• Title/Summary/Keyword: Absorption-Reduction

Search Result 766, Processing Time 0.026 seconds

Sound Absorption Rate and Sound Transmission Loss of CLT Wall Panels Composed of Larch Square Timber Core and Plywood Cross Band

  • Kang, Chun Won;Jang, Sang Sik;Kang, Ho Yang;Li, Chengyuan
    • Journal of the Korean Wood Science and Technology
    • /
    • v.47 no.1
    • /
    • pp.33-39
    • /
    • 2019
  • The square timbers of larch having cross section of $90mm{\times}90mm$ were glued laterally to be formed $1,200mm{\times}2,400mm$ panels which were used as cores for CLT wall panels. Then, structural plywood panels having size of $1,200mm{\times}2,400mm$ were used as cross band covering the small square timber cores to manufacture CLT wall panels. The sound absorption rate of CLT wall panels and polyester board attached CLT wall panels were investigated. The mean sound absorption coefficients of the former and the latter in the frequency range of 100-6400 Hz were 0.21 and 0.74, respectively. The noise reduction coefficients (NRC) of those were 0.21 and 0.40, respectively. Also, the mean sound transmission loss of CLT wood panel in the frequency range of 50-1600 Hz was 45.12 dB and that value at the frequency of 500 Hz was 42.49 dB. It was suggested that the polyester board attached CLT wall panels could be used as housing wall because of its high sound absorption rate and high sound transmission loss.

Decreased absorption of midazolam in the stomach due to low pH induced by co-administration of Banha-sasim-tang

  • Jo, Jun Hyeon;Kim, Sun Joo;Nam, Woong Shik;Seung, Eun Ji;Lee, Sangkyu
    • Environmental Analysis Health and Toxicology
    • /
    • v.31
    • /
    • pp.16.1-16.9
    • /
    • 2016
  • Objectives Banha-sasim-tang (BST), which consists of seven different herbs, is one of the most popular herbal formulae for treating gastrointestinal disorders in Eastern Asia. The commonly used herbal medicine is often co-administered with other therapeutic drugs, which raises the possibility of herb-drug interactions and may modify the clinical safety profile of therapeutic drugs. Methods We investigated the potential herb-drug interactions between BST extract and midazolam (MDZ) in mice. The area under the plasma concentration-time curve (AUC) of MDZ and 1'-hydroxymidazolam (1'-OH-MDZ) was evaluated for both oral and intraperitoneal administration of MDZ, following oral administration of BST (0.5 and 1 g/kg). Results It was found that the AUC of MDZ and 1'-OH-MDZ was lower in case of oral administration of MDZ. Administration of BST extract was not associated with hepatic cytochrome P450 activity. BST extract induced a strong reduction in pH and it has been reported that oral mucosal absorption of MDZ is lower at low pH. The decreased absorption rate of MDZ might be caused by the ingredients of BST and may not be related to other factors such as increased excretion of MDZ by P-glycoprotein. Conclusions The altered pharmacokinetics of midazolam caused by co-administration with BST in vivo could be attributed to a decrease in pH and subsequent reduction of MDZ absorption rate.

Probability-Based LCCO2 Evaluation for Undergroung Structture with Repairing Timings Exposed to Carbonation (탄산화에 노출된 지하구조물의 보수횟수에 따른 LCCO2 평가)

  • Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
    • /
    • v.5 no.3
    • /
    • pp.239-246
    • /
    • 2017
  • RC(Reinforced Concrete) structures can keep their performance during intended service life through initial service life and extension of the life through repairs. In the deterministic repairing method, cost and the related $CO_2$ emission increase with step-shaped escalation, however continuous results can be obtained through probabilistic repairing technique, and this is capable of reducing $CO_2$ emission through $CO_2$ absorption. In the work, repairing timing and $CO_2$ emission/absorption are evaluated based on the different methods like deterministic and probabilistic manner. The probabilistic technique considering $CO_2$ absorption with carbonation progress is evaluated to be very effective to reduction of $CO_2$ emission through extension of initial and additional service life due to repairs. When the variations of the service life from initial construction and repair material can be determined, the proposed technique can contribute to reduction of cost and $CO_2$ with decreasing repairing number.

Effect of Food on Ampicillin Absorption in the Rat Intestine (흰쥐의 소장에서 음식물이 암피실린의 흡수에 미치는 영향)

  • Lee, Hyun-Joo;Lee, Jeong-Hwa;Kwon, Yong-Zun;Yang, Chae-Ha;Oh, Doo-Man
    • Journal of Pharmaceutical Investigation
    • /
    • v.25 no.4
    • /
    • pp.291-298
    • /
    • 1995
  • The purpose of this study is to verify the interaction between food and ampicillin which is one of the aminopenicillins known to be absorbed by a specified dipeptide transporter in the small intestine. The absorption of ampicillin was measured in the presence of the high carbohydrate food, high fat food, and high protein food, and compared with that in the presence of the control normal food. In situ single-pass perfusion method was chosen in these experiments using two jejunal segments in the rat. Reduction in the absorption of ampicillin was not shown, when both high carbohydrate food and high fat food were co-perfused with ampicillin. When the high protein food was co-perfused with ampicillin, the difference of $C_{out}/C_{in}$ of ampicillin ratio was $0.084\;{\pm}\;0.082$, showing a trend of reduced absorption without a significance. Further, glyclysarcosine (Gly-Sar) which is a stable dipeptide in the small intestine was used in order to see the direct competitive inhibition with ampicillin on the dipeptide transporter. The difference of $C_{out}/C_{in}$ ratio was $0.078\;{\pm}\;0.020$ in the presence of 10 mM Cly-Sar, showing a significant inhibition of ampicillin absorption (p < 0.02). It suggests that dietary di- and tripeptides, the digestive products of protein food, might have influence on the absorption of ampicillin, and that ampicillin could be given at the lasting state for better absorption.

  • PDF

Effect of corn gluten and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet

  • Kim, Joo-Hee;Park, Ju-Yeon;Hong, So-Young;Kim, Mi-Kyung
    • Nutrition Research and Practice
    • /
    • v.3 no.3
    • /
    • pp.200-207
    • /
    • 2009
  • This study examined the effects of com gluten (CG) and its hydrolysate consumptions on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=40) were fed a high-fat diet (40% calorie as fat) for 4 weeks. They were then randomly divided into four groups and fed the isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate A (CGHA group, 30% of protein as peptides and 70% as free amino acids) and CG hydrolysate P (CGHP group, 93% of protein as peptides and 7% as free amino acids). Body weight gain, adipose tissue weights, nitrogen balance, absorptions of energy, protein and fat, lipid profiles in plasma, liver and feces and hepatic activities of camitine palmitoyl transferase (CPT), fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH) were assessed. The CGHA diet had the highest amount of BCAAs, especially leucine, and most of them existed as free amino acid forms. The CGHA group showed significant weight reduction and negative nitrogen balance. Protein absorption and apparent protein digestibility in the CGHA group were significantly lower than those in other groups. Adipose tissue weights were the lowest in the CGHA group. Activity of CPT tended to be higher in the CGHA group than in other groups and those of FAS, ME and G6PDH were significantly lower in the CGHA group than in other groups. In conclusion, the CGHA diet which had relatively high amounts of free amino acids and BCAAs, especially leucine, had a weight reduction effect by lowering adipose tissue weight and the activities of FAS, ME and G6PDH in experimental animals, but it seemed to be a negative result induced by lowering protein absorption, increasing urinary nitrogen excretion and protein catabolism.

Study on the design of the passenger cars bumper rail to reduce the weight (자동차 범퍼 레일의 경량화 설계에 관한 연구)

  • 김이규;조규종
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.563-566
    • /
    • 2000
  • Recently vehicle development trend puts emphasis on cost reduction and performance improvement through weight reduction, and safety security to protect passenger and chassis against external impact. Primary factors effected on vehicle safety are chassis structure, chassis system, and safety equipment like bumper. Research in part of weight reduction is proceeding actively about prohibition of over-design and material through optimal design method. Bumper in these factors is demanded two of all factors, safety security and weight reduction. It is the part that prohibits or reduces a physical impact in low speed crash. Bumper is composed of a few parts but this study exhibits the shape of bumper rail has a role on energy absorption of safety security and weight reduction from structure analysis of bumper rail's variable shape surface.

  • PDF

A Study on Squeal Noise Control by Absorption Treatment in Urban Rail Transit System (흡음에 의한 도시철도 곡선부 스퀼 소음저감에 관한 연구)

  • 최진권;이재원;장서일
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.11 no.4
    • /
    • pp.58-64
    • /
    • 2001
  • Sound absorbing materials are applied to the exposed surfaces of curvet subway tunnel for the reduction of curving noise level. Before the treatment, acoustical engineering simulation is performed to predict the noise level reduction for different kinds and amounts of absorbing material. The principle of geometrical acoustics is utilized to perform the simulation efficiently and accurately. The noise bevels of the inside and outside of running car body are measured to find the noise level reduction. The average noise level reduction of 8 dB has been attained. It has been shown that the simulated results are comparable to the measured ones.

  • PDF

Noise Reduction of a Range Hood using Micro-Perforated Panel (미세 다공판을 이용한 레인지 후드의 소음저감)

  • Kim, Deok-Han;Song, Hwa-Young;Lee, Dong-Hoon;Lee, Chang-Kun;Kim, Dong-Yun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.1205-1208
    • /
    • 2006
  • This paper introduces a study for the noise reduction of a range hood for household. Generally, range hoods have a built-in sirocco fan from which rumbling noise is generated. Though the rumbling noise has low noise level. this noise makes most of the users nervous due to the its low frequency characteristics. For the purpose of noise reduction, in this study, a micro-perforated panel system is installed in the fan housing of range hood. From the experimental results, it is confirmed that the noise level emitted from the range hood is decreased over 2dB(A) in all frequency regions due to the effect of noise reduction by micro-perforated panel system.

  • PDF

A Research on the Noise Reduction of a Kitchen Ventilation System and the Prediction of Sound Distribution in a Kitchen and Room (주방환기 시스템의 소음 저감과 실내 음장분포 예측에 관한 연구)

  • Song, Hwa-Young;Lee, Dong-Hoon;Lee, Chang-Kun;Kim, Dong-Yun;Hong, Byung-Kuk
    • Proceedings of the SAREK Conference
    • /
    • 2005.11a
    • /
    • pp.494-499
    • /
    • 2005
  • This paper introduces a study for the noise reduction of a range hood for household. Generally, range hoods have a built-in sirocco fan from which harsh noises are generated. Though the harsh noises have low noise level, these kinds of noises make most of the users nervous. For the purpose of noise reduction, in this study, a perforated plate system is installed in the fan housing of range hood. From the experimental results, it is confirmed that the noise level emitted from the range hood was decreased more than 10dB(A) in all 1/3 octave bands due to the effect of noise reduction by perforated plate systems.

  • PDF

A Research on the Noise Reduction of Range Hood for Household (가정용 레인지 후드의 소음저감에 관한 연구)

  • Hong, Byung-Kuk;Song, Hwa-Young;Lee, Dong-Hoon;Lee, Chang-Kun;Kim, Dong-Yun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.11a
    • /
    • pp.449-452
    • /
    • 2005
  • This paper introduces a study for the noise reduction of a range hood for household. Generally, range hoods have a built-in sirocco fan from which squawky noises are generated. Though the squawky noises have low noise level, these kinds of noises make most of the users nervous. For the purpose of noise reduction, in this study, a perforated plate system is installed in the fan housing of range hood. From the experimental results, it is confirmed that the noise level omitted front the range hood is decreased above 2dB(A) in all frequency regions due to the effect of noise reduction by perforated panel system.

  • PDF