• Title/Summary/Keyword: residual time

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Effect of Aggregate on Mechanical Properties of Ultra-High Strength Concrete Exposed to High Temperature (고온을 받은 초고강도 콘크리트의 역학적 특성에 관한 골재의 영향)

  • Kim, Young-Sun;Choi, Hyoung-Gil;Ohmiya, Yoshifumi;Kim, Gyu-Yong
    • Journal of the Korea Concrete Institute
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    • v.23 no.4
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    • pp.431-440
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    • 2011
  • Concrete structures exposed to fire produce changes in their internal structure, resulting in their service life reduction due to the deterioration of its strength and performance capacity. The deterioration level are dependent on the temperature, exposure time, concrete mix proportions, aggregate property, and material properties. This study was performed to evaluate the thermal behavior of ultra-high strength concrete for the parameters of water to cement ratio (compressive strength), fine to total aggregate ratio, and maximum coarse aggregate size. At room temperature and $500^{\circ}C$, tests of ultrasonic pulse velocity, resonance frequency, static modulus of elasticity, and compressive strength are performed using ${\varnothing}100{\times}200\;mm$ cylindrical concrete specimens. The results showed that the residual mechanical properties of ultra-high strength concrete heated to $500^{\circ}C$ is influenced by variation of a water to binder ratio, fine to total aggregate ratio, and maximum coarse aggregate size.

Comparative observations of lingualized occlusion and monoplane occlusion in the treatment of severe atrophy of edentulous mandible (심한 하악 치조골 흡수를 보이는 환자에서 설측 교두 교합과 단일평면 교합을 비교 관찰한 의치 수복 증례)

  • Ahn, Gyo-zin;Lee, Joon-Seok
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.2
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    • pp.127-136
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    • 2018
  • The patient who has severely absorbed residual ridges, treatments are challenging to satisfy many factors: support, retention, stability, etc. The neutral zone or monoplane occlusion with non-anatomical tooth would be helpful to get additional retention and stability. The monoplane occlusion has been used long time because it can eliminate horizontal forces and many other advantages. The lingualized occlusion was introduced to improve chewing efficiency and esthetics. But from a stability aspect, it seems controversy between monoplane occlusion and lingualized occlusion. This case report shows the results of the treat two flat residual ridge patients using functional impression; piezography, and made 2 other dentures with monoplane and lingualized occlusion that patient can select denture.

A Study on the structures of flow and water quality in the Kitan strait (Kitan 해협의 유동 및 수질구조에 관한 연구)

  • ;;Nakatsuji Keiji
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.15 no.4
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    • pp.259-268
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    • 2003
  • The damage of water quality like red tide occurs every year inspite of the total load regulation of pollutant inflows from land such as COD, phosphorus and so on around Seto inland sea in Japan. It is attributed to the increase of primary production due to eutrophication. and the rising and settling from the sediment containing nutrient salt. Furthermore, the recent research shows that nutrient salt such as nitrogen and phosphorus, flows into Kii channel from land as well as the Pacific ocean. To investigate the distribution of water quality and flow and residual current in Kitan strait, the field observations were carried out. The field data were obtained a time each season from 1999 to 2002. The results of observations and data of other research institution are used to understand the mechanism of pollution in the strait.

Rheological Properties of Rough Rice(I) -Stress Relaxation of Rough Rice Kernel- (벼의 리올러지 특성(特性)(I) -곡립(穀粒)의 응력이완(應力弛緩)-)

  • Kim, M.S.;Kim, S.R.;Park, J.M.
    • Journal of Biosystems Engineering
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    • v.15 no.3
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    • pp.207-218
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    • 1990
  • Grains display characteristics of both elastic bodies and viscous fluids when they are subjected to mechanical treatments in harvesting, handling, and processing. This viscoelastic behavior of grains when mechanically stressed must be fully understood to establish maximum machine efficiency and have a minimum degree of grain damage and the highest quality of the final product. The studies were conducted to examine the effect of the moisture content, the loading rate and the initial deformation on the stress relaxation behavior of whole kernel of rough rice, and develop the rheological model to represent its stress relaxation behavior. The following results were obtained from the study. 1. Moisture content had the greatest influence on the initial portion of the relaxation curve. With elapsing time the lower moisture content resulted in the lower residual stress for the Japonica-type rough rice and vice versa for the Indica-type rough rice. But within the ranges of moisture content tested, the degree of stress relaxation per unit strain on the Indica-type rough rice was a little higher than those on the Japonica-type rough rice. 2. The slower loading rate resulted in less initial stress. The decreasing trend of residual stress for all the samples tested with increasing loading rate was shown. 3. The higher initial deformation for all the samples resulted in less initial stress. The increasing of amount of stress relaxation per unit strain with increase of initial stress indicated that viscoelastic properties of rough rice depended not only upon duration of load applied but also initial stress applied. This means that rough rice is nonlinear viscoelastic material. 4. The compression stress relaxation properties of rough rice kernel can be described by a generalized Maxwell model representing by the Maxwell elements.

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A Clinical Study to Assess the Safety of GyoGam-Dan (교감단의 안정성과 임상적 적용에 대한 연구)

  • Kang, Hyung-Won;Kim, Ji-Hwon;Kim, Jin-Heong;Lee, Chung-Sik;Lee, Sang-Eon;Kim, Tae-Heon;Kim, Tae-Heon
    • Journal of Oriental Neuropsychiatry
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    • v.19 no.3
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    • pp.195-203
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    • 2008
  • Objective: 'GyoGam-Dan' is known as a medicine to cure depression in Donguibogam (traditional Korean oriental medicine book). GyoGam-dan which is composed of Cyperi Rhizoma L. and Poria cum Radix pini has been used by basic prescription of asymptom related to all kinds of Qi(氣) disease. Although it has been clinically used for a long time, its safety have never been proved till now. Methods: We had collected data of 610 cases of patients taking 'GyoGam-Dan' at Wonkwang univ. oriental medical center for a period of three years (2005.3.09-2008.04.30). On the patients' blood, the levels of LFT and RFT were examined and the residual levels of heavy metals and pesticides were measured. Results: There were 610 patients who had taken GyoGam-Dan for about three years. In the patients, the most common diseases is depression, followed by palpitation, and then insomnia. Among the patients' estimations on its effectiveness, there were many of positive ones. The blood analyses of patients who had taken GyoGam-Dan did not show any problems and moreover there was not any problems in the levels of residual heavy metals and agricultural pesticides. Taken together, GyoGam-Dan was proved to be a safe medicine for health. Conclusions: Our clinical and chemical studies show that GyoGam-dan has the anti-stress effect and is a safe medicine of which side effect does not exist. Hereafter, Nigorous clinical trial on GyoGam-dan is required.

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New Speech Enhancement Method using Psychoacoustic Criteria (심리 음향 기준을 이용한 새로운 음질 개선 방법)

  • 김대경;박장식;손경식
    • Journal of Korea Multimedia Society
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    • v.4 no.1
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    • pp.56-66
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    • 2001
  • The spectral subtraction algorithm using a criterion based on the human perception has been recently developed. The speech processed with Virag's algorithm sounds more pleasant to a human listener than those obtained by the classical methods. However, Virag's algorithm requires a robust voice activity detector (VAD). In the ESS (extended spectral subtraction) algorithm without VAD, the residual noise becomes more noticeable as the SNR decrease. In this paper we propose a new speech enhancement method, the combination of Wiener filter and spectral subtraction based on noise masking characteristics in the human auditory system. There is no need of VAD because the noise can be successively updated even during speech activity using Wiener filter. The adjustment of the subtraction parameter based on the masking threshold makes the residual noise inaudible. The proposed method has been compared with conventional spectral subtraction algorithms. Objective and subjective evaluation of the proposed system is performed with several noise types having different time-frequency distributions. The application of objective measures, the study of the speech spectrograms, as well as subjective listening tests, confirm that the enhanced speech with proposed algorithm is more pleasant to a human listener.

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Construction of an Industrial Brewing Yeast Strain to Manufacture Beer with Low Caloric Content and Improved Flavor

  • Wang, Jin-Jing;Wang, Zhao-Yue;Liu, Xi-Feng;Guo, Xue-Na;He, Xiu-Ping;Wense, Pierre Christian;Zhang, Bo-Run
    • Journal of Microbiology and Biotechnology
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    • v.20 no.4
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    • pp.767-774
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    • 2010
  • In this study, the problems of high caloric content, increased maturation time, and off-flavors in commercial beer manufacture arising from residual sugar, diacetyl, and acetaldehyde levels were addressed. A recombinant industrial brewing yeast strain (TQ1) was generated from T1 [Lipomyces starkeyi dextranase gene (LSD1) introduced, ${\alpha}$-acetohydroxyacid synthase gene (ILV2) disrupted] by introducing Saccharomyces cerevisiae glucoamylase (SGA1) and a strong promoter (PGK1), while disrupting the gene coding alcohol dehydrogenase (ADH2). The highest glucoamylase activity for TQ1 was 93.26 U/ml compared with host strain T1 (12.36 U/ml) and wild-type industrial yeast strain YSF5 (10.39 U/ml), respectively. European Brewery Convention (EBC) tube fermentation tests comparing the fermentation broths of TQ1 with T1 and YSF5 showed that the real extracts were reduced by 15.79% and 22.47%; the main residual maltotriose concentrations were reduced by 13.75% and 18.82%; the caloric contents were reduced by 27.18 and 35.39 calories per 12 oz. Owing to the disruption of the ADH2 gene in TQ1, the off-flavor acetaldehyde concentrations in the fermentation broth were 9.43% and 13.28%, respectively, lower than that of T1 and YSF5. No heterologous DNA sequences or drug resistance genes were introduced into TQ1. Hence, the gene manipulations in this work properly solved the addressed problems in commercial beer manufacture.

A Study on the Leak-Proof of Full Containment Type Prestressed Concrete Structure (완전 밀폐형 PC 구조물의 누설 안전성에 관한 연구)

  • Kim Chung Kyun;Cho Seung Hyun
    • Journal of the Korean Institute of Gas
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    • v.5 no.4 s.16
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    • pp.85-91
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    • 2001
  • This paper presents safety analysis of LNG leakage in a prestressed concrete outer tank, which is strongly related on the leak checking effects of the PC structure with and without a residual compression zone based on the BS 7777 codes. The full containment type outer tank which is constructed by a prestressed concrete may be destroyed by leaked cryogenic fluids. The FE calculated results show that the total leak checking time of the PC structure with $10\%$ residual compression zone is about 9 days for $-162^{\circ}C$ liquids. But, three primary pumps in an inner tank may operate to send cryogenic fluids for 6 days, which are stored in an inner tank of $140,000m^3$ capacity This means that the prestressed concrete outer tank may be safe for $-162^{\circ}C$ cryogenic fluids leaked from the demolished inner tank.

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Sonication Effects on Froth Flotation for Deinking from Old Newspaper(ONP) (폐신문지(廢新聞紙)(ONP)로부터 부유선별(浮遊選別)을 이용한 잉크분리(分離)시 초음파처리(超音波處理) 효과(效果))

  • Lim, Gwang Il;Hwang, In Sung;Kim, Joung Woon;You, Kwang Suk;Ahn, Ji Whan;Han, Choon
    • Resources Recycling
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    • v.21 no.5
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    • pp.44-49
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    • 2012
  • In this study, the sonication method was applied to remove ink from old newspaper(ONP) using flotation. Results indicated increased whiteness and effective residual ink concentration (ERIC) with longer disintegration. Therefore 58% of whiteness and 182.9 ppm ERIC were obtained for 30 minutes of disintegration time without the change in yield. Longer disintegration than 30 minutes had no effects on whiteness without the application of ultra-sonication. On the other hand, higher than 58% of whiteness was achieved in 2 minutes of disintegration when the ultra-sonication was applied. The highest whiteness (59.32 %) was obtained by applying sonication for 20 minutes and froth flotation with kerosene as a collector under the alkaline condition (pH 11).

Solid-State Fermentation for the Production of Meroparamycin by Streptomyces sp. strain MAR01

  • El-Naggar, Moustafa Y.;El-Assar, Samy A.;Abdul-Gawad, Sahar M.
    • Journal of Microbiology and Biotechnology
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    • v.19 no.5
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    • pp.468-473
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    • 2009
  • The antibiotic meroparamycin was produced in the free culture system of Streptomyces sp. strain MAR01. Five solid substrates (rice, wheat bran, Quaker, bread, and ground corn) were screened for their ability to support meroparamycin production in solid-state fermentation. In batch culture, wheat bran recorded the highest antibacterial activity with the lowest residual substrate values. The highest residual substrate values were recorded for both ground corn and Quaker. On the other hand, no antibacterial activity was detected for rice as a solid substrate. The use of the original strength of starch-nitrate medium in the solid-state fermentation gave a lower antibacterial activity compared with the free culture system. Doubling the strength of this medium resulted in the increase in the activity to be equivalent to the free culture. The initial pH (7.0) of the culture medium and 2 ml of spore suspension (1 ml contains $5{\times}10^{9}spores/ml$) were the optima for antibiotic production. The water was the best eluent for the extraction of the antibiotic from the solid-state culture. Ten min was enough time to extract the antibiotic using a mixer, whereas, 60 min was required when shaking was applied. Semicontinuous production of meroparamycin using a percolation method demonstrated a more or less constant antibacterial activity over 4 runs ($450-480{\mu}g/ml$). The semicontinuous production of the antibiotic was monitored in a fixed-bed bioreactor and the maximum activity was attained after the fourth run ($510{\mu}g/ml$) and the overall process continued for 85 days.