• 제목/요약/키워드: Energy of Life

검색결과 4,044건 처리시간 0.031초

One-step phyto-mediated fabrication of silver nanoparticles and its anti-microbial properties

  • Velmurugan Palanivel;Sung-Chul Hong;Veera Ravi Arumugam;Sivakumar Subpiramaniyam;Pyong-In Yi;Seong-Ho Jang;Jeong-Min Suh;Eun-Sang Jung;Je-Sung Park
    • Advances in nano research
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    • 제14권4호
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    • pp.391-397
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    • 2023
  • This manuscript describes the one-step eco-friendly green fabrication of silver nanoparticles (AgNPs) through the in-situ bio-reduction of an aqueous solution of silver nitrate using Syzygium aromaticum leaf extract. UV-vis spectroscopy shows a characteristic SPR peak around 442 nm. FTIR spectroscopy showed that the AgNPs were capped with bioactive phyto-molecules. TEM images revealed oval and spherical particles with a mean diameter of ~12.6 nm. XRD analysis revealed crystalline and face-cantered cubic AgNPs. The phytosynthesized AgNPs showed broad-spectrum anti-microbial activity against two foodborne pathogenic bacteria, Listeria monocytogenes and Staphylococcus aureus. The AgNPs showed a prominent ability to inhibit biofilms formed by L. monocytogenes and S. aureus in laboratory conditions through a crystal violet assay. The results suggest that the AgNPs could be a novel nanotool to develop effective antimicrobial and anti-biofilm agents in food preservation.

Power System and Drive-Train for Omni-Directional Autonomous Mobile Robots with Multiple Energy Storage Units

  • Ghaderi, Ahmad;Nassiraei, Amir A.F;Sanada, Atsushi;Ishii, Kazuo;Godler, Ivan
    • Journal of Power Electronics
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    • 제8권4호
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    • pp.291-300
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    • 2008
  • In this paper power system and drive-train for omni-directional autonomous mobile robots with multiple energy storage units are presented. Because in proposed system, which is implemented in soccer robots, the ability of power flow control from of multiple separated energy storage units and speed control for each motor are combined, these robots can be derived by more than one power source. This capability, allow robot to diversify its energy source by employing hybrid power sources. In this research Lithium ion polymer batteries have been used for main and auxiliary energy storage units because of their high power and energy densities. And to protect them against deep discharge, over current and short circuit, a protection circuit was designed. The other parts of our robot power system are DC-DC converters and kicker circuit. The simulation and experimental results show proposed scheme and extracted equations are valid and energy management and speed control can be achieved properly using this method. The filed experiments show robot mobility functions to perform the requested motion is enough and it has a high maneuverability in the field.

국가전력생산 시스템에 대한 전 과정 영향평가 (Life Cycle Assessment for National Electricity Generation Systems)

  • 김태운;김성호;정환삼;하재주;민경란;고순현
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 2004년도 춘계 학술발표회 논문집
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    • pp.353-358
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    • 2004
  • In recent, the trends in national energy Policy are established in the context of the integrated risk estimation for various national electricity generating options. The approach takes account of health, environmental, economic, and social aspects of electricity generation systems. In the present work, nuclear, coal, and LNG sources are chosen because these hold more than 90% of national total electricity generation in a descending order. A life cycle assessment (LCA) methodology is used for comparing environmental impacts of these options during the life cycle such as construction, operation as well as disposal stages. Here, the LCA consists of life cycle inventory analysis, classification/selection process of impact categories, characterization process, and normalization process of each category. LCA can be an useful tool for environmental impact assessment of future national energy options. At the planning stage of future energy Policies, the results of LCA would be taken into consideration. According to data update at the construction and disposal stages, the LCA needs to be conducted iteratively.

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Effects of free feeding time system and energy level to improve the reproductive performance of lactating sows during summer

  • Kim, Kwang Yeol;Choi, Yo Han;Hosseindoust, Abdolreza;Kim, Min Ju;Moturi, Joseph;Kim, Tae Gyun;Song, Chang Hyun;Lee, Jun Hyung;Chae, Byung Jo
    • Journal of Animal Science and Technology
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    • 제62권3호
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    • pp.356-364
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    • 2020
  • The reproductive performance of lactating sows was investigated by using different feeding methods including conventional feeding (CF, 3 times/d) or free feeding (FF), and different dietary energy level including low energy (LE: 3,300) or high energy (HE: 3,400 kcal/kg) during the hot season. A total of twenty-eight crossbred (Yorkshire × Landrace) sows were distributed into four treatments as a 2 × 2 factorial arrangement. Sows in the FF group showed lower body weight and backfat loss (p < 0.05) compared with the CF group. Backfat loss during lactation was lower (p < 0.05) in sows fed HE diet than in that fed LE diet. There were no significant differences in litter survival rate and weaning to estrus interval, but the litter weight at weaning was improved (p < 0.05) in FF and HE sows. Hence, it is concluded that using the free-feeding system or increased dietary energy density leads to improved sow performance during hot ambient temperature.

Life Cycle Analysis and Feasibility of the Use of Waste Cooking Oil as Feedstock for Biodiesel

  • Gahlaut, Aradhana;Kumar, Vasu;Gupta, Dhruv;Kumar, Naveen
    • International journal of advanced smart convergence
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    • 제4권1호
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    • pp.162-178
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    • 2015
  • Petroleum based fossil fuels used to power most processes today are non-renewable fuels. This means that once used, they cannot be reproduced for a very long time. The maximum combustion of fossil fuels occurs in automobiles i.e. the vehicles we drive every day. Thus, there is a requirement to shift from these non-renenewable sources of energy to sources that are renewable and environment friendly. This is causing the need to shift towards more environmentally-sustainable transport fuels, preferably derived from biomass, such as biodiesel blends. These blends can be made from oils that are available in abundance or as waste e.g. waste cooking oil, animal fat, oil from seeds, oil from algae etc. Waste Cooking Oil(WCO) is a waste product and so, converting it into a transportation fuel is considered highly environmentally sustainable. Keeping this in mind, a life cycle assessment (LCA) was performed to evaluate the environmental implications of replacing diesel fuel with WCO biodiesel blends in a regular Diesel engine. This study uses Life Cycle Assessment (LCA) to determine the environmental outcomes of biodiesel from WCO in terms of global warming potential, life cycle energy efficiency (LCEE) and fossil energy ratio (FER) using the life cycle inventory and the openLCA software, version 1.3.4: 2007 - 2013 GreenDelta. This study resulted in the conclusion that the biodiesel production process from WCO in particular is more environmentally sustainable as compared to the preparation of diesel from raw oil, also taking into account the combustion products that are released into the atmosphere as exhaust emissions.

에너지자원의 이산화탄소 배출량과 비용의 상관관계 분석과 전과정평가 (Correlation Analysis on $CO_2$ Emission and Cost of Energy Resources and Life Cycle Assessment)

  • 김희태;김은철;안태규
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.153-153
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    • 2010
  • The world is moving towards a post-carbon society and needs clean and renewable energy for sustainable development. There are many methodological approaches which are helping this shift based on analyzed data about energy resources and which focus on limited types of energy including liquid fossil, solid fossil, gaseous fossil, and biomass (e.g. IPCC Guidelines, ISO 14064-1, WRI Protocol, etc.). We should also consider environmental impact (e.g. greenhouse gas emissions, water use, etc.) and the economic cost of the renewable energy to make a better decision. Recently, researchers have addressed the environmental impact of new technologies which include photovoltaics, wind turbines, hydroelectric power, and biofuel. In this work, we analyze the environmental impact with a carbon emission factor to present a correlation between $CO_2$ emission and the cost of energy resources standardized by the energy output. In addition, we reviewed Life Cycle Assessment (LCA) as another methodology. Researchers who are studying energy systems have ignored the impacts of entire energy systems, e.g. the extraction and processing of fossil fuels. In power sector, the assessment should include extraction, processing, and transportation of fuels, building of power plants, production of electricity, and waste disposal. Therefore LCA could be more suitable tool for energy cost and environmental impact estimation.

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평균응력을 동반하는 2.2Ni-lCr-0.5Mo강의 피로수명과 변형률에너지 밀도와의 상관관계 (Correlation Between Fatigue Life of 2.2Ni-0.1Cr-0.5Mo Steel Accompanying Mean Stresses with Cyclic Strain Energy Density)

  • 고승기;하정수
    • 대한기계학회논문집A
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    • 제27권1호
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    • pp.167-174
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    • 2003
  • Fatigue damage of 2.2Ni-1Cr-0.5Mo steel used fir high strength pressure tubes and vessels was evaluated using uniaxial specimens subjected to strain-controlled fatigue loading. Based on the fatigue test results from different strain ratios of -2. -i 0, 0.5, 0.75, the fatigue damage of the steel was represented by using a cyclic strain energy density. Mean stress relaxation depended on the magnitude of the applied strain amplitude. The high pressure vessel steel exhibited the cyclic softening behavior. Total strain energy density consisting of the plastic strain energy density and the elastic tensile strain energy density described fairly well the fatigue life of the steel, taking the mean stress effects into account. Compared to other fatigue damage parameters, fatigue life prediction by the cyclic strain energy density showed a good correlation with the experimental fatigue lift within a factor of 3.

사상체질에 따른 식습관 행태와 건강관련 삶의 질과의 연관성 (Association of Breakfast, Eating Frequency, and Energy Intake with Health-related Quality of Life According to Sasang Constitution: in Korean General Population)

  • 정경식;이시우;김지은;백영화
    • 사상체질의학회지
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    • 제33권2호
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    • pp.37-46
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    • 2021
  • Background According to the Sasang constitutional medicine, eating habits according to the characteristics of Sasang Constitution (SC) types affect management of chronic diseases and health conditions. The aim of this study is to identify the association between eating habits, such as breakfast, eating frequency, and energy intake, according to SC, and quality of life. Method This study is a cross-sectional study of people aged 33 to 55 years, sampled by stratification based on population distribution. The SC types were classified into Taeeumin (TE), Soeumin (SE), and Soyangin (SY) using a structured questionnaire (KS-15). Items examined regarding eating habits were whether the subjects had breakfast; the frequency of eating such as breakfast, lunch, dinner, and after-dinner snacks; and energy intake surveyed using a food frequency questionnaire. As for quality of life, SF-12, which is widely used worldwide to assess health conditions, was utilized. A regression analysis was conducted on the relations between eating habits according to SC and quality of life. Results The SC distribution of the 3,895 subjects was 47% for TE, 22% for SE, and 31% for SY. The scores indicating quality of life differed for TE and SY depending on whether they ate breakfast and eating frequency groups, and those of SE varied depending on levels of energy intake. A regression analysis having adjusted all covariates demonstrated for TE a positive relation between the eating frequency of three times per day or more (compared to 1.5 to 3 meals per day) and quality of life (B=1.365, p<0.001). For SE, there was a negative association between low energy intake (compared to adequate energy intake) and quality of life (B=-1.642, p=0.004). Meanwhile, no relation was found between eating habits and quality of life for SY. Conclusion This study identified the association between eating habits according to SC types and quality of life. For TE, it was found to be important to eat evenly dispersed adequate amounts as opposed to overeating or binging at once. For SE, adequate energy intake affected good quality of life. This study suggests that eating habits based on SC improve quality of life, and health management customized for each constitution should be performed in the future through proper eating habits.