• 환경위생공학
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• 제23권4호
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• pp.1-11
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• 2008

The goal of today's environmental education is to enhance the understanding of the serious of environmental problems and the interactions among environment. With this perspectives people need to be aware that environmental education is no longer a liberal arts in university education, but play a vital role within the socio-cultural context. This study was performed to assess the changes in the university student's attitudes and consciousness in real life after the education of a point at issues of environmental problems. For this study 11 questionnaires which were composed of large scale environmental problems(water and air pollution), and small scale environmental problems(food additives, GMO, endocrine disrupter) were performed with self-administered by university students(n=781) who made a application for liberal arts related to environmental subjects. According to the analysis the most student's consciousness of a point at issue of environmental problems(water pollution, air pollution, additives, GMO, endocrine disrupter), and practical attitudes(i.e., practical attendant at congregation and internet voting) were change statistically significant(p<0.01) after the education of a point at issue of environmental problems rather than before. Specially, the score for the item of the large scale problem of environmental issues(water pollution, air pollution) were decreased significantly(p<0.01), but the score for the small scale problems, such as food additives, GMO, endocrine disrupter were increased significantly(p<0.01) after the education of a point at issue of environmental problems(p<0.01). And among the students that participated, 97.7% responded that such a point at issues of environmental problem is needed at the university. With this educational improvements supports the states that the education of a point at issue of environmental problems were more essential, practical and needed to students at university rather than that of an existing instruction. Thus, further studies are required to develop the education of environmental issues at universities like STSE programme.

• Journal of Animal Science and Technology
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• 제65권5호
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• pp.895-911
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• 2023

Processed meat products play a vital role in our daily dietary intake due to their rich protein content and the inherent convenience they offer. However, they often contain synthetic additives and ingredients that may pose health risks when taken excessively. This review explores strategies to improve meat product quality, focusing on three key approaches: substituting synthetic additives, reducing the ingredients potentially harmful when overconsumed like salt and animal fat, and boosting nutritional value. To replace synthetic additives, natural sources like celery and beet powders, as well as atmospheric cold plasma treatment, have been considered. However, for phosphates, the use of organic alternatives is limited due to the low phosphate content in natural substances. Thus, dietary fiber has been used to replicate phosphate functions by enhancing water retention and emulsion stability in meat products. Reducing the excessive salt and animal fat has garnered attention. Plant polysaccharides interact with water, fat, and proteins, improving gel formation and water retention, and enabling the development of low-salt and low-fat products. Replacing saturated fats with vegetable oils is also an option, but it requires techniques like Pickering emulsion or encapsulation to maintain product quality. These strategies aim to reduce or replace synthetic additives and ingredients that can potentially harm health. Dietary fiber offers numerous health benefits, including gut health improvement, calorie reduction, and blood glucose and lipid level regulation. Natural plant extracts not only enhance oxidative stability but also reduce potential carcinogens as antioxidants. Controlling protein and lipid bioavailability is also considered, especially for specific consumer groups like infants, the elderly, and individuals engaged in physical training with dietary management. Future research should explore the full potential of dietary fiber, encompassing synthetic additive substitution, salt and animal fat reduction, and nutritional enhancement. Additionally, optimal sources and dosages of polysaccharides should be determined, considering their distinct properties in interactions with water, proteins, and fats. This holistic approach holds promise for improving meat product quality with minimal processing.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.479-489
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• 2023

Livestock production depends on the utilization of nutrients, and when this is accomplished, there is accelerated momentum toward growth with a low cost-to-feed ratio. Public concern over the consumption of pork with antibiotic residues in animals fed antibiotic growth promoters (AGP) has paved the way for using other natural additives to antibiotics, such as herbs and their products, probiotics, prebiotics, etc. Numerous feed additives are trending to achieve this goal, and a classic example is vitamins and minerals. Vitamins and minerals represent a relatively small percentage of the diet, but they are critical to animal health, well-being, and performance; both play a well-defined role in metabolism, and their requirements can vary depending on the physiological stage of the animals. At the same time, the absence of these vitamins and minerals in animal feed can impair the growth and development of muscles and bones. Most commercial feeds contain vitamins and trace minerals that meet nutrient requirements recommended by National Research Council and animal feeding standards. However, the potential variability and bioavailability of vitamins and trace elements in animal feeds remain controversial because daily feed intake varies, and vitamins are degraded by transportation, storage, and processing. Accordingly, the requirement for vitamins and minerals may need to be adjusted to reflect increased production levels, yet the information presented on this topic is still limited. Therefore, this review focuses on the role and function of different sources of minerals, the mode of action, the general need for micro and macro minerals in non-ruminant diets, and how they improve animal performance.

• 전기화학회지
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• 제6권4호
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• pp.242-249
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• 2003

아연 전극은 고농도의 KOH전해질 용액의 알카리 전지용 양극재료로 폭넓게 이용되고 있다. 그러나 급속한 전기화학적 반응과 높은 용해도에 의한 수지상의 생성에 의해 사이클 수명이 현저하게 짧아지는 것으로 알려져 있다. 본 연구에서는 용액온도 $25^{\circ}C$의 $40wt.\%$ KOH 전해질에 $Ca(OH)_2$, Citrate, Tartrate 및 Gluconate 등의 첨가제를 첨가하고 그리고 $Pb_3O_4\;5wt\%$를 아연 전극에 혼합하였을 때 아연 전극의 전기화학적 거동에 미치는 Pb,04와 첨가제의 효과를 동전위 분극 곡선, 순환전위전해분석법, 가속수명시험 및 SEM사진 분석을 통하여 고찰하였다. $Pb_3O_4$의 첨가는 아연 전극의 부식 속도를 확실히 감소시키는 효과가 있었으며 그리고 $Pb_3O_4$의 첨가에 의한 아연 전극의 부식 전위는 순수아연 전극에 비하여 다소 높았으나 개로 전압에는 거의 영향이 없었다. 그리고 4가지 종류의 첨가제는 내식성과 가속 수명시험시의 사이클 수명을 향상시키는 데 중요한 역할을 하고 있는 것으로 확인되었다. 더욱이 Tartrate 첨가는 4가지 종류의 첨가제 중에서 상대적으로 충방전 특성을 개선할 뿐 아니라 양호한 내식성 효과가 확인되었다.

• 한국가금학회지
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• 제39권1호
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• pp.33-37
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• 2012

One of the biggest challenges for the animal feed industry in the coming years will be to meet the growing demand in animal protein in light of increased cost of feed ingredient as well as tougher restrictions on the use of antimicrobial growth promoters imposed by consumers and governments. A key focus area will be to maximise feed efficiency and minimise nutrient waste. It has been widely acknowledged that the composition of the intestinal microflora is closely related to intestinal health and performance of animals. Advanced microbial techniques have shown a close relationship between bacterial communities and their ability to modulate nutrient absorption and processing. In addition it has been recognised that modulating the immune response has significant impact on overall health as well as overall nutrient demand. Molecular techniques are a useful tool to gain an understanding of the impact of dietary interventions including the use of functional feed additives on specific changes in microbial communities or the immune system. Most these techniques however focus on the evaluation of large changes in bacterial compositions and often underestimate or neglect to recognise small changes in microbial diversity or behaviour changes without any measurable immune response. The key to understanding the relationship between specific nutritional intervention and the impact on health and performance lies in a deeper understanding of the impact of these nutrients on the expression of specific genes or specific metabolic pathways. The development of molecular tools as a result of developments in the field of Nutrigenomics has enabled researchers to study the effects of specific nutrients on the whole genome or in other words, the effect of thousands of genes simultaneously, and has opened a completely different avenue for nutritional research.

• 한국대기환경학회지
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• 제20권6호
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• pp.783-792
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• 2004

In this study, a thick-film semiconductor odor gas sensor for the detection of $CH_3$SH was developed using SnO$_2$ as the main substrate and was investigated in terms of its sensitivity and reaction time. In the process of manufacturing the sensor, Taguchi's design of experiment (DOE) was applied to analyze the effects of a variety of parameters, including the substrate, the additives and the fabrication conditions, systematically and effectively. Eight trials of experiments could be possible using the 27 orthogonal array for the seven factors and two levels of condition, which originally demands 128 trials of experiments without DOE. The additives of Sb$_2$O$_{5}$ and PdCl$_2$ with the H$_2$PtCl$_{6}$ ㆍ6$H_2O$ catalyst were appeared to be important factors to improve the sensitivity, and CuO, TiO$_2$, V$_2$O$_{5}$ and PdO were less important. In addition, TiO$_2$, V$_2$O$_{5}$ and PdO would improve the reaction time of a sensor, and CuO, Sb$_2$O$_{5}$, PdCl$_2$ and H$_2$PtCl$_{6}$ㆍ6$H_2O$ were negligible. Being evaluated simultaneously in terms of both sensitivity and reaction time, the sensor showed the higher performance with the addition of TiO$_2$ and PdO, but the opposite results with the addition of CuO, V$_2$O$_{5}$, Sb$_2$O$_{5}$ and PdCl$_2$. The amount of additives were superior in the case of 1% than 4%. H$_2$PtCl$_{6}$ㆍ6$H_2O$ would play an important role for the increase of sensor performance as a catalyst.nce as a catalyst.

• Journal of Biosystems Engineering
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• 제30권5호
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• pp.285-292
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• 2005

Extrusion process and physical properties of extrudates of pulp powder (TMP, thermomechanical pulp fibers) mixed with expanding additives was evaluated to develop biodegradable packaging materials. To find out the optimum condition, the status of extrusion process, coefficient of elastic and expansion ratio of extrudates were tested on the composites (wheat flour, soluble starch, polyvinyl alcohol), blending conditions of composites and moisture contents of extrudates. In case of material composition, wheat flour played a key role to keep extrusion process irrespective of the added amounts of soluble starch and polyvinyl alcohol. The coefficient of elastic of extrudates was increased and the expansion ratio was reduced as the added amounts of wheat flour increased. Also, the coefficient of elastic of extrudates was decreased as the moisture content of extrudates increased. The lowest coefficient of elastic was 439.55 kPa under the condition, of pulp powder mixed with $20\%$ of wheat flour based on pulp weight and $10\%$ of soluble starch based on wheat flour weight and controlled $20\%$(wb) of moisture content.

• Corrosion Science and Technology
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• 제18권6호
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• pp.243-252
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• 2019

The pitting corrosion and inhibition studies of AZ31B magnesium alloy were investigated in the alkaline solution (pH12) with chloride and inhibitors. The corrosion behavior of passive film with/without Cl^- in the alkaline electrolyte were conducted by polarization curve and immersion tests in the presence of various additives (inhibitors) to clarify the inhibition efficiency of pitting corrosion at higher potential region. Critical concentration of pitting corrosion for Mg alloy was evaluated with 0.005 M NaCl in 0.01 M NaOH on the anodic polarization behavior. Critical pitting of AZ31B Mg alloy in 0.01 M NaOH is a function of chlorides; E_pit = - 1.36 - 0.2 log [Cl^-]. When the Sodium Benzoate (SB) was only used as an inhibitor, a few metastable pits developed on the Mg surface by an immersion test despite no pitting corrosion on the polarization curve meaning that adsorption of SB on the surface is insufficient protection from pitting corrosion in the presence of chloride. The role of SB and Sodium Dodecylbenzenesulfonate (SDBS) inhibitors for the Mg alloy surface in the presence of chloride was suppressed from pitting corrosion to co-adsorb on the Mg alloy surface with strong formation of passive film preventing pitting corrosion.

• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.105-113
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• 2014

Performance tests on $Ni/Ce-ZrO_2/Al_2O_3$ catalysts with additives (MgO, $La_2O_3$) were investigated in the combined reforming processes (SCR, ATR, TRM) in order to produce hydrogen and carbon monoxide (it is called "syngas".). The catalyst characterization was conducted using the BET surface analyzer, X-ray diffraction (XRD), SEM, TPR and TGA. The combined reforming process was developed to adjust the syngas ratio depending on the synthetic fuel (methanol, DME and GTL) manufacturing processes. Ni-based catalysts supported on alumina has been generally recommended as a combined reforming reaction catalyst. It was found that both free NiO and complexed NiO species were responsible for the catalytic activity in the combined reforming of methane conversion, and the $Ce-ZrO_2$ binary support employed had improved the oxygen storage capacity and thermal stability. The additives, MgO and $La_2O_3$, also seemed to play an important role to prevent the formation of the carbon deposition over the catalysts. The experimental results were compared with the equilibrium data using a commercial simulation tool (PRO/II).

• 대한기계학회논문집B
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• 제29권9호
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• pp.979-987
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• 2005

Numerical simulations were performed at atmospheric pressure in order to understand the effect of additives on flame speed, flame temperature, radical concentrations, $NO_x$ formation, and heat flux in freely propagating $CH_4-Air$ flames. The additives were both carbon dioxide and hydrogen chloride which had a combination of physical and chemical behavior on hydrocarbon flame. In the flame established with the same mole of methane and additive, hydrogen chloride significantly contributed toward the reduction of flame speed, flame temperature, $NO_x$ formation and heat flux by the chemical effect, whereas carbon dioxide mainly did so by the physical effect. The impact of hydrogen chloride on the decrease of the radical concentration was about $1.4\~3.0$ times as large as that of carbon dioxide. Hydrogen chloride had higher effect on the reduction of $EI_{NO}$ than carbon dioxide because of the chemical effect of hydrogen chloride. The reaction, $OH+HCl{\rightarrow}Cl+H_2O$, played an important role in the heat flux from flames added by hydrogen chloride instead of the reaction, $OH+H_2{\rightarrow}H+H_2O$ which was an important reaction in hydrocarbon flames.