• Title/Summary/Keyword: High Pressure Environment

Search Result 1,011, Processing Time 0.032 seconds

Evaluation of microbiological, cellular and risk factors associated with subclinical mastitis in female buffaloes

  • de Oliveira Moura, Emmanuella;do Nascimento Rangel, Adriano Henrique;de Melo, Maria Celeste Nunes;Borba, Luiz Henrique Fernandes;de Lima, Dorgival Morais Junior;Novaes, Luciano Patto;Urbano, Stela Antas;de Andrade Neto, Julio Cesar
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.30 no.9
    • /
    • pp.1340-1349
    • /
    • 2017
  • Objective: This study aimed to evaluate the microbiological and cellular milk profile for the diagnosis of subclinical mastitis in female buffaloes and to assess risk factors for predisposition of the disease. Methods: Analyses were carried out by standard plate count (SPC), identification of species and antibiotic resistance, somatic cell count (SCC), electrical electrical conductivity of milk (ECM), and lactoferrin content in milk. Teat cups were swabbed to evaluate risk factors, observing hyperkeratosis, milking vacuum pressure and cleanliness of the site. Hence, 30 female buffaloes were randomly selected (15 from a group in early lactation and 15 in late lactation). Results: The most common bacteria in the microbiological examination were Staphylococcus spp., Streptococcus spp. and Corynebacterium sp. In the antibiotic sensitivity test, 10 (58.82%) of the 17 antibiotics tested were sensitive to all isolates, and resistant bacteria were Streptococcus uberis, Streptococcus dysgalactiae, Streptococcus haemolyticus, and Escherichia coli. It was observed that positive samples in the microbiological examination showed total bacterial count between $9.10{\times}10^3$ to $6.94{\times}10^6$ colony forming units/mL, SCC between 42,000 to 4,320,000 cells/mL and ECM ranging from 1.85 to 7.40 mS/cm. It was also found that the teat cups had high microbial counts indicating poor hygiene, and even faults in the cleanliness of the animals' waiting room were observed. It is concluded that values of SCC above 537,000 cells/mL and ECM above 3.0 mS/mL are indications of mammary gland infection for this herd; however, the association of these values with a microbiological analysis is necessary to more accurately evaluate the health status of mammary glands with subclinical mastitis. Conclusion: Through phenotypic characterization of bacteria involved in the samples, the genera Staphylococcus spp., Streptococcus spp., and Corynebacterimum bovis were the most prevalent in this study. Faults in environment and equipment hygienization are factors that are directly associated with mastitis.

An Experimental Study of the Fuel Additive to Improve the Performance of a 2-Stroke Large Diesel Engine (2행정 대형 디젤엔진의 성능향상을 위한 연료첨가제의 실험적 연구)

  • Ryu, Younghyun;Lee, Youngseo;Nam, Jeonggil
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.39 no.6
    • /
    • pp.620-625
    • /
    • 2015
  • In an effort to reduce the onset of global warming, the International Maritime Organization Marine Environment Protection Committee (IMO MEPC) proposed the reduction in ship speeds as a way of lowering the proportion of carbon dioxide ($CO_2$) in the Green House Gas emissions from ships. To minimize fuel costs, shipping companies have already been performing slow steaming for their own fleets. Specifically, the slow steaming approach has been adopted for most ocean-going container lines. In addition, because of the increased marine fuel cost that is required to enable increased capacity, there is an urgent need for more advanced fuel-saving technologies. Therefore, in this present study, we propose a fuel-cost reduction method that can improve the performance of diesel engines. We introduce a predetermined amount (0.025% of the amount of fuel used) of fuel additive (oil-soluble calcium-based organometallic compound). For improved experimental accuracy, as the test subjects, we utilize a large two-stroke diesel engine installed in land plants. The loads of the test engine were classified as low, medium, and high (50, 75, and 100%, respectively). We compare the engine performance parameters (power output, fuel consumption rate, p-max, and exhaust temperature) before and after the addition of fuel additives. Our experimental results, confirmed that we can realize fuel-cost savings of at least 2% by adding the fuel additive in low load conditions (50%). Likewise, the maximum combustion pressure was found to have increased. On the other hand, we observed that there was a reduction in the exhaust temperature.

Delamination Evaluation of Thermal Barrier Coating on Turbine Blade owing to Isothermal Degradation Using Ultrasonic C-scan Image (초음파 C-scan을 이용한 터빈 블레이드 열차폐코팅의 등온열화에 의한 박리 평가 기법)

  • Lee, Ho-Girl;Kim, Hak-Joon;Song, Sung-Jin;Seok, Chang-Sung
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.36 no.5
    • /
    • pp.353-362
    • /
    • 2016
  • Thermal barrier coating (TBC) is an essential element consisting of a super-alloy base and ceramic coating designed to achieve long operational time under a high temperature and pressure environment. However, the top coat of TBC can be delaminated at certain temperatures with long operation time. As the delamination of TBC is directly related to the blade damage, the coupling status of the TBC should be assured for reliable operation. Conventional studies of nondestructive evaluation have been made for detecting generation of thermally grown oxide (TGO) or qualitatively evaluating delamination in TBC. In this study, the ultrasonic C-scan method was developed to obtain the damage map inside TBC by estimating the delamination in a quantitative way. All specimens were isothermally degraded at $1,100^{\circ}C$ with different time, having different partial delamination area. To detect partial delamination in TBC, the C-scan was performed by a single transducer using pulse-echo method with normal incidence. Partial delamination coefficients of 1 mm to 6 mm were derived by the proportion of the surface reflection signal and flaw signal which were theoretical signals using Rogers-Van Buren and Kim's equations. Using the partial delamination coefficients, the partial delamination maps were obtained. Regardless of the partial delamination coefficient, partial delamination area was increased when degradation time was increased in TBC. In addition, a decrease in partial delamination area in each TBC specimen was observed when the partial delamination coefficient was increased. From the portion of the partial delamination maps, the criterion for delamination was derived.

A Study on the characteristic analysis and optimization according to Ballast design of Induction Lamp (고출력 무전극램프의 점등회로 설계를 통한 특성분석 및 최적화에 관한 연구)

  • Chung, Young-Il;Jung, Dae-Chul;Park, Dae-Hee;Kim, Yong-Kab
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
    • /
    • v.10 no.1
    • /
    • pp.31-37
    • /
    • 2017
  • In this paper, we implemented for the development of a high output induction lamp system, which lamp design is optimized by gas type, mixing ratio, pressure and discharge tube size, amalgam type and mixing ratio, and characteristics of ferrite core in the lamp. It's the circuit design by improving the power factor and efficiency according to the driving method, which has analyzing the characteristics according to the waveform and frequency. Finally, luminaries design part for applying the optimal lighting system considering the surrounding environment, the characteristics of the lighting circuit for electrodeless lamp has analyzed and the improvement has been proceeded. In conclusion, the driving frequency has optimized at 135kHz with degrading $7{\sim}10^{\circ}C$ based on the results of the optical characteristics of the induction lamp on peak noise FET(Q3,Q4) damage.

A Study on the Metamorphism of Gneisses in the Northern Gohung Area, Chonnam (전라남도 고흥 북부지역에 분포하는 편마암류의 변성작용에 관한 연구)

  • Shin, Sang-Eun;Cho, Kye-Bok;Park, Bae-Young
    • Journal of the Korean earth science society
    • /
    • v.25 no.6
    • /
    • pp.443-473
    • /
    • 2004
  • In northern Gohung granitic gneiss, porphyroblastic gneiss and migmatitic gneiss are widely distributed. Gneisses were plotted in granodiorite domain on an lUGS silica-alkali diagram. The amounts of trace elements (Li, Zn, Sc, Sr, Ni, V Y etc.) vs. $SiO_2$, somewhat decreased. Plagioclase showed a wide compositional range ($An_{32-48}$). $X_{alm}$ and $X_{sps}$ were higher in garnet rim and $X_{pyp}$ in garnet core. The rocks in the study area were formed from S and I-type magmas which generated from syn-collision and the late to post-orogenic tectonic environment. Metamorphic P-T conditions u·ere low to medium pressure, high temperature (803-913$^{\circ}C$, 6.1-7.3 kb) and overprinted by retrograde metamorphism (570-726$^{\circ}C$, 2.2-5.1 kb) and chloritization.

A Study on the Combustion Flow Characteristics of a Exhaust Gas Recirculation Burner with the Change of Outlet Opening Position (배기가스 재순환 버너에서 연소가스 출구 위치에 따른 연소 유동 특성에 관한 연구)

  • Ha, Ji-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.8
    • /
    • pp.8-13
    • /
    • 2018
  • Nitrogen oxides (NOx) have recently been very influential in the generation of ultrafine dust, which is of great social interest in terms of improving the atmospheric environment. Nitrogen oxides are generated mainly by the reaction of nitrogen and oxygen in air in a combustion gas atmosphere of high temperature in a combustion apparatus such as thermal power generation. Recently, research has been conducted on the combustion that recirculates the exhaust gas to the cylindrical burner by using a piping using a Coanda nozzle. In this study, three types of burners were carried out through computational fluid analysis. Case 1 burner with the outlet of the combustion gas to the right, Case 2 burner with both sides as gas exit, Case 3 burner with left side gas exit. The pressure, flow, temperature, combustion reaction rate and distribution characteristics of nitrogen oxides were compared and analyzed. The combustion reaction occurred in Case 1 and Case 2 burner in the right direction with combustion gas recirculation inlet and Case 3 burner in the vicinity of mixed gas inlet. The temperature at the outlet was about $100^{\circ}C$ lower than that of the other burners as the Case 2 burner was exhausted to both sides. The NOx concentration of Case 1 burner at the exit was about 20 times larger than that of the other burners. From the present study, it could be seen that it is effective for the NOx reduction to exhaust the exhaust gas to both side gas exits or to exhaust the exhaust gas to the opposite direction of inlet of recirculation gas.

Gas/particle Partitioning of PAHs Segregated with Particle Size in Equilibrium States (대기 중 PAHs의 입경별 가스/입자 분배평형에 관한 연구)

  • Park, Jin-Soo;Lee, Dong-Soo;Kim, Jong-Guk
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.27 no.12
    • /
    • pp.1270-1276
    • /
    • 2005
  • When gas/particle partitioning of PAHs in the atmosphere approached an equilibrium state, the slope of linear regression between gas/particle partitioning coefficient($logK_p$) and subcooled liquid vapour pressure($logP_L^O$) was -1. But it was alleged that the slope of equilibrium state might not be -1 in real atmospheric environment due to heterogeneous characteristics of particulate matter. In This study, it would be found if gas/particle partitioning of PAHs segregated with particle size in equilibrium state was based on the hypothesis mentioned above. We have calculated the slopes of $logK_p$ v.s. $logP_L^O$ after collecting 10 set samples which consisted of particulate and vaporous phases. The slope was close to -1 in equilibrium states. But despite of equilibrium state, all slopes segregated with particle size were not close to -1 and those were gentler with larger particle size. The difference of slopes in equilibrium states was almost against the assumption of gas/particle partitioning theory. When the gas/particle partitioning was due to adsorption, the desorption enthalpy was different in each particle size. When it was absorption, the activity coefficient was different. The difference of desorption enthalpy and activity coefficient in each particle size indicate the heterogeneous characteristics of the bulk particle. This may be the reason for slope variation with particle size even though in an equilibrium state.

Data Acquisition System Applying TMO for GIS Preventive Diagnostic System (GIS 예방진단시스템을 위한 TMO 응용 데이터 수집 시스템)

  • Kim, Tae-Wan;Kim, Yun-Gwan;Jang, Cheon-Hyeon
    • The KIPS Transactions:PartA
    • /
    • v.16A no.6
    • /
    • pp.481-488
    • /
    • 2009
  • GIS is used to isolate large power electrical equipment using SF6 gas. While GIS has simple structure, it has few break down, relatively high reliability. But it is hard to check up faults for reason of pressure. Faults of GIS should have a ripple effect on community and be hard to recovery. Consequently, GIS imports a preventive diagnostic system to find internal faults in advance. It is most important that reliability on the GIS preventive diagnostic system, because it estimates abnormality of system by analysis result of collected data. But, exist system which used central data management is low efficiency, and hard to guarantee timeliness and accuracy of data. To guarantee timeliness and accuracy, the GIS preventive diagnostic system needs accordingly to use a real-time middleware. So, in this paper, to improve reliability of the GIS preventive diagnostic system, we use a middleware based on TMO for guaranteeing timeliness of real-time distributed computing. And we propose an improved GIS preventive diagnostic system applying data acquisition, monitoring and control methods based on the TMO model. The presented system uses the Communication Control Unit(CCU) for distributed data handling which is supported by TMO. CCU can improve performance of the GIS preventive diagnostic system by guaranteeing timeliness of data handling process and increasing reliability of data through the TMO middleware. And, it has designed to take full charge of overload on a data acquisition task had been processed in an exist server. So, it could reduce overload of the server and apply distribution environment from now. Therefore, the proposed system can improve performance and reliability of the GIS preventive diagnostic system and contribute to stable operation of GIS.

A Study of Model on the Optimal Allocation of Budget for the Efficiency of the University Evaluation (대학 평가개선을 위한 예산 최적화 배분 Model 연구)

  • Choi, Bum Soon;Lim, Wang Kyu
    • Journal of the Korea Society of Computer and Information
    • /
    • v.18 no.7
    • /
    • pp.165-174
    • /
    • 2013
  • Recently, many universities in Korea have been faced with critical crisis such as the decrease in the number of freshmen, the pressure for tuition cuts, M&A between universities and so on. Nobody has expected that universities will have this kind of difficulties. The universities are making attempts to innovate the quality of education to secure high level of education and to meet social needs to overcome these internal and external environment of crisis. For this innovation, the universities have sought to reduce the budget as well as conducted the self-evaluation to figure out their relative positions annually. Innovations cannot have having the limitation without education funds. Budget spent in universities have influences directly or indirectly on the structural improvement of the finance and on the growth of universities. The purpose of this study is to explore the decision-making method to find the optimal budget allocation so as to minimize the execution budget and to maximize the management evaluation by taking the advantage to analyse the relationship between the evaluation and the budget. Therefore, in this paper, we implement the development of the mathematical model for the University Evaluation and Budget Allocation Optimization in the form of the linear programming.

Development of Acid Resistance Velocity Sensor for Analyzing Acidic Fluid Flow Characteristics (산성 용액 내 유속 측정을 위한 내산성 센서 개발)

  • Choi, Gyujin;Yoon, Jinwon;Yu, Sangseok
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.40 no.10
    • /
    • pp.629-636
    • /
    • 2016
  • This study presents the development of an acid resistance velocity sensor that is used for measuring velocity inside a copper sulfate plating bath. First, researchers investigated the acid resistance coating to confirm the suitability of the anti-acid sensor in a very corrosive environment. Then, researchers applied signal processing methods to reduce noise and amplify the signal. Next, researchers applied a pressure-resistive sensor with an operation amplifier (Op Amp) and low-pass filter with high impedance to match the output voltage of a commercial flowmeter. Lastly, this study compared three low-pass filters (Bessel, Butterworth and Chebyshev) to select the appropriate signal process circuit. The results show 0.0128, 0.0023, and 5.06% of the mean square error, respectively. The Butterworth filter yielded more precise results when compared to a commercial flowmeter. The acid resistive sensor is capable of measuring velocities ranging from 2 to 6 m/s with a 2.7% margin of error.