• Title/Summary/Keyword: Weighing chamber

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Development and Evaluation of an Inexpensive Weighing Chamber for Particulate Filters (미세먼지 여지의 무게 측정을 위한 저비용 계량챔버 개발 및 성능평가)

  • Jun-Hyun Park;Ho-Jin Lim
    • Journal of Environmental Science International
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    • v.32 no.2
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    • pp.131-137
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    • 2023
  • Filter and microbalance sensitivity in measuring fine particulate matter mass is greatly influenced by particulate properties and environmental factors. Temperature and humidity control inside a measuring chamber with a microbalance, and neutralization of static charges on filters are essential for consistent filter weighing. Commercial weighing chambers are expensive with a unit price of tens of millions won. This study developed an inexpensive weighing chamber for weighing fine particulate matter and evaluatedits weighing performance. A microbalance with 1 ㎍ precision was used to measure the weight of a filter. The microbalance was set in a transparent acrylic enclosure (100 × 60 × 65 cm3) equipped with temperature and humidity control equipments. Weighing performance of the chamber was examined using Teflon filters with or without different particulate sample types. Temperature and humidity were maintained at approximately 23.2±1.2 ℃ and 36.2±1.8℃ for 8 days, respectively.

Application of new external total ring prostheses made by drip chamber of intravenous administration set in normal dogs (정상 견에서 수액세트 점적통을 이용한 새로운 기관 외부 보철링의 적용)

  • Jeong, Sang-hyi;Jeong, Soon-wuk
    • Korean Journal of Veterinary Research
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    • v.44 no.1
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    • pp.137-141
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    • 2004
  • The purpose of this study was to compare easiness of application of polypropylene external total ring prosthesis (PPTRP, Group A) with that of polyvinylchloride external total ring prosthesis (PVCTRP, Group B), which were used for surgical correction of tracheal collapse in dogs. PPTRP was made from 3 ml syringe and PVCTRP from the drip chamber of intravenous administration set. Prostheses of group A (n=5) and B (n=5) were placed to cervical trachea in clinically normal 10 dogs, respectively weighing between 4 kg and 6 kg. There were mild coughing and swelling in one to three dogs of both groups for 3 days after surgery. No exercise intolerance was observed in both groups after surgery. There were no different results of clinical signs and radiographic views after surgery between group A and group B. The time (mean${\pm}$SD) to make total ring prosthesis, group A took $23.2{\pm}1.9$ minutes which was remarkably longer than that $(4.6{\pm}0.3)$ of group B. Also, the time to place around trachea, group A required $61.8{\pm}8.8$ minutes and group B $38.4{\pm}8.0$ minutes. Conclusionly, PVCTRP was timesaving and easier to make, fix, and suture than those of PPTRP. PVCTRP may be used alternatively to PPTRP for the tracheal collapse to treat in dogs.

In Vivo Estimation of Emax and Ejection Fraction Using Dynamic Spatial Reconstructor (역동적 삼차원 재구성기로 측정한 In Vivo 상태의 좌심실의 Emax 와 박출계수)

  • 김광호
    • Journal of Chest Surgery
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    • v.21 no.2
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    • pp.223-230
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    • 1988
  • Emax, end-systolic pressure-volume relationship, has been established as a new concept which can be representative of ventricular contractility itself since 1970s. Comparing to ejection fraction[EF], Emax is independent of preload and afterload. However Emax has not been proved precisely in non-thoracotomized condition because current methods have limitation in measuring ventricular chamber volume accurately in in viva state. The Dynamic Spatial Reconstructor[DSR], high speed computerized tomography, can measure ventricular chamber volume accurately throughout cardiac cycle in non-thoracotomized state. So Emax and EF of the left ventricle was tried to measure precisely in in vivo condition with DSR. Emax was compared to EF to estimate its ability to evaluate ventricular contractility. 5 mongrel dogs, weighing 15-16kg, were used for measuring Emax and EF of the left ventricle in 3 or 4 different loading conditions using DSR. Emax value in 5 dogs was from 2.62 to 10.49. Each dog has one Emax value regardless of loading conditions. However EF in 5 dogs varies depending on loading conditions. The conclusions are that Emax is useful in in viva state and EF varies depending on loading conditions. So Emax should be tried to use in clinical situation rather than EF because it is always representative of contractility itself regardless loading conditions in in viva state.

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Resolution of Malignant Hypertension after Single-Chamber Permanent Pacemaker Implantation in a Dog with 3rd Degree AV Block

  • Su-Min Park;Woo-Jin Song;Hwa-Young Youn
    • Journal of Veterinary Clinics
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    • v.40 no.1
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    • pp.50-55
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    • 2023
  • A 10-year-old spayed female Cocker spaniel weighing 6.64 kg was presented with a sign of syncope. Electrocardiographic findings revealed pathologic atrioventricular (AV) block alternating 3rd degree AV block, non-responsive to atropine. Before pacemaker implantation, several anti-hypertensive medications were administered, but there was no improvement. After pacemaker implantation, the heart rate and systemic arterial systolic blood pressure were immediately improved. This is the first report on the resolution of an AV block and malignant systemic hypertension after a pacemaker implant in veterinary medicine.

Structural Behavior of the Cylinder Cover Stud of Marine Diesel Engine (박용엔진 실린더 커버 스터드의 구조거동 분석)

  • Kim, Byung-Joo;Lee, Jae-Ohk;Park, Jin-Soo;Kim, Se-Lak
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.267-268
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    • 2006
  • The cylinder cover stud of low-speed marine diesel engine is more than just a stud. It is a large structural element occasionally weighing over 200 kg used for assembling the combustion chamber components. Therefore, to understand the structural behavior of the stud and design it safely is quite important considering a catastrophic failure which can be arisen from an inadequate use of it. In this paper, the analysis results of the structural behavior of the stud is introduced. Strain measurement results compared with FE analysis results are summarized. The results showed that 1) the stud stress increased with engine operating load, 2) the maximum stress amplitude was about 10 MPa which is far smaller than the stud's fatigue strength of 61 MPa, 3) the stress ratio is higher than 0.9 and the stud's load factor is about 20 %, and 4) about 7 % of initial pressure tightening load was reduced while changing to a nut tightened condition.

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Usefulness of ultrasound contrast media for cardiac output measurement with echocardiography

  • Yun, Je Woong;Yeon, Seong Chan;Lee, Hee Chun
    • Korean Journal of Veterinary Research
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    • v.55 no.1
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    • pp.47-52
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    • 2015
  • The purpose of this study was to determine if contrast media would enhance visualization of the endocardium for assessment of left ventricle (LV) function. In addition, differences between pre- and post-contrast evaluation for the cardiac output measurements including the modified Simpson's method and automated contour tracking (ACT) method were examined. Ten clinically healthy adult beagle dogs (three males and seven females) between 2~3 years old and weighing 6.6~10.8 kg were used. Echocardiographic examinations were performed to compare pre- and post-contrast LV endocardium visualization using a segmental scoring method. Two different methods for measuring cardiac output were also compared. LV visualization was significantly enhanced in post-contrast echocardiography (p < 0.01). Significant differences between pre- and post-contrast measurements for the modified Simpson's method (p < 0.05) were also observed. No significant difference was found for the ACT method. Contrast echocardiography provides better LV chamber opacification and significantly improves wall segment visualization. Furthermore, contrast echocardiography for measuring cardiac output is helpful for the modified Simpson's method.

Idiopathic Atrial Standstill in an Old English Sheepdog Cross Dog (Old English Sheepdog Cross Dog에서의 특발성 심방정지)

  • Suh, Sang-il;Choi, Ran;Hyun, Changbaig
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.330-333
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    • 2015
  • An 1 year old intact male mixed dog (weighing 20 kg) was presented with primary complaints of abdominal distension and severe exercise intolerance. Electrocardiogram found profound bradycardia (46-79 beats/min) with atrial standstill. Laboratory studies found no particular abnormalities. Serum cortisol and T4 concentration were within normal range. Diagnostic imaging studies revealed generalized cardiomegaly, ascites, dilation in all cardiac chambers, absence of atrial contraction, absence of transmitral A-peak, mitral and tricuspid valve insufficiency and normal left ventricular systolic dimension. Based on diagnostic findings, the case was diagnosed as idiopathic atrial standstill. The dog was treated with conventional therapy for heart failure.

Urea Resin Treat Effects on Silk Textiles (요소수지를 주체로 한 편직물구조 개선연구)

  • 최병희;이양후;김한수
    • Journal of Sericultural and Entomological Science
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    • v.20 no.1
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    • pp.15-23
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    • 1978
  • This studies have been carried out for several years to develop more better urea resin treating process on silk textiles which may be better crease resist without harming on the textile touch feeling. Specially, this paper payed attention to minimize the necessary formaldehyde content to be condensed with urea and created a new processing method which is named as Homo Metalic Urea Resin found to be better than urea resin process. The obtained results are as followings. 1. The prepared urea resin was found to be smell-less because of minimized formaldehyde content is the least than any other reports carried out before than this. 2. A new type of urea resin has been created by using uric 2incchloride and formaldehyde which is named as Homo Metalic Urea Resin. This processing method may carry both weighing process and urea resin process. 3. Crease resistance, stiffness and bulkiness were increased through such resin treats. Homo metalic urea resin process showed better results than the urea resin process. 4. Spun silk or low twisted silk have shown better crease resistance than raw silk or high twisted silk upon the both resin treats. 5. Both treat methods were found to be good economical feasibility upon the silk finishing process. 6. Tenacity and elongation of silk fibers were found to decrease some what because of grafting or weighing results. 7. Wooly silk has been also created with specific urea resin process. Such silk could be obtained by formaldehyde gas treat with urea soaken silk in a chamber, which induced to form scale on the surface of silk fibers.

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Studies on the Nitrogenous Utilization and Basal Metabolism of Korean Native Goat (한국(韓國) 재래산양(在來山羊)의 질소대사(窒素代謝) 및 기초대사량(基礎代謝量)에 관(關)한 연구(硏究))

  • Oh, Hong Rock
    • Korean Journal of Agricultural Science
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    • v.9 no.2
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    • pp.546-555
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    • 1982
  • To evaluate the digestibility and absorbability of proteins, and the rates of energy and nitrogen(N) metabolism of the Korean native goats, studies were carried out with open type respiration apparatus based on the nitrogen-carbon method. The results on the nitrogen retention and the metabolic rate of energy, which was obtained with one male (10-month-old) and one female (24-month-old) goats, both weighing ${\simeq}20kg$, are summarized as follows. 1. When the goats were fed ad libitum the medium quality orchard grass hay, they consumed hay about 0.66 to 0.92% of body weight per day. The hay intake was remained the same even when high quality hay was provided. This amount of hay intake was relatively lower than that of dairy goat and sheep. It was believed to be partly due to the change in feeding enviroment. When fed with hay and soybean meal together, the goats ate hay about 1.06% and soybean meal about 0.60% of body weight, corresponding to 1.66% of body weight as fed basis. 2. The $CO_2$ gas produced from the goat in the open type respiration chamber and absorbed with KOH solution was estimated to be 99~117g/day. The difference in feed intake did not influence the $CO_2$ production; however, these seems to be a linea relationship between body weight and $CO_2$ production. 3. When fed orchard grass hay only, the goats showed protein digestibility of 24~41%. The protein digestibility incresed to 58.2% when fed hay and soybean meal together. A negative nitrogen balance(-0.16g N/day) was observed with goats fed 11.53g N originated from 212g hay and 150g soybean meal. Converting that nitrogen ingested to a crude protein, the amount of crude protein intake by the goats per day was 77.9g compared to 40~45g N known to be required in a day by goat weighing 20kg, indicating that the extra protein ingested was metabolized to provide energy. 4. When the male and female goats comsumed 624 kcal gross energy and 824 kcal gross energy by consuming 158g and 213g of hay, respectively, the digestible energy intake was calculated to be 260kcal for the male and 199kcal for the female goat. The daily heat production of male and female goats were 338kcal and 334kcal, respectively, when fed hay only. However, the female goat fed 212g hay and 150g soybean meal produced about 591kcal per day. Consequently, the energy requirment of the Korean native goats weighing ${\simeq}20kg$ was concluded to be $${\geq_-}$$600kcal net energy per day. 5. The fasting heat product ion of a male goat weighing 27.7kg was 412kcal per day when fasted for 2~3 days. When fasted for 3~4 days, the value decresed to 240kcal. The enviromental temperatures during the expreimental period were ranged from 19 to $34.5^{\circ}C$. The goats seemed to be panting when the chamber temperature rose to $32^{\circ}C$ or above. 6. When fed low levels of dietary protein, serum protein levels of the goats were decresed slightly ($${\leq_-}$$10%); however, urea content in the serum was observed to decrese to a great extent (3X).

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The Study on the Role of Prostaglandin in Contraction of Vas Deferens (정관운동에 있어서 prostaglandin 의 역할에 관한 연구)

  • Park, Won-Kyoo
    • The Korean Journal of Pharmacology
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    • v.19 no.2
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    • pp.1-8
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    • 1983
  • Prostaglandin(PG) is ubiquitously distributed in most mammalian tissue and their actions are complicated. Especially in autonomic nervous system, there are evidences indicating that PGs act as neuromodulators i.e., PGs, which are released in the vicinity of autonomic neuroeffector junctions, influence the release and the response of the neurotransmitter. Present study was undertaken to elucidate the interrelationship between $PGF_{2\alpha}$ and adrenergic ${\alpha}_2-receptor$ function in electrical field stimulation induced contractile response of vas deferens in rat. Male rat, weighing 150{\sim}200\;g, was sacrificed and vas deferens was obtained. The isolated vas deferens strip was placed between two platinum electrodes in temperature controlled $(37^{\circ}C)$ muscle chamber containing Tyrode's solution and the electrical field stimulation(EFS) induced contraction was recorded with Grass Polygraph(Model 7) via force displacement transducer (FT .03, Grass). The results are summarized as follows: 1) Electrical field stimulation for 1sec( 1 msec, 40 cps) induced contraction of vas deferens was completely blocked by tetrodotoxin. 2) Bretylium caused marked inhibition of the EFS-induced contraction, hut tyramine and cocaine augmented the contraction. 3) EFS-induced contraction was inhibited or little affected in distal portion of vas deferens by norepinephrine or methoxamine, but the contraction was rather augmented by the ${\alpha}-agonists$ in proximal portion. 4) Clonidine inhibited the EFS-induced contraction proportionally to the concentration in distal portion, which was blocked by yohimbine pretreatment, but in the presence of $PGF_{2\alpha}$ the blockade by yohimbine was reversed. 5) Indomethacin pretreatment reduced the effect of clonidine, but addition of $PGF_{2\alpha}$ after washing-out the indomethacin caused the contraction to the control level. From these results it is suggested that PG synthesis is a necessary step and the PG itself has a permissive role in ${\alpha}_2-adrenoceptor$ action in rat vas deferens.

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