• Title/Summary/Keyword: chemical quality

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Trends in System-level Research on Quality Control of Complex Herbal Formulation (복합 처방 품질 관리를 위한 시스템 차원의 연구 동향)

  • Lee, Doo Suk;Kim, Young Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.30 no.6
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    • pp.397-401
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    • 2016
  • The quality control is a fundamental procedure for the standardization of herbal medicine to guarantee the consistency of efficacy and safety. For a long time, the quality analysis of herbal medicine has been largely dependent on the routine sensory evaluation, such as taste, smell, color, and shape. However, with the recent development of analytical instruments, various scientific approaches have been introduced in this field. On the basis of the theory that the biological activities of herbal medicine are mainly contributed by its chemical compositions, several types of chemical markers have been suggested for the quality evaluation. In addition to the analytical methods for the specific marker compound(s), including analytical marker and active marker, recently, chemical fingerprinting, a method comparing the chromatographic pattern of the whole chemical components, has been developed and widely accepted as a reliable approach for the quality control of herbal medicine. Moreover, in order to exactly understand the relationship between complex compounds and their holistic biological activities in herbal medicine, unique strategies, such as "BECCs (bioactive equivalent combinatorial components)" and "PhytomicsQC" have been established. In this article, we give an overview of the several categories of chemical markers and the recent research trends for the quality evaluation of herbal medicine.

Calculating Soil Quality Index for Biomass Production Based on Soil Chemical Properties

  • Kim, Sung-Chul;Hong, Young Kyu;Lee, Sang Phil;Oh, Seung Min;Lim, Kyung Jae;Yang, Jae E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.50 no.1
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    • pp.56-64
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    • 2017
  • Soil quality has been regarded as an important factor for maintaining sustainability of ecosystem. Main purpose of this research was i) to select minimum factor for predicting biomass, and ii) to calculate soil quality index for biomass according to soil chemical properties. Result showed that soil pH, electrical conductivity (EC), soil organic matter (SOM), cation exchange capacity (CEC), and available phosphorus are minimum data set for calculating biomass production in soil. Selected representative soil chemical properties were evaluated for soil quality index and rated from 1 to 5 (1 is the best for biomass production). Percentage of each grade in terms of biomass production in national wide was 14.52, 35.23, 33.03, 6.47, 10.75% respectively. Although, only soil chemical properties were evaluated for calculating optimum soil quality, result of this research can be useful to understand basic protocol of soil quality assessment in national wide.

The Freezing Temperature of Chemical Admixtures for Concrete and the Quality Vareation of Concrete Using the Frozen Admixtures (콘크리트용 혼화제의 동결온도 및 동결된 혼화제의 사용에 따른 콘크리트의 품질변화)

  • 한천구;한경익;이건철
    • Magazine of the Korea Concrete Institute
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    • v.10 no.4
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    • pp.205-212
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    • 1998
  • Frost damage of a storage tank for chemical admixtures caused by a low temperature in winter and quality deterioration of chemical admixtures have been often reported. However, there have been few regulations and researches related to the frost damage of chemical admixtures and facilities. Therefore, this paper is intend to investigate not only, the freezing points of chemical admixtures such as AE admixtures and water-reducing AE admixtures, etc., but also the quality variation of concrete used with chemical admixtures before freezing and after freeze-thaw cycles. According to the results of experiments, most chemical admixtures except anti-freezing agent and accelerating water-reducing AE admixtures should be kept from being frozen in low winter temperatures. However, full agitation of frozen chemical admixtures dose not cause the problems of concrete related to the quality of chemical admixtures.

ISO 9000 Registration in Chemical Industry: Problems, Solutions and Case Studies (화학산업에서의 ISO 9000인증 : 문제점과 대책 및 사례)

  • Lee, Kwan-Suk;Lee, Moon-kyu
    • Journal of Korean Society for Quality Management
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    • v.23 no.1
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    • pp.106-114
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    • 1995
  • The chemical industry has been a leader in the number of registrations for many decades. The big chemical companies in Korea were clearly committed to ISO 9000 and had strong senior management support. However, not many people in the chemical industry are familiar with ISO 9000 and understand how to develop a ISO 9000 quality manual and how to organize a campaign to get the ISO 9000 registration. The purpose of this paper is to briefly summarize the key concerns of chemical companies and how companies can address those concerns and conform to the various elements of the ISO 9000 standards. The case studies of two domestic and foreign companies in establishing ISO 9000 quality system are also discussed.

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A Study on the Chemical Admixture According to Target Slump Value by Crushed Sand Replacement Rate (부순모래 치환율별 목표슬럼프 값 고정에 따른 화학혼화제의 특성에 관한 연구)

  • Ryu, Hyun-Gi;Cho, Myeong-Ken
    • Journal of the Korea Institute of Building Construction
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    • v.8 no.4
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    • pp.87-93
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    • 2008
  • With an increased use of alternative aggregate due to exhaustion of quality aggregate resources, the amount of used crushed aggregates have been increased and as a result, development of admixture materials has also been improved and its amount of use is increasing from day to day in order to secure quality in concrete. Accordingly, the purpose of this study is to make concrete of good quality by using chemical admixture developed in this study by replacement rate of fine aggregate. At first, susceptibility, compressive strength ratio and length change ratio in both fresh and hardened concrete were evaluated according to corresponding regulation. As for high performance related regulation, APC NO.3 and PC series were going to rule, and as for AE agent regulation, replacement ratio of fine aggregate of high performance chemical admixture was 10:0 and other chemical admixture met quality regulation for AE agent.

Optimal Learning Control Combined with Quality Inferential Control for Batch and Semi-batch Processes

  • Chin, In-Sik;Lee, Kwang-Soon;Park, Jinhoon;Lee, Jay H.
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.57-60
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    • 1999
  • An optimal control technique designed for simultaneous tracking and quality control for batch processes. The proposed technique is designed by transforming quadratic-criterion based iterative learning control(Q-ILC) into linear quadratic control problem. For real-time quality inferential control, the quality is modeled by linear combination of control input around target qualify and then the relationship between quality and control input can be transformed into time-varying linear state space model. With this state space model, the real-time quality inferential control can be incorporated to LQ control Problem. As a consequence, both the quality variable as well as other controlled variables can progressively reduce their control error as the batch number increases while rejecting real-time disturbances, and finally reach the best achievable states dictated by a quadratic criterion even in case that there is significant model error Also the computational burden is much reduced since the most computation is calculated in off-line. The Proposed control technique is applied to a semi-batch reactor model where series-parallelreactions take place.

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Effect of Mower Conditioner and Chemical Dry Agents on the Field Drying Rate of Mixed Pasture Plants Hay (Mower Conditioner와 건조제 처리에 의한 속성 양질 혼파목초 건초조제 효과)

  • Seo, S.;Chung, E.S.;Kim, J.G.;Kim, W.H.;Kang, W.S.;Lee, H.W.
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.18 no.3
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    • pp.259-266
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    • 1998
  • A field experiment was carried out to determine the effects of mechanical and chemical drying agents at mowing on the field drying rate and hay quality of orchardgrass dominant pasture plants. The mower conditioner /chemical drying agent ($K_2CO_3$ 2% conditioning, $K_2CO_3$ 2% + conditioning and control) were treated at different harvest stages (late boot, heading and bloom stage) for hastening hay manufacture in 1996. After field dry, four square bales were made by hay baler, and the visual estimation and nutritive value of hay were evaluated after storing two months. The field drying rate of pasture plants was higher with delayed stage of harvest, and mechanical and mechanical + chemical, but chemical alone was very low. In mower conditioning, the duration of field dry was shortened by 0.5 to 1 day compared with $K_2CO_3$ and 1.5 to 2 days compared with control. The dry matter loss of hay was reduced by late harvest and mechanical, and mechanical + chemical, but the score by chemical alone was very low. The visual score (leafiness, green color, odor and softness) of hay after storage was high in mechanical and mechanical + chemical, but the score by chemical alone was very low. Nutritive value (ADF, NDF, digestibility, and relative feed value) of hay was also high with treatment of mechanical and mechanical + chemical, but the quality by chemical alone was similar compared with control. The quality of hay was very low when harvested at bloom stage. In conclusion, mower conditioning can enhance the field drying rate of orchardgrass dominant pasture plants, however the drying efficiency of chemical drying agent was very low. Harvesting at early heading to heading stage was recommened for manufacture of high quality hay.

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Responses of Low-Quality Soil Microbial Community Structure and Activities to Application of a Mixed Material of Humic Acid, Biochar, and Super Absorbent Polymer

  • Li, Fangze;Men, Shuhui;Zhang, Shiwei;Huang, Juan;Puyang, Xuehua;Wu, Zhenqing;Huang, Zhanbin
    • Journal of Microbiology and Biotechnology
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    • v.30 no.9
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    • pp.1310-1320
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    • 2020
  • Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg-1 super absorbent polymer, 3 g·kg-1 humic acid, and 10 g·kg-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

EVALUATION OF NIRS FOR ASSESSING PHYSICAL AND CHEMICAL CHARACTERISTICS OF LINEN WEFT YARN

  • Sharma, Hss;Kernaghan, K.;Whiteside, L.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1091-1091
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    • 2001
  • Previous reports have shown that Near Infrared Spectroscopy (NIRS) can be used to assess physical and chemical properties of flax fibre and fabric quality. Currently, spinners assess yarn quality mainly based on strength and regularity measurements. There two key characteristics are influenced by quality of raw fibres used, especially the degree of rotting and strength. The aim of this investigation was to evaluate the use of NIRS for assessing quality of weft grade yarn available on the commercial market. In order to develop the NIR calibrations, a range of samples representing poor, medium and good quality weft yarn samples was included in the calibration and validation sample sets. The samples were analysed for physical and chemical parameters including caustic weight loss, fibre fractions, lipid, ash and minerals. A detailed protocol for assessing yarn quality has been developed to maximize the accuracy of the reflectance spectra. The development of partial least squares regression models and validation of the calibration equations using blind samples will be presented and discussed.

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Determination of Toxic Elements in Polymer Materials Using Instrumental Neutron Activation Analysis

  • Park, Kwang-Won;Lee, Joung-Hae;Cho, Kyung-Haeng;Min, Hyung-Sik;Lim, Myung-Chul;Choi, Duk-Soo
    • Bulletin of the Korean Chemical Society
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    • v.29 no.7
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    • pp.1391-1394
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    • 2008
  • Polymer materials are very difficult to decompose for the purpose of chemical analysis. Nondestructive analysis without pretreatment provides a suitable solution that will overcome this obstacle. In this study, CRM candidate samples that contained toxic elements such as As, Cd, Cr and Zn in a polypropylene (PP) were analyzed using instrumental neutron activation analysis (INAA). The analytical results were obtained from ten samples selected by random sampling at two different concentration levels (low and high). Particular attention was paid to reducing analytical errors and evaluating the associated uncertainty.