• Title/Summary/Keyword: thermo-sensitive

Search Result 98, Processing Time 0.033 seconds

A Study on Characteristics of Jointed Rock Masses and Thermo-hydro-mechanical Behavior of Rock Mass under High Temperature (방사성 폐기물 저장을 위한 불연속 암반의 특성 및 고온하에서의 암반의 수리열역학적 상호작용에 관한 연구)

  • 이희근;김영근;이희석
    • Tunnel and Underground Space
    • /
    • v.8 no.3
    • /
    • pp.184-193
    • /
    • 1998
  • In order to dispose radioactive wastes safely, it is needed to understand the mechanical, thermal, fluid behavior of rockmass and physico-chemical interactions between rockmass and water. Also, the knowledge about mechanical and hydraulic properties of rocks is required to predict and to model many conditions of geological structure, underground in-situ stress, folding, hot water interaction, intrusion of magma, plate tectonics etc. This study is based on researches about rock mechanics issues associated with a waste disposal in deep rockmass. This paper includes the mechanical and hydraulic behavior of rocks in varying temperature conditions, thermo-hydro-mechanical coupling analysis in rock mass and deformation behavior of discontinuous rocks. The mechanical properties were measured with Interaken rock mechanics testing systems and hydraulic properties were measured with transient pulse permeability measuring systems. In all results, rock properties were sensitive to temperature variation.

  • PDF

Thermo-mechanical Deformation Analysis of Filu Chip PBGA Packages Subjected to Temperature Change (Flip Chip PBGA 패키지의 온도변화에 대한 변형거동 해석)

  • Joo, Jin-Won;Kim, Do-Hyung
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.13 no.4
    • /
    • pp.17-25
    • /
    • 2006
  • Thermo-mechanical behavior of flip-chip plastic ball grid array (FC-PBGA) packages are characterized by high sensitive $moir\'{e}$ interferometry. $Moir\'{e}$ fringe patterns are recorded and analyzed for several temperatures. Deformation analysis of bending displacements of the packages and average strains in the solder balls for both single and double-sided package assemblies are presented. The bending displacement of the double-sided package assembly is smaller than that of the single-sided one because of its symmetric structure. The largest effective strain occurred at the solder ball located on the edge of the chip and its magnitude of the double-sided package assembly is greater than that of single-sided one by 50%.

  • PDF

Temperature-Sensitive Polymers Adhered on FO Membrane as Drawing Agents (자극감응성 유도용질로서 정삼투막에 부착된 온도감응성 고분자)

  • Lee, Chong-Cheon;Lee, Jonghwi
    • Polymer(Korea)
    • /
    • v.38 no.5
    • /
    • pp.626-631
    • /
    • 2014
  • Water purification requires a large amount of energy that can cause pollution problems. For this reason, forward osmosis (FO) has attracted intense interest that required a relatively low amount of energy for water purification. The forward osmosis has a serious problem that it needs drawing agents creating osmotic pressure to extract water from contaminated water. In this study, a copolymer of zwitterionic moiety and an interpenetrating polymer network (IPN) hydrogel based on thermo-responsive polymer hydrogel, poly(N-isopropylacrylamide) (PNIPAM) were prepared and attached on FO membranes, which successfully played the role of drawing agents. In the copolymer hydrogel, its swelling ratio was improved, but thermo-sensitivity was decreased. The swelling ratio and thermo-sensitivity of IPN hydrogel was lowered. We could confirm that swelling ratio is related to osmotic pressure.

Poloxamer 407 Hydrogels for Intravesical Instillation to Mouse Bladder: Gel-Forming Capacity and Retention Performance

  • Kim, Sang Hyun;Kim, Sung Rae;Yoon, Ho Yub;Chang, In Ho;Whang, Young Mi;Cho, Min Ji;Kim, Myeong Joo;Kim, Soo Yeon;Lee, Sang Jin;Choi, Young Wook
    • The Korean Journal of Urological Oncology
    • /
    • 제15권3호
    • /
    • pp.178-186
    • /
    • 2017
  • Purpose: Poloxamer 407 (P407) thermo-sensitive hydrogel formulations were developed to enhance the retention time in the urinary bladder after intravesical instillation. Materials and Methods: P407 hydrogels (P407Gels) containing 0.2 w/w% fluorescein isothiocyanate dextran (FD, MW 4 kDa) as a fluorescent probe were prepared by the cold method with different concentrations of the polymer (20, 25, and 30 w/w%). The gel-forming capacities were characterized in terms of gelation temperature (G-Temp), gelation time (G-Time), and gel duration (G-Dur). Homogenous dispersion of the probe throughout the hydrogel was observed by using fluorescence microscopy. The in vitro bladder simulation model was established to evaluate the retention and drug release properties. P407Gels in the solution state were administered to nude mice via urinary instillation, and the in vivo retention behavior of P407Gels was visualized by using an in vivo imaging system (IVIS). Results: P407Gels showed a thermo-reversible phase transition at $4^{\circ}C$ (refrigerated; sol) and $37^{\circ}C$ (body temperature; gel). The G-Temp, G-Time, and G-Dur of FD-free P407Gels were approximately $10^{\circ}C-20^{\circ}C$, 12-30 seconds, and 12-35 hours, respectively, and were not altered by the addition of FD. Fluorescence imaging showed that FD was spread homogenously in the gelled P407 solution. In a bladder simulation model, even after repeated periodic filling-emptying cycles, the hydrogel formulation displayed excellent retention with continuous release of the probe over 8 hours. The FD release from P407Gels and the erosion of the gel, both of which followed zero-order kinetics, had a linear relationship ($r^2=0.988$). IVIS demonstrated that the intravesical retention time of P407Gels was over 4 hours, which was longer than that of the FD solution (<1 hour), even though periodic urination occurred in the mice. Conclusions: FD release from P407Gels was erosion-controlled. P407Gels represent a promising system to enhance intravesical retention with extended drug delivery.

Comparison of temperature measurements methods to investigate the causes of deformation of packaging materials during microwave heating (전자레인지의 가열조리 시 포장재의 열변형 원인 규명을 위한 온도 측정 방법 비교)

  • Yoon, Chan Suk;Lee, Hwa Shin;Pfeiffer, Thomas;Cho, Ah Reum;Moon, Sang Kwon;Lee, Keun Taik
    • Food Science and Preservation
    • /
    • v.23 no.3
    • /
    • pp.422-431
    • /
    • 2016
  • To investigate the causes of the thermal deformations of packaging materials when microwave-heating ready-to-eat sauce products packaged in stand-up pouches, patterns of temperature changes were determined using an infra-red thermal imaging camera, a thermo-sensitive tape, and a fiver-optic thermometer. The temperature distributions of spicy chicken sauce and Indian curry samples in a stand-up pouch were found to be uneven during micrewave heating. A sharp increase in the temperature was detected, especially above the filling layers and in the corners of sealing layers of the package. The temperature measurements using an infra-red thermal imaging camera are restricted to the surface, and therefore might underestimate the actual temperature. Using a thermo-sensitive tape, temperature up to $200^{\circ}C$ were measured in the spicy chicken sauce sample showing package deformation. When the temperature is measured using a fiber-optic thermometer, it is crucial to have precise sensor performance to accurately measure the temperature in a narrow hot-spot area of the package. In this experiment, the fiber-optic thermometer was attached to a GaAs crystal sensor, which obtained more sensitive and accurate temperature measurements than those by a convectional sensor.

A Systematic Review of effect on Heat-sensitive Moxibustion for Benign Prostatic Hyperplasia (전립선비대증에 대한 열민구(熱敏灸)의 효과에 관한 체계적 문헌 고찰)

  • Kim, MinSeok;Ju, HongMin;Kim, MinHwa;Park, SunYoung;Yun, YoungJu;Park, SeongHa
    • The Journal of Korean Medicine
    • /
    • v.42 no.3
    • /
    • pp.153-164
    • /
    • 2021
  • Objectives: The aim of this study is to investigate the effect of Heat-sensitive Moxibustion on Benign Prostatic Hyperplasia Methods: We searched articles from Academic Journals(CAJ) online databases, Oriental Medicine Advanced Searching Integrated System (OASIS), Searching key words were '前列腺增生', '熱敏灸' and '열민구', '전립선비대'. The search range included randomized controlled trials (RCTs). Among the articles published to 2020, 10 articles were found. After review the title, abstract and original, 3 articles were selected finally to rule out treatment combined with completely different treatments. Result: The Heat-sensitive moxibustion at acupoints in the treatment of Benign prostatic hyperplasia were significantly superior to control group after treatment in the symptoms of patients, IPSS, QOL, PVR and Qmax(P<0.05). The Heat-sensitive moxibustion can significantly reduce the incidence of temporary urinary incontinence after Transurethral resection of the prostate(TURP) and improve life quality and satisfaction of patients(P<0.05). The individualized desensitization saturated time and amount of Heat-sensitive moxibustion is superior effective to general amount and time of traditional moxibustion in the total effective rate, IPSS, Ru and Qmax(P<0.01) for Benign prostatic hyperplasia. Conclusion: Heat sensitive moxibustion directly transfer heat to the source of a disease. So it can be considered as a good treatment for Benign prostate hypertrophy. It was also shown a better effect on BPH compared to traditional moxibustion, According to the thermo principles of tumor, if the tumor cell's death temperature of 43℃ is reached, that can cause tumor degeneration. Therefore I think Heat sensitive moxibustion can be applied to various tumor disease. The results of this study could be applied to clinical treatment of BPH. However, additional large-scale clinical researches should be conducted.

Estimation of Neutron Energy Spectrum of Cf-252 using Single Bonner Sphere with TLD-600 and TLD-700 (단일 보너구와 TLD-600 및 TLD-700을 이용한 Cf-252의 중성자 에너지 스펙트럼 평가)

  • Kim, Sunghwan;Cheon, Jongkyu;Lee, Jae Jin;Nam, Uk-Won
    • Journal of Sensor Science and Technology
    • /
    • v.22 no.3
    • /
    • pp.223-226
    • /
    • 2013
  • We designed a single polyethylene bonner sphere with several thermo-luminescence dosimeters (TLD), for measurement of neutron energy spectrum. For the separation of the neutron dosage in the neutron-gamma mixed field, we used 21 ea TLD-600s and TLD-700s, respectively. Because, TLD-600 is sensitive to neutron and gamma rays, and, TLD-700 is sensitive only to gamma-rays, we could determine the each dose by neutron and gamma rays. The neutron response function of the bonner sphere with TLDs was calculated by MCNPX (ver. 2.5.0) Monte Carlo simulation in the energy range from $10^{-1}$ to 20 MeV. For the Cf-252 standard neutron source in KRISS, we could estimate the neutron energy spectrum by unfolding method using the response function.

Thermocontrol of Solute Permeation across Polymer Memberane Composed of Poly(N, N-dimethylaminoethyl methacrylate) and Its Copolymers

  • Yuk, Soon-Hon;Cho, Sun-Hang
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.6 no.4
    • /
    • pp.274-278
    • /
    • 2001
  • Polymer membranes composed of N, N-dimethylaminoethyl methaccrylate(DMAEMA) and acrylamide(AAm)(or ethyl acrylamide(EAAm) were prepared to demonstrated the thermo-control of solute permeation. Poly DMEMA has a lower critical solution temperature(LCST) at around 50$\^{C}$ in water, With the copolymerization of DMAEMA with AAm (or EAAm) a shift in the LCST to a lowere temperature was observed, probably due to the formation of hydrogen bonds between the amide and N-N-dimethylamino groups. However, the temperature-induced phase transition of poly(DMAEMA-co-EAAm) did not show a similar trend to that of poly(DMAEMA- co-AAm) in the gel state. The hydrogen bonds in poly(DMAEMA-co-EAAm) were significantly disrupted with the formation a gel network, which led to a difference in the swilling behavior of polymer gels in response to temperature. To apply these polymers to temperature-sensitive sol-ute permeation, polymer membranes were prepared. The permeation pattern of hydrocortisone, used as the model solute, was explained based on the temperature-sensitive swelling behavior of the polymer membranes.

  • PDF

Aerodynamic Heating Characteristics Over a Protuberance in Hypersonic Flows Using Fast Response Thermo Gauges

  • Lee, Hyoung-Jin;Lee, Bok-Jin;Jeung, In-Seuck;Kim, Seoung-Lyoung;Kim, In-Sun
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.11 no.3
    • /
    • pp.193-200
    • /
    • 2010
  • Through experimental investigations utilizing hypersonic shock tunnel-coaxial thermocouples as well as blow down hypersonic wind tunnel-temperature sensitive paints, the heat flux and the temperature over a protuberance were measured and analyzed. The experimental data were subsequently compared to heat flux data that was obtained by using blow down hypersonic wind tunnel and heat flux gauges. According to the comparison, both sets of data illustrated correlation with one another. The measured heat flux was large when the height of the protuberance was large. Experimental results show that heat flux measurements taken at higher locations were greater than those taken at lower locations. For high protuberances, a severe jump in the heat flux was observed, ranging in values within 0.6-0.7 of the height of the protuberances. However, when the protuberance was sufficiently short, a rise in the heat flux was rarely observed as the protuberance was totally submerged under the separation region.

Basic Studies for the Breeding of High Protein Rice -V. Effect of planting and harvesting date on the amylose and protein content in rice grain- (수도 고단백계통 육성을 위한 기초적 연구 -V. 파종 및 수확시기가 쌀의 Amylose 및 단백질함량에 미치는 영향-)

  • Huhn-Pal Moon;Mun-Hue Heu
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.19
    • /
    • pp.14-20
    • /
    • 1975
  • In order to obtain the fundamental informations on the variation of protein and amylose content in rice grain, 4 varieties were subjected to the 5 different harvesting with 5 different plantings. Amylose content in the rice grain were increased by later planting. Protein content of thermo-sensitive rice varieties were decreased while those of photo-sensitive varieties were increased by delayed planting. Interactions among planting date, variety and harvesting date were highly significant for amylose content, but not significant for protein content.

  • PDF