from the mangrove in Juru, Penang, Malaysia. A total of eight target elements was examined.  Instrumentation activation analysis (INAA) was used to determine the concentration of Fe, V, Cr, Zn and Co. Atomic absorption spectrometry (AAS) was used to determine the concentration of elements that not detectable by INAA (Cd, Pb, and As). In both methods, validated reference material studies were used for validation of the methodology. Metal pollution was estimated using the Enrichment Factor (EF), Geoaccumulation Index (Igeo), Contamination Factor (CF), and Pollutant Load Index (PLI). The EF, Igeo, and CF ranges from 0.45–7.96, -2.18 – 1.95, and 0.33–5.83 respectively. The order of accumulation of the elemental concentration found was Fe > Zn> Cr > V > Pb > As > Co >Cd. The computed mean value of PLI exceeds the unit (PLI > 1)

Prevalence and awareness of lower urinary tract symptoms among males in the Outpatient Clinics of Universiti Kebangsaan Malaysia Medical Centre.

This study aims to determine the prevalence of lower urinary tract symptoms (LUTS) and level of awareness among male outpatients in Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A questionnaire consisting of demographic data, questions related to knowledge, attitude and practice on BPH and the International Prostate Symptom Score (IPSS) was used for this study. Uroflowmetry and bladder scan were used to evaluate the function of the urinary tract and severity of BPH. Urine dipstick was done for glycosuria, proteinuria and haematuria. A total of 220 respondents were surveyed. The prevalence of moderately and severely symptomatic LUTS was 42.7%. The most commonly reported LUTS were nocturia (78.2%), frequency (58.2%) and incomplete emptying (44.6%). The prevalence of glycosuria, proteinuria and haematuria were 23.6%, 11.4% and 1.8% respectively. There was a significant association between increasing age with the severity of LUTS (p=0.005). Out of 102 respondents with voided urine volume greater than 150 mL, there was a significant decrease in maximum (Qmax) (p=0.039) and average (Qave) urine flow rates with every 10 years increase of age (p=0.001). The majority of respondents (59.5%) have heard of BPH before. Over 78.2% of the respondents would seek medical attention if they have LUTS with 15.9% saying they would seek traditional treatment. In conclusion, the prevalence of LUTS was high and the level of awareness was satisfactory

Predation on Multiple Prey Types Across a Disturbance Gradient in Tropical Montane Forests of Peninsular Malaysia

Predation plays a critical role in animal and plant survivorship, and can be highly sensitive to habitat loss and disturbance. Tropical montane forests in Southeast Asia are being modified rapidly by land-use change, and the consequences of this on predation likelihood are poorly understood. In Peninsular Malaysia, we conducted predation experiments at eight tropical montane forest sites along a disturbance gradient. We investigated whether (1) predation pressure in primary forests differs between different mountains; (2) predation probability is linked to habitat degradation; and (3) vegetation variables explain predation occurrence. At each forest site, we placed artificial nests with real and model quail eggs, dishes with real and artificial seeds of the cempedak (Artocarpus champeden), models resembling four-lined tree frogs (Polypedetes leucomystax) and models of the late instar caterpillar of the common Mormon (Papilio polytes) at points 100 m apart for three nights. Using Bayesian binomial simulations, we showed that predation likelihood in primary forests from different mountains can vary (e.g., probability of the difference in predation rate of artificial caterpillars between two primary forests was estimated at 82–100%). We also found that higher predation was not linked to habitat degradation for all artificial prey and seeds (e.g., comparing forests of varying degrees of disturbance from the same mountain, the probability that predation of an artificial caterpillar is lower at the primary forest was estimated at 2–20% only). Model selection and hierarchical partitioning showed that vegetation variables can explain predation occurrence, suggesting microhabitat characteristics may be influential. Conducting predation experiments by using artificial prey and seeds is useful for comparing predation likelihood at different sites, making ecological comparisons, and for informing conservation decisions. This novel approach of using multiple prey items also showed that predation for each can vary and thus caution against deploying a single prey type to draw broad inferences of predation in degraded systems

Reduction of covalently closed circular DNA with long-term nucleos(t)ide analogue treatment in chronic hepatitis B

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Impacts of Habitat Degradation on Tropical Montane Biodiversity and Ecosystem Services: A Systematic Map for Identifying Future Research Priorities

Tropical montane forests (TMFs) are major centers of evolutionary change and harbor many endemic species with small geographic ranges. In this systematic map, we focus on the impacts of anthropogenic habitat degradation on TMFs globally. We first determine how TMF research is distributed across geographic regions, degradation type (i.e., deforestation, land-use conversion, habitat fragmentation, ecological level (i.e., ecosystem, community, population, genetic) and taxonomic group. Secondly, we summarize the impacts of habitat degradation on biodiversity and ecosystem services, and identify deficiencies in current knowledge. We show that habitat degradation in TMFs impacts biodiversity at all ecological levels and will be compounded by climate change. However, despite montane species being perceived as more extinction-prone due to their restricted geographic ranges, there are some indications of biotic resilience if the impacts to TMFs are less severe. Species richness and key species interactions can be maintained in mildly degraded sites, and gene flow can persist between TMF fragments. As such, minimally degraded areas such as secondary forests and restored areas could play a crucial role in maintaining the meta-community and ecosystem services of TMFs—either via resource provision or by linking patches of pristine forest. Research deficiencies highlighted include poor research representation in Asian and African TMFs, few assessments of population and genetic-level responses to fragmentation, and little assessment of the impacts of habitat fragmentation at all ecological levels. To address these concerns, we present a list of the top research priorities to urgently address the growing threat of habitat degradation in TMF

Impacts of Habitat Degradation on Tropical Montane Biodiversity and Ecosystem Services: A Systematic Map for Identifying Future Research Priorities

Tropical montane forests (TMFs) are major centers of evolutionary change and harbor many endemic species with small geographic ranges. In this systematic map, we focus on the impacts of anthropogenic habitat degradation on TMFs globally. We first determine how TMF research is distributed across geographic regions, degradation type (i.e., deforestation, land-use conversion, habitat fragmentation, ecological level (i.e., ecosystem, community, population, genetic) and taxonomic group. Secondly, we summarize the impacts of habitat degradation on biodiversity and ecosystem services, and identify deficiencies in current knowledge. We show that habitat degradation in TMFs impacts biodiversity at all ecological levels and will be compounded by climate change. However, despite montane species being perceived as more extinction-prone due to their restricted geographic ranges, there are some indications of biotic resilience if the impacts to TMFs are less severe. Species richness and key species interactions can be maintained in mildly degraded sites, and gene flow can persist between TMF fragments. As such, minimally degraded areas such as secondary forests and restored areas could play a crucial role in maintaining the meta-community and ecosystem services of TMFs—either via resource provision or by linking patches of pristine forest. Research deficiencies highlighted include poor research representation in Asian and African TMFs, few assessments of population and genetic-level responses to fragmentation, and little assessment of the impacts of habitat fragmentation at all ecological levels. To address these concerns, we present a list of the top research priorities to urgently address the growing threat of habitat degradation in TMF

Seven-Year Treatment Outcome of Entecavir in a Real-World Cohort: Effects on Clinical Parameters, HBsAg and HBcrAg Levels

published_or_final_versio

Intrusion detection routers: Design, implementation and evaluation using an experimental testbed

In this paper, we present the design, the implementation details, and the evaluation results of an intrusion detection and defense system for distributed denial-of-service (DDoS) attack. The evaluation is conducted using an experimental testbed. The system, known as intrusion detection router (IDR), is deployed on network routers to perform online detection on any DDoS attack event, and then react with defense mechanisms to mitigate the attack. The testbed is built up by a cluster of sufficient number of Linux machines to mimic a portion of the Internet. Using the testbed, we conduct real experiments to evaluate the IDR system and demonstrate that IDR is effective in protecting the network from various DDoS attacks. © 2006 IEEE.published_or_final_versio

Investigation of the Hemodynamic Effect of Stent Wires on Renal Arteries in Patients with Abdominal Aortic Aneurysms Treated with Suprarenal Stent-Grafts

The purpose of the study was to investigate the hemodynamic effect of stent struts (wires) on renal arteries in patients with abdominal aortic aneurysms (AAAs) treated with suprarenal stent-grafts. Two sample patients with AAA undergoing multislice CT angiography pre- and postsuprarenal fixation of stent-grafts were selected for inclusion in the study. Eight juxtarenal models focusing on the renal arteries were generated from the multislice CT datasets. Four types of configurations of stent wires crossing the renal artery ostium were simulated in the segmented aorta models: a single wire crossing centrally, a single wire crossing peripherally, a V-shaped wire crossing centrally, and multiple wires crossing peripherally. The blood flow pattern, flow velocity, wall pressure, and wall shear stress at the renal arteries pre- and post-stent-grafting were analyzed and compared using a two-way fluid structure interaction analysis. The stent wire thickness was simulated with a diameter of 0.4, 1.0, and 2.0 mm, and hemodynamic analysis was performed at different cardiac cycles. The interference of stent wires with renal blood flow was mainly determined by the thickness of stent wires and the type of configuration of stent wires crossing the renal ostium. The flow velocity was reduced by 20–30% in most of the situations when the stent wire thickness increased to 1.0 and 2.0 mm. Of the four types of configuration, the single wire crossing centrally resulted in the highest reduction of flow velocity, ranging from 21% to 28.9% among three different wire thicknesses. Wall shear stress was also dependent on the wire thickness, which decreased significantly when the wire thickness reached 1.0 and 2.0 mm. In conclusion, our preliminary study showed that the hemodynamic effect of suprarenal stent wires in patients with AAA treated with suprarenal stent-grafts was determined by the thickness of suprarenal stent wires. Research findings in our study are useful for follow-up of patients treated with suprarenal stent-grafts to ensure long-term safety of the suprarenal fixation