754 research outputs found

    Hydraulic performance and modelling of pressurized drip irrigation system

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    This study was conducted at Laman Sayur, Malaysia Agro Exposition Park Serdang (MAEPS), to investigate the hydraulic performance of a small-scale drip irrigation system. The modelling was carried out using EPANET software to understand how the drip irrigation system is operated. Model results show that the errors are small, i.e., 2.2% and 3.0% for pressures, and 1.7% for discharge in lateral pipe 1 and lateral pipe 2. The root mean square error (RMSE) and the mean bias error (MBE) for discharge were recorded at 0.04 L/h and 0.03 L/h for lateral pipe 1 and 0.04 L/h and 0.02 L/h for lateral pipe 2. RMSE and MBE for pressure were recorded at 0.61 m and 0.68 m for lateral pipe 1, and 0.79 m and 0.68 m for lateral pipe 2, respectively. These results show that the model yields good performance. For hydraulic performance, the field measurement was conducted with four operating pressures: P1 (15.3), P2 (20.4), P3 (25.5), and P4 (28.6) meters. The hydraulic parameters evaluated were the coefficient of uniformity (CU), the emission uniformity (EU), the coefficient of variation (CV), and the emitter flow variation (EFV). The operating pressure during the measurement is constant according to the specified pressure. The results show that CU, CV, and EU are in the excellent classification, and values of CU and EU have more than 95% efficiency. The value for CV is below 0.03, which is excellent. The EFV is 10% when operating at 25.5 m and 15.3 m and is considered desirable. On the other hand, for the 28.6 m and 15.3 m operating pressures, the EFV parameters were recorded at 13.6% and 10.29%, respectively, and are classified acceptable. This study concluded that the operating pressures, P2 (20.4 m) and P3 (25.5 m), were performed under excellent classification for all hydraulic parameters evaluated. Based on the outputs from the model, it is inferred that the existing drip irrigation system at Laman Sayur MAEPS is operated in an over-powered state. With the current pump power consumption, the irrigation system could be operated at a minimum of four times the capacity of the existing irrigation system. To reduce the power consumption, it is suggested that the system is operated at a lower pumping power. This would minimize the operating costs especially for the development of a new drip irrigation system that has the same capacity as the drip irrigation system that is currently being operated at Laman Sayur, MAEPS Serdang

    Timing of infection and prior immunization with respiratory syncytial virus (RSV) in RSV-enhanced allergic inflammation

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    Respiratory syncytial virus (RSV) infection has been shown to be a risk factor for the development of allergy in humans and mice. The allergy-enhancing properties of RSV may be dependent on atopic background and an individual's history of RSV infection. We examined the influence of the timing of infection and prior inoculation with RSV in a mouse model of allergic asthma. Mice were sensitized to and challenged with ovalbumin (OVA) and were inoculated with RSV either before or during the sensitization or challenge period. One group of mice was inoculated with RSV both before sensitization to OVA and during challenge with OVA. Increased pulmonary expression of interleukin (IL)-4, IL-5, and IL-13 mRNA and aggravated alveolitis and hypertrophy of mucus-producing cells were observed only when OVA-sensitized mice were inoculated with RSV shortly before or during challenge with OVA. Despite protection against viral replication, prior inoculation with RSV did not abrogate RSV-enhanced, OVA-induced expression of T helper 2 (Th2) cytokines in the lung. In conclusion, inoculation with RSV enhances allergic disease only when the immune system has already been Th2-primed by the allergen (i.e., OVA). This RSV-enhanced allergy is not completely abrogated by prior inoculation with RSV

    Multi-Layer Perceptron (MLP)-Based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) Stock Forecasting Model

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    The prediction of stocks in the stock market is important in investment as it would help the investor to time buy and sell transactions to maximize profits. In this paper, a Multi-Layer Perceptron (MLP)-based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) model was used to predict the prices of the Apple Inc. weekly stock prices over a time horizon of 1995 to 2013. The NARX model belongs is a system identification model that constructs a mathematical model from the dynamic input/output readings of the system, and predicts the future behaviour of the system based on the constructed mathematical model. The One Step Ahead (OSA) and correlation tests were used to test validate the model. Results demonstrate the predictive ability of the model while producing Gaussian residuals (indicating the validity of the model)

    A systematic review of naturalistic interventions in refugee populations

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    Naturalistic interventions with refugee populations examine outcomes following mental health interventions in existing refugee service organisations. The current review aimed to examine outcomes of naturalistic interventions and quality of the naturalistic intervention literature in refugee populations with the view to highlight the strengths and limitations of naturalistic intervention studies. Database search was conducted using the search terms ‘refugee’, ‘asylum seeker’, ‘treatment’, ‘therapy’ and ‘intervention. No date limitations were applied, but searches were limited to articles written in English. Seven studies were identified that assessed the outcome of naturalistic interventions on adult refugees or asylum seekers in a country of resettlement using quantitative outcome measures. Results showed significant variation in the outcomes of naturalistic intervention studies, with a trend towards showing decreased symptomatology at post-intervention. However, conclusions are limited by methodological problems of the studies reviewed, particularly poor documentation of intervention methods and lack of control in the design of naturalistic intervention studies. Further examination of outcomes following naturalistic interventions is needed with studies which focus on increasing the rigour of the outcome assessment process

    Estimating the conservation value of Giant Panda Conservation Centre in Zoo Negara, Malaysia using contingent valuation method

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    The Giant Panda Conservation Centre (GPCC), which is the latest edition to Zoo Negara Malaysia, exhibits as an outreach conservational programme. To understand the conservation value of the Giant Panda Programme in Zoo Negara, a study using Contingent Valuation Method (CVM) approach is conducted. The main objective of the study is to estimate the willingness to pay (WTP) of visitor for the Giant Panda programme at Zoo Negara. Data was collected using a structured questionnaire through face-to-face interview sessions at the GPCC. Findings show that the factors influencing WTP are income, repeat visits of visitors and satisfaction index. Mean WTP is estimated at RM20.28, while the conservation value is estimated at RM5,039,235.24 for the year 2014. This study provides valuable information regarding the conservation value of Giant Panda programme in Malaysia

    Phage Lambda CIII: A Protease Inhibitor Regulating the Lysis-Lysogeny Decision

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    The ATP-dependent protease FtsH (HflB) complexed with HflKC participates in post-translational control of the lysis-lysogeny decision of bacteriophage lambda by rapid degradation of lambda CII. Both phage-encoded proteins, the CII transcription activator and the CIII polypeptide, are required for efficient lysogenic response. The conserved CIII is both an inhibitor and substrate of FtsH. Here we show that the protease inhibitor CIII is present as oligomeric amphipathic α helical structures and functions as a competitive inhibitor of FtsH by preventing binding of the CII substrate. We identified single alanine substitutions in CIII that abolish its activity. We characterize a dominant negative effect of a CIII mutant. Thus, we suggest that CIII oligomrization is required for its function. Real-time analysis of CII activity demonstrates that the effect of CIII is not seen in the absence of either FtsH or HflKC. When CIII is provided ectopically, CII activity increases linearly as a function of the multiplicity of infection, suggesting that CIII enhances CII stability and the lysogenic response. FtsH function is essential for cellular viability as it regulates the balance in the synthesis of phospholipids and lipopolysaccharides. Genetic experiments confirmed that the CIII bacteriostatic effects are due to inhibition of FtsH. Thus, the early presence of CIII following infection stimulates the lysogenic response, while its degradation at later times ensures the reactivation of FtsH allowing the growth of the established lysogenic cell

    A Review Paper On Vision Based Identification, Detection And Tracking Of Weld Seams Path In Welding Robot Environment

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    Welding is an important technology especially for joining between two metals, fabricated and repairing metals products in manufacturing industries such as in automotive industries. To increase the productivity and lower cost, today the welding operation in industries introduces the welding robot. The main challenges to using welding robot is time taken to program robot path for a new job in low to medium volume manufacturing industries. This paper begins with the review of identified, detected and tracked the weld seams path with different type of welding in welding environment. Next, a review of analysis an identified and detect the weld seams path approaches is included with advantages, drawback and limitation. This paper is concluded by a comprehensive summary which discussed the disadvantages and limitation of a robust approach in each stage. The improvement of a new approach in each stage depends on the lack, limitation and the results which are expected from the work

    Comparative economic evaluation of data from the ACRIN national CT colonography trial with three cancer intervention and surveillance modeling network microsimulations

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    Purpose: To estimate the cost-effectiveness of computed tomographic (CT) colonography for colorectal cancer (CRC) screening in average-risk asymptomatic subjects in the United States aged 50 years. Materials and Methods: Enrollees in the American College of Radiology Imaging Network National CT Colonography Trial provided informed consent, and approval was obtained from the institutional review board at each site. CT colonography performance estimates from the trial were incorporated into three Cancer Intervention and Surveillance Modeling Network CRC microsimulations. Simulated survival and lifetime costs for screening 50-year-old subjects in the United States with CT colonography every 5 or 10 years were compared with those for guideline-concordant screening with colonoscopy, flexible sigmoidoscopy plus either sensitive unrehydrated fecal occult blood testing (FOBT) or fecal immunochemical testing (FIT), and no screening. Perfect and reduced screening adherence scenarios were considered. Incremental cost-effectiveness and net health benefits were estimated from the U.S. health care sector perspective, assuming a 3% discount rate. Results: CT colonography at 5- and 10-year screening intervals was more costly and less effective than FOBT plus flexible sigmoidoscopy in all three models in both 100% and 50% adherence scenarios. Colonoscopy also was more costly and less effective than FOBT plus flexible sigmoidoscopy, except in the CRC-SPIN model assuming 100% adherence (incremental cost-effectiveness ratio: 26300perlifeyeargained).CTcolonographyat5and10yearscreeningintervalsandcolonoscopywerenetbeneficialcomparedwithnoscreeninginallmodelscenarios.The5yearscreeningintervalwasnetbeneficialoverthe10yearintervalexceptintheMISCANmodelwhenassuming10026 300 per life-year gained). CT colonography at 5- and 10-year screening intervals and colonoscopy were net beneficial compared with no screening in all model scenarios. The 5-year screening interval was net beneficial over the 10-year interval except in the MISCAN model when assuming 100% adherence and willingness to pay 50 000 per life-year gained. Conclusion: All three models predict CT colonography to be more costly and less effective than non-CT colonographic screening but net beneficial compared with no screening given model assumptions
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