16 research outputs found

    Fault Tree Analysis for Reliability Analysis of Wind Turbines Considering the Imperfect Repair Effect

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    Wind turbines are complex and expensive equipment, requiring high reliability and low maintenance costs. However, most of the existing fault tree analysis (FTA) methods for reliability analysis of wind turbines assume that the repair of wind turbines can restore them to as good as new condition, which is called perfect repair. This assumption may not be realistic in practice, as the repair may not fully recover the original performance or functionality of the equipment or may introduce new defects or errors. This phenomenon is called imperfect repair, which can reduce the reliability of wind turbines over time. To consider the imperfect repair effect in reliability analysis, we present a new FTA approach in this study. In order to predict and assess the failure intensity and dependability of wind turbines under imperfect repair, the proposed FTA technique uses a log-linear proportional intensity model (LPIM). Failure probability, failure rate, and mean time to failure can all be improved with the suggested FTA technique for wind turbines operating with poor repair. The proposed FTA method can also identify the critical components or failure modes most affected by the imperfect repair effect and suggest preventive maintenance actions to improve the reliability of wind turbines. We demonstrate the applicability and effectiveness of the proposed FTA method through a case study on a real or hypothetical wind turbine system under imperfect repair. The findings indicate that the proposed FTA method offers a more precise and authentic assessment of the reliability of wind turbines in the presence of imperfect repair, in contrast to existing FTA methods that assume perfect repair. The findings also demonstrate that the electrical system, hydraulic system, gearbox, generator, and blade are the most critical components or failure modes affecting the system's reliability

    Acute Appendicitis: Relationship of Total Leucocyte Count with Per-Operative Stage

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    Objective: To correlate total leucocyte count(TLC) with per-operative stage of acute appendicitis. Patients and Methods: This cross sectional study was conducted in department of surgery, Pakistan Institute of Medical Sciences (PIMS) from June 2016 to June 2017. A total 77 patients were included through consecutive sampling technique. Statistical Package for Social Sciences (SPSS) version 20 was used to analyze data. Results: A total of 77 patients were included in the study, among them 47 (61%) were males, and 30(39%) were females. Mean age was 22.25 ± 5.19 years. Mean TLC was 12,900 ± 4087 cells/µL Patients having acute appendicitis were labeled as, acute appendicitis stage I which included 59 (76.6%) patients, Gangrenous appendicitis was named as stage II which included 11 (14.3%) patients. Perforated appendicitis was labeled as Stage III in which 7 (9.1%) patients were inducted. In stage I, mean age was 21.89 ± 5.50 years and mean TLC was 12,344 ± 4162 cells/µl. In stage II, mean age was 22.36 ± 3.90 years and mean of total leukocyte count was 15,072 ± 3497 cells/µl. In stage III, mean age was 25.57 ± 3.50 years and mean leukocyte count was 14,214 ± 4141cells/µl (p-value >0.05). Conclusion: Significant statistical association was not found in patients in different stages of appendicitis with respect to TLC (p value >0.05), although patients in all stages had raised mean TLC with mean TLC highest in patients having stage II (Gangrenous appendicitis)

    A Review on MPC Based Self Recovering Intelligent Advance Meter for Smart Grid: Scheme and Challenges

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    The Model Predict Control (MPC) based Intelligent Advance Metering (IAM) is a core maneuver of future smart grids (SG). SG is the advanced generation of electric power and utility system that improve operation technology (OT) and information technology (IT) to provide nonstop, self-recovery, self-configuration, low-cost, and security-based electricity to the consumer in real-time. Smart metering (SM) allows SG to connect the electric, gas, and oil utilities through sensors. Power plants, consumers, and utility companies will be received real-time wireless control IAM with fifth generation (5G) network technology. The aim of 5G network technology is to enable power grid digitalization (PGD) and facilitate the (IOT) Internet of Things for the future advance SG with benefits such as high-rate public safety, low latency, ultra-high speed, large number of connectivity, and reliability. In this paper, we analyze future predictions about energy needs by using MPC, fast self-recovery system, self-configuration, and upgradation, better performance of service provider, faster power connecting after an outage, control electric theft, minimize electric leakage, a large number of wireless connecting of IAM home-based, and real-time monitoring via human machine interface (HMI) and for customer end IAM operation over 5G networks to reduce billing price, reduce meter cost, lower outage cost, and as well as personalized control over electricity consumption and future challenge in this area

    Digital Twin Concept, Method and Technical Framework for Smart Meters

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    Smart meters connect smart grid electricity suppliers and users. Smart meters have become a research hotspot as smart grid applications like demand response, power theft prevention, power quality monitoring, peak valley time of use prices, and peer-to-peer (P2P) energy trading have grown. But, as the carriers of these functions, smart meters have technical problems such as limited computing resources, difficulty in upgrading, and high costs, which to some extent restrict the further development of smart grid applications. To address these issues, this study offers a container-based digital twin (CDT) approach for smart meters, which not only increases the user-facing computing resources of smart meters but also simplifies and lowers the overall cost and technical complexity of meter changes. In order to further validate the effectiveness of this method in real-time applications on the smart grid user side, this article tested and analyzed the communication performance of the digital twin system in three areas: remote application services, peer-to-peer transactions, and real-time user request services. The experimental results show that the CDT method proposed in this paper meets the basic requirements of smart grid user-side applications for real-time communication. The container is deployed in the cloud, and the average time required to complete 100 P2P communications using our smart meter structure is less than 2.4 seconds, while the average time required for existing smart meter structures to complete the same number of P2P communications is 208 seconds. Finally, applications, the future development direction of the digital twin method, and technology architecture are projected

    Determination and Extraction of Acetamiprid Residues in Fruits and Vegetables

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    <p align="center"><span style="font-family: Times New Roman;">  <span style="font-size: medium;">Vegetables (chilies, tomato, cauliflower and cucumber) and fruits (mango and apple) samples were spiked with known quantity (0.50 mg kg-1) of acetamiprid reference standard for testing the retrieval percentage of acetamiprid residue in those vegetables and fruits. The efficiency of different extracting (ethyl acetate and dichloromethane + acetone 8:2) and eluting (ethyl acetate and dichloromethane + acetone 8:2) solvents and adsorbents (activated charcoal and florisil) for clean up purpose was calculated using HPLC. Amongst the extracting solvents ethyl-acetate was observed an effective extracting solvent alone which produced maximum 90-96%  </span><span style="font-size: medium;">recovery for acetamiprid residues while among the eluting solvents a combination of dichloromethane and acetone ( ratio 8:2) produced superior recoveries i.e. 87-95%. Similarly, between the adsorbents used for clean up purpose activated charcoal and florisil in tandem (first from charcoal and then through florisil) yielded recoveries 82-90 % whereas adsorbents used alone in form of activated florisil and charcoal recovered only 70 to 78 % and 71 to 73% acetamiprid residues, respectively in all vegetables and fruits.</span></span></p

    Determination and Extraction of Acetamiprid Residues in Fruits and Vegetables

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      Vegetables (chilies, tomato, cauliflower and cucumber) and fruits (mango and apple) samples were spiked with known quantity (0.50 mg kg-1) of acetamiprid reference standard for testing the retrieval percentage of acetamiprid residue in those vegetables and fruits. The efficiency of different extracting (ethyl acetate and dichloromethane + acetone 8:2) and eluting (ethyl acetate and dichloromethane + acetone 8:2) solvents and adsorbents (activated charcoal and florisil) for clean up purpose was calculated using HPLC. Amongst the extracting solvents ethyl-acetate was observed an effective extracting solvent alone which produced maximum 90-96%  recovery for acetamiprid residues while among the eluting solvents a combination of dichloromethane and acetone ( ratio 8:2) produced superior recoveries i.e. 87-95%. Similarly, between the adsorbents used for clean up purpose activated charcoal and florisil in tandem (first from charcoal and then through florisil) yielded recoveries 82-90 % whereas adsorbents used alone in form of activated florisil and charcoal recovered only 70 to 78 % and 71 to 73% acetamiprid residues, respectively in all vegetables and fruits

    Women’s Political Empowerment through Local Government in the Patriarchal Society of Pakistan

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    The democratic local government empowers community members to decide their destiny. However, it bears different meanings for different people in different socio-cultural settings. This study assesses the intended outcome of the local government system, revived by General Pervez Musharraf’s regime in Pakistan since 2001 regarding women’s political empowerment. In the Devolution Plan 2001, the gender quotas of 33% have been reserved for women in all the three tiers of local government at the district level. However, the existing informal institutional forces like socio-cultural and religious practices did not let women to fully participate and achieve the desired political status. Local women’s representatives have not been able to participate meaningfully in the policymaking at the local level. Therefore, this study suggests revising the design of the local government with a focus on eligibility criteria for the candidates. Moreover, to ensure the political empowerment of women, policymakers should focus on other alternatives like women education, political awareness, and monitoring by the civil society and media

    Growth, chlorophyll content and productivity responses of maize to magnesium sulphate application in calcareous soil

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    Magnesium (Mg) is an essential plant macronutrient responsible for modulating many physiological or biochemical processes such as photosynthetic activity, amino acid synthesis and nucleotide metabolism. Agricultural soils with a more-than-adequate availability of calcium (Ca) have inherent Mg deficiency, potentially resulting in overall reduced soil productivity and crop yield potential. We conducted a field experiment to investigate the optimum soil application of Mg to increase crop growth and productivity under calcareous soil conditions. In addition to recommended soil application of mineral fertilizers, we applied the following four levels of Mg to the soil in the form of anhydrous MgSO4: control, 4 kg Mg ha−1 (Mg4), 8 kg Mg ha−1 (Mg8) and 16 kg Mg ha−1 (Mg16). Results showed that Mg16 application enhanced the plant height (21%), number of grains (18%), 1,000 grains weight (20%), grain yield (20%) and biological yield (9%) over control (p ≤ 0.05). Chlorophyll a, chlorophyll b and total chlorophyll were generally higher at the Mg8 and Mg16 levels than at the control level. Contrasting to increases in growth traits, the concentration of K significantly decreased in grains, leaves and shoots of maize along the soil’s Mg gradient (p ≤ 0.05). We suggest that Mg16 overcomes the deficiency of soil Mg and can increase the crop yield traits in calcareous soils. More investigations of the effect of soil Mg on various crops grown in calcareous soils may add to our knowledge related to the stressing impact of soil Mg on plant K concentration

    Climate change impact uncertainty assessment and adaptations for sustainable maize production using multi-crop and climate models

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    Future climate scenarios are predicting considerable threats to sustainable maize production in arid and semi-arid regions. These adverse impacts can be minimized by adopting modern agricultural tools to assess and develop successful adaptation practices. A multi-model approach (climate and crop) was used to assess the impacts and uncertainties of climate change on maize crop. An extensive field study was conducted to explore the temporal thermal variations on maize hybrids grown at farmer’s fields for ten sowing dates during two consecutive growing years. Data about phenology, morphology, biomass development, and yield were recorded by adopting standard procedures and protocols. The CSM-CERES, APSIM, and CSM-IXIM-Maize models were calibrated and evaluated. Five GCMs among 29 were selected based on classification into different groups and uncertainty to predict climatic changes in the future. The results predicted that there would be a rise in temperature (1.57–3.29 °C) during the maize growing season in five General Circulation Models (GCMs) by using RCP 8.5 scenarios for the mid-century (2040–2069) as compared with the baseline (1980–2015). The CERES-Maize and APSIM-Maize model showed lower root mean square error values (2.78 and 5.41), higher d-index (0.85 and 0.87) along reliable R² (0.89 and 0.89), respectively for days to anthesis and maturity, while the CSM-IXIM-Maize model performed well for growth parameters (leaf area index, total dry matter) and yield with reasonably good statistical indices. The CSM-IXIM-Maize model performed well for all hybrids during both years whereas climate models, NorESM1-M and IPSL-CM5A-MR, showed less uncertain results for climate change impacts. Maize models along GCMs predicted a reduction in yield (8–55%) than baseline. Maize crop may face a high yield decline that could be overcome by modifying the sowing dates and fertilizer (fertigation) and heat and drought-tolerant hybrids

    Effects of Farmyard Manure and Different Phosphorus Inorganic Fertilizer Application Rates on Wheat Cultivation in Phosphorus-Deficient Soil

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    Less phosphorus (P) availability in calcareous alkaline soils is one of the major problems in achieving an optimum crop yield. Its deficiency in plants adversely affects growth and yield attributes. To overcome this issue, growers incorporate inorganic P fertilizers. However, the need for time in the sustainable management of soil fertility in terms of P. Farmyard manure (FYM) application is one of the most popular organic amendments in this regard. Thus, the current study was conducted to explore the best application rate of FYM in combination with inorganic P fertilizer single super phosphate (SSP). There were six treatments i.e., control (0F), 100%SSP (100P), 25% FYM and 75% SSP (25F+75P), 50% FYM and 50% SSP (50F+50P), 75% FYM and 25% SSP (75F+25P), and 100% FYM (100F+0P), applied in three replications. The design of the experiment was a randomized complete block design. For assessment of treatment response, two wheat cultivars (V1 = Pirsabak and V2 = Atta Habib) were used. Results showed that the application of 50F+50P significantly improved the plant height (20.69 and 32.01%), spike/m2 (35.19 and 30.10%), grain (41.10 and 38.16%), and leaf P (49.82 and 71.32%) compared to control in V1 and V2, respectively. A significant improvement in the grain and the biological yield of wheat V2 also validated the efficacious functioning of 50F+50P over control. In conclusion, 50F+50P has the potential to enhance wheat growth and nutrient concentration over control. More investigations are required for a more precise and balanced synchronization of FYM and SSP for the achievement of maximum wheat yield
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