• Title/Summary/Keyword: relative velocity

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Drying and Shrinking Characteristics of Food 1. Shrinking Phenomena during Drying of Sea Tangle (식품의 건조 및 수축특성에 관한 연구 - 1. 다시마 건조중의 수축현상 -)

  • CHO Duck-Jae;HUR Jong-Hwa;CHUNG Soo-Yeol
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.1
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    • pp.11-15
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    • 1988
  • Square slices of sea tangle was dried in constant condition of thickness (1.54mm), air temperature $(50^{\circ}C)$, relative humidity $(30\%)$ and air velocity (0.4m/s). The shrunk surface area and the shrinking rate were investigated. The results obtained are summarized as follows : 1) Comparing the shrinking of transverse section with that of vertical section, the transverse section was proceeded more double shrinkage than vertical section. 2) The shrunk surface area curve showed nearly a linear shrinkage up to 90min of drying time. 3) The shrinking rate was rapidly increased in first falling rate period, and was largest in the early period of second falling rate period.

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Assessment of Tissue Perfusion Following Conventional Liposuction of Perforator-Based Abdominal Flaps

  • Dogan, Zeynep Deniz Akdeniz;Sacak, Bulent;Yalcin, Dogus;Pilanci, Ozgur;Tuncer, Fatma Betul;Celebiler, Ozhan
    • Archives of Plastic Surgery
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    • v.44 no.2
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    • pp.109-116
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    • 2017
  • Background The effect of liposuction on the perforators of the lower abdominal wall has been investigated in several studies. There are controversial results in the literature that have primarily demonstrated the number and patency of the perforators. The aim of this study was to determine the effect of liposuction on the perfusion of perforator-based abdominal flaps using a combined laser-Doppler spectrophotometer (O2C, Oxygen to See, LEA Medizintechnik). Methods Nine female patients undergoing classical abdominoplasty were included in the study. Perforators and the perfusion zones of the deep inferior epigastric artery flap were marked on the patient's abdominal wall. Flap perfusion was quantitatively assessed by measuring blood flow, velocity, capillary oxygen saturation, and relative amount of hemoglobin for each zone preoperatively, after tumescent solution infiltration, following elevation of the flap on a single perforator, and after deep and superficial liposuction, respectively. Results The measurements taken after elevation of the flap were not significantly different than measurements taken after the liposuction procedures. Conclusions The liposuction procedure does not significantly alter the perfusion of perforator-based abdominal flaps in the early period. The abdominal tissue discarded in a classic abdominoplasty operation can be raised as a perforator flap and has been demonstrated to be a unique model for clinical research.

Evaluation of Plastic Anisotropy in the Steel Sheets Using EMAT (EMAT를 이용한 판재의 소성이방성 평가)

  • Ahn, B.Y.;Kim, Y.G.;Lee, S.S.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.17 no.4
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    • pp.270-277
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    • 1997
  • Plastic anisotropy is one of important factors which determine the drawability of a steel sheet. It has been mainly measured by mechanical tensile test. From the ultrasonic velocities propagating along the relative directions to the rolling direction, CODF(crystallite orientation distribution function) can be measured and ODC's(orientation distribution coefficients) has some correlations with the plastic anisotropy. In this study the correlations between the plastic anisotropy and ODC's of the cold rolled steel sheet were measured. From the results of ultrasonic velocity measurements the average normal anisotropy, $\bar{\gamma}$ and the average planar anisotropy, ${\Delta}r$ could be predicted within the accuracy of ${\pm}0.082$ and ${\pm}0.096$, respectively. Acoustic resonance method was applied to measure the ultrasonic velocities and EMAT's were used for generating and detecting the ultrasonic waves.

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Predictive Value of the Platelet-To-Lymphocyte Ratio in Diagnosis of Prostate Cancer

  • Yuksel, Ozgur Haki;Urkmez, Ahmet;Akan, Serkan;Yldirim, Caglar;Verit, Ayhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6407-6412
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    • 2015
  • Purpose: To predict prostatic carcinoma using a logistic regression model on prebiopsy peripheral blood samples. Materials and Methods: Data of a total of 873 patients who consulted Urology Outpatient Clinics of Fatih Sultan Mehmet Training and Research Hospital between February 2008 and April 2014 scheduled for prostate biopsy were screened retrospectively. PSA levels, prostate volumes, prebiopsy whole blood cell counts, neutrophil and platelet counts, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), biopsy results and Gleason scores in patients who had established diagnosis of prostate cancer (PCa) were evaluated. Results: This study was performed on a total of 873 cases, with an age range 48-76 years, divided into three groups as for biopsy results. with diagnoses of benign prostatic hyperplasia (BPH) (n=304, 34.8 %), PCa (n=265, 30.4 %) and histological prostatitis (n=304; 34.8 %). Intra- and intergroup comparative evaluations were performed. White blood cell and neutrophil counts in the histological prostatitis group were significantly higher than those of the BPH and PCa groups (p=0.001; p=0.004; p<0.01). A statistically significant intergroup difference was found for PLR (p=0.041; p<0.05) but not lymphocyte count (p>0.05). According to pairwise comparisons, PLR were significantly higher in the PCa group relative to BPH group (p=0.018, p<0.05, respectively). Though not statistically significant, higher PLR in cases with PCa in comparison with the prostatitis group was remarkable (p=0.067, and p>0.05, respectively). Conclusions: Meta-analyses showed that in patients with PSA levels over 4 ng/ml, positive predictive value of PSA is only 25 percent. Therefore, novel markers which can both detect clinically significant prostate cancer, and also prevent unnecessary biopsies are needed. Relevant to this issue in addition to PSA density, velocity, and PCA3, various markers have been analyzed. In the present study, PLR were found to be the additional predictor of prostatic carcinoma.

Experimental result of Real-time Sonar-based SLAM for underwater robot (소나 기반 수중 로봇의 실시간 위치 추정 및 지도 작성에 대한 실험적 검증)

  • Lee, Yeongjun;Choi, Jinwoo;Ko, Nak Yong;Kim, Taejin;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.3
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    • pp.108-118
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    • 2017
  • This paper presents experimental results of realtime sonar-based SLAM (simultaneous localization and mapping) using probability-based landmark-recognition. The sonar-based SLAM is used for navigation of underwater robot. Inertial sensor as IMU (Inertial Measurement Unit) and DVL (Doppler Velocity Log) and external information from sonar image processing are fused by Extended Kalman Filter (EKF) technique to get the navigation information. The vehicle location is estimated by inertial sensor data, and it is corrected by sonar data which provides relative position between the vehicle and the landmark on the bottom of the basin. For the verification of the proposed method, the experiments were performed in a basin environment using an underwater robot, yShark.

Prediction and Experiment of Pressure Drop of R22, R407C and R410A on Design Conditions of Condenser (응축기의 설계조건에서 R22, R407C, R410A의 압력강하 예측 및 실험)

  • 김창덕;박일환;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.1
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    • pp.42-53
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    • 2004
  • An experimental study on the refrigerant-side pressure drop of slit fin-tube heat exchanger has been carried out. A comparison was made between the predictions of previously proposed empirical correlations and experimental data for the pressure drop on design conditions of condenser in micro-fin tube for R22 and its alternatives, R407C (R32/125/134a, 23/25/52 wt.%) and R410A (R32/125, 50/50 wt.%). Experiments were carried out under the conditions of inlet refrigerant temperature of 6$0^{\circ}C$ and mass fluxes varying from 150 to 250 kg/$m^2$s for R22, R407C and R410A. The inlet air conditions are dry bulb temperature of 35$^{\circ}C$, relative humidity of 40% and air velocity varying from 0.68 to 1.43 m/s. Experiments show that pressure drop for R410A and R407C were 17.8∼20.2% and 5∼6.8% lower than those of R22 respectively for the degree of subcooling of 5$^{\circ}C$. For the mass fluxes of 200∼250 kg/$m^2$s, the deviation between the experimental and predicted values for the pressure drop was less than $\pm$20% for R22, R407C and R410A.

Thermal Properties on combination of Velvet and Lining (벨벳과 안감의 소재 조합에 따른 의복의 열저항에 관한 연구)

  • 계명대학교의류학과;이욱자;류덕환
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.1
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    • pp.3-13
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    • 1999
  • This study was performed for purpose of getting fundamental information requisite to wear velvet clothes that is more comfortable for the human body and also the environment. It was carried out in a human wearing test and thermal manikin test at the same time in a controlled-condition chamber. The experimental environment had a ambient temperature of 15$\pm$0.5$^{\circ}C$ with the relative humidity at 5$^{\circ}C$$\pm$5% and with air velocity at less that than 0.2m/sec. Velvet differ from common plain weaves in thermal properties because it's constructed in two parts one is ground part and the other part is pile part. In order to investigate the thermal resistance of velvet eight different combination of 4 velvet kinds and 2 lings kinds as experimental clothes. [(4 velvet kinds : Acetate cuprammoium Rayon Cotton Wool) (2 lining kinds : acetate viscose rayon)longrightarrow8 combination: Aa, Av, Ra, Rv, Ca, Cv, Wa, Wv: the simplified character] The results of this study can be summarized as follows : 1. For the regional thermal resistance the differences in eight clothes as well as differences in each part were significant. As a whole the breast part showed the highest thermal resistance and the leg part was higher than the shank part. The rank of the total thermal resistance was put at Wa>Wv>Ca>Cv>Aa>Av>Ra>Rv in this order. 2. Considered clothing microclimate microclimate temperature has a similar tendency to the total thermal resistance. It showed a significance in the differences of eight clothes and each parts. the belly part was highest in every combination. On the other hand for clothing humidity there was a significance between back and breast part only in the human wearing test. 3. It was indicated that CLO value was highly positively correlated with the clothings' weight and showed a high negative correlation with the air permeability.

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Collapse Behavior of Small-Scaled RC Structures Using Felling Method (전도공법에 의한 축소모형 철근콘크리트 구조물의 붕괴거동)

  • Park, Hoon;Lee, Hee-Gwang;Yoo, Ji-Wan;Song, Jeung-Un;Kim, Seung-Kon
    • Tunnel and Underground Space
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    • v.17 no.5
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    • pp.381-388
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    • 2007
  • The regular RC structures have been transformed into irregular RC structures by alternate load of RC structures during explosive demolition. Numerical simulation programs have contributed to a better understanding of large displacement collapse behavior during explosive demolition, but there remain a number of problems which need to be solved. In this study, the 1/5 scaled 1, 3 and 5 stories RC structures were designed and fabricated. To consider the collapse possibility of upper dead load, fabricated RC structures were demolished by means of felling method. To observe the collapse behavior of the RC structures during felling, displacement of X-direction (or horizontal), displacement of Z-direction (or vertical) md relative displacement angle from respective RC structures were analyzed. Finally explosive demolition on the scaled RC structures using felling method are carried out, collapse behavior by felling method is affected by upper dead load of scaled RC structures. Displacement of X and Z direction increases gradually to respective 67ms and 300ms after blasting. It is confirmed that initial collapse velocity due to alternate load has a higher 3 stories RC structures than 5 stories.

Effect of load on the wear and friction characteristics of a carbon fiber composites (탄소 섬유 복합재의 마찰 및 마모 특성에 미치는 하중 효과)

  • Koh, Sung-Wi;Yang, Byeong-Chun;Kim, Hyung-Jin;Kim, Jae-Dong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.40 no.4
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    • pp.344-350
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    • 2004
  • This is the study on dry sliding wear behavior of unidirectional carbon fiber reinforced epoxy matrix composite at ambient temperature. The wear rates and friction coefficients against the stainless steel counterpart specularly processed were experimentally determined and the resulting wear mechanisms were microscopically observed. Three principal sliding directions relative to the dominant fiber orientation in the composite wear selected. When sliding took place against smooth and hard counterpart, the highest were resistance and the lowest friction coefficient were observed in the antiparallel direction. When the velocity between the composite and the counterpart went up, the wear rate increased. The fiber destruction and cracking caused fiber bending on the contact surface, which was discovered to be dominant wear mechanism.

SPECTROSCOPIC AND PHOTOMETRIC STUDY OF STARBURST GALAXIES: OPTICAL AND NEAR INFRARED PROPERTIES OF A BLUE COMPACT DWARF GALAXY MRK 49 IN THE VIRGO CLUSTER

  • Sung, Eon-Chang;Kyeong, Jae-Mann;Byun, Yong-Ik
    • Journal of The Korean Astronomical Society
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    • v.41 no.5
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    • pp.121-137
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    • 2008
  • We present optical and near-infrared imaging and long-slit spectroscopy for the blue compact dwarf galaxy (BCD) Mrk 49 in the Virgo Cluster. The surface brightness distribution analysis shows that Mrk 49 consists of an off-centered blue bright compact core of r = 10" and a red faint outer exponential envelope. The $H_{\alpha}$ image and color difference suggest that these two components have different stellar populations: a high surface brightness population of massive young stars and an underlying low surface brightness population of older stars. The redder near-infrared colors of the inner most region suggest that the near-infrared flux of Mrk 49 originates from evolved massive stars associated with the current star-forming activity. The total apparent magnitude is $B_T\;=\;14.32$ mag and the mean effective surface brightness is ${\mu}_{eff}(B)\;=\;21.56$ mag $arcsec^{-2}$. Long-slit spectroscopy shows that Mrk 49 rotates apparently as a solid body within r = 10" in a plane at position angle 55 degrees with an amplitude of about $20\;km\;sec^{-1}$. The measured radial velocity of Mrk 49 was derived as $1,535\;km\;sec^{-1}$; and the total mass of stars and gases is in the range of 3 to $6\;{\times}\;10^9\;M_{\odot}$. The mass-to-light ratios for the central region of Mrk 49 in I and B band are estimated 1.0 and 0.5, respectively. The upper limit of the dark matter to visible matter ratio seems to be < 5. The oxygen abundance is $12\;+\;\log(O/H)\;=\;8.21\;{\pm}\; 0.1$ which is about one quarter of the solar value while the relative helium abundance appears to be similar to that of the sun.