• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.25-36
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• 2020

Area exclosure is a widely practiced intervention of restoring degraded lands though its impact in sequestering terrestrial and soil carbon is scanty. The study was initiated to investigate the effect of exclosure of different ages on carbon sequestration potential of restoring degraded dryland ecosystems in eastern Tigray, northern Ethiopia. Twelve plots each divided into three layers were randomly selected from 5, 10 and 15 years old exclosures and paired adjacent open grazing land. Tree and shrub biomasses were determined using destructive sampling while herb layer biomass was determined using total harvest. The average total biomass obtained were 13.6, 24.8, 27.1, and 55.5 Mg ha^-1 for open grazing, 5 years, 10 years, and 15 years exclosures respectively. The carbon content of plant species ranged between 48 to 53 percent of a dry biomass. The total carbon stored in the 5 years, 10 years and 15 years age exclosures were 39 Mg C ha^-1, 46.3 Mg C ha^-1, and 64.6 Mg C ha^-1 respectively while in the open grazing land the value was 24.7 Mg C ha^-1. Carbon stock is age dependent and increases with age. The difference in total carbon content between exclosures and open grazing land varied between 14.3-40 Mg C ha^-1. Although it is difficult to extrapolate this result for a longer future, the average annual carbon being sequestered in the oldest exclosure was about 2.7 Mg C ha^-1 yr^-1. In view of improving degraded area and sequestering carbon, area exclosures are promising options.

• KIEAE Journal
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• v.13 no.5
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• pp.43-50
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• 2013

Recent researches on plant factory system deal with the convergence of lighting technology, agricultural technology inclusive to the high-tech industries worldwide in order to respond to the decreasing crop harvest due to global warming and abnormal weather phenomena. However, the fundamental performance standard is not currently being introduced in the case of plants factory and its commercialization is not activated because of high initial investment and operating cost. Large portion of the initial investment and operating cost of a plant factory is ascribed to artificial light sources and thermal control facilities, therefore, innovation should be provided in order to improve the economics of the plant factory. As an alternative, new plant factory could harness solar thermal and geothermal systems for heating, cooling and ventilation. In this study, a natural light dependent multi-layer plant factory's thermal environment was analyzed with two-dimensional numerical methods to elicit efficient operation conditions for optimized internal physical environment. Depending on the supply air temperature and airflow rate introduced in the facility, the temperature changes around the crops was interpreted. Since the air supplied into the plant factory does not stay long enough, the ambient temperature predicted around the plating trays was not significantly different from that of the supplied air. However, the changes of airflow rate and air flow pattern could cause difference to the temperature around the planting trays. Increasing the amount of time of air staying around the planting trays could improve energy performance in case the thermal environment of a natural light based multi-layer plant factory is considered.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.463-472
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• 2003

Cassava (Manihot esculenta, Crantz), an annual tropical tuber crop, was nutritionally evaluated as a foliage for ruminants, especially dairy cattle. Cultivation of cassava biomass to produce hay is based on a first harvest of the foliage at three months after planting, followed every two months thereafter until one year. Inter-cropping of leguminous fodder as food-feed between rows of cassava, such as Leucaena leucocephala or cowpea (Vigna unculata), enriches soil fertility and provides additional fodder. Cassava hay contained 20 to 25% crude protein in the dry matter with good profile of amino acids. Feeding trials with cattle revealed high levels of DM intake (3.2% of BW) and high DM digestibility (71%). The hay contains tannin-protein complexes which could act as rumen by - pass protein for digestion in the small intestine. As cassava hay contains condensed tannins, it could have subsequent impact on changing rumen ecology particularly changing rumen microbes population. Therefore, supplementation with cassava hay at 1-2 kg/hd/d to dairy cattle could markedly reduce concentrate requirements, and increase milk yield and composition. Moreover, cassava hay supplementation in dairy cattle could increase milk thiocyanate which could possibly enhance milk quality and milk storage, especially in small holder-dairy farming. Condensed tannins contained in cassava hay have also been shown to potentially reduce gastrointestinal nematodes in ruminants and therefore could act as an anthelmintic agent. Cassava hay is therefore an excellent multi-nutrient source for animals, especially for dairy cattle during the long dry season, and has the potential to increase the productivity and profitability of sustainable livestock production systems in the tropics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.273-278
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• 2002

An efficient low-input system (LIS) for fertiliser use in rice cultivation is necessary to reduce fossil energy use and pollution. Japanese people like Japonica rice, especially cv. Koshihikari. However, it has very low lodging resistance in Japanese weather condition. Our objective was to develop a LIS with the minimum sacrifice of grain yield in rice. Koshihikari was grown using conventional fertilization as a control (CON) with 4 g N $m^{-2}$., 8g $P_2$ $O_{5}$ $m^{-2}$ and 8 g $K_2$O $m^{-2}$ as a basal fertilizer dressing. It was compared with a low fertilizer treatment (LF) with only 4 g $P_2$ $O_{5}$ $m^{-2}$ as a basal dressing in the first year and no basal phosphorus fertilizer in the second year. Chopped rice straw was incorporated into the soil before the cropping season in both years. Fertilizer of 4 g N $m^{-2}$ was top-dressed at 15 days before heading in CON plots and 30 days before heading in LF plots in both years. Lodging was significantly less in LF than in CON plots, however, no rice straw effect was found in low fertilized condition. Grain yields in LF plots were reduced by 15-16% below those of CON plots. Lower yields in LF plots were associated with a reduced number of spikelets per unit area. However, big spikelet size was acquired in LF by 10 days earlier N top dressing than CON plots. A close relationship was found between spikelet numbers and N content of the plant at heading, and between grain yield or shoot dry weight and N content of the plant at maturity. Regardless of the fertilizer application methods, N use efficiency for the number of spikelets, final total dry matter and grain yield was essentially identical among fertilizer treatments. The reduced growth and yield in the LF plots resulted from low absorption of nitrogen. Conclusively, LIS can drastically reduce chemical fertilizer use and facilitate harvest operations by reducing lodging with some yield reduction..

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.1022-1028
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• 2005

The objectives of this study were to evaluate and compare the environmental load of two different concentrate feed supply systems to the Japanese domestic livestock industry using the Life-cycle Assessment (LCA) method. The current system was defined as that requiring 11.469 million tons of corn imported from the US by sea transport and supplied as concentrate feed to the Japanese domestic livestock industry. The new system proposed by Kaku et al. in 2004 was defined as where 802,830 tons of US imported corn would not be planted in US and would be replaced by barley planted in 278 thousand ha of Japanese domestic land left fallow for the past year. In this case, 909,000 tons of domestic harvest barley would have been supplied as concentrate feed to the Japanese domestic livestock industry in 2000. The activities taken into account within the two system boundaries were three stages: concentrate feed production, feed transportation and gas emission from the soil by chemical fertilizer. Finished compost was regarded as organic fertilizer and was put instead of chemical fertilizers within the system boundary. Adoption of this new concentrate feed supply system by the Japanese domestic livestock industry could reduce 78,462 tons $CO_2$-equivalents of global warming potential, 347 tons $SO_2$-equivalents of acidification potential, 54 tons $PO_4$-equivalents of eutrophication potential and 0.842 million GJ as energy consumption below 2,000 levels. This LCA study comparing two Japanese domestic livestock concentrate feed supply systems showed that the stage of feed transport contributed most to global warming and the stage of emission from the soil contributed most to acidification and eutrophication. The Japanese domestic livestock industry could participate in emissions trading with $CO_2$-equivalents reduced by shifting from some imported US corn as a concentrate feed to domestic barley planted in land left fallow. In that case the Japanese government could launch emissions trading in accordance with Kyoto Protocol in the future.

• Korean Journal of Medicinal Crop Science
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• v.20 no.2
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• pp.136-139
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• 2012

This study is part of research to develop the technology for managing major medicinal crops after harvest. We studied the optimal germination conditions of $Cynanchum$ $wilfordii$ (Maxim.) Hemsl. The mean germination time (MGT) of $C.$ $wilfordii$ seeds was higher after soaking for 4 days after storage at $5^{\circ}C$ for 8 weeks, than with germination at $25^{\circ}C$ (3 days). However, the germinative energy (GE) decreased as the number of days soaking increased. The greatest germination rate ($83.3{\pm}8.8%$) was at $25^{\circ}C$ with no soaking of seeds stored at $-20^{\circ}C$ for 8 weeks. Based on these results, we characterized the germination conditions of a major medicinal crop.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.461-465
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• 2013

This study was investigated to evaluate germination rate of Astragalus membranaceus B. in Korea as affected by storage temperature, germination temperature and storage period of seed. The highest germination rate was obtained from condition of $25^{\circ}C$ in germination temperature. Seeds were stored at $-20^{\circ}C$ and $5^{\circ}C$ for 8 weeks has showed higher germination rate than one at room temperatures. The germination rates showed significantly difference by harvested year of 2010, 2011 and 2012. The seed of A. membranaceus in harvested year of 2011 and 2012 had germinated well. On the other hand, seeds in harvested year of 2010 were not nearly germinated. Consequently, the longer storage period after seed harvest lower germination rate and seed vigor as well.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.516-521
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• 2022

We investigated the microstructure, crystal structure, dielectric, and elecromechanical strain properties of lead-free BaTiO₃ (BT)-modified (Bi_1/2Na_1/2)TiO₃-SrTiO₃ (BNT-ST) piezoelectric ceramics. Samples were prepared by a conventional ceramic processing route. Temperature dependent dielectric properties confirmed that a phase transition from a nonergodic relaxor to an ergodic relaxor was induced when the BT concentration reached 1.5 mol%, interestingly, where the average grain size reached a maximum value of 4.5 ㎛. At the same time, enhanced electromechanical strain (S_max/E_max = 600 pm/V) was obtained. It is suggested that the induced ferroelectric-relaxor phase transition by the BT modification is responsible for the enhancement of electromechanical strain in 1.5 mol% BT-modified BNT-ST ceramics.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.3
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• pp.350-355
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• 1986

Sixteen Korean leading barley varieties were tested on the sixtieth day after harvest, in order to investigate differences for germinative traits related, and on the eightieth day to test optimum water level for germination test. The germinative energy(GE) and capacity(GC) in the 4.5cc water level were the highest individually. Varietal variations among GE, GC, promptness index(PI) and water sensitivity(WS) were highly significant in storage conditions and water levels. Correlation coefficient estimated were positive among GE, GC, PI, but negative between these traits and WS. Also the varietal difference of WS gets higher with the following order of malting barley<naked barley<covered barley. Heritabilities of broad sense for GE, GC, PI and WS were high, therefore, these traits could be considered in malting barley breeding.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.2
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• pp.141-147
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• 2024

The measurement of strain under an electric field has been widely employed to comprehend the fundamental principles of electro-mechanical responses in ferroelectric, piezoelectric, and electrostrictive materials. In particular, understanding the strain properties of piezoelectric materials in response to electrical stimulation is crucial for researching and developing components such as piezoelectric actuators, acoustic devices, and ultrasonic generators. This tutorial paper introduces the components and operational principles of the linear variable differential transducer (LVDT), a widely used displacement measurement device in various industries. Additionally, we present the configuration of an experimental setup using LVDT to measure the strain characteristics of ferroelectric, piezoelectric, or electrostrictive materials under the application of an electric field. This paper includes simple measurement results and analyses obtained through the LVDT experimental setup, providing valuable information on research methods for the electro-mechanical interactions of various materials.