• Title/Summary/Keyword: Fluid Management

Search Result 513, Processing Time 0.024 seconds

A Numerical Study on Flow-Accelerated Corrosion in Two Adjacent Elbows

  • Yun, Hun;Hwang, Kyeongmo;Moon, Seung-Jae
    • Corrosion Science and Technology
    • /
    • v.15 no.1
    • /
    • pp.6-12
    • /
    • 2016
  • Flow-Accelerated Corrosion (FAC) is a well-known degradation mechanism that attacks the secondary piping in nuclear power plants. Since the Surry Unit 2 event in 1986, most nuclear power plants have implemented management programs to deal with damages in carbon and low-alloy steel piping. Despite the utmost efforts, damage induced by FAC still occurs in power plants around the world. In order to predict FAC wear, some computer programs were developed such as CHECWORKS, CICERO, and COMSY. Various data need to be input to these programs; the chemical composition of secondary piping, flow operating conditions and piping geometries. CHECWORKS, developed by the Electric Power Research Institute (EPRI), uses a geometry code to calculate geometry effects. Such a relatively simple geometry code is limited in acquiring the accuracy of FAC prediction. Recently, EPRI revisited the geometry code with the intention of updating it. In this study, numerical simulations were performed for two adjacent $90^{\circ}$ elbows and the results were analysed in terms of the proximity effect between the two adjacent elbows.

Desktop PC CPU Cooling System Design and Analysis

  • Choi, Jee-Hoon;Yoo, Jung-Hyun;Seo, Min-Whan;Kang, Shin-Jae;Kim, Chul-Ju
    • Proceedings of the SAREK Conference
    • /
    • 2008.11a
    • /
    • pp.601-604
    • /
    • 2008
  • Desktop PC CPUs have been significantly required to be the necessity of thermal management while they have satisfied the extensive data and graphic processing requirements. So the cooling systems assembled with heat pipes embedded in a metal cooling plate, and fins are widely used in the desktop PC markets. Due to a number of demands such as the confined space of desktop PCs, higher heat density of CPUs, and acoustic noise, however, there is the main drive to improve continuously cooling systems. This paper presents the flow and thermal behavior of the cooling system by using the computational fluid dynamics(CFD) code.

  • PDF

Case report of the management of the ranula

  • Choi, Moon-Gi
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.45 no.6
    • /
    • pp.357-363
    • /
    • 2019
  • Ranula is a mucocele caused by extravasation of the sublingual gland on the floor of the mouth. The most common presentation is a cystic mass in the floor of the mouth. A portion of the sublingual gland could herniate through the mylohyoid muscle, and its extravasated mucin can spread along this hiatus into submandibular and submental spaces and cause cervical swelling. This phenomenon is called plunging ranula. A variety of treatments for ranula has been suggested and include aspiration of cystic fluid, sclerotherapy, marsupialization, incision and drainage, ranula excision only, and excision of the sublingual gland with or without ranula. Those various treatments have shown diverse results. Most surgeons agree that removal of the sublingual gland is necessary in oral and plunging ranula. Four patients with ranula were investigated retrospectively, and treatment methods based on literature review were attempted.

A Methodology for Determination of the Safety Distance in Chemical Plants using CFD Modeling (CFD 모델링을 이용한 화학공장의 안전거리 산정 방법론에 관한 연구)

  • Baek, Ju-Hong;Lee, Hyang-Jig;Jang, Chang Bong
    • Journal of the Korean Society of Safety
    • /
    • v.31 no.3
    • /
    • pp.162-167
    • /
    • 2016
  • As the simple empirical and phenomenological model applied to the analysis of leakage and explosion of chemical substances does not regard numerous variables, such as positional density of installations and equipment, turbulence, atmospheric conditions, obstacles, and wind effects, there is a significant gap between actual accident consequence and computation. Therefore, the risk management of a chemical plant based on such a computation surely has low reliability. Since a process plant is required to have outcomes more similar to the actual outcomes to secure highly reliable safety, this study was designed to apply the CFD (computational fluid dynamics) simulation technique to analyze a virtual prediction under numerous variables of leakages and explosions very similarly to reality, in order to review the computation technique of the practical safety distance at a process plant.

The Effectiveness of Noninvasive Positive Pressure Ventilation in Subarachnoid Pleural Fistula: A Case Report and Literature Review

  • Soundararajan, Dilip Chand Raja;Shetty, Ajoy Prasad;Kanna, Rishi Mugesh;Rajasekaran, S.
    • Neurospine
    • /
    • v.15 no.4
    • /
    • pp.394-399
    • /
    • 2018
  • Subarachnoid pleural fistula (SPF) is an aberrant communication between the pleural cavity and subarachnoid space, resulting in uncontrolled cerebrospinal fluid drainage. The negative pressure of the pleural cavity creates a continuous suctioning effect, thereby impeding the spontaneous closure of these fistulas. Dural tears or punctures in cardiothoracic procedures, spinal operations, and trauma are known to cause such abnormal communications. Failure to recognize this entity may result in sudden neurological or respiratory complications. Hence, a high index of suspicion is required for early diagnosis and prompt management. Noninvasive positive pressure ventilation has been described to be effective in managing such fistulas, thus mitigating the high morbidity associated with exploratory surgery for primary repair. Herein, we describe the typical presentation of SPF and the clinical course, treatment, and follow-up of a patient who sustained SPF following anterior thoracic spinal surgery.

Rapid Spontaneous Resolution of Contralateral Acute Subdural Hemorrhage Caused by Overdrainage of Chronic Subdural Hemorrhage

  • Yoo, Minwook;Kim, Jung-Soo
    • Journal of Neurocritical Care
    • /
    • v.11 no.2
    • /
    • pp.119-123
    • /
    • 2018
  • Background: Since the first report of a rapidly resolved subdural hemorrhage (SDH) in 1986, few additional case reports have been presented in the literature. Case Report: An 82-year-old female patient presented with a SDH over the left convexity. The SDH was removed via catheter drainage through a burr hole trephination. Post-operative computed tomography (CT) following 300 mL drainage from the chronic SDH demonstrated a newly developed SDH along the right convexity. A follow-up CT performed 2 hours later revealed an unexpected significant resolution of the acute SDH. Conclusion: The spontaneous resolution of acute SDH is believed to result from redistribution by washout of the hematoma by cerebrospinal fluid dilution. However, its exact pathophysiology is not well understood. When surgical evacuation is considered in acute SDH, conservative management should also be considered because spontaneous resolution of hemorrhage remains a possibility.

Surgical Management and Long-Term Follow-Up of a Giant Hepatic Cyst with an Internal Septum in a Cat

  • Kim, Kihoon;Kim, Hyungjoon;Eom, Ki-Dong;Kim, Hwi-Yool
    • Journal of Veterinary Clinics
    • /
    • v.38 no.6
    • /
    • pp.295-298
    • /
    • 2021
  • A 1-year-old spayed female Scottish Fold cat presented with a 1.5-month history of vomiting, intermittent dyspnea, and abdominal distention. Radiographic, ultrasonographic, and computed tomographic examinations suggested a tentative diagnosis of a fluid-containing cystic mass with an internal septum. The mass was surgically removed. Histological examinations revealed that the mass was a non-neoplastic hepatic cyst. The patient had no recurrence of the cystic structure but died of acute renal failure 5 years after the surgery. This report describes the unusual case of a giant hepatic cyst with clinical signs that resolved after mass removal.

Permanent Surgical Treatment for Posthemorrhagic Hydrocephalus in Preterm Infants

  • Atsuko Harada
    • Journal of Korean Neurosurgical Society
    • /
    • v.66 no.3
    • /
    • pp.281-288
    • /
    • 2023
  • While the standard management for posthemorrhagic hydrocephalus (PHH) has not been determined, many patients initially receive temporary treatment such as a ventricular drainage, a ventricular reservoir, or a ventriculosubgaleal shunt. Subsequently, approximately 15% of patients with PHH will require permanent cerebrospinal fluid diversion. Shunt placement is most commonly performed for PHH as permanent treatment. However, shunting still has high complication rates. Since the development of the neuroendoscopic technique has progressed, and indication has been expanded, endoscopic third ventriculostomy with or without choroid plexus cauterization has performed more frequently in recent years in patients with PHH. In this paper, the permanent treatment for PHH will be reviewed based on the latest evidence.

Technological Trends in Safety Solutions for Construction Equipment (건설장비의 안전 솔루션 기술 동향)

  • Yong Jin Kim;Myoung Kook Seo
    • Journal of Drive and Control
    • /
    • v.20 no.2
    • /
    • pp.7-14
    • /
    • 2023
  • Negative perceptions of the construction industry are prevalent due to the high accident rate at construction sites. Recently, with the gradual change of the perception in industrial safety, the demand for improving the safety level of construction sites has increased. Accordingly, the government is preparing various safety-level measures such as the Serious Disaster Punishment Act and support for industrial safety management costs. In addition, private industries are incorporating various safety equipment in the sites. This paper introduced the current status of safety sensors and solutions currently applied to construction equipment and industrial vehicles. The technology development direction suitable for construction equipment was introduced by comparing the operating environment of automobiles and construction equipment. and the need to develop performance standards to protect and revitalize the market for safety devices for construction equipment was suggested.

Effect of Oral Hygiene Management Process using Natural Gargle Fluid (Cinnamon) on Occlusal Force and Changes in Oral Environment

  • Bo Ram Kim;Kyung Min Kim;Yu mi Kim;Min-Kyoung Park;Min Kyung Lee
    • Biomedical Science Letters
    • /
    • v.30 no.1
    • /
    • pp.17-23
    • /
    • 2024
  • In this study, the changes in occlusal strength and oral environment before and after the use of natural gargles containing cinnamon were confirmed. This study involved 42 adults aged 19 or older living in Busan from November 25 to December 2, 2023. Twenty-one people were randomly selected for each of the regular and natural gargles. In this study, the group using natural gargles confirmed an increase in saliva buffering power, a decrease in O'Leary index, and an increase in occlusal strength. Through this, it was confirmed that natural gargles containing cinnamon are helpful in improving the oral environment and occlusal strength.