• Title/Summary/Keyword: Fluid Management

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EPAR V2.0: AUTOMATED MONITORING AND VISUALIZATION OF POTENTIAL AREAS FOR BUILDING RETROFIT USING THERMAL CAMERAS AND COMPUTATIONAL FLUID DYNAMICS (CFD) MODELS

  • Youngjib Ham;Mani Golparvar-Fard
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.279-286
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    • 2013
  • This paper introduces a new method for identification of building energy performance problems. The presented method is based on automated analysis and visualization of deviations between actual and expected energy performance of the building using EPAR (Energy Performance Augmented Reality) models. For generating EPAR models, during building inspections, energy auditors collect a large number of digital and thermal imagery using a consumer-level single thermal camera that has a built-in digital lens. Based on a pipeline of image-based 3D reconstruction algorithms built on GPU and multi-core CPU architecture, 3D geometrical and thermal point cloud models of the building under inspection are automatically generated and integrated. Then, the resulting actual 3D spatio-thermal model and the expected energy performance model simulated using computational fluid dynamics (CFD) analysis are superimposed within an augmented reality environment. Based on the resulting EPAR models which jointly visualize the actual and expected energy performance of the building under inspection, two new algorithms are introduced for quick and reliable identification of potential performance problems: 1) 3D thermal mesh modeling using k-d trees and nearest neighbor searching to automate calculation of temperature deviations; and 2) automated visualization of performance deviations using a metaphor based on traffic light colors. The proposed EPAR v2.0 modeling method is validated on several interior locations of a residential building and an instructional facility. Our empirical observations show that the automated energy performance analysis using EPAR models enables performance deviations to be rapidly and accurately identified. The visualization of performance deviations in 3D enables auditors to easily identify potential building performance problems. Rather than manually analyzing thermal imagery, auditors can focus on other important tasks such as evaluating possible remedial alternatives.

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Adaptation of Feedlot Cattle to a High-energy Ration by Intraruminal Transplantation of Adapted Ruminal Fluid (제1위내용액 이식에 의한 비육우의 농후사료 적응법에 관한 연구)

  • 이현범;탁연빈;성은주;김기석;이영주;정재석;장종식;권오덕
    • Journal of Veterinary Clinics
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    • v.15 no.1
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    • pp.62-74
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    • 1998
  • In feedlot cattle the abrupt change of diet from roughage to a large quantity of grain for the purpose to improve production often results in increased occurrence of rumen acidosis or acute carbohydrate encouragement enterotoxemia, bloats diarrhea liver abscess and laminitis or robot disease. The common management practice to control these problem is to increase the amount of concentrates in the diet in a stepwise manner until the animals are adapted to a high-grain ration. However this practice requires at least about 3 weeks adaptation period and specially prepared adaptation rations which contain various amount of concentrates. Present experiment was undertaken in order to findout the more simple and rapid adaptation method of cattle to a high grain ration. Nineteen Korean calves aging from four to six month were fed artifical hay (Youngchoun Chuk-Hyup, Korea) which contains 10% of concentrates or alfalfa and rye grass hays for two months and randomly alloted to three experimental groups and two control groups. The experimental group-1 was inoculated by stomach tube for two days with li500 ml/day of ruminal fluid fished from Korean beef cattle that had been previously adapted to a high-energy ration. The experimental group-2 was inoculated by trocalization for two days with the same ruminal fluid. The experimental group-3 was inoculated by trocalization with 1,500 ml/day of bacterial culture which contained 2$\times $10$^{9}$/m1 of Gram-negative bacteria derived from adapted luminal fluid. The two control groups were treated with normal saline solution by the same methods. All animals were fed high-energy ration that contained 80% of grain ad libitum for 30-74 days beginning on the third of the treatment. The effect of the inoculation on the adaptation was observed clinicopathologically with the following results; All of the experimental calves inoculated with the ruminal fluid or Gram-negative bacterial culture derived from adapted cattle did not show any signs of rumen acidosis or other related diseases, while most of the control calves did show diarrhea and bloat and a calf laminitis. The average daily weight gain and feed efficiency of experimental calves were slightly improved compared with control calves. Following the feeding of high-grain rational the pH of the ruminal fluid was lowered in both the experimental and control groups. However severe acidosis with the pH of below 5.0 was observed in only a control group-2. The protozoal number in ruminal fluid was markedly decreased during the high-grain feeding in both the experimental and control calves. However the decrease was mere severe in control calves compared with the experimental calves. The activation of the protozoa were completely disappeared within nine hours at the refrigerator temperature (4"C). No significant differences in heamatological and blood chemical values between the experimental and control calves were recognized. However in one control calf which showed clinically laminitis marked elevations of serum glutamic oxaloacetate transaminase and lactic dehydrogenase activities and a decrease of serum glucose level were observed. From these results it would be concluded the intraruminal transplantation of unadapted calves with the adapted ruminal fluid from cattle previously adapted to a high-energy ration prevents disease problem associated with high-grain feeding and improve weight gain and feed efficiency.ency.

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Output Optimization of Microhydro Kaplan Turbine by Double Regulating Runner and Guide Vane (러너와 가이드 베인의 연동을 통한 마이크로 카프란 수차의 출력 최적화)

  • Park, No-Hyun;Rhee, Young-Woo
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.1
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    • pp.17-23
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    • 2013
  • Recently so much attention has been focused on renewable energy and, since its sources to exploit are already almost saturated in the country, the practical alternative to this situation could be a micro-turbine which uses the low head and low flow. From a point of view of local micro-turbine design capacity and manufacturing technology, the problems such as the accumulation of technical skills, the expansion of related industries, the national policy expansion and the turbine efficiency to improve are still vulnerable and it's true that there are also negative views about the economic feasibility, the technicity and the operation management of the micro-turbine. However, if the improvement can be done in technology of low-head double regulation micro-turbine to generate more outputs and the operation management can be reliably realized, the micro-turbine will be re-evaluated as an appliable source of renewable energy, even the output is small, and by a paradigm shift, it could realize a power generation as an economic and rational system.

A successful conservative management of traumatic thoracic esophageal rupture (흉부둔상에 의한 식도파열의 성공적인 보존적 치료)

  • 노태훈
    • Journal of Chest Surgery
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    • v.21 no.1
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    • pp.169-174
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    • 1988
  • Thoracic esophageal rupture caused by blunt trauma is often not recognized until late because of the vague symptoms in the initial state as well as its rare incidence, which can easily lead to fulminant mediastinitis with frequent fatal outcome. Once extensive mediastinitis occurs, the primary surgical repair of the esophageal tear is considered to be practically impossible. Various methods have been proposed for the management of these desperately ill patients, but no one provides an acceptable good result yet. The purpose of this article is to report the successful result obtained in the treatment of a patient with fulminant mediastinitis from traumatic esophageal rupture by continuous transesophageal irrigation. A 27 year-old male patient was brought to the emergency room of our hospital complaining of dyspnea and chest pain after blunt trauma. The diagnosis of esophageal rupture in the thorax was made late, about 46 hours after the initial injury, when mediastinitis had already progressed. The transesophageal irrigation method was immediately instituted which consisted of profuse transesophageal irrigation of the mediastinum with orally ingested fluid and/or by Levin tube, positioned proximal to the site of the rupture, and drainage of the irrigation fluid by thoracoscopically accurately positioned chest tubes connected to a well suctioning system. With subsiding inflammatory signs and symptoms, the esophagogram, obtained 54 days after the treatment, showed no evidence of the mediastinal leakage of contrast material which contrasted previous esophagograms with definitive dye collections in the mediastinum. Additional endoscopic finding confirmed complete healing of the esophageal mucosa, previously ruptured. He has been followed up without any problem until recently, 6 months after discharge.

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Computational Fluid Dynamics Study on Performance Variation of PEMFC with Serpentine Flow Fields According to Humidity Condition (가습조건이 사형유로를 채택한 고분자 전해질 연료전지의 성능에 미치는 영향에 대한 전산유체역학 해석 연구)

  • Oh, Gyu-Hwan;Lee, Kyu-Jin;Nam, Jin-Hyun;Kim, Charn-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.8
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    • pp.604-612
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    • 2009
  • Water management has been recognized as a crucial factor for achieving better performance and stability in polymer electrolyte membrane fuel cells (PEMFCs). Proper water management should provide favorable water conditions, including the local humidity, membrane water content, and liquid water saturation in PEMFCs, thereby leading to more uniform electrochemical reaction and current generation. In this study, computational fluid dynamics (CFD) simulation was conducted to investigate the effects of the cathode relative humidity (RH) on the performance of a 3 by $3\;cm^2$ PEMFC with serpentine flow fields. The CFD results showed that the best performance of the PEMFC was obtained for the cathode RH of 80%, but the performance variation was small for the cathode RH range of $60{\sim}100%$. However, the loss of the PEMFC performance was significant when the cathode RH was reduced below 40%. The reason for such performance variation was investigated through the detailed inspection of ohmic loss, activation and concentration overpotential, and water and current distributions.

Aseptic Meningitis after a Lumbar Epidural Steroid Injection -A case report- (요부 경막외 스테로이드 주입 후 발생한 무균성 수막염 -증례 보고-)

  • Hwang, Byeong Mun;Leem, Jung Gil
    • The Korean Journal of Pain
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    • v.18 no.1
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    • pp.52-55
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    • 2005
  • Complications following a well conducted epidural steroid injection are rare. A 50-year-old man developed a headache and neck stiffness 2 days after a lumbar epidural steroid injection. Under the impression of aseptic meningitis, fluid and nonsteroidal anti-inflammatory drug therapy was started immediately after cerebrospinal fluid (CSF) sampling. The CSF was turbid, and revealed a white blood cell count, protein, glucose and pressure of $550/{\mu}l$ (98% lymphocyte), 107.9 mg/dl, 48 mg/dl (serum 113 mg/dl) and $17cmH_2O$, respectively. The CSF stain and culture, and antibody test and polymerase chain reaction for pathogens were negative. A computed tomography (CT) scan of the brain revealed no abnormality, and a chest roentgenogram and the results of the neurological examination were normal. Under the impression of aseptic meningitis, the condition was managed conservatively, without antibiotics. Seven days later, the clinical symptoms had improved, and the patient discharged.

A Study on Fluid Identity in Digital Contents (디지털콘텐츠를 위한 플루이드 아이덴티티 연구)

  • Kim, Hak Min
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.9 no.4
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    • pp.201-212
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    • 2013
  • The purpose of this study are to show a new possibility of identity design to be used as tools of users identity expression, designing digital contents by studying on the methods to express users identities successfully in the digital contents design, and to present the possibility to expand the area of identity design. Digital contents are a communication media in it self, but this study tried to consider the digital contents as a tool of users communication or expression. The identity expression, which are not only makes communications efficient but also lets products and companies acknowledged by users, is one of the most indispensable factors in products competitive power in both the present and the future. However, no define methods of identity expression are settled as well as recognized by users properly and accurately yet, so that this study focuses on that point. Therefore, This study is advanced in the direction of establishing the concept of digital identity for an expansion of the media toward the identity expression in design as well as making researchers in successful identity expression ways by means of actual design, more than a graphic image making that simply decorates a digital contents. The point of this study is to show a new concept of identity design that expresses users identities so as to suggest another possibility of identity design.

Study on the application of canvas kite to the fishing gear (캔버스 카이트의 어구 적용에 관한 연구)

  • Bae, Bong-Seong;An, Heui-Chun;Bae, Jae-Hyun;Lee, Ju-Hee;Kwon, Byeong-Guk;Park, Seong-Wook;Jeong, Eui-Cheol
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.4
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    • pp.217-227
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    • 2006
  • This research aims at establishing the application of canvas kite to the fishing gear through the analysis of the lift/drag tests of the kites have been performed in our previous finding. Now that several methodologies were designed to find the most effective triangular model as a buoyancy device applied to the fishing gear. Comparisons of drag/lift were made by installing the model in an installation frame instead of the prototype. Also, we have considered the application of canvas kite to the prototypic fishing gear by calculation using the result of this test. The results obtained from the above approaches are summarized as follows, where attack angle, lift coefficient, maximum lift coefficient and drag coefficient are denoted as $B,\;C_L,\;C_Lmax\;and\;C_D$ respectively. The camber showed a gradual increase with an increase of fluid velocity. There was a big discrepancy in B=20 unlike B=30. Even if the kite retreats along the fluid flow, there is little relationship with the velocity variation. Lifts calculated with the kites were bigger and drags were smaller than those of the calculations with the float only. The kite as the buoyancy device will be very useful when the appropriate applications and the stability are met.

Basic Investigation into the Validity of Thermal Analysis of 18650 Li-ion Battery Pack Using CFD Simulation (CFD 해석을 적용한 18650 리튬-이온 배터리 팩의 열 해석 신뢰도 기초 분석)

  • SIM, CHANG-HWI;KIM, HAN-SANG
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.5
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    • pp.489-497
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    • 2020
  • The Li-ion battery is considered to be one of the potential power sources for electric vehicles. In fact, the efficiency, reliability, and cycle life of Li-ion batteries are highly influenced by their thermal conditions. Therefore, a novel thermal management system is highly required to simultaneously achieve high performance and long life of the battery pack. Basically, thermal modeling is a key issue for the novel thermal management of Li-ion battery systems. In this paper, as a basic study for battery thermal modeling, temperature distributions inside the simple Li-ion battery pack (comprises of nine 18650 Li-ion batteries) under a 1C discharging condition were investigated using measurement and computational fluid dynamics (CFD) simulation approaches. The heat flux boundary conditions of battery cells for the CFD thermal analysis of battery pack were provided by the measurement of single battery cell temperature. The temperature distribution inside the battery pack were compared at six monitoring locations. Results show that the accurate estimation of heat flux at the surface of single cylindrical battery is paramount to the prediction of temperature distributions inside the Li-ion battery under various discharging conditions (C-rates). It is considered that the research approach for the estimation of temperature distribution used in this study can be used as a basic tool to understand the thermal behavior of Li-ion battery pack for the construction of effective battery thermal management systems.

Nonoperative management of colon and mesocolon injuries caused by blunt trauma: three case reports

  • Naa, Lee;Euisung, Jeong;Hyunseok, Jang;Yunchul, Park;Younggoun, Jo;Jungchul, Kim
    • Journal of Trauma and Injury
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    • v.35 no.4
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    • pp.291-296
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    • 2022
  • The therapeutic approach for colon injury has changed continuously with the evolution of management strategies for trauma patients. In general, immediate laparotomy can be considered in hemodynamically unstable patients with positive findings on extended focused assessment with sonography for trauma. However, in the case of hemodynamically stable patients, an additional evaluation like computed tomography (CT) is required. Surgical treatment is often required if prominent mesenteric extravasation, free fluid, bowel infarction, and/or colon wall perforation are observed. However, immediate intervention in hemodynamically stable patients without indications for surgical treatment remains questionable. Three patients with colon and mesocolon injuries caused by blunt trauma were treated by nonoperative management. At the time of admission, they were alert and their vital signs were stable. Colon and mesocolon injuries, large hematoma, colon wall edema, and/or ischemia were revealed on CT. However, no prominent mesenteric extravasation, free fluid, bowel infarction, and/or colon wall perforation were observed. In two cases, conservative treatment was performed without worsening abdominal pain or laboratory tests. Follow-up CT showed improvement without additional treatment. In the third case, follow-up CT and percutaneous drainage were performed in considering the persistent left abdominal discomfort, fever, and elevated inflammatory markers of the patient. After that, outpatient CT showed improvement of the hematoma. In conclusion, nonoperative management can be considered as a therapeutic option for mesocolon and colon injuries caused by blunt trauma of selected cases, despite the presence of large hematoma and ischemia, if there are no clear indications for immediate intervention.