• Title/Summary/Keyword: temperature type

Search Result 8,999, Processing Time 0.035 seconds

Geographic Variation in Shell Morphology of the Rock Shell, Thais clavigera (Gastropoda: Muricidae) According to Environmental Difference in Korean Coasts

  • Son Min Ho
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.36 no.6
    • /
    • pp.632-640
    • /
    • 2003
  • Geographic variation in shell morphology of Thais clavigera $(K\"{u}ster)$ (Gastropoda: Muricidae) was investigated using samples collected from 24 sites along the Korean coast. Multivariate statistical analysis was applied to 9 morphometric and 4 categorical variables. The shells of T. clavigera were classified into two distinct morph types (Type-W and -E). Temperature and salinity of the sampling sites were significantly correlated with the incidence of morph types. Relative abundance of Type-W (thin, yellowish brown shell with triangular nodules) was positively correlated with temperature and negatively correlated with salinity. In contrast, relative abundance of Type-E (thick, dark purple shell with round nodules) was negatively correlated with temperature and positively correlated with salinity. Possible correlation between environmental factors (temperature and salinity) and morphological variations in the shells were discussed.

Fabrication of Ceramic Thin Film Type Pressure Sensors for High-Temperature Applications and Their Characteristics (고온용 세라믹 박막형 압력센서의 제작과 그 특성)

  • 정귀상
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.9
    • /
    • pp.790-794
    • /
    • 2003
  • This paper describes the fabrication and characteristics of ceramic thin film type pressure sensors based on Ta-N strain gauges for high temperature applications. Ta-N thin-film strain gauges are deposited onto a thermally oxidized Si diaphragm by RF sputtering in an argon-nitrogen atmos[here($N_2$ gas ratio: 8%, annealing condition: 90$0^{\circ}C$, 1 hr.), patterned on a wheatstone bridge configuration, and used as pressure sensing elements with a high stability and a high gauge factor. The sensitivity is 1.097 ~ 1.21 mV/Vㆍkgf/$\textrm{cm}^2$ in the temperature range of 25 ~ 200 $^{\circ}C$ and the maximum non-linearity resistance), non-linearity than existing Si piezoresistive pressure sensors. The fabricated ceramic thin-film type pressure sensor is expected to be usefully applied as pressure and load sensors that os operable under high-temperature.

Development of a Contact Type Temperature Sensor Using Single Crystal Silicon Thermopile (단결정 실리콘 써모파일을 이용한 접촉형 온도센서 개발)

  • Lee, Young-Tae;Lee, You-Na;Lee, Wang-Hoon
    • Journal of Sensor Science and Technology
    • /
    • v.22 no.5
    • /
    • pp.369-373
    • /
    • 2013
  • In this paper, we developed contact type temperature sensor with single crystal silicon strip thermopile. This sensor consists of 15 p-type single crystal silicon strips, 17 n-types and contact electrodes on silicon dioxide silicon membrane. The result of electromotive force measuring showed very good characteristic as $15.18mV/^{\circ}C$ when temperature difference between the two ends of the thermopile occurs by applying thermal contact on the thermopile which was fabricated with silicon strip of $200{\mu}m$ length, $20{\mu}m$ width, $1{\mu}m$ thickness.

Experimental study on combustion characteristics of oxy-fuel glass melting furnace (순산소를 이용한 유리 용해로의 연소특성에 관한 실험적 연구)

  • Kim, Se-Won;Ahn, Jae-Hyun;Kim, Yong-Mo;Shin, Myung-Chul
    • Journal of the Korean Society of Combustion
    • /
    • v.9 no.1
    • /
    • pp.1-10
    • /
    • 2004
  • The results of a series of experiments executed by using two pilot-scale oxy-fuel burners are presented. The oxy-fuel burners are designed for maximum capacity of 50,000kcal/hr, 200,000kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, and swirl vane angle on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple at various points of the flame. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and momentum. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, optimum burner type, excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

  • PDF

Control of Compressors and Electronic Expansion Valve considering the Safe Operation of a Tandem-type Air-conditioning system (텐덤형 냉방시스템의 안전운전을 고려한 압축기와 전자팽창밸브 제어)

  • Han, Do-Young;Kim, Jae-Hyun
    • Proceedings of the SAREK Conference
    • /
    • 2006.06a
    • /
    • pp.675-680
    • /
    • 2006
  • Capacities of a tandem-type air-conditioner may be modulated by turning on and off of multiple compressors, and adjusting the position of a electronic expansion valve. In this study, control algorithms for compressors and a electronic expansion valve were developed by using fuzzy logics. The pressure control algorithm was also developed for the safe operation of compressors. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature,

  • PDF

Convection Effects on PGSE-NMR Self-Diffusion Measurements at Low Temperature: Investigation into Sources of Induced Convective Flows

  • Chung, Kee-Choo;Yu, Hyo-Yeon;Ahn, Sang-Doo
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.6
    • /
    • pp.1970-1974
    • /
    • 2011
  • The effects of convection on the measurement of the diffusion coefficients of liquids by the pulsed gradient spin echo (PGSE) NMR method at low temperature are discussed. To examine the generation of convective flows, we used four different types of sample tubes in the diffusion measurements with temperature variation; a normal 5 mm NMR tube, a Shigemi tube, an ELISE type tube, and a capillary tube. Below room temperature, the calculated diffusion coefficients of chloroform in 5 mm o.d. type tubes increased with decreasing temperature, while those in the capillary tube decreased linearly. The convective flow was found to be significant even at low temperature and it seemed to be mainly induced by the transverse temperature gradient. It was also found that the capillary tube was most appropriate to measure the diffusion coefficients, since its small diameter is effective in suppressing the convective flows at both high and low temperatures.

CREEP-FATIGUE CRACK GROWTH AND CREEP RUPTURE BEHAVIOR IN TYPE 316 STAINLESS STEELS- EFFECT OF HOLD TIME AND AGING TREATMENT

  • Mi, J.W.;Won, S.J.;Kim, M.J.;Lim, B.S.
    • International Journal of Automotive Technology
    • /
    • v.1 no.2
    • /
    • pp.71-77
    • /
    • 2000
  • High temperature materials in service are subjected to mechanical damage due to operating load and metallurgical damage due to operating temperature. Therefore, when designing or assessing life of high temperature components, both factors must be considered. In this paper, the effect of tensile hold time on high temperature fatigue crack growth and long term prior thermal aging heat treatment on creep rupture behavior were investigated using STS 316L and STS 316 austenitic stainless steels, which are widely used for high temperature components like in automotive exhaust and piping systems. In high temperature fatigue crack growth tests using STS 316L, as tensile hold time increased, crack growth rate decreased in relatively short tensile hold time region. In long term aged specimens, cavity type microcracks have been observed at the interface of grain boundary and coarsened carbide.

  • PDF

Numerical Analysis on the Characteristic of Thermal Distribution for High Temperature Operating Battery Module (고온 작동형 전지모듈 온도분포 특성에 관한 수치해석)

  • Yi, Chung Seob;Lee, Byung Ho
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.12 no.5
    • /
    • pp.102-108
    • /
    • 2013
  • In this study, the experiment result and numerical analysis on temperature distribution of a secondary battery module for high temperature operation type were compared. Because experimental battery has been in danger of explosions, experiment on temperature distribution was carried out using dummy batteries. Study on NAS battery module, which is secondary battery of high temperature operation type, is as follows ; Test result showed that battery's temperature is in steady state uniformly after 8 hours in each section. It is similar to experimental result for temperature distribution from the result of numerical analysis, and it takes about 8.5 hours to the $300^{\circ}C$.

Laundering Factors in Soil Removal

  • Kadolph, Sara J.;Schofield-Tomschin, Sherryl A.;Kwon, Young-Ah
    • Fashion & Textile Research Journal
    • /
    • v.3 no.5
    • /
    • pp.455-465
    • /
    • 2001
  • Assessing soil removal is of interest to the washing machine industry because of government-mandated energy savings and changes in detergent formulation and consumer laundry practices. We designed this study to examine the laundry process from a holistic perspective by integrating factors perceived to be of importance. Our purpose was to assess the impact of selected variables (fabric and soil type, wash temperature and time. detergent amount, and degree of agitation) on soil removal using accelerated laundry conditions. We used the Taguchi method to develop the research design and ANOVA to analyze the data. Although soil removal was affected by fabric type, soil type, type and amount of detergent, degree of agitation, wash time and temperature, and water hardness and volume, wash temperature was the most significant variable.

  • PDF

Study on the Properties of Dam Concrete Using Low Heat Portland Cement (저열 포틀랜드 시멘트를 사용한 댐 콘크리트의 특성에 관한 연구)

  • Son, Young-Jun;Ha, Jae-Dam;Um, Tai-Sun;Lee, Jong-Ryul;Kim, Tae-Hong
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2006.05b
    • /
    • pp.445-448
    • /
    • 2006
  • In order to control the temperature crack of massive dam concrete, the selection of appropriate materials like binder, aggregates etc., is essential. To select the optimal mix proportion, ordinary portland cement(Type I) plus 25% of fly ash and low heat portland cement(Type IV) are used as binder, and 80mm of coarse aggregates are used to reduce the amount of binder and compare the compressive strength, hydration temperature and crack index. The results of this study are as following. 1. The strength of Type IV cement is advantageous on the long-term age. 2. According to the temperature measured on mock-up$(1.5m{\times}1.5m{\times}1.5m)$, and realized the thermal analysis, the Type IV cement carried out advantageous to control the thermal crack.

  • PDF