• Title/Summary/Keyword: drying period

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Effect on the corrosion of steel by unburnt carbon in fly ash cement mortar (미연탄소분이 플라이 애시 시멘트 모르타르내 철근의 부식에 미치는 영향)

  • Ha, Tae-Hyun;Bae, Jeong-Hyo;Lee, Hyun-Goo;Kim, Dae-Kyeong;Ha, Yoon-Cheol
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1416-1417
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    • 2006
  • The increase of carbon contents in fly ashes accelerate the corrosion of steel embedded in ordinary portland cement mortar. Cement losses its identity of colour, when the % of carbon is increased. More than 60[%] area was rusted, when carbon content is increased beyond 8[%] for the exposure period of one year. Comparable corrosion rate with OPC was obtained up to 6[%] carbon level only. The tolerable limit of replacement for various admixed carbon system under aggressive alternate wetting and drying condition with 3[%] NaCl was found to be 6 to 8[%].

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Determination of the water content in Citrus leaves by portable near infrared (NIR) system

  • Suh, Eun-Jung;Lim, Hun-Rang;Woo, Young-Ah;Kim, Hyo-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.405.1-405.1
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    • 2002
  • The amount of water for the cultivation of citrus is different based on the growing period. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine non-destructively the water content of Citrus leaves by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from satsuma mandarin leaves (Citrus unshiu Marc. var. okitsu) ranging from 62.20 to 69.98% of water content by loss on drying, NIR reflectance spectra of Citrus leaves were acquired by using a fiber optic probe. (omitted)

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The Characteristics of the Change in dry Contraction Length of Dry Mortar for Each Cosmetic Period using an Improved Durometer (개량형 Durometer를 활용한 미장시기별 Dry Mortar의 건조수축 길이변화 특성)

  • Han, Soo-Hwan;Hyun, Seung-Yong;Hwang, Yin-seung;Yoon, Chi-Whan;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.190-191
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    • 2021
  • This study is conducted to provide a method to estimate the setting time and early age compressive strength using D type durometer.Test results indicated that the use of D type Durometer attached with modified needle, which was designed to secure improved accuracy in setting and compressive strength, enables to estimate setting time and the compressive strength at early age.

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Formulation and Evaluation of Sustained Release Preparation of Ibuprofen Fast-Disintegrating Tablet (FDT)

  • Kim, Kwang-Hyeon;Park, Jun-Bom;Kang, Joo-Hyung;Lee, Kun-Hee;Kang, Chin-Yang
    • Journal of Pharmaceutical Investigation
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    • v.41 no.1
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    • pp.51-57
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    • 2011
  • The objective of this study was to enhance the utilitization of Ibuprofen (IBU) by introducing the fast-disintegrating tablet (FDT) form. Presently, IBU is being widely used as a tablet or syrup form. But in contrast to these two formulations, IBU as FDT is not only convenient but also increases the control over the time release of the drug, noted by using Alginate beads. This study was carried out with Sodium Alginate and IBU at the ratios of 1:0, 1:0.5, 1:1, and 1:2 in order to produce a series of beads with different ratios. During the drying process of the beads, talc was added in beads to compare the effects with and without the talc. The final product was scanned with SEM imaging to determine the difference in the surface of the beads. The parameters assessed were the diameter, content assay, dissolution test and effectiveness of time-release. Direct compression method was used to prepare FDT containing IBU bead. The properties of FDT, such as hardness, disintegration time, were investigated. The dissolution profiles of FDT were tested using KP dissolution apparatus 1 (basket method). The results suggest addition of talc and drying the beads made the surface smooth and less vulnerable to clutter into chunks. The size of beads was less than 300 ${\mu}m$ which did not create a sandy feeling in the mouth. Thus, the beads formulation model made the sustained release of the drug possible, the hardness of FDT (1.25~1.50 $Kg/cm^2$) was acceptable and all the values of dissolving period were less than 30 seconds. The dissolution profile of FDT was same as that of IBU bead. The efficient dissolution profile and low price of IBU bead containing Sodium Alginate, the FDT formulation prepared from IBU bead can save the expenses and can improve the convenience of application of this drug.

A Comparative Study of CG CryoDerm and AlloDerm in Direct-to-Implant Immediate Breast Reconstruction

  • Lee, Jun Ho;Park, Ki Rin;Kim, Tae Gon;Ha, Ju-Ho;Chung, Kyu-Jin;Kim, Yong-Ha;Lee, Soo Jung;Kang, Soo Hwan
    • Archives of Plastic Surgery
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    • v.40 no.4
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    • pp.374-379
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    • 2013
  • Background To date, various types of acellular dermal matrix (ADM) have been developed for clinical use. AlloDerm is the most familiar type of ADM to most surgeons in breast reconstruction. It is prepared by freeze-drying. CG CryoDerm is the first form of ADM that requires no drying process. Therefore, theoretically, it has a higher degree of preservation of the dermal structures than AlloDerm. We conducted this study to compare the clinical course and postoperative outcomes of patients who underwent direct-to-implant breast reconstructions using AlloDerm and those who did using CG CryoDerm. Methods We performed a retrospective analysis of the medical records in a consecutive series of 50 patients who underwent direct-to-implant breast reconstruction using AlloDerm (n=31) or CryoDerm (n=19). We then compared the clinical course and postoperative outcomes of the two groups based on the overall incidence of complications and the duration of drainage. Results The mean follow-up period was 16 months. There were no significant differences in the overall incidence of complications (seroma, infection, skin flap necrosis, capsular contracture, and implant loss) between the two groups. Nor was there any significant difference in the duration of drainage. Conclusions CG CryoDerm has the merits of short preparation time and easy handling during surgery. Our results indicate that CG CryoDerm might be an alternative allograft material to AlloDerm in direct-to-implant breast reconstruction.

The Effect of the Different Time Period between the Fermentation and the Freeze-drying on Protein Efficiency Ratios of Candida utilis (Single Cell Protein(Candida utilis)에 있어서 Fermentation과 Freeze-Drying과정 사이의 시간 차이가 Protein Efficiency Ratio에 미치는 영향)

  • Shin, Hyun-Hee
    • Journal of Nutrition and Health
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    • v.12 no.2
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    • pp.87-93
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    • 1979
  • 인구적 증가와 사료 가격의 상승으로 인한 육류 제품의 가격이 상승하고 있음은 우리나라를 비롯하여 세계적인 현황이다. 이 문제에 대처하는 한 방법으로 새로운 단백질 급원으로써 Single Cell Protein이 개발되었고 이에 대한 여러가지 연구가 되어지고 있다. Single Cell Protein이 인간에게 식용이 될 동물이나 나아가서는 인간에게 직접 식품으로 사용되기 전에 인체나 동물 체내에 끼칠 영향과 그 안전성을 확인하려는 하나의 노력으로 이 연구가 시도되었다. 동물 체내 대사에 미치는 SCP의 악영향의 주원인은 함유된 독성물질로 보고 그 독성물질이 SCP 생산 및 처리 과정 중 어느 시기에 생겨나는가를 규명해 보고자 하였다. Fermentation을 끝낸 SCP의 Supernatant내에 함유된 Inorganic phosphate(I.P.)의 함량을 측정하여 SCP세포의 Viability를 알아보았다. Fermentation을 끝낸 후 10일까지는 I.P.가 차츰줄다가 40일이 지났을 때에는 I.P.의 증가를 보였으나 직후보다는 낮음을 나타냈다. 또한 냉동 건조시킨 뒤에도 SCP Cell이 살아있음을 보였다. 또한 위와 관련지어서 SCP를 Protein급원으로 써서 사육한 흰쥐에 나타난 Protein Efficiency Ratio(PER)를 통하며 SCP의 질을 평가하였다. 실험결과로 나타난 것을 보면 표준 식이에 사용된 Casein의 PER$(\overline{X}=2.58)$이 SCP의 PER$(Dict 1;\overline{X}=0.888$, $Dict 2;\overline{X}=0.893$, $Dict 3;\overline{X}=0.860)$ 보다 유의적으로 높았다. 그리고 총실험기간의 평균치를 볼 때, Fermentation을 끝내고 3일 후와 6일 후에 냉동 건조시킨 SCP의 PER은 시판되는 SCP의 것과 별다른 차이를 보이지 않았다. 그리나 후반기에 있어서는 Fermentation을 끝내고 3일과 6일 후에 냉동 건조시킨 SCP의 PER이 시판되는 SCP의 것보다 약간 저조함을 보였다. 그리고 Casein의 PER은 총 사육기간은 통하여 별 변동이 없음에 반하여 후반기에 SCP의 PER이 급격한 저하를 보임은 SCP 사용상의 문제점을 나타낸 것으로 해석 된다.

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Evaluating the Effectiveness of Cryopreserved Acellular Dermal Matrix in Immediate Expander-Based Breast Reconstruction: A Comparison Study

  • Kim, So-Young;Lim, So Young;Mun, Goo-Hyun;Bang, Sa-Ik;Oh, Kap Sung;Pyon, Jai-Kyong
    • Archives of Plastic Surgery
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    • v.42 no.3
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    • pp.316-320
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    • 2015
  • Background CGCryoDerm was first introduced in 2010 and offers a different matrix preservation processes for freezing without drying preparation. From a theoretical perspective, CGCryoDerm has a more preserved dermal structure and more abundant growth factors for angiogenesis and recellularization. In the current study, the authors performed a retrospective study to evaluate freezing- and freeze-drying-processed acellular dermal matrix (ADM) to determine whether any differences were present in an early complication profile. Methods Patients who underwent ADM-assisted tissue expander placement for two stage breast reconstruction between January of 2013 and March of 2014 were retrospectively reviewed and divided into two groups based on the types of ADM-assisted expander reconstruction (CGDerm vs. CGCryoDerm). Complications were divided into four main categories and recorded as follows: seroma, hematoma, infection, and mastectomy skin flap necrosis. Results In a total of 82 consecutive patients, the CGCryoDerm group had lower rates of seroma when compared to the CGDerm group without statistical significance (3.0% vs. 10.2%, P=0.221), respectively. Other complications were similar in both groups. Reconstructions with CGCryoDerm were found to have a significantly longer period of drainage when compared to reconstructions with CGDerm (11.91 days vs. 10.41 days, P=0.043). Conclusions Preliminary findings indicate no significant differences in early complications between implant/expander-based reconstructions using CGCryoderm and those using CGDerm.

Effects of Seed Pretreatment and Environment Controls on Germination of Atractylodes japonica Seeds (종자 전처리 및 환경조절이 삽주 종자 발아에 미치는 영향)

  • Jeon, Kwon Seok;Song, Ki Seon;Yoon, Jun Hyuck;Kim, Chang Hwan;Kim, Jong Jin
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.5
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    • pp.394-400
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    • 2013
  • This study was carried out in order to examine the germination characteristics of Atractylodes japonica seeds, and it was to develop the more efficient pre-treatment and production system of the seeds. Experiment was performed by two ways-temperature control (10, 15, 20, $25^{\circ}C$) and shading treatment (full sunlight, 35, 50, 75, 95% of full sunlight). Seed pre-treatment before the each experiment was carried out by temperature (with low temperature and wetting treatment (LTW) for 0, 15, 30, 45 and 60 days) and shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 48 hours). Seeds of A. japonica were germinated well under temperature control (overall 85.3~100%), especially high temperature. And, the seeds pre-treated with LTW for 45 days germinated with a 100% success rate. Under the surveying shading treatment, the highest germination rate was 95.8% with DRT and overall 63.2~95.8%. Germination rate under seeds with WS was 63.2~7.8%. As a result of surveying the whole experiment, A. japonica seeds don't need to pre-treat cause of high germination, but if it is performed with LTW for a certain period of time, it would be more productive.

Study on Cracking Causes and Patterns in Median Barrier and Guardrail Concrete in RC Bridge (콘크리트 교량 방호벽의 균열원인 및 패턴 분석에 대한 연구)

  • Choi, Se-Jin;Choi, Jung-Wook;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.18 no.5
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    • pp.19-26
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    • 2014
  • Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.