• Journal of Ecology and Environment
• /
• 제42권4호
• /
• pp.139-149
• /
• 2018

Background: Ethiopia is among the poorest countries where land degradation caused livelihood problem to its inhabitants. The livelihood of rural communities in Ethiopia is seriously threatened by land degradation. Land is the major natural resource that economic, social, infrastructure, and other human activities are undertaken on. Thus, land resources play an important role in shaping rural livelihoods, and lack of sustainable land management practices leads to land degradation. Thus, this study aimed to analyze interlink between land degradation and livelihood of rural communities in Chilga district, Northwest Ethiopia. It also addresses the factors which influence income diversification for livelihood of households in the study area. Result: The result depicts that the major causes of land degradation are both natural and anthropogenic. Land degradation and livelihood are negatively interlinked with each other. The livelihood of the majority of the population in the study area is dependent on subsistence agriculture both farming and animal husbandry with low diversification. The survey result showed that more than half (69%) of the sample households have farm size of less than 2 ha, nearly one third (31%) have 2.0-2.5 ha, and insignificant number of farmers have more than 2.5 ha. More than 80% of the respondents pointed out that land degradation has impacts both on crop yield and livestock production. Most of the explanatory variables such as gender, age, education level, farmland size, and family size have statistical significant influence (at P < .01 and P < .05 levels) for income diversification of households, while marital status on the other hand is not statistically significant though it has positive relation with income diversification in this study. Conclusions: Our results suggest awareness should be created in the community about the livelihood diversification mechanisms which enabled them to engage in different income-generating activities and comprehensive watershed management should be implemented.

• Journal of Biosystems Engineering
• /
• 제43권1호
• /
• pp.1-13
• /
• 2018

Purpose: The development of compact tractors that can be used in dry fields, greenhouses, and orchards for pest control, weeding, transportation, and harvesting is necessary. The development and performance evaluation of power transmission units are very important when it comes to tractor development. This study evaluates the performance of a driving power transmission unit of a 50 kW multi-purpose narrow tractor. Methods: The performance of the transmission and forward-reverse clutch, which are the main components of the driving power transmission unit of multi-purpose narrow tractors, was evaluated herein. The transmission performance was evaluated in terms of power transmission efficiency, noise, and axle load, while the forward-reverse clutch performance was evaluated in terms of durability. The transmission's power transmission efficiency accounts for the measurement of transmission losses, which occur in the transmission's gear, bearing, and oil seal. The motor's power was input in the transmission's input shaft. The rotational speed and torque were measured in the final output shaft. The noise was measured at each speed level after installing a microphone on the left, right, and upper sides. The axle load test was performed through a continuous equilibrium load test, in which a constant load was continuously applied. The forward-reverse clutch performance was calculated using the engine torque to axle torque ratio with the assembled engine and transmission. Results: The loss of power in the transmission efficiency test of the driving power unit was 6.0-9.7 kW based on all gear steps. This loss of horsepower was equal to 11-18% of the input power (52 kW). The transmission efficiency of the driving power unit was 81.5-89.0%. The noise of the driving power unit was 50-57 dB at 800 rpm, 70-77 dB at 1600 rpm, and 76-83 dB at 2400 rpm. The axle load test verified that the input torque and axle revolutions were constant. The results of the forward-reverse clutch performance test revealed that hydraulic pressure and torque changes were stably maintained when moving forward or backward, and its operation met the hydraulic design standards. Conclusions: When comprehensively examined, these research results were similar to the main driving power transmission systems from USA and Japan in terms of performance. Based on these results, tractor prototypes are expected to be created and supplied to farmhouses after going through sufficient in-situ adaptability tests.

• International Journal of Computer Science & Network Security
• /
• 제21권12호
• /
• pp.349-355
• /
• 2021

The article investigates the conceptual principles of transformation of industrial parks into eco-industrial ones in the conditions of sustainable development. It is substantiated that the concept of sustainable development in the transformation of industrial parks is to grow industry and jobs, modernize production and introduce innovative technologies, resource and energy efficiency, reduce greenhouse gas emissions and waste storage, social protection of local communities and create favorable infrastructure. It is determined that for the transformation of industrial parks, it is necessary to improve regulatory changes, introduce criteria for compliance of industrial parks and the importance of their consideration, ensure park management by the management company and create favorable incentives for industrial entry into industrial symbiosis. It is proved that industrial parks can be an incentive for industrial development and competitiveness of enterprises. The availability of talented human capital, attractive territories, minerals, energy and mineral resources, developed domestic market, agricultural potential, transport networks is becoming an attractive place for investment and development. Industrial parks need investment. Transformation into eco-industrial parks through the implementation of sustainable development goals opens additional opportunities for access to investment funds and contributes to the implementation of growth and prosperity strategies of the country.

• 농업과학연구
• /
• 제45권1호
• /
• pp.114-119
• /
• 2018

This study analyzed the trends of patents for unmanned technology used in agriculture. The target countries for this survey of patent data were Korea, the USA and Japan as well as the countries in Europe. The indices used in this study to analyze the patents were the CPP (Cites Per Patent), PII (Patent Impact Index), and PFS (Patent Family Size). The total effective patents for unmanned technology used in agriculture were 1,080 cases. The number of patents in the USA, Japan, Europe, and Korea were 541, 326, 128 and 85 cases, respectively. Among the total effective patents, the evaluation scores for selected important patents were calculated by applying commonly used weights to each index, and the top 10 patents were selected as important patents. The results showed that all the top ten patents are owned by the United States and that the United States is an advanced country in the field of unmanned technology used in agriculture. The evaluation score of the important patents using the existing method was biased toward the PII index among the three patent evaluation standards, and the effects of the number of claims and the PFS were relatively small. Therefore, a reliable patent analysis in the field of unmanned technology used in agriculture needs to reflect the overall evaluation factors taking into consideration the scope of the evaluation factors.

• 농업과학연구
• /
• 제44권4호
• /
• pp.595-603
• /
• 2017

Crop growth and production cost are greatly influenced by management of environmental factors such as ambient temperature, humidity, and $CO_2$, especially in protected horticulture. Opening and closing of greenhouses is the most important operation for control of these ambient environmental factors, and precise and stable operation requires high performance window motors. In this study, a 400 W precise window motor was constructed, and its performance was evaluated for plastic and glass greenhouses. First, the motor was designed and fabricated by benchmarking of an advanced foreign product. Then, the performance was evaluated through vibration, PCB (Process Control Block), and load tests. Vibration tests resulted in averaged vibration displacement and velocity of the developed motor of 0.002 mm and 0.2267m/s, which were statistically significantly different from those of the target motor. Average vibration acceleration ($0.26m/s^2$) of the developed motor was also significantly different from that ($0.51m/s^2$) of the target motor. PCB tests showed 2 - 4 mm deviation from the target values, and confirmed the operating status and precision of the control. Load tests with a 300 kg load also showed acceptable operating status and durability. Current values were $1.31{\pm}0.06A$ and RPMs were in the range of 2.9 - 3.0. Considering the above results, the developed window motor would be competitive to the target foreign product.

• Applied Biological Chemistry
• /
• 제41권1호
• /
• pp.104-109
• /
• 1998

31과 50종 인도산 식물체 84 시료와 12파 20종 아프리카산 식물체 27 시료의 메탄을 조추출물의 5종 장내세균(Bifidobacterium bifidum, Bifidobacterium longum, Lactobacillus acidophilus, Clostridium perfringens, Escherichia coli)에 대한 생육억제활성을 in vitro 혐기조건하에서 여지확산법으로 검정한 결과 억제활성은 공시세균과 식물체의 종류 및 부위에 따라 달리 나타났다. 인도산 식물체 시료중, Cymbopogon citratus 전부위, Ocimum basilicum 전부위, Madhuca indica 꽃 및 Aegle marmelos 잎 추출물이 Cl. perfringens에 대하여 강한 생육저해활성을 나타낸 반면, O. basilicum 전부위 추출물은 E. coli에 대하여 중간정도의 생육저해활성을 보였다. 그러나, 이들 식물체들은 공시 유산균의 생육에는 영향을 미치지 않았다. 이러한 결과로 부터 이들 열대식물들의 약리학적인 작용을 일부 설명할 수 있을 것으로 사료된다.

• 농업과학연구
• /
• 제41권1호
• /
• pp.59-63
• /
• 2014

Precision farming aims at reduced environmental impacts with increased productivity. Soils are multi-functional media in which air, water and biota occur together and form an essential part of the landscape with a fundamental role in the environment. The requirement for herbicides and fertilizers can vary within a field in response to spatial differences in soil properties. Near infrared (NIR) spectroscopy is widely used today as a nondestructive analytical technique which is capable of determining a number of physio-chemical parameters. The objectives of this study were to develop optimal models to predict chemical properties of paddy soils by visible and NIR reflectance spectra. Total of 60 soil samples were collected in spring from 20 paddy fields within central regions in Korea. Reflectance spectra, moisture contents, pH, total nitrogen (N), organic matter, available phosphate ($P_2O_5$) of soil samples were measured. The reflectance spectra were measured in wavelength ranges of 400-2,500 nm with 2 nm interval. The method of partial least square (PLS) analysis was used to determine the soil properties. The PLS analyses showed good correlation between predicted and measured chemical properties of paddy soils in the wavelength range of 1,800-2,400 nm. Especially, it showed better performance than the previous results which used the entire wavelength range of the spectrophotometer, without considering the optimal wavelength of each soil properties.

• 농업과학연구
• /
• 제21권1호
• /
• pp.28-36
• /
• 1994

식육자원으로서 야생조류인 꿩과 청둥오리고기의 식품안전성에 관하여 검토한 결과는 다음과 같다. 1. 꿩과 청둥오리의 소장, 맹장과 직장에 대한 식중독균 검사에서, Salmonella속균 등 본 실험에서 검사한 3종의 식중독균은 모두 검출되지 않았다. 2. 꿩과 청둥오리의 혈액, 분, 소화기관 및 흉강장기에 대한 기생충검사에서 기생충은 발견되지 않았다. 3. 꿩과 청둥오리의 도체 근육에 대한 디스크 간이법에 의한 항생물질의 잔류검사에서, 모든 시료는 음성반응을 보였다. 4. 꿩과 청둥오리의 근육 및 간에 대한 DDT, BHT 등 7종의 농약 잔류검사에서, 모든 시료는 음성반응을 보였다. 5. 꿩과 청둥오리의 간, 근육 및 혈액에 대한 Cd 등 4종의 독성 중금속 검사에서 그 잔류량은 허용기준 이하였다. 이상의 꿩과 청둥오리에 대한 식품 안전성 검사 결과, 이들의 고기가 인체에 미치는 직접적인 위험도는 매우 낮을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제30권9호
• /
• pp.1335-1342
• /
• 2020

The identification of bacterial pathogens to humans is critical for environmental microbial risk assessment. However, current methods for identifying pathogens in environmental samples are limited in their ability to detect highly diverse bacterial communities and accurately differentiate pathogens from commensal bacteria. In the present study, we suggest an improved approach using a combination of identification results obtained from multiple databases, including the multilocus sequence typing (MLST) database, virulence factor database (VFDB), and pathosystems resource integration center (PATRIC) databases to resolve current challenges. By integrating the identification results from multiple databases, potential bacterial pathogens in metagenomes were identified and classified into eight different groups. Based on the distribution of genes in each group, we proposed an equation to calculate the metagenomic pathogen identification index (MPII) of each metagenome based on the weighted abundance of identified sequences in each database. We found that the accuracy of pathogen identification was improved by using combinations of multiple databases compared to that of individual databases. When the approach was applied to environmental metagenomes, metagenomes associated with activated sludge were estimated with higher MPII than other environments (i.e., drinking water, ocean water, ocean sediment, and freshwater sediment). The calculated MPII values were statistically distinguishable among different environments (p < 0.05). These results demonstrate that the suggested approach allows more for more accurate identification of the pathogens associated with metagenomes.

• Journal of Biosystems Engineering
• /
• 제42권4호
• /
• pp.314-322
• /
• 2017

Purpose: This study was conducted to investigate the hot air drying characteristics of squash slices depending on the drying conditions (input air velocity, input air temperature, and sample thickness). Methods: The developed drying system was equipped with a controllable air blower and electric finned heater, drying chamber, and ventilation fan. Squash (summer squash called Korean zucchini) samples were cut into slices of two different thicknesses (5 and 10 mm). These were then dried at two different input air temperatures (60 and $70^{\circ}C$) and air velocities (5 and 7 m/s). Six well-known drying models were tested to describe the experimental drying data. A non-linear regression analysis was applied to determine model constants and statistical indices such as the coefficient of determination ($R^2$), reduced chi-square (${\chi}^2$), and root mean square error (RMSE). In addition, the effective moisture diffusivity ($D_{eff}$) was estimated based on the curve of ln(MR) versus drying time. Results: The results clearly showed that drying time decreased with an increase in input air temperature. Slice thickness also affected the drying time. Air velocity had a greater influence on drying time at $70^{\circ}C$ than at $60^{\circ}C$ for both thicknesses. All drying models accurately described the drying curve of squash slices regardless of slice thickness and drying conditions; the Modified Henderson and Pabis model had the best performance with the highest R2 and the lowest RMSE values. The effective moisture diffusivity ($D_{eff}$) changes, obtained from Fick's diffusion method, were between $1.67{\times}10^{-10}$ and $7.01{\times}10^{-10}m^2/s$. The moisture diffusivity was increased with an increase in input air temperature, velocity, and thickness. Conclusions: The drying time of squash slices varied depending on input temperature, velocity, and thickness of slices. The further study is necessary to figure out optimal drying condition for squash slices with retaining its original quality.