876 research outputs found

    Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet

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    [EN] In the present work, we experimentally investigated the effect of initial liquid droplet size on the evaporation in the heterogeneous droplet. Spherical carbon and water were used for particle and liquid droplet comprising the heterogeneous droplet. four initial droplet volumes of 1, 2, 3 and 4 μl were considered when the diameter of the particle was 5 mm. The heterogeneous droplet was suspended with a rod at 20 cm away from the radiator which surface temperature was fixed to 473 K. Ambient temperature and relative humidity remained 296 K and 40 %, respectively, during the experiment. As the results, the evaporation rate of 4 μl case increased about 1.8 times compared with that of 1 μl case. The evaporation rate increased almost linearly with the volume ratio, and that is related closely with the contact surface between particle and water droplet. Contact surface area remained almost constantly with time, whereas it increased with the initial volume of water droplet. The energy from radiator can be accumulated at the contact surface at the side of particle, thereby intensifying the evaporation of water droplet because more heat transfers from particle to droplet through the contact surface. Consequently, the initial volume of liquid droplet is one of the influence factors on the evaporation rate in the heterogenous droplet.This research was supported by the Fire Fighting Safety & 119 Rescue Technology Research and Development Program funded by the Ministry of Public Safety and Security (NEMA-NG-2014-46) and Research Project of Air Sampling Detector funded by Alllitelife co. Inc..Sung, KH.; Nam, JS.; Hong, GB.; Ryou, HS. (2017). Experimental study on the effect of initial liquid droplet size on the evaporation in a heterogeneous droplet. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 290-295. https://doi.org/10.4995/ILASS2017.2017.4744OCS29029

    Effects of Aerobic Exercise Intensity on Post-exercise Blood Pressure and Cardiovascular Function in Prehypertensive Men in Their 30s

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    PURPOSE Blood pressure (BP) in hypertensive individuals is reduced by the accumulation of post-exercise hypotension (PEH) induced by a long period of training. This study aimed to investigate the effects of intensity of two different aerobic exercises with identical energy expenditure on post-exercise blood pressure and cardiovascular function in prehypertensive men. METHODS Eleven prehypertensive men in their 30s participated in two trials repeatedly. In the first trial, the exercise was moderate in intensity and continuous (MICE) with 70% of VO2max, and the exercise in the second trial was high-intensity interval exercise (HIIE) with 50% and 90% of VO2max. Each exercise was performed for 30 min, and the variables related to BP and cardiovascular function were measured at certain times for 1 hr during the recovery phase. RESULTS Our main findings are as follows: (1) Systolic blood pressure was significantly lower at 30 and 45 min of recovery time than the baseline in the HIIE trial, and systolic blood pressure was significantly lower in the HIIE trial than the MICE trial at 10, 15, and 30 min of recovery time. (2) The rate pressure product was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (3) The heart rate was significantly higher in the HIIE trial than the MICE trial at 15, 30, 45, and 60 min of recovery time. (4) Stroke volume was significantly lower in the HIIE trial than the MICE trial at 30 min of recovery time. (5) Cardiac output was significantly higher in the HIIE trial than the MICE trial at 15 min of recovery phase. (6) Total vascular conductance was significantly higher in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. (7) Total peripheral resistance was significantly lower in the HIIE trial than the MICE trial at 15 and 30 min of recovery phase. CONCLUSIONS The HIIE shows a higher cardiovascular stress than MICE; however, HIIE contributes to the augmentation of PEH and improvement of cardiovascular function. Therefore, HIIE rather than MICE should be suggested in BP control and enhancement of cardiovascular function in prehypertensive males

    Estimates of Discharge Coefficient in Levee Breach Under Two Different Approach Flow Types

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    The amount of released water (discharge) in a levee breach is a primary input variable to establish an emergency action plan for the area next to the levee. However, although several studies have been conducted, there is still no widely applicable discharge coefficient formula; this needs to be known to estimate discharge amount through an opening caused by a levee breach. Sometimes, the discharge coefficient developed for a sharp crested side weir is used to rate the discharge, but, in case of a levee breach, the resulting geometry and flow types are similar to that over a broad crested weir. Thus, in this study, two different openings—rectangular and trapezoidal shape—are constructed in the center of a levee at a height of 0.6m to replicate levee breach scenarios, and the effect of two different approach flow types—the river type approach and reservoir type approach—are explored to suggest a discharge coefficient formula applicable for discharge rating for a levee breach. The results show that the ratio of head above the bottom of an opening and the opening width is a key variable for calculating the discharge coefficient of a reservoir type, but the approach Froude number should also be considered for a river type approach. The measured data are used to improve rating equations and will be useful in the future to validate computational fluid dynamics simulations of wave propagation during levee failure into the inundation area

    Tracing the historical origin of Joseon mummies considering the structural similarities between the burial systems of Korean and Chinese dynasties

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    Joseon mummies have proved to be excellent subjects for scientific research on the health and disease statuses of pre-modern Korean peoples. Despite its academic significance, the origins of the Hoegwakmyo tomb in which the Joseon mummy was discovered have not yet been entirely revealed. Meanwhile, over the past several decades, there have been some reports on mummies and cultural artifacts preserved very well in the tombs of several Chinese dynasties (especially Song, Yuan, Ming and Qing). Although the Chinese tombs were very diverse in structure, we note that some graves among them were structurally very similar to Joseon Hoegwakmyo tombs. Before the Hoegwakmyo tomb in Korea, there were already similar tombs in China, inside which dead persons were mummified like the Joseon mummies. Considering that the Hoegwakmyo tomb of the Joseon Dynasty was established by the influence of the Confucian ideology, the Korean and Chinese mummies might share common cultural origins in history

    Draft genome sequence of a caprolactam degrader bacterium: Pseudomonas taiwanensis strain SJ9

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    AbstractPseudomonas taiwanensis strain SJ9 is a caprolactam degrader, isolated from industrial wastewater in South Korea and considered to have the potential for caprolactam bioremediation. The genome of this strain is approximately 6.2 Mb (G+C content, 61.75%) with 6,010 protein-coding sequences (CDS), of which 46% are assigned to recognized functional genes. This draft genome of strain SJ9 will provide insights into the genetic basis of its caprolactam-degradation ability

    Does robot-assisted laparoscopic radical prostatectomy enable to obtain adequate oncological and functional outcomes during the learning curve? From the Korean experience

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    To estimate the short-term results of robot-assisted laparoscopic radical prostatectomy (RALRP) during the learning curve, in terms of surgical, oncological and functional outcomes, we conducted a prospective survey on RALRP. From July 2007, a single surgeon performed 63 robotic prostatectomies using the same operative technique. Perioperative data, including pathological and early functional results of the patient, were collected prospectively and analyzed. Along with the accumulation of the cases, the total operative time, setup time, console time and blood loss were significantly decreased. No major complication was present in any patient. Transfusion was needed in six patients; all of them were within the initial 15 cases. The positive surgical margin rate was 9.8% (5/51) in pT2 disease. The most frequent location of positive margin in this stage was the lateral aspect (60%), but in pT3 disease multiple margins were the most frequent (41.7%). Overall, 53 (84.1%) patients had totally continent status and the median time to continence was 6.56 weeks. Among 17 patients who maintained preoperative sexual activity ( Sexual Health Inventory for Men \u3e = 17), stage below pT2, followed up for \u3e 6 months with minimally one side of neurovascular bundle preservation procedure, 12 (70.6%) were capable of intercourse postoperatively, and the mean time for sexual intercourse after operation was 5.7 months. In this series, robotic prostatectomy was a feasible and reproducible technique, with a short learning curve and low perioperative complication rate. Even during the initial phase of the learning curve, satisfactory results were obtained with regard to functional and oncological outcome

    Two Different Renal Cell Carcinomas and Multiple Angiomyolipomas in a Patient with Tuberous Sclerosis

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    We report a case of tuberous sclerosis associated with two histologically different renal cell carcinomas (RCCs) and multiple angiomyolipomas (AMLs) in the same kidney. A 43-year-old female was admitted to our hospital with left flank pain and a huge palpable mass in the left flank area. Abdominal computed tomography revealed two concurrent RCCs and multiple AMLs in the left kidney. Because of the clinical suspicion of RCC, the patient underwent left radical nephrectomy. On gross examination, the total size of the resected left kidney was 30.5Ă—17Ă—8 cm. Microscopically, the upper pole tumor features were consistent with chromophobe RCC and the midpole tumor was a clear-cell RCC. The multifocal masses in the remaining remnant parenchyma were AMLs. Six months after surgery, the patient is healthy without signs of tumor recurrence
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