This paper addresses the enhancement of long-endurance solar-powered aircraft through the integration of a rechargeable battery and Maximum Power Point Tracking (MPPT) controller. Traditional long-endurance aircraft often rely on non-renewable energy sourcessuch as batteries orjetfuel, contributing to carbon emissions. The proposed system aims to mitigate these environmental impacts by harnessing solar energy and efficiently managing its storage and utilization. The MPPT controller optimizes the power output of photovoltaic cells, enabling simultaneous charging and discharging of the battery for propulsion and servo control. A prototype is presented to illustrate the practical implementation and functionality of the proposed design, marking a promising step towards more sustainable and enduring solar-powered flight.
Penicillium oxalicum (PENOX) has shown the potential as a biocontrol agent(5CA) for control of a weed, clover(Trifolium repens L.) in grass plots. The bioherbicidal activity may be due to germinative and growth capacities and substrate availability of the agent over a range of environmental factors. The influences of different water activities($0.94{\sim}0.995\;a_w$) and temperatures($18{\sim}30^{\circ}C$) on mycelial growth, conidial germination, sporulation oil 2% MEA(malt extract agar) adjusted to different water activities with glycerol, and carbon source utilization using BIOLOG GN MicroPlate were determined in vitro. Decreases in $a_w$ on MEA caused a reduction in mycelial growth and conidial germination depending on temperature. The mycelial growth of PENOX was greatest at $30^{\circ}C/0.995\;a_w$. At some lowered water activity($0.97\;a_w$), the growth was similar between 25 and $30^{\circ}C$, and considerably decreased at lowered temperature($20^{\circ}C$). The germination rate was also greatest at $30^{\circ}C/0.995\;a_w$. Lag phase times for PENOX at $18^{\circ}C$ on MEA were >6hrs at tile whole $a_w$ level tested, and at 18 and $25^{\circ}C$ they were >18hrs and >12hrs at $0.94\;a_w$, respectively. However, its sporulation was some better at $0.97\;a_w$ than $0.995\;a_w$ or $0.94\;a_w$, and better at $20^{\circ}C$ than $30^{\circ}C$. In contrast, the number of carbon sources(niche size) utilized by PENOX varied with $a_w$ and temperature. Under some water stress condition($0.95\;a_w$), the agent utilized smaller number of carbon sources than $0.995\;a_w$ depending on temperature. The niche size at 0.995 and $0.95\;a_w$ were highest at $25^{\circ}C$, and showed 86 and 65, respectively. At $30^{\circ}C$, the niche size at 0.995 and $0.95\;a_w$ showed 84 and 50, respectively. There was no carbon source utilized by PENOX at $0.90\;a_w$ regardless of temperature. These information of tile fungal ecophysiology will be useful for the effective development of BCA.
In order to obtain the basic informations on the production of single cell protein from ethanol, 145 yeast strains utilizing ethanol as a sole carbon source were isolated from 32 soil samples in Korea. A yeast strain showing the highest cell yield among the isolated strains was selected and identified. The optimum culture condition, utilization of other carbon sources and the cultural characteristics for the selected yeast, and the chemical analysis of the yeast cell composition, and utilization of ethanol by the selected yeast were investigated. All the culture was carried out in the shaking flasks. The results obtained were as follows: 1. The selected yeast strain was identified as Debaryomyces nicotianae-SNU 72. 2. The optimum composition of the medium for the selected yeast is : Ethanol 40 ml, Urea 0.5 g, Potassium phosphate (dibasic) 0.5 g, Ammoium phosphate (monobasic) 0.15 g, Magnesium sulfate 0.05 g, Calcium chloride 0.01g, Yeast extract 0.005 g, Tap water 1000 ml. 3. The optimum pH was 5.0-5.5, the optimum temperature $30-33^{\circ}C$ and the aerobic state was unimportant. 4. Utilization of methanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-amyl alcohol and acetic acid by the selected yeast was very weak. So substitution of the subtrate was thought to be impossible. 5. Studies on the propagation of the yeast cells showed that the lag phase of the yeast cells lasted 16 hours, and the logarithmic growth phase extended 16 to 28 hours. The specific growth rate was about $0.19\;hr^{-1}$ and the doubling time was 3.6 hours during the logarithmic growth phase. 6. As the result of the chemical analysis of the dry yeast cells, the content rate of the crude protein was 55.19 %, the content of others was similar to the average content of the yeast component. 7. After 34 hours cultivation, under the optimum culture condition investigated, the dry cell yield against the amount of the added ethanol was 53.4 % (W/V%), the dry cell yield against the amount of the utilized ethanol was 73.6 % (W/V%), the evaporation rate of ethanol was about 19.1 %.
Jin Bong-Soo;Doh Chil-Hoon;Moon Seong-In;Yun Mun-Soo;Jeong Jae-Kook;Nam Hyo-Duk;Park Hei-Gu
Journal of the Korean Electrochemical Society
/
v.7
no.3
/
pp.143-147
/
2004
An investigation upon the characterization of MCMB anodes with different vapor grown carbon fiber (VGCF) content for application in lithium polymer battery(LPB) was carried out. When VGCF material was used as conducting agent with MCMB active material, the impedance and the initial coulombic efficiency of test cells were found to decrease with the increasing amount of VGCF. On the other hand, as a function of added VGCF the discharge capacity and the utilization linearly with increased. Impedance of test cell with MCMB anode containing $6wt\%$ VGCF exhibited the lowest value whereas the impedance of $8wt\%$ VUF contained anode was similar to that of MCMB anode without VGCF. Interestingly, $6wt\%$ VUF contained anode showed the best battery characteristics. Internal resistance and rate capacity of the cell were. respectively, $0.918{\Omega}\;at\;25C\;and\;93\%$ at 2C. Generally, rate capability and the cycleability of MCMB based test cells with $4\~6wt\%$ VGCF content exhibited better results than the other cells. In the case of $6wt\%$ VGCF containing anode, the discharge capacity of the cell faded slowly with an ultimate charge-discharge cycling capacity of 178mAh/g at the 100th cycle. Thereafter, the discharge capacity faded negligibly and the utilization of the cell at the 100th cycle was more than $90\%$. The effect of addition of VGCF is discussed in detail.
A repeated $4{\times}4$ Latin square design was conducted with eight ileal cannulated castrates to examine the effect of source of starch and fiber on nutrient balance and energy metabolism. Pigs were fed on one of the four experimental diets: Control diet (C) mainly based on cooked rice; and diets P, S and W with the inclusion of either raw potato starch, sugar beet pulp or wheat bran supplementation, respectively. With the exception of an increased (p<0.05) energy loss from methane production with diet S observed, no significant differences (p>0.05) in the ratio of metabolizable energy (ME)/digestible energy, the utilization of ME for fat deposition and for protein deposition, energy loss as hydrogen and urinary energy were found between diets. The efficiency of utilization of ME for maintenance was lower (p<0.05) with diets P and S than with diet C. The inclusion of fiber sources (sugar beet pulp or wheat bran) or potato starch reduced the maintenance energy requirement. The fecal energy excretion was increased (p<0.05) with either sugar beet pulp or wheat bran supplementation, while it was unaffected (p>0.05) by addition of potato starch. In comparison with diets C and P, a lowered ileal or fecal digestibility of energy with diets S and W was observed (p<0.05). Feeding sugar beet pulp caused increased (p<0.05) daily production of methane and carbon dioxide and consequently increased energy losses from methane and carbon dioxide production, while it did not influence the daily hydrogen production (p>0.05). An increased (p<0.05) proportion of NSP excreted in feces was seen by the supplementation of wheat bran. Higher NSP intake caused an increased daily amount of NSP in the ileum, but the ileal NSP proportion as a percentage of NSP intake was unaffected by diets. Feeding potato starch resulted in increased daily amount of starch measured in the ileum and the proportion of ileal starch as a percentage of starch intake, while no significant influence on fecal starch was found. Higher (p<0.05) daily amount of fecal starch and the proportion of fecal starch as a percentage of starch intake were found with fiber sources supplementation compared with diets C and P. By increasing the dietary NSP content the fecal amount of starch increased (p<0.01).
Microbial Fe(III) reduction is an important factor for biogeochemical cycle in anaerobic environments, especially sediment of freshwater such as lakes, ponds and rivers. In addition, the Fe(III) reduction serves as a model for potential mechanisms for the oxidation of organic compounds and the reduction of toxic heavy metals, such as chrome or uranium. Shewanella putrefaciens DK-1 was a gram-negative, facultative anaerobic Fe(III) reducer and used ferric ion as a terminal electron acceptor for the oxidation of organic compounds to $CO_{2}$ or other oxidized metabolites. The ability of reducing activity and utilization of various electron acceptors and donors for S. putrefaciens DK-1 were investigated. S. putrefaciens DK-1 was capable of using a wide variety of electron acceptor, including $NO_{3}^{-}$, Fe(III), AQDS, and Mn(IV). However, its ability to utilize electron donors was limited. Lactate and formate were used as electron donors but acetate and toluene were not used. Fe(III) reduction of S. putrefaciens DK-l was inhibited by the presence of either $NO_{3}^{-}$ or $NO_{2}^{-}$. Further S. putrefaciens DK-1 used humic acid as an electron acceptor and humic acid was re-oxidized by nitrate. Environmental samples showing the Fe(III)-reducing activity were used to investigate effects of the limiting factors such as carbon, nitrogen and phosphorus on the Fe(III) reducing bacteria. The highest Fe (III) reducing activity was measured, when lactate as a carbon source and S. putrefaciens DK-1 as an Fe(III) reducer added in untreated sediment samples of Cheon-ho and Dae-ho reservoirs.
This study of adsorption and column percolation was conducted to examine the utilization of natural zeolite for the removal of heavy metals from waste water to compare with that of absorption activated carbon. The adsorption of heavy metals by natural zeolite was conformed to the Freundlich isotherm (1/n values: $0.12{\sim}0.45$, K values: $18.77{\sim}59.48$) and natural zeolite was turned out to be an effective adsorbent of heavy metals. At the same particle size and percolation velocity, zeolite adsorbed a greater amount of heavy metals was adsorbed on natural zeolite than activated carbon. The smaller the particle size, the more heavy metals that were adsorbed. It was postulated that the most effective size as an adsorbent of heavy metals from waste water ranged from 0.5 to 2.0mm. The slower the percolation velocity that of the heavy metal solution in column, the more heavy metals were adsorbed. Natural zeolite in a single solution adsorbed more heavy metals than that in mixed solution, and the order of the adsorption amount on natural zeolite was Cu>Zn>Cd.
Journal of the Korean Society for Marine Environment & Energy
/
v.8
no.4
/
pp.203-212
/
2005
Anthropogenic emissions of greenhouse gases, particularly carbon dioxide($CO_2$) which arises mainly as wastes from the fossil fuel burning processes, are causing global warming. The effects of global warming become increasingly felt all over the world including sea level rise and extreme weather. The more direct consequences of the elevated atmospheric $CO_2$ on the ocean is the acidification of the surface ocean which brings a far reaching adverse impact on the life at sea and probably on the whole ecosystem of the planet. Improvement in energy efficiency and use of alternative energy sources are being made to reduce $CO_2$ emissions. However, a rapid transition to alternatives seems unachievable within a few decades due to the constraints on the associated technology and socio-economic factors in the world, since fossil fuels make up approximately 85% of the world's commercial energy demands. It has now been recognized that capture and geological sequestration of $CO_2$ could significantly reduce its emissions from fossil fuel utilization and therefore provides the means to rapidly achieve large reductions in $CO_2$ emissions(excerpts from London Convention, LC/SG 28, 2005). In Korea, well-developed sedimentary basins are spread over the vast continental shelf and slope regions, whereas, the land is densely populated and limited in area. Consequently, the offshore area is preferred to the land for the sites for geological sequestration. The utilization of the offshore area, however, may be subject to international agreements including London Convention. In this paper, the recent trends in technologies and regulations for $CO_2$ capture and geological sequestration are described to encourage its applications in Korea.
The effects of a high-fat diet and fasting on resting energy expenditure and energy substrate utilization were examined using the method of measuring whole body energy metabolism and oxygen uptake. Eight 4-week old male Sprague-Dawley rats were used for the high-fat diet experiment. Energy metabolism was measured using acrylic metabolic chambers over 24 hours. After 1-week of preliminary feeding, 4 rats were fed a chow diet, whereas the remaining 4 rats were fed a high-fat diet (HF) ad libitum, which contained 40% (w/w, calorie base 60%) more fat than that in the chow diet. The flow rate to measure energy metabolism inside the chamber was controlled at a mean of 3.5 L/min, and five chambers were subjected to measurement. One of the five chambers was used to correct errors by measuring the atmosphere. As a result of 5 weeks of control diet and high-fat diet feeding, body weight of the high-fat diet group tended to increase more than that in the control diet fed group, but the difference was not significant. Oxygen uptake and carbon dioxide production changed as time went on over the 24 hr. The respiratory exchange ratio also changed during the 24 hr, and the difference between the groups was significant. The control group showed significantly more carbohydrate oxidation than that of the high-fat diet fed group. A fasting experiment was conducted using six 7-week old Sprague-Dawley male rats. Energy metabolism measurements were performed using the same method as that used in the high-fat diet experiment; resting metabolism was measured prior to fasting, and a fasting condition began from 9:00 am the next day for 3 days to calculate energy metabolism. Both body weight and 24-hour oxygen uptake decreased significantly as a result of 3-day fasting. Total oxygen uptake in the first day decreased, and declined significantly on day 3 of fasting. Total 24-hour carbon dioxide production decreased significantly over the 3 days. The mean 24-hour respiratory exchange ratio decreased significantly. Additionally, energy expenditure during the dark period (20:00-08:00), which is the active period for rats, decreased significantly with fasting, whereas energy expenditure during the light period (08:00-20:00) did not increase by fasting.
This study aimed to develop a soft fabric-based elbow-bending angle sensor that can replace conventional hard-type inertial sensors and a system for estimating bending angles using it. To enhance comfort during exercise, this study treated four fabrics (Bergamo, E-band, span cushion, and polyester) by single-walled carbon nanotube dip coating to create conductive textiles. Subsequently, one fabric was selected based on performance evaluations, and an elbow flexion angle sensor was fabricated. Gauge factor, hysteresis, and sensing range were employed as performance evaluation metrics. The data obtained using the fabricated sensor showed different trends in sensor values for the changes in the angle during bending and extending movements. Because of this divergence, the two movements were separated, and this constituted the one-step process. In the two-step process, multilayer perceptron (MLP) was employed to handle the complex nonlinear relationships and achieve high data accuracy. Based on the results of this study, we anticipate effective utilization in various smart wearable and healthcare domains. Consequently, a soft- fabric bending angle sensor was developed, and using MLP, nonlinear relationships can be addressed, enabling angle estimation. Based on the results of this study, we anticipate the effective utilization of the developed system in smart wearables and healthcare.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.