• Advances in nano research
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• 제10권1호
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• pp.77-90
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• 2021

In the present study, novel chitosan coated magnetic magnetite (Fe3O4) nanoparticles were successfully biosynthesized from mushroom, Agaricus campestris, extract. The obtained bio-nanocomposite material was used to investigate ultra-fast and highly efficient for removal of Ni2+ ions in a fixed-bed column. Chitosan was treated as polyelectrolyte complex with Fe3O4 nanoparticles and a Fungal Bio-Nanocomposite Material (FBNM) was derived. The FBNM was characterized by using X-Ray Diffractometer (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Fourier Transform Infrared spectra (FTIR) and Thermogravimetric Analysis (TGA) techniques and under varied experimental conditions. The influence of some important operating conditions including pH, flow rate and initial Ni2+ concentration on the uptake of Ni2+ solution was also optimized using a synthetic water sample. A Central Composite Design (CCD) combined with Response Surface Modeling (RSM) was carried out to maximize Ni2+ removal using FBNM for adsorption process. A regression model was derived using CCD to predict the responses and analysis of variance (ANOVA) and lack of fit test was used to check model adequacy. It was observed that the quadratic model, which was controlled and proposed, was originated from experimental design data. The FBNM maximum adsorption capacity was determined as 59.8 mg g-1. Finally, developed method was applied to soft drinks to determine Ni2+ levels. Reusability of FBNM was tested, and the adsorption and desorption capacities were not affected after eight cycles. The paper suggests that the FBNM is a promising recyclable nanoadsorbent for the removal of Ni2+ from various soft drinks.

• 한국생산제조학회지
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• 제21권3호
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• pp.387-393
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• 2012

It is very difficult to determine suitable cutting conditions in order to obtain accurate cutting profiles because machining errors caused by tool deflection depend upon cutting conditions. In this study the relationship between real cutting profiles (inclined shapes and machining errors) and cutting conditions was modeled in order to fabricate draft angle on micro molds. CCD (Central Composite Design) of DOE (Design Of Experiment) and RSM (Response Surface Method) were applied in order to model the relationship between cutting conditions and machining errors. In order to use CCD the range of radial depth of cut was chosen by $10-90{\mu}m$ and the range of feedrate was chosen by 200-300mm/min, and 9 points of cutting conditions were chosen inside determined ranges. Then, actual cutting processes were carried out as respect to 9 points of cutting conditions, draft angles and real cutting profiles were measured on cutting profiles, each response surface function was determined by conducting response surface analysis and the functions were represented by 3-dimensional graphs, contour lines and $101{\times}101$ matrices. Consequently it is possible to determine suitable cutting conditions in order to obtain arbitrary given draft angles and cutting profiles by using modeling. To validate proposed approach in this study suitable cutting conditions were determined by modeling in order to obtain arbitrary given draft angle and cutting profile, and actual cutting processes were carried out. About 95% of good agreement between predicted and measured values was obtained.

• 한국식품영양과학회지
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• 제40권3호
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• pp.458-465
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• 2011

본 연구는 반응표면분석법(response surface methodology, RSM)을 적용하여 소맥 글루텐 산 가수분해물의 염 농도와 기질인 ribose와 소맥 글루텐 산 가수분해물의 농도가 MRP의 갈변도와 항산화 활성, 기호도에 미치는 영향을 분석하여 기질조건을 최적화 하고자 하였다. 종속변수 회귀식의 결정 계수($R^2$)는 각각 0.975, 0.960, 0.854로 나타났으며 반응모형에서 갈변도와 항산화 활성은 모두 ribose와 소맥 글루텐산 가수분해물의 농도가 증가함에 따라 증가하여 두 기질 농도에 영향을 크게 받았다. 그러나 갈변도는 소맥 글루텐산 가수분해물의 염 농도가 높아짐에 따라 감소하는 경향을 보였고 DPPH radical 소거활성은 염 농도의 영향을 받지 않았다. 관능적 기호도로 평가된 고기향미에 대한 향 특성은 소맥 글루텐의 염 농도가 낮으며 ribose의 농도에 비해 소맥글루텐 산 가수분해물의 농도가 높을 때 발현되었다. 본 실험에서 ribose와 소맥 글루텐 산 가수분해물을 이용한 MRP의 높은 DPPH radical 소거활성과 관능적으로 고기향미에 근접한 향 특성을 나타내는 최적조건으로서, 소맥 글루텐산 가수분해물의 염 농도가 3%, ribose 농도 6.2%와 소맥글루텐 산 가수분해물의 농도 13.27%로 나타났다. 이때 DPPH radical 소거활성은 700(DF)과 관능점수 8.42점을 만족시킬 수 있는 MRP를 얻을 수 있었다. 따라서 ribose와 소맥 글루텐 산 가수분해물로 제조된 MRP의 저염화에 따른 갈변도와 항산화 효과 및 관능적 기호도에 대하여 두 기질의 농도를 조절하여 최적화함으로써 이를 향상시킬 수 있을 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• 제38권3호
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• pp.191-198
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• 2010

본 연구는 과산화수소를 사용하여 팽나무에 발생된 변색을 제거하기 위하여 수행되었다. 최적표백조건(반응온도, 반응시간, 과산화수소 농도)을 구하기 위하여 반응표면분석법(Response Surface Method) 중의 하나인 $2^3$ 요인중심합성계획법에 따라 총 15가지 실험조건들이 선정되었다. 표백처리는 침지법에 의해서 수행되었으며 표백효과는 표백 전후의 명도차에 의해 평가되었다. 반응조건들이 명도차에 미치는 영향을 분석하여 반응표면 분석모델을 구축할 수 있었으며, 반응표면분석모델의 $R^2$ 값은 0.93으로 반응조건이 표백효과에 미치는 영향을 잘 반영하는 것으로 판단되었다. 표백에 가장 큰 영향을 미치는 인자는 과산화수소 농도였으며, 그 다음으로 반응시간과 반응온도의 순이었다. 과산화수소 농도가 3% 이상의 경우 표백효과가 다소 감소하며 $20^{\circ}C$에서는 원하는 표백효과를 획득할 수 없는 것으로 나타났다. 구축된 반응표면분석모델을 통하여 원하는 재색을 획득하 기 위하여 사용될 수 있는 여러 가지 반응조건의 조합이 제시될 수 있었다.

• 한국식품영양학회지
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• 제28권2호
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• pp.189-195
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• 2015

Failure of the functions involved in ingestion leads to, not only loss of enjoyment of eating, but also protein-energy malnutrition. Dysmasesis and difficulty of swallowing occurs in various diseases, but aging is a major cause. In the aging society, the proportion of elderly people with dysmasesis and difficulty of swallowing is expected to increase rapidly. Developing foods for the elderly that are easy to chew and swallow is thus required. This study was conducted to develop easily chewable and swallowable foods for the elderly who can crush foods and ingest with their own tongues, but occasionally have difficulty in drinking fluids such as water and tea. Various foods for the elderly with chewing and swallowing difficulties were used for sensory assessment. The sensory panel consisted of 10 dietitians (10 women) in nursing care facilities. The sensory optimal composite recipes were determined by central composite design (CCD). The sensory measurements were significantly different in saltiness (p<0.05), sweetness (p<0.05), and overall quality (p<0.05). The optimum formulation of stir fried anchovy calculated by numerical and graphical methods was 3.74 g of soy sauces and 30.17 g of oligo-saccharides. Stir fried anchovy had a moisture content, hardness and adhesiveness of 76.52%, 2.10, and -1.57, respectively.

• 한국식생활문화학회지
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• 제29권1호
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• pp.101-110
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• 2014

This study was performed to determine the optimal composition of a muffin added with jerusalem artichoke powder and oligosaccharide. The experiment was designed based on CCD (central composite design), and evaluation was carried out by means of RSM (response surface methodology), which included 10 experimental points with three replicates each for the two independent variables jerusalem artichoke powder and oligosaccharide. The experimental muffin was prepared according to a traditional recipe, except that the flour was partially replaced by jerusalem artichoke powder (5, 15, or 25%) and the sugar was partially replaced by oligosaccharide (25, 50, or 75%). Using F-test, height, moisture, a-value, b-value, springiness, cohesiveness, texture, and overall acceptability were expressed as a linear model, whereas volume, pH, L-value, appearance, flavor and taste were expressed as a quadratic model. Increased amounts of jerusalem artichoke powder led to reduction of sensory scores for appearance, flavor, taste, texture, and overall quality. The optimum formulation determined by the numerical and graphical methods were similar: jerusalem artichoke powder 10.99%, oligosaccharide 71.40%.

• Computers and Concrete
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• 제15권2호
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• pp.215-229
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• 2015

The emerging technology of self compacting concrete, fiber reinforcement together reduces vibration and substitute conventional reinforcement which help in improving the economic efficiency of the construction. The objective of this work is to find the regression model to determine the response surface of mix proportioning Steel Fiber Reinforced Self Compacting Concrete (SFSCC) using statistical investigation. A total of 30 mixtures were designed and analyzed based on Design of Experiment (DOE). The fresh properties of SCC and mechanical properties of concrete were studied using Response Surface Methodology (RSM). The results were analyzed by limited proportion of fly ash, fiber, volume combination ratio of two steel fibers with aspect ratio of 50/35: 60/30 and super plasticizer (SP) dosage. The center composite designs (CCD) have selected to produce the response in quadratic equation. The model responses included in the primary stage were flowing ability, filling ability, passing ability and segregation index whereas in harden stage of concrete, compressive strength, split tensile strength and flexural strength at 28 days were tested. In this paper, the regression model and the response surface plots have been discussed, and optimal results were found for all the responses.

• Structural Engineering and Mechanics
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• 제76권5호
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• pp.561-578
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• 2020

The present work addresses the surface integrity and chip morphology in finish hard turning of AISI D3 steel under nanofluid assisted minimum quantity lubrication (NFMQL) condition. The surface integrity aspects include microhardness, residual stress, white layer formation, machined surface morphology, and surface roughness. This experimental investigation aims to explore the feasibility of low-cost multilayer (TiCN/Al2O3/TiN) coated carbide tool in hard machining applications and to assess the propitious role of minimum quantity lubrication using graphene nanoparticles enriched eco-friendly radiator coolant based nano-cutting fluid for machinability improvement of hardened steel. Combined approach of central composite design (CCD) - analysis of variance (ANOVA), desirability function analysis, and response surface methodology (RSM) have been subsequently employed for experimental investigation, predictive modelling and optimization of surface roughness. With a motivational philosophy of "Go Green-Think Green-Act Green", the work also deals with economic analysis, and sustainability assessment under environmental-friendly NFMQL condition. Results showed that machining with nanofluid-MQL provided an effective cooling-lubrication strategy, safer and cleaner production, environmental friendliness and assisted to improve sustainability.

• 한국조리학회지
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• 제23권4호
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• pp.81-92
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• 2017

This research was studied to optimize the recipe of rice pound cake with two concentrations of Euonymus alatus and grape seed oil, using central composite design (CCD). The mixing condition of rice pound cake was optimized by subjecting it to sensory evaluation and mechanical and physicochemical analysis, using response surface methodology (RSM). The results of the mechanical and physicochemical analysis showed significant values for color (lightness, redness, yellowness), texture (hardness, springiness, chewiness, gumminess, cohesiveness), loss rate, volume, specific volume, sweetness, saltiness, moisture content and pH (p<0.05). The results of the sensory evaluation showed significant values for color, flavor, taste, softness, appearance and overall quality (p<0.05). As a result, the optimized compounding ratio was found to be 4.28 g of Euonymus alatus and 33.18 g of grape seed oil.

• Journal of the Korean Wood Science and Technology
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• 제45권2호
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• pp.182-194
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• 2017

The optimum alkali pretreatment parameters (reaction time, reaction temperature and potassium hydroxide concentration) for facilitate the conversion into fermentable sugar (glucose) from steam exploded (severity log Ro 2.45) barley husk were determined using Response Surface Methodology (RSM) based on a factorial Central Composite Design (CCD). The prediction of the response was carried out by a second-order polynomial model and regression analysis revealed that more than 88% of the variation can be explained by the models. The optimum conditions for maximum cellulose content were determined to be 201 min reaction time, $124^{\circ}C$ reaction temperature and 0.9% potassium hydroxide concentration. This data shows that the actual value obtained was similar to the predicted value calculated from the model. The pretreated barley husk using acid hydrolysis resulted in a glucose conversion of 94.6%. This research of steam explosion and alkali pretreatment was a promising method to improve cellulose-rich residue for lignocellulosic biomass.