• Title/Summary/Keyword: Alternative conditions

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Spray Characteristics of Dimethyl Ether(DME) Fuel Compared to Various Diesel Fuels

  • Lee, Seang-Wock;Kim, Duk-Sang;Cho, Yong-Seok
    • Journal of ILASS-Korea
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    • v.13 no.2
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    • pp.65-72
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    • 2008
  • It is recognized that alternative fuel such as dimethyl ether (DME) has better combustion polluting characteristics than diesel fuel, even though the cetane number of DME is almost the same as that of diesel. Characteristics of DME spray were observed experimentally under various ambient conditions using a constant volume chamber and a common-rail injection system. N-dodecane and LPG fuel sprays were also observed under same conditions of DME spray. Using spray images from backlight scattering and Mie scattering, characteristics of fuel sprays such as penetration and spray volume were visualized and quantitatively measured. The measurements showed that the penetration of early period decreased remarkably, because evaporation of alternative fuels became prosperous by the influence of flash boiling phenomenon under the condition of the low temperature and pressure compared with n-dodecane. The penetration of DME and LPG spray received the influence of temperature more largely in comparison with low density, because the specific surface area increased by atomizing in high density.

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Comparison of Performance Variation between R-22 and R-410A Refrigeration Systems (운전조건 변화에 따른 R-22 냉동사이클과 R-410A 냉동사이클의 성능변화 비교)

  • 박태준;이민규;정지환;장근선
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.3
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    • pp.166-176
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    • 2003
  • Experiments have been conducted in order to make comparisons of a alternative refrigerant (R-410A) cycle characteristic with an existing refrigerant (R-22) cycle characteristic in terms of cooling capacity and coefficient of performance (COP). The parameters examined in the present work include air flow rate, indoor/outdoor air temperatures, and indoor relative humidity. These two refrigeration cycles share all components except compressor, accumulator, oil separator, and piping connecting them. The measurements were made using an air-enthalpy calorimeter. The experimental results show that the R-410A cycle has many advantages over indoor conditions while the R-22 cycle has better performance over outdoor conditions.

A Comparative Study on the Orgalime's General Conditions for Turnkey Contracts and FIDIC's Silver Book (ORGALIME의 Turnkey 계약용(契約用) 표준약관(標準約款)과 FIDIC의 Silver Book과의 비교연구(比較硏究))

  • Choi, Myung-Kook;Son, Su-Seok
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.23
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    • pp.129-153
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    • 2004
  • What can easily be concluded is that the Orgalime's General Conditions will be preferred by contractors to the Silver Book. However, it is probable that for some projects the Orgalime's General Conditions will not be acceptable to employers without significant amendment, particularly to such matters as design obligations, limitation of liability, force majeure and possibly the extension of time provisions. It is doubtful, however, whether the Orgalime's General Conditions will prove to be an alternative to the Silver Book. For projects for which the Silver Book was intended, the Orgalime's General Conditions will usually be unacceptable to employers and leaders. Notwithstanding this, the Orgalime's General Conditions is a welcome addition to the ever-growing suite of international contracts. And I strongly suggest that we must prepare our "General Conditions for Turnkey Contracts", etc. reflecting our law and practices as soon as possible.

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Comparison of Germination Characteristics and Daily Seed Germination Pattern in 15 New Cultivars of Kentucky Bluegrass under Alternative and Natural Conditions at Room Temperature (자연실온 및 변온환경에서 15종류의 켄터키 블루그래스 신품종의 발아특성 및 일일발아패턴 비교)

  • Kim, Kyoung-Nam
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.5
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    • pp.1-17
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    • 2014
  • Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.) under natural room temperature and to analyze differences between alternative and natural conditions for a practical application. Fifteen cultivars of KB were evaluated in the study. Daily and cumulative germination pattern were measured and analyzed on a daily basis. Differences were observed in germination percentage, germination pattern, days to the first germination and days to 75% germination. Germination percentage was variable with cultivars at the end of study. It was 75.75 to 90.25% under natural condition. There were considerable variations in early germination characteristics and germination pattern among KB cultivars according to germination conditions. The first germination in all entries tested was initiated between 6 and 9 DAS (days after seeding) under ISTA (International Seed Testing Association) condition. But it was observed between 9 and 12 DAS under natural condition, being 3 to 5 days later as compared with ISTA condition. On the first date of a germinating process, the germination rate was 0.25% to 25.00% under ISTA condition, while 0.50% to 13.25% under natural condition. Days to the 75% germination were 15.08 to 28.80 DAS under ISTA condition and 17.78 to 28.75 DAS under natural condition. Midnight II, Excursion and Midnight were the fastest cultivars under ISTA condition, while Odyssey the fastest one under natural condition. Regardless of germination condition, the slowest cultivar was Voyager II, being over 4 weeks to 75% germination percentage. For the most cultivars, days to 75% germination under natural room temperature condition were 1 to 8 days slower than under ISTA condition. From this study information on differences in germination characteristics and pattern among cultivars would be usefully applied for KB establishment such as golf course construction. Prior to on-site seeding, a comprehensive germination test is practically recommended due to a possible decline in germination capability during domestic distribution and storage after import.

Investigation on the Effectiveness of Aqueous Carbonated Lime in Producing an Alternative Cementitious Material

  • Jo, Byung-Wan;Chakraborty, Sumit;Choi, Ji Sun;Jo, Jun Ho
    • International Journal of Concrete Structures and Materials
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    • v.10 no.1
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    • pp.15-28
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    • 2016
  • With the aim to reduce the atmospheric $CO_2$, utilization of the carbonated lime produced from the aqueous carbonation reaction for the synthesis of a cementitious material would be a promising approach. The present investigation deals with the aqueous carbonation of slaked lime, followed by hydrothermal synthesis of a cementitious material utilizing the carbonated lime, silica fume, and hydrated alumina. In this study, the aqueous carbonation reaction was performed under four different conditions. The TGA, FESEM, and XRD analysis of the carbonated product obtained from the four different reaction conditions was performed to evaluate the efficacy of the reaction conditions used for the production of the carbonated lime. Additionally, the performance of the cementitious material was verified analyzing the physical characteristics, mechanical property and setting time. Based on the results, it is demonstrated that the material produced by the hydrothermal method possesses the cementing ability. Additionally, it is revealed that the mortar prepared using the alternative cementitious material yields $33.8{\pm}1.3MPa$ compressive strength. Finally, a plausible reaction scheme has been proposed to explain the overall performances of the aqueous carbonation as well as the hydrothermal synthesis of the cementitious material.

Submerged Culture Conditions for the Production of Alternative Natural Colorants by a New Isolated Penicillium purpurogenum DPUA 1275

  • Santos-Ebinuma, Valeria Carvalho;Teixeira, Maria Francisca Simas;Pessoa, Adalberto Jr.
    • Journal of Microbiology and Biotechnology
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    • v.23 no.6
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    • pp.802-810
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    • 2013
  • This work aims at investigating the production of yellow, orange, and red natural colorants in a submerged culture of Penicillium purpurogenum DPUA 1275. For this purpose, different experimental conditions evaluating the effect of incubation time, type and size of inoculum, and different carbon and nitrogen sources were performed. Furthermore, the growth kinetics were obtained in the conditions of $10^8$ spores/ml and 5 mycelia agar discs during 360 h. These experiments showed that 5 mycelia agar discs and 336 h promoted the highest yellow (3.08 $UA_{400nm}$), orange (1.44 $UA_{470nm}$), and red (2.27 $UA_{490nm}$) colorants production. Moreover, sucrose and yeast extract were the most suitable carbon and nitrogen sources for natural colorants production. Thus, the present study shows a new source of natural colorants, which can be used as an alternative to others available in the market after toxicological studies.

Comparison of Seed Germinating Vigor, Early Germination Characteristics, Germination Speed and Germination Peak Time in New Varieties of The Third Generation of Creeping Bentgrass Under Different Growing Conditions (생육환경에 따른 제3세대 크리핑 벤트그래스 신품종의 종자 발아력, 초기 발아 특성, 발아세 및 발아 피크 기간 비교)

  • Kim, Kyoung-Nam;Jung, Ki-Wan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.5
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    • pp.79-91
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    • 2008
  • Research was initiated to investigate germination characteristics of creeping bentgrass (CB, Agrostis palustris Huds.). Seven varieties of CB were evaluated with different experiments. An alternative environment condition requiring for a CB germination test by International Seed Testing Association (ISTA) was applied in the Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$(ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$(natural conditions). In each experiment, data such as seed germinating vigor, early germination characteristics, germination speed and germination peak time were measured. Significant differences were observed in seed germinating vigor, early germination characteristics, germination speed and germination peak time. Seed germinating vigor was variable with different environments and varieties. It was 61.50 to 98.25% under ISTA conditions and 55.00 to 98.50% under natural conditions. There were considerable variations in early germination characteristics among CB varieties according to different conditions. Early germination characteristics indicated that all varieties were 1 to 4 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 70% and 90%, was much faster with Penn A-1, Penn A-4 and Penncross under ISTA conditions. But it was even faster with L-93 and Penncross when grown under natural conditions. Differences were also observed in germination peak time with varieties and growing conditions. It was 0.57 to 2.86 days under ISTA conditions and 0.74 to 1.74 days under natural conditions. Regardless of the environment conditions, the shortest variety was L-93 and the longest one T-1. Considering germinating vigor, early germination characteristics, germination speed and germination peak time, Penn A-1, Penn A-4 and Penncross were regarded as excellent varieties under ISTA conditions in terms of early establishment characteristics, while L-93, Penn A-1 and Penncross under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for the early germinating vigor, germination speed and germination peak time. Also, a proper variety selection and comprehensive site analysis for the growing environmental conditions should be done before golf course construction.

Comparison of Seed Germinating Vigor, Germination Speed and Germination Peak in Kentucky Bluegrass Cultivars under Different Germination Conditions (발아환경에 따른 켄터키 블루그래스의 종자 발아력, 발아세 및 발아피크 비교)

  • Kim, Kyoung-Nam
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.23-38
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    • 2015
  • The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

Herbs for the Treatment of Insomnia

  • Kim, Chung-Soo;Han, Jin-Yi;Kim, Seung-Hwan;Hong, Jin-Tae;Oh, Ki-Wan
    • Biomolecules & Therapeutics
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    • v.19 no.3
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    • pp.274-281
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    • 2011
  • Pharmacological approaches have been included in conventional medical treatment for insomnia or sleep disorders. However, long-term use of frequently prescribed medications can often lead to habituation, critical withdrawal symptoms and/or side effects. Some individuals with insomnia or trouble sleeping have used complementary and alternative medicine (CAM) therapies to treat their conditions. Recently, CAMs or herbs have been attractive alternative medications to many patients with sleep disorders who may be averse to using conventional drugs. We reviewed the most widely available sleep-promoting herbs commonly used in the western and oriental countries.