• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.145-149
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• 2000

We performed the geotechnical experiments of the hydraulic conductivity and compressive strength test with the stabilized soil in the laboratory, proved that it is useful to use the stabilized soil as an alternative for natural clay soil. Also, for mixing adding materials in the stabilized soil, it was determined that 1) the optimal mixing ratio of cement : bentonite : stabilizing agent was 90:60:1 of mass ratio(kg) for 1㎥ with soil, 2) it was also possible to use low quality bentonite(B\circled2) classified by swelling grade because of little difference from results of the hydraulic conductivity and compressive strength test with high quality bentonite(B\circled1). According to the results of the fixation ability of heavy metals(Pb$^{2+}$, Cu$^{2+}$, Cd$^{2+}$, Zn$^{2+}$) with soil and additives, authors can conclude that the higher pH condition had the more removal efficiency of heavy metals. B\circled1 and cement had especially high removal efficiency of heavy metals in a whole pH because of high alkalinity.alinity.

• 대한후두음성언어의학회지
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• 제7권1호
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• pp.11-19
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• 1996

Reinke's edema is used for describing varying degrees of chronic swelling of the vocal folds. The acoustic analysis of Reinke's edema has not been reported so far in this country. The purpose of this study is to clarify acoustic and aerodynamic characteristics of the Reinke's edema. Several acoustic evaluations ＆ aerodynamic studies were done in 20 Reinke's edema patients and the data was compared with those of 20 normal controls. Videolaryngoscopy also was done to classify the severity in grading. We used C-Speech, Doctor speech science, and Phonatory function analyser. In C-Speech, we compared jitter, shimmer, and SNR(signal to noise ratio) of normal and Rrinke's edema patient. In Doctor speech science, we compared NNE(Glottal noise energy), speech fundamental frequency, voice quality between two groups. And in phonatory function analyser for aerodynamic function test, we compared speech intensity, airflow rate, and expiratory pressure between two groups. In conclusion, Reinke's edema patients showed lower voice pitches than normal, additionally jitter, shimmer, SNR(signal to noise ratio), NNE(Glottal noise energy), airflow rate, and expiratory pressure may be meaningful parameters for diagnosis and prognosis for treatment.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 1994년도 정기총회 및 제4차 학술발표회
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• pp.15-16
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• 1994

옥수수 전분의 추출공정 개선 연구의 일환으로 메 밀 찰옥수수에 0-10 kGy범위의 감마선을 조사한 후 전분 추출시험과 추출전분의 이화학적 특성을 펴가하였다. 적정선량 범위의 감마선조사는 전분추출을 위한 침지시간을 기존 50시간에서 40시간으로 단축 시킬 수 있었으며, 환경기준 물질인 옥수수침지액(아황산용액)의 농도를 기존 0.8-1.2% 에서 0.2%로 크게 감소시킬 수 있었다. 또한 옥수수전분 추출액에 있어서 감마선 조사된 메옥수수와 찰옥수수는 비조사군에 비해 10-30% 이상의 추출율 증대효과를 나타내었다. 추 전분의 이화학적 특성시험에있어서는 두 시료 모두 감마선조사에 의해 alkaili number와 광투과도가 크게 증가 하였으며, 물 결합능력 및 swelling power는 다소 감소하는 경향이었다.전분의 색도는 조사군과 비조사군 사이에 유의적인 차이가 없었다. 효소반응 시험에서는 감마선 조사량이 증가함에 따라 효소반응 생성물인 포도당과 환원당 함량이 크게 증가하였다. Amylograph에 의한 물성시험에서는 감마선조사에 의해 전분호화액의 점도는 감소되었고, 그 경향은 메옥수수보다 찰옥수수에서 더욱 현저하였다. 또한 감마선의 이용은 옥수수 전분의 breakdown ratio 및 setback ratio를 향상시킬 수 있어 식품가공에서 전분의 고존도 사입 가능성을 시사하였다. 시사하였다.

• Journal of the Korean Wood Science and Technology
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• 제48권1호
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• pp.22-31
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• 2020

In this study, rice straw and bagasse are used as raw materials to produce binderless particleboard (BPB). This study aims to evaluate the mechanical and physical properties of BPB. We identify the raw material that would be better for the production of BPB from the viewpoint of their basic properties. The BPBs are made from rice straw, bagasse, and combinations of both in ratios of 50:50 and 40:60, respectively. The modulus of elasticity (MOE), modulus of rupture (MOR), internal bonding (IB) strength, water absorption, and thickness swelling properties of the different BPBs are determined and compared. Results showed that all the properties are significantly influenced by the type of particles or particle combinations in the BPB. BPBs made from bagasse alone have the highest MOR, MOE, and IB mean values, whereas BPBs made from rice straw alone exhibit the lowest MOR, MOE, and IB values. Meanwhile, BPBs made from a combination of rice straw and bagasse at 40:60 ratio by weight have the second highest values for properties such as MOR, MOE, and IB, followed by BPBs made from a combination of rice straw and bagasse at 50:50 ratio by weight.

• 환경생물
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• 제36권4호
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• pp.456-462
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• 2018

The purpose of this study was to assess cross-generational effects of bisphenol A exposure in benthic copepods, Tigriopus west. Nauplii (<24 hours old) were exposed to graded concentrations of bisphenol A, and toxicity end-points such as survival, development, sex ratio, and fecundity were measured. $F_1$ generations were grown under innoxious conditions, and similarly assessed. Significant differences were observed in development of nauplii and copepodites, between exposed and non-exposed copepods; however, there were no differences in survival of nauplii or copepodites, sex ratio, or brooding rate in parental generation. In contrast, in the $F_1$ generation, there were significant differences between the control group and exposed group in survival and development of nauplii. Length, width, and biomass of parental and $F_1$ generations were reduced in the exposed group compared to the control group. In addition, some deformities, such as swelling of the prosome, abnormally shaped egg sac, and dwarfism were observed after exposure to bisphenol A. So, our study demonstrates that a cross-generation toxicity test and monitoring of morphological deformities in harpacticoid copepods, can be useful for development of potential bioindicators for environmental monitoring, and assessment of chemical impact.

• Elastomers and Composites
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• 제54권3호
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• pp.225-231
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• 2019

Bio-based polyester polyol was synthesized via esterification between azelaic acid and isosorbide. After esterification, bio-based polyurethanes were synthesized using polyester polyol, 1,3-propanediol as the chain extender, and 4,4'-diphenylmethane diisocyanate, in mixing ratios of 1:1:1.5, 1:1:1.8, 1:1:2, and 1:1:2.3. The bio TPU (Thermoplastic Polyurethane) samples were characterized by using FT-IR (Fourier Transform Infrared Spectroscopy), TGA (Thermal Gravimetric Analysis), DSC (Differential Scanning Calorimetry), and GPC (Gel Permeation Chromatography). The mechanical properties (tensile stress and hardness) were obtained by using UTM, a Shore A tester, and a Taber abrasion tester. The viscoelastic properties were tested by an Rubber Processing Analyzer in dynamic strain sweep and dynamic frequency test modes. The chemical resistance was tested with methanol by using the swelling test method. Based on these results, the bio TPU synthesized with the ratio of 1:1:2.3, referred to as TPU 4, showed the highest thermal decomposition temperature, the largest molecular weight, and most compact matrix structure due to the highest ratio of the hard segment in the molecular structure. It also presented the highest tensile strength, the largest elongation, and the best viscoelastic properties among the different bio TPUs synthesized herein.

• Journal of Forest and Environmental Science
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• 제14권1호
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• pp.138-144
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• 1998

표고폐골목의 재활용을 목적으로 폐골목과 정상재의 칩을 일정비율로 혼합하여 얻은 목질보드의 성질을 조사, 검토하였다. 그 결과 폐골목의 목섬유는 정상재보다 다소 짧고 표면이 거철었으며 폐골목 변재부의 밀도는 정상재에 비해 상당히 낮았다. 파티클보드의 두께 팽윤율 및 파괴계수의 시험결과 폐골목을 25-50% 정도 혼합한 경우는 정상재와 비슷한 값을 나타냈다. 결론적으로 폐골목은 파티클보드의 재료로 사용될 수 있고 정상재와의 혼합비율은 25~50% 범위에서 조정되어야 할 것으로 생각되었다.

• Journal of Microbiology and Biotechnology
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• 제27권4호
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• pp.747-758
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• 2017

Chronic wounds, pressure sores, lesions, and infections of microbial origin in bedridden, paralyzed, or malnutrition patients remain the object of study of many researchers. A variety of factors behind the development of these disorders are related to the patient's immune system, making it unable to respond effectively to the treatment of the wound. These factors can be properly controlled, giving particular importance to the ethiology and stage of the wound, as well as the time periods corresponding to the replacement of the dressings. The present research reports a novel foam/soft material, ${{\small}L}$-Cys-g-PCL, with an application for decubitus/pressure ulcers, especially for wounds with a difficult healing process due to infections and constant oxidation of the soft tissues. During this work, the interactions between S. aureus and ${{\small}L}$-Cys-g-PCL foam were studied under conditions that simulate decubitus ulcers; namely, pH and exudate. The effects of duration of grafting (1 or 8 h) and pH (7.0 and 8.9) on wettability, surface energy, swelling, and porosity were also evaluated. Results showed an effective microbicidal activity exhibiting an inhibition ratio of 99.73% against S. aureus. This new ${{\small}L}$-Cys-g-PCL soft material showed saftey to contact skin, ability to be shaped to fill in sunken holes (craters) - pressure ulcers stage III - and to act as a smart material responsive to pH, which can be tailored to develop better swelling properties at alkaline pH where exudates are normally higher, so as to address exudate self-cleaning and prevention of desiccation.

• 폴리머
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• 제27권4호
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• pp.349-357
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• 2003

생체 적합성이 우수한 폴리(비닐 알코올)(PVAL)과 폴리(N-비닐 피롤리돈)(PVP), 항균성이 있는 헥실렌글리콜 (HG)과 치료효과가 우수한 수용성 키토산을 혼합하여 상처치료용 수화젤을 제조하였다. 제조 방법으로 수용액의 동결과 융해에 의한 물리적 가교, 방사선 조사에 의한 화학가교 및 동결과 융해의 물리적 가교 후 방사선 가교를 이용하였다. 수화젤 제조시 PVAL/PVP/HG/키토산의 농도는 15 wt%, 키토산은 0.3wt%, PVAL과 PVP의 비는 6:4로 고정하였다. 용액내 HG의 농도를 1∼5 wt%로 변화시켰으며, 동결과 융해횟수는 1∼3회로 변화시켰고, 방사선 조사량은 25∼50 kGy로 변화시켰다. 위의 방법으로 제조된 수화젤의 젤화율, 팽윤도, 젤강도를 측정하였다. HG의 조성비가 증가할수록 젤화율과 젤강도는 감소하였고 팽윤도는 증가하였다. 조사량과 동결과 융해 횟수가 증가할수록 젤화율과 젤강도는 증가하였고 팽윤도는 감소하였다. 동물 실험을 통해 제조된 수화젤의 상처 치료효과를 보았으며, 항균 실험을 통해 항균성을 관찰하였다.

• 한국식품조리과학회지
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• 제13권4호
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• pp.379-383
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• 1997

아밀로오스 함량이 다른 옥수수 전분을 121$^{\circ}C$에서 호화시켜 팽윤력과 용해도를 측정했을때, 팽윤력은 찰옥수수 전분인 Amioca가 가장 컸고, PFP, Amaizo, Amylomaize VII 순이었으며 Amaizo의 경우 용출된 겉보기 아밀로오스의 요드 친화력이 가장 높았고, 용해도 역시 높게 나타났다. BrooHield viscometer를 이용하여 0.25 N NaOH 용액으로 측정한 알칼리 호화양상은 Amylomaize VII이 최고점도 l0$\times$$10^3$cp를 나타낸 반면 Amaizo는 70$\times$$10^3$cp로 Amylomaize VII에 비해 높은 값을 나타냈고, PFP는 70$\times$$10^3$cp까지 증가했다가 감소하였다. 전분과 물을 1 : 9로 하여 121$^{\circ}C$에서 가열-냉각 횟수를 4회 반복하며, 각 단계에서 형성된 겔의 성질을 비교하면 Amaizo로 만든 겔의 견고성, 부착성, 탄성과 응집성이 가장 컸으며, 견고성은 가열-냉각처리를 2회 반복한 경우 가장 컸고 그 후 감소하였다. 옥수수전분 겔의 성질은 아밀로오스 함량보다는 사슬길이나 가열 중 용출되는 부분의 성질에 더 상관성이 높았다.