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Nowadays, non-linear loads are being used in distribution systems increasingly. Despite the good features such as low initial construction cost, high efficiency, and controllability, these loads cause harmonic distortions. In previous studies, passive harmonic filters have been proposed to decrease the produced harmonics, and to do so, various techniques have been suggested. However, the probability of daily load change, possible arrangements of distribution grid taking into consideration the filter design requirements and the impact of temperature change in harmonic filter parameters have been neglected in these studies. Therefore, in the current paper, a comprehensive model based on the probabilistic rearrangement of the distribution grid has been presented for the probabilistic planning of passive harmonic filters. In the proposed method, a two-level probabilistic optimization problem has been introduced with the objective of reducing harmonic distortions, voltage profile improvement, and loss, and investment cost reduction. As a result, the optimum placement of filters, the most optimal number and type of filters, and filter design parameters have been determined. The proposed procedure has been applied to the modified 33-bus IEEE network. The simulation results indicate that neglecting grid rearrangement may lead to a violation of power quality limits during some hours of the day. On the other hand, the combination of various network topologies in planning studies ensures that the total harmonic distortion (THD) level is maintained within the standard range, guaranteeing loss, line density, and filter investment cost reduction. [ABSTRACT FROM AUTHOR]

Introduction The world today is facing the issue of population growth, which will result in food shortages. One way to supply food to this growing population is to facilitate the production of agricultural products to meet the growing demand. Medicinal plants are an important product of the agricultural sector. In Iran, manual harvesting reduces the productivity of these crops, and the use of manual harvesting poses challenges related to available manpower. The costs and time required for manual harvesting are additional obstacles. Given the importance of developing medicinal plants, designing and constructing a mechanized machine for harvesting them could improve the harvesting process. Material and Methods In designing the machine for harvesting medicinal plants in cultivation rows, different scenarios were examined regarding the position of the machine relative to the tractor. The advantages and disadvantages of each scenario were listed separately, and finally, the continuous placement of tractors, harvesters, and trailers was defined. One of the goals of designing this machine is to perform harvesting operations for two row spacing's -80 and 160 cm. To achieve this goal, mechanisms were added to the machine that allow for changing the position of the harvesting head, as well as the cutting height. Moreover, due to the sensitivity of the harvested product to soil contact, the plants should be transferred immediately after cutting. Therefore, a transfer mechanism was designed and built to move the cut products to the trailer. Independent variables, including forward speed at two levels, type of reel in two types, and cutting blade in two types, were considered. Dependent variables also included harvesting efficiency, percentage of damaged plants, and harvesting capacity. Results and Discussion The results of variance analysis for different treatments show that the forward speed, type of reel, and cutting blade type have an effect on harvest efficiency. The difference in harvest efficiency is significant at a 1% probability level. A star cutting blade provides higher efficiency than a 40-teeth cutting blade. The rubber reel prevents plants from falling to the ground by creating a closed space in front of the blade. However, the inner parts of the rods reel are empty, and the plant can fall to the ground. Additionally, the plant may get wrapped around the rods, causing a decrease in harvesting efficiency. Another essential parameter when identifying and evaluating a harvesting machine is crop damage. Some plants get crushed and torn due to the impact on metal components. This situation reduces the quality of the harvested product, leading to a decline in the final product's price. The star-cutting blade causes more leaf rupture. In contrast, the teeth in the 40-teeth blade are continuous, making it unlikely for the leaf to get caught between the two teeth. However, with the star blade, the distance between the two blades is large, allowing the plant to get stuck in between and re-cut. Conclusion Based on tests conducted for eight different positions of the harvester, it was observed that the G test outperformed the other tests with 85.88% harvesting efficiency, a capacity of 344.8 kg h-1, and only 1.34% peppermint leaf damage. Therefore, for harvesting similar peppermint products, we recommend using a combination of a star blade, rubber carousel, and a forward speed of 1.2 meters per second. However, new tests should be conducted on other products like lavender and those with strong stems. [ABSTRACT FROM AUTHOR]

Arc radiation-induced polymer nozzle ablation plays a crucial role in the operation of self-blast circuit breakers. Up to now, there is no study specifically on the spectral distribution of radiated power from a switching arc towards the nozzle surface and its implication to nozzle ablation. Three-dimensional radiation transfer calculation has been performed in this study for arcs burning in the mixture of C 4 F 7 N + C O 2 + PTFE , a gaseous environment that is under significant focus in the development of SF6 free switching technology to aim net-zero by the middle of this century. Results show that photons from infrared to extreme ultraviolet (UV, up to 5 × 1015 Hz) are emitted from the core of high current arcs. However, the high-frequency photons are mostly absorbed within the arc column, especially at the arc edge, and only photons up to 1.7 × 10 15 Hz (far UV, 7 eV) can penetrate the arc edge and cold gas and reach the nozzle surface. The spectral distribution of the radiative energy at different instantaneous currents (15 kA, 28 kA and 60 kA peak) and different locations of the nozzle is presented and compared in detail. The location of the radiation absorption zone at the arc edge and the radiative power reaching the nozzle wall as a function of the instantaneous current is, in particular, purposely considered. [ABSTRACT FROM AUTHOR]

Background: Brucellosis is one of the most important zoonotic diseases caused by Gram-negative bacteria belonging to the genus Brucella. Detection of Brucella species in different countries is of utmost importance. Aims: This study aimed to detect Brucella abortus and Brucella melitensis in domestic ruminant blood samples and their ticks in western Iran. Methods: Sampling was conducted on ruminants from August to September 2020 in four different counties of Kurdistan Province, including Divandareh, Marivan, Baneh, and Sanandaj. Totally, 250 blood samples were collected from 250 small ruminants. There were no ticks on the skin of six (2.4%) ruminants, and 244 ticks were isolated from 244 animals. After genomic DNA extraction from all the collected samples, quantitative polymerase chain reaction (qPCR) was performed to detect IS711 gene. Results: Based on qPCR results, Brucella genus was detected in two blood samples (0.8%) from female sheep and four ticks (1.6%) from male sheep, including three Dermacentor marginatus (1.22%) and one Rhipicephalus turanicus (0.4%). Although B. melitensis was not detected in any tick or blood sample, one tick sample (D. marginatus) was positive for B. abortus. Conclusion: Considering the positivity of ticks for brucellosis in this study, there is a possibility of Brucella transmission from infected ticks to humans and animals through tick bites, nevertheless, in order to identify the Brucella transmission relationship between ticks and animals, serological tests should be used in future studies. [ABSTRACT FROM AUTHOR]