94 research outputs found

    Measuring a Level of Water Pollution in Sungai Pinang Using a Mathematical Model

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    Mathematical models are now a popular tool in many applications such as physics, economics and engineering; and provide useful information for decision making and planning. Water pollution in Malaysia has reached a level that needs attention and intervention from environmental department and government. In order to make a strong case, this paper has done a study on measuring the pollution level of Sungai Pinang which is located in Penang Island, Malaysia. Advection-Dispersion equation is one of the mathematical models that often use in evaluating the level of water pollution in the river. This paper applies this model and compares the result of this study with the studies done in the previous research worldwide to evaluate the severity of the pollution. The authors hope that this paper will create awareness to relevant department and also to community in genera

    Exergy Analysis and Efficiency Improvement of a Coal Fired Thermal Power Plant in Queensland

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    Energy analysis is an important tool to improve energy efficiency of a thermodynamic system. The conventional method of energy analysis is based on the first law of thermodynamics, which focuses on conservation of energy. The limitation of this analysis is that it does not take into account properties of the system environment, or degradation of the energy quality through dissipative processes. Exergy analysis is very effective in this regard, as it deals with the usable energy with reference to environment. It is based on the second law of thermodynamics. The main purpose of exergy analysis is to identify where and how much exergy is destroyed. This destruction of exergy in a process is proportional to the entropy generation in it, which accounts for the inefficiencies due to irreversibility. This research conducts exergy analysis in one unit of a coal-fired power plant in Central Queensland, Australia. The exergy analysis identifies where and how much exergy is destroyed in the system and its components. Based on the analysis, it assesses different options to improve the efficiency of the system. It shows that only a small amount of useful energy can be recovered through a heat recovery system. Substantial improvement to the thermodynamic cycle is possible, but it requires considerable alteration of the power generation system

    YAP and TAZ maintain PROX1 expression in the developing lymphatic and lymphovenous valves in response to VEGF-C signaling

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    Lymphatic vasculature is an integral part of digestive, immune and circulatory systems. The homeobox transcription factor PROX1 is necessary for the development of lymphatic vessels, lymphatic valves (LVs) and lymphovenous valves (LVVs). We and others previously reported a feedback loop between PROX1 and vascular endothelial growth factor-C (VEGF-C) signaling. PROX1 promotes the expression of the VEGF-C receptor VEGFR3 in lymphatic endothelial cells (LECs). In turn, VEGF-C signaling maintains PROX1 expression in LECs. However, the mechanisms of PROX1/VEGF-C feedback loop remain poorly understood. Whether VEGF-C signaling is necessary for LV and LVV development is also unknown. Here, we report for the first time that VEGF-C signaling is necessary for valve morphogenesis. We have also discovered that the transcriptional co-activators YAP and TAZ are required to maintain PROX1 expression in LVs and LVVs in response to VEGF-C signaling. Deletion o

    Degradation and physical properties of sugar palm starch/ sugar palm nanofibrillated cellulose bionanocomposite

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    This paper aims to study the degradation rate of sugar palm nanofibrillated cellulose (SPNFCs) and sugar palm starch (SPS). SPNFCs were isolated from sugar palm fiber, while SPS is extracted from sugar palm trunk. The SPNFCs were reinforced with SPS biopolymer as biodegradable reinforcement materials of different diameter/length based on the number of passes of high pressurize homogenization process (5, 10 and 15 passes represented by SPS/SPNFCs-5, SPS/SPNFCs-10, and SPS/SPNFCs-15). These SPNFCs were incorporated into SPS plasticized with glycerol and sorbitol via solution casting method. Soil burial experiment performed on SPS and SPS/SPNFCs bionanocomposites showed that SPS was degraded more rapidly by losing 85.76% of its mass in 9 days compared to 69.89% by SPS/SPNFCs-15 bionanocomposite. The high compatibility between SPNFCs nanofiber and SPS biopolymer matrices can be observed through field emission scanning electron microscopy (FE-SEM)

    Cerebrospinal fluid markers of neuronal and glial cell damage in patients with autoimmune neurologic syndromes with and without underlying malignancies

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    Autoimmune neurologic syndromes can be paraneoplastic (associated with malignancies and/or onconeural antibodies), or non-paraneoplastic. Their clinical presentation is often similar. As prognosis is related to malignancy treatment, better biomarkers are needed to identify patients with malignancy. We investigated cerebrospinal fluid (CSF) markers of neuronal (neurofilament light chain, NFL and total tau protein, T-tau) and glial (glial fibrillary acidic protein) damage. CSF-NFL and T-tau were increased in both paraneoplastic and non-paraneoplastic autoimmune syndromes. Patients with manifest malignancies were older, had less epilepsy, more focal central and peripheral neurological signs and symptoms, and worse long-term outcome, than those without malignancy. CSF-NFL-levels predicted long-term outcome but were not diagnostic for malignancy, after age adjustment

    One- and two-stage surgical revision of peri-prosthetic joint infection of the hip: a pooled individual participant data analysis of 44 cohort studies.

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    One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip

    Segmentation of Salient Closed Contours from Real Images

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    Using a saliency measure based on the global property of contour closure, we have developed a method that reliably segments out salient contours bounding unknown objects from real edge images. The measure also incorporates the Gestalt principles of proximity and smooth continuity that previous methods have exploited. Unlike previous measures, we incorporate contour closure by finding the eigen-solution associated with a stochastic process that models the distribution of contours passing through edges in the scene. The segmentation algorithm utilizes the saliency measure to identify multiple closed contours by finding strongly-connected components on an induced graph. The determination of strongly-connected components is a direct consequence of the property of closure. We report for the first time, results on large real images for which segmentation takes an average of about 10 secs per object on a general-purpose workstation. The segmentation is made efficient for such large images by exploiting the inherent symmetry in the task
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