• Title/Summary/Keyword: apparent density

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The Effect of Refining Load on the Paper Properties (고해부하가 종이의 물성에 미치는 영향)

  • 김용식;원종명
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.1
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    • pp.38-44
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    • 2001
  • The effects of refining load on the paper properties were investigated. HwBKP, SwBKP and SwUKP were refined with PFI mill at the load of 3.33 N/mm and 6.00 N/mm. Higher Scott bond was obtained at the higher refining load for three pulp used in this study. However any changes in the light scattering coefficient with the change of refining load were not observed. Although the effect of refining load on the formation index for SwUKP was not observed, higher refining load gave the better formation for HwBKP and SwBKP. The fiber mass and fiber crowding factor were not affected by the refining load. Higher apparent density and tensile index were obtained with the higher refining load. However, the higher refining load did not improve the tensile index at the same apparent density. The tear index was decreased with the increase of refining load.

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Research of Correlation Apparent density with Young′s Modulus of Cancellous bone in Injection of PMMA (PMMA주입시 망상골의 골밀도와 영율의 상관관계에 대한 연구)

  • 이중희;문희욱;박건일;채수원;이태수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1336-1340
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    • 2003
  • The compressed fracture of spine caused by osteoporosis is one of the most frequent diseases in bone fracture. Recently the vertebroplasty has drawn much attention as a medical treatment for the compressed fracture of spine, which strengthens the vertebral body and corrects deformity, and relieves pain in patients by injecting bone cement. The purpose of this research is to provide the theoretical background for the vertebroplasty by employing scientific methods and thus to find out the improvements of the conventional surgical method. By applying the engineering analysis tools to clinical study, new application fields can also be obtained

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The Effects of Enzymatic Treatment on KOCC (효소처리가 KOCC의 특성에 미치는 영향)

  • 김대영;원종명
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.4
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    • pp.34-40
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    • 2000
  • This study was carried out to evaluate the effects of enzymatic treatment on the characteristics of KOCC. Novozym 342 and Pulpzyme HC were used for this purpose. Enzymatic treatment greatly increased the freeness of KOCC and Novozym 342 was more effective. WRV was improved only when KOCC was treated with 0.1% Pulpzyme HC. Pulpzyme HC was more effective to improve the flexibility of fiber(conformability angle) than Novozym 342. Coarseness of fiber was decreased with the enzymatic treatment. Fines content greatly decreased with 0.01% addition of enzymes. Novozym 342 was more effective than Pulpzyme HC for this purpose. Apparent density, tensile index and tear index decreased with enzymatic treatment, but stiffness increased. Especially the decrease of apparent density, tensile index and tear index by the treatment with Novozym 342 was significant than those of Pulpzyme HC. Therefore Novozym 342 will be suitable for the removal of fines and for bulky sheet, otherwise Pulpzyme HC will be good.

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A Study on the Porcelain Body of $MgO-SiO_2$ System(II) ($MgO-SiO_2$ 계 자기에 관한 연구(II))

  • 이응상;이종근;최성철;안기성
    • Journal of the Korean Ceramic Society
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    • v.20 no.3
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    • pp.243-249
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    • 1983
  • This study has examined on the effect for the fitting in porcelain body of MgO-SiO system. The mixture was made of correponding in the theoretical composition of enstatite with Kyul Sung Talc and sea water magnesia cake. Hyup Jin Kaolin as clay minerals to give the mixture plasticity was added 10% by weight of the mixture. Feldspar was added inv various kinds of 1%-20% by weight of the above mixture. After the physical properties and microstructures were carefully examined the following results were obtained. 1. The addition amount of feldspar should generally be from 5% to 10% by weight of the mixture to be good for the properties of the strength and the range of the firing temperature. 2. The 5% addition amount of feldspar was good for the apparent bulk density. 3. 5% and 10% additions showed up stably excellant with respect to the various properties Therefore when we considered the apparent bulk density and the thermal shock resistance 5% addition amount of feldspar showed the most excellant properties between $1350^{\circ}C$ and $1400^{\circ}C$.

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Studies on the Kinetics for the Formation Reaction $Ti_3AI$ by SHS (Self-propagating High-temperatuer Synthesis) Method (자체반응열 고온합성법에 의한 $Ti_3AI$ 생상반응의 동력학적 연구)

  • 전광식
    • Journal of the Korean Ceramic Society
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    • v.35 no.6
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    • pp.569-574
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    • 1998
  • The thickness of flame zone reaction rate and apparent activation energy in the formation reaction of $Ti_3AI$ intermetallic compound were investigated using SHS method which sustains the reaction spontaneously and utilizes the heat generated by thye exothermic reaction itself. In this reaction the thickness of flame zone was 1.4 mm and the reaction rate was $0.4g/\textrm{cm}^2{\cdot}sec$. Also the apparent activation energy calculated using from the experimental data obtained by controlling the realtive green density was 40kJ/mol.

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Acoustic Properties of Solid Materials: Sound Speed, Transmission Coefficient, and Attenuation

  • Roh Heui-Seol;Lee Kang Il;Jung Kyung-Il;Yoon Suk Wang
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.525-528
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    • 2002
  • The speed of sound, transmission coefficient, and attenuation are measured around the center frequency 1 and 2 MHz in solid materials such as bone, sediment, rubber, and Lucite materials. Common and different characteristics of such materials in the sound speed, transmission coefficient, and attenuation are discussed. Ambiguities in estimating such acoustic characteristics we also addressed. Ultrasonic properties of the first and second kind waves are clarified for different materials. Discussions are concentrated on classes of sound speed, broadband ultrasonic attenuation (BUA), and correlations of sound speed and BUA with apparent density. New correlations of inverse sound speed square and BUA with apparent density are suggested.

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Preparation of Granule Powders for Thermal Spray Coating by Utilization of Pyrophyllite Minerals

  • Kim, Yong-Hyeon;Shin, Pyung-Woo;Lee, Sang-Jin
    • Journal of the Korean Ceramic Society
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    • v.53 no.5
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    • pp.557-562
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    • 2016
  • Pyrophyllite granule powders for thermal spray coating were successfully prepared through spray drying process. To produce a stable slurry, commercial pyrophyllite powder of $45{\mu}m$ in size was ball-milled for reduction of the size to $2{\sim}3{\mu}m$ and a dispersant was added to control the viscosity. Dense and spherical granules (average granule size : $59{\mu}m$) were prepared under conditions of 12,500 rpm for rotation velocity of the atomizer and 100 cps for slurry viscosity. The granules were then heat treated at $1,200^{\circ}C$ for proper handling strength and flow properties. The final granules had an apparent density of $0.725g/cm^3$ and a flow rate of 2.5 g/sec, which represent excellent properties to be used as the granule powder for thermal spray coatings.

Apparent Amino Acid and Energy Digestibilities of Common Feed Ingredients for Flounder Paralichthys olivaceus

  • Lee, Sang-Min;Seo, Joo-Young;Choi, Kyoung-Hyun;Kim, Kyoung-Duck
    • Journal of Aquaculture
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    • v.21 no.2
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    • pp.89-95
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    • 2008
  • Flounder were fed a reference diet and test diets containing various feed ingredients: mackerel fish meal, meat meal, soybean meal, wheat flour, wheat gluten, corn gluten meal and brewer's yeast. Apparent digestibility was determined using a reference diet with 0.5% chromic oxide indicator and test diets contained 70% reference diet and 30% of the feed ingredient being evaluated. Apparent digestibility coefficients for amino acid and energy in the reference and test diets were determined, and digestibility coefficients for the test ingredients were calculated based on differences in the digestibility of test diets relative to the reference diet. The fish averaging 300 g were held in 2000 L tanks at a density of 20 fish per tank. Feces were collected from three replicate groups of fish using a fecal collection column attached to fish rearing tank. Apparent total amino acids digestibilities(90-95%) of mackerel fish meal, soybean meal, wheat gluten, corn gluten meal and brewer's yeast were higher than those of meat meal and wheat flour(P<0.05). Apparent energy digestibilities(86-98%) of mackerel fish meal, meat meal, soybean meal, wheat gluten and corn gluten meal were significantly higher(P<0.05) than those of wheat flour and brewer's yeast. These results provide useful information about nutrient and energy utilization for flounder.

Physicochemical Properties of Rice-based Expanded Snacks according to Extrusion Conditions (Extrusion 제조 조건에 따른 쌀 스낵 제품의 이화학적 품질특성)

  • Eun, Jong-Bang;Hsieh, Fu-Hung;Choi, Ok-Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.9
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    • pp.1407-1414
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    • 2014
  • Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

The Effect of Chicory Fructan Fiber on Calcium Absorption and Bone Metabolism in Korean Postmenopausal Women

  • Kim, Yun-Young;Jang, Ki-Hyo;Lee, Eun-Young;Yunhi Cho;Kang, Soon-Ah;Ha, Woel-Kyu;Ryowon Choue
    • Nutritional Sciences
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    • v.7 no.3
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    • pp.151-157
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    • 2004
  • The aim of this study was to investigate the effects of chicory fructan fiber supplementation on bone mineral density, apparent absorption of minerals and serum parameters related to bone turnover in postmenopausal women. Twenty-six healthy Korean postmenopausal women participated in the study. 1be participants were randomly divided into two groups in a double-blind parallel design and took one of the supplements for 3 months; either a placebo of 8g maltodextrins/sucrose mixture (control group) or 8g chicory fructan fiber (fructan group). During the 3-month experimental period no differences were found in bone mineral density (BMD) between the two groups. Apparent calcium absorption significantly increased by 42% in the fructan group, while that of the control group decreased by 29% as compared to the values at baseline. Urinary calcium excretion was not significantly different between the group;;. After 3 months, the level of serum alkaline phosphatase (ALP) was significantly lower in the fructan group than in the control group and deoxypyridinolin showed a trend toward a slight reduction. In conclusion, intake of chicory fructan fiber with a regular increases apparent calcium absorption in postmenopausal women.