• Title/Summary/Keyword: Pre-ventilation

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Biodrying of municipal solid waste under different ventilation periods

  • Ab Jalil, N.A.;Basri, H.;Basri, N.E. Ahmad;Abushammala, Mohammed F.M.
    • Environmental Engineering Research
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    • v.21 no.2
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    • pp.145-151
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    • 2016
  • Biodrying is a pre-treatment method that applies biological and mechanical concepts to drying solid waste. In Malaysia, municipal solid waste (MSW) is unseparated and contains a high level of moisture, making the use of technology such as solid waste burning unsuitable and harmful. MSW containing organic material can be processed naturally until the moisture content of the waste is reduced. This study on MSW biodrying was carried out on a laboratory scale to measure the percent moisture content reduction and to monitor temperature patterns under different ventilation periods. This work was conducted using five biodrying reactors volumes of 50 liters each. Reactors were ventilated for 5, 10, 15, 20 and 30 min every 3 h, with a 3 bar air supply. The duration of this process was 14 days for all samples. The results showed that the optimum ventilation time was 10 min, with an 81.84% reduction in moisture content, and that it required almost half of the electricity cost required for the 20 and 30 min ventilations.

In-transit development of color abnormalities in turkey breast meat during winter season

  • Carvalho, Rafael H.;Honorato, Danielle C.B.;Guarnieri, Paulo D.;Soares, Adriana L.;Pedrao, Mayka R.;Oba, Alexandre;Paiao, Fernanda G.;Ida, Elza I.;Shimokomaki, Massami
    • Journal of Animal Science and Technology
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    • v.60 no.1
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    • pp.30.1-30.10
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    • 2018
  • Background: The poultry industry suffers losses from problems as pale, soft and exudative (PSE), and dark, firm and dry (DFD) meat can develop in meat as a result of short- and long-term stress, respectively. These abnormalities are impacted by pre-slaughter animal welfare. Methods: This work evaluated the effects of open vehicle container microclimate, throughout the $38{\pm}10km$ journey from the farm to the slaughterhouse, on commercially turkey transported during the Brazilian winter season. The journey was initiated immediately after water bath in truck fitted with portable Kestrel anemometers to measure air ventilation, relative humidity, temperature and ventilation. Results: The inferior compartments of the middle and rear truck regions showed highest temperature and relative humidity, and lower air ventilation. In addition, the superior compartments of the front truck regions presented lower temperature and wind chill, and highest air ventilation. The breast meat samples from animals located at the inferior compartments of the middle and rear truck regions and subjected to with water bath (WiB) treatment presented highest DFD-like and had lowest PSE-like meat incidence than those from animals located at other compartments within the container. Lower incidence of PSE-like meat was observed in birds without water bath (WoB). Conclusions: Assessment on turkeys transported under Brazilian southern winter conditions revealed that breast meat quality can be affected by relative humidity, air ventilation, temperature, and transport under subtropical conditions promoting color abnormalities and the formation of simultaneously PSE-like and DFD-like meat.

Numerical Analysis of Axial-Flow Cyclone Separator for Subway Station HVAC System Pre-Filter

  • Kim, Myung-Joon;Kim, Ho-Joong;Kwon, Soon-Bark;Kim, Se-Young;Kim, Jin-Kwan;Shin, Chang-Hun;Bae, Sung-Joon;Hwang, Sun-Ho;Kim, Tae-Sung
    • International Journal of Air-Conditioning and Refrigeration
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    • v.17 no.3
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    • pp.94-99
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    • 2009
  • In the Korean subway station, three types of pre-filters, which include auto filter, electrostatic precipitator (ESP) and auto cleaning demister, are widely used. However, these devices have some problems such as the difficulty of maintenance and high operating cost. In this study, axial-flow cyclone separator was employed as a pre-filter inside a heating, ventilation, and air conditioning (HVAC) system. 3-dimensional computational fluid dynamics (CFD) analysis was performed on a single unit axial-flow cyclone and coupled unit axial-flow cyclone. Calculated and measured pressure drop of the designed axial-flow cyclone were found be comparable to other types of pre-filters and the observed cut-off diameter was less than 10 micron. Considering lower operating and maintenance cost, axial-flow cyclone was proved to be a better solution as a pre-filter.

Pulmonary Function Following Open Heart Surgery -early and late postoperative changes- (개심술후 폐기능 -수술직후 및 장기간의 추이에 대하여-)

  • 이성행
    • Journal of Chest Surgery
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    • v.13 no.4
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    • pp.364-374
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    • 1980
  • Twenty-two patients were selected for evaluation of pre-and postoperative pulmonary function. These patients were performed open cardiac surgery with the extracorporeal circulation from March 1979 to July 1980 at the Department of Thoracic and Cardiovascular Surgery, Kyungbook National University Hospital. Patients were classified with ventricular septal defect 5 cases, atrial septal defect 5 cases, tetralogy of Fallot 5 cases, mitral stenosis 4 cases, rupture of aneurysm of sinus Valsalva 1 case, left atrial myxoma I case, and aortic insufficiency 1 case. The pulmonary function tests were performed and listed: [1] respiratory rate, tidal volume [TV], and minute volume[MV], [2] forced vital capacity [FVC] and forced expiratory volume[FEV 0.5 & FEV 1.0], [3] forced expiratory flow [FEF 200-1200 ml & FEF 25-75%]. [4] Maximal voluntary ventilation [MVV], [5] residual volume [RV] and functional residual capacity[FRC], measured by a helium dilution technique. Respiratory rate increased during the early postoperative days and tidal volume decreased significantly. These values returned to the preoperative levels after postoperative 5-6 days. Minute volume decreased slightly, but essentially unchanged. Preoperative mean values of the forced vital capacity, functional residual capacity and total lung capacity decreased [63.2%, 87.2% & 77.3% predicted, respectively], and early postoperatively these values decreased further [19.6%, 76.0% & 38.0% predicted], but later progressively increased to the preoperative levels. In residual volume, there was no decline in the preoperative mean values [100.9% predicted] and postoperatively the value rather increased [106.3-161.7% predicted]. Forced expiratory volume [FEV 0.5 & FEV 1.0] and forced expiratory flow [FEF 200-1200 ml & FEF 25-75%] also revealed significant declines in the early postoperative period. There was no significant difference in values of the spirometric pulmonary function tests, such as FEF 1.O and FEF 25-75% between successful weaning group [17 cases] extubated within 24 hrs post-operatively and unsuccessful weaning group [5 cases] extubated beyond 24 hrs. Static compliance and airway resistance measured for the two cases during assisted ventilation, however, any information was not obtained. Long term follow-up pulmonary function studies were carried out for 8 cases in 9 months post-operatively. All of the results returned to the pre-operative or to normal predicted levels except FVC, FEV 1.0, and FEF 25-75% those showed minimal declines compared to the pre-operative figures.

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A Study on Stabilization of Landfill by Air Ventilation in Field (공기주입방식을 통한 쓰레기 안정화의 현장적용에 관한 연구)

  • Lee, Hwan;Lee, Chae-young;Jeon, Yeon-ho;Kim, Kyung;Kim, Doo-il;Lee, Cheol-hyo
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.4
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    • pp.121-128
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    • 2000
  • Landfill and lysimeter experiments were conducted to estimate the optimum air injection method for the degradation of waste in landfill and the pre-stabilization. Continuous injection with low pressure and quantity can be effective for pre-stabilization of old landfill due to the lower contents of volatile solids in landfill. Air injection and landfill gas (LFG)extraction showed that the SVE (Soil Vapor Extraction) effect by air ventilation was more significant than the biodegradation of organics. Theses results suggested that they could accelerate the biological stabilization of organic waste in landfills. It is also expected that they would reduce the problems including gas emission during the landfill mining, separation and/or transportation to such levels that might be discharged directly to the atmosphere or with minimal treatment, if required.

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A Study on the Odor and Ventilation in Sludge Incineration Facilities (슬러지 소각시설 악취 및 환기에 관한 연구)

  • Seo, Byung-Suk;Jeon, Yong-Han
    • Journal of the Korea Safety Management & Science
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    • v.22 no.2
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    • pp.7-13
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    • 2020
  • Sludge incineration facilities are socially recognized as a hate facility. Therefore, a careful deodorization plan must be established. Therefore, the incineration facility must conduct research on odor ventilation. In this study, a odor diffusion simulation in an incineration facility was conducted and analyzed. In particular, research was carried out on carry-in rooms, pre-treatment rooms, and storage facilities for crops, which are expected to rapidly spread odor. As a result, ammonia 1.62, hydrogen sulfide 0.63, and acetaldehyde 0.73 were found in the transfer room. In addition, pretreatment rooms and stencil storage facilities were found to be lower than regulatory standards.

Analysis of Flow Characteristics of Forced Ventilated Pre-drying Facility for Mandarin (강제 통풍식 감귤 예건시설의 유동 해석)

  • Kwon, Jin-Kyung;Yun, Hong-Sun;Jeong, Hoon;Lee, Hyun-Dong;Lee, Sung-Hyoun;Moon, Jong-Pil
    • Journal of Biosystems Engineering
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    • v.35 no.6
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    • pp.393-400
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    • 2010
  • Uniform and rapid pre-drying of mandarin is important to improve the storage quality. The aim of this study was to suggest the basic design of forced ventilated pre-drying facility for mandarin by thermal flow analysis using computational fluid dynamics software (FLUENT 6.2). Developed CFD simulation model was verified by comparison with experimental data. Airflows and temperature distributions in the five conceptional designs including existing ordinary temperature storage rooms were analyzed and appropriate basic design was determined. Analysis of the effect of arrangement of windows and exhaust fans on thermal flow in facility was carried out for more detailed design. The results of this investigation showed that the predicted airflow velocity by CFD simulation showed a good agreement with the measured value and optimum design condition for simulated forced ventilated pre-drying facility of mandarin has two exhaust fans and two windows on both sidewalls and cover on loaded mandarin.

Preoperative Levels of Hematological and Biochemical Indices Affect Perioperative Variables in Adult Patients with Coronary Artery Bypass Graft Surgery

  • Choi, Seok-Cheol;Cho, Byung-Kyu;Lee, Yong-Hwan;Chang, Kyung-Soo
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.247-258
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    • 2010
  • The objective of this research was to evaluate the relationships of preoperative (Pre-OP) levels of hematological and biochemical indices to perioperative variables in patients that underwent coronary artery bypass graft surgery (CABG). Pre-OP levels of hematological factors [total white blood cells (T-WBC), erythrocytes, hemoglobin, hematocrit, glycohemoglobin A1c (HbA1c), or platelet] were negatively or positively related with biochemical indices [alanine aminotransferase (ALT), bilirubin, glucose, fructosamine, triglyceride, and high density lipoprotein cholesterol (HDL)]. Pre-OP levels of hematological factors and biochemical indices were negatively or positively correlated with echocardiographic variables. Pre-OP level of HbA1c had a relationship with C-reactive protein. Pre-OP levels of aspartate aminotransferase (AST), ALT, HDL, glucose, fructosamine, or blood urea nitrogen (BUN) were positively or negatively associated with Pre-OP levels of cardiac markers (brain natriuretic peptide, troponin-I, creatine kinase isoenzyme 2, or CRP). Pre-OP levels of hematological factors (excepting T-WBC) related with operation time (OPT), postoperative mechanical ventilation time (POMVT), intensive care unit-period (ICU-period) or hospitalization. Pre-OP levels of AST, ALT, bilirubin, triglyceride, HDL, low dwensity lipoprotein, fructosamine, or BUN were positively or negatively correlated with OPT, graft numbers, POMVT, ICU-period or hospitalization. Retrospective this study reveals that Pre-OP levels of hematological and biochemical markers are associated with echocardiographic variables, several cardiac markers and postoperative outcomes, suggesting that Pre-OP levels of hematological and biochemical markers may be useful predictors for the diagnosis and prognosis of coronary artery disease.

Pulmonary and Cutaneous Evaporative Water Losses in Sahiwal and Sahiwal × Holstein Cattle During Solar Exposure

  • Aggarwal, Anjuli;Upadhyay, R.C.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.3
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    • pp.318-323
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    • 1997
  • In order to assess the effect of solar exposure on pulmonary functions and evaporative losses from skin and pulmonary surfaces, in six healthy Sahiwal (S) and six Sahiwal ${\times}$ Holstein ($S{\times}H$) cattle were exposed to direct sun during summer. Breed differences were observed during exposure. Increase in sweating rate was higher in crossbreds (222%) than in Sahiwal (125%). Pre-exposure (ambient temperature, $32.6{\pm}0.85^\circ}C$, solar radiation, $0.9cal\;cm^{-2}min^{-1}$) evaporative loss from skin accounted for about 90% of the losses and remaining losses were contributed by pulmonary surfaces in Sahiwal. The contribution of evaporation through skin increased to 92% (ambient temperature $39.4{\pm}0.68^\circ}C$, solar radiation, $1.35cal\;cm^{-2}min^{-1}$). In crossbreds 80% of the evaporative losses were through skin before exposure which increased to 87% after exposure to solar radiations. Rectal temperature increase was higher in crossbreds ($1.5^{\circ}C$) than in Sahiwal ($0.8^{\circ}C$). With the increase in pulmonary evaporative losses, respiratory frequency increased to 2 fold in Sahiwal and pulmonary ventilation increased 1.6 times the resting value in Sahiwal due to solar exposure. In $S{\times}H$ crossbreds the respiratory frequency increased 3.5 times and pulmonary ventilation increased only to 1.8 times due to decrease in tidal volume. There was about 2 fold increase in alveolar ventilation in both the breeds, the increase in dead space ventilation was more in crossbreds than in Sahiwal. Behavioral symptoms exhibited by animals after exposure were profuse salivation, open mouth panting, tongue protrusion and general restlessness.

Cooling Control of Greenhouse Using Roof Window Ventilation by Simple Fuzzy Algorithm (단순 퍼지 제어기법을 이용한 온실의 천창환기에 의한 냉방제어)

  • Min, Young-Bong;Yoon, Yong-Cheol;Huh, Moo-Ryong;Kang, Dong-Hyun;Kim, Hyeon-Tae
    • Journal of agriculture & life science
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    • v.44 no.4
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    • pp.69-77
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    • 2010
  • Fuzzy control is widely used for improving temperature control performance as controlling ventilation in greenhouse because the technique can respond more flexibly to the outside air temperature and wind speed. By pre-studied PID and normal fuzzy control this study was performed to obtain the fundamental data that can be established in better greenhouse ventilation control method. The temperature control error by the simple fuzzy control was $1.2^{\circ}C$. The accumulated operating size of the window and the number of operating were 84% and 13, respectively. These showed equivalent control performance with pre-studied result that control error. The accumulated operating size of the window and the number of operating were 75% and 12, respectively. The proposed fuzzy technique was simple control logic method compared with step and PID control methods, but it showed equivalent performance. Therefore, the proposed simple fuzzy control method could be used in micro controller of small programmable memory size and many applications.