Increase In Total Production Research Articles

Harnessing Soil Diversity: Innovative Strategies for Potato Blight Management in Central-Eastern Poland

Faced with increasing climate challenges, this pioneering study introduces groundbreaking approaches to ensure the resilience of potato crops in east-central Poland. Our research was aimed at developing an innovative, cost-effective system tailored to the diverse local conditions of this region. Conducted between 2018 and 2020, the study analyzed integrated and organic production systems across different soil types and potato varieties. The experiment was conducted using a randomized block design with three replications in two locations. Integrated production systems involve the strategic use of mineral fertilization and chemical protection to optimize crop growth and health, whereas organic production systems rely solely on natural inputs and biological pest control methods. Integrated practices, enhanced by mineral fertilization and chemical protection, notably delayed the onset of late blight by 16 days and extended the critical infection period by 17% compared to their organic counterparts. Remarkably, the integrated systems resulted in a 49% increase in total production and a 52% increase in commercial yields, demonstrating their effectiveness in enhancing crop resilience. Different potato varieties exhibit varied responses to cultivation systems, influencing both yield and disease resistance. Further investigation into these varietal responses can help optimize cultivation practices, leading to improved efficiency and sustainability in potato farming. Location and soil conditions have a significant impact on potato yield and the spread of potato blight. Specific soil properties such as pH levels, organic matter content, soil texture (clay, silt, and sand composition), moisture retention capacity, and nutrient availability are crucial in determining potato productivity and disease dynamics. Further research into these soil properties and the adaptation of varieties to local conditions can contribute to increased productivity and stability in potato production. This study not only paves the way toward sustainable agriculture but also highlights the crucial role of soil diversity in shaping resilient farming practices. Potato producers in the eastern-central region of Poland should implement integrated production systems using mineral fertilization and chemical plant protection, adapted to local soil conditions and potato varieties. These practices can delay the appearance of late blight and increase the total and marketable potato yield. Further research on soil properties and variety adaptation may increase production stability and efficiency. Promoting soil diversity and modern technologies will ensure resilient and sustainable agricultural production in the face of climate change.

Improving Water Use Efficiency and Economic Benefits of Cropping System Through Intercropping in an Arid Climate

The sustainable increase of total productivity by improving resources use efficiency in arid agricultural farming areas is crucial, and intercropping may be a good practice to be implemented in these arid regions. For this purpose, a three-year field experiment was conducted as a randomized complete block design (RCBD) with three replications at the research farm of the Agricultural and Natural Resources Research Station of Gonabad, Gonabad, Iran to assess the agronomic and economic indices of intercropping patterns. The experiment treatments included C1: sole cotton, C2: sole sesame, and intercropping ratios (C3: 20:80, C4: 40:60, C5: 50:50, C6: 60:40, and C7: 80:20 cotton-sesame ratio). The results showed that the leaf chlorophyll content and leaf area index were significantly higher in the intercropped plants compared to the sole cropped plants. The yield components of both crops (such as branches per plant, capsules per plant, seeds per capsule, and 1000-seed weight for sesame, and opened bolls per plant, closed boll per plant, and seed cotton per boll for cotton) significantly improved under intercropping. However, the highest sesame seed yield (2703, 1979, and 1358 kg ha-1, respectively) and seed cotton yield (3749, 2179, and 3426 kg ha-1, respectively) in the three experiment years were observed in the sole cropping treatment. The implementation of intercropping significantly improved the water use efficiency of the cropping system, so that the highest values in the first to third year (0.67, 0.51, and 0.41 kg m-3, respectively) were recorded in the C4, C3, and C7 treatments. The intercropping evaluation indices revealed the advantage of intercropping compared to the sole cropping. The highest value of the land equivalent ration in the first year (1.28) belonged to the C4 treatment, while in the second and third years, belonged to the C7 treatment (1.40 and 1.10, respectively). The calculation of the aggressivity index revealed that in most of the intercropping patterns, especially in the first and second years, cotton showed greater competitive ability than sesame. The highest actual yield loss value in the first year (0.64) belonged to the C3 treatment, while in the second and third years, belonged to the C7 treatment (1.42 and 0.34, respectively). The highest economic advantage in terms of the monetary advantage index in the first year was obtained by the C4 treatment (1140.5), and in the second and third years, was observed in the C7 treatment (940.6 and 265.5, respectively). The intercropping advantage index in the three experiment years was highest (1.41, 3.38, and 0.80, respectively) for the C7 treatment. Eventually, the results of this research show that cotton and sesame are able to adapt well to the intercropping and this cropping system can significantly improve the resources use efficiency (especially water and land) in an arid area enjoying greater economic benefit than sole cropping

Optimal Worker Allocation of Food Manufacturing System using Simulation and Data Envelopment Analysis

This study suggests employing simulation and data envelopment analysis to support decision making for determining the optimal worker allocation for a food manufacturing production line. The simulation model for food production is based on a real-world example from the food industry, focusing on a manufacturing company. The challenge faced by the company involves a constrained number of workers allocated to four processes. The imbalance number of workers in each process will affect the productivity of the company. Through simulation modeling of the actual systems, it was discovered that the filling process presents a bottleneck due to its significantly higher average waiting time compared to the other processes. A valid simulation model was subsequently employed to generate potential improvements. Nineteen improvement models were proposed and assessed based on various selection criteria, including average total production time, average number of entities still in the system, total production, and average resource utilization. Among the nineteen improvement models, Improvement Model 11 (IM11) emerged as the best improvement model. The optimal worker allocation alternative involves assigning two workers to each process, leading to anticipated increases in total production and average resource utilization. Utilizing simulation and data envelopment analysis can help the management of the company to make better decisions in determining the optimal worker allocation.

РАЗВИТИЕ СЕЛЬСКОГО ХОЗЯЙСТВА РОССИИ И НАПРАВЛЕНИЯ ПОВЫШЕНИЯ ЕГО КОНКУРЕНТОСПОСОБНОСТИ НА МЕЖДУНАРОДНОМ РЫНКЕ

The agriculture of the Russian Federation is an important part of the national economy, the basis for ensuring the country’s food security. The development of agriculture is influenced by both internal factors (climate, economy, labor resources, state support for the industry, etc.) and external factors (sanctions from unfriendly countries, world market prices, etc.). The importance of increasing the competitiveness of the Russian agricultural industry in the international market has increased with the launch of a special military operation in 2022, as it has faced new challenges. As a result of large-scale political pressure from unfriendly states, the country was cut off from imports of equipment, spare parts, technologies and seeds necessary for the agro-industrial sector, supply chains were disrupted, prices for imported goods increased, and problems arose with exports. Despite these difficulties, Russian agriculture, despite the decline in crop production, due to the growth of indicators in dairy and meat animal husbandry, shows a steady increase in total production. So, in comparison with 2017, the volume of milk production by 2021 increased by 7%, and meat of all types - by 10%. The level of self-sufficiency of the Russian Federation in 2021 exceeded the threshold levels of the Food Security Doctrine for the production of grain, sugar, meat and meat products; below the threshold level was the production of potatoes, milk and dairy products, vegetables and gourds, fruits and berries. Also, a positive moment in the development of the agricultural sector is the increase in the volume of exports of the industry’s products both in kind and in monetary terms, the structure of exports has improved, where there are more and more products of processed agricultural raw materials. However, at present, the sanctions of unfriendly countries have a negative impact on the development of agriculture in the Russian Federation and on its competitiveness in the international market. To solve the problems of the industry, it is necessary to strengthen state support for agricultural producers, aimed at increasing investment and innovation activity in the industry, developing import substitution (creating new industries) and ensuring food security.

RELAYOUT LANTAI PRODUKSI SPRINGBED MENGGUNAKAN METODE SLP, CORELAP SERTA SIMULASI PROMODEL, DAN FLEXSIM

PT. Alpha Jaya Manunggal Mandiri is manufacturing company engaged in furniture sector. There are several problems with old layout such high material handling costs, long distances between work stations, and alternating flow. Therefore, relayout and lean manufacturing approach were carried out. Alternative layouts made using SLP method, and CORELAP. The initial steps in making alternative layouts are measuring floor area, making production flows, and measuring production standard times. Next step is forecasting product demand for next 10 years for routing sheet. Routing sheet used to determine number of machines needed to meetproduct demand. Alternative layout was created using 2 methods. Based on alternative layout, material handling costs and moving moments are calculated to find layout with minimum material handling costs and moving moments moments. The selected layout is alternative layout SLP method cause it reduces material handling costs by 50.12%, moving moments by 17.86%, and distance by 53.42%. Then lean manufacturing approach carried out to increase productivity. A simulation was carried out with Promodel and Flexsim software to simulate new and old layout to find product improvements using new layout. Based on Promodel simulation, there was decrease in the average time in system by 21.82%, decrease in the average time in operation by 22.36%, and increase in total production by 15.29%. Based on Flexsim simulation, there was increase in amount of daily production by 58.52%, and decrease in staytime by 33.47% per product. Through research, it can be concluded that layout can be implemented as new layout on springbed production floor.

Impacts of Green Energy Expansion and Gas Import Reduction on South Korea’s Economic Growth: A System Dynamics Approach

South Korea, ranking ninth among the largest energy consumers and seventh in carbon dioxide emissions from 2016 to 2021, faces challenges in energy security and climate change mitigation. The primary challenge lies in transitioning from fossil fuel dependency to a more sustainable and diversified energy portfolio while meeting the growing energy demand for continued economic growth. This necessitates fostering innovation and investment in the green energy sector. This study examines the potential impact of green energy expansion (through integrating renewable energy and hydrogen production) and gas import reduction on South Korea’s economic growth using a system dynamics approach. The findings indicate that increasing investment in green energy can result in significant growth rates ranging from 7% to 35% between 2025 and 2040. Under the expansion, renewable energy scenario (A) suggests steady but sustainable economic growth in the long term, while the gas import reduction scenario (B) displays a potential for rapid economic growth in the short term with possible instability in the long term. The total production in Scenario B is USD 2.7 trillion in 2025 and will increase to USD 4.8 trillion by 2040. Scenario C, which combines the effects of both Scenarios A and B, results in consistently high economic growth rates over time and a substantial increase in total production by 2035–2040, from 20% to 46%. These findings are critical for policymakers in South Korea as they strive for sustainable economic growth and transition to renewable energy.

Modernization of the Coal Industry of the Far East during the First Five-Year Plan (1928–1932)

Introduction. The coal industry of the Far East, which was the main fuel base of the region, was in a state of severe crisis by 1928. The enterprises of the industry did not have the necessary working capital, were equipped with obsolete equipment, experienced an acute shortage of qualified personnel. The solution of these problems became possible with the beginning of industrialization in the USSR and the provision of assistance to the region by the center. Materials and Methods. The source basis of the research is unpublished documents identified in the funds of federal and regional archives. In the course of the work, the author used a set of general scientific and special historical methods. Results and Discussion. During the implementation of the first five-year plan, the financing of coal mining in the Far East has sharply increased. At the mines of the region, the active introduction of the latest technology began, which made it possible to begin mechanization of production processes, increase the level of electrification and mechanization. The foundations of the personnel training system were also laid, significant labor resources from the central regions were attracted. However, despite the successes achieved: an increase in labor productivity, an increase in total production, the final results turned out to be more modest than expected. Basically, the changes covered the enterprises of Primorye, on Sakhalin and in the Amur region, reconstruction was carried out much slower. Conclusion. The reasons that caused the divergence of plans and the results obtained in practice were the periphery of the region, which led to its supply on a residual basis and ignoring its interests in favor of more industrialized areas. As well as underestimating the production capabilities of the enterprises themselves, the geological conditions of their operation. In 1928–1932, it was not possible to create a stable supply system for equipment and machinery, low qualifications and high turnover of labor remained.

Integrated multitrophic aquaculture system applied to shrimp, tilapia, and seaweed (Ulva ohnoi) using biofloc technology

Integrated multitrophic aquaculture (IMTA) is a model that integrates organisms from different trophic levels, all sharing the same production system and, consequently, the nutrients. This study adopted shrimp (Penaeus vannamei) as the main species, tilapia (Oreochromis niloticus) as an organic consumer, and the seaweed (Ulva ohnoi) at different densities as an inorganic consumer in a biofloc production system. The study consisted of an experiment with three treatments and four replicates each: 1) No seaweed; 2) Seaweed 1 g L−1 (density of 1 g L−1 of U. ohnoi), and 3) Seaweed 2 g L−1 (density of 2 g L−1 of U. ohnoi). Shrimp (3.82 ± 0.05 g) were stocked in 800 L tanks at a density of 275 shrimp m−3, fish (14.44 ± 0.57 g) in 90 L tanks at a density of 267 tilapia m−3, and 50 and 100 g of seaweed stocked in 50 L tanks, corresponding to treatments with 1 and 2 g L−1, respectively. The integration of U. ohnoi at densities of 1 g L−1 and 2 g L−1 with P. vannamei and O. niloticus benefited the system through higher nitrogen (13,22 and 13,10% higher in the treatments 1 g L−1 and 2 g L−1 respectively) and phosphorus recovery (25,57 and 34% respectively) and an increase in total productivity (15,32 and 19,22% respectively), generating an ecological gain. Considering the similar final biomass of seaweed in a multitrophic system with shrimp and tilapia, the use of U. ohnoi at a density of 2 g L−1 is recommended since nutrient recovery by fish and shrimp was higher at this density.

Effect of Nitrogen Supplementation additives at Casing on the Productivity and Quality of the mushroom Agaricus bisporus

This study aims to assay the effect of the separate supplementation with 1, 3 and 5% of (Erbil Feed, WAFI HOLAND, Lysine, Methionine, Ammonium Chloride and Calcium Nitrate) at casing on the productivity and quality of the mushroom Agaricus bisporus. Results indicated a significant increase in total production and biological efficiency. with treatment of 1% Erbil Feed. When total production increased from 21.68 kg / m2 in the control to 23.20 kg / m2 with this supplement. While the biological efficiency was increased from 72.26% to 77.33% with the same supplement. Treatment 1% of Erbil Feed was also recorded earliest production reached at 16 days after casing than controls at 18 days. The qualitative traits of 3% Methionine has recorded higher of total antioxidants contents at 1975 µg/ g dry weight comparison with control, which was 1572 µg/ g dry weight, as well as recording the 3% of Erbil Feed gave a higher protein contents 36.85% compared to the control treatment 22.36 %.

Performance of Leafy Vegetables Intercropped With Brinjal

An experiment was conducted during rabi and kharif season of 2018 - 2019 and 2019-2020, respectively at Regional Agricultural Research Station (RARS), Cumilla to find out the suitable crop combination of leafy vegetables with brinjal for increasing productivity and economic return through intercropping system. Five treatments viz. Brinjal + Red amaranth (T1), Brinjal + Leaf amaranth (T2), Brinjal + Patshak (T3), Brinjal + Spinach (T4) and Sole crop of brinjal (T5) were used in rabi season. In kharif season all the treatments were same except T4 where Indian spinach was used with brinjal instead of spinach. Results showed that yield and yield contributing characters of brinjal did not differ significantly due to different intercropping systems. Yield of brinjal was comparatively low in intercropping but total productivity increased due to additional yield of leafy vegetables. Increase of total productivity in terms of brinjal equivalent yield (BEY) was 2.03 to 25.68% (Rabi) and 2.36 to 22.29% (Kharif) and in intercrop combination compared to sole crop. All the intercropping combinations showed higher brinjal equivalent yield (BEY), gross return and benefit cost ratio (BCR) over sole crop. Among the intercropping combinations, Brinjal + Spinach (rabi) and Brinjal + Indian spinach (kharif-1) was the most feasible and profitable in respect of BEY (48.94 and 27.62 t/ha, respectively), gross return (Tk. 1223400 and 1105000/ha, respectively), gross margin (Tk.908823 and 782487/ha, respectively) and benefit cost ratio (3.88 and 3.42, respectively). Bangladesh J. Agril. Res. 46(1): 89-97, March 2021

Increasing land productivity with agriphotovoltaics: Application to an alfalfa field

Agriphotovoltaic systems, consisting of the combination of crops and photovoltaic panels (PVPs) on the same area, have recently emerged as an opportunity to solve the competition for land use between food and energy production. Various crops, pedoclimatic contexts and structures and both fixed and mobile panels have been studied. Over a period of two years, this research has been investigating an agriphotovoltaic (APV) system with mobile panels along two axes of rotation. The studied crop is alfalfa, a grassland species that has received little attention under these conditions. In our experimental set-up, the alfalfa biomass increased by an average of 10 % over the two years of the experiment in the shade of the APV plant (between 29 % − 44 %) in comparison to full sunlight (835 g.m−2.year−1), but in a different way depending on the climatic year. The nutritional qualities were preserved while the canopy's morphology was adapted through an increase in the length of the stems and the surface area of the leaflets. Photovoltaic production was reduced by 15 % due to the optimised tracking for plant growth. This combined production allowed an increase in total productivity per unit area of 51 % (LER: 1.51). The positive agronomic results are explained by a decrease in evapotranspiration caused by the panels in a context where the crop is highly sensitive to water deficit with thin soil. To reach a more general conclusion on synergy, these results need to be completed over several years and compared with other studies in different soil and climatic contexts, as well as with modelling studies.

Empirical analysis of strategy selection for the technology leading and technology catch‐up in the IT industry

AbstractR&D strategies of companies with low and high technological levels are discussed based on the concept of technology convergence and divergence. However, empirically detecting enterprise technology convergence in the distribution of enterprise technology (total productivity increase) over time and identifying key change factors are challenging. This study used a novel statistical indicator that captures the internal technology distribution change with a single number to clearly measure the technology distribution peak as a change in critical bandwidth for enterprise technology convergence and presented it as evidence of each technology convergence or divergence. Furthermore, this study applied the quantitative technology convergence identification method. Technology convergence appeared from the separation of total corporate productivity distribution of 69 IT companies in Korea in 2019–2020 rather than in 2015–2016. Results indicated that when the total technological level was separated from the technology leading and technology catch‐up, IT companies were found to be pursuing R&D strategies for technology catch‐up.

Process optimization of conventional steam distillation system for peppermint oil extraction

ABSTRACT This study aims to optimize peppermint oil extraction process using response surface methodology (RSM). Experiments were performed for different batch sizes (1500, 1700, and 1900 kg). System performance was evaluated in terms of thermal efficiency, productivity, essential oil yield (EOY), extraction efficiency, and CO2 emissions. Total energy consumption for 1500, 1700, and 1900 kg batch sizes are 1379.46, 1336.58, and 1286.56 kWh, while CO2 emissions are 1104, 1069, and 1028 kg, respectively. Maximum hourly system productivity, cumulative productivity, maximum hourly thermal efficiency, maximum extraction efficiency, and maximum EOY were obtained as 8.3 L/h, 20 L, 2%, 41.5%, and 0.461% (w/w), respectively, for 1900 kg. Average increase in total productivity, extraction efficiency, and EOY was 49.25%, 1%, and 26%, increasing in batch size from 1500 kg to 1900 kg. Extraction time and batch size have important effect (p < 0.001) on the extraction yield. Optimal process parameters are identified 300 min of extraction time and 1807.5 kg of batch size. The highest oil yield was 1.0614% under optimal conditions. Experiment was further performed for 1807.5 kg of batch size and the yield was found as 1.04621. Predicted and experimental results were found in good consistency with percentage deviation of 1.436. Therefore, this is helpful in conducting further research on optimizing process parameters for conventional distillation system of peppermint oil extraction.

Peculiarities of formation of oxygen productivity of broadleaved stands in kyiv region under diverse forest growth conditions

The research presents the results of assessment of oxygen productivity of deciduous stands in Kyiv city and Kyiv region as one of the basic ecosystem functions of forest plant communities in urban conditions. Quantitative assessment of oxygen productivity is based on the use of a "semi-empirical" method of evaluation of net primary production, which considers it as an analogy to the annual increase in total productivity of live biomass (or total live biomass growth). In total, the assessment of oxygen productivity of forests in Kyiv region covers the forested area of over 75 thousand hectares in twenty-one type of forest growth conditions. We have established that deciduous forests in Kyiv region produce more than 4 million tons of oxygen annually, at the same time the mean oxygen productivity in the studied stands is more than 17 t·ha-1·year-1. Almost 75% of these oxygen volumes are produced by hardwood stands. Peculiarities of formation of forests’ oxygen productivity in different types of forest growth conditions have been determined within this research. In particular, forest plant communities in fairly infertile conditions (1.98 million tons) account for almost 50% of oxygen produced, including more than 1 million tons of oxygen produced by stands in fresh fairly infertile conditions (C2). A significant influence of forest growth conditions type on the indices of intensity of oxygen productivity in the studied stands was established. The highest values of mean oxygen productivity are typical for plantations in fresh fertile and fairly fertile conditions – 26.9 and 23.2 t·ha-1·year-1, respectively. Net oxygen productivity in these types of forest growth conditions is 10.8 and 8.9 t·ha-1·year-1, respectively. The obtained results serve as an information basis for ecological monitoring of the impact of forest ecosystems of the region on the state of recreational potential in Kyiv region.

The utilization of plant growth-promoting bacteria to enhance stevia (Stevia rebaudiana) herb yield at low land

Stevia is a native crop of sub-tropical regions; its cultivation is extended to low land tropical regions, which might the growth is not good as in its origin growth areas. Bacteria as growth promoters are expected to enhance stevia growth in low-land tropical regions. This study aimed to determine the effect of bacteria on the growth and yield of stevia. The research was conducted at the Microbiology Laboratory and Greenhouse of the Indonesian Spices and Medicinal Crops Research Institute at 240 m above sea level and was arranged in a complete randomized block design with four replications. The treatments consisted of 1) control, 2) rhizosphere bacteria Brevibacillus parabrevis GF13, 3) endophytic bacteria Mesorhizobium soli NHI-8, 4) endophytic bacteria Bacillus pacificus EB422, 5) a combination B. parabrevis GF13 + M. soli NHI-8, and 6) a combination of Br. parabrevis GF13 + B. pacificus EB422. The highest increase in total production of fresh (32.8%) and dry (25.86%) herbs were found in treatment 4 (endophytic bacteria Bacillus pacificus EB422). The treatment caused the plant to have the highest nutrient uptake 0.124 N g/plant, 0.051 P2O5 g/plant, and 0.172 K2O g/plant. The treatment increased soil chemical properties.

Prospects for cotton self-sufficiency in China by closing yield gaps

Although China is the world second largest cotton (Gossypium hirsutum L.) producer, it is the world largest cotton consumer with high reliance on import. Cotton cropping system in China underwent substantial changes in the past few decades as 85% of the previous cotton area changed into other uses, and its production center has shifted fast to new croplands in Xinjiang where farm size is larger and mechanization more prevalent. Given these rapid changes, we performed the first comprehensive assessment of cotton production capacity and self-sufficiency ratio in China based on the analysis of yield gap (difference between current farm yield and yield potential) by employing a bottom-up scaling approach which entails local weather, soil, crop management and latest high-yielding experimental data. We found that current yield gap represents 40% of estimated potential yield, suggesting a large scope for total production increase by yield gap closure. China’s current cotton self-sufficiency ratio is 68%, and it could reach 90% by yield gap closure in Xinjiang alone and up to 94% in all major cotton growing provinces by 2030. Results also highlight the regions with the greatest prospect for further production increase in China by considering current yield gaps, production area, and potential for expansion. Xinjiang alone could achieve 71% of additional production, while opportunities also exist in the other major cotton growing provinces, i.e., south part of Hebei and southeast part of Hubei provinces.

Developing new lines of Japonica rice for higher quality and yield under arid conditions.

Rice is the world’s largest food crop, and its production needs to be doubled by 2050 to cope with population growth and associated demand. In addition to the value of improving yields, quality is also important for breeders and consumers, but it pays less attention in arid regions. During two successive summer growing seasons, the experimental material focused on 34 genotypes developed from different crosses on Fn generation after fixation as well as six of the most recent commercial cultivars used for comparisons. The results showed that a high yield of grain followed by high milling and grain quality characteristics were observed among the 34 genotypes used in this analysis. Highly important and positive correlations between the percentage of hulling and the percentage of milling (0.424) and the yield ability could be accomplished by choosing the number of panicles per plant and the weight of the panicles. Selection criteria for good quality should be met by the percentage of head rice and many mineral elements, particularly zinc and iron. As a consequence, the genotypes M.J 5460S/SK105-1, M.J 5460S/GZ7768-1, M.J 5460S/G177-1, M.J 5460S/SK105-3 and M.J 5460S/SK106-4 had desirable high yield and quality characteristics and could be used as promising accessions to the rice breeding program in arid regions. In addition to commercial genotypes, improved Japonica rice genotypes could be produced in arid conditions for higher yield and quality, leading to an increase in total production, supporting food security and nutrition.

Impact of climate change on the staple food crops yield in Ethiopia: implications for food security

Climate change is likely to make matters worse in Ethiopia, where the primary sources of food production depend on agriculture, mainly rain-fed agriculture. This study has two folds: first, we estimate the marginal impact of climate variables on the dominant staple food crops (teff, maize, wheat, and sorghum) grown in Ethiopia using feasible generalized least square (FGLS) and autocorrelation and heteroscedasticity consistent standard error for 31 years’ time series data. Second, based on these estimates, we used regional climate models (UQAM _CRCM5 and SMHI_ RCA4) to identify yield sensitivity change in the future. A significant rise in mean monthly temperature and positive change in rainfall were observed from 1988 to 2018. Though an increase in maximum temperature had a favorable effect on all crop yields, a similar increase in minimum temperature was found to have an adverse impact. Since 2000 there has been a considerable increase in total production, but the increasing trends have been due to increases in area cultivated. Towards the end of the twenty-first century, the projection of climate impacts has suggested that with significant increases in temperature and decreases in rainfall result the decline of sorghum yield by 18.1% and wheat yield by 13.2%. However, the yield of teff and maize will be expected to increase by 20.2 and 17.9% respectively. We recommend adopting and expanding locally fitted climate-smart agricultural practices to minimize the long-run climate change impacts on crop production and address the country’s food security problems sustainably.

A novel disinfected Trombe wall for space heating and virus inactivation: Concept and performance investigation

Trombe wall is a simple and mature passive solar building design while its utilization of solar energy is limited to space heating. Aerosol transmission, as a potential transmission pathway of COVID-19, poses a serious threat to the public health especially in a closed indoor environment. The thermal disinfection of virus, which can be easily integrated into solar systems, seems to be a suitable method for controlling bioaerosols. Therefore, a novel disinfected Trombe wall for virus inactivation and space heating is proposed, providing a potential way to fight the current COVID-19 pandemic. After the proposal of the concept, its performance on space heating and virus inactivation was investigated through experimental and simulation methods. The main results were as follows: (1) The average thermal efficiency was 0.457 and the average indoor temperature was 20.7 ℃, 1.9 ℃ higher than the ambient temperature. (2) The maximum single-pass inactivation ratio was 0.893, 0.591 and 0.893 while the total production of clean air was 112.3, 63.8 and 114.7 m3 for SARS-CoV-1, SARS-CoV-2 and MERS-CoV, respectively. (3) The increase of ambient temperature or solar irradiance may enhance the thermal efficiency while the former has little effect on the thermal disinfection process. (4) Extending the height or narrowing the thickness of the duct by 40% may contribute to an increase in total production of clean air by 510 m3 or 681 m3 per unit area during the heating seasons, but the later may cause a larger decrease (about 8%) in the heat gain of indoor air.

Simulation of a GEF5 Gas Turbine Power Plant Using Fog Advanced Cycle and a Systematic Approach to Calculate Critical Relative Humidity

The ambient conditions have a significant effect on the generated power and efficiency of gas turbines [1]. These variations considerably affect power generation, fuel consumption, power plant emissions, and plant incomes. However, cooling the compressor inlet air has been widely used to reduce this deficiency [2]. In this paper, by simulating a specific gas unit in Thermoflow software, the effect of the FOG system on it was studied. Considering the error in determining the capacity of cooling systems based on the average values of dry and wet bulb temperatures, or even considering the worst possible temperature and humidity conditions, it is advisable to use ECDH or Evaporation cooling Degree Hours. Accordingly, by calculating ECDH under at ambient temperatures above 15 °C and changing the conditions of the model, the total production increase of the unit was estimated to be 4.7×106 kWh. In addition, the effect of relative humidity on payback time was examined, which illustrated the critical relative humidity for a gas unit would depend on the price of fuel, the purchase price of electricity, the design parameters of the unit and the expected payback time. For this gas unit, critical relative humidity was monitored based on expected payback time and electricity purchase price. Results showed that for a certain electricity price, at the shorter PBT, the critical RH is lower; therefore, the temperature drop and power enhancement will be greater. In addition, at a certain PBT, as the electricity price increases, the critical RH for the same PBT will be higher.