36 research outputs found

    A Hybrid Active Neutral Point Clamped Inverter Utilizing Si and Ga2O3 Semiconductors: Modelling and Performance Analysis.

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    In this paper, the performance of an active neutral point clamped (ANPC) inverter is evaluated, which is developed utilizing both silicon (Si) and gallium trioxide (Ga2O3) devices. The hybridization of semiconductor devices is performed since the production volume and fabrication of ultra-wide bandgap (UWBG) semiconductors are still in the early-stage, and they are highly expensive. In the proposed ANPC topology, the Si devices are operated at a low switching frequency, while the Ga2O3 switches are operated at a higher switching frequency. The proposed ANPC mitigates the fault current in the switching devices which are prevalent in conventional ANPCs. The proposed ANPC is developed by applying a specified modulation technique and an intelligent switching arrangement, which has further improved its performance by optimizing the loss distribution among the Si/Ga2O3 devices and thus effectively increases the overall efficiency of the inverter. It profoundly reduces the common mode current stress on the switches and thus generates a lower common-mode voltage on the output. It can also operate at a broad range of power factors. The paper extensively analyzed the switching performance of UWBG semiconductor (Ga2O3) devices using double pulse testing (DPT) and proper simulation results. The proposed inverter reduced the fault current to 52 A and achieved a maximum efficiency of 99.1%

    An integrated organic farming system: innovations for farm diversification, sustainability, and livelihood improvement of hill farmers

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    IntroductionOrganic farming is a promising solution for mitigating environmental burdens related to input-intensive agricultural practices. The major challenge in organic agriculture is the non-availability of large quantities of organic inputs required for crop nutrition and sustaining soil health, which can be resolved by efficient recycling of the available on- and off-farm resources and the integration of the components as per the specific locations.MethodsAn integrated organic farming system (IOFS) model comprising agricultural and horticultural crops, rainwater harvesting units, livestock components, and provisions for nutrient recycling was developed and disseminated in the adopted organic villages Mynsain, Pynthor, and Umden Umbathiang in the Ri-Bhoi District, Meghalaya, India, to improve the income and livelihood of farmers. Harvested rainwater in farm ponds and Jalkunds was used for live-saving irrigation in the winter months and diversified homestead farming activities, such as growing high-value crops and rearing cattle, pigs, and poultry.ResultsMaize, french bean, potato, ginger, tomato, carrot, and chili yields in the IOFS model increased by 20%−30%, 40%−45%, 25%−30%, 33%−40%, 45%−50%, 37%−50%, and 27%−30%, respectively, compared with traditional practices. Some farmers produced vermicompost in vermibeds (made of high-density polyethylene) and cement brick chambers, generating 0.4−1.25 tons per annum. Two individual farmers, Mr. Jrill Makroh and Mrs. Skola Kurbah obtained net returns (without premium price) of Rs. 46,695 ± 418 and Rs. 31,102 ± 501 from their respective 0.27- and 0.21-ha IOFS models, which is equivalent to Rs. 172,944 ± 1,548/ha/year and Rs. 148,105 ± 2,385/ha/year, respectively. The net returns obtained from the IOFS models were significantly higher than those obtained from the farmers' practice of maize-fallow or cultivation of maize followed by vegetable (~30% of the areas). It is expected that, with the certification of organic products, the income and livelihood of the farmers will improve further over the years. While Mr. Jrill Makroh's model supplied 95.1%, 82.0%, and 96.0% of the total N, P2O5, and K2O, respectively, needed by the system, Mrs. Skola Kurbah's model supplied 76.0%, 68.6%, and 85.5% of the total N, P2O5, and K2O, respectively.DiscussionThus, IOFS models should be promoted among hill farmers so that they can efficiently recycle farm resources and increase their productivity, net returns, and livelihood while reducing their dependence on external farm inputs

    Integrating conservation agriculture with intensive crop diversification in the maize-based organic system: Impact on sustaining food and nutritional security

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    IntroductionDeveloping an intensive sustainable model and feeding a rising population are worldwide challenges. The task is much more daunting in the North Eastern Himalayas, where, low productive maize (Zea mays)- fallow is the main production system in the upland. To increase farm productivity, nutritional security, and energy dietary returns while maintaining environmental sustainability and economic viability, short-duration crops must be included in the maize–fallow system.MethodsA field study was conducted in sandy clay loam soil with a randomized complete block design with three replications for three continuous years (2018–2021) under organic management with two crop management practices, viz., (i) conservation agriculture and (ii) conventional agriculture, and six crop diversification options, viz., (i) maize–sweet corn (Zea mays saccharata)–vegetable pea (Pisum sativa) (M-SC-VP), (ii) maize–sweet corn-mustard (Brassica juncea) (M-SC-M), (iii) maize–sweet corn–lentil (Lens culinaris) (M-SC-L), (iv) maize–sweet corn–vegetable broad bean (Vicia faba) (M-SC-VB), (v) maize (local)–vegetable pea (M-VP), and (vi) maize (local)–fallow (M-F).ResultsThe results showed that, the average system productivity was 5.3% lower for conventional agriculture than conservation agriculture. System carbohydrate, protein, fat, dietary fiber, and dietary energy were ~6.9, 6.8, 7.8, 6.7, and 7%, higher in conservation agriculture than in conventional agriculture, respectively. Similarly, system macronutrients (Ca, Mg, P, and K) and system micronutrients yield (Fe, Mn, Zn, and Cu) were, 5.2–8% and 6.9–7.4% higher in conservation agriculture than in conventional agriculture, respectively. On average, over the years, crop diversification with M-SC-VP/M-SC-VB intensive crop rotation had higher system productivity (158%), production efficiency (157%), net returns (benefit–cost ratio) (44%), and dietary net energy returns (16.6%) than the local maize–vegetable pea system. Similarly, the M-SC-VP/M-SC-VB system improved the nutritional security by improving Ca, Mg, P, K, Fe, Mn, Zn, and Cu yield by 35.5–135.7% than the local M-VP system.DiscussionConservation agriculture with M-SC-VP/M-SC-VB rotation showed significantly (p &amp;lt; 0.05) higher productivity, carbohydrate yield, protein yield, fat yield, and dietary fiber production. It is concluded that conservation agriculture improved soil health and performed better than conventional agriculture in maize-based intensive cropping systems. Overall results indicate that crop diversification with M-SC-VP/M-SC-VB can potentially increase calorie and protein consumption and farm profitability.</jats:sec

    Effect of land-use change along altitudinal gradients on soil micronutrients in the mountain ecosystem of Indian (Eastern) Himalaya

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    AbstractManagement of soil micronutrients for better crop production needs a sound understanding of their status and causes of variability. This is more relevant for acid soils of the mountain ecosystem of Eastern Himalaya (Northeast India). We assessed the status, and the effect of land uses along altitudinal gradients (14 to 4090 masl) on soil properties and micronutrient concentrations (DTPA extractable Fe, Mn, Cu, and Zn) across the region. Soils varied widely in micronutrient concentrations: Fe from 0.665 to 257.1 mg kg−1 while Mn, Cu, and Zn from traces to 93.4, 17.1, and 34.2 mg kg−1, respectively. On conversion of evergreen forests (EF) to upland agriculture (Shifting—SC and Settled—SA) and plantation (PH), Mn, Cu, and Zn concentrations decreased significantly from 30.5, 1.74, and 2.13 mg kg−1 to 6.44–17.8, 0.68–0.81, and 1.06–1.42 mg kg−1, respectively. Grassland (GL) and lowland paddy (LP) had comparable Fe, Mn, and Cu concentrations (except Zn). Degradation of EF to scrubland (SL) recorded the lowest Mn (5.91 mg kg−1), Cu (0.59 mg kg−1), and Zn (0.68 mg kg−1) concentrations. Fe concentration was however increased in degraded SL (+ 73%) over EF (48.7 mg kg−1). The distribution of micronutrients among the land uses was inconsistent and followed the order: (i) Fe: SL &gt; PH &gt; LP &gt; EF &gt; GL &gt; SC &gt; SA, (ii) Mn: EF &gt; GL &gt; LP &gt; PH &gt; SC &gt; SA &gt; SL; (iii) Cu: EF &gt; GL &gt; LP &gt; SC &gt; SA = PH &gt; SL; and (iv) Zn: GL &gt; EF &gt; LP &gt; SC &gt; SA &gt; PH &gt; SL. Four micronutrients responded differently and followed a non-linear, 6th—order polynomial trend along the altitudinal gradients (&lt; 500 to 4100 masl). Peak concentrations of Fe, Mn, and Cu were recorded at 1001–2000 m while Zn was recorded at &gt; 4000 masl. The variability (54–64%) in soil micronutrients was mainly controlled by three key soil properties: acidity, clay, and organic carbon contents. Thus, altitude-specific land-use management holds significance in the distribution of available soil micronutrients in hilly ecosystems.</jats:p

    Data_Sheet_1_Integrating conservation agriculture with intensive crop diversification in the maize-based organic system: Impact on sustaining food and nutritional security.docx

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    IntroductionDeveloping an intensive sustainable model and feeding a rising population are worldwide challenges. The task is much more daunting in the North Eastern Himalayas, where, low productive maize (Zea mays)- fallow is the main production system in the upland. To increase farm productivity, nutritional security, and energy dietary returns while maintaining environmental sustainability and economic viability, short-duration crops must be included in the maize–fallow system.MethodsA field study was conducted in sandy clay loam soil with a randomized complete block design with three replications for three continuous years (2018–2021) under organic management with two crop management practices, viz., (i) conservation agriculture and (ii) conventional agriculture, and six crop diversification options, viz., (i) maize–sweet corn (Zea mays saccharata)–vegetable pea (Pisum sativa) (M-SC-VP), (ii) maize–sweet corn-mustard (Brassica juncea) (M-SC-M), (iii) maize–sweet corn–lentil (Lens culinaris) (M-SC-L), (iv) maize–sweet corn–vegetable broad bean (Vicia faba) (M-SC-VB), (v) maize (local)–vegetable pea (M-VP), and (vi) maize (local)–fallow (M-F).ResultsThe results showed that, the average system productivity was 5.3% lower for conventional agriculture than conservation agriculture. System carbohydrate, protein, fat, dietary fiber, and dietary energy were ~6.9, 6.8, 7.8, 6.7, and 7%, higher in conservation agriculture than in conventional agriculture, respectively. Similarly, system macronutrients (Ca, Mg, P, and K) and system micronutrients yield (Fe, Mn, Zn, and Cu) were, 5.2–8% and 6.9–7.4% higher in conservation agriculture than in conventional agriculture, respectively. On average, over the years, crop diversification with M-SC-VP/M-SC-VB intensive crop rotation had higher system productivity (158%), production efficiency (157%), net returns (benefit–cost ratio) (44%), and dietary net energy returns (16.6%) than the local maize–vegetable pea system. Similarly, the M-SC-VP/M-SC-VB system improved the nutritional security by improving Ca, Mg, P, K, Fe, Mn, Zn, and Cu yield by 35.5–135.7% than the local M-VP system.DiscussionConservation agriculture with M-SC-VP/M-SC-VB rotation showed significantly (p < 0.05) higher productivity, carbohydrate yield, protein yield, fat yield, and dietary fiber production. It is concluded that conservation agriculture improved soil health and performed better than conventional agriculture in maize-based intensive cropping systems. Overall results indicate that crop diversification with M-SC-VP/M-SC-VB can potentially increase calorie and protein consumption and farm profitability.</p

    Optimized Energy Management Schemes for Electric Vehicle Applications: A Bibliometric Analysis towards Future Trends

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    Concerns over growing greenhouse gas (GHG) emissions and fuel prices have prompted researchers to look into alternative energy sources, notably in the transportation sector, accounting for more than 70% of carbon emissions. An increasing amount of research on electric vehicles (EVs) and their energy management schemes (EMSs) has been undertaken extensively in recent years to address these concerns. This article aims to offer a bibliometric analysis and investigation of optimized EMSs for EV applications. Hundreds (100) of the most relevant and highly influential manuscripts on EMSs for EV applications are explored and examined utilizing the Scopus database under predetermined parameters to identify the most impacting articles in this specific field of research. This bibliometric analysis provides a survey on EMSs related to EV applications focusing on the different battery storages, models, algorithms, frameworks, optimizations, converters, controllers, and power transmission systems. According to the findings, more articles were published in 2020, with a total of 22, as compared to other years. The authors with the highest number of manuscripts come from four nations, including China, the United States, France, and the United Kingdom, and five research institutions, with these nations and institutions accounting for the publication of 72 papers. According to the comprehensive review, the current technologies are more or less capable of performing effectively; nevertheless, dependability and intelligent systems are still lacking. Therefore, this study highlights the existing difficulties and challenges related to EMSs for EV applications and some brief ideas, discussions, and potential suggestions for future research. This bibliometric research could be helpful to EV engineers and to automobile industries in terms of the development of cost-effective, longer-lasting, hydrogen-compatible electrical interfaces and well-performing EMSs for sustainable EV operations
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