• Journal of the Korean Wood Science and Technology
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• 제38권2호
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• pp.101-107
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• 2010

Heat treatment was performed to improve sound absorption properties for four tree species; Tulip tree, Korean Paulownia, Red pine and Costata birch, at temperature of $175^{\circ}C$ and $200^{\circ}C$under vacuum condition. Sound absorption properties of two kinds of boards, which were in radial and tangential sections, were measured under a frequency range of 100 to 3200 Hz by the two microphone transfer function method. It was found that sound absorption properties were increased by heat treatment and the efficiency was higher at $200^{\circ}C$ than that at $175^{\circ}C$. Even Costata birch had a little effect on low temperature of $175^{\circ}C$, $200^{\circ}C$ heat treatment for sound absorption property, the efficiencies of sound absorption were 14, 19%, respectively. The efficiencies of sound absorption ranged 22 to 120% for heat-treated Tulip tree, Korean Paulownia.

• Computers and Concrete
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• 제34권1호
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• pp.123-135
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• 2024

Strain-hardening cement-based composites (SHCC) under cracked condition exhibits remarkable capillary absorption due to water ingress from multiple cracks. Surface treatment using water repellent agents is an effective way for improving water resistance of SHCC, but the water resistance may remarkably decrease when cracks penetrate impregnation depth. Another way is to add water repellent agents directly into the mixture, offering SHCC integral water repellency even if cracks form later. However, although integral water repellent treatment has been proved feasible by previous studies, there is still lack of simulation work on the treated SHCC for evaluating its durability. This study presents a simulation method for capillary absorption of cracked SHCC with integral treatment based on a multi-scale approach proposed in the authors' previous work. The approach deals with water flows in bulk matrix and multiple cracks using two individual transport equations, respectively, whereas water absorbed from a crack to its adjacent matrix is treated as the mass exchange of the two equations. In this study, the approach is enhanced for the treated SHCC by integrating the influencing of water repellency into the two transport equations as well as the mass exchange term. Using the enhanced approach, capillary absorption of water repellent SHCC under cracked condition is simulated, showing much more reduced water ingress than the untreated concrete, which is consistent with total absorption data from previous tests. This approach is also capable of simulating water spatial distribution with time in treated SHCC reasonably.

• 복식
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• 제55권5호
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• pp.101-107
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• 2005

In this article, mordant absorption rate by the Change of temperature and fabric, discharge level by water washing, mordant density and method in mordant dye are going to be handled. Besides, how treatment method will have an effect on absorption rate and color, is also going to be covered. An atom extinction photometer was used to measure the amount of mordant absorbed in fabric at each temperature and mordant type. It turned out that absorption rate differs according to the type of mordant and sample or temperature. Also it turned out that the mordant input amount has little influence on absorption rate, that is to say, if though you use more mordants, just tiny amount of mordant is going to be absorbed in cloth. It is true that the higher temperature goes up, the better mordant absorption gets. It is found that the type of mordant and sample, treatment period affects the discharge rate. Normally $15{\~}98\%$ mordant comes off the fabric by water washing, to be specific, $17{\~}47\%$ Iron by water washing and it has better performance on cotton and nylon than silk, $1\%{\~}52\%$ Aluminum by water washing and better absorption on silk, $36{\~}89\%$ Chrome by water washing and better absorption on silk, $50{\~}89\%$ copper by water washing and better absorption on silk, poor on cotton. The examination of the K/S values and colors between before and after soaping has been conducted under the circumstance that the test fabrics had been treated at $80^{\circ}C$ for 30 minutes with $0.2\%$ soaping solution. In case of pre-mordanted fabrics, the K/S value nosedived after soaping, meanwhile densely mordanted fabric's K/S value soared but after soaping, it dropped sharply. It turned out that soaping treatment deteriorates absorption much more than water washing. It's considered that $0.1 \%$ (W/V) of mordant density is appropriate.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.149-154
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• 2018

The changes in sound absorption capability and air permeability of Malas wood after high temperature heat treatment were investigated. The average air permeability of Malas in longitudinal direction after heated under the temperature of $190^{\circ}C$ during 3 hours was about 23.48 darcys and that of control was about 3.11 darcys. The noise reduction coefficients of Malas specimens were 17% for treatment and 10% for control. The means of sound absorption coefficient of specimens in the frequency range of 50~6,400 Hz were 42% for treatment and 17% for control, respectively.

• 펄프종이기술
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• 제48권3호
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• pp.30-36
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• 2016

This study was conducted to investigate the influence of the changes in handsheet structure by beating, wet pressing and the addition of wood flour spacer on the water absorption and the moisture absorption properties. The higher beating treatment of BKP resulted in the denser structure of handsheet samples, which leaded to the lower water and moisture absorption. The wet pressing showed the similar effects by reducing the bulk of handsheets. In case of the handsheet samples with similar bulk structure made of different beaten pulps, the severer beating treatment increased the water absorption and the moisture absorption. The addition of the wood flour spacer resulted in the higher bulk following the higher water and moisture adsorption. Since the water and the moisture absorption properties of paper products could greatly affect on not only the product quality but also the process runnability, the control of the water response of paper product has been considered as very important technology. The results of this study might be useful for control of water and moisture absorption properties of paper products.

• 한국미생물·생명공학회지
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• 제50권4호
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• pp.477-487
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• 2022

Probiotics provide a symbiotic relationship and beneficial effects by balancing the human intestinal microbiota. The relationships between microbiota changes and various diseases may predict health abnormalities and diseases. Treatment with vitamins and probiotics is one therapeutic approach. To evaluate the effect of probiotics on vitamin absorption, we chose Lactobacillus rhamnosus CBT-LR5 treatment, which has resistance to vitamin C-inducible toxicity, with vitamins in high-fat diet (HFD)-induced obesity models. CBT-LR5 affected the absorption of micronutrients, such as ionic minerals and water-soluble vitamins. An increase in vitamin C absorption by CBT-LR5 enhanced the antioxidant response in HFD-induced obesity models. Increased vitamin B absorption by CBT-LR5 regulated lipid metabolism in HFD-induced obesity models. These favorable effects of CBT-LR5 on the absorption of vitamins should be investigated as candidate therapeutic target treatments for metabolic diseases.

• 한국음향학회지
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• 제40권6호
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• pp.649-659
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• 2021

벽면 흡음 처리는 잔향의 제어에는 효과적이나, 잔향이 큰 공간의 경우에는 넓은 면적에 대한 적용이 필요하며, 각 벽면의 흡음은 음성 명료도에 다르게 영향을 미친다. 본 연구에서는 실내 음성 명료도의 관점에서 빔포밍 수음장치에 대한 잔향 제어를 위해 흡음 처리가 가장 효과적인 벽을 선택하는 모사 방법을 제안한다. 고정된 위치의 빔포밍 수음어레이에 대해, 화자 혹은 스피커에서 방출된 음향이 각 벽면과 충돌하는 변수를 이용해 벽면 중요도 계수를 정의하고, 이를 이용해 흡음 처리에 따른 수음부의 음성개선 효과를 예측하는 방법을 제시했다. 검증을 위해 체적이 107 m³, 잔향 시간이 1.1 s인 직육면체형 실내공간에 대해 모사 실험을 진행했다. 중요도 계수가 가장 높은 벽면에 헬름홀츠 흡음기를 적용할 때 수정된 음성 명료도는 500 Hz, 1 kHz에서 각각 5.1 dB와 4.8 dB, 또 음성전달 지수는 0.06만큼의 향상이 예측되었는데, 이는 상용코드의 계산 결과와 차이인지 역치(Just-Noticeable Difference, JND) 이내의 차이로 일치했다. 분석결과, 벽면 중요도가 가장 높은 곳에 흡음 처리한 결과는 면적이 가장 넓은 천장에 같은 흡음률을 적용할 때보다 음성 명료도 지수가 JND 이상으로 더 개선되는 것을 알 수 있었다.

• 한국기계가공학회지
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• 제12권5호
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• pp.76-85
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• 2013

This study was carried out to investigate the relation between surface roughness and heat absorption capability of materials for solar collector. For this purpose, 3 kinds of materials (copper, aluminum, iron), 5 kinds of surface roughness (scrubber, alumina sand #80, #200, #400, glass bead) and 2 kinds of surface treatment (black chrome plating, copper black coating) were used for finding optimal conditions to apply solar collector. As the results, it was confirmed that the optimal relations between surface roughness and surface treatment as well as optimal materials were necessary. Further, heat absorption capability was showed good results in cases of copper materials, glass bead and black chrome plating.

• 동아시아식생활학회지
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• 제11권3호
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• pp.209-218
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• 2001

This study was conducted to examine the water absorption, water-holding capacity, color and mineral contents in natural and cultured dried sea mustards on soaking treatment. Four dried samples of natural and cultured sea mustards were used for the experiments. The effects of soaking treatment on water absorption and water-holding capacity in sea mustards were examined, as the results, these were rapidly accelerated 5 minutes after soaking. It showed that water-holding capacity was significantly high in the case of high absorption of water by soaking. The L, a and b values were increased until 30 minutes after soaking. There was significant difference for potassium content between dried natural and dried cultured sea mustards and the natural sea mustard was 10 times as high as the cultured sample. All mineral elements in these materials were significantly decreased and especially, potassium were significantly more decreased at 50~80% of total content by soaking treatment. Ca/ P ratio in these materials by soaking was about 2~3 : 1 levels.

• Journal of the Korean Wood Science and Technology
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• 제33권4호통권132호
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• pp.9-14
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• 2005

목재에 대한 탈리그닌처리에 의한 목재의 흡음성능과 구조적 특징의 변화를 관찰하고자 목재횡단방향으로 채취한 원반형시험편을 탈리그닌처리하여 무 처리 목재와 구조적 특징의 변화를 관찰하고, 흡음율을 측정 비교하였다. 측정주파수범위에서 탈리그닌처리한 시험편이 보통의 시험편보다 높은 흡음율을 나타내었으며, 특히 2~4 KHz의 주파수영역에서는 50% 정도 높은 흡음율을 나타내었다. 또한 탈리그닌처리한 목재는 무 처리 목재보다 중량이 8% 정도 감소하였으며, 탈리그닌처리한 목재의 횡단면에서는 다수의 미세할렬이 발생하여 이들이 흡음공극으로 작용하여 특정주파수영역에서 흡음율이 증가된 것으로 사료된다.