Academic literature on the topic 'Central composite rotatable design. eng'
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Journal articles on the topic "Central composite rotatable design. eng"
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Qin, Xu Da, Song Hua, Xiao Lai Ji, Shi Mao Chen, and Wang Yang Ni. "Surface Roughness Model for Helical Milling of Die-Steel Based on Response Surface Methodology." Key Engineering Materials 431-432 (March 2010): 346–50. http://dx.doi.org/10.4028/www.scientific.net/kem.431-432.346.
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Holes making process is widely applied in die steel machining, Helical milling a hole, also called orbital drill, is hole making process by milling in which the center of end mill orbits around the center of the hole while spinning on its axis and moving in the axial direction. The paper presents the secondary regression prediction model of the holes surface roughness for helical milling of die-steel. To minimize the number of experiments for the design parameters, response surface methodology (RSM) with orthogonal rotatable central composite design is used. By means of variance analyses and additional cutting experiments, the adequacy of this model is confirmed. The model will be helpful in selecting cutting conditions to meet surface finish requirements in helical milling operation.
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Sánchez-Sáenz, Carolina M., Vânia R. G. Nascimento, João D. Biagi, and Rafael A. de Oliveira. "Mathematical modeling of the drying of orange bagasse associating the convective method and infrared radiation." Revista Brasileira de Engenharia Agrícola e Ambiental 19, no. 12 (2015): 1178–84. http://dx.doi.org/10.1590/1807-1929/agriambi.v19n12p1178-1184.
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ABSTRACT Mathematical modeling enables dimensioning of dryers, optimization of drying conditions and the evaluation of process performance. The aim of this research was to describe the behavior of orange bagasse drying using Page's and Fick's second law models, and to assess activation energy (using Arrhenius equation), moisture content, water activity and bulk density of product at the end of the process. The drying experimental assays were performed in 2011 with convective air temperature between 36 and 64 ºC and infrared radiation application time in the range from 23 to 277 s in accordance with the experimental central composite rotatable design. Analysis of variance and F-test were applied to results. At the end of the drying process, moisture content was about 0.09 to 0.87 db and water activity was between 0.25 and 0.87. Bulk density did not vary under studied conditions. Empirical Page's model demonstrated better representation of experimental data than the Fick's model for spheres. Activation energy values were about 18.491; 14.975 and 11.421 kJ mol-1 for infrared application times of 60; 150 e 244 s, respectively.
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Dikshit, Mithilesh K., Asit B. Puri, and Atanu Maity. "Optimization of surface roughness in ball-end milling using teaching-learning-based optimization and response surface methodology." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, no. 14 (2016): 2596–607. http://dx.doi.org/10.1177/0954405416634266.
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Surface roughness is one of the most important requirements of the finished products in machining process. The determination of optimal cutting parameters is very important to minimize the surface roughness of a product. This article describes the development process of a surface roughness model in high-speed ball-end milling using response surface methodology based on design of experiment. Composite desirability function and teaching-learning-based optimization algorithm have been used for determining optimal cutting process parameters. The experiments have been planned and conducted using rotatable central composite design under dry condition. Mathematical model for surface roughness has been developed in terms of cutting speed, feed per tooth, axial depth of cut and radial depth of cut as the cutting process parameters. Analysis of variance has been performed for analysing the effect of cutting parameters on surface roughness. A second-order full quadratic model is used for mathematical modelling. The analysis of the results shows that the developed model is adequate enough and good to be accepted. Analysis of variance for the individual terms revealed that surface roughness is mostly affected by the cutting speed with a percentage contribution of 47.18% followed by axial depth of cut by 10.83%. The optimum values of cutting process parameters obtained through teaching-learning-based optimization are feed per tooth ( fz) = 0.06 mm, axial depth of cut ( Ap) = 0.74 mm, cutting speed ( Vc) = 145.8 m/min, and radial depth of cut ( Ae) = 0.38 mm. The optimum value of surface roughness at the optimum parametric setting is 1.11 µm and has been validated by confirmation experiments.
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Imtiaz, Abid, Adnan Tariq, Ajaz Bashir Janjua, Fahad Sarfraz, and Amar ul Hassan Khawaja. "Parametric Optimization of Butt Welded Polycarbonate using Response Surface Methodology." January 2021 40, no. 1 (2021): 38–52. http://dx.doi.org/10.22581/muet1982.2101.04.
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Friction Stir Welding (FSW) is a solid-state joining process for metals, non-metals and polymers. It is carried out with the help of a specially designed, non-consumable tool. The heat required, for creating a softened region at the faying surfaces, is generated by rotation of tool against the work piece material. Being a solid-state welding process, it offers several advantages like inducing minimum effect on the mechanical properties of base material, reduced shrinkage and distortion, no spatter or Ultra Violet (UV) radiations etc. However, developing a sound weld requires an appropriate combination of several process parameters e.g. the design of tool, its rotational and traversing speeds etc. To substantiate this aspect, an approach based on Response Surface Methodology (RSM) is presented during this paper that optimizes the combination of process parameters while investigating their effect on the mechanical properties of a friction stir welded butt joint configuration of Polycarbonate. To minimize the total number of combinations a Central Composite Rotatable Design (CCRD) is used with three factors and two levels. The results have shown that the butt joints fabricated at a traverse speed of 14 mm/min, rotational speed of 1700 RPM and with simple cylindrical conical tool geometry yielded the maximum ultimate tensile strength of 51.299 MPa.
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Alsalman, Fatemah B., and Hosahalli S. Ramaswamy. "Evaluation of Changes in Protein Quality of High-Pressure Treated Aqueous Aquafaba." Molecules 26, no. 1 (2021): 234. http://dx.doi.org/10.3390/molecules26010234.
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Chickpea cooking water (CCW), known as aquafaba, has potential as a replacement for egg whites due to its emulsion and foaming properties which come from the proteins and starch that leach out from chickpeas into the cooking water. High pressure (HP) processing has the ability to modify the functional characteristics of proteins. It is hypothesized that HP processing could favorably affect the functional properties of CCW proteins by influencing their structure. The objective of this study to evaluate the effect of HP treatment on the associated secondary structure, emulsion properties and thermal characteristics of CCW proteins. A central composite rotatable design is used with pressure level (227–573 MPa) and treatment time (6–24 min) as HP variables, and concentration of freeze dried CCW aquafaba powder (11–29%) as product variable, and compared to untreated CCW powder. HP improves aquafaba emulsion properties compared to control sample. HP reduces protein aggregates by 33.3%, while β-sheets decreases by 4.2–87.6% in which both correlated to increasing protein digestibility. α-helices drops by 50%. It affects the intensity of some HP treated samples, but not the trend of bands in most of them. HP treatment decreases Td and enthalpy because of increasing the degree of denaturation.
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T. S., Anilkumar, Yu-Jen Lu, and Jyh-Ping Chen. "Optimization of the Preparation of Magnetic Liposomes for the Combined Use of Magnetic Hyperthermia and Photothermia in Dual Magneto-Photothermal Cancer Therapy." International Journal of Molecular Sciences 21, no. 15 (2020): 5187. http://dx.doi.org/10.3390/ijms21155187.
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In this work, we aimed to develop liposomal nanocomposites containing citric-acid-coated iron oxide magnetic nanoparticles (CMNPs) for dual magneto-photothermal cancer therapy induced by alternating magnetic field (AMF) and near-infrared (NIR) lasers. Toward this end, CMNPs were encapsulated in cationic liposomes to form nano-sized magnetic liposomes (MLs) for simultaneous magnetic hyperthermia (MH) in the presence of AMF and photothermia (PT) induced by NIR laser exposure, which amplified the heating efficiency for dual-mode cancer cell killing and tumor therapy. Since the heating capability is directly related to the amount of entrapped CMNPs in MLs, while the liposome size is important to allow internalization by cancer cells, response surface methodology was utilized to optimize the preparation of MLs by simultaneously maximizing the encapsulation efficiency (EE) of CMNPs in MLs and minimizing the size of MLs. The experimental design was performed based on the central composite rotatable design. The accuracy of the model was verified from the validation experiments, providing a simple and effective method for fabricating the best MLs, with an EE of 87% and liposome size of 121 nm. The CMNPs and the optimized MLs were fully characterized from chemical and physical perspectives. In the presence of dual AMF and NIR laser treatment, a suspension of MLs demonstrated amplified heat generation from dual hyperthermia (MH)–photothermia (PT) in comparison with single MH or PT. In vitro cell culture experiments confirmed the efficient cellular uptake of the MLs from confocal laser scanning microscopy due to passive accumulation in human glioblastoma U87 cells originated from the cationic nature of MLs. The inducible thermal effects mediated by MLs after endocytosis also led to enhanced cytotoxicity and cumulative cell death of cancer cells in the presence of AMF–NIR lasers. This functional nanocomposite will be a potential candidate for bimodal MH–PT dual magneto-photothermal cancer therapy.
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Açıkalın, Korkut, Fatma Karaca, and Esen Bolat. "Central composite rotatable design for liquefaction of pine barks." Fuel Processing Technology 87, no. 1 (2005): 17–24. http://dx.doi.org/10.1016/j.fuproc.2005.04.005.
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V., Eyarkai Nambi, Gitanjali Behera, Vinod Kumar Saharan, and Vijay Singh Meena. "Optimization of salt curing of bitter gourd (Momordica charantia L.) with blanching as pre-treatment using response surface methodology." Nutrition & Food Science 46, no. 6 (2016): 742–52. http://dx.doi.org/10.1108/nfs-02-2016-0020.
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Purpose Pickling or salt curing is one of the major traditional processes to increase the shelf life of bitter gourd in India. No information is available about optimization of salt curing of bitter gourd and the related changes in its quality. Moreover, specific investigations are needed to evaluate individual susceptibility of fruit and vegetables to osmotic dewatering with pre-treatment to obtain new minimally processed food products. The purpose of this study is to optimize the salt curing process with blanching as pretreatment for bitter gourd. Design/methodology/approach A study was conducted to optimize the blanching and other process factors of salt curing (solution concentration and treatment time) based on mass transfer and quality factors of bitter gourd using response surface methodology. Experimental design was made using central composite rotatable design with different time of blanching, solution concentration and treatment time. The colour, firmness, water activity and other mass transfer kinetic parameters were used for optimization. Findings Blanching had significant effect (p < 0.001) on water loss (WL), weight reduction (WR), solid gain (SG), water activity and firmness of bitter gourd. Mass transfer kinetic parameters like WL, SG and normalized solid content increased and normalized moisture content was found to decrease with increase in solution concentration and curing time. Relationships between process variables and quality factors were established in either quadratic or linear form with higher R2 values. A 15 per cent solution concentration for the period of 5 h with the blanched samples at 800°C for 5.26 min was found to be the optimum condition for osmotic dehydration to achieve maximum WL and SG, minimum water activity and minimum changes in firmness. Practical implications The optimized combinations for the salt curing process would be more helpful for the processors and other stakeholders involved in the pickling process by reducing energy and other input resources. Social implications Mostly in India, the pickling process is carried out at micro- and small-scale level and in an unorganized way. This study would help those involved to reduce their input resources and to organize the process, thus leading to more dividends to the stakeholders and optimum price to the end-users. For the medium- and large-scale processing units, this study would give insight to automate the whole process in an efficient manner. Originality/value This study was performed using sophisticated and higher-end instruments. The data were observed meticulously and analysed with proper statistical tools, increasing the credibility of the study. This study gives concrete results which are directly useful to the stakeholders.
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Rybka, Ana Cecília Poloni, Sérgio Tonetto De Freitas, Acácio Figueiredo Netto, and Aline Camarão Telles Biasoto. "Central composite rotatable design approach to optimize ‘Italia’ raisin drying conditions." Comunicata Scientiae 6, no. 4 (2015): 454. http://dx.doi.org/10.14295/cs.v6i4.993.
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Considering its high demand and limited production, raisin represents an important alternative to diversify grape processed products around the world. The aim of this study was to determine the best combination between drying temperature and time required to reach the highest consumer acceptance of ‘Italia’ raisin produced in the semi-arid climate in Brazil. The drying conditions were combinations between drying temperatures of 50, 56, 70, 84 and 90°C and drying times of 16, 22, 35, 48 and 54 hours, following a central composite rotational design (CCRD). The best combination between drying temperature and time was estimated to be 70°C for 35 hours (h), based on overall consumer acceptance. According to the statistical analysis used, drying at 70 °C for 35h and at 59 °C for 28h results in equal overall consumer acceptance, being the second option the more economical. Taste and texture, raisin chroma values and pH were more positively correlated to overall acceptance. The results indicate that drying at 59ºC for 28 h is the most efficient drying condition for raisins from ‘Italia’ grapes grown in Brazilian semi-arid condition. This study uses a new approach based on the central composite rotatable design to determine the most efficient drying temperature and time for ‘Italia’ raisins.
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Coelho, R. S., A. Anschau, and R. Monte-Alegre. "Kojic acid production from glycerol: Optimization using central composite rotatable design." Journal of Biotechnology 150 (November 2010): 84. http://dx.doi.org/10.1016/j.jbiotec.2010.08.216.
Full textDissertations / Theses on the topic "Central composite rotatable design. eng"
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Gonçalves, Rafael Henrique. "Aplicação da metodologia de superfície de resposta na otimização da remediação de um solo arenoso contaminado com cobre /." Rio Claro : [s.n.], 2009. http://hdl.handle.net/11449/92744.
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Orientador: José Ricardo Sturaro<br>Banca: Paulo Milton Barbosa Landim<br>Banca: Adriana Cavalieri Sais<br>Resumo: A contaminação de solos por metais pesados constitui-se em um problema ambiental que, geralmente, produz riscos permanentes à saúde humana e aos sistemas ecológicos, portanto com freqüente necessidade de intervenção por meio de tecnologias de remediação. Uma de tecnologias alternativas para a remediação de solos contaminados com metais pesados é a lavagem de solos in situ, cujo processo de remoção de contaminantes do solo envolve a percolação de uma solução extratora. Este trabalho propõe o emprego da metodologia de superfície de resposta para ajustar um modelo que aponte combinações entre os parâmetros da solução extratora - concentração de etileno diaminotetraacético dissódico (Na2EDTA), volume e pH da solução extratora - que possibilitem reduzir a concentração de cobre de um solo arenoso, a níveis de risco inferiores aos valores de intervenção para os cenários de exposição adotados pela Companhia Ambiental do Estado de São Paulo. Para tanto, realizou-se uma série de ensaios de lixiviação em coluna utilizando-se um Neossolo Flúvico artificialmente contaminado (1257,3 mg kg-1). Os ensaios foram conduzidos em triplicata e configuraram um arranjo experimental do tipo planejamento composto central rotacional, composto por 15 diferentes combinações dos parâmetros da solução extratora e de uma replicata no ponto central. Os resultados obtidos mostraram que a metodologia de superfície de resposta possibilitou o ajuste de um modelo, que aponta combinações de concentração de Na2EDTA, volume e pH da solução extratora que permitem reduzir a concentração de cobre de um determinado Neossolo Flúvico a valores inferiores aos dispostos pela Companhia Ambiental do Estado de São Paulo, para os cenários de exposição industrial, residencial, agrícola ou de proteção máxima.<br>Abstract: The soil contamination by heavy metals is an environmental problem that usually produces permanent risk to human health and ecological systems that often need the intervention through remediation technologies. An alternative remediation technology for soils contaminated with heavy metals is the soil flushing, which the contaminant removing process involves the percolation of an extraction solution. This work proposes the use of response surface methodology to adjust a model that points out combinations among the parameters of the extraction solution -ethylenediaminetetraacetic disodium (Na2EDTA) concentration, volume e pH of extraction solution -to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by Environmental Company of Sao Paulo State. Thus, a series of tests in leaching column was carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup an experimental array of type central composite rotatable design, composed of 15 different combinations of the parameters of the extraction solution and one replicate in the center point. The results showed that the response surface methodology allowed the fit of a model that identifies combinations of Na2EDTA concentration, volume and pH of the extraction solution to reduce the concentration of copper in a Fluvisol to values lower than those adopted by Environmental Company of Sao Paulo State for the exposure scenarios, namely industrial, residential, agricultural or maximum protection.<br>Mestre
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Brandão, Kiany Sirley Ribeiro. "OTIMIZAÇÃO DO PROCESSO DE PRODUÇÃO DE BIODIESEL METÍLICO E ETÍLICO DO ÓLEO DE MAMONA (Ricinus Communis L.) APLICANDO UM DELINEAMENTO COMPOSTO CENTRAL ROTACIONAL (DCCR)." Universidade Federal do Maranhão, 2007. http://tedebc.ufma.br:8080/jspui/handle/tede/895.
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Previous issue date: 2007-08-29<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>The biodiesel is a biofuel obtained from renewable sources, as vegetable oils and
animal fats. The castor seeds (Ricinus communis L.) have a medium content of oil of
47%. This oil when transformed in biodiesel produces a fuel with a series of
environmental advantages in relation to petroleum diesel. Therefore in this work it
was made the optimization of the production process of the methyl and ethyl
biodiesel from castor oil, varying the reaction time, the catalyst amount and the
oil:alcohol ratio (methanol or ethanol) using a Central Rotatable Composite Design
(CRCD) symmetrical and of second order, constituted of two parts: the factorial 2n,
with central points, and the axial part. With base in this factorial planning, surfaces
and curves of responses and variance analysis, it was evaluated the effects and the
significance of the models for the responses variables, biodiesel yield in mass and
the esters content. For the production of methyl biodiesel, the greater biodiesel yield
in mass is reached when oil/methanol molar ratio 1:4-1:5; 0,4-1,2% of KOH and time
reaction 20-100 min, is used. In function of the esters content, the oil/methanol molar
ratio should be between 1:10 and 1:11,36, KOH concentration between 1,4 and 2,34
and reaction time between 120 and 140 min. The regression models of the methyl
biodiesel for ANOVA appropriately explained at the level of 95%, the data variation
(R2 = 0,90567, for yield biodiesel and R2 = 0,7654, for the esters content). For the
production of the ethyl biodiesel, the results of the factorial planning 23 showed that
the oil/ethanol ratio and the KOH concentration went statisticaly significant to the
biodiesel yield in mass and content of esters. The maximum yield can be reached
when oil/ethanol molar ratio between 1:10,4 and 1:12,35; 1,4 to 2% of KOH and 60-
100 min of reaction, is used. In function of the esters content, the oil/ethanol molar
ratio should be between 1:10,5 and 1:12,35, concentration of KOH between 1,4 and
2,0 % and time of reaction between 60 and 120 min. The regression models
explained the variation of the data appropriately (R2 = 0,71811, for biodiesel yield and
for esters content, R2 = 0,95217) and they acted significantly, to 95% of trust limit, the
relationship between the independent variables and the response. The samples of
the methyl and ethyl biodiesel of castor oil, in the optimized conditions, they are
inside of the limits preset by National Agency of the Petroleum, Natural Gas and
Biofuels.<br>O biodiesel é um biocombustível obtido a partir de fontes renováveis como óleos
vegetais e gorduras animais. As sementes de mamona (Ricinus communis L.)
possuem um teor médio de óleo de 47 %, que ao ser transformado em biodiesel
produz um combustível com uma série de vantagens ambientais em relação ao
diesel de petróleo. Portanto neste trabalho fez-se a otimização do processo de
produção do biodiesel metílico e etílico a partir de óleo de mamona, variando o
tempo de reação, a quantidade de catalisador e a relação de óleo:álcool (metanol ou
etanol) empregando um Delineamento Composto Central Rotacional (DCCR)
simétrico e de segunda ordem, constituído de duas partes: o fatorial 2n, com pontos
centrais, e a parte axial. Com base neste planejamento fatorial, superfícies e curvas
de respostas e análise de variância foram realizadas a avaliação dos efeitos e a
significância dos modelos para as variáveis de respostas, rendimento em massa do
biodiesel e o teor de ésteres. Para a produção de biodiesel metílico, o maior
rendimento em massa de biodiesel é alcançado quando se usa razão molar
óleo/metanol 1:4-1:5; 0,4-1,2 % de KOH e 20-100 min de reação. Em função do teor
de ésteres, a razão molar óleo:metanol deve estar entre 1:10 e 1:11,36,
concentração de KOH entre 1,4 e 2,34 e tempo de reação entre 120 e 140 min. Os
modelos de regressão do biodiesel metílico avaliados pela ANOVA explicaram
adequadamente ao nível de 95%, a variação dos dados (R2 = 0,90567, para
rendimento biodiesel e R2 = 0,7654, para o teor de ésteres). Para a produção do
biodiesel etílico, os resultados do planejamento fatorial 23 mostraram que a razão
óleo:etanol e a concentração de KOH foram estatisticamente significativos para o
rendimento em massa de biodiesel e teor de ésteres. O máximo rendimento pode
ser alcançado quando se usa razão molar óleo/etanol entre 1:10,4 e 1:12,35; 1,4 a
2 % de KOH e 60-100 min de reação. Em função do teor de ésteres, a razão molar
óleo:etanol deve estar entre 1:10,5 e 1:12,35, concentração de KOH entre 1,4 e
2,0 % e tempo de reação entre 60 e 120 min. Os modelos de regressão explicaram
adequadamente a variação dos dados (R2 = 0,71811, para rendimento biodiesel e
para o teor de ésteres, R2 = 0,95217) e representaram significativamente, a 95% de
limite de confiança, a relação entre as variáveis independentes e a resposta. As
amostras do biodiesel metílico e etílico de mamona, nas condições otimizadas,
encontram-se dentro dos limites preestabelecidos pela Agência Nacional do
Petróleo, Gás Natural e Biocombustíveis.
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Gonçalves, Rafael Henrique [UNESP]. "Aplicação da metodologia de superfície de resposta na otimização da remediação de um solo arenoso contaminado com cobre." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/92744.
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goncalves_rh_me_rcla.pdf: 965679 bytes, checksum: c05e92494197dce7544dd639d4fa9e8c (MD5)<br>Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)<br>A contaminação de solos por metais pesados constitui-se em um problema ambiental que, geralmente, produz riscos permanentes à saúde humana e aos sistemas ecológicos, portanto com freqüente necessidade de intervenção por meio de tecnologias de remediação. Uma de tecnologias alternativas para a remediação de solos contaminados com metais pesados é a lavagem de solos in situ, cujo processo de remoção de contaminantes do solo envolve a percolação de uma solução extratora. Este trabalho propõe o emprego da metodologia de superfície de resposta para ajustar um modelo que aponte combinações entre os parâmetros da solução extratora – concentração de etileno diaminotetraacético dissódico (Na2EDTA), volume e pH da solução extratora – que possibilitem reduzir a concentração de cobre de um solo arenoso, a níveis de risco inferiores aos valores de intervenção para os cenários de exposição adotados pela Companhia Ambiental do Estado de São Paulo. Para tanto, realizou-se uma série de ensaios de lixiviação em coluna utilizando-se um Neossolo Flúvico artificialmente contaminado (1257,3 mg kg-1). Os ensaios foram conduzidos em triplicata e configuraram um arranjo experimental do tipo planejamento composto central rotacional, composto por 15 diferentes combinações dos parâmetros da solução extratora e de uma replicata no ponto central. Os resultados obtidos mostraram que a metodologia de superfície de resposta possibilitou o ajuste de um modelo, que aponta combinações de concentração de Na2EDTA, volume e pH da solução extratora que permitem reduzir a concentração de cobre de um determinado Neossolo Flúvico a valores inferiores aos dispostos pela Companhia Ambiental do Estado de São Paulo, para os cenários de exposição industrial, residencial, agrícola ou de proteção máxima.<br>The soil contamination by heavy metals is an environmental problem that usually produces permanent risk to human health and ecological systems that often need the intervention through remediation technologies. An alternative remediation technology for soils contaminated with heavy metals is the soil flushing, which the contaminant removing process involves the percolation of an extraction solution. This work proposes the use of response surface methodology to adjust a model that points out combinations among the parameters of the extraction solution –ethylenediaminetetraacetic disodium (Na2EDTA) concentration, volume e pH of extraction solution –to reduce the concentration of copper in a sandy soil to risk levels lower than the intervention levels for exposure scenarios adopted by Environmental Company of Sao Paulo State. Thus, a series of tests in leaching column was carried out using a Fluvisol artificially contaminated (1257,3 mg kg-1). The tests were conducted in triplicate and setup an experimental array of type central composite rotatable design, composed of 15 different combinations of the parameters of the extraction solution and one replicate in the center point. The results showed that the response surface methodology allowed the fit of a model that identifies combinations of Na2EDTA concentration, volume and pH of the extraction solution to reduce the concentration of copper in a Fluvisol to values lower than those adopted by Environmental Company of Sao Paulo State for the exposure scenarios, namely industrial, residential, agricultural or maximum protection.
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Awadallak, Jamal Abd. "Uso de ultrassom na hidrólise enzimática do óleo de palma: síntese de diacilglicerol." Universidade Estadual do Oeste do Parana, 2012. http://tede.unioeste.br:8080/tede/handle/tede/1901.
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Previous issue date: 2012-02-15<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Diacylglycerol rich oils have its organoleptic characteristics very similar to those of conventional edible oils, but these oils do not tend to accumulate in the body, even when consumed in high quantities, making them a great resource in the fight against obesity. Palm oil ranks first the world production of edible oils mainly due to its low cost. This work aimed to propose a new technology for enzyme production using diacylglycerol lipase Lipozyme RM IM and ultrasound to promote water in oil emulsions, which increases the interfacial area of the system leading to higher reaction rates compared to conventional enzymatic processes. . The reactions were carried out at 55 °C with two different methods. First, the reaction system was exposed to ultrasonic waves for the whole reaction time, which led to enzymatic inactivation and water evaporation. Ultrasound was then used to promote emulsification of the water/oil system before the hydrolysis reaction, avoiding contact between the probe and the enzymes. Achieved conversions were superior to the conventional method further hydrolysis rate when the ultrasound is employed for emulsion formation was significantly greater. For 12 hours of reaction the conversion was 85% higher than the conventional method and 15% higher for a period of 24 hours of reaction. . An experimental design was used to optimize the ultrasound-related parameters and maximize the hydrolysis rate, and in these conditions, with a change in equilibrium, DAG production was evaluated.Better reaction conditions were achieved for the second method: 11.20 wt% (water+oil mass) water content, 1.36 wt% (water+oil mass) enzyme load, 12 h of reaction time, 1.2 min and 200 W of exposure to ultrasound. In these conditions diacylglycerol yield was 37.69 wt%.<br>Óleos enriquecidos com diacilglicerol possuem características organolépticas muito semelhantes às dos óleos comestíveis convencionais, porém, estes óleos não tendem a se acumular no organismo, mesmo quando consumidos em altas quantidades, tornando-os um grande recurso no combate à obesidade. O óleo de palma está no topo da produção mundial de óleos comestíveis principalmente devido ao seu baixo custo. Este trabalho teve como objetivo propor uma nova tecnologia para a produção enzimática de diacilglicerol empregando a lipase Lipozyme RM IM e utilizando ultrassom como gerador de emulsões de água em óleo, o que aumenta a área interfacial do sistema conduzindo a maiores taxas de reação em relação aos processos enzimáticos convencionais. A hidrólise parcial do óleo de palma foi realizada em meio livre de solventes a 55 °C em duas etapas distintas e comparadas com reações em condições semelhantes sem o uso do ultrassom. Primeiramente o sistema reacional foi exposto às ondas ultrassônicas, o que levou a taxas iniciais de reação elevadas, porém, as conversões obtidas foram baixas, em função da desativação enzimática e da evaporação de água, pelo longo período de exposição ao ultrassom. Posteriormente, utilizou-se o ultrassom para gerar emulsões antes a etapa reacional, não permitindo seu contato com o sistema contendo a enzima. As conversões obtidas foram superiores ao método convencional, além disso, taxa de hidrólise quando se empregou o ultrassom para a formação de emulsões foi significativamente maior. Para 12 horas de reação a conversão foi 85% superior ao método convencional e de 15% superior para um período de 24 horas de reação. Foi desenvolvido um planejamento fatorial, o delineamento central composto rotacional para avaliar os efeitos das variáveis tempo de exposição ao ultrassom, potência do ultrassom e razão água/óleo na conversão em ácidos graxos livres da reação, sendo que a razão água/óleo e o produto tempo x potência apresentaram os maiores efeitos. Nas melhores condições, foi produzido um óleo concentrado com 37,69% de DAG em de 12h de reação, exposto ao ultrassom por 1,2min à 200W.
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LI, MING-CHANG, and 李明昌. "A study on global precision rotatable central composite design and rotatable evolutionary operation." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/95933092954109707837.
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Hyder, Md Nasim. "Preparation, Characterization and Performance of Poly(vinyl alcohol) based Membranes for Pervaporation Dehydration of Alcohols." Thesis, 2008. http://hdl.handle.net/10012/4014.
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Pervaporation (PV), a non-porous membrane separation process, is gaining considerable attention for solvent separation in a variety of industries ranging from chemical to food and pharmaceutical to petrochemicals. The most successful application has been the dehydration of organic liquids, for which hydrophilic membranes are used. However, during pervaporation, excessive affinity of water towards hydrophilic membranes leads to undesirable swelling (water absorption) of the membrane matrix. To control swelling, often hydrophilic membranes are crosslinked to modify physicochemical (surface and bulk) properties. Since the transport of species in pervaporation is governed by sorption (affected by surface and bulk properties) and diffusion (affected by bulk properties), it is essential to study the effect of crosslinking on the surface and bulk physicochemical properties and their effects on separation performance.
This thesis focuses on the effect of crosslinking on the physicochemical properties (e.g., crystallinity, hydrophilicity, surface roughness) of hydrophilic polymeric membranes and their dehydration performance alcohol-water mixtures. Poly(vinyl alcohol), PVA was used as the base polymer to prepare membranes with various morphologies such as homogeneous, blended (with Chitosan, CS) and composite (with poly(sulfone), PSf) structures. Before applying the crosslinked membranes for the PV dehydration of alcohols, the physicochemical characterization were carried out using Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), tensile testing, contact angle and swelling experiments.
The crosslinked membranes showed an increase in surface hydrophobicity from the contact angle measurements as compared to the uncrosslinked membranes. AFM surface topography showed that the membrane surfaces have nodular structures and are rough at the nanometer scale and affected by the crosslinking conditions such as concentration and reaction time. Surface hydrophobicity and roughness was found to increase with increasing degree of crosslinking. DSC measurements showed an increase in melting temperature of the polymer membranes after crosslinking. For the PV dehydration of ethanol, a decrease in flux and an increase in selectivity were observed with increase in the degree of crosslinking.
Effects of membrane thickness (of PVA layer) for crosslinked PVA-PSf composite membranes were studied on PV dehydration of ethanol. Total flux and selectivity were statistically analyzed as a function of the membrane thickness. In general, the outcome agrees with the solution-diffusion (S-D) theory: the total flux was found to be significantly affected by the PVA layer thickness, while the selectivity remains nearly unaffected. Using the S-D theory, the mass transfer resistance of the selective layers was calculated and found to increase with thickness. The relatively small change observed for selectivity has been related to the crosslinking of the PVA layer that increases the surface hydrophobicity of the membrane.
Chitosan-Poly(vinyl alcohol), or CS-PVA, blended membranes were prepared by varying the blending ratio to control membrane crystallinity and its effect on the PV dehydration of ethylene glycol. The blended membranes were crosslinked interfacially with trimesoyl chloride (TMC)/hexane. The crystallinity of the membrane was found to decrease with increasing CS wt% in the blend. Although the crosslinked CS-PVA blend membranes showed improved mechanical strength, they became less flexible as detected in tensile testing. The resulting crosslinked CS-PVA blended membranes showed high flux and selectivity simultaneously, for 70-80wt% CS in the blend. The effect of feed flow-rate was studied to find the presence of concentration polarization for 90wt% EG in feed mixture as well. The crosslinked blend membrane with 75wt% CS showed a highest total flux of 0.46 kg/m2/h and highest selectivity of 663 when operating at 70oC with 90wt% EG in the feed mixture.
Effects of crosslinking concentration and reaction time of trimesoyl chloride (TMC) were studied on poly(vinyl alcohol)-poly(sulfone) or PVA-PSf composite membranes. Results showed a consistent trend of changes in the physicochemical properties: the degree of crosslinking, crystallinity, surface roughness, hydrophilicity and swelling degree all decrease with increasing crosslinking agent (TMC) concentration and reaction time. The crosslinked membrane performance was assessed with PV dehydration of ethylene glycol-water mixtures at a range of concentrations (30 to 90wt% EG). The total flux of permeation was found to decrease, while the selectivity to increase, with increasing TMC concentration and reaction time. The decrease in flux was most prominent at low EG concentrations in the feed mixtures.
A central composite rotatable design (CCRD) of response surface methodology was used to analyze PV dehydration performance of crosslinked poly(vinyl alcohol) (PVA) membranes. Regression models were developed for the flux and selectivity as a function of operating conditions such as, temperature, feed alcohol concentration, and flow-rate. Dehydration experiments were performed on two different alcohol-water systems: isopropanol-water (IPA-water) and ethanol-water (Et-water) mixtures around the azeotrope concentrations. Judged by the lack-of-fit criterion, the analysis of variance (ANOVA) showed the regression model to be adequate. The predicted flux and selectivity from the regression models were presented in 3-D surface plots over the whole ranges of operating variables. For both alcohol-water systems, quadratic effect of temperature and feed alcohol concentration showed significant (p < 0.0001) influence on the flux and selectivity. A strong interaction effect of temperature and concentration was observed on the selectivity for the Et-water system. For the dehydration of azeotropic IPA-water mixture (87.5wt% IPA), the optimized dehydration variables were found to be 50.5oC and 93.7 L/hr for temperature and flow-rate, respectively. On the other hand for azeotropic Et-water mixture (95.5wt% Et), the optimized temperature and flow-rate were found to be 57oC and 89.2 L/hr, respectively. Compared with experiments performed at optimized temperature and feed flow-rate, the predicted flux and selectivity of the azeotropic mixtures showed errors to be within 3-6 %.
Conference papers on the topic "Central composite rotatable design. eng"
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Agrawal, Shyam S., and Sanjay Agarwal. "Study of Tool Wear in EDM Using Statistical Design of Experiments." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67166.
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The tool wear, while machining a part in electric discharge machining (EDM) process, is of great concern in the researchers in recent years as the accuracy of tool wear directly affects the accuracy of the parts to be produced. The variation in tool wear may occur due to variation in the machining parameters such as current, spark gap, pulse duration, voltage, flushing of dielectric fluid, mode of flushing of dielectrics, taper angle of the tool, etc. This paper represents the effect of current, taper angle of tool and pulse duration on the tool wear during electrical discharge machining of EN-31 tool steel, as this is one of the materials being used increasingly in cold forming rolls, knurling tools, press tools, lathe centers, etc. The experiments have been conducted using “Central Composite Rotatable Design”. Results indicate that the tool wear could be reduced if machining is performed at low current values and low pulse duration and it could be further reduced with increase in the taper angle of tool.
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Das, Manas, V. K. Jain, and P. S. Ghoshdastidar. "Parametric Study of Process Parameters and Characterization of Surface Texture Using Rotational-Magnetorheological Abrasive Flow Finishing (R-MRAFF) Process." In ASME 2009 International Manufacturing Science and Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/msec2009-84320.
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In this paper an effort is made towards improving the performance of MRAFF process by providing a rotating magnetic field externally to the polishing medium by using permanent magnets in addition to the reciprocating motion provided to the polishing medium by a hydraulic unit. This finishing process creates a smooth mirror like finished surface with a few directional cutting marks (i.e. hatch pattern like honing) on the finished surface of stainless steel, brass, and EN-8 workpieces. Preliminary experimental study is conducted on MRAFF and rotational (R)-MRAFF processes to compare their process performance in terms of change in Ra (ΔRa) and change in material removal (ΔMR). Later complete experimental study of R-MRAFF process is carried out using central composite rotatable design (CCRD) and the responses are plotted using response surface methodology (RSM). Optimum finishing conditions are identified by optimization method developed by Derringer and Suich using Design-Expert® software. The present study shows that rotational speed of the magnet has significant effect on output response (%ΔRa). The finished surfaces are characterized in detail by atomic force micrographs (AFM), and scanning electron micrographs (SEM) to analyze the changes in surface generation at different RPM.
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Fadzilah, R. Hanum, B. Arianto Sobhana, and M. Mahfud. "Central composite rotatable design for investigation of microwave-assisted extraction of ginger (Zingiber officinale)." In INTERNATIONAL CONFERENCE OF CHEMICAL AND MATERIAL ENGINEERING (ICCME) 2015: Green Technology for Sustainable Chemical Products and Processes. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4938344.
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Pinto Ferreira Brasileiro, Pedro, Bruno Freitas, Darne Germano de Almeida, et al. "SURFACE TENSION STUDY FROM THE BIOSURFACTANT PRODUCED BY Candida guilliermondii UTILIZING A CENTRAL COMPOSITE ROTATABLE DESIGN." In Simpósio Nacional de Bioprocessos e Simpósio de Hidrólise Enzimática de Biomassa. Galoá, 2015. http://dx.doi.org/10.17648/sinaferm-2015-33717.
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Gheith, Ramla, Fethi Aloui, and Sassi Ben Nasrallah. "Optimization of a Stirling Engine Performances: A Study Based on Experiments Design Approach." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72239.
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The Stirling engine performances depend on several physicals characteristics and functioning parameters. The experimental design is an alternative to identify the parameters sets allowing optimal Stirling engine performances. So, a four factor Central Composite Rotatable Design (CCRD) was used to observe the effect of cooling water flowrate, initial charge pressure, heating temperature, and operation time on a Stirling engine brake power. The influence of each parameter and the effect of the interaction between two or three parameters on the engine performances are presented and analyzed. With modeling, optimal conditions for the Stirling engine functioning are the following: charge pressure of 8 bar, heating temperature of 500 °C and cooling water flow rates of 7.34 l/mn, independently of the engine operation time.
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Kurozawa, Louise Emy, Gabriel Alves de Oliveira Scafi, and Renan Alex Lazarin. "Influence of process conditions on quality of spouted bed dried okara." In 21st International Drying Symposium. Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7361.
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This study aimed to evaluate the spouted bed drying of okara with inert particles of polypropylene. A central composite rotatable design was carried out to verify the effect of drying air temperature and air flow on moisture content, techno-functional properties and trypsin inhibitors activity of dried product. Higher temperatures decreased emulsifying properties and trypsin inhibitor activity, probably due to thermal protein denaturation. In order to obtain a dried okara with maximum techno-functional properties and minimum moisture content and trypsin inhibitor activity, the optimal drying conditions were suggested: air temperature of 60ºC and air flow of 180 m3/h.Keywords: soy pulp; spouted bed drying; trypsin inhibitor activity; techno-functional properties; optimization
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Muralidharan, B., H. Chelladurai, and J. Ramkumar. "Experimental Investigation on Electro-Discharge Deposition Process." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62866.
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The demand for multifunctional micro parts is an ever increasing need for product miniaturization. Amongst the spectrum of micro manufacturing processes, Electro-Discharge Deposition (EDD) is a newly developing additive process to produce parts in micro scale. In EDD the tool and workpiece electrodes are connected to reverse polarity in order to remove material from anode which deposits on cathode surface. The advantage of EDD is, any conducting tool material can be deposited irrespective of its hardness on the specified conducting substrate. So far, limited work has been carried out to develop micro parts like micro cylinders, micro spiral structures, etc., by EDD. In this work an attempt has been made to study the effect of various process parameters like current, duty cycle, pulse on time, voltage and table feed rate in EDD using central composite rotatable design (CCRD). It is found from the experimental results that, current plays a significant role in deposition of tool material.
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Baraskar, S. S., and S. S. Banwait. "Application of Multiple Regression and Adaptive Neuro-Fuzzy Inference System for Prediction of Surface Roughness in EDM." In ASME 2012 International Manufacturing Science and Engineering Conference collocated with the 40th North American Manufacturing Research Conference and in participation with the International Conference on Tribology Materials and Processing. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/msec2012-7273.
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A manufacturing system is oriented towards higher production rate, better quality and reduced cost and time to make a product. Surface roughness is an index parameter for determining the quality of a machined product and is influenced by various input process parameters. Surface roughness prediction in Electrical Discharge Machine (EDM) is being attempted with many methodologies, yet there is a need to develop robust, autonomous and accurate predictive system. This work proposes the application of hybrid intelligent technique, multiple regression and adaptive neuro-fuzzy inference system (ANFIS) for prediction of surface roughness in EDM. An experimental data set is obtained with current, pulse-on time and pulse-off time as input parameters and surface roughness as output parameter. Central composite rotatable design was used to plan the experiments. Multiple regression model is developed using the experimental data, to generate additional input-output data set. The input-output data set is used for training and validation of the proposed technique. After validation, data are forwarded for prediction of surface roughness. The proposed hybrid model for the prediction of surface roughness has very good agreement with the experimental results.
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Sivapirakasam, S. P., R. Anand, G. R. Kannan, and K. R. Balasubramanian. "Optimization of Biodiesel Production Using RSM and Study of Combustion Characteristics on DI Diesel Engine." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86777.
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Biodiesel is a monoalkyl ester of fatty acid of long chain derived from vegetable oil or animal fats. In this present investigation deccan hemp oil, a non-edible vegetable oil is used as feed stock for the production of biodiesel. Response surface methodology based on Central Composite Rotatable Design (CCRD) is used to analyze the interaction effect and to optimize the transesterification reaction variables such as temperature, catalyst concentration and oil to methanol ratio on biodiesel yield. A quadratic model is developed based on the CCRD, correlating the yield of biodiesel with reaction variables. The predicted yield by optimization condition is found very close to the experimental values. The optimum condition for biodiesel production is found at the temperature of 55° C, oil to methanol ratio of 1:9, catalyst of 0.5%, stirring speed of 350 rpm and a reaction time of 3h gave the maximum yield of 95%. The physical and chemical properties of deccan hemp oil and its methyl ester is determined as per ASTM standards. The produced biodiesel showed shorter ignition delay of 10.5° CA and lower heat release rate when compared to diesel at full load condition.