• Title/Summary/Keyword: Maxima

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Jet Impingement Heat Transfer on a Cylindrical Pedestal Encountered in Chip Cooling (충돌제트를 이용한 Pedestal 형상의 칩 냉각연구)

  • Lee, Dae-Hee;Lee, Joon-Sik;Chung, Young-Suk;Chung, Seung-Hoon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.1
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    • pp.1-8
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    • 2003
  • The heat transfer and flow measurements on a cylindrical pedestal mounted on a flat surface with a turbulent impinging jet were made. The experiments were made for the jet Reynolds number of Re = 23,000, the dimensionless nozzle-to-surface distance of L/d = 2~10, the dimensionless pedestal height of H/D = 0~1.5. Measurements of the surface temperature and the Nusselt number distributions on the plate surface were made using liquid crystal and shroud-transient technique. Flow measurements involve smoke flow visualization and the wall pressure coefficient. The results show that the wall pressure coefficient sharply decreases along the upper surface of the pedestal. However, the pressure increases when the fluid escapes from the pedestal and then collides on the plate surface. The secondary maxima in the Nusselt numbers occur in the region of 1.0 $\leq$ r/d $\leq$ 1.9. Their values for the case of H/D = 0.5 are maximum 80% higher than those for other cases. The formation of the secondary maxima may be attributed to the reattachment of flow on the plate surface which was separated at the edge of the pedestal.

Occurrence and identification of Emeria species in broiler rearing under traditional system

  • Shamim, Asim;Hassan, Murtaz ul;Yousaf, Arfan;Iqbal, Muhammad Farooq;Zafar, Muhammad Arif;Siddique, Rao Muhammad;Abubakar, Muhammad
    • Journal of Animal Science and Technology
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    • v.57 no.12
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    • pp.41.1-41.4
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    • 2015
  • Background: The present study was intended to determine the prevalence and identification of species involved causing coccidiosis in broilers rearing under traditional farming system in Mirpur, Azad Kashmir, Pakistan. For the current study, a convenient sampling technique was carried out. A total of 7814 broilers (aged 1 to 6 weeks) were submitted to the Disease Diagnostic Laboratory of Livestock and Animal husbandry Department Mirpur, Azad Kashmir. Results: From the total screened, 750 were found positive for coccidiosis representing an overall prevalence of 9.59 %. Age-wise highest prevalence (10.88 %) recorded in the middle age birds (0 to 3 week old) were found more susceptible to infection than those aged above 3 weeks. Higher prevalence (12.49 %) of coccidiosis in broilers was observed in spring as compared with 6.60 % in summer season. In this study two main coccidiosis causing species, Emeria tenella and Emeria maxima were identified on the basis of their morphological feature and habitat (caeca and intestine), However, E. tenella was dominant compared to E. maxima. Conclusion: The study provides an insight to the occurrence of Emeria species which must be taken into consideration when rearing the broilers.

A study of urbanization effect to a precipitation pattern in a urban area (도시화가 도시지역 강우변화에 미치는 영향 연구)

  • Oh Tae Suk;Ahn Jae Hyun;Moon Young Il;Jung Min Su
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.894-899
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    • 2005
  • Since 1970s, rapid industrialization brought urbanization nationwide. In this paper, precipitation changes have been studied for Seoul and other 6 major cities using 31 years of precipitation data from 1973 to 2003. In addition, to consider the other global climatic impacts including El Nino events, precipitation change comparisons have been made between urban and rural areas. Thus, statistical analysis methods have been adopted for annual precipitation, summer precipitation, 1 hour annual maxima series, and 24 hour annual maxima series for both urban and rural areas. The result yields that annual and summer precipitation have been increased in urban areas compare to rural areas.

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Study of nitrate concentration in Najaf Abad aquifer using GIS

  • Tabatabaei, Javad;Gorji, Leila
    • Membrane and Water Treatment
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    • v.11 no.2
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    • pp.167-172
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    • 2020
  • The effectiveness of in situ sediment capping as a technique for heavy metal risk mitigation in Hyeongsan River estuary, South Korea was studied. Sites in the estuary were found previously to show moderate to high levels of contamination of mercury, methylmercury and other heavy metals. A 400 m x 50 m section of the river was selected for a thin layer capping demonstration, where the total area was divided into 4 sections capped with different combinations of capping materials (zeolite, AC/zeolite, AC/sand, zeolite/sand). Pore water concentrations in the different sites were studied using diffusive gradient in thin film (DGT) probes. All capping amendments showed reduction in the pore water concentration of the different heavy metals with top 5 cm showing %reduction greater than 90% for some heavy metals. The relative maxima for the different metals were found to be translated to lower depths with addition of the caps. For two-layered cap with AC, order of placement should be considered since AC can easily be displaced due to its relatively low density. Investigation of methylmercury (MeHg) in the site showed that MeHg and %MeHg in pore water corresponds well with maxima for sulfide, Fe and Mn suggesting mercury methylation as probably coupled with sulfate, Fe and Mn reduction in sediments. Our results showed that thin-layer capping of active sorbents AC and zeolite, in combination with passive sand caps, are potential remediation strategy for sediments contaminated with heavy metals.

The Influence of Long-range Transport on Springtime Nocturnal Ozone Enhancement in Seoul (봄철 서울지역 야간 오존농도 상승에 미치는 장거리 수송의 영향)

  • 오인보;김유근
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.4
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    • pp.503-514
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    • 2004
  • In Seoul metropolitan area, nocturnal variation of surface ozone concentrations observed at 27 monitoring sites from 1998 to 2002 showed that high ozone levels occurred frequently during the spring. Frequency distributions for nighttime ozone indicated that elevated concentrations in spring were influenced by advection of different air mass compared to other seasons. Surface wind analysis during the spring revealed that relatively strong southwesterly winds were associated with nocturnal ozone enhancement, which can be attributed to the regional transport of ozone. In order to identify the origin of nocturnal ozone enhancement in spring, 3-day backward trajectories were calculated by HYSPLIT 4 for the episode days and then classified. The results showed that NW, W, and SW flows, indicating influence of polluted air masses from the China continent, have 51% in a]1 the episode days, which suggest that the nocturnal ozone enhancement can occur under the effect of long-range transport of ozone-laden air mass on a regional scale. Case study of nocturnal ozone maxima associated with long-range transport was discussed in more detail in the light of meteorological conditions. Southwesterly synoptic flow along the outer edge of moving high-pressure system was found to be the important cause of nocturnal ozone maxima in Seoul. This flow could lead to be long-range transport of ozone that had effectively accumulated in the stagnating portion of the system located eastern coast of China. Low atmosphere soundings, backward trajectories, and elevated ozone and CO levels at the back-ground tiles gave evidence for regional effects on nocturnal ozone enhancement In Seoul.

A Study on engine characteristics of vibration using microcomputer (Microcomputer를 이용(利用)한 디젤기관(機關)의 진동특성(振動特性) 분석(分析)에 관(關)한 연구)

  • Kim, Sung Rai;Myung, Byung Soo
    • Korean Journal of Agricultural Science
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    • v.17 no.2
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    • pp.115-129
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    • 1990
  • This study was carried out to develop a microcomputer-based data acquisition system and software for analysis of engine vibration. Due to this development of system and software, studies on the vibration of engine was able to conduct efficiently. From the display of CRT, the outputs of test was compared and analysed on a zero-base motoring. The results obtained are summarized as follows : 1. Data acquisition system in microcomputer were designed and programmed and operated accurately. 2. The result of test was easily compared in monitoring of zero-base at color monitor. 3. This system and program developed was able to control the measuring intervals, no. of channels, and no. of data as wated. 4. The type of vibration of engine was type of bi-mode from the FFT and statistical analysis. 5. The maxima of engine vibration were 9.11 G at X-axis. 11.27 G at Y-axis, and 4.9 G at Z axis for full load of net output 6. The maxima of engine vibration unloaded were 4.28 G, 5.59 G, 2.68 G at 2200 rpm.

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Removing Baseline Drift in ECG Signal using Morphology-pair Operation and median value (Morphology-pair 연산과 중간 값을 이용한 심전도 신호의 기저선 변동 잡음 제거)

  • Park, Kil-Houm;Kim, Jeong-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.8
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    • pp.107-117
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    • 2014
  • This paper proposed the method of removing baseline drift by eliminating local maxima such as P, R, T-wave signal region and local minima Q, S-wave signal region. We applied morphology-pair operations improved from morphology operation to the ECG signal. To eliminate overshoot in the result of morphology-pair operation, we apply median value operation to the result of morphology-pair operation. We use MIT/BIH database to estimate the proposed algorithm. Experiment result show that proposed algorithm removing baseline drift effectively without orignal ECG signal distortion.

Preparation and Quality of Instant Gruel Using Pumpkin (밤호박을 이용한 즉석죽 제조 및 품질특성)

  • 정기태;주인옥;최정식
    • Food Science and Preservation
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    • v.8 no.1
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    • pp.74-78
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    • 2001
  • Instant gruel using pumpkin(Cucurbita maxima Duch var. Evis) was prepared and the optimum mixing ratio of ingredients and cooking method were examined by physicochemical characteristics and sensory tests. The optimum mixing ratio of materials were steamed pumpkin 78.4%, heated com 9.2%, roasted onion 4.6%, boiled redbean 6.9%, sugar 0.6%, salt 0.3% in overall acceptance of instant pumpkin gruel. In order to Felons the shelf-life, instant pumpkin gruel was packed using pouch pack(PE-CPP) and heated under the different conditions. After heat treatment, products were decreased colors value and increased acidity and viscosity The sensory evacuation of heated product after 5 days at 37$^{\circ}C$ was preferable at 120$^{\circ}C$ for 30∼40 min treatments.

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Pharmacological study of 'treenoponchomul'-an Ayurvedic diuretic preparation

  • Haque, Sabera;Hannan, JMA;Shahriar, Masum;Islam, M Naimul;Sattar, Mafruhi;Choudhuri, MSK
    • Advances in Traditional Medicine
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    • v.3 no.1
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    • pp.21-28
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    • 2003
  • The pharmacological effects of an Ayurvedic diuretic drug 'Treenoponchomul' (TPM) was investigated in animal model. The pharmacological actions of the test drug along with that of the components thereof, on the Central Nervous System (CNS) were studied. The drug under study TPM showed little effect on the CNS, the same can not be said about the components. The most prominent CNS depressant effect was observed with Saccharum officinarum Linn. (EE) in that it lowered the spontaneous motor activity as well the exploratory -behavior of the animals. An exploration retarding effect of moderate degree, was evident with Imperata cylindrica Beauv. (UU), and Phragmites maxima Blatter & McCann (NN). Although the test drug did not alter the normal locomotor and/ or exploratory behavior of the treated animals, it did significantly (p<0.01) lower the locomotion of the amphetamine induced hyperactive animals. TPM along with its components (especially Desmostachya bipinnata Stapf. Root, KU), significantly reduced the gastro-intestinal motility of the treated animals (p<0.01). The test drug and its components lowered the body weight of the treated animals, on being administered chronically (30 days), with EE being the only exception.

The Influence of the Cationic Surfactant on the Coloration of Chromogenic Reagents (I). The Dissociation Constants of Sulfophthalein Indicators in the Presence of Zephiramine (呈色詩藥의 發色에 미치는 陽이온 表面活性劑의 영향 (第1報). Zephiramine 의 存在下에서 여러가지 술포프탈레인 指示藥의 解離常數)

  • Su-Chan Moon
    • Journal of the Korean Chemical Society
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    • v.20 no.4
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    • pp.270-276
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    • 1976
  • The absorption spectra and the dissociation constants of various sulfophthaleins have been measured in the presence of a cationic surfactant. In the presence of 2.0 ${\times}$ 10-3 M zephiramine and an ionic strength of 0.05 at 25${\pm}1^{\circ}C$ the absorption maxima of the basic forms are shifted to red by 6${\sim}$21 nm and their molar absorptivities are increased, while the absorption maxima of the yellow forms are shifted to blue by 4${\sim}$20 nm and their molar absorptivities are decreased. The decreases in pKa values are of the order of ranging -1.38${\sim}$0.37. The characteristic of the observed changes has been explained by the assumption that the dye molecule adsorbed on micellar surface forms a stable coplanar structure easily and then the conjugation in the dye molecule is elevated.

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