Padam Prasad Paudel

ScienceDirect — This study comprehensively investigates microwave-assisted pyrolysis of agroforestry waste into quality biochar through systematic evaluation of process variables, operating modes, and quantification techniques to address key challenges for production optimization. Building on this, 92 systematic experiments were conducted across various agroforestry residues, evaluating more than ten control parameters classified by their impact on yield and quality: primary (power, time, temperature, heating-rate, feedstock), secondary (moisture content, particle size, sweep-gas flow, susceptor use), and tertiary (reactor configuration, control modes). Four operating modes were investigated: constant power with/without high‐temperature alarm, fixed temperature, and controlled heating‐rate; and two novel metrics (carbonized amount and absolute yield) were studied alongside traditional metrics to more accurately quantify biochar production and quality. Microwave power and residence time emerged as the primary drivers of yield and carbonization, while heating rate and target temperature acted as fundamental dependent factors. Constant‐power operation without alarm achieved the highest reproducibility and absolute yield (up to 33.85 %), whereas controlled ramping produced biochars with HHV > 30 MJ/kg and fixed carbon > 70 %. Under optimal conditions of 500 W, 20–40 min residence time, 400–500 °C, 10–15 % moisture content, and < 3.15 mm particle size, energy efficiency reached up to 54.1 % while maintaining superior biochar quality. This comprehensive framework enables tunable, scalable microwave‐pyrolysis protocols for sustainable biochar production from biomass wastes.

ScienceDirect — Microwave assisted pyrolysis offers a rapid, energy efficient route to convert agroforestry residues into high value biochar but is hindered by hotspots, temperature non-uniformity, imprecise measurements, partial carbonization, and poor replicability. This study combines constant-power operation with new metrics to overcome these challenges and accurately quantify biochar production. A central-composite response-surface design (30 runs at 300–700 W and 20–60 min) was applied to oak sawdust, perilla stem and rice straw to model seven responses, including two novel metrics (carbonized amount and absolute yield), as well as energy-specific yield, higher heating value, energy efficiency, energy yield and process temperature. Quadratic regressions demonstrated excellent fits (R2 up to 0.96; adequate precision >20) and confirmed that both power and time exert highly significant effects (p < 0.001) on all responses. Carbonized amount and HHV increased with power and time until optimal thresholds, while absolute yield peaked at 500 W/40 min. Energy efficiency was maximized at moderate condition (500 W/20 min)– 70.8 %, 54.1 % and 58.4 % for oak, perilla and rice straw, respectively. Multi-response optimization identified global optimum at 616 W/26 min for oak (Derringer’s desirability of 0.547), with feedstock-specific conditions at 590 W/20 min for rice straw and 594 W/29 min for perilla. Oak sawdust offered the widest operational window and highest energy metrics; rice straw achieved near-complete carbonization at minimal energy; perilla delivered intermediate performance with rapid carbonization. This tunable framework enables energy-efficient biochar production for energy recovery and fuel applications.

arxiv.org — Ginkgo biloba trees are widely planted in urban areas of developed countries for their resilience, longevity and aesthetic appeal. Annual pruning to control tree size, shape and interference with traffic and pedestrians generates large volumes of unutilized Ginkgo biomass. This study aimed to valorize these pruning residues into charcoal by optimizing pyrolysis conditions and evaluating its fuel properties.

Wiley Online Library — Ginkgo biloba trees are widely planted in urban areas of developed countries for their resilience, longevity and aesthetic appeal. Annual pruning to control tree size, shape and interference with traffic and pedestrians generates large volumes of unutilized Ginkgo biomass. This study aimed to valorize these pruning residues into charcoal by optimizing pyrolysis conditions and evaluating its fuel properties. The pyrolysis experiment was conducted at 400–600°C, after oven drying pretreatment. The mass yield of charcoal was found to vary from 27.33 to 32.05% and the approximate volume shrinkage was found to be 41.19–49.97%. The fuel properties of the charcoals were evaluated using the moisture absorption test, proximate and ultimate analysis, thermogravimetry, calorimetry and inductively coupled plasma optical emission spectrometry. The calorific value improved from 20.76 to 34.26 MJ kg−1 with energy yield up to 46.75%. Charcoal exhibited superior thermal stability and better combustion performance. The results revealed satisfactory properties compared with other biomass, coal and biochar standards. The product complied with first-grade standards at 550 and 600°C and second-grade wood charcoal standards at other temperatures. However, higher concentrations of some heavy metals like Zn indicate the need for pretreatment and further research on co-pyrolysis for resource optimization. This study highlights the dual benefits of waste management and renewable energy, providing insights for urban planning and policymaking.

Springer — Fossil fuel depletion and environmental concerns necessitate sustainable energy alternatives. Biomass, being abundant and carbon neutral, is a promising option. This study compares the effects of calcium carbonate (CaCO₃) and eggshell additions to biomass under identical pyrolysis and combustion conditions. Rice chaff and corncob were mixed with 2, 5, and 10% CaCO₃ or eggshells and pyrolyzed at 300 °C and 500 °C. Thermogravimetric analysis showed improved thermal stability, especially at higher mixing ratios. Elemental and proximate analyses revealed reduced carbon, hydrogen, and oxygen with increased ash, while FT-IR confirmed structural changes. A 2% mixing ratio best preserved combustion indices. Corncob-based samples at 300 °C exhibited excellent performance, with a calorific value of 28.20 MJ/kg and 66.58% energy yield. The findings indicate that eggshells, an accessible biowaste, perform comparably to commercial CaCO₃ in enhancing fuel properties. Their cost-free and eco-friendly nature makes them a viable biomass additive. Further research should explore industrial-scale applications and other calcium-based biowaste materials for optimisation.

PLOS ONE — Thermochemical processes employ heat to transform biomass into energy. In these processes, heat supply and biomass type can affect the products, therefore understanding them is critical. Confirming these changes directly requires time and resources. Several hypotheses have been proposed to explain these changes. So, the purpose of this work was to investigate mass loss during thermochemical reactions utilising available kinetic parameters. This study comprised previously pyrolysed herbal agricultural biomass (soybean pod, corncob), woody agricultural biomass (pepper stem, grape pruning branch), and forestry biomass (wood pellet, bamboo). Temperature fluctuations were studied using a 1D temperature prediction model and evaluated using kinetic parameters. The findings anticipated using prior research’ kinetic parameters differed by up to 20% from the experimental results. As a result, some of the kinetic parameters were adjusted. The prediction model with the changed parameters outperformed the prior results, with an RMSE of 2.0607 for wood pellets and 5.9754 for soybean pods. The results obtained using grape pruning branches, bamboo, and corncobs confirmed the mass reduction predicted by prior studies. This study revealed the capacity to estimate mass loss without using thermogravimetric measurements, and future predictions should include a broader spectrum of biomass materials.

ScienceDirect — This study investigates the feasibility of utilizing agrobyproduct biochar as a substitute for fossil fuels in thermal power plants by comparing oxygen-rich and oxygen-lean pyrolysis processes. The biomass types examined include soybean pods (BE), bamboo (BB), and wood pellets (WP). Results demonstrate that oxygen-lean pyrolysis at high temperatures enhances biochar's carbon content and energy density. Mass yields varied, with WP showing the highest yield at 500℃ under oxygen-lean conditions. Elemental analysis indicated increased carbon content and improved fuel properties with higher pyrolysis temperatures. Proximate composition analysis revealed decreased volatile matter and increased fixed carbon and ash content, leading to higher fuel ratios. Calorific values increased significantly across all biomasses, particularly under oxygen-lean conditions. Gas analysis showed significant changes in O2, CO2, and CO concentrations with temperature variations. Combustion indices and physical properties like aromaticity and Hardgrove grindability index improved with higher temperatures. Optimal pyrolysis conditions were identified as 325℃ for WP, 350℃ for BB, and 300℃ for BE, with BE also performing well at 500℃. The study concludes that optimized agrobyproduct biochar can effectively replace conventional fossil fuels, offering high energy yield and enhanced combustion properties.

kstudy.com — The increase in fossil fuel use, brought about by industrial growth, and its adverse effects on climate change through increased CO 2 emissions and environmental pollution, were addressed in this study. The aim of this study was to further reduce dependence on fossil fuels and their adverse effects on the environment by evaluating alternative energy sources, such as biomass.

Springer — Purpose Nepal, with its diverse geography of flat lowlands (Terai), Hills, and Mountains, primarily focuses on rice farming, especially in the Terai and Hilly regions. This leads to varying farming patterns, inputs, and yields. This study filled the research gap in analyzing the spatial heterogeneity in energy use patterns, emissions, and the economics of rice farming in Nepal. Methods The study is conducted by collecting primary data through structured face-to-face interviews with 100 rice farmers. The data collected through the survey is analyzed using the literature to understand the energy, emissions, and costs associated with rice farming. Results The net energy, yield, productivity, and energy use efficiency were found to be 67,540 MJ ha−1, 5,720 kg ha−1, 0.47 kg MJ−1, and 6.52, respectively, for Terai, which is higher than that of the Hill, i.e., 46,932 MJ ha−1, 4,098 kg ha−1, 0.43 kg MJ−1, and 5.90 respectively. The econometric model highlighted mechanization as most impactful on paddy yield, and sensitivity analysis suggested that 1 MJ of additional machinery or seeds per ha boosts yield by 0.97 and 0.96 kg, respectively. In Terai, the profit per hectare and benefit–cost ratios were found to be USD 205 and 1.32, while in Hill, negative earnings of USD 42 ha−1 and 0.95 the benefit–cost ratios were found. Despite lower emissions, Hill had higher carbon efficiency (7.78) than Terai (5.67). Conclusion The study found Terai to be energy efficient and profitable but more emissive than Hill. These findings provide valuable insights for policymakers, researchers, and agricultural experts interested in the energy, economics, and emissions of rice farming in Nepal.

ScienceDirect — Agricultural crop residues are the lignocellulosic biomass left in the field after harvesting valuable crop parts. These pose a significant concern due to the waste generated annually, burdening management and contributing to pollution. Numerous studies carried out over decades have demonstrated some effective utilization through thermochemical conversion as a potential feedstock, there is not a proper account of their trends. This systematic review addresses a critical gap in the literature by analyzing the sustainable management of crop residues thermochemically, offering insights into research trends, technologies, and future directions for their utilization as biofuel and bioactive value-added-product applications, that has been largely overlooked in previous narrative reviews. Studies for review were searched on web of science, scopus, and google scholar through a carefully developed search syntax and backward snowball methods. Total 343 papers published in past 23 year matched the study inclusion criteria were selected and meaningful outcomes from meticulous analysis of these studies have been extracted. Research publications show exponential growth, primarily focused on laboratory-based experiments. The most studied process was pyrolysis, and the product was biochar. There has been significant progress in process optimization, integration, and product diversification, paving the way for diverse applications. Recent trends indicate a shift from conventional pyrolysis and gasification towards sustainability, circular economy, efficiency enhancements, and novel applications, reflecting a broader commitment to environmental stewardship and resource maximization. Additionally, the challenges linked with recent innovations are discussed, along with recommendations for future research endeavors concerning these systems.

kisanaawaj.com — 372Sharesबर्दिया : सिमिट इन्टरनेशनलद्वारा संचालित सिसा परियोजनाले क्वालिटी एग्रो सप्लायर्स भुरिगाउँको सहकार्यमा ठाकुरबाबा नगरपालिका २ कर्मालामा १ दिने कृषि यन्त्रको समस्या निवारण तथा सम्भार तालिम सम्पन्न गरेको छ । कोभिड १९ को महामारी पश्चात विदेशमा आफ्नो रोजगारी गुमाएर नेपाल फर्किएका युवाहरूलाई स्वदेशमा नै कृषिमा व्यवसाय गर्ने तथा मेसिनरी सेवा प्रदायकको रूपमा काम गर्न कृषि मेसिनहरू [...]

paudelpadamprasad.wordpress.com — ★★के हो त यो ग्रेडिङ सिस्टम??★ हाल एसएलसी रिजल्टको ग्रेडिङ सिस्टम धेरैजसोले बुझेका छैनन्। बुझ्न खोज्नेले पनि गलत गरिकाले बुझेर झुटो प्रचार गरिरहेका छन्। खासमा यो ग्रेडिङ पद्धति के हो? यसको आवश्यकता किन पर्यो? यो ग्रेड पोइन्ट कसरी मापन गरिन्छ? यसरी पाएको ग्रेड पोइन्टलाई कसरी पुरानो तरिकामा बदलेर नम्बर तथा प्रतिशत निकाल्न सकिन्छ??

halokhabar.com — हामी सबैलाई थाहा नै छ, अहिले असारको महिना। नेपालको धेरैजसो ठाउँमा धान रोप्ने चटारो छ । नेपालको अधिकांश खेतहरूमा परम्परागत रूपबाट नै ज्यामि लगाएर धान गरिन्छ भने केही ठाउँमा सिडड्रिल मेसिन वा हातैले धान छरेर छरूवा धान खेति पनि गरिन्छ । केही वर्ष यता रहरकै लागि भएपनि नेपालमा धान रोप्ने मेसिन राइस ट्रान्सप्लान्टर आयात गरेर प्रदर्शन तथा प्रयोग भइरहेका छन् । तैपनी सोचे अनुरूप अबलम्बन हुन सकेका छैनन् । नेपालमा अहिलेसम्म धान रोप्ने मेसिनहरूको संख्या १०० पनि नकटेको सिसापरियोजनाको अनुमान छ । त्यसमध्ये १५/२० वटा मात्र चालु अवस्थामा रहेका होलान् । धेरै जसो तिन चक्के बस्ने भएको, केही दुई चक्के पछाडी हिड्ने प्रकारको र केही इन्जिन बिना मान्छेले नै चलाउने म्यानुअल खालका देख्न सकिन्छ । हालसालै ७७/७८ मा चार चक्के धान रोप्ने राइस ट्रान्सप्लान्टर मेसिन प्रति आकर्षण बढेको देखिन्छ ।

blogspot.com — Blog contains Note, Book, Thesis, Old question, Solution, Photos, Videos and all kind of material of Agricultural Engineering. #Nepal, #IOE, #TU

ratopati.com — सङ्घर्षका दौडाइको क्रममा विभिन्न समयमा विभिन्न व्यक्तिहरुसँग भेट हुन्थ्यो । नयाँ मानिससँग भेट हुँदा प्रायः हाम्रो दोहोरो परिचयबाट कुरा सुरु हुन्थ्यो भने कति ठाउँमा म एक्लैले मात्र परिचय दिनुपथ्र्यो । परिचयका क्रममा धेरै ठाउँमा नाम, ठेगाना, पेसा बताइसकेपछि प्रत्येक पटक एउटा प्रश्न आउँथ्यो- तिम्रो बाबा के गर्नुहुन्छ ?'

onlinekhabar.com — पदमप्रसाद पौडेल ड्याङ ड्याङ ड्याङ ड्याङ, को आयो यो मध्यरातमा? ढोका खोले बिम्झिएर, तर्सिहाले देख्दा उ साथमा, किन आएको यति राति ? को हौ तिमी? म नया बर्ष चिनिनौ २०१६ को सिमी साच्चै के तिमी नै हौ त नया बर्ष ...

https://www.arghakhanchi.com/ — म त्यो बेलासम्म धेरै नै नगरहरु घुमिसकेको थिए। ती घुमेका धेरै नै नगर सबै फोहोर नै फोहोरले भरिएका थिए । त्यहा रहेका हरेक खोला नालाले अमृतरुपी जल बोक्नुको सट्टा कालो गन्याउने बाक्लो लेदो बोकेका हुन्थे । त्यस्तैमा मलाई लाग्थ्यो। बजारै भरी दुर्गन्ध फैलाउदै हिड्ने नालीलाई के थाहा यही नालीमा बगेको पानीले अरुलाई कति पीडा दिइरहेको छ भन्ने कुरा।

www.padamprasadpoudel.com.np — Mechanization Overview (Introduction, Objective) Modernization is an appropriate use of new technology approved by science that should be suitable to all place, acceptable to all, fast, cheap, convenient, reliable flexible and impacting positive impression to society. Commercialization is use of modern technology to provide goods and service in public market for the purpose of profit and service. Agricultural Mechanization is utilization of Agricultural Engineering principle and theories for the modern and commercialized development of Agriculture. It includes foods crops, grasses and feed for animal, Rubber, fiber and cotton production, bio-fuel plant production, conservation, processing, transportation, storage, and distribution works. In this way, simple machinery to modern machinery and technology are used to make the simple, fast, cheap, convenient and efficient the agricultural operation over physical works.

www.kisanaawaj.com — 106Sharesधनुषा : कृषि यान्त्रीकरण प्रवर्द्धन केन्द्र, कृषि यन्त्र परीक्षण तथा अनुसन्धान केन्द्र र नेपाल कृषि इन्जिनियर्स सोसाइटीसँगको सहकार्यमा अन्तराष्ट्रिय मकै तथा गहुँ सुधार केन्द्र (सिमिट) को सिसा र रोडम्याप परियोजनाहरूको संयुक्त आयोजनामा 'कृषि यान्त्रीकरण प्राविधिकहरूको क्षमता अभिवृद्घि तालिम' सम्पन्न भएको छ । चैत्र २४ देखि २८ गते सम्म संचालनमा रहेको प्रदेश नं.

www.sudurdaily.com — धनगढी,२ फागुन-कञ्चनपुरमा नेपालमै पहिलो पटक कम्बाईन हारर्भेष्टर मर्मत सम्बन्धी तालिम सुरु भएको छ ।

Springer — Purpose We investigated the energy usage, economics, and global warming potential (GWP) of spring rice production via farm sizes in Nepal. Methods Seventy farmers were selected via purposive sampling methods, and data were collected by interviewing the farmers on site.

hcommons.org — Power tiller operated reaper operation, repair and maintenance information booklet. That is mostly useful for harvesting the rice and wheat. It's based on 4GL120 modal vertical conveyer reaper. This booklet was prepared by a group of extension workers working on Cereal system Initiative for south asia project of International Wheat and maize improvement centre Nepal.

researchgate.net — Solar lift irrigation is the effective alternative to agricultural irrigation that runs with the electricity generated by photovoltaic modules. This uses an electric motor coupled with pump and powered from solar array through motor's drive. The studied Devdas Krishi Farm Solar lift irrigation project is technically feasible, economically viable and effective for sub-surface water pumping. Designed system uses 2 horse power three phase motor pump monoset driven through an 2.2 KVA ac drive operated from 2120 watt solar array. The targeted output average discharge is 2 lakhs 20 thousand liters per day and the estimated cost of the project is NRs 5 lakhs 70 thousand three hundred thirty-nine.

Setopati — हाल यो ग्रेड पोइन्ट लाई ४ ले भाग गरी १०० ले गुणा गरेर प्रतिशत निकाल्ने गरेको पाइन्छ तर यो तरिकाले प्रतिशत निकाल्ने पद्धति गलत हो। साधारण तरिकाले प्रतिशत निकाल्न देशभरबाट सम्बन्धित बिषयमा उच्च नम्बर ल्याउने विद्यार्थीको नम्बर पत्ता लगाएर त्यसबाट आफ्नो ग्रेड पोइन्टलाई नम्बरमा र नम्बरलाई प्रतिशतमा बदल्न सकिन्छ। यसरी निकालेको प्रतिशत हामिले गलत तरिकाले निकालेको प्रतिशत भन्दा अवश्य कम हुन जान्छ। त्यसैले कसैले जिपिए ४ ल्यायो भने उसले १००% ल्याएको मानिदैन तर उसको नम्बर/स्तर तुलनात्मक तरिकाले सर्वश्रेष्ठ मानिन्छ।