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Sample records for surface methodology incorporates

  1. Response Surface Methodology

    NARCIS (Netherlands)

    Kleijnen, Jack P.C.

    2014-01-01

    Abstract: This chapter first summarizes Response Surface Methodology (RSM), which started with Box and Wilson’s article in 1951 on RSM for real, non-simulated systems. RSM is a stepwise heuristic that uses first-order polynomials to approximate the response surface locally. An estimated polynomial

  2. Incorporating Six Sigma Methodology Training into Chemical Engineering Education

    Science.gov (United States)

    Dai, Lenore L.

    2007-01-01

    Six Sigma is a buzz term in today's technology and business world and there has been increasing interest to initiate Six Sigma training in college education. We have successfully incorporated Six Sigma methodology training into a traditional chemical engineering course, Engineering Experimentation, at Texas Tech University. The students have…

  3. Generalized Response Surface Methodology : A New Metaheuristic

    NARCIS (Netherlands)

    Kleijnen, J.P.C.

    2006-01-01

    Generalized Response Surface Methodology (GRSM) is a novel general-purpose metaheuristic based on Box and Wilson.s Response Surface Methodology (RSM).Both GRSM and RSM estimate local gradients to search for the optimal solution.These gradients use local first-order polynomials.GRSM, however, uses

  4. Applications of response surface methodology approach to ...

    African Journals Online (AJOL)

    Applications of response surface methodology approach to determine the effect of temperature, time of incubation and light conditions on germination and germ tube growth of Puccinia coronata f.sp. avenae urediosopores.

  5. Radiological accidents: methodologies of radio nuclides dis incorporation

    International Nuclear Information System (INIS)

    Jimenez F, E. A.; Paredes G, L.; Cortes, A.

    2014-08-01

    Derived of the radioactive or nuclear material management, exists the risk that accidents can happen where people cases are presented with internal radioactive contamination, who will receive specialized medical care to accelerate the radioactive dis incorporation with the purpose of diminishing the absorbed dose and the associate biological effects. In this work treatments of radioactive dis incorporation were identified, in function of the radionuclide, radiation type, radioactive half life, biological half life, critical organ, ingestion duct and patient type. The factor time is decisive for the effectiveness of the selected treatment in the blockade stage (before the accident) or dis incorporation (after the accident); this factor is related with the radioactive and biological half lives. So to achieve dis incorporation efficiencies of more to 70%, the patient clinical treatment will begin before the first third of the biological half life of the radionuclide that generated the internal contamination. (Author)

  6. Physical parameter optimization by Response Surface Methodology ...

    African Journals Online (AJOL)

    Response Surface Methodology (RSM) is an empirical technique involving the use of Design Expert software to derive a predictive model similar to regression analysis. This present study explains the significant application of RSM in optimization of lipase production by Aspergillus niger. The experimental validation of the ...

  7. A methodology to incorporate organizational factors into human reliability analysis

    International Nuclear Information System (INIS)

    Li Pengcheng; Chen Guohua; Zhang Li; Xiao Dongsheng

    2010-01-01

    A new holistic methodology for Human Reliability Analysis (HRA) is proposed to model the effects of the organizational factors on the human reliability. Firstly, a conceptual framework is built, which is used to analyze the causal relationships between the organizational factors and human reliability. Then, the inference model for Human Reliability Analysis is built by combining the conceptual framework with Bayesian networks, which is used to execute the causal inference and diagnostic inference of human reliability. Finally, a case example is presented to demonstrate the specific application of the proposed methodology. The results show that the proposed methodology of combining the conceptual model with Bayesian Networks can not only easily model the causal relationship between organizational factors and human reliability, but in a given context, people can quantitatively measure the human operational reliability, and identify the most likely root causes or the prioritization of root causes caused human error. (authors)

  8. Incorporation of ICT in teaching methodologies of teaching specialization cecar to

    Directory of Open Access Journals (Sweden)

    Asdrúbal Antonio Atencia Andrade

    2013-12-01

    Full Text Available This project was to approach the incorporation of ICT in the teaching methodologies of Specialization in Teaching program of the University Corporation Caribbean city of Sincelejo, considering that the Information Technology and Communication. Objective: To characterize from a focus on basic ICT skills of teachers methodologies Specialization Program in Teaching. Methodology: The study was a historical hermeneutic and grounded theory was used in interventional symbolic Sampieri, Fernandez & Collado.

  9. Incorporation of advanced accident analysis methodology into safety analysis reports

    International Nuclear Information System (INIS)

    2003-05-01

    as structural analysis codes and computational fluid dynamics codes (CFD) are applied. The initial code development took place in the sixties and seventies and resulted in a set of quite conservative codes for the reactor dynamics, thermal-hydraulics and containment analysis. The most important limitations of these codes came from insufficient knowledge of the physical phenomena and of the limited computer memory and speed. Very significant advances have been made in the development of the code systems during the last twenty years in all of the above areas. If the data for the physical models of the code are sufficiently well established and allow quite a realistic analysis, these newer versions are called advanced codes. The assumptions used in the deterministic safety analysis vary from very pessimistic to realistic assumptions. In the accident analysis terminology, it is customary to call the pessimistic assumptions 'conservative' and the realistic assumptions 'best estimate'. The assumptions can refer to the selection of physical models, the introduction of these models into the code, and the initial and boundary conditions including the performance and failures of the equipment and human action. The advanced methodology in the present report means application of advanced codes (or best estimate codes), which sometimes represent a combination of various advanced codes for separate stages of the analysis, and in some cases in combination with experiments. The Safety Analysis Reports are required to be available before and during the operation of the plant in most countries. The contents, scope and stages of the SAR vary among the countries. The guide applied in the USA, i.e. the Regulatory Guide 1.70 is representative for the way in which the SARs are made in many countries. During the design phase, a preliminary safety analysis report (PSAR) is requested in many countries and the final safety analysis report (FSAR) is required for the operating licence. There is

  10. Nonlinear free vibration of piezoelectric nanobeams incorporating surface effects

    International Nuclear Information System (INIS)

    Hosseini-Hashemi, Shahrokh; Nahas, Iman; Fakher, Mahmood; Nazemnezhad, Reza

    2014-01-01

    In this study, the nonlinear free vibration of piezoelectric nanobeams incorporating surface effects (surface elasticity, surface tension, and surface density) is studied. The governing equation of the piezoelectric nanobeam is derived within the framework of Euler–Bernoulli beam theory with the von Kármán geometric nonlinearity. In order to satisfy the balance conditions between the nanobeam bulk and its surfaces, the component of the bulk stress, σ zz , is assumed to vary linearly through the nanobeam thickness. An exact solution is obtained for the natural frequencies of a simply supported piezoelectric nanobeam in terms of the Jacobi elliptic functions using the free vibration mode shape of the corresponding linear problem. Then, the influences of the surface effects and the piezoelectric field on the nonlinear free vibration of nanobeams made of aluminum and silicon with positive and negative surface elasticity, respectively, have been studied for various properties of the piezoelectric field, various nanobeam sizes and amplitude ratios. It is observed that if the Young’s modulus of a nanobeam is lower, the effect of the piezoelectric field on the frequency ratios (FRs) of the nanobeam will be greater. In addition, it is seen that by increasing the nanobeam length so that the nanobeam cross section is set to be constant, the surface effects and the piezoelectric field with negative voltage values increases the FRs, whereas it is the other way around when the nanobeam cross section is assumed to be dependent on the length of the nanobeam. (paper)

  11. Incorporation of europium III complex into nanoparticles and films obtained by the Sol-Gel methodology

    Directory of Open Access Journals (Sweden)

    Faley Jean de Sousa

    2010-03-01

    Full Text Available The sol-gel process is very effective for the preparation of new materials with potential applications in optics, sensors, catalyst supports, coatings, and specialty inorganic polymers that can be used as hosts for the accommodation of organic molecules. The low temperature employed in the process is the main advantage of this methodology. In this work, the europium (III complex with 1,10-phenantroline was prepared, and this luminescent complex was incorporated into silica nanoparticles and films by the sol-gel process. The nanoparticles were obtained by the modified Stöber methodology. The films were obtained by the dip-coating technique, at different deposition rates and numbers of layers. The nanoparticles and films were characterized by photoluminescence, thermal analysis, and Raman and infrared spectroscopies. Characterization revealed that the europium (III complex was not affected upon incorporation into the nanoparticles and films, opening a new field for the application of these materials.

  12. Surface design methodology - challenge the steel

    Science.gov (United States)

    Bergman, M.; Rosen, B.-G.; Eriksson, L.; Anderberg, C.

    2014-03-01

    The way a product or material is experienced by its user could be different depending on the scenario. It is also well known that different materials and surfaces are used for different purposes. When optimizing materials and surface roughness for a certain something with the intention to improve a product, it is important to obtain not only the physical requirements, but also the user experience and expectations. Laws and requirements of the materials and the surface function, but also the conservative way of thinking about materials and colours characterize the design of medical equipment. The purpose of this paper is to link the technical- and customer requirements of current materials and surface textures in medical environments. By focusing on parts of the theory of Kansei Engineering, improvements of the companys' products are possible. The idea is to find correlations between desired experience or "feeling" for a product, -customer requirements, functional requirements, and product geometrical properties -design parameters, to be implemented on new improved products. To be able to find new materials with the same (or better) technical requirements but a higher level of user stimulation, the current material (stainless steel) and its surface (brushed textures) was used as a reference. The usage of focus groups of experts at the manufacturer lead to a selection of twelve possible new materials for investigation in the project. In collaboration with the topical company for this project, three new materials that fulfil the requirements -easy to clean and anti-bacterial came to be in focus for further investigation in regard to a new design of a washer-disinfector for medical equipment using the Kansei based Clean ability approach CAA.

  13. Incorporation of ice sheet models into an Earth system model: Focus on methodology of coupling

    Science.gov (United States)

    Rybak, Oleg; Volodin, Evgeny; Morozova, Polina; Nevecherja, Artiom

    2018-03-01

    Elaboration of a modern Earth system model (ESM) requires incorporation of ice sheet dynamics. Coupling of an ice sheet model (ICM) to an AOGCM is complicated by essential differences in spatial and temporal scales of cryospheric, atmospheric and oceanic components. To overcome this difficulty, we apply two different approaches for the incorporation of ice sheets into an ESM. Coupling of the Antarctic ice sheet model (AISM) to the AOGCM is accomplished via using procedures of resampling, interpolation and assigning to the AISM grid points annually averaged meanings of air surface temperature and precipitation fields generated by the AOGCM. Surface melting, which takes place mainly on the margins of the Antarctic peninsula and on ice shelves fringing the continent, is currently ignored. AISM returns anomalies of surface topography back to the AOGCM. To couple the Greenland ice sheet model (GrISM) to the AOGCM, we use a simple buffer energy- and water-balance model (EWBM-G) to account for orographically-driven precipitation and other sub-grid AOGCM-generated quantities. The output of the EWBM-G consists of surface mass balance and air surface temperature to force the GrISM, and freshwater run-off to force thermohaline circulation in the oceanic block of the AOGCM. Because of a rather complex coupling procedure of GrIS compared to AIS, the paper mostly focuses on Greenland.

  14. Assessment of Wind Turbine Structural Integrity using Response Surface Methodology

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Svenningsen, Lasse; Moser, Wolfgang

    2016-01-01

    Highlights •A new approach to assessment of site specific wind turbine loads is proposed. •The approach can be applied in both fatigue and ultimate limit state. •Two different response surface methodologies have been investigated. •The model uncertainty introduced by the response surfaces is dete...

  15. Methodology of radionuclides dis incorporation in people related to nuclear and radiological accidents

    International Nuclear Information System (INIS)

    Jimenez F, E. A.

    2014-01-01

    In this paper a classification of the radiological and nuclear accidents is presented, describing which the activities are, where they have occurred, their incidence and the learned lessons in these successes. The radiological accidents in which radioactive materials intervene can occur anywhere, and they are related to no controlled dangerous sources (abandoned, lost, stolen, or found sources), improper use of dangerous industrial and medical sources, exposition and contamination of people in general by an unknown origin, serious over expositions, menaces and willful misconduct, emergencies during transportation of radioactive material. A person can receive a dose of radiation from an external source, because of radioactive material placed on skin or on equipment, or because of ingestion or inhalation of radiological particles. The ingestion or the inhalation of radioactive material can cause an internal dose to the whole body or to a specific organ during a period of time. That is why a description of the processes of incorporation, the stages of incorporation and a description of the biokinetic models are also realized to understand the ingestion, transference and the excretion of the radioactive elements. In order to offer help to a victim of internal contamination, the dosimetric and medical diagnosis is very important. The most important techniques of dosimetric diagnosis are the dosimetry in vivo (cytogenetics and the counting in vivo of the whole body) and the bioassays. These techniques allow obtain data such as the radionuclide, the target organ, the absorbed dose, etc. At the same time, the doctor in charge must be attentive to the patients symptoms and their manifestation time, since they are an indicator, first, the patient suffered an irradiation, and second, of the range esteem of the received radiation dose. These are the parameters that are useful as criterion to decide if a person has to receive some treatment and select the methodologies that

  16. Improvement of Safety Assessment Methodologies for Near Surface Disposal Facilities

    International Nuclear Information System (INIS)

    Batandjieva, B.; Torres-Vidal, C.

    2002-01-01

    The International Atomic Energy Agency (IAEA) Coordinated research program ''Improvement of Safety Assessment Methodologies for Near Surface Disposal Facilities'' (ISAM) has developed improved safety assessment methodology for near surface disposal facilities. The program has been underway for three years and has included around 75 active participants from 40 countries. It has also provided examples for application to three safety cases--vault, Radon type and borehole radioactive waste disposal facilities. The program has served as an excellent forum for exchange of information and good practices on safety assessment approaches and methodologies used worldwide. It also provided an opportunity for reaching broad consensus on the safety assessment methodologies to be applied to near surface low and intermediate level waste repositories. The methodology has found widespread acceptance and the need for its application on real waste disposal facilities has been clearly identified. The ISAM was finalized by the end of 2000, working material documents are available and an IAEA report will be published in 2002 summarizing the work performed during the three years of the program. The outcome of the ISAM program provides a sound basis for moving forward to a new IAEA program, which will focus on practical application of the safety assessment methodologies to different purposes, such as licensing radioactive waste repositories, development of design concepts, upgrading existing facilities, reassessment of operating repositories, etc. The new program will also provide an opportunity for development of guidance on application of the methodology that will be of assistance to both safety assessors and regulators

  17. Methodology for the Incorporation of Passive Component Aging Modeling into the RAVEN/ RELAP-7 Environment

    Energy Technology Data Exchange (ETDEWEB)

    Mandelli, Diego; Rabiti, Cristian; Cogliati, Joshua; Alfonsi, Andrea; Askin Guler; Tunc Aldemir

    2014-11-01

    Passive system, structure and components (SSCs) will degrade over their operation life and this degradation may cause to reduction in the safety margins of a nuclear power plant. In traditional probabilistic risk assessment (PRA) using the event-tree/fault-tree methodology, passive SSC failure rates are generally based on generic plant failure data and the true state of a specific plant is not reflected realistically. To address aging effects of passive SSCs in the traditional PRA methodology [1] does consider physics based models that account for the operating conditions in the plant, however, [1] does not include effects of surveillance/inspection. This paper represents an overall methodology for the incorporation of aging modeling of passive components into the RAVEN/RELAP-7 environment which provides a framework for performing dynamic PRA. Dynamic PRA allows consideration of both epistemic and aleatory uncertainties (including those associated with maintenance activities) in a consistent phenomenological and probabilistic framework and is often needed when there is complex process/hardware/software/firmware/ human interaction [2]. Dynamic PRA has gained attention recently due to difficulties in the traditional PRA modeling of aging effects of passive components using physics based models and also in the modeling of digital instrumentation and control systems. RAVEN (Reactor Analysis and Virtual control Environment) [3] is a software package under development at the Idaho National Laboratory (INL) as an online control logic driver and post-processing tool. It is coupled to the plant transient code RELAP-7 (Reactor Excursion and Leak Analysis Program) also currently under development at INL [3], as well as RELAP 5 [4]. The overall methodology aims to: • Address multiple aging mechanisms involving large number of components in a computational feasible manner where sequencing of events is conditioned on the physical conditions predicted in a simulation

  18. Design methodology to enhance high impedance surfaces performances

    Directory of Open Access Journals (Sweden)

    M. Grelier

    2014-04-01

    Full Text Available A methodology is introduced for designing wideband, compact and ultra-thin high impedance surfaces (HIS. A parametric study is carried out to examine the effect of the periodicity on the electromagnetic properties of an HIS. This approach allows designers to reach the best trade-off for HIS performances.

  19. Response Surface Methodology's Steepest Ascent and Step Size Revisited

    NARCIS (Netherlands)

    Kleijnen, J.P.C.; den Hertog, D.; Angun, M.E.

    2002-01-01

    Response Surface Methodology (RSM) searches for the input combination maximizing the output of a real system or its simulation.RSM is a heuristic that locally fits first-order polynomials, and estimates the corresponding steepest ascent (SA) paths.However, SA is scale-dependent; and its step size is

  20. Application of Response Surface Methodology for Optimizing Oil ...

    African Journals Online (AJOL)

    This study investigated the optimum processing conditions which give the maximum yield of oil extracted from tropical almond seed by the use of response surface methodology (RSM). The factors investigated were solvent concentration (50 – 100% v/v), extraction temperature (84 -100oC) and processing time (60 – 120 ...

  1. The utilization of the response surface methodology for the ...

    African Journals Online (AJOL)

    SERVER

    2007-12-03

    Dec 3, 2007 ... Drojdiile ca aliment-medicament. In: Anghel I (ed). Biologia si Tehnologia Drojdiilor, vol 2, Editura Tehnica, Bucharest. Shieh CJ, Liao HF, Lee CC (2003). Optimization of lipase-catalyzed biodiesel by response surface methodology, Bioresour. Technol. 88: 103-106. Smigelschi O, Woinarovschy A (1978).

  2. Application of response surface methodology optimization for the ...

    African Journals Online (AJOL)

    by HPLC-PAD-ESI-MS/MS, and used as raw material for producing CA which preparation process was optimized by response surface methodology (RSM). The research results indicated the main ingredients of CQAs in tobacco waste were identified as three isomers containing chlorogenic acid (5-caffecylquinic acid, ...

  3. The utilization of the response surface methodology for the ...

    African Journals Online (AJOL)

    A mutant strain of the yeast Saccharomyces cerevisiae growing on ethanol as single source of carbon and energy was used in optimization experiments at laboratory and micropilot scale, following the surface response methodology. The cultivation medium optimization was performed on the basis of maximization of dry cell ...

  4. Application of response surface methodology for determining cutting ...

    Indian Academy of Sciences (India)

    by software Minitab (multiple linear regression and response surface methodology) in order to express the influence degree of the main cutting variables such as cutting speed, feed rate and depth of cut on cutting force components. These models would be helpful in selecting cutting variables for optimization of hard cutting ...

  5. Incorporating Skew into RMS Surface Roughness Probability Distribution

    Science.gov (United States)

    Stahl, Mark T.; Stahl, H. Philip.

    2013-01-01

    The standard treatment of RMS surface roughness data is the application of a Gaussian probability distribution. This handling of surface roughness ignores the skew present in the surface and overestimates the most probable RMS of the surface, the mode. Using experimental data we confirm the Gaussian distribution overestimates the mode and application of an asymmetric distribution provides a better fit. Implementing the proposed asymmetric distribution into the optical manufacturing process would reduce the polishing time required to meet surface roughness specifications.

  6. Incorporating contact angles in the surface tension force with the ACES interface curvature scheme

    Science.gov (United States)

    Owkes, Mark

    2017-11-01

    In simulations of gas-liquid flows interacting with solid boundaries, the contact line dynamics effect the interface motion and flow field through the surface tension force. The surface tension force is directly proportional to the interface curvature and the problem of accurately imposing a contact angle must be incorporated into the interface curvature calculation. Many commonly used algorithms to compute interface curvatures (e.g., height function method) require extrapolating the interface, with defined contact angle, into the solid to allow for the calculation of a curvature near a wall. Extrapolating can be an ill-posed problem, especially in three-dimensions or when multiple contact lines are near each other. We have developed an accurate methodology to compute interface curvatures that allows for contact angles to be easily incorporated while avoiding extrapolation and the associated challenges. The method, known as Adjustable Curvature Evaluation Scale (ACES), leverages a least squares fit of a polynomial to points computed on the volume-of-fluid (VOF) representation of the gas-liquid interface. The method is tested by simulating canonical test cases and then applied to simulate the injection and motion of water droplets in a channel (relevant to PEM fuel cells).

  7. Solar radiation calculation methodology for building exterior surfaces

    Energy Technology Data Exchange (ETDEWEB)

    De la Flor, Francisco Jose Sanchez; Ortiz Cebolla, Rafael; Luis Molina Felix, Jose; Alvarez Dominguez, Servando [E S. Ingenieros. Grupo de Termotecnia, Avda. de los descubrimientos, s/n 41092 Sevilla (Spain)

    2005-11-01

    The present article shows a new methodology of calculation of the direct, diffuse and reflected incident solar radiation, in all type of surfaces, either in open urban environments or inside buildings. This methodology is applicable in problems related to solar access (space heating in buildings, shadowing of open spaces), solar gains (space cooling in buildings), and daylighting. Solar radiation is the most important contribution to the surface and volumetric energy balance during the daytime. Particularly, solar radiation is the main contributor to heat gains in buildings, especially in residential buildings, where internal gains are very low. Utilization of daylight in buildings may result in significant savings in electricity consumption for lighting while creating a higher quality indoor environment. Additional energy savings may also be realized during cooling season, when reduction of internal heat gains due to electric lighting results in a corresponding reduction of cooling energy consumption. The analysis of the existing calculation methods and proposed in the scientific bibliography for the calculation of the solar radiation in problems of solar access in winter, solar gains in summer, and daylighting, takes us to the necessity of outlining a new and complete methodology. This new methodology is applicable to all these problems with a great accuracy and calculation speed. (author)

  8. Incorporating a Constrained Optimization Algorithm into Remote- Sensing/Precision Agriculture Methodology

    Science.gov (United States)

    Morgenthaler, George; Khatib, Nader; Kim, Byoungsoo

    with information to improve their crop's vigor has been a major topic of interest. With world population growing exponentially, arable land being consumed by urbanization, and an unfavorable farm economy, the efficiency of farming must increase to meet future food requirements and to make farming a sustainable occupation for the farmer. "Precision Agriculture" refers to a farming methodology that applies nutrients and moisture only where and when they are needed in the field. The goal is to increase farm revenue by increasing crop yield and decreasing applications of costly chemical and water treatments. In addition, this methodology will decrease the environmental costs of farming, i.e., reduce air, soil, and water pollution. Sensing/Precision Agriculture has not grown as rapidly as early advocates envisioned. Technology for a successful Remote Sensing/Precision Agriculture system is now available. Commercial satellite systems can image (multi-spectral) the Earth with a resolution of approximately 2.5 m. Variable precision dispensing systems using GPS are available and affordable. Crop models that predict yield as a function of soil, chemical, and irrigation parameter levels have been formulated. Personal computers and internet access are in place in most farm homes and can provide a mechanism to periodically disseminate, e.g. bi-weekly, advice on what quantities of water and chemicals are needed in individual regions of the field. What is missing is a model that fuses the disparate sources of information on the current states of the crop and soil, and the remaining resource levels available with the decisions farmers are required to make. This must be a product that is easy for the farmer to understand and to implement. A "Constrained Optimization Feed-back Control Model" to fill this void will be presented. The objective function of the model will be used to maximize the farmer's profit by increasing yields while decreasing environmental costs and decreasing

  9. The Impact of Incorporating Antimicrobials into Implant Surfaces.

    Science.gov (United States)

    Hickok, N J; Shapiro, I M; Chen, A F

    2018-01-01

    With the increase in numbers of joint replacements, spinal surgeries, and dental implantations, there is an urgent need to combat implant-associated infection. In addition to stringent sterile techniques, an efficacious way to prevent this destructive complication is to create new implants with antimicrobial properties. Specifically, these implants must be active in the dental implant environment where the implant is bathed in the glycoprotein-rich salivary fluids that enhance bacterial adhesion, and propagation, and biofilm formation. However, in designing an antimicrobial surface, a balance must be struck between antimicrobial activity and the need for the implant to interact with the bone environment. Three types of surfaces have been designed to combat biofilm formation, while attempting to maintain osseous interactions: 1) structured surfaces where topography, usually at the nanoscale, decreases bacterial adhesion sufficiently to retard establishment of infection; 2) surfaces that actively elute antimicrobials to avert bacterial adhesion and promote killing; and 3) surfaces containing permanently bonded agents that generate antimicrobial surfaces that prevent long-term bacterial adhesion. Both topographical and elution surfaces exhibit varying, albeit limited, antimicrobial activity in vitro. With respect to covalent coupling, we present studies on the ability of the permanent antimicrobial surfaces to kill organisms while fostering osseointegration. All approaches have significant drawbacks with respect to stability and efficacy, but the permanent surfaces may have an edge in creating a long-term antibacterial environment.

  10. Development of a methodology for the safety assessment of near surface disposal facilities for radioactive waste

    International Nuclear Information System (INIS)

    Simon, I.; Cancio, D.; Alonso, L.F.; Agueero, A.; Lopez de la Higuera, J.; Gil, E.; Garcia, E.

    2000-01-01

    The Project on the Environmental Radiological Impact in CIEMAT is developing, for the Spanish regulatory body Consejo de Seguridad Nuclear (CSN), a methodology for the Safety Assessment of near surface disposal facilities. This method has been developed incorporating some elements developed through the participation in the IAEA's ISAM Programme (Improving Long Term Safety Assessment Methodologies for Near Surface Radioactive Waste Disposal Facilities). The first step of the approach is the consideration of the assessment context, including the purpose of the assessment, the end-Points, philosophy, disposal system, source term and temporal scales as well as the hypothesis about the critical group. Once the context has been established, and considering the peculiarities of the system, an specific list of features, events and processes (FEPs) is produced. These will be incorporated into the assessment scenarios. The set of scenarios will be represented in the conceptual and mathematical models. By the use of mathematical codes, calculations are performed to obtain results (i.e. in terms of doses) to be analysed and compared against the criteria. The methodology is being tested by the application to an hypothetical engineered disposal system based on an exercise within the ISAM Programme, and will finally be applied to the Spanish case. (author)

  11. Enhancing nitrilase production from Fusarium proliferatum using response surface methodology.

    Science.gov (United States)

    Yusuf, Farnaz; Chaubey, Asha; Raina, Arvind; Jamwal, Urmila; Parshad, Rajinder

    2013-12-01

    The individual and interactive effects of three independent variables i.e. carbon source (glucose), nitrogen source (sodium nitrate) and inducer (ϵ-caprolactam) on nitrilase production from Fusarium proliferatum were investigated using design of experiments (DOE) methodology. Response surface methodology (RSM) was followed to generate the process model and to obtain the optimal conditions for maximum nitrilase production. Based on central composite design (CCD) a quadratic model was found to fit the experimental data (pnitrilase activity of 58.3U/g biomass obtained experimentally correlated to the predicted activity which proves the authenticity of the model. Overall 2.24 fold increase in nitrilase activity was achieved as compared to the activity before optimization (26U/g biomass).

  12. Incorporating a constrained optimization algorithm into remote sensing/precision agriculture methodology

    Science.gov (United States)

    Moreenthaler, George W.; Khatib, Nader; Kim, Byoungsoo

    2003-08-01

    For two decades now, the use of Remote Sensing/Precision Agriculture to improve farm yields while reducing the use of polluting chemicals and the limited water supply has been a major goal. With world population growing exponentially, arable land being consumed by urbanization, and an unfavorable farm economy, farm efficiency must increase to meet future food requirements and to make farming a sustainable, profitable occupation. "Precision Agriculture" refers to a farming methodology that applies nutrients and moisture only where and when they are needed in the field. The real goal is to increase farm profitability by identifying the additional treatments of chemicals and water that increase revenues more than they increase costs and do no exceed pollution standards (constrained optimization). Even though the economic and environmental benefits appear to be great, Remote Sensing/Precision Agriculture has not grown as rapidly as early advocates envisioned. Technology for a successful Remote Sensing/Precision Agriculture system is now in place, but other needed factors have been missing. Commercial satellite systems can now image the Earth (multi-spectrally) with a resolution as fine as 2.5 m. Precision variable dispensing systems using GPS are now available and affordable. Crop models that predict yield as a function of soil, chemical, and irrigation parameter levels have been developed. Personal computers and internet access are now in place in most farm homes and can provide a mechanism for periodically disseminating advice on what quantities of water and chemicals are needed in specific regions of each field. Several processes have been selected that fuse the disparate sources of information on the current and historic states of the crop and soil, and the remaining resource levels available, with the critical decisions that farmers are required to make. These are done in a way that is easy for the farmer to understand and profitable to implement. A "Constrained

  13. PREDICTION OF SURFACE ROUGHNESS IN END MILLING OPERATION OF DUPLEX STAINLESS STEEL USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    S. D. PHILIP

    2015-03-01

    Full Text Available Response surface methodology has been used to study the effects of the machining parameters such as spindle speed, feed rate and axial depth of cut on surface roughness of duplex stainless steel in end milling operation. Dry milling experiments were conducted with three levels of spindle speed, feed rate and axial depth of cut. A mathematical model has been developed to predict the surface roughness in terms of the machining parameters using Box-Behnken design response surface methodology. The adequacy of the model was verified using analysis of variance. The prediction equation shows that the feed rate is the most important factor that influences the surface roughness followed by axial depth of cut and spindle speed. The validity of the model was verified by conducting the confirmation experiment.

  14. Radiological accidents: methodologies of radio nuclides dis incorporation; Accidentes radiologicos: metodologias de desincorporacion de radionuclidos

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez F, E. A. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Cortes, A., E-mail: lydia.paredes@inin.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2014-08-15

    Derived of the radioactive or nuclear material management, exists the risk that accidents can happen where people cases are presented with internal radioactive contamination, who will receive specialized medical care to accelerate the radioactive dis incorporation with the purpose of diminishing the absorbed dose and the associate biological effects. In this work treatments of radioactive dis incorporation were identified, in function of the radionuclide, radiation type, radioactive half life, biological half life, critical organ, ingestion duct and patient type. The factor time is decisive for the effectiveness of the selected treatment in the blockade stage (before the accident) or dis incorporation (after the accident); this factor is related with the radioactive and biological half lives. So to achieve dis incorporation efficiencies of more to 70%, the patient clinical treatment will begin before the first third of the biological half life of the radionuclide that generated the internal contamination. (Author)

  15. OPTIMIZATION OF TANNASE POSITIVE PROBIOTIC PRODUCTION BY SURFACE RESPONSE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Yumnam S.

    2014-10-01

    Full Text Available Study in conditions in vitro of eight Lactobacillus strains procured from culture repositories for their probiotic potential and extracellular tannase activity was the aim of the research. Based upon acid, bile salt tolerance and antibiotic resistance L. plantarum MTCC 2621 with high tannase activity was selected for production studies. Optimization of nutrient medium in 3 L bioreactor was optimized by Surface Response Methodology based on the Full Factorial Central Composite Design. A factorial design 23 augmented by 6 axial points (α = 1.68 and six replicates at the center point was implemented in 20 experiments. The optimized conditions were found to be pH 5.69, contain of lactose 128.58 g/l, peptone 8 g/l. A tenfold increase in the biomass production was observed using the optimized nutrient medium in bioreactor as compared to initial MRS medium.

  16. Application of response surface methodology method in designing corrosion inhibitor

    Science.gov (United States)

    Asmara, Y. P.; Athirah; Siregar, J. P.; Kurniawan, T.; Bachtiar, D.

    2017-10-01

    In oil and gas pipelines and offshore structure, inhibitors have been considered to be the first choice to reduce corrosion rate. There are many corrosion inhibitor compositions available in the market. To produce the best corrosion inhibitor requires many experimental data which is not efficient. These experiments used response surface methodology (RSM) to select corrosion inhibitor compositions. The experiments investigated effects of corrosion inhibition on corrosion rate of low carbon steel in 3% NaCl solution with different concentrations of selected main inhibitor compositions which are ethyl acetate (EA), ethylene glycol (EG) and sodium benzoate (SB). Corrosion rate were calculated using linear polarization resistance (LPR). All of the experiments were set in natural conditions at pH 7. MINITAB® version 15 was used for data analysis. It is shown that a quadratic model is a representative model can predict best corrosion inhibitor composition comprehensibly.

  17. Maximization of fructose esters synthesis by response surface methodology.

    Science.gov (United States)

    Neta, Nair Sampaio; Peres, António M; Teixeira, José A; Rodrigues, Ligia R

    2011-07-01

    Enzymatic synthesis of fructose fatty acid ester was performed in organic solvent media, using a purified lipase from Candida antartica B immobilized in acrylic resin. Response surface methodology with a central composite rotatable design based on five levels was implemented to optimize three experimental operating conditions (temperature, agitation and reaction time). A statistical significant cubic model was established. Temperature and reaction time were found to be the most significant parameters. The optimum operational conditions for maximizing the synthesis of fructose esters were 57.1°C, 100 rpm and 37.8 h. The model was validated in the identified optimal conditions to check its adequacy and accuracy, and an experimental esterification percentage of 88.4% (±0.3%) was obtained. These results showed that an improvement of the enzymatic synthesis of fructose esters was obtained under the optimized conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Aerodynamic configuration design using response surface methodology analysis

    Science.gov (United States)

    Engelund, Walter C.; Stanley, Douglas O.; Lepsch, Roger A.; Mcmillin, Mark M.; Unal, Resit

    1993-01-01

    An investigation has been conducted to determine a set of optimal design parameters for a single-stage-to-orbit reentry vehicle. Several configuration geometry parameters which had a large impact on the entry vehicle flying characteristics were selected as design variables: the fuselage fineness ratio, the nose to body length ratio, the nose camber value, the wing planform area scale factor, and the wing location. The optimal geometry parameter values were chosen using a response surface methodology (RSM) technique which allowed for a minimum dry weight configuration design that met a set of aerodynamic performance constraints on the landing speed, and on the subsonic, supersonic, and hypersonic trim and stability levels. The RSM technique utilized, specifically the central composite design method, is presented, along with the general vehicle conceptual design process. Results are presented for an optimized configuration along with several design trade cases.

  19. Heterogeneous Effects in Education: The Promise and Challenge of Incorporating Intersectionality into Quantitative Methodological Approaches

    Science.gov (United States)

    Schudde, Lauren

    2018-01-01

    To date, the theory of intersectionality has largely guided qualitative efforts in social science and education research. Translating the construct to new methodological approaches is inherently complex and challenging, but offers the possibility of breaking down silos that keep education researchers with similar interests--but different…

  20. Methodology for evaluating the insect growth regulator (IGR) methoprene incorporated into packaging films

    Science.gov (United States)

    The insect growth regulator methoprene has been impregnated onto various packaging materials to control stored product insects, and is labeled for use in this manner in the United States. Different methodologies were utilized to evaluate efficacy towards Tribolium castaneum (Herbst), the red flour b...

  1. Optimization of sustained release aceclofenac microspheres using response surface methodology

    International Nuclear Information System (INIS)

    Deshmukh, Rameshwar K.; Naik, Jitendra B.

    2015-01-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14 ± 0.015% to 85.34 ± 0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12 h. The optimized microspheres formulation showed E.E. of 84.87 ± 0.005 with small error value (1.39). The low magnitudes of error and the significant value of R 2 in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects. - Highlights: • Aceclofenac microspheres were

  2. Optimization of sustained release aceclofenac microspheres using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, Rameshwar K.; Naik, Jitendra B., E-mail: jitunaik@gmail.com

    2015-03-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14 ± 0.015% to 85.34 ± 0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12 h. The optimized microspheres formulation showed E.E. of 84.87 ± 0.005 with small error value (1.39). The low magnitudes of error and the significant value of R{sup 2} in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects. - Highlights: • Aceclofenac microspheres

  3. Lactoperoxidase catalyzed radioiodination of cell surface immunoglobulin: incorporated radioactivity may not reflect relative cell surface Ig density

    International Nuclear Information System (INIS)

    Wilder, R.L.; Yuen, C.C.; Mage, R.G.

    1979-01-01

    Rabbit and mouse splenic lymphocytes were radioiodinated by the lactoperoxidase technique, extracted with non-ionic detergent, immunoprecipitated with high titered rabbit anti-kappa antisera, and compared by SDS-PAGE. Mouse sIg peaks were reproducibly larger in size than rabbit sIg peaks (often greater than 10 times). Neither differences in incorporation of label into the rabbit cell surface, nor differences in average sIg density explain this result. Total TCA-precipitable radioactivity was similar in each species. Estimation of the relative amounts of sIg in the mouse and rabbit showed similar average sIg densities. Differences in detergent solubility, proteolytic lability, or antisera used also do not adequately account for this difference. Thus, these data indicate that radioactivity incorporated after lactoperoxidase catalyzed cell surface radioiodination may not reflect cell surface Ig density. Conclusions about cell surface density based upon relative incorporation of radioactivity should be confirmed by other approaches

  4. Synthesis of structured triacylglycerols containing caproic acid by lipase-catalyzed acidolysis: Optimization by response surface methodology

    DEFF Research Database (Denmark)

    Zhou, D.Q.; Xu, Xuebing; Mu, Huiling

    2001-01-01

    Production in a batch reactor with a solvent-free system of structured triacylglycerols containing short-chain fatty acids by Lipozyme RM IM-catalyzed acidolysis between rapeseed oil and caproic acid was optimized using response surface methodology (RSM). Reaction time (t(r)), substrate ratio (S......-r = 2-6 mol/mol; and W-c = 2-12 wt %. The biocatalyst was Lipozyme RM IM, in which Rhizomucor miehei lipase is immobilized on a resin. The incorporation of caproic acid into rapeseed oil was the main monitoring response. In addition, the contents of mono-incorporated structured triacylglycerols and di...

  5. [Theoretical, conceptual and methodological incorporation of the educator Paulo Freire in research].

    Science.gov (United States)

    Heidemann, Ivonete Buss Schülter; Boehs, Astrid Eggert; Wosny, Antônio Miranda; Stulp, Karine Patrícia

    2010-01-01

    This study aims to present the application of the Method of Paulo Freire in a research with professionals of family health teams, users and community leaders about the use of the notion of health promotion. It describes how to obtain and analyze data in the Culture Circles performed in three phases: thematic research, coding /decoding and unveiling critical. This methodology contributed reflections of health practices of participants, allowing alternatives to transform them. The theoretical limits for their payment, among them the difficulty of deconstruction of the authoritarian conferred by the power of professional knowledge.

  6. A proper methodology aimed at surface wave tomography

    Directory of Open Access Journals (Sweden)

    J. Badal

    1997-06-01

    Full Text Available When applying a methodology for obtaining the 3D shear-wave velocity structure of a medium from surface wave dispersion data, the problem must be considered with caution since one inverts path-averaged velocities and the use of any inversion method entails some drawbacks such as lack of uniqueness, unwarranted stability and constraints affecting the data. In order to avoid the application of consecutive inversions and to overcome these drawbacks, we propose alternative mapping methods, for example spatial prediction methods, or else the use of an algorithm that, from a mathematical viewpoint, can be understood through the application of the orthogonal projection theorem onto convex sets (POCS. Among the first ones, we try inverse weighted distance interpolation. The POCS algorithm we have used discretises a second order differential equation for the velocity field with boundary conditions. All these imaging techniques aimed at volumetric modelling and the visualisation of data are discussed, and finally we show some results based on ray path velocities obtained previously by inversion of phase and group velocities of Rayleigh waves propagating across the Iberian peninsula.

  7. Computational optimization of biodiesel combustion using response surface methodology

    Directory of Open Access Journals (Sweden)

    Ganji Prabhakara Rao

    2017-01-01

    Full Text Available The present work focuses on optimization of biodiesel combustion phenomena through parametric approach using response surface methodology. Physical properties of biodiesel play a vital role for accurate simulations of the fuel spray, atomization, combustion, and emission formation processes. Typically methyl based biodiesel consists of five main types of esters: methyl palmitate, methyl oleate, methyl stearate, methyl linoleate, and methyl linolenate in its composition. Based on the amount of methyl esters present the properties of pongamia bio-diesel and its blends were estimated. CONVERGETM computational fluid dynamics software was used to simulate the fuel spray, turbulence and combustion phenomena. The simulation responses such as indicated specific fuel consumption, NOx, and soot were analyzed using design of experiments. Regression equations were developed for each of these responses. The optimum parameters were found out to be compression ratio – 16.75, start of injection – 21.9° before top dead center, and exhaust gas re-circulation – 10.94%. Results have been compared with baseline case.

  8. Response surface methodology of nitrilase production by recombinant Escherichia coli.

    Science.gov (United States)

    Dubey, Sachin; Singh, Amit; Banerjee, Uttam C

    2011-07-01

    Growth and nitrilase production by recombinant Escherichia coli cells harbouring pET 21 (b) plasmid, for the expression of Pseudomonas putida nitrilase were improved using response surface methodology. Central composite design was used for obtaining ideal concentration of critical medium components which include fructose, tryptone, yeast extract and lactose. The optimal values for the concentration of fructose, tryptone, yeast extract and lactose were found to be 1.13, 2.26, 3.25 and 0.9 % (w/v), respectively. Here, fructose served as carbon source for the growth while lactose was preferably used as inducer for the expression of foreign protein. Yeast extract in the medium was used as a growth promoter while tryptone was added as a major nitrogen source. Using this optimized medium, an experimental growth of 6.67 (OD at 600 nm) and nitrilase activity of 27.13 U/ml was achieved. This approach for medium development led to an enhancement of the growth and enzyme activity by 1.4 and 2.2 times, respectively, as compared to the un-optimized medium.

  9. Response surface methodology of nitrilase production by recombinant Escherichia coli

    Directory of Open Access Journals (Sweden)

    Sachin Dubey

    2011-09-01

    Full Text Available Growth and nitrilase production by recombinant Escherichia coli cells harbouring pET 21 (b plasmid, for the expression of Pseudomonas putida nitrilase were improved using response surface methodology. Central composite design was used for obtaining ideal concentration of critical medium components which include fructose, tryptone, yeast extract and lactose. The optimal values for the concentration of fructose, tryptone, yeast extract and lactose were found to be 1.13, 2.26, 3.25 and 0.9 % (w/v, respectively. Here, fructose served as carbon source for the growth while lactose was preferably used as inducer for the expression of foreign protein. Yeast extract in the medium was used as a growth promoter while tryptone was added as a major nitrogen source. Using this optimized medium, an experimental growth of 6.67 (OD at 600 nm and nitrilase activity of 27.13 U/ml was achieved. This approach for medium development led to an enhancement of the growth and enzyme activity by 1.4 and 2.2 times, respectively, as compared to the un-optimized medium.

  10. Optimization of vibratory welding process parameters using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pravin Kumar; Kumar, S. Deepak; Patel, D.; Prasad, S. B. [National Institute of Technology Jamshedpur, Jharkhand (India)

    2017-05-15

    The current investigation was carried out to study the effect of vibratory welding technique on mechanical properties of 6 mm thick butt welded mild steel plates. A new concept of vibratory welding technique has been designed and developed which is capable to transfer vibrations, having resonance frequency of 300 Hz, into the molten weld pool before it solidifies during the Shielded metal arc welding (SMAW) process. The important process parameters of vibratory welding technique namely welding current, welding speed and frequency of the vibrations induced in molten weld pool were optimized using Taguchi’s analysis and Response surface methodology (RSM). The effect of process parameters on tensile strength and hardness were evaluated using optimization techniques. Applying RSM, the effect of vibratory welding parameters on tensile strength and hardness were obtained through two separate regression equations. Results showed that, the most influencing factor for the desired tensile strength and hardness is frequency at its resonance value, i.e. 300 Hz. The micro-hardness and microstructures of the vibratory welded joints were studied in detail and compared with those of conventional SMAW joints. Comparatively, uniform and fine grain structure has been found in vibratory welded joints.

  11. Assessment of methodology for 131I determination in workers exposed to incorporation

    International Nuclear Information System (INIS)

    Cerchetti, Maria L.; Arguelles, Maria G.

    2005-01-01

    In this work a technique used to monitor internal contamination of workers exposed to Iodine-131 incorporation from Radioisotope Production Plant was assessed. For the measurements of workers a NaI(Tl) EG and G ORTEC 905-1 were used in specific geometry, and data acquisition was controlled with Maestro TM software. Phantom has been used for calibration of efficiency of detectors placed in the same position as the real monitored person. Moreover, background counting was evaluated by statistical analysis for determination of protocol counting. The results obtained were analyzed under two models for calculating the decision threshold (Lc), and the minimum detectable activity (MDA), finally total uncertainty was calculated. Mean of efficiency was de 0.13% (RSD 6.7%) N = 43 D 6,7%, the MDA was 224 Bq (95% NC), and total propagated uncertainty was ± 13%. We obtained an effective evaluation of thyroid monitoring system for measurement of Iodine-131 in occupationally exposed persons. (author)

  12. New methodology developed for the differential scanning calorimetry analysis of polymeric matrixes incorporating phase change materials

    International Nuclear Information System (INIS)

    Barreneche, Camila; Solé, Aran; Miró, Laia; Martorell, Ingrid; Cabeza, Luisa F; Fernández, A Inés

    2012-01-01

    Nowadays, thermal comfort needs in buildings have led to an increase in energy consumption of the residential and service sectors. For this reason, thermal energy storage is shown as an alternative to achieve reduction of this high consumption. Phase change materials (PCM) have been studied to store energy due to their high storage capacity. A polymeric material capable of macroencapsulating PCM was developed by the authors of this paper. However, difficulties were found while measuring the thermal properties of these materials by differential scanning calorimetry (DSC). The polymeric matrix interferes in the detection of PCM properties by DSC. To remove this interfering effect, a new methodology which replaces the conventional empty crucible used as a reference in the DSC analysis by crucibles composed of the polymeric matrix was developed. Thus, a clear signal from the PCM is obtained by subtracting the new full crucible signal from the sample signal. (paper)

  13. Dielectric Barrier Discharge (DBD) Plasma Actuators Thrust-Measurement Methodology Incorporating New Anti-Thrust Hypothesis

    Science.gov (United States)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a large diameter, grounded, metal sleeve.

  14. Development, Characterization, and Optimization of Protein Level in Date Bars Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Muhammad Nadeem

    2012-01-01

    Full Text Available This project was designed to produce a nourishing date bar with commercial value especially for school going children to meet their body development requirements. Protein level of date bars was optimized using response surface methodology (RSM. Economical and underutilized sources, that is, whey protein concentrate and vetch protein isolates, were explored for protein supplementation. Fourteen date bar treatments were produced using a central composite design (CCD with 2 variables and 3 levels for each variable. Date bars were then analyzed for nutritional profile. Proximate composition revealed that addition of whey protein concentrate and vetch protein isolates improved the nutritional profile of date bars. Protein level, texture, and taste were considerably improved by incorporating 6.05% whey protein concentrate and 4.35% vetch protein isolates in date bar without affecting any sensory characteristics during storage. Response surface methodology was observed as an economical and effective tool to optimize the ingredient level and to discriminate the interactive effects of independent variables.

  15. Development of an aeroelastic methodology for surface morphing rotors

    Science.gov (United States)

    Cook, James R.

    Helicopter performance capabilities are limited by maximum lift characteristics and vibratory loading. In high speed forward flight, dynamic stall and transonic flow greatly increase the amplitude of vibratory loads. Experiments and computational simulations alike have indicated that a variety of active rotor control devices are capable of reducing vibratory loads. For example, periodic blade twist and flap excitation have been optimized to reduce vibratory loads in various rotors. Airfoil geometry can also be modified in order to increase lift coefficient, delay stall, or weaken transonic effects. To explore the potential benefits of active controls, computational methods are being developed for aeroelastic rotor evaluation, including coupling between computational fluid dynamics (CFD) and computational structural dynamics (CSD) solvers. In many contemporary CFD/CSD coupling methods it is assumed that the airfoil is rigid to reduce the interface by single dimension. Some methods retain the conventional one-dimensional beam model while prescribing an airfoil shape to simulate active chord deformation. However, to simulate the actual response of a compliant airfoil it is necessary to include deformations that originate not only from control devices (such as piezoelectric actuators), but also inertial forces, elastic stresses, and aerodynamic pressures. An accurate representation of the physics requires an interaction with a more complete representation of loads and geometry. A CFD/CSD coupling methodology capable of communicating three-dimensional structural deformations and a distribution of aerodynamic forces over the wetted blade surface has not yet been developed. In this research an interface is created within the Fully Unstructured Navier-Stokes (FUN3D) solver that communicates aerodynamic forces on the blade surface to University of Michigan's Nonlinear Active Beam Solver (UM/NLABS -- referred to as NLABS in this thesis). Interface routines are developed for

  16. Development of methodology for evaluation of 99mTc and 131I incorporated activities during lactation

    International Nuclear Information System (INIS)

    Santos, L.; Dantas, A.L.A.; Mesquita, S.A.; Oliveira, S.M.V.; Instituto de Radioprotecao e Dosimetria

    2012-01-01

    Internal contamination of babies may occur for milk ingestion or inhalation of mothers occupationally exposed to ionizing radiation with possible incorporation or mothers submitted to medical exposures during lactation. Radionuclide concentrations in the mother's milk may cause organ absorbed doses in the babies proportionally to the breast volumes. Milk analysis allow to determine activities ingested by the babies by determining the peak of mother's milk considering the decrease of the activity rate and the milk activities drunk at different time intervals. The work had the aim to develop simulators and methodology to evaluate 99m Tc and 131 I in lactation, in the following steps: to prepare standard solution of contaminated milk separately with 99m Tc and 131 I; to build four breast simulators (600 g and 800 g) and respective calibration for two geometries (breast and whole-body) in the Whole-Body Counter Unit in Instituto de Radioprotecao e Dosimetria. The results demonstrated the system efficiency to determine 99m Tc and 131 I activities in breasts during the lactation period. The methodology for positioning in the 'breast geometry' seemed to be more efficient than the 'whole-body geometry' for different breast volumes. The experiment allows achieving better evaluation of internal dosimetry of mothers and their young children. (author)

  17. A methodology to incorporate life cycle analysis and the triple bottom line mechanism for sustainable management of industrial enterprises

    Science.gov (United States)

    Wang, Ling; Lin, Li

    2004-02-01

    Since 1970"s, the environmental protection movement has challenged industries to increase their investment in Environmentally Conscious Manufacturing (ECM) techniques and management tools. Social considerations for global citizens and their descendants also motivated the examination on the complex issues of sustainable development beyond the immediate economic impact. Consequently, industrial enterprises have started to understand sustainable development in considering the Triple Bottom Line (TBL): economic prosperity, environmental quality and social justice. For the management, however, a lack of systematic ECM methodologies hinders their effort in planning, evaluating, reporting and auditing of sustainability. To address this critical need, this research develops a framework of a sustainable management system by incorporating a Life Cycle Analysis (LCA) of industrial operations with the TBL mechanism. A TBL metric system with seven sets of indices for the TBL elements and their complex relations is identified for the comprehensive evaluation of a company"s sustainability performance. Utilities of the TBL indices are estimated to represent the views of various stakeholders, including the company, investors, employees and the society at large. Costs of these indices are also captured to reflect the company"s effort in meeting the utilities. An optimization model is formulated to maximize the economic, environmental and social benefits by the company"s effort in developing sustainable strategies. To promote environmental and social consciousness, the methodology can significantly facilitate management decisions by its capabilities of including "non-business" values and external costs that the company has not contemplated before.

  18. Gold Incorporated Mesoporous Silica Thin Film Model Surface as a Robust SERS and Catalytically Active Substrate

    Directory of Open Access Journals (Sweden)

    Anandakumari Chandrasekharan Sunil Sekhar

    2016-05-01

    Full Text Available Ultra-small gold nanoparticles incorporated in mesoporous silica thin films with accessible pore channels perpendicular to the substrate are prepared by a modified sol-gel method. The simple and easy spin coating technique is applied here to make homogeneous thin films. The surface characterization using FESEM shows crack-free films with a perpendicular pore arrangement. The applicability of these thin films as catalysts as well as a robust SERS active substrate for model catalysis study is tested. Compared to bare silica film our gold incorporated silica, GSM-23F gave an enhancement factor of 103 for RhB with a laser source 633 nm. The reduction reaction of p-nitrophenol with sodium borohydride from our thin films shows a decrease in peak intensity corresponding to –NO2 group as time proceeds, confirming the catalytic activity. Such model surfaces can potentially bridge the material gap between a real catalytic system and surface science studies.

  19. Ab initio-based approach to reconstruction, adsorption and incorporation on GaN surfaces

    International Nuclear Information System (INIS)

    Ito, T; Akiyama, T; Nakamura, K

    2012-01-01

    Reconstruction, adsorption and incorporation on various GaN surfaces are systematically investigated using an ab initio-based approach that predicts the surface phase diagram as functions of temperature and beam-equivalent pressure (BEP). The calculated results for GaN surface reconstructions with polar (0 0 0 1), nonpolar (1 1 −2 0), semipolar (1 −1 0 1) and semipolar (1 1 −2 2) orientations imply that reconstructions on GaN surfaces with Ga adlayers generally appear on the polar and the semipolar surfaces, while the stable ideal surface without Ga adsorption is found on the nonpolar GaN(1 1 −2 0) surface because it satisfies the electron counting rule. The hydrogen adsorption on GaN(0 0 0 1) and GaN(1 1 −2 0) realizes several surface structures forming N–H and Ga–NH 2 bonds on their surfaces that depend on temperature and Ga BEP during metal-organic vapor-phase epitaxy (MOVPE). In contrast, the stable structures due to hydrogen adsorption on the semipolar GaN(1 −1 0 1) and GaN(1 1 −2 2) surfaces are not varied over the wide range of temperature and Ga BEP. This implies that the hydrogen adsorbed stable structures are expected to emerge on the semipolar surfaces during MOVPE regardless of the growth conditions. Furthermore, we clarify that Mg incorporation on GaN(1 −1 0 1) surfaces is enhanced by hydrogen adsorption consistent with experimental findings

  20. Effects of titanium surface anodization with CaP incorporation on human osteoblastic response

    Science.gov (United States)

    OLIVEIRA, Natássia Cristina Martins; MOURA, Camilla Christian Gomes; ZANETTA-BARBOSA, Darceny; MENDONÇA, Daniela Baccelli Silveira; MENDONÇA, Gustavo; DECHICHI, Paula

    2015-01-01

    In this study we investigated whether anodization with calcium phosphate (CaP) incorporation (Vulcano®) enhances growth factors secretion, osteoblast-specific gene expression, and cell viability, when compared to acid etched surfaces (Porous®) and machined surfaces (Screw®) after 3 and 7 days. Results showed significant cell viability for Porous and Vulcano at day 7, when compared with Screw (p=0.005). At the same time point, significant differences regarding runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and bone sialoprotein (BSP) expression were found for all surfaces (p0.05). Although no significant correlation was found for growth factors secretion and Runx2 expression, a significant positive correlation between this gene and ALP/BSP expression showed that their strong association is independent on the type of surface. The incorporation of CaP affected the biological parameters evaluated similar to surfaces just acid etched. The results presented here support the observations that roughness also may play an important role in determining cell response. PMID:23498218

  1. Production of specifically structured lipids by enzymatic interesterification in a pilot enzyme bed reactor: process optimization by response surface methodology

    DEFF Research Database (Denmark)

    Xu, Xuebing; Mu, Huiling; Høy, Carl-Erik

    1999-01-01

    Pilot production of specifically structured lipids by Lipozyme IM-catalyzed interesterification was carried out in a continuous enzyme bed reactor without the use of solvent. Medium chain triacylglycerols and oleic acid were used as model substrates. Response surface methodology was applied...... to optimize the reaction system with four process parameters, these being volume flow rate, water content in the substrates, reaction temperature and substrate ratio. The incorporation of acyl donors, product yields and the content of diacylglycerols were measured as the model responses. Enzyme activity...

  2. Design Methodology And Performance Studies Of A Flexible Electrotextile Surface

    Directory of Open Access Journals (Sweden)

    Kayacan Ozan

    2015-09-01

    Full Text Available ‘The smart textiles’ concept has to develop products based not only on design, fashion and comfort but also in terms of functions. The novel electro-textiles in the market open up new trends in smart and interactive gadgets. ‘Easy to care and durability’ properties are among the most important features of these products. On the other hand, wearable electronic knitwear has been gaining the attention of both researchers and industrial sectors. Combining knitting technology with electronics may become a dominant trend in the future because of the wide application possibilities. This research is concerned primarily with the design methodology of knitted fabrics containing electrically conductive textiles and especially in-use performance studies. The structural characteristics of the fabrics have been evaluated to enhance the performance properties.

  3. Application of response surface methodology optimization for the ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... of CQAs in tobacco waste were identified as three isomers containing chlorogenic acid (5-caffecylquinic acid ... Key words: Caffeic acid, caffeoylquinic acids (CQAs), hydrolysis reaction parameter optimization, response surface ..... Rosmarinic acid and caffeic acid produce antidepressive-like effect in.

  4. An Improved Response Surface Methodology Algorithm with an Application to Traffic Signal Optimization for Urban Networks

    Science.gov (United States)

    1995-01-01

    Prepared ca. 1995. This paper illustrates the use of the simulation-optimization technique of response surface methodology (RSM) in traffic signal optimization of urban networks. It also quantifies the gains of using the common random number (CRN) va...

  5. Stochastic response surface methodology: A study in the human health area

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Teresa A., E-mail: teresa.oliveira@uab.pt; Oliveira, Amílcar, E-mail: amilcar.oliveira@uab.pt [Departamento de Ciências e Tecnologia, Universidade Aberta (Portugal); Centro de Estatística e Aplicações, Universidade de Lisboa (Portugal); Leal, Conceição, E-mail: conceicao.leal2010@gmail.com [Departamento de Ciências e Tecnologia, Universidade Aberta (Portugal)

    2015-03-10

    In this paper we review Stochastic Response Surface Methodology as a tool for modeling uncertainty in the context of Risk Analysis. An application in the survival analysis in the breast cancer context is implemented with R software.

  6. Influence of the growth-surface on the incorporation of phosphorus in SiC

    International Nuclear Information System (INIS)

    Rauls, E.; Gerstmann, U.; Frauenheim, Th.

    2005-01-01

    Phosphorus is a common and desired n-type dopant of SiC, but it turned out that doping by diffusion or during growth is rarely successful. To avoid the efforts and the creation of damage if ion implantation is used instead, these techniques were, though, highly desirable. In this work, we have investigated theoretically the experimental observation that phosphorus obviously hardly diffuses into the material. Not the diffusivity of the dopant but its addiction to occupy a three-fold coordinated surface site are critical, together with the way the surface affects the bulk migration barriers of the dopants. Whereas the most common growth direction for 4H-SiC, the polar silicon terminated (0001) surface, seems to be least appropriate for the incorporation of phosphorus atoms, growth along the nonpolar [112-bar 0] provides a good possibility to achieve efficient P-doping during growth

  7. Antibacterial and microstructure properties of titanium surfaces modified with Ag-incorporated nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guangzhong; Cheng, Li [State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research (China); Yang, Hui-lin [Department of Orthopaedics, Wuxi People' s Hospital, Nanjing Medical University, Jiangsu Province (China); Zhao, Quan-ming, E-mail: abc8385@163.com [Department of Orthopaedics, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2016-07-15

    Although titanium (Ti) and its alloys have been widely used as implants in clinical settings, failures still occur mainly due to poor bioactivity and implant-associated infections. Here, we coated Ti implants with TiO{sub 2} nanotubes (TNTs) incorporated with the antibacterial agent Ag to produce Ag-TNTs, through anodization in AgNO{sub 3} and xenon light irradiation. We characterized surface morphology and composition of the coating with scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. We investigated surface topography of the coatings by atomic force microscopy (AFM) operated in the tapping mode. The results indicate that Ag was successfully doped onto the TNTs, and that the nanoparticles were mainly distributed on the surface of TNTs. Finally, our antibacterial experiments reveal that Ag-TNTs on Ti implants exhibit excellent antibacterial activities, which promises to have significant clinical applications as implants. (author)

  8. How to Select the most Relevant Roughness Parameters of a Surface: Methodology Research Strategy

    Science.gov (United States)

    Bobrovskij, I. N.

    2018-01-01

    In this paper, the foundations for new methodology creation which provides solving problem of surfaces structure new standards parameters huge amount conflicted with necessary actual floors quantity of surfaces structure parameters which is related to measurement complexity decreasing are considered. At the moment, there is no single assessment of the importance of a parameters. The approval of presented methodology for aerospace cluster components surfaces allows to create necessary foundation, to develop scientific estimation of surfaces texture parameters, to obtain material for investigators of chosen technological procedure. The methods necessary for further work, the creation of a fundamental reserve and development as a scientific direction for assessing the significance of microgeometry parameters are selected.

  9. Incorporating classic adsorption isotherms into modern surface complexation models: implications for sorption of radionuclides

    International Nuclear Information System (INIS)

    Kulik, D.A.

    2005-01-01

    Full text of publication follows: Computer-aided surface complexation models (SCM) tend to replace the classic adsorption isotherm (AI) analysis in describing mineral-water interface reactions such as radionuclide sorption onto (hydr) oxides and clays. Any site-binding SCM based on the mole balance of surface sites, in fact, reproduces the (competitive) Langmuir isotherm, optionally amended with electrostatic Coulomb's non-ideal term. In most SCM implementations, it is difficult to incorporate real-surface phenomena (site heterogeneity, lateral interactions, surface condensation) described in classic AI approaches other than Langmuir's. Thermodynamic relations between SCMs and AIs that remained obscure in the past have been recently clarified using new definitions of standard and reference states of surface species [1,2]. On this basis, a method for separating the Langmuir AI into ideal (linear) and non-ideal parts [2] was applied to multi-dentate Langmuir, Frumkin, and BET isotherms. The aim of this work was to obtain the surface activity coefficient terms that make the SCM site mole balance constraints obsolete and, in this way, extend thermodynamic SCMs to cover sorption phenomena described by the respective AIs. The multi-dentate Langmuir term accounts for the site saturation with n-dentate surface species, as illustrated on modeling bi-dentate U VI complexes on goethite or SiO 2 surfaces. The Frumkin term corrects for the lateral interactions of the mono-dentate surface species; in particular, it has the same form as the Coulombic term of the constant-capacitance EDL combined with the Langmuir term. The BET term (three parameters) accounts for more than a monolayer adsorption up to the surface condensation; it can potentially describe the surface precipitation of nickel and other cations on hydroxides and clay minerals. All three non-ideal terms (in GEM SCMs implementation [1,2]) by now are used for non-competing surface species only. Upon 'surface dilution

  10. Current status and new trends in the methodology of safety assessment for near surface disposal facilities

    International Nuclear Information System (INIS)

    Ilie, Petre; Didita, Liana; Danchiv, Alexandru

    2008-01-01

    The main goal of this paper is to present the status of the safety assessment methodology at the end of IAEA CRP 'Application of Safety Assessment Methodology for Near-Surface Radioactive Waste Disposal Facilities (ASAM)', and the new trends outlined at the launch of the follow-up project 'Practical Implementation of Safety Assessment Methodologies in a Context of Safety Case of Near-Surface Facilities (PRISM)'. Over the duration of the ASAM project, the ISAM methodology was confirmed as providing a good framework for conducting safety assessment calculations. In contrast, ASAM project identified the limitations of the ISAM methodology as currently formulated. The major limitations are situated in the area of the use of safety assessment for informing practical decisions about alternative waste and risk management strategies for real disposal sites. As a result of the limitation of the ISAM methodology, the PRISM project is established as an extension of the ISAM and ASAM projects. Based on the outcomes of the ASAM project, the main objective of the PRISM project are: 1 - to develop an overview of what constitutes an adequate safety case and safety assessment with a view to supporting decision making processes; 2 - to provide practical illustrations of how the safety assessment methodology could be used for addressing some specific issues arising from the ASAM project and national cases; 3 - to support harmonization with the IAEA's international safety standards. (authors)

  11. Ultra-high vacuum surface analysis study of rhodopsin incorporation into supported lipid bilayers.

    Science.gov (United States)

    Michel, Roger; Subramaniam, Varuni; McArthur, Sally L; Bondurant, Bruce; D'Ambruoso, Gemma D; Hall, Henry K; Brown, Michael F; Ross, Eric E; Saavedra, S Scott; Castner, David G

    2008-05-06

    Planar supported lipid bilayers that are stable under ambient atmospheric and ultra-high-vacuum conditions were prepared by cross-linking polymerization of bis-sorbylphosphatidylcholine (bis-SorbPC). X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were employed to investigate bilayers that were cross-linked using either redox-initiated radical polymerization or ultraviolet photopolymerization. The redox method yields a more structurally intact bilayer; however, the UV method is more compatible with incorporation of transmembrane proteins. UV polymerization was therefore used to prepare cross-linked bilayers with incorporated bovine rhodopsin, a light-activated, G-protein-coupled receptor (GPCR). A previous study (Subramaniam, V.; Alves, I. D.; Salgado, G. F. J.; Lau, P. W.; Wysocki, R. J.; Salamon, Z.; Tollin, G.; Hruby, V. J.; Brown, M. F.; Saavedra, S. S. J. Am. Chem. Soc. 2005, 127, 5320-5321) showed that rhodopsin retains photoactivity after incorporation into UV-polymerized bis-SorbPC, but did not address how the protein is associated with the bilayer. In this study, we show that rhodopsin is retained in supported bilayers of poly(bis-SorbPC) under ultra-high-vacuum conditions, on the basis of the increase in the XPS nitrogen concentration and the presence of characteristic amino acid peaks in the ToF-SIMS data. Angle-resolved XPS data show that the protein is inserted into the bilayer, rather than adsorbed on the bilayer surface. This is the first study to demonstrate the use of ultra-high-vacuum techniques for structural studies of supported proteolipid bilayers.

  12. Hepatitis B surface antigen incorporated in dissolvable microneedle array patch is antigenic and thermostable.

    Science.gov (United States)

    Poirier, Danielle; Renaud, Frédéric; Dewar, Vincent; Strodiot, Laurent; Wauters, Florence; Janimak, Jim; Shimada, Toshio; Nomura, Tatsuya; Kabata, Koki; Kuruma, Koji; Kusano, Takayuki; Sakai, Masaki; Nagasaki, Hideo; Oyamada, Takayoshi

    2017-11-01

    Alternatives to syringe-based administration are considered for vaccines. Intradermal vaccination with dissolvable microneedle arrays (MNA) appears promising in this respect, as an easy-to-use and painless method. In this work, we have developed an MNA patch (MNAP) made of hydroxyethyl starch (HES) and chondroitin sulphate (CS). In swines, hepatitis B surface antigen (HBsAg) formulated with the saponin QS-21 as adjuvant, both incorporated in HES-based MNAP, demonstrated the same level of immunogenicity as a commercially available aluminum-adjuvanted HBsAg vaccine, after two immunizations 28 days apart. MNAP application was associated with transient skin reactions (erythema, lump, scab), particularly evident when the antigen was delivered with the adjuvant. The thermostability of the adjuvanted antigen when incorporated in the HES-based matrix was also assessed by storing MNAP at 37, 45 or 50 °C for up to 6 months. We could demonstrate that antigenicity was retained at 37 and 45 °C and only a 10% loss was observed after 6 months at 50 °C. Our results are supportive of MNAP as an attractive alternative to classical syringe-based vaccination. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Synthesis of structured triacylglycerols containing caproic acid by lipase-catalyzed acidolysis: Optimization by response surface methodology

    DEFF Research Database (Denmark)

    Zhou, D.Q.; Xu, Xuebing; Mu, Huiling

    2001-01-01

    Production in a batch reactor with a solvent-free system of structured triacylglycerols containing short-chain fatty acids by Lipozyme RM IM-catalyzed acidolysis between rapeseed oil and caproic acid was optimized using response surface methodology (RSM). Reaction time (t(r)), substrate ratio (S......-r), enzyme load (E-1, based on substrate), water content (W-c, based on enzyme), and reaction temperature (T-e), the five most important parameters for the reaction, were chosen for the optimization. The range of each parameter was selected as follows: t(r) = 5-17 h; E-1 = 6-14 wt %; T-e = 45-65 degreesC; S......-incorporated structured triacylglycerols were also evaluated. The optimal reaction conditions for the incorporation of caproic acid and the content of di-incorporated structured triacylglycerols were as follows: t(r) = 17 h; 8, = 5; E-1 = 14 wt %; W-c = 10 wt %; T-e = 65 degreesC. At these conditions, products with 55...

  14. Influence of activated carbon characteristics on toluene and hexane adsorption: Application of surface response methodology

    Science.gov (United States)

    Izquierdo, Mª Teresa; de Yuso, Alicia Martínez; Valenciano, Raquel; Rubio, Begoña; Pino, Mª Rosa

    2013-01-01

    The objective of this study was to evaluate the adsorption capacity of toluene and hexane over activated carbons prepared according an experimental design, considering as variables the activation temperature, the impregnation ratio and the activation time. The response surface methodology was applied to optimize the adsorption capacity of the carbons regarding the preparation conditions that determine the physicochemical characteristics of the activated carbons. The methodology of preparation produced activated carbons with surface areas and micropore volumes as high as 1128 m2/g and 0.52 cm3/g, respectively. Moreover, the activated carbons exhibit mesoporosity, ranging from 64.6% to 89.1% the percentage of microporosity. The surface chemistry was characterized by TPD, FTIR and acid-base titration obtaining different values of surface groups from the different techniques because the limitation of each technique, but obtaining similar trends for the activated carbons studied. The exhaustive characterization of the activated carbons allows to state that the measured surface area does not explain the adsorption capacity for either toluene or n-hexane. On the other hand, the surface chemistry does not explain the adsorption results either. A compromise between physical and chemical characteristics can be obtained from the appropriate activation conditions, and the response surface methodology gives the optimal activated carbon to maximize adsorption capacity. Low activation temperature, intermediate impregnation ratio lead to high toluene and n-hexane adsorption capacities depending on the activation time, which a determining factor to maximize toluene adsorption.

  15. Geo-ecology of surface atmosphere of Tomsk and methodology for the ecological risk calculation

    Science.gov (United States)

    Ivanova, E. V.; Anisimov, M. V.; Kuznetsova, U. N.; Taldonova, N. V.; Petrova, A. V.

    2018-01-01

    The present study presents new methodological approach of environmental assessment of surface atmosphere layer based on principles of non equilibrium dynamics. The role of natural and technogenic factors in forming areas of dust and airborne pollution is determined. The results of the study of ecological risk from atmosphere chemical pollution of the town are presented.

  16. Simultaneous saccharification and ethanol fermentation of oxalic acid pretreated corncob assessed with response surface methodology

    Science.gov (United States)

    Jae-Won Lee; Rita C.L.B. Rodrigues; Thomas W. Jeffries

    2009-01-01

    Response surface methodology was used to evaluate optimal time, temperature and oxalic acid concentration for simultaneous saccharification and fermentation (SSF) of corncob particles by Pichia stipitis CBS 6054. Fifteen different conditions for pretreatment were examined in a 23 full factorial design with six axial points. Temperatures ranged from 132 to 180º...

  17. Optimization of lysine production in Corynebacteriumglutamicum ATCC15032 by Response surface methodology

    Directory of Open Access Journals (Sweden)

    Mehrnaz Haghi

    2017-03-01

    Discussion and conclusion: According to the results, the proposed culture media by response surface methodology causes 1400 times increase in the lysine production compared with M9 culture media and methionine had an important role in the production of lysine, probably by inhibiting the other metabolic pathway which has common metabolic precursor with lysine production metabolic pathway.

  18. SU-E-T-489: Incorporating Skin Flash Into VMAT WBI: Impacts On Surface Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Buele, A Bejarano; Tanny, S; Warrell, G; Parsai, E [University of Toledo Medical Center, Toledo, OH (United States)

    2015-06-15

    Purpose: Increased use of inverse planning limits the amount of skin flash in whole breast irradiation (WBI). Strategies to incorporate flash into inverse-planned treatments involve overriding air to the density of water or tissue. This introduces uncertainties to the superficial dose distribution, potentially degrading the coverage at the skin-bolus interface. We investigate the accuracy of various commonly used bolus materials to incorporate flash in VMAT WBI plans while minimizing the perturbation near the skin. Methods: We obtained a CT-simulation of an anthropomorphic phantom with a breast attachment. Three VMAT plans were created with different boluses: 1 cm of 1 g/cm{sup 3} bolus (Superflab), 1 cm of 0.65 g/cm{sup 3} bolus (wet towels), and 1 cm of g/cm{sup 3} bolus with 2 dose levels accounting for the difference between bolus and tissue density. The PTV was extended into the bolus, outside the patient body contour to incorporate flash. OSLDs were used to obtain surface doses at the medial, lateral and tip sites of the breast. Each plan was irradiated four times using CBCT for positioning and dosimeter localization. Results: The average thickness of the wet-towel bolus on delivery was 8 mm with a CBCT-measured density of 0.6 g/cm{sup 3}. OSLD measurements demonstrated good agreement with predicted doses from Pinnacle. Average deviations were −5.7%, −2.5%, and −2.6% for plans 1, 2, and 3, respectively. OSLDs placed at the medial and lateral portions of the breast showed the largest average deviations. The maximum recorded deviation from planned values was −8.6%. The largest dose fluctuations occurred near areas where the bolus failed to properly conform to the breast contour. Conclusion: Use of wet-towel bolus improved dose delivery accuracy compared to standard Superflab bolus. Areas of poor bolus conformity adversely affected dose delivery. We recommend the use of wet-towel bolus over Superflab bolus for VMAT WBI.

  19. The IAEA research project on improvement of safety assessment methodologies for near surface disposal facilities

    International Nuclear Information System (INIS)

    Torres-Vidal, C.; Graham, D.; Batandjieva, B.

    2002-01-01

    The International Atomic Energy Agency (IAEA) Research Coordinated Project on Improvement of Safety Assessment Methodologies for Near Surface Disposal Facilities (ISAM) was launched in November 1997 and it has been underway for three years. The ISAM project was developed to provide a critical evaluation of the approaches and tools used in long-term safety assessment of near surface repositories. It resulted in the development of a harmonised approach and illustrated its application by way of three test cases - vault, borehole and Radon (a particular range of repository designs developed within the former Soviet Union) type repositories. As a consequence, the ISAM project had over 70 active participants and attracted considerable interest involving around 700 experts from 72 Member States. The methodology developed, the test cases, the main lessons learnt and the conclusions have been documented and will be published in the form of an IAEA TECDOC. This paper presents the work of the IAEA on improvement of safety assessment methodologies for near surface waste disposal facilities and the application of these methodologies for different purposes in the individual stages of the repository development. The paper introduces the main objectives, activities and outcome of the ISAM project and summarizes the work performed by the six working groups within the ISAM programme, i.e. Scenario Generation and Justification, Modelling, Confidence Building, Vault, Radon Type Facility and Borehole test cases. (author)

  20. Enhanced Sensitivity of Surface Acoustic Wave-Based Rate Sensors Incorporating Metallic Dot Arrays

    Directory of Open Access Journals (Sweden)

    Wen Wang

    2014-02-01

    Full Text Available A new surface acoustic wave (SAW-based rate sensor pattern incorporating metallic dot arrays was developed in this paper. Two parallel SAW delay lines with a reverse direction and an operation frequency of 80 MHz on a same X-112°Y LiTaO3 wafer are fabricated as the feedback of two SAW oscillators, and mixed oscillation frequency was used to characterize the external rotation. To enhance the Coriolis force effect acting on the SAW propagation, a copper (Cu dot array was deposited along the SAW propagation path of the SAW devices. The approach of partial-wave analysis in layered media was referred to analyze the response mechanisms of the SAW based rate sensor, resulting in determination of the optimal design parameters. To improve the frequency stability of the oscillator, the single phase unidirectional transducers (SPUDTs and combed transducer were used to form the SAW device to minimize the insertion loss and accomplish the single mode selection, respectively. Excellent long-term (measured in hours frequency stability of 0.1 ppm/h was obtained. Using the rate table with high precision, the performance of the developed SAW rate sensor was evaluated experimentally; satisfactory detection sensitivity (16.7 Hz∙deg∙s−1 and good linearity were observed.

  1. A simple statistical method for analyzing flood susceptibility with incorporating rainfall and impervious surface

    Science.gov (United States)

    Chiang, Shou-Hao; Chen, Chi-Farn

    2016-04-01

    Flood, as known as the most frequent natural hazard in Taiwan, has induced severe damages of residents and properties in urban areas. The flood risk is even more severe in Tainan since 1990s, with the significant urban development over recent decades. Previous studies have indicated that the characteristics and the vulnerability of flood are affected by the increase of impervious surface area (ISA) and the changing climate condition. Tainan City, in southern Taiwan is selected as the study area. This study uses logistic regression to functionalize the relationship between rainfall variables, ISA and historical flood events. Specifically, rainfall records from 2001 to 2014 were collected and mapped, and Landsat images of year 2001, 2004, 2007, 2010 and 2014 were used to generate the ISA with SVM (support vector machine) classifier. The result shows that rainfall variables and ISA are significantly correlated to the flood occurrence in Tainan City. With applying the logistic function, the likelihood of flood occurrence can be estimated and mapped over the study area. This study suggests the method is simple and feasible for rapid flood susceptibility mapping, when real-time rainfall observations can be available, and it has potential for future flood assessment, with incorporating climate change projections and urban growth prediction.

  2. Application of Response Surface Methodology in Optimizing a Three Echelon Inventory System

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Razavi Hajiagha

    2014-01-01

    Full Text Available Inventory control is an important subject in supply chain management. In this paper, a three echelon production, distribution, inventory system composed of one producer, two wholesalers and a set of retailers has been considered. Costumers' demands follow a compound Poisson process and the inventory policy is a kind of continuous review (R, Q. In this paper, regarding the standard cost structure in an inventory model, the cost function of system has been approximated using Response Surface Methodology as a combination of designed experiments, simulation, regression analysis and optimization. The proposed methodology in this paper can be applied as a novel method in optimization of inventory policy of supply chains. Also, the joint optimization of inventory parameters, including reorder point and batch order size, is another advantage of the proposed methodology.

  3. A dual response surface optimization methodology for achieving uniform coating thickness in powder coating process

    Directory of Open Access Journals (Sweden)

    Boby John

    2015-09-01

    Full Text Available The powder coating is an economic, technologically superior and environment friendly painting technique compared with other conventional painting methods. However large variation in coating thickness can reduce the attractiveness of powder coated products. The coating thickness variation can also adversely affect the surface appearance and corrosion resistivity of the product. This can eventually lead to customer dissatisfaction and loss of market share. In this paper, the author discusses a dual response surface optimization methodology to minimize the thickness variation around the target value of powder coated industrial enclosures. The industrial enclosures are cabinets used for mounting the electrical and electronic equipment. The proposed methodology consists of establishing the relationship between the coating thickness & the powder coating process parameters and developing models for the mean and variance of coating thickness. Then the powder coating process is optimized by minimizing the standard deviation of coating thickness subject to the constraint that the thickness mean would be very close to the target. The study resulted in achieving a coating thickness mean of 80.0199 microns for industrial enclosures, which is very close to the target value of 80 microns. A comparison of the results of the proposed approach with that of existing methodologies showed that the suggested method is equally good or even better than the existing methodologies. The result of the study is also validated with a new batch of industrial enclosures.

  4. Incorporating Variational Local Analysis and Prediction System (vLAPS) Analyses with Nudging Data Assimilation: Methodology and Initial Results

    Science.gov (United States)

    2017-09-01

    YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD‐MM‐YYYY)  September 2017 2. REPORT  TYPE   Technical Report 3. DATES COVERED (From ‐ To)  July...is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT  The potential value of combining 2 data assimilation methodologies to improve mesoscale...the ability to assimilate a wide variety of observation types gained from vLAPS. Multiple cycles of 1-km horizontal grid spacing forecasts of the

  5. A strontium-incorporated nanoporous titanium implant surface for rapid osseointegration

    Science.gov (United States)

    Zhang, Wenjie; Cao, Huiliang; Zhang, Xiaochen; Li, Guanglong; Chang, Qing; Zhao, Jun; Qiao, Yuqin; Ding, Xun; Yang, Guangzheng; Liu, Xuanyong; Jiang, Xinquan

    2016-02-01

    Rapid osseointegration of dental implants will shorten the period of treatment and enhance the comfort of patients. Due to the vital role of angiogenesis played during bone development and regeneration, it might be feasible to promote rapid osseointegration by modifying the implant surface to gain a combined angiogenesis/osteogenesis inducing capacity. In this study, a novel coating (MAO-Sr) with strontium-incorporated nanoporous structures on titanium implants was generated via a new micro-arc oxidation, in an attempt to induce angiogenesis and osteogenesis to enhance rapid osseointegration. In vitro, the nanoporous structure significantly enhanced the initial adhesion of canine BMSCs. More importantly, sustained release of strontium ions also displayed a stronger effect on the BMSCs in facilitating their osteogenic differentiation and promoting the angiogenic growth factor secretion to recruit endothelial cells and promote blood vessel formation. Advanced mechanism analyses indicated that MAPK/Erk and PI3K/Akt signaling pathways were involved in these effects of the MAO-Sr coating. Finally, in the canine dental implantation study, the MAO-Sr coating induced faster bone formation within the initial six weeks and the osseointegration effect was comparable to that of the commercially available ITI implants. These results suggest that the MAO-Sr coating has the potential for future use in dental implants.Rapid osseointegration of dental implants will shorten the period of treatment and enhance the comfort of patients. Due to the vital role of angiogenesis played during bone development and regeneration, it might be feasible to promote rapid osseointegration by modifying the implant surface to gain a combined angiogenesis/osteogenesis inducing capacity. In this study, a novel coating (MAO-Sr) with strontium-incorporated nanoporous structures on titanium implants was generated via a new micro-arc oxidation, in an attempt to induce angiogenesis and osteogenesis to

  6. [Optimization of one-step pelletization technology of Jiuwei Xifeng granules by response surface methodology].

    Science.gov (United States)

    Wang, Xiu-hai; Yang, Xu-fang; Fan, Ye-wen; Zhang, Yan-jun; Xu, Zhong-kun; Yang, Lin-yong; Wang, Zhen-zhong; Xiao, Wei

    2014-12-01

    Using the qualified rates of particles as the evaluation indexes, the impact tactors of one-step pelletization technology of Jiuwei Xifeng granules were selected from six factors by the Plackett-Burman experimental design and the levels of non-significant factors were identified. According to the Plackett-Burman experimental design, choosing the qualified rates of particles and angle of repose as the evaluation indexes, three levels of the three factors were selected by Box-Behnken of central composite design to optimize the experimental. The best conditions were as follows: the fluid extract was sprayed with frequency of 29 r . min-1, inlet air temperature was 90 °C, the frequency of fan was 34 Hz. Under the response surface methodology optimized scheme, the average experimental results are similar to the predicted values, and surface methodology could be used in the optimization of one-step pelletization for Chinese materia medica.

  7. Gas migration from closed coal mines to the surface. Risk assessment methodology and prevention means

    International Nuclear Information System (INIS)

    Pokryszka, Z.; Tauziede, Ch.; Lagny, C.; Guise, Y.; Gobillot, R.; Planchenault, J.M.; Lagarde, R.

    2005-01-01

    French law as regards renunciation to mining concessions calls for the mining operator to first undertake analyses of the risks represented by their underground mining works. The problem of gas migration to the surface is especially significant in the context of coal mines. This is because mine gas can migrate to the earth's surface, then present significant risks: explosion, suffocation or gas poisoning risks. As part of the scheduled closure of all coal mining operations in France, INERIS has drawn up, at the request of national mining operator Charbonnages de France, a general methodology for assessing the risk linked to gas in the context of closed coal mines. This article presents the principles of this methodology. An application example based on a true case study is then described. This is completed by a presentation of the preventive and monitoring resources recommended and usually applied in order to manage the risk linked to gaseous emissions. (authors)

  8. Evaluation of electro-oxidation of biologically treated landfill leachate using response surface methodology

    International Nuclear Information System (INIS)

    Zhang Hui; Ran Xiaoni; Wu Xiaogang; Zhang Daobin

    2011-01-01

    Box-Behnken statistical experiment design and response surface methodology were used to investigate electrochemical oxidation of mature landfill leachate pretreated by sequencing batch reactor (SBR). Titanium coated with ruthenium dioxide (RuO 2 ) and iridium dioxide (IrO 2 ) was used as the anode in this study. The variables included current density, inter-electrode gap and reaction time. Response factors were ammonia nitrogen removal efficiency and COD removal efficiency. The response surface methodology models were derived based on the results. The predicted values calculated with the model equations were very close to the experimental values and the models were highly significant. The organic components before and after electrochemical oxidation were determined by GC-MS.

  9. Optimization of Ultrasonic Extraction of Phenolic Antioxidants from Green Tea Using Response Surface Methodology

    OpenAIRE

    Lee, Lan-Sook; Lee, Namhyouck; Kim, Young; Lee, Chang-Ho; Hong, Sang; Jeon, Yeo-Won; Kim, Young-Eon

    2013-01-01

    Response surface methodology (RSM) has been used to optimize the extraction conditions of antioxidants with relatively low caffeine content from green tea by using ultrasonic extraction. The predicted optimal conditions for the highest antioxidant activity and minimum caffeine level were found at 19.7% ethanol, 26.4 min extraction time, and 24.0 °C extraction temperature. In the predicted optimal conditions, the experimental values were very close to the predicted values. Moreover, the ratio ...

  10. Extraction optimization of mucilage from Basil (Ocimum basilicum L.) seeds using response surface methodology

    OpenAIRE

    Sadaf Nazir; Idrees Ahmed Wani; Farooq Ahmad Masoodi

    2017-01-01

    Aqueous extraction of basil seed mucilage was optimized using response surface methodology. A Central Composite Rotatable Design (CCRD) for modeling of three independent variables: temperature (40?91??C); extraction time (1.6?3.3?h) and water/seed ratio (18:1?77:1) was used to study the response for yield. Experimental values for extraction yield ranged from 7.86 to 20.5?g/100?g. Extraction yield was significantly (P?

  11. Efficient surrogate construction by combining response surface methodology and reduced order modeling

    OpenAIRE

    Gogu , Christian; Passieux , Jean-Charles

    2012-01-01

    International audience; Response surface methodology is an efficient method for approximating the output of complex, computationally expensive codes. Challenges remain however in decreasing their construction cost as well as in approximating high dimensional output instead of scalar values. We propose a novel approach addressing both these challenges simultaneously for cases where the expensive code solves partial differential equations involving the resolution of a large system of equations,...

  12. Optimization of lead adsorption of mordenite by response surface methodology: characterization and modification

    OpenAIRE

    Turkyilmaz, Havva; Kartal, Tolga; Yigitarslan Yildiz, Sibel

    2014-01-01

    Background In order to remove heavy metals, water treatment by adsorption of zeolite is gaining momentum due to low cost and good performance. In this research, the natural mordenite was used as an adsorbent to remove lead ions in an aqueous solution. Methods The effects of adsorption temperature, time and initial concentration of lead on the adsorption yield were investigated. Response surface methodology based on Box-Behnken design was applied for optimization. Adsorption data were analyzed...

  13. Modeling of Bisphenol A (BPA) Removal from Aqueous Solutions by Adsorption Using Response Surface Methodology (RSM)

    OpenAIRE

    Mohammad Ali Zazouli; Farzaneh Veisi; Amir Veisi

    2016-01-01

    Bisphenol A (BPA) is an organic synthetic compound that has many applications in various industries and is known as persistent pollutant. The aim of this research was to evaluate the efficiency of bone ash and banana peel as adsorbents for BPA adsorption from aqueous solution by using Response Surface Methodology. The effects of some variables such as sorbent dose, detention time, solution pH, and BPA concentration on the sorption efficiency was examined. All analyses were carried out accordi...

  14. Modeling and optimization of ammonia treatment by acidic biochar using response surface methodology

    OpenAIRE

    Narong Chaisongkroh; Juntima Chungsiriporn; Charun Bunyakan

    2012-01-01

    Emission of ammonia (NH3) contaminated waste air to the atmosphere without treatment has affected humans andenvironment. Eliminating NH3 in waste air emitted from industries is considered an environmental requisite. In this study,optimization of NH3 adsorption time using acidic rubber wood biochar (RWBs) impregnated with sulfuric acid (H2SO4) wasinvestigated. The central composite design (CCD) in response surface methodology (RSM) by the Design Expert softwarewas used for designing the experi...

  15. Wrinkling Prediction in Deep Drawing by Using Response Surface Methodology and Artificial Neural Network

    OpenAIRE

    Rafizadeh, Hossein; Azimifar, Farhad; Foode, Puya; Foudeh, Mohammad Reza; Keymanesh, Mohammad

    2017-01-01

    The objective of this study is to predict influences of tooling parameters such as die and punch radius, blank holder force and friction coefficient between the die and the blank surfaces in a deep drawing process on the wrinkling height in aluminium AA5754 by using the response surface methodology (RSM) and an artificial neural network (ANN). The 3D finite element method (FEM), i.e. the Abaqus software, is employed to model the deep drawing process. In order to investigate the accuracy of th...

  16. Optimization of the extraction of flavonoids from grape leaves by response surface methodology

    International Nuclear Information System (INIS)

    Brad, K.; Liu, W.

    2013-01-01

    The extraction of flavonoids from grape leaves was optimized to maximize flavonoids yield in this study. A central composite design of response surface methodology involving extracting time, power, liquid-solid ratio, and concentration was used, and second-order model for Y was employed to generate the response surfaces. The optimum condition for flavonoids yield was determined as follows: extracting time 24.95 min, power 72.05, ethanol concentration 63.35%, liquid-solid ratio 10.04. Under the optimum condition, the flavonoids yield was 76.84 %. (author)

  17. Calculation of t8/5 by response surface methodology for electric arc welding applications

    Directory of Open Access Journals (Sweden)

    Meseguer-Valdenebro José Luis

    2014-01-01

    Full Text Available One of the greatest difficulties traditionally found in stainless steel constructions has been the execution of welding parts in them. At the present time, the available technology allows us to use arc welding processes for that application without any disadvantage. Response surface methodology is used to optimise a process in which the variables that take part in it are not related to each other by a mathematical law. Therefore, an empiric model must be formulated. With this methodology the optimisation of one selected variable may be done. In this work, the cooling time that takes place from 800 to 500ºC, t8/5, after TIG welding operation, is modelled by the response surface method. The arc power, the welding velocity and the thermal efficiency factor are considered as the variables that have influence on the t8/5 value. Different cooling times,t8/5, for different combinations of values for the variables are previously determined by a numerical method. The input values for the variables have been experimentally established. The results indicate that response surface methodology may be considered as a valid technique for these purposes.

  18. Medium Optimization for 5’-Phosphodiesterase Production from Penicillium citrinum Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Lu-E Shi

    2007-01-01

    Full Text Available Medium optimization for 5’-phosphodiesterase production from Penicillium citrinum was studied by applying one-factor-at-a-time method, orthogonal array method and response surface methodology in this paper. The one-factor-at-a-time method was used to study the effects of carbon, nitrogen, phosphorus and metal ion sources on 5’-phosphodiesterase production. Among various carbon and nitrogen sources used, glucose and peptone were the most suitable substances for 5’-phosphodiesterase production, respectively. Subsequently, the concentrations of glucose, peptone, groundnut meal, Zn2+ and KH2PO4 were optimized using the orthogonal array method. Response surface methodology was also applied for medium optimization. Glucose concentration (X1, peptone concentration (X2 and groundnut meal (X3 were selected as the independent variables. Results showed that the regression models adequately explained the data variation and represented the actual relationships between the parameters and responses. The optimum conditions were glucose at a fraction of 6.5 %, peptone at a fraction of 0.45 % and groundnut meal at a fraction of 1.0 %. Maximum enzyme activity was 353 U/mL under the optimum conditions. Maximum 5’-phosphodiesterase activity in media optimized by orthogonal method and response surface methodology was about 1.286 and 1.456 times, respectively, greater than in the medium optimized by one-factor-at-a-time method.

  19. Bacterial production of site specific {sup 13}C labeled phenylalanine and methodology for high level incorporation into bacterially expressed recombinant proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ramaraju, Bhargavi; McFeeters, Hana; Vogler, Bernhard; McFeeters, Robert L., E-mail: robert.mcfeeters@uah.edu [University of Alabama in Huntsville, Department of Chemistry (United States)

    2017-01-15

    Nuclear magnetic resonance spectroscopy studies of ever larger systems have benefited from many different forms of isotope labeling, in particular, site specific isotopic labeling. Site specific {sup 13}C labeling of methyl groups has become an established means of probing systems not amenable to traditional methodology. However useful, methyl reporter sites can be limited in number and/or location. Therefore, new complementary site specific isotope labeling strategies are valuable. Aromatic amino acids make excellent probes since they are often found at important interaction interfaces and play significant structural roles. Aromatic side chains have many of the same advantages as methyl containing amino acids including distinct {sup 13}C chemical shifts and multiple magnetically equivalent {sup 1}H positions. Herein we report economical bacterial production and one-step purification of phenylalanine with {sup 13}C incorporation at the Cα, Cγ and Cε positions, resulting in two isolated {sup 1}H-{sup 13}C spin systems. We also present methodology to maximize incorporation of phenylalanine into recombinantly overexpressed proteins in bacteria and demonstrate compatibility with ILV-methyl labeling. Inexpensive, site specific isotope labeled phenylalanine adds another dimension to biomolecular NMR, opening new avenues of study.

  20. Comparison of different pathways in metamorphic graded buffers on GaAs substrate: Indium incorporation with surface roughness

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rahul, E-mail: rkp203@gmail.com [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Mukhopadhyay, P. [Rajendra Mishra School of Engineering Entrepreneurship, Indian Institute of Technology, Kharagpur 721302 (India); Bag, A.; Jana, S. Kr. [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Chakraborty, A. [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721 302 (India); Das, S.; Mahata, M. Kr. [Advanced Technology Development Centre, Indian Institute of Technology, Kharagpur 721302 (India); Biswas, D. [Department of Electronics and Electrical Communication Engineering, Indian Institute of Technology, Kharagpur 721 302 (India)

    2015-01-01

    Highlights: • In(Al,Ga)As metamorphic buffers on GaAs have been grown. • Surface morphology, strain relaxation and compositional variation have been studied. • Al containing buffers shows inferior surface roughness. • Surface roughness modulates the indium incorporation rate. - Abstract: In this work, compositionally graded In(Al,Ga)As metamorphic buffers (MBs) on GaAs substrate have been grown by MBE through three different paths. A comparative study has been done to comprehend the effect of underlying MB on the constant composition InAlAs healing layer by analyzing the relaxation behaviour, composition and surface morphology of the grown structures. The compositional variation between the constant composition healing layers on top of graded MB has been observed in all three samples although the growth conditions have been kept same. Indium incorporation rate has been found to be dependent on underlying MB. By combining the result of atomic force microscopy, photo-luminescence and X-ray reciprocal space mapping, varying surface roughness has been proposed as the probable driving force behind different Indium incorporation rate.

  1. Comparison of different pathways in metamorphic graded buffers on GaAs substrate: Indium incorporation with surface roughness

    International Nuclear Information System (INIS)

    Kumar, Rahul; Mukhopadhyay, P.; Bag, A.; Jana, S. Kr.; Chakraborty, A.; Das, S.; Mahata, M. Kr.; Biswas, D.

    2015-01-01

    Highlights: • In(Al,Ga)As metamorphic buffers on GaAs have been grown. • Surface morphology, strain relaxation and compositional variation have been studied. • Al containing buffers shows inferior surface roughness. • Surface roughness modulates the indium incorporation rate. - Abstract: In this work, compositionally graded In(Al,Ga)As metamorphic buffers (MBs) on GaAs substrate have been grown by MBE through three different paths. A comparative study has been done to comprehend the effect of underlying MB on the constant composition InAlAs healing layer by analyzing the relaxation behaviour, composition and surface morphology of the grown structures. The compositional variation between the constant composition healing layers on top of graded MB has been observed in all three samples although the growth conditions have been kept same. Indium incorporation rate has been found to be dependent on underlying MB. By combining the result of atomic force microscopy, photo-luminescence and X-ray reciprocal space mapping, varying surface roughness has been proposed as the probable driving force behind different Indium incorporation rate

  2. Optimization and in vitro antiproliferation of Curcuma wenyujin's active extracts by ultrasonication and response surface methodology.

    Science.gov (United States)

    Wang, Xiaoqin; Jiang, Ying; Hu, Daode

    2016-01-01

    Curcuma wenyujin, a member of the genus Curcuma, has been widely prescribed for anti-cancer therapy. Multiple response surface optimization has attracted a great attention, while, the research about optimizing three or more responses employing response surface methodology (RSM) was very few. RSM and desirability function (DF) were employed to get the optimum ultrasonic extraction parameters, in which the extraction yields of curdione, furanodienone, curcumol and germacrone from C. wenyujin were maximum. The yields in the extract were accurately quantified using the validated high performance liquid chromatography method with a good precision and accuracy. The optimization results indicated that the maximum combined desirability 97.1 % was achieved at conditions as follows: liquid-solid ratio, 8 mL g(-1); ethanol concentration, 70 % and ultrasonic time, 20 min. The extraction yields gained from three verification experiments were in fine agreement with those of the model's predictions. The surface morphologies of the sonication-treated C. wenyujin were loose and rough. The extract of C. wenyujin presented obvious antiproliferative activities against RKO and HT-29 cells in vitro. Response surface methodology was successfully applied to model and optimize the ultrasonic extraction of four bioactive components from C. wenyujin for antiproliferative activitiy.Graphical abstract.

  3. Intermatrix Synthesis as a rapid, inexpensive and reproducible methodology for the in situ functionalization of nanostructured surfaces with quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Bastos-Arrieta, Julio, E-mail: julio.bastos@upc.edu [Department of Chemical Engineering, Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Muñoz, Jose, E-mail: josemaria.munoz@uab.cat [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Stenbock-Fermor, Anja, E-mail: stenbock@dwi.rwth-aachen.de [DWI – Leibniz-Institut für Interaktive Materialien, Aachen 52056 (Germany); Muñoz, Maria, E-mail: Maria.Munoz@uab.cat [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Muraviev, Dmitri N., E-mail: Dimitri.Muraviev@uab.es [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Céspedes, Francisco, E-mail: francisco.cespedes@uab.cat [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain); Tsarkova, Larisa A., E-mail: tsarkova@dwi.rwth-aachen.de [DWI – Leibniz-Institut für Interaktive Materialien, Aachen 52056 (Germany); Baeza, Mireia, E-mail: MariaDelMar.Baeza@uab.cat [Department of Chemistry, Universitat Autònoma de Barcelona, 08193 Barcelona (Spain)

    2016-04-15

    Graphical abstract: - Highlights: • Nanodiamond functionalization with CdS quantum dots. • Approach for carbon nanotube detection in water samples. • Simple functionalization of thin polymeric nanolayers with quantum dots. - Abstract: Intermatrix Synthesis (IMS) technique has proven to be a valid methodology for the in situ incorporation of quantum dots (QDs) in a wide range of nanostructured surfaces for the preparation of advanced hybrid-nanomaterials. In this sense, this communication reports the recent advances in the application of IMS for the synthesis of CdS-QDs with favourable distribution on sulfonated polyetherether ketone (SPEEK) membrane thin films (TFs), multiwall carbon nanotubes (MWCNTs) and nanodiamonds (NDs). The synthetic route takes advantage of the ion exchange functionality of the reactive surfaces for the loading of the QDs precursor and consequent QDs appearance by precipitation. The benefits of such modified nanomaterials were studied using CdS-QDs@MWCNTs hybrid-nanomaterials. CdS-QDs@MWCNTs has been used as conducting filler for the preparation of electrochemical nanocomposite sensors, which present electrocatalytic properties. Finally, the optical properties of the QDs contained on MWCNTs could allow a new procedure for the analytical detection of nanostructured carbon allotropes in water.

  4. Application of response surface methodology to tailor the surface chemistry of electrospun chitosan-poly(ethylene oxide) fibers.

    Science.gov (United States)

    Bösiger, Peter; Richard, Isabelle M T; Le Gat, Luce; Michen, Benjamin; Schubert, Mark; Rossi, René M; Fortunato, Giuseppino

    2018-04-15

    Chitosan is a promising biocompatible polymer for regenerative engineering applications, but its processing remains challenging due to limited solubility and rigid crystalline structure. This work represents the development of electrospun chitosan/poly(ethylene oxide) blend nanofibrous membranes by means of a numerical analysis in order to identify and tailor the main influencing parameters with respect to accessible surface nitrogen functionalities which are of importance for the biological activity as well as for further functionalization. Depending on the solution composition, both gradient fibers and homogenous blended fiber structures could be obtained with surface nitrogen concentrations varying between 0 and 6.4%. Response surface methodology (RSM) revealed chitosan/poly(ethylene oxide) ratio and chitosan molecular weight as the main influencing factors with respect to accessible nitrogen surface atoms and respective concentrations. The model showed good adequacy hence providing a tool to tailor the surface properties of chitosan/poly(ethylene oxide) blends by addressing the amount of accessible chitosan. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Continuous vs. pulsating flow boiling. Part 2: Statistical comparison using response surface methodology

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Meyer, Knud Erik

    2016-01-01

    Response surface methodology is used to investigate an active method for flow boiling heat transfer enhancement by means of fluid flow pulsation. The flow pulsations are introduced by a flow modulating expansion device and compared with the baseline continuous flow provided by a stepper......-motor expansion valve. Two experimental designs (data point sets) are generated using a modified Central Composite Design for each valve and their response surfaces are compared using the quadratic model. Statistical information on the significant model terms are used to clarify whether the effect of fluid flow....... The response surface comparison reveals that the flow pulsations improves the time-averaged heat transfer coefficient by as much as 10 % at the smallest cycle time compared with continuous flow. On the other hand, at highest cycle time and heat flux, the reduction may be as much as 20 % due to significant dry...

  6. Optimization of oil extraction from olive pomace using response surface methodology.

    Science.gov (United States)

    Meziane, S

    2013-08-01

    A statistical methodology, combining Plackett-Burman design with Box-Behnken design, was applied to optimize the oil extraction process from olive pomace using hexane as solvent. Plackett-Burman design was used in the first step to evaluate the effects of five independent variables on the oil extraction yield. Temperature of extraction, time of contact, solvent-to-solids ratio and moisture content of the olive pomace were identified as significant independent variables and were further optimized by using response surface methodology based on Box-Behnken design. The optimized conditions to maximize the yield were as follows: extraction temperature at 33 , contact time at 10 min, solvent-to-solids ratio at 3.5 mL/g and moisture content at 13%. The experimental value of the yield (5.98%) at these optimum conditions was found in perfect agreement with the value predicted by model (5.80%).

  7. Development of tea tree oil-loaded liposomal formulation using response surface methodology.

    Science.gov (United States)

    Ge, Yan; Ge, Mingqiao

    2015-03-23

    The aim of this study is to prepare tea tree oil liposome (TTOL) and optimize the preparation condition by single factor experiment and statistical design. TTOL was prepared using a thin-film hydration with the combination of sonication method and the preparation conditions of TTOL were optimized with response surface methodology (RSM). The optimal preparation conditions for TTOL by response surface methodology were as follows: the mass ratio of PC and Cho 5.51, TTO concentration 1.21% (v/v) and Tween 80 concentration 0.79% (v/v). The response surface analysis showed that the significant (p  0.05) lack of fit for the reduced models. Furthermore, the interaction of the mass ratio of PC/Cho and TTO concentration had a significant effect. The amounts of Tween 80 required were also reduced with RSM. Under these conditions, the experimental encapsulation efficiency of TTOL was 97.81 ± 0.33%, which was close with the predicted value. Therefore, the optimized preparation condition was very reliable. The increased entrapment efficiency would significantly improve the TTO stability and bioavailability.

  8. [Optimization of Formulation and Process of Paclitaxel PEGylated Liposomes by Box-Behnken Response Surface Methodology].

    Science.gov (United States)

    Shi, Ya-jun; Zhang, Xiao-feil; Guo, Qiu-ting

    2015-12-01

    To develop a procedure for preparing paclitaxel encapsulated PEGylated liposomes. The membrane hydration followed extraction method was used to prepare PEGylated liposomes. The process and formulation variables were optimized by "Box-Behnken Design (BBD)" of response surface methodology (RSM) with the amount of Soya phosphotidylcholine (SPC) and PEG2000-DSPE as well as the rate of SPC to drug as independent variables and entrapment efficiency as dependent variables for optimization of formulation variables while temperature, pressure and cycle times as independent variables and particle size and polydispersion index as dependent variables for process variables. The optimized liposomal formulation was characterized for particle size, Zeta potential, morphology and in vitro drug release. For entrapment efficiency, particle size, polydispersion index, Zeta potential, and in vitro drug release of PEGylated liposomes was found to be 80.3%, (97.15 ± 14.9) nm, 0.117 ± 0.019, (-30.3 ± 3.7) mV, and 37.4% in 24 h, respectively. The liposomes were found to be small, unilamellar and spherical with smooth surface as seen in transmission electron microscopy. The Box-Behnken response surface methodology facilitates the formulation and optimization of paclitaxel PEGylated liposomes.

  9. Statistical analysis of surface roughness in turning based on cutting parameters and tool vibrations with response surface methodology (RSM)

    Science.gov (United States)

    Touati, Soufiane; Mekhilef, Slimane

    2018-03-01

    In this paper, we present an experimental study to determine the effect of the cutting conditions and tool vibration on the surface roughness in finish turning of 32CrMoV12-28 steel, using carbide cutting tool YT15. For these purposes, a linear quadratic model in interaction of connecting surface roughness (Ra, Rz) with different combinations of cutting parameters such as cutting speed, feed rate, depth of cut and tool vibration, in radial and in tangential cutting force directions (Vy) and (Vz) is elaborated. In order to express the degree of interaction of cutting parameters and tool vibration, a multiple linear regression and response surface methodology are adopted. The application of this statistical technique for predicting the surface roughness shows that the feed rate is the most dominant factor followed by the cutting speed. However, the depth of the cut and tool vibrations have secondary effect. The presented models have some interest since they are used in the cutting process optimization.

  10. PENGGUNAAN RESPONSE SURFACE METHODOLOGY UNTUK OPTIMASI PROSES DEKAFEINASI MENGGUNAKAN KITOSAN DARI KULIT UDANG [The Use of Response Surface Methodology in Decaffeination Process with Chitosan

    Directory of Open Access Journals (Sweden)

    Suhardi 1

    2002-04-01

    Full Text Available The objective of the present study was to determine the optimum condition of decaffeination process with chitosan in a model system using Response Surface Methodology. A 1000ppm caffeine solution was mixed with chitosan in varried concentrations, temperatures and process times. After filtration, caffeine in the filtrate was determined. The lower caffeine in the filtrate the more effective the decaffeination process. Result of the experiment showed that among chitosan concentrations of 50, 60, 70, 80, 90, and 100 mg per 100 ml caffeine solution, the concentration of 70mg was the most effective. Among temperatures applied of 28, 40, 60, 80, 90, and 100oC, the most effective was of 90oC. And among the process times of 15, 30, 60, and 90 minutes, 15 minutes was the most effective. Result of optimatization using RSM showed that the optimum condition of decaffeination process were concentration of chitosan of 69,52mg, temperature of 89,71oC, and process time of 14,88 minutes. Under this condition the process diminished 79,56% of caffeine from the model system.

  11. Optimization of cocoa nib roasting based on sensory properties and colour using response surface methodology

    Directory of Open Access Journals (Sweden)

    D.M.H. A.H. Farah

    2012-05-01

    Full Text Available Roasting of cocoa beans is a critical stage for development of its desirable flavour, aroma and colour. Prior to roasting, cocoa bean may taste astringent, bitter, acidy, musty, unclean, nutty or even chocolate-like, depends on the bean sources and their preparations. After roasting, the bean possesses a typical intense cocoa flavour. The Maillard or non-enzymatic browning reactions is a very important process for the development of cocoa flavor, which occurs primarily during the roasting process and it has generally been agreed that the main flavor components, pyrazines formation is associated within this reaction involving amino acids and reducing sugars. The effect of cocoa nib roasting conditions on sensory properties and colour of cocoa beans were investigated in this study. Roasting conditions in terms of temperature ranged from 110 to 160OC and time ranged from 15 to 40 min were optimized by using Response Surface Methodology based on the cocoa sensory characteristics including chocolate aroma, acidity, astringency, burnt taste and overall acceptability. The analyses used 9- point hedonic scale with twelve trained panelist. The changes in colour due to the roasting condition were also monitored using chromameter. Result of this study showed that sensory quality of cocoa liquor increased with the increase in roasting time and temperature up to 160OC and up to 40 min, respectively. Based on the Response Surface Methodology, the optimised operating condition for the roaster was at temperature of 127OC and time of 25 min. The proposed roasting conditions were able to produce superior quality cocoa beans that will be very useful for cocoa manufactures.Key words : Cocoa, cocoa liquor, flavour, aroma, colour, sensory characteristic, response surface methodology.

  12. Proposal of a method for evaluating tsunami risk using response-surface methodology

    Science.gov (United States)

    Fukutani, Y.

    2017-12-01

    Information on probabilistic tsunami inundation hazards is needed to define and evaluate tsunami risk. Several methods for calculating these hazards have been proposed (e.g. Løvholt et al. (2012), Thio (2012), Fukutani et al. (2014), Goda et al. (2015)). However, these methods are inefficient, and their calculation cost is high, since they require multiple tsunami numerical simulations, therefore lacking versatility. In this study, we proposed a simpler method for tsunami risk evaluation using response-surface methodology. Kotani et al. (2016) proposed an evaluation method for the probabilistic distribution of tsunami wave-height using a response-surface methodology. We expanded their study and developed a probabilistic distribution of tsunami inundation depth. We set the depth (x1) and the slip (x2) of an earthquake fault as explanatory variables and tsunami inundation depth (y) as an object variable. Subsequently, tsunami risk could be evaluated by conducting a Monte Carlo simulation, assuming that the generation probability of an earthquake follows a Poisson distribution, the probability distribution of tsunami inundation depth follows the distribution derived from a response-surface, and the damage probability of a target follows a log normal distribution. We applied the proposed method to a wood building located on the coast of Tokyo Bay. We implemented a regression analysis based on the results of 25 tsunami numerical calculations and developed a response-surface, which was defined as y=ax1+bx2+c (a:0.2615, b:3.1763, c=-1.1802). We assumed proper probabilistic distribution for earthquake generation, inundation height, and vulnerability. Based on these probabilistic distributions, we conducted Monte Carlo simulations of 1,000,000 years. We clarified that the expected damage probability of the studied wood building is 22.5%, assuming that an earthquake occurs. The proposed method is therefore a useful and simple way to evaluate tsunami risk using a response-surface

  13. Application of Full Factorial Experimental Design and Response Surface Methodology for Chromite Beneficiation by Knelson Concentrator

    Directory of Open Access Journals (Sweden)

    Gul Akar Sen

    2016-01-01

    Full Text Available The present work is undertaken to determine the effect of operational variables, namely: feed rate, centrifugal force and fluidization water flow rate on the efficiency of Knelson concentrator for chromite ore beneficiation. A full factorial design with three factors at three levels and response surface methodology (RSM were applied for this purpose. The quadratic models were developed to predict the concentrate Cr2O3 grade and recovery as the process responses. The results suggest that all the variables affect the grade and recovery of the Cr2O3 concentrate to some degree. However, the fluidization water rate was found as the most effective parameter.

  14. Development of chitosan based edible films: process optimization using response surface methodology.

    Science.gov (United States)

    Singh, Tarun Pal; Chatli, Manish Kumar; Sahoo, Jhari

    2015-05-01

    Three-factors Box-Behnken design of response surface methodology (RSM) was used to optimize chitosan level (1.5, 2.0, 2.5 %w/v), glycerol level (0.5, 0.75, 1.0 %w/v) and drying temperature (35, 40, 45 °C) for the development of chitosan based edible films. The optimization was done on the basis of different responses viz. thickness, moisture, solubility, colour profile (L*, a*, b* value), penetrability, density, transmittance and water vapor transmission rate (WVTR). The linear effect of chitosan was significant (p fashion. Drying temperature also significantly (p industry.

  15. Isolation of Nanocrystalline Cellulose from oil palm empty fruit bunch – A response surface methodology study

    Directory of Open Access Journals (Sweden)

    Song Yee Kai

    2016-01-01

    Full Text Available The research work studied the extraction of Nano Crystalline Cellulose (NCC from oil palm empty fruit bunch (EFB, with aid of Response Surface Methodology (RSM. Particle size analysis using Malvern Zetasizer had confirmed the extracted NCC fall within the desired nano scaled range. The impact of three input parameters, namely concentration of NaOH solution during alkaline treatment, concentration of H2SO4 solution during acid hydrolysis, and duration for acid hydrolysis on NCC particle were investigated. From ANOVA study, it had suggested that the current RSM model is significant to interpret the interaction among the all three input parameters.

  16. Warpage minimization on wheel caster by optimizing process parameters using response surface methodology (RSM)

    Science.gov (United States)

    Safuan, N. S.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.

    2017-09-01

    In injection moulding process, it is important to keep the productivity increase constantly with least of waste produced such as warpage defect. Thus, this study is concerning on minimizing warpage defect on wheel caster part. Apart from eliminating product wastes, this project also giving out best optimization techniques using response surface methodology. This research studied on five parameters A-packing pressure, B-packing time, C-mold temperature, D-melting temperature and E-cooling time. The optimization showed that packing pressure is the most significant parameter. Warpage have been improved 42.64% from 0.6524 mm to 0.3742mm.

  17. Electrodeposition of Iridium Oxide by Cyclic Voltammetry: Application of Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kakooei Saeid

    2014-07-01

    Full Text Available The effects of scan rate, temperature, and number of cycles on the coating thickness of IrOX electrodeposited on a stainless steel substrate by cyclic voltammetry were investigated in a statistical system. The central composite design, combined with response surface methodology, was used to study condition of electrodeposition. All fabricated electrodes were characterized using electrochemical methods. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were performed for IrOX film characterization. Results showed that scan rate significantly affects the thickness of the electrodeposited layer. Also, the number of cycles has a greater effect than temperature on the IrOX thickness.

  18. Improvement of epoxy resin properties by incorporation of TiO2 nanoparticles surface modified with gallic acid esters

    International Nuclear Information System (INIS)

    Radoman, Tijana S.; Džunuzović, Jasna V.; Jeremić, Katarina B.; Grgur, Branimir N.; Miličević, Dejan S.; Popović, Ivanka G.; Džunuzović, Enis S.

    2014-01-01

    Highlights: • Nanocomposites of epoxy resin and TiO 2 nanoparticles surface modified with gallates. • The T g of epoxy resin was increased by incorporation of surface modified TiO 2 . • WVTR of epoxy resin decreased in the presence of surface modified TiO 2 nanoparticles. • WVTR of nanocomposites was reduced with increasing gallates hydrophobic chain length. • Modified TiO 2 nanoparticles react as oxygen scavengers, inhibiting steel corrosion. - Abstract: Epoxy resin/titanium dioxide (epoxy/TiO 2 ) nanocomposites were obtained by incorporation of TiO 2 nanoparticles surface modified with gallic acid esters in epoxy resin. TiO 2 nanoparticles were obtained by acid catalyzed hydrolysis of titanium isopropoxide and their structural characterization was performed by X-ray diffraction and transmission electron microscopy. Three gallic acid esters, having different hydrophobic part, were used for surface modification of the synthesized TiO 2 nanoparticles: propyl, hexyl and lauryl gallate. The gallate chemisorption onto surface of TiO 2 nanoparticles was confirmed by Fourier transform infrared and ultraviolet–visible spectroscopy, while the amount of surface-bonded gallates was determined using thermogravimetric analysis. The influence of the surface modified TiO 2 nanoparticles, as well as the length of hydrophobic part of the gallate used for surface modification of TiO 2 nanoparticles, on glass transition temperature, barrier, dielectric and anticorrosive properties of epoxy resin was investigated by differential scanning calorimetry, water vapor transmission test, dielectric spectroscopy, electrochemical impedance spectroscopy and polarization measurements. Incorporation of surface modified TiO 2 nanoparticles in epoxy resin caused increase of glass transition temperature and decrease of the water vapor permeability of epoxy resin. The water vapor transmission rate of epoxy/TiO 2 nanocomposites was reduced with increasing hydrophobic part chain length of

  19. Surface Signature Characterization at SPE through Ground-Proximal Methods: Methodology Change and Technical Justification

    Energy Technology Data Exchange (ETDEWEB)

    Schultz-Fellenz, Emily S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-09

    A portion of LANL’s FY15 SPE objectives includes initial ground-based or ground-proximal investigations at the SPE Phase 2 site. The area of interest is the U2ez location in Yucca Flat. This collection serves as a baseline for discrimination of surface features and acquisition of topographic signatures prior to any development or pre-shot activities associated with SPE Phase 2. Our team originally intended to perform our field investigations using previously vetted ground-based (GB) LIDAR methodologies. However, the extended proposed time frame of the GB LIDAR data collection, and associated data processing time and delivery date, were unacceptable. After technical consultation and careful literature research, LANL identified an alternative methodology to achieve our technical objectives and fully support critical model parameterization. Very-low-altitude unmanned aerial systems (UAS) photogrammetry appeared to satisfy our objectives in lieu of GB LIDAR. The SPE Phase 2 baseline collection was used as a test of this UAS photogrammetric methodology.

  20. Process optimization of rolling for zincked sheet technology using response surface methodology and genetic algorithm

    Science.gov (United States)

    Ji, Liang-Bo; Chen, Fang

    2017-07-01

    Numerical simulation and intelligent optimization technology were adopted for rolling and extrusion of zincked sheet. By response surface methodology (RSM), genetic algorithm (GA) and data processing technology, an efficient optimization of process parameters for rolling of zincked sheet was investigated. The influence trend of roller gap, rolling speed and friction factor effects on reduction rate and plate shortening rate were analyzed firstly. Then a predictive response surface model for comprehensive quality index of part was created using RSM. Simulated and predicted values were compared. Through genetic algorithm method, the optimal process parameters for the forming of rolling were solved. They were verified and the optimum process parameters of rolling were obtained. It is feasible and effective.

  1. Optimization of biosurfactant production by Bacillus brevis using response surface methodology

    Directory of Open Access Journals (Sweden)

    Foukia E. Mouafi

    2016-03-01

    Full Text Available The present study aims to evaluate and validate a statistical model for maximizing biosurfactant productivity by Bacillus brevis using response surface methodology. In this respect, twenty bacterial isolates were screened for biosurfactant production using hemolytic activity, oil spreading technique, and emulsification index (E24. The most potent biosurfactant-producing bacterium (B. brevis was used for construction of the statistical response surface model. The optimum conditions for biosurfactant production by B. brevis were: 33 °C incubation temperature at pH 8 for 10 days incubation period and 8.5 g/L glucose concentration as a sole carbon source. The produced biosurfactant (BS (73% exhibited foaming activity, thermal stability in the range 30–80 °C for 30 min., pH stability, from 4 to 9 and antimicrobial activity against (Escherichia coli. The BS gave a good potential application as an emulsifier.

  2. Optimisation of wire-cut EDM process parameter by Grey-based response surface methodology

    Science.gov (United States)

    Kumar, Amit; Soota, Tarun; Kumar, Jitendra

    2018-03-01

    Wire electric discharge machining (WEDM) is one of the advanced machining processes. Response surface methodology coupled with Grey relation analysis method has been proposed and used to optimise the machining parameters of WEDM. A face centred cubic design is used for conducting experiments on high speed steel (HSS) M2 grade workpiece material. The regression model of significant factors such as pulse-on time, pulse-off time, peak current, and wire feed is considered for optimising the responses variables material removal rate (MRR), surface roughness and Kerf width. The optimal condition of the machining parameter was obtained using the Grey relation grade. ANOVA is applied to determine significance of the input parameters for optimising the Grey relation grade.

  3. Proper Orthogonal Decomposition (POD)/Response Surface Methodology (RSM) Methodology for Low Reynolds Number Aerodynamics on Micro Aerial Vehicle (MAV)

    Science.gov (United States)

    2006-07-01

    enhanced aerodynamic method developed to obtain time-domain forces and moments for the rigid/flexible mMAV thus providing inputs for a 3DOF /Simulink...Methodology (POD/RSM) of the Unsteady Flow for given flight parameters, (5) Water/Wind Tunnel Testings for solution validation, and (6) Perform 3DOF

  4. Direct ambient noise tomography for 3-D near surface shear velocity structure: methodology and applications

    Science.gov (United States)

    Yao, H.; Fang, H.; Li, C.; Liu, Y.; Zhang, H.; van der Hilst, R. D.; Huang, Y. C.

    2014-12-01

    structures. In the future, approximate 3-D sensitivity kernels for dispersion data will be incorporated to account for finite-frequency effect of surface wave propagation. In addition, our approach provides a consistent framework for joint inversion of surface wave dispersion and body wave traveltime data for 3-D Vp and Vs structures.

  5. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Directory of Open Access Journals (Sweden)

    Thangam Chinnadurai

    2016-12-01

    Full Text Available This study focuses on investigating the effects of process parameters, namely, Peak current (Ip, Pulse on time (Ton, Pulse off time (Toff, Water pressure (Wp, Wire feed rate (Wf, Wire tension (Wt, Servo voltage (Sv and Servo feed setting (Sfs, on the Material Removal Rate (MRR and Surface Roughness (SR for Wire electrical discharge machining (Wire-EDM of nickel using Taguchi method. Response Surface Methodology (RSM is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used.

  6. Prediction of material removal rate and surface roughness for wire electrical discharge machining of nickel using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Chinnadurai, T.; Vendan, S.A.

    2016-07-01

    This study focuses on investigating the effects of process parameters, namely, Peak current (Ip), Pulse on time (Ton), Pulse off time (Toff), Water pressure (Wp), Wire feed rate (Wf), Wire tension (Wt), Servo voltage (Sv) and Servo feed setting (Sfs), on the Material Removal Rate (MRR) and Surface Roughness (SR) for Wire electrical discharge machining (Wire-EDM) of nickel using Taguchi method. Response Surface Methodology (RSM) is adopted to evolve mathematical relationships between the wire cutting process parameters and the output variables of the weld joint to determine the welding input parameters that lead to the desired optimal wire cutting quality. Besides, using response surface plots, the interaction effects of process parameters on the responses are analyzed and discussed. The statistical software Mini-tab is used to establish the design and to obtain the regression equations. The developed mathematical models are tested by analysis-of-variance (ANOVA) method to check their appropriateness and suitability. Finally, a comparison is made between measured and calculated results, which are in good agreement. This indicates that the developed models can predict the responses accurately and precisely within the limits of cutting parameter being used. (Author)

  7. Optimization of petroleum refinery effluent treatment in a UASB reactor using response surface methodology

    International Nuclear Information System (INIS)

    Rastegar, S.O.; Mousavi, S.M.; Shojaosadati, S.A.; Sheibani, S.

    2011-01-01

    Highlights: ► A UASB was successfully used for treatment of petroleum refinery effluent. ► Response surface methodology was applied to design and analysis of experiments. ► System was modeled between efficient factors include HRT, influent COD and V up . ► UASB was able to remove about 76.3% influent COD at optimum conditions. - Abstract: An upflow anaerobic sludge blanket (UASB) bioreactor was successfully used for the treatment of petroleum refinery effluent. Before optimization, chemical oxygen demand (COD) removal was 81% at a constant organic loading rate (OLR) of 0.4 kg/m 3 d and a hydraulic retention time (HRT) of 48 h. The rate of biogas production was 559 mL/h at an HRT of 40 h and an influent COD of 1000 mg/L. Response surface methodology (RSM) was applied to predict the behaviors of influent COD, upflow velocity (V up ) and HRT in the bioreactor. RSM showed that the best models for COD removal and biogas production rate were the reduced quadratic and cubic models, respectively. The optimum region, identified based on two critical responses, was an influent COD of 630 mg/L, a V up of 0.27 m/h, and an HRT of 21.4 h. This resulted in a 76.3% COD removal efficiency and a 0.25 L biogas/L feed d biogas production rate.

  8. Effect of ultrasound treatment conditions on Saccharomyces cerevisiae by response surface methodology.

    Science.gov (United States)

    Liu, Junyan; Li, Lin; Zhou, Lizhen; Li, Bing; Xu, Zhenbo

    2017-10-01

    This study aimed to investigate the effect of different ultrasound treatment conditions on the inactivation of Saccharomyces cerevisiae with the application of response surface methodology (RSM). Ultrasound treatment were applied on different concentrations of S. cerevisiae cells with different pH, temperature, ultrasound power, irradiating time, and pulse duty ratio. Cell viability was determined by plate counting method. Response surface methodology was used to analyze the correlation among various factors. Limited with low ultrasound power, lower pH value slightly improved the ultrasound treatment efficiency. Also, higher nonlethal temperature and ultrasound power, longer irradiation time, and lower pulse duty ratio facilitated the inactivation of S. cerevisiae. Cell concentration had no effect on ultrasound efficiency. Ultrasound power played the most important role in the ultrasound irradiation process according to RSM analyses. Information derived from this study may aid in the control of the sublethal injury of S. cerevisiae during ultrasound treatment in food industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Quantitative studies of rhubarb using quantitative analysis of multicomponents by single marker and response surface methodology.

    Science.gov (United States)

    Sun, Jiachen; Wu, Yueting; Dong, Shengjie; Li, Xia; Gao, Wenyuan

    2017-10-01

    In this work, we developed a novel approach to evaluate the contents of bioactive components in rhubarb. The present method was based on the quantitative analysis of multicomponents by a single-marker and response surface methodology approaches. The quantitative analysis of multicomponents by a single-marker method based on high-performance liquid chromatography coupled with photodiode array detection was developed and applied to determine the contents of 12 bioactive components in rhubarb. No significant differences were found in the results from the quantitative analysis of multicomponents by a single-marker and the external standard method. In order to maximize the extraction of 12 bioactive compounds in rhubarb, the ultrasonic-assisted extraction conditions were obtained by the response surface methodology coupled with Box-Behnken design. According to the obtained results, we showed that the optimal conditions would be as follows: proportion of ethanol/water 74.39%, solvent-to-solid ratio 24.07:1 v/w, extraction time 51.13 min, and extraction temperature 63.61°C. The analytical scheme established in this research should be a reliable, convenient, and appropriate method for quantitative determination of bioactive compounds in rhubarb. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Processing optimization of probiotic yogurt containing glucose oxidase using response surface methodology.

    Science.gov (United States)

    Cruz, A G; Faria, J A F; Walter, E H M; Andrade, R R; Cavalcanti, R N; Oliveira, C A F; Granato, D

    2010-11-01

    Exposure to oxygen may induce a lack of functionality of probiotic dairy foods because the anaerobic metabolism of probiotic bacteria compromises during storage the maintenance of their viability to provide benefits to consumer health. Glucose oxidase can constitute a potential alternative to increase the survival of probiotic bacteria in yogurt because it consumes the oxygen permeating to the inside of the pot during storage, thus making it possible to avoid the use of chemical additives. This research aimed to optimize the processing of probiotic yogurt supplemented with glucose oxidase using response surface methodology and to determine the levels of glucose and glucose oxidase that minimize the concentration of dissolved oxygen and maximize the Bifidobacterium longum count by the desirability function. Response surface methodology mathematical models adequately described the process, with adjusted determination coefficients of 83% for the oxygen and 94% for the B. longum. Linear and quadratic effects of the glucose oxidase were reported for the oxygen model, whereas for the B. longum count model an influence of the glucose oxidase at the linear level was observed followed by the quadratic influence of glucose and quadratic effect of glucose oxidase. The desirability function indicated that 62.32 ppm of glucose oxidase and 4.35 ppm of glucose was the best combination of these components for optimization of probiotic yogurt processing. An additional validation experiment was performed and results showed acceptable error between the predicted and experimental results. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. In Vitro Optimization of Enzymes Involved in Precorrin-2 Synthesis Using Response Surface Methodology.

    Science.gov (United States)

    Fang, Huan; Dong, Huina; Cai, Tao; Zheng, Ping; Li, Haixing; Zhang, Dawei; Sun, Jibin

    2016-01-01

    In order to maximize the production of biologically-derived chemicals, kinetic analyses are first necessary for predicting the role of enzyme components and coordinating enzymes in the same reaction system. Precorrin-2 is a key precursor of cobalamin and siroheme synthesis. In this study, we sought to optimize the concentrations of several molecules involved in precorrin-2 synthesis in vitro: porphobilinogen synthase (PBGS), porphobilinogen deaminase (PBGD), uroporphyrinogen III synthase (UROS), and S-adenosyl-l-methionine-dependent urogen III methyltransferase (SUMT). Response surface methodology was applied to develop a kinetic model designed to maximize precorrin-2 productivity. The optimal molar ratios of PBGS, PBGD, UROS, and SUMT were found to be approximately 1:7:7:34, respectively. Maximum precorrin-2 production was achieved at 0.1966 ± 0.0028 μM/min, agreeing with the kinetic model's predicted value of 0.1950 μM/min. The optimal concentrations of the cofactor S-adenosyl-L-methionine (SAM) and substrate 5-aminolevulinic acid (ALA) were also determined to be 200 μM and 5 mM, respectively, in a tandem-enzyme assay. By optimizing the relative concentrations of these enzymes, we were able to minimize the effects of substrate inhibition and feedback inhibition by S-adenosylhomocysteine on SUMT and thereby increase the production of precorrin-2 by approximately five-fold. These results demonstrate the effectiveness of kinetic modeling via response surface methodology for maximizing the production of biologically-derived chemicals.

  12. Optimization of ultrasonic-assisted preparation of dietary fiber from corn pericarp using response surface methodology.

    Science.gov (United States)

    Wang, Anna; Wu, Ligen; Li, Xiulin

    2013-09-01

    Corn pericarp, which is an industrial waste of corn starch production, is an important source of dietary fiber in cereals, with claimed health benefits. However, they used to be discarded or utilized as animal feed. The application of pre-ultrasound treatment is critical for achieving rapid preparation of desired components from plant materials and for preserving structural and molecular properties of these compounds. Ultrasonic-assisted preparation was used to produce dietary fiber from corn pericarp using response surface methodology. The optimal particle size of corn pericarp (mesh size 40), the ratio of liquid to solid (25 mL g⁻¹), ultrasonic power (180 W) and ultrasonic time (80 min) were determined based on response surface methodology analysis. The interaction effects of particle size of corn pericarp and ultrasonic time had a highlysignificant effect on the yield of dietary fiber, and a significant effect was shown by ultrasonic power and ultrasonic time. The maximum yield of dietary fiber was 86.84%, which agreed closely with the predicted value. Using ultrasonic-assisted preparation, it may be possible to enhance the yield of dietary fiber from corn pericarp. © 2013 Society of Chemical Industry.

  13. Modeling of Throughput in Production Lines Using Response Surface Methodology and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Federico Nuñez-Piña

    2018-01-01

    Full Text Available The problem of assigning buffers in a production line to obtain an optimum production rate is a combinatorial problem of type NP-Hard and it is known as Buffer Allocation Problem. It is of great importance for designers of production systems due to the costs involved in terms of space requirements. In this work, the relationship among the number of buffer slots, the number of work stations, and the production rate is studied. Response surface methodology and artificial neural network were used to develop predictive models to find optimal throughput values. 360 production rate values for different number of buffer slots and workstations were used to obtain a fourth-order mathematical model and four hidden layers’ artificial neural network. Both models have a good performance in predicting the throughput, although the artificial neural network model shows a better fit (R=1.0000 against the response surface methodology (R=0.9996. Moreover, the artificial neural network produces better predictions for data not utilized in the models construction. Finally, this study can be used as a guide to forecast the maximum or near maximum throughput of production lines taking into account the buffer size and the number of machines in the line.

  14. Adsorptive removal of residual catalyst from palm biodiesel: Application of response surface methodology

    Directory of Open Access Journals (Sweden)

    Mjalli Sabri Farouq

    2012-01-01

    Full Text Available In this work, the residual potassium hydroxide catalyst was removed from palm oil-based methyl esters using an adsorption technique. The produced biodiesel was initially purified through a water washing process. To produce a biodiesel with a better quality and also to meet standard specifications (EN 14214 and ASTM D6751, batch adsorption on palm shell activated carbon was used for further catalyst removal. The Central Composite Design (CCD of the Response Surface Methodology (RSM was used to study the influence of adsorbent amount, time and temperature on the adsorption of potassium species. The maximum catalyst removal was achieved at 40°C using 0.9 g activated carbon for 20 h adsorption time. The results from the Response Surface Methodology are in a good agreement with the measured values. The absolute error in prediction at the optimum condition was 3.7%, which is reasonably accurate. This study proves that adsorption post-treatment techniques can be successfully employed to improve the quality of biodiesel fuel for its effective use on diesel engines and to minimize the usage of water.

  15. Application of response surface methodology to optimize uranium biological leaching at high pulp density

    International Nuclear Information System (INIS)

    Fatemi, Faezeh; Arabieh, Masoud; Jahani, Samaneh

    2016-01-01

    The aim of the present study was to carry out uranium bioleaching via optimization of the leaching process using response surface methodology. For this purpose, the native Acidithiobacillus sp. was adapted to different pulp densities following optimization process carried out at a high pulp density. Response surface methodology based on Box-Behnken design was used to optimize the uranium bioleaching. The effects of six key parameters on the bioleaching efficiency were investigated. The process was modeled with mathematical equation, including not only first and second order terms, but also with probable interaction effects between each pair of factors.The results showed that the extraction efficiency of uranium dropped from 100% at pulp densities of 2.5, 5, 7.5 and 10% to 68% at 12.5% of pulp density. Using RSM, the optimum conditions for uranium bioleaching (12.5% (w/v)) were identified as pH = 1.96, temperature = 30.90 C, stirring speed = 158 rpm, 15.7% inoculum, FeSO 4 . 7H 2 O concentration at 13.83 g/L and (NH 4 ) 2 SO 4 concentration at 3.22 g/L which achieved 83% of uranium extraction efficiency. The results of uranium bioleaching experiment using optimized parameter showed 81% uranium extraction during 15 d. The obtained results reveal that using RSM is reliable and appropriate for optimization of parameters involved in the uranium bioleaching process.

  16. Partial oxidation of landfill leachate in supercritical water: Optimization by response surface methodology

    International Nuclear Information System (INIS)

    Gong, Yanmeng; Wang, Shuzhong; Xu, Haidong; Guo, Yang; Tang, Xingying

    2015-01-01

    Highlights: • Partial oxidation of landfill leachate in supercritical water was investigated. • The process was optimized by Box–Behnken design and response surface methodology. • GY H2 , TRE and CR could exhibit up to 14.32 mmol·gTOC −1 , 82.54% and 94.56%. • Small amounts of oxidant can decrease the generation of tar and char. - Abstract: To achieve the maximum H 2 yield (GY H2 ), TOC removal rate (TRE) and carbon recovery rate (CR), response surface methodology was applied to optimize the process parameters for supercritical water partial oxidation (SWPO) of landfill leachate in a batch reactor. Quadratic polynomial models for GY H2 , CR and TRE were established with Box–Behnken design. GY H2 , CR and TRE reached up to 14.32 mmol·gTOC −1 , 82.54% and 94.56% under optimum conditions, respectively. TRE was invariably above 91.87%. In contrast, TC removal rate (TR) only changed from 8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant carbonaceous substances in product, whereas CO 2 and H 2 were the most abundant gaseous products. As a product of nitrogen-containing organics, NH 3 has an important effect on gas composition. The carbon balance cannot be reached duo to the formation of tar and char. CR increased with the increase of temperature and oxidation coefficient

  17. Application of response surface methodology to optimize uranium biological leaching at high pulp density

    Energy Technology Data Exchange (ETDEWEB)

    Fatemi, Faezeh; Arabieh, Masoud; Jahani, Samaneh [NSTRI, Tehran (Iran, Islamic Republic of). Nuclear Fuel Cycle Research School

    2016-08-01

    The aim of the present study was to carry out uranium bioleaching via optimization of the leaching process using response surface methodology. For this purpose, the native Acidithiobacillus sp. was adapted to different pulp densities following optimization process carried out at a high pulp density. Response surface methodology based on Box-Behnken design was used to optimize the uranium bioleaching. The effects of six key parameters on the bioleaching efficiency were investigated. The process was modeled with mathematical equation, including not only first and second order terms, but also with probable interaction effects between each pair of factors.The results showed that the extraction efficiency of uranium dropped from 100% at pulp densities of 2.5, 5, 7.5 and 10% to 68% at 12.5% of pulp density. Using RSM, the optimum conditions for uranium bioleaching (12.5% (w/v)) were identified as pH = 1.96, temperature = 30.90 C, stirring speed = 158 rpm, 15.7% inoculum, FeSO{sub 4} . 7H{sub 2}O concentration at 13.83 g/L and (NH{sub 4}){sub 2}SO{sub 4} concentration at 3.22 g/L which achieved 83% of uranium extraction efficiency. The results of uranium bioleaching experiment using optimized parameter showed 81% uranium extraction during 15 d. The obtained results reveal that using RSM is reliable and appropriate for optimization of parameters involved in the uranium bioleaching process.

  18. OPTIMASI NANOENKAPSULASI ASAP CAIR TEMPURUNG KELAPA DENGAN RESPONSE SURFACE METHODOLOGY DAN KARAKTERISASI NANOKAPSUL [Optimization of Coconut Shell Liquid Smoke Nanoencapsulation using Response Surface Methodology and Nanocapsules Characterization

    Directory of Open Access Journals (Sweden)

    Dego Yusa Ali

    2014-06-01

    Full Text Available Liquid smoke is impractical and easy to deteriorate, thus needs to be protected against deterioration. Spray drying technique is widely used to encapsule bioactive compounds. This study aims to determine the optimum encapsulant ratio and spray drying process to produce nanocapsule of liqud smoke. Nanocapsules production began with the mixing of encapsulant (chitosan and maltodextrin and the liquid smoke and then agitated until dissolved. The solution of nanoparticles was heated in a water bath at 45°C for 5 minutes and homogenized using a homogenizer at 4000 rpm for 1 min. The nanoparticle solutions was spray dried at various temperatures and feed flow rates. Optimization is accomplished by using Response Surface Methodology (RSM, and the parameters to be optimized were chitosan concentration, inlet air temperature and feed flow rate of the spray dryer based on total phenolic content. Samples were analyzed for viscosity, pH, phenols staining, total phenolic, total carbonil, total acidity content, encapsulation efficiency, morphology profiles, and particle size distribution. The results showed that the nanoparticles solution of liquid smoke had a pH ranged between 2.55-2.64 total soluble solids ranged between 14-14.8°Brix and viscosity ranged between 8.7-14.9 centipoise (cP. The total phenolic content of the nanocapsules ranged from 1.38 to 2.32% with an efficiency ranged from 22.25 to 37.44%, and water content ranged from 9.56 to 10.73% (dry basis. The optimum conditions for the highest value of total phenolic content were 0.12% chitosan concentration, 140.65°C inlet air temperature and feed flow rate at 5.29 mL/min. The results suggested that nanocapsules had spherical and wrinkle shape with an average size of nanocapsules of 29.16 nm.

  19. Analysis of nonlinear vibrations and stability of rotating asymmetrical nano-shafts incorporating surface energy effects

    Science.gov (United States)

    Ghodousi, Maryam; Shahgholi, Majid; Payganeh, Gholamhassan

    2018-03-01

    The objective of the present work is to investigate the nonlinear vibrations of the rotating asymmetrical nano-shafts by considering surface effect. In order to compute the surface stress tensor, the surface elasticity theory is used. The governing nonlinear equations of motion are obtained with the aid of variational approach. Bubnov-Galerkin is a very effective method for exploiting the reduced-order model of the equations of motion. The averaging method is employed to analyze the reduced-order model of the system. For this purpose, the well-known Van der Pol transformation in the complex form and angle-action transformation are utilized. The effect of surface stress on the forward and backward speeds, steady state responses of the system, fixed points, close orbits and stability of the solutions is examined. The preliminary results of the research show that the absolute values of forward and backward whirling speeds in the presence of surface effect with positive residual surface stress are higher than those of regarding the system without surface effect and in the presence of surface effect with negative residual surface stress. In addition, it is seen that the undamped rotating asymmetrical nano-shaft, for specified value of detuning parameter, in the absence or presence of surface effect has various number of stable and unstable periodic solutions. Besides, there is different number of separatrix (homoclinic orbit type). Furthermore, bifurcations, number of solutions and their stability for damped rotating asymmetrical nano-shaft are investigated. Also, the above results have been obtained for rotating symmetrical nano-shaft.

  20. Rapid Adsorption of Heavy Metals by Fe3O4/Talc Nanocomposite and Optimization Study Using Response Surface Methodology

    Science.gov (United States)

    Kalantari, Katayoon; Ahmad, Mansor B.; Masoumi, Hamid Reza Fard; Shameli, Kamyar; Basri, Mahiran; Khandanlou, Roshanak

    2014-01-01

    Fe3O4/talc nanocomposite was used for removal of Cu(II), Ni(II), and Pb(II) ions from aqueous solutions. Experiments were designed by response surface methodology (RSM) and a quadratic model was used to predict the variables. The adsorption parameters such as adsorbent dosage, removal time, and initial ion concentration were used as the independent variables and their effects on heavy metal ion removal were investigated. Analysis of variance was incorporated to judge the adequacy of the models. Optimal conditions with initial heavy metal ion concentration of 100, 92 and 270 mg/L, 120 s of removal time and 0.12 g of adsorbent amount resulted in 72.15%, 50.23%, and 91.35% removal efficiency for Cu(II), Ni(II), and Pb(II), respectively. The predictions of the model were in good agreement with experimental results and the Fe3O4/talc nanocomposite was successfully used to remove heavy metals from aqueous solutions. PMID:25050784

  1. Optimisation of phenolic extraction from Averrhoa carambola pomace by response surface methodology and its microencapsulation by spray and freeze drying.

    Science.gov (United States)

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2015-03-15

    Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Three-dimensional reconstruction and surface extraction of lower limbs as visualization methodologies of ecchymosis.

    Science.gov (United States)

    de Lima Thomaz, Ricardo; Patrocinio, Ana Claudia; Barbosa Soares, Alcimar

    2014-01-01

    This paper presents a computational system for three-dimensional reconstruction and surface extraction of the human lower limb as a new methodology of visualizing images of multifaceted ecchymosis on the lower limbs. Through standardization of image acquisition by a mechanical system, an algorithm was developed for three-dimensional and surface reconstruction based on the extraction of depth from silhouettes. In order to validate this work, a three-dimensional model of the human lower limb was used inside a virtual environment. At this environment the mechanical procedure of image acquisition was simulated, resulting in 100 images which was later submitted to all algorithms developed. It was observed that the systems for three-dimensional reconstruction and surface extraction of the object were able to generate a new visualization method of the lesion. The results allow us to conclude that the developed systems provided adequate three-dimensional and two-dimensional visualization of the surface of the simulated model. Despite the lack of experiments with real ecchymoses, the systems developed in this work show great potential to be included in the standard methods for the visualization of ecchymoses.

  3. Incorporating stakeholders' preferences for ex ante evaluation of energy and climate policy interactions. Development of a Multi Criteria Analysis weighting methodology

    International Nuclear Information System (INIS)

    Grafakos, S.; Zevgolis, D.; Oikonomou, V.

    2008-03-01

    Evaluation of energy and climate policy interactions is a complex issue which has not been addressed systematically. Multi Criteria Decision Analysis (MCDA) evaluation processes have been applied widely to different policy and decision cases as they have the ability to cope with high complexity, by structuring and analyzing the policy problem in a transparent and systematic way. Criteria weights elicitation techniques are developed within the framework of MCDA to integrate stakeholders' preferential information in the decision making and evaluation process. There are variant methods to determine criteria weights which can be used in various ways for different policy evaluation purposes. During decision making, policy makers and relevant stakeholders implicitly or explicitly express their relative importance between the evaluation criteria by assigning weighting factors to them. More particular, climate change policy problems lack a simple, transparent and structured way to incorporate stakeholders' views and values. In order to incorporate stakeholders' weighting preferences into an ex ante evaluation of climate change and energy policy instruments interaction, an integrative constructive weighting methodology has been developed. This paper presents the main characteristics of evaluation of energy and climate policy interactions, the reasoning behind the development of the weighting tool, its main theoretical and functional characteristics and the results of its application to obtain and incorporate stakeholders' preferences on energy and climate change policy evaluation criteria. The weighting method that has been elaborated and applied to derive stakeholders' preferences for criteria weights is a combination of pair wise comparisons and ratio importance weighting methods. Initially introduces the stakeholders to the evaluation process through a warming up holistic approach for ranking the criteria and then requires them to express their ratio relative importance

  4. XPS study of PBO fiber surface modified by incorporation of hydroxyl polar groups in main chains

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Tao; Hu Dayong; Jin Junhong; Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Li Guang, E-mail: lig@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 201620 (China)

    2010-01-15

    Dihydroxy poly(p-phenylene benzobisoxazole) (DHPBO), a modified poly(p-phenylene benzoxazole) (PBO) polymer containing double hydroxyl groups in polymer chains, was synthesized by copolymerization of 4,6-diamino resorcinol dihydrochloride (DAR), purified terephthalic acid (TA) and 2,5-dihydroxyterephthalic acid (DHTA). DHPBO fibers were prepared by dry-jet wet-spinning method. The effects of hydroxyl polar groups on the surface elemental compositions of PBO fiber were investigated by X-ray photoelectron spectroscopy (XPS). The results show that the ratio of oxygen/carbon on the surface of DHPBO fibers is higher than that on the surface of PBO fibers, which indicates the content of polar groups on the surface of DHPBO fiber increase compared with PBO fiber.

  5. Modeling and Analysis of The Pressure Die Casting Using Response Surface Methodology

    International Nuclear Information System (INIS)

    Kittur, Jayant K.; Herwadkar, T. V.; Parappagoudar, M. B.

    2010-01-01

    Pressure die casting is successfully used in the manufacture of Aluminum alloys components for automobile and many other industries. Die casting is a process involving many process parameters having complex relationship with the quality of the cast product. Though various process parameters have influence on the quality of die cast component, major influence is seen by the die casting machine parameters and their proper settings. In the present work, non-linear regression models have been developed for making predictions and analyzing the effect of die casting machine parameters on the performance characteristics of die casting process. Design of Experiments (DOE) with Response Surface Methodology (RSM) has been used to analyze the effect of effect of input parameters and their interaction on the response and further used to develop nonlinear input-output relationships. Die casting machine parameters, namely, fast shot velocity, slow shot to fast shot change over point, intensification pressure and holding time have been considered as the input variables. The quality characteristics of the cast product were determined by porosity, hardness and surface rough roughness (output/responses). Design of experiments has been used to plan the experiments and analyze the impact of variables on the quality of casting. On the other-hand Response Surface Methodology (Central Composite Design) is utilized to develop non-linear input-output relationships (regression models). The developed regression models have been tested for their statistical adequacy through ANOVA test. The practical usefulness of these models has been tested with some test cases. These models can be used to make the predictions about different quality characteristics, for the known set of die casting machine parameters, without conducting the experiments.

  6. Development of performance assessment methodology for establishment of quantitative acceptance criteria of near-surface radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C. R.; Lee, E. Y.; Park, J. W.; Chang, G. M.; Park, H. Y.; Yeom, Y. S. [Korea Hydro and Nuclear Power Co., Ltd., Seoul (Korea, Republic of)

    2002-03-15

    The contents and the scope of this study are as follows : review of state-of-the-art on the establishment of waste acceptance criteria in foreign near-surface radioactive waste disposal facilities, investigation of radiological assessment methodologies and scenarios, investigation of existing models and computer codes used in performance/safety assessment, development of a performance assessment methodology(draft) to derive quantitatively radionuclide acceptance criteria of domestic near-surface disposal facility, preliminary performance/safety assessment in accordance with the developed methodology.

  7. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Directory of Open Access Journals (Sweden)

    Tam Yew

    2012-10-01

    Full Text Available Abstract Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg from Pichia pastoris expression cells were optimized using response surface methodology (RSM based on the central composite design (CCD. The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

  8. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Science.gov (United States)

    2012-01-01

    Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing. PMID:23039947

  9. Medium optimization for ε-poly-L-lysine production by Streptomyces diastatochromogenes using response surface methodology.

    Science.gov (United States)

    Guo, F; Zheng, H; Cheng, Y; Song, S; Zheng, Z; Jia, S

    2018-02-01

    Poly-ε-L-lysine is a natural homo-polyamide of L-lysine with excellent antimicrobial properties, which can be used as a novel preservative and has a wide range of applications. In this paper, the fermentation medium for ε-PL production by Streptomyces diastatochromogenes 6#-7 was optimized by Response Surface Methodology. The results of Plackett-Burman design showed that glucose, yeast extract and (NH 4 ) 2 SO 4 were the major influencing factors in ε-PL production of S. diastatochromogenes 6#-7. The optimal concentrations of glucose, yeast extract and (NH 4 ) 2 SO 4 were determined to be 60, 7·5 and 7·5 g l -1 according to Box-Behnken experiment and regression analysis, respectively. Under the optimized conditions, the ε-PL yield in shake-flask fermentation was 0·948 ± 0·030 g l -1 , which was in good agreement with the predicted value of 0·970 g l -1 . The yield was improved by 43·1% from that with the initial medium. In 5 l jar-fermenter the ε-PL yield reached 25·5 g l -1 , which was increased by 56·4% from the original medium. In addition, the fermentation time was reduced from 174 to 120 h. Medium optimization is a very practical and valuable tool for fermentation industry to improve product yield and minimize by-products as well as reduce overall manufacturing costs. The response surface methodology is not new, but it is still a very effective method in medium optimization research. This study used ε-polylysine fermentation as an example to demonstrate how the product yield can be significantly increased by medium optimization through surface response methodology. Similar approach can be used in other microbial fermentations such as in pharmaceutical, food, agricultural and energy industries. As an example, ε-polylysine is one of a few newly approved natural food-grade antimicrobials for food and beverages preservations. Yield improvement is economically beneficial to not only ε-polylysine manufacturers but also to their users and

  10. Enamel surface topography analysis for diet discrimination. A methodology to enhance and select discriminative parameters

    Science.gov (United States)

    Francisco, Arthur; Blondel, Cécile; Brunetière, Noël; Ramdarshan, Anusha; Merceron, Gildas

    2018-03-01

    Tooth wear and, more specifically, dental microwear texture is a dietary proxy that has been used for years in vertebrate paleoecology and ecology. DMTA, dental microwear texture analysis, relies on a few parameters related to the surface complexity, anisotropy and heterogeneity of the enamel facets at the micrometric scale. Working with few but physically meaningful parameters helps in comparing published results and in defining levels for classification purposes. Other dental microwear approaches are based on ISO parameters and coupled with statistical tests to find the more relevant ones. The present study roughly utilizes most of the aforementioned parameters in their more or less modified form. But more than parameters, we here propose a new approach: instead of a single parameter characterizing the whole surface, we sample the surface and thus generate 9 derived parameters in order to broaden the parameter set. The identification of the most discriminative parameters is performed with an automated procedure which is an extended and refined version of the workflows encountered in some studies. The procedure in its initial form includes the most common tools, like the ANOVA and the correlation analysis, along with the required mathematical tests. The discrimination results show that a simplified form of the procedure is able to more efficiently identify the desired number of discriminative parameters. Also highlighted are some trends like the relevance of working with both height and spatial parameters, as well as the potential benefits of dimensionless surfaces. On a set of 45 surfaces issued from 45 specimens of three modern ruminants with differences in feeding preferences (grazing, leaf-browsing and fruit-eating), it is clearly shown that the level of wear discrimination is improved with the new methodology compared to the other ones.

  11. Growth kinetics and morphology of a ballistic deposition model that incorporates surface diffusion for two species

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Cerdeira, H.A.

    1998-08-01

    We introduce a ballistic deposition model for two kinds of particles (active and inactive) in (2+1) dimensions upon introducing the surface diffusion for the inactive particles. A morphological structural transition is found as the probability of being the inactive particle increases. This transition is well defined by the change in the behavior of the surface width when it is plotted versus time and probability. The exponents α and β calculated for different values of probability show the same behavior. The presence of both types of particles issues three different processes that control the growing surface: overhanging, nonlocal growth and diffusion. It finally leads to a morphological structural transition where the universality changes away from that of Kardar-Parisi-Zhang, in (2+1) dimensions, but not into Edwards-Wilkinson's. (author)

  12. Characterization of wet granulation process parameters using response surface methodology. 1. Top-spray fluidized bed.

    Science.gov (United States)

    Lipps, D M; Sakr, A M

    1994-07-01

    Randomized full-factorial designs (3(2)) were used to investigate the effects of processing conditions in the top-spray fluidized bed (TSFB) on the granulation of acetaminophen powder (USP) using 5% polyvinylpyrrolidone (w/w) as the binder. Measured granule properties included the following: mean size and size distribution, specific surface area, bulk density, tapped density, flow rate through an orifice, angle of repose, residual moisture content, and percent overs (> 2 mm). The granules were then compressed (500, 1000, 1500 lbs) into tablets (9-mm shallow concave) using an instrumented rotary press and analyzed for both physical properties and drug-release characteristics. All experimental batches were run in triplicate to reduce the possibility of erroneous results and to increase the confidence in the resulting empirical relationships derived using response-surface methodology. Measured responses were then related to process parameters using two-factor and three-factor linear, interactions, and quadratic regression models. These models were used to generate three-dimensional response surfaces for use in the final analyses. Coefficients of determination (R2) ranging from 0.08 to 0.81 were obtained, indicating that only a portion of the variation in the data could be explained by the changes in process parameter settings during granulation and tableting. The best overall model fits were observed for mean granule size, size distribution, bulk density, tapped density, percent drug dissolution, tablet disintegration time, and tablet friability.

  13. Modeling and optimization of ammonia treatment by acidic biochar using response surface methodology

    Directory of Open Access Journals (Sweden)

    Narong Chaisongkroh

    2012-09-01

    Full Text Available Emission of ammonia (NH3 contaminated waste air to the atmosphere without treatment has affected humans andenvironment. Eliminating NH3 in waste air emitted from industries is considered an environmental requisite. In this study,optimization of NH3 adsorption time using acidic rubber wood biochar (RWBs impregnated with sulfuric acid (H2SO4 wasinvestigated. The central composite design (CCD in response surface methodology (RSM by the Design Expert softwarewas used for designing the experiments as well as the full response surface estimation. The RSM was used to evaluate theeffect of adsorption parameters in continuous mode of fixed bed column including waste air flow rate, inlet NH3 concentration in waste air stream, and H2SO4 concentration for adsorbent surface modification. Based on statistical analysis, the NH3symmetric adsorption time (at 50% NH3 removal efficiency model proved to be very highly significant (p<0.0001. The optimum conditions obtained were 300 ppmv inlet NH3 concentration, 72% H2SO4, and 2.1 l/min waste air flow rate. This resultedin 219 minutes of NH3 adsorption time as obtained from the predicted model, which fitted well with the laboratory verification result. This was supported by the high value of coefficient of determination (R2=0.9137. (NH42SO4, a nitrogen fertilizerfor planting, was the by-product from chemical adsorption between NH3 and H2SO4.

  14. Elastic-Plastic J-Integral Solutions or Surface Cracks in Tension Using an Interpolation Methodology

    Science.gov (United States)

    Allen, P. A.; Wells, D. N.

    2013-01-01

    No closed form solutions exist for the elastic-plastic J-integral for surface cracks due to the nonlinear, three-dimensional nature of the problem. Traditionally, each surface crack must be analyzed with a unique and time-consuming nonlinear finite element analysis. To overcome this shortcoming, the authors have developed and analyzed an array of 600 3D nonlinear finite element models for surface cracks in flat plates under tension loading. The solution space covers a wide range of crack shapes and depths (shape: 0.2 less than or equal to a/c less than or equal to 1, depth: 0.2 less than or equal to a/B less than or equal to 0.8) and material flow properties (elastic modulus-to-yield ratio: 100 less than or equal to E/ys less than or equal to 1,000, and hardening: 3 less than or equal to n less than or equal to 20). The authors have developed a methodology for interpolating between the goemetric and material property variables that allows the user to reliably evaluate the full elastic-plastic J-integral and force versus crack mouth opening displacement solution; thus, a solution can be obtained very rapidly by users without elastic-plastic fracture mechanics modeling experience. Complete solutions for the 600 models and 25 additional benchmark models are provided in tabular format.

  15. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Directory of Open Access Journals (Sweden)

    Jesus Corona-Gomez

    2016-07-01

    Full Text Available Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering.

  16. Effect of Nanoparticle Incorporation and Surface Coating on Mechanical Properties of Bone Scaffolds: A Brief Review

    Science.gov (United States)

    Corona-Gomez, Jesus; Chen, Xiongbiao; Yang, Qiaoqin

    2016-01-01

    Mechanical properties of a scaffold play an important role in its in vivo performance in bone tissue engineering, due to the fact that implanted scaffolds are typically subjected to stress including compression, tension, torsion, and shearing. Unfortunately, not all the materials used to fabricate scaffolds are strong enough to mimic native bones. Extensive research has been conducted in order to increase scaffold strength and mechanical performance by incorporating nanoparticles and/or coatings. An incredible improvement has been achieved; and some outstanding examples are the usage of nanodiamond, hydroxyapatite, bioactive glass particles, SiO2, MgO, and silver nanoparticles. This review paper aims to present the results, to summarize significant findings, and to give perspective for future work, which could be beneficial to future bone tissue engineering. PMID:27420104

  17. Warpage minimization: Analysis using response surface methodology (RSM) and particle swarm optimization (PSO) on thin part

    Science.gov (United States)

    Yasiin, A.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.; Sazli, M.; Yahya, Z. R.

    2017-09-01

    Injection moulding process usually used in industry manufacturing for producing variety plastic parts. The most serious issues in manufacturing is to minimize the cost of producing product without influencing their final product quality. To produce a high quality of product, it's important to control the parameters of injection moulding machine. So that, this paper presents a systematic methodology to analyse on the quality (warpage) on a top part of optical mouse using Response Surface Methodology (RSM) and Particle Swarm Optimization (PSO). Acrylonitrile Butadiene Styrene (ABS) were selected as a material that used in simulation. The variable parameters were selected based on previous researches that influence the warpage and shrinkage on the moulded part which are packing pressure, packing time, melt temperature, mould temperature and cooling time. The result shows that the warpage on the top part of optical mouse was improved 0.0043% after the optimization process. The result not affect to the change of warpage before optimise. Its conclude that using RSM is enough to optimise the parameters to get the minimum warpage of top part of optical mouse. In this study, Mould temperature was selected as the most significant factors affects the warpage, followed by packing pressure and packing time.

  18. Response surface methodology and optimization of solar powered reverse osmosis plant for brackish water desalination

    Energy Technology Data Exchange (ETDEWEB)

    Khayet, M.; Essalhi, M.; Cojocaru, C. [Univ. Complutense of Madrid, Madrid (Spain). Dept. of Applied Physics; Armenta-Deu, C. [Univ. Complutense of Madrid, Madrid (Spain). Dept. of Atomic Molecular and Nuclear Physics; Hilal, N. [Nottingham Univ., Nottingham (United Kingdom). Faculty of Engineering, Centre for Clear Water Technologies

    2010-07-01

    The costs and energy consumption associated with reverse osmosis (RO) desalination have decreased significantly in recent years due to the development of novel membranes and modules with high RO performance. In addition, adequate pretreatment processes are now used with along with energy recovery devices and renewable energy systems. Response surface methodology (RSM) was used in this study to develop a predictive model that characterized the general response of a brackish water reverse osmosis (BWRO) plant to determine the optimum operating conditions and the RO specific performance index. The RSM methodology allowed factors to be simultaneously varied between minimum and maximum values. The significance of the RSM polynomial model was determined by analysis of variance (ANOVA). The predicted and experimental responses of the BWRO plant were in good agreement. Optimization was carried out using canonical analysis and the step adjusting gradient method to ensure high quantity and quality potable water production with low energy consumption. The input variables were the feed temperature, the feed flow-rate and the feed pressure. The BWRO plant was powered with photovoltaic panels and a solar thermal collector. For a brackish water of 6 g/L salt concentration, the optimized BWRO plant guaranteed a production of 0.2 m{sup 3}/day with an energy consumption less than 1.3 kWh/m{sup 3}. 6 refs., 1 tab., 2 figs.

  19. Enhanced Production of Xylitol from Corncob by Pachysolen tannophilus Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    S. Ramesh

    2013-01-01

    Full Text Available Optimization of the culture medium and process variables for xylitol production using corncob hemicellulose hydrolysate by Pachysolen tannophilus (MTTC 1077 was performed with statistical methodology based on experimental designs. The screening of nine nutrients for their influence on xylitol production was achieved using a Plackett-Burman design. Peptone, xylose, MgSO4·7H2O, and yeast extract were selected based on their positive influence on xylitol production. The selected components were optimized with Box-Behnken design using response surface methodology (RSM. The optimum levels (g/L were peptone: 6.03, xylose: 10.62, MgSO4·7H2O: 1.39, yeast extract: 4.66. The influence of various process variables on the xylitol production was evaluated. The optimal levels of these variables were quantified by the central composite design using RSM, for establishment of a significant mathematical model with a coefficient determination of . The validation experimental was consistent with the prediction model. The optimum levels of process variables were temperature (36.56°C, pH (7.27, substrate concentration (3.55 g/L, inoculum size (3.69 mL, and agitation speed (194.44 rpm. These conditions were validated experimentally which revealed an enhanced xylitol yield of 0.80 g/g.

  20. Optimization of ultrasonic extraction of phenolic antioxidants from green tea using response surface methodology.

    Science.gov (United States)

    Lee, Lan-Sook; Lee, Namhyouck; Kim, Young Ho; Lee, Chang-Ho; Hong, Sang Pil; Jeon, Yeo-Won; Kim, Young-Eon

    2013-10-31

    Response surface methodology (RSM) has been used to optimize the extraction conditions of antioxidants with relatively low caffeine content from green tea by using ultrasonic extraction. The predicted optimal conditions for the highest antioxidant activity and minimum caffeine level were found at 19.7% ethanol, 26.4 min extraction time, and 24.0 ° C extraction temperature. In the predicted optimal conditions, the experimental values were very close to the predicted values. Moreover, the ratio of (EGCg + ECg)/EGC was identified a major factor contributing to the antioxidant activity of green tea extracts. In this study, ultrasonic extraction showed that the ethanol concentration and extraction time used for antioxidant extraction could be remarkably reduced without a decrease in antioxidant activity compared to the conventional extraction conditions.

  1. Modeling and optimizing inhibitory activities of Nelumbinis folium extract on xanthine oxidase using response surface methodology.

    Science.gov (United States)

    Sang, Mangmang; Du, Guangyan; Hao, Jia; Wang, Linlin; Liu, Erwei; Zhang, Yi; Wang, Tao; Gao, Xiumei; Han, Lifeng

    2017-05-30

    Xanthine oxidase (XOD), which could oxidize hypoxanthine to xanthine and then to uric acid, is a key enzyme in the pathogenesis of hyperuricemia and also a well-known target for the drug development to treat gout. In our study, the total alkaloids of Nelumbinis folium markedly inhibited XOD activity, with IC 50 value being 3.313μg/mL. UHPLC-Q-TOF-MS and 3D docking analysis indicated that roemerine was a potential active ingredient. A response surface methodology combined with central composite design experiment was further developed and validated for the optimization of the reaction conditions between the total alkaloids of Nelumbinis folium and XOD, which could be considered as a meaningful research for the development of XOD inhibitor rapidly and sensitively. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Response surface methodology for predicting quality characteristics of beef patties added with flaxseed and tomato paste.

    Science.gov (United States)

    Valenzuela Melendres, M; Camou, J P; Torrentera Olivera, N G; Alvarez Almora, E; González Mendoza, D; Avendaño Reyes, L; González Ríos, H

    2014-05-01

    Response surface methodology was used to study the effect of flaxseed flour (FS) and tomato paste (TP) addition, from 0 to 10% and 0 to 20% respectively, on beef patty quality characteristics. The assessed quality characteristics were color (L, a, and b), pH and texture profile analysis (TPA). Also, sensory analysis was performed for the assessment of color, juiciness, firmness, and general acceptance. FS addition reduced L and a values and decreased weight loss of cooked products (Pparameters decreased when percentages of FS and TP were increased in the formulation of beef patties. Furthermore, FS and TP addition adversely affected the sensory characteristics of the cooked product (P5.6). Thus FS and TP are ingredients that can be used in beef patty preparation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. OPTIMIZATION OF PRETREATMENT CONDITIONS OF CARROTS TO MAXIMIZE JUICE RECOVERY BY RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    H. K. SHARMA

    2006-12-01

    Full Text Available Carrot juice was expressed in a hydraulic press using a wooden set up. Carrot samples pretreated at different designed combinations, using Central Composite Rotatable Design (CCRD, Response Surface Methodology (RSM, of pH, temperature and time were expressed and juice so obtained was characterized for various physico-chemical parameters which involved yield, TSS and water content, reducing sugars, total sugars and color (absorbance. The study indicated that carrots exposed to the different pretreatment conditions resulted in increased amount of yield than that of the control. The responses were optimized by numerical method and were found to be 78.23% yield, 0.93% color (abs, 3.41% reducing sugars, 5.53% total sugars, 6.69obrix, and 90.50% water content. All the derived mathematical models for the various responses were found to be fit significantly to predict the data.

  4. Dry sliding wear investigation of Al6082/Gr metal matrix composites by response surface methodology

    Directory of Open Access Journals (Sweden)

    Pardeep Sharma

    2016-01-01

    Full Text Available The effect of graphite particles on the dry sliding wear behaviour of Al6082 alloy composites produced by conventional stir casting method has been investigated. The percentage of reinforcement was varied from 0% to 12% in a step of 3. The result showed that with the addition of graphite particles micro- and macro-hardness reduced by 11.11% and 10.44%, respectively. The tribological behaviour of composites was investigated by pin on disc apparatus. Percentage reinforcement, load, sliding speed and sliding distance were taken as the process variable. Response surface methodology has been used to plan and analyze the experiment. Results showed that sliding distance is the most influential factor and load is the factor which affects the wear least.

  5. Optimization Study in Biodiesel Production via Response Surface Methodology Using Dolomite as a Heterogeneous Catalyst

    Directory of Open Access Journals (Sweden)

    Regina C. R. Santos

    2014-01-01

    Full Text Available A carbonate mineral, dolomite, was used as a heterogeneous catalyst to produce methyl-esters from soybean oil. The samples were analyzed by XRF, TGA, XRD, TPD-CO2, and SEM. The calcination of dolomite at 800°C/1 h resulted in a highly active mixed metal oxides. In addition, the influence of the reaction variables such as the temperature, catalyst amount, and methanol/soybean oil molar ratio in methyl-ester production was optimized by the application of a central composite design in conjunction with the response surface methodology (RSM. The XRF analysis is carried out after the reuses procedure which shows that the deactivation process is mainly due to the selective calcium leaching. Overall, the calcined dolomite exhibited high catalytic activity at moderate operating conditions for biodiesel production.

  6. Bioethanol Production from Raw Juice as Intermediate of Sugar Beet Processing: A Response Surface Methodology Approach

    Directory of Open Access Journals (Sweden)

    Stevan Popov

    2010-01-01

    Full Text Available Response surface methodology (RSM was used for selecting optimal fermentation time and initial sugar mass fraction in cultivation media based on raw juice from sugar beet in order to produce ethanol. Optimal fermentation time and initial sugar mass fraction for ethanol production in batch fermentation by free Saccharomyces cerevisiae cells under anaerobic conditions at the temperature of 30 °C and agitation rate of 200 rpm were estimated to be 38 h and 12.30 % by mass, respectively. For selecting optimal conditions for industrial application, further techno-economic analysis should be performed by using the obtained mathematical representation of the process (second degree polynomial model. The overall fermentation productivity of five different types of yeast was examined and there is no significant statistical difference between them.

  7. [Optimization for supercritical CO2 extraction with response surface methodology of Prunus armeniaca oil].

    Science.gov (United States)

    Chen, Fei-Fei; Wu, Yan; Ge, Fa-Huan

    2012-03-01

    To optimize the extraction conditions of Prunus armeniaca oil by Supercritical CO2 extraction and identify its components by GC-MS. Optimized of SFE-CO extraction by response surface methodology and used GC-MS to analysis Prunus armeniaca oil compounds. Established the model of an equation for the extraction rate of Prunus armeniaca oil by supercritical CO2 extraction, and the optimal parameters for the supercritical CO2 extraction determined by the equation were: the extraction pressure was 27 MPa, temperature was 39 degrees C, the extraction rate of Prunus armeniaca oil was 44.5%. 16 main compounds of Prunus armeniaca oil extracted by supercritical CO2 were identified by GC-MS, unsaturated fatty acids were 92.6%. This process is simple, and can be used for the extraction of Prunus armeniaca oil.

  8. Cost effective production of pullulan from agri-industrial residues using response surface methodology.

    Science.gov (United States)

    Mehta, Ananya; Prasad, G S; Choudhury, Anirban Roy

    2014-03-01

    Response surface methodology was used to develop an economically feasible process for the fermentative production of pullulan using agri-industrial residues, jaggery, de-oiled jatropha seed cake (DOJSC) and corn steep liquor (CSL), as sole media components. A second order polynomial model was obtained using central composite design to understand the effects of interactions among these substrates on pullulan biosynthesis. Results indicated that, lower concentrations of CSL and DOJSC and higher concentrations of jaggery favoured pullulan production. The optimal nutrient composition (18% jaggery, 3% DOJSC and 0.97% CSL) as suggested by the model resulted in production of 66.25 g/L pullulan with a productivity of 0.92 g/Lh. Analysis of raw material cost component for pullulan production suggested that sole utilization of agri-residues may lead to development of cost effective process for pullulan production. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Response surface methodology for the optimization of alpha amylase production by serratia marcescens SB08

    International Nuclear Information System (INIS)

    Venil, C.K.; Lakshmanaperumalsamy, P.

    2008-01-01

    In this work, central composite design combining with response surface methodology was successfully employed to optimize medium composition for the production of alpha amylase by Serratia marcescens SB08 in submerged fermentation. The process parameters that influence the enzyme production were identified using Plackett- Burman design. Among the various factors screened, inoculum concentration, pH, NaCl and CaCl/sub 2/ were found to be most significant. The optimum level of pH was 5.0, inoculum concentration 3%, NaCl 0.30 g/l and CaCl/sub 2/ 0.13 g/l. The actual enzyme yield before and after optimization was 56.43 U/ml and 87.23 U/ml, respectively. Thus, it is advisable to the microbial industry sponsors to apply such profitable bioprocess to maintain high yield for mass production of alpha amylase. (author)

  10. Hardness optimization of boride diffusion layer on Astm F-75 alloy using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Arguelles O, J. L.; Corona R, M. A. [Universidad Autonoma de San Luis Potosi, Doctorado Institucional en Ingenieria y Ciencia de Materiales, San Luis Potosi 78000, SLP (Mexico); Marquez H, A.; Saldana R, A. L.; Saldana R, A. [Universidad de Guanajuato, Ingenieria Mecanica Agricola DICIVA, Irapuato, Guanajuato 36500 (Mexico); Moreno P, J., E-mail: amarquez@ugto.mx [Universidad de Guanajuato, Departamento de Minas, Metalurgia y Geologia, Ex-Hacienda San Matias s/n, Guanajuato, Guanajuato 36020 (Mexico)

    2017-11-01

    In this study, the Response Surface Methodology (Rsm) and Central Composite Design (Ccd) were used to optimize the hardness of boride diffusion layer on Astm F-75 alloy (also called Haynes alloy). A boronizing thermochemical treatment was carried out at different temperatures and for different time periods. Hardness tests were conducted. The boride diffusion layer was verified by the X-ray diffraction (XRD) analysis indicating the formation of Co B, Co{sub 2}B, Cr B and Mo{sub 2}B phases. An optimal hardness of 3139.7 Hv was obtained for the samples subjected to the boriding process for a duration of 6.86 h at 802.4 degrees Celsius. (Author)

  11. Highly Efficient Biotransformation of Polydatin to Resveratrol by Snailase Hydrolysis Using Response Surface Methodology Optimization

    Directory of Open Access Journals (Sweden)

    Lian-Xue Zhang

    2013-08-01

    Full Text Available Resveratrol (RV, a dietary antioxidant polyphenolic compound found in grapes and red wine, exerts a wide variety of pharmacological activities. However, lower content in plants compared with polydatin (PD, the glucoside of RV limits its application in the food and pharmaceutical industries. In this paper, we carried out efficient biotransformation of PD to RV with 100% conversion yield by snailase hydrolysis. Moreover, response surface methodology (RSM was used to optimize the effects of the reaction temperature, enzyme load, and reaction time on the conversion process. Validation of the RSM model was verified by the good agreement between the experimental and the predicted RV yield values. The optimum preparation conditions were as follows: temperature of 62.0 °C, enzyme load of 6.6%, and reaction time of 96 min. The proposed method may be highly applicable for the enzymatic preparation of RV for medicinal purposes.

  12. Ultrasound-assisted extraction of Mangiferin from Mango (Mangifera indica L.) leaves using response surface methodology.

    Science.gov (United States)

    Zou, Tang-Bin; Xia, En-Qin; He, Tai-Ping; Huang, Ming-Yuan; Jia, Qing; Li, Hua-Wen

    2014-01-27

    Mangiferin is a xanthone widely distributed in higher plants showing antioxidative, antiviral, anticancer, antidiabetic, immunomodulatory, hepatoprotective and analgesic effects. In the present study, an ultrasonic-assisted extraction method was developed for the effective extraction of mangiferin from mango leaves. Some parameters such as ethanol concentration, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 44% ethanol, the liquid-to-solid ratio was 38:1, and extraction for 19.2 min at 60 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of mangiferin was 58.46 ± 1.27 mg/g. The results obtained are helpful for the full utilization of mango leaves, and also indicated that ultrasonic-assisted extraction is a very useful method for the extraction of mangiferin from plant materials.

  13. Application of response surface methodology (RSM) and genetic algorithm in minimizing warpage on side arm

    Science.gov (United States)

    Raimee, N. A.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.

    2017-09-01

    The plastic injection moulding process produces large numbers of parts of high quality with great accuracy and quickly. It has widely used for production of plastic part with various shapes and geometries. Side arm is one of the product using injection moulding to manufacture it. However, there are some difficulties in adjusting the parameter variables which are mould temperature, melt temperature, packing pressure, packing time and cooling time as there are warpage happen at the tip part of side arm. Therefore, the work reported herein is about minimizing warpage on side arm product by optimizing the process parameter using Response Surface Methodology (RSM) and with additional artificial intelligence (AI) method which is Genetic Algorithm (GA).

  14. Optimization of nicotinamide and riboflavin in the biodesulfurization of dibenzothiophene using response surface methodology

    Directory of Open Access Journals (Sweden)

    Hossein Saber

    2013-01-01

    Full Text Available Introduction: Dibenzothiophene (DBT is a sulfuric compound and resistant to Hydrodesulfurization process.Rhodococcuserythropolis R1, a previously isolated bacterial strain, is capable to bioconversion of DBT to 2-hydroxybiphenyl (2-HBP.Materials and methods: The effect of nicotinamide (precursor of NAD and riboflavin (precursor of FMN on DBT biodesulfurization and growth rate by this strain was studied using Gibbs assay and turbidimeteric assay respectively. The level of cofactor precursors were optimized using response surface methodology (RSM. Results: Analyses showed that both nicotinamide and riboflavin were statistically significant and could enhance the biodesulfurization rate of DBT by induction of dsz operon. The optimum level of nicotinamide and riboflavin was obtained at 10.67 mM and 34.2 µM respectively. Discussion and conclusion: In spite of increasing in BDS, the addition of these cofactor precursors led to decreased growth rate and biomass production due to limitated effect of produced 2-HBP.

  15. Optimization of Enzymatic Process for Vanillin Extraction Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Qinghuang Wang

    2012-07-01

    Full Text Available Vanillin was extracted from vanilla beans using pretreatment with cellulase to produce enzymatic hydrolysis, and response surface methodology (RSM was applied to optimize the processing parameters of this extraction. The effects of heating time, enzyme quantity and temperature on enzymatic extraction of vanillin were evaluated. Extraction yield (mg/g was used as the response value. The results revealed that the increase in heating time and the increase in enzyme quantity (within certain ranges were associated with an enhancement of extraction yield, and that the optimal conditions for vanillin extraction were: Heating time 6 h, temperature 60 °C and enzyme quantity 33.5 mL. Calculated from the final polynomial functions, the optimal response of vanillin extraction yield was 7.62 mg/g. The predicted results for optimal reaction conditions were in good agreement with experimental values.

  16. Optimization of enzymatic process for vanillin extraction using response surface methodology.

    Science.gov (United States)

    Gu, Fenglin; Xu, Fei; Tan, Lehe; Wu, Huasong; Chu, Zhong; Wang, Qinghuang

    2012-07-25

    Vanillin was extracted from vanilla beans using pretreatment with cellulase to produce enzymatic hydrolysis, and response surface methodology (RSM) was applied to optimize the processing parameters of this extraction. The effects of heating time, enzyme quantity and temperature on enzymatic extraction of vanillin were evaluated. Extraction yield (mg/g) was used as the response value. The results revealed that the increase in heating time and the increase in enzyme quantity (within certain ranges) were associated with an enhancement of extraction yield, and that the optimal conditions for vanillin extraction were: Heating time 6 h, temperature 60 °C and enzyme quantity 33.5 mL. Calculated from the final polynomial functions, the optimal response of vanillin extraction yield was 7.62 mg/g. The predicted results for optimal reaction conditions were in good agreement with experimental values.

  17. Application of Response Surface Methodology for Optimization of Permeabilization Process of Baker’s Yeast

    Directory of Open Access Journals (Sweden)

    Trawczyńska Ilona

    2014-06-01

    Full Text Available Permeabilization was used for the purpose of transforming the cells of microorganisms into biocatalysts with an enhanced enzyme activity. Baker’s yeast cells were permeabilized with various organic solvents. A high degree of catalase activity was observed upon permeabilization with acetone, chloroform, isopropyl alcohol and ethyl acetate. Response surface methodology was used to model the effect of concentration of isopropyl alcohol, temperature and treatment time on the permeabilization of baker’s yeast cells to maximize the decomposition of H2O2. The optimum operating conditions for permeabilization were observed at 53.7% concentration of isopropyl alcohol, treatment time of 40 min and temperature of 15.6oC. A maximum value of catalase activity was found to be 6.188 U/g wet wt. and was ca. 60 times higher than the catalytic activity of yeast not treated by the permeabilization process.

  18. Hardness optimization of boride diffusion layer on Astm F-75 alloy using response surface methodology

    International Nuclear Information System (INIS)

    Arguelles O, J. L.; Corona R, M. A.; Marquez H, A.; Saldana R, A. L.; Saldana R, A.; Moreno P, J.

    2017-01-01

    In this study, the Response Surface Methodology (Rsm) and Central Composite Design (Ccd) were used to optimize the hardness of boride diffusion layer on Astm F-75 alloy (also called Haynes alloy). A boronizing thermochemical treatment was carried out at different temperatures and for different time periods. Hardness tests were conducted. The boride diffusion layer was verified by the X-ray diffraction (XRD) analysis indicating the formation of Co B, Co 2 B, Cr B and Mo 2 B phases. An optimal hardness of 3139.7 Hv was obtained for the samples subjected to the boriding process for a duration of 6.86 h at 802.4 degrees Celsius. (Author)

  19. Optimisation of conditions for the extraction of casearins from Casearia sylvestris using response surface methodology.

    Science.gov (United States)

    Bandeira, Karin F; Tininis, Aristeu G; Da Bolzani, Vanderlan S; Cavalheiro, Alberto J

    2006-01-01

    Optimal conditions for the extraction of casearins from Casearia sylvestris were determined using response surface methodology. The maceration and sonication extraction techniques were performed using a 3 x 3 x 3 full factorial design including three acidity conditions, three solvents of different polarities and three extraction times. The yields and selectivities of the extraction of casearins were significantly influenced by acidity conditions. Taking into account all variables tested, the optimal conditions for maceration extraction were estimated to involve treatment with dichloromethane saturated with ammonium hydroxide for 26 h. Similar yields and selectivities for casearins were determined for sonication extraction using the same solvent but for the much shorter time of 1 h. The best results for stabilisation of the fresh plant material were obtained using leaves that had been oven dried at 40 degrees C for 48 h.

  20. ESTABLISHING EMPIRICAL RELATION TO PREDICT TEMPERATURE DIFFERENCE OF VORTEX TUBE USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    PRABAKARAN J.

    2012-12-01

    Full Text Available Vortex tube is a device that produces cold and hot air simultaneously from the source of compressed air. In this work an attempt has been made to investigate the effect of three controllable input variables namely diameter of the orifices, diameter of the nozzles and inlet pressure over the temperature difference in the cold side as output using Response Surface Methodology (RSM. Experiments are conducted using central composite design with three factors at three levels. The influence of vital parameters and interaction among these are investigated using analysis of variance (ANOVA. The proposed mathematical model in this study has proven to fit and in line with experimental values with a 95% confidence interval. It is found that the inlet pressure and diameter of nozzle are significant factors that affect the performance of vortex tube.

  1. Optimization of the methanolysis of lard oil in the production of biodiesel with response surface methodology

    Directory of Open Access Journals (Sweden)

    Chinyere B. Ezekannagha

    2017-12-01

    Full Text Available Methanolysis of lard oil to biodiesel was optimized using central composite design (CCD of response surface methodology to delineate the effects of five levels, four factorson the yield of biodiesel. A total of 30 individual experiments were conducted and designed to study these process variables. A statistical model predicted that the highest conversion yield of lard biodiesel would be 96.2% at the following optimized reaction conditions: reaction temperature of 65 °C, catalyst amount of 1.25%, time of 40 min, methanol to oil molar ratio of 6:1 at 250 rpm. Experiments performed at the predicted optimum conditions yielded 96% which was in good agreement with the predicted value. This study shows that lard oil as a low cost feedstock is a good source of raw material for biodiesel production and a sustainable biodiesel production could be achieved with proper optimization of the process variables.

  2. A Study on Ductility of Prestressed Concrete Pier Based on Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    H. Wang

    2016-12-01

    Full Text Available The ductility of prestressed concrete pier is studied based on response surface methodology. Referring to the pervious prestressed concrete pier, based on Box-Behnken design, the ductility of 25 prestressed concrete piers is calculated by numerical method. The relationship between longitudinal reinforcement ratio, shear reinforcement ratio, prestressed tendon quantity, concrete compressive strength and ductility factor is gotten. The influence of the longitudinal reinforcement ratio, the shear reinforcement ratio, the prestressed tendon quantity and concrete compressive strength to curvature ductility is discussed. Then the ductility regression equation is deduced. The result showed that the influence of the prestressed tendon quantity to the ductility of prestressed concrete pier is significant. With the increasing of the prestressed tendon quantity, the curvature ductility curved reduces. With the increasing of shear reinforcement ratio and compressive strength of concrete, the curvature ductility increases linearly. And the influence of the longitudinal reinforcement ratio to ductility of the prestressed concrete pier is insignificant.

  3. Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Carlo Boaretti

    2015-07-01

    Full Text Available In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate and material (sulfonation degree variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers.

  4. Optimization of castor seed oil extraction process using response surface methodology

    Directory of Open Access Journals (Sweden)

    J. D. Mosquera-Artamonov

    2016-09-01

    Full Text Available This work focuses on the study of the oil extraction yield from castor seed using three different seed conditions: whole, minced and bare endosperm. Taguchi design was used to determine the contribution of the following parameters: seed condition, seed load in the extractor, temperature, and pressure. It was proved that it is necessary to introduce the whole seed and that the presence of the pericarp increases the extraction yield. The contribution of the control factors has an extraction yield limit. After determining which factors contributed to the process, these were left at their optimum levels aiming to reduce the control factors to only two. The complete analysis was done using a surface response methodology giving the best parameter for temperature and pressure that allows a better yielding mechanical extraction. The oil extraction yield can be kept up to 35% of the seed.

  5. Response Surface Methodology Study on Magnetite Nanoparticle Formation under Hydrothermal Conditions

    Directory of Open Access Journals (Sweden)

    Naoya Mizutani

    2015-05-01

    Full Text Available In a hydrothermal preparation of crystalline magnetite (Fe3O4 nanoparticles, the influence of the experimental parameters (initial molar ratio of ferrous/ferric ions, initial concentration of ferrous ions, and heating time, and their interactions, on the particle formation was studied using response surface methodology (RSM, based on a statistical design of experiments (DOE. As indices indicating particle formation and crystallization, the variation in the particle diameter and crystallite size with the synthesis conditions was examined. The crystallite size was greatly affected by both the initial ferrous/ ferric ion molar ratio and the heating time, whereas the particle diameter strongly depended on the heating time, and on the interaction between the initial ferrous/ferric ion molar ratio and the initial concentration of ferrous ions. The results from a statistical analysis suggest that the polycrystalline Fe3O4 nanoparticles form via crystal growth and/or thermal aggregation, after nucleation during hydrothermal treatment.

  6. Optimisation of steam distillation extraction oil from onion by response surface methodology and its chemical composition.

    Science.gov (United States)

    Wang, Zhao Dan; Li, Li Hua; Xia, Hui; Wang, Feng; Yang, Li Gang; Wang, Shao Kang; Sun, Gui Ju

    2018-01-01

    Oil extraction from onion was performed by steam distillation. Response surface methodology was applied to evaluate the effects of ratio of water to raw material, extraction time, zymolysis temperature and distillation times on yield of onion oil. The maximum extraction yield (1.779%) was obtained as following conditions: ratio of water to raw material was 1, extraction time was 2.5 h, zymolysis temperature was 36° and distillation time was 2.6 h. The experimental values agreed well with those predicted by regression model. The chemical composition of extracted onion oil under the optimum conditions was analysed by gas chromatography-mass spectrometry technology. The results showed that sulphur compounds, like alkanes, sulphide, alkenes, ester and alcohol, were the major components of onion oil.

  7. Power Prediction Model for Turning EN-31 Steel Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    M. Hameedullah

    2010-01-01

    Full Text Available Power consumption in turning EN-31 steel (a material that is most extensively used in automotive industry with tungstencarbide tool under different cutting conditions was experimentally investigated. The experimental runs were planned accordingto 24+8 added centre point factorial design of experiments, replicated thrice. The data collected was statisticallyanalyzed using Analysis of Variance technique and first order and second order power consumption prediction models weredeveloped by using response surface methodology (RSM. It is concluded that second-order model is more accurate than thefirst-order model and fit well with the experimental data. The model can be used in the automotive industries for decidingthe cutting parameters for minimum power consumption and hence maximum productivity

  8. OPTIMIZATION OF HIBISCUS SABDARIFFA L. (ROSELLE ANTHOCYANIN AQUEOUS-ETHANOL EXTRACTION PARAMETERS USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    ANILÚ MIRANDA-MEDINA

    2018-03-01

    Full Text Available Anthocyanins along with protocatechuic acid and quercetin have been recognized as bioactive compounds in Hibiscus sabdariffa L. aqueous extracts. Characteristic anthocyanin absorption in the visible region makes their quantification possible without the interference of the other two compounds, and also can favor its potential application as an alternative to organic-based dye sensitized solar cell, in various forms. In order to optimize measurable factors linked to the extraction of these flavonoids, an optimization was performed using a Box-Behnken experimental design and response surface methodology (RSM. Three levels of ethanol concentration, temperature and solid-solvent ratio (SSR were investigated. The optimization model showed that with 96 % EtOH, 65 °C, and 1:50 SSR, the highest anthocyanin concentration of 150 mg/100 g was obtained.

  9. OPTIMIZATION OF EXTRACELLULAR TANNASE PRODUCTION BY ASPERGILLUS NIGER VAN TIEGHEM USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    Hamada Abou-Bakr

    2013-12-01

    Full Text Available Response surface methodology (RSM was used to optimize the production of tannase by a newly isolate of Aspergillus niger Van Tieghem using rotatable central composite design (RCCD. This statistical optimization process was carried out involving four of quantitative growth parameters (variables, namely tannic acid concentration, nitrogen source concentration, initial pH of the medium and inoculum size. A mathematical model expressing the production process of tannase by submerged fermentation (SmF technique was generated statistically in the form of a second order polynomial equation. The model indicated the presence of significant linear, quadratic and interaction effects of the studied variables on tannase production by the fungal isolate. The results showed maximum tannase production (580 U/50 ml medium at 2% tannic acid, 4 g/l sodium nitrate, pH 4 and inoculum size of 5×107 spores/50 ml medium, which was also verified by experimental data.

  10. Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

    Science.gov (United States)

    Boaretti, Carlo; Roso, Martina; Lorenzetti, Alessandra; Modesti, Michele

    2015-01-01

    In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate) and material (sulfonation degree) variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers. PMID:28793427

  11. Optimization of Total Flavonoids Extraction from Coreopsis tinctoria Nutt. by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Liu, X. F.

    2014-11-01

    Full Text Available Response surface methodology (RSM was applied to predict optimum conditions for extraction of flavonoid from Coreopsis tinctoria Nutt. A central composite design (CCD was used to monitor the effect of extraction temperature, extraction time, and water-to-material ratio on yield of total flavonoids. The optimal extraction conditions were obtained as water-to-material ratio of 55 ml g−1, extraction temperature of 80 °C and extraction time of 70 minutes. Under these conditions, the average total flavonoids yield, according to the mass of raw material, was 9.0 ± 0.6 %, which corresponds to the predicted value of 8.9 %. Thus, the extraction method was applied successfully to extract total flavonoids from C. tinctoria.

  12. Ion-beam method characterization of erbium incorporation into glass surface for photonics applications

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Peřina, Vratislav; Havránek, Vladimír; Třešnáková-Nebolová, P.; Špirková, J.; Telezhniková, O.

    2004-01-01

    Roč. 566, č. 1 (2004), s. 111-114 ISSN 0039-6028 R&D Projects: GA ČR GP102/01/D069 Institutional research plan: CEZ:AV0Z1048901 Keywords : lanthanides * glass surfaces * X-ray emission Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.168, year: 2004

  13. First-principles study of Mg incorporation at wurtzite InN (0 0 0 1) and (0001-bar) surfaces

    International Nuclear Information System (INIS)

    Ding, S.F.; Qu, X.P.; Fan, G.H.

    2009-01-01

    In this article we investigate the energetics of Mg adsorption and incorporation at the InN(0 0 0 1) and InN(0001-bar) surfaces by the method of total energy plane-wave expansions with ultra-soft pseudo potential technology based on the density functional theory (DFT) in the generalized approximation (GGA). It is found that for a 1/4 monolayer (ML) coverage of the InN(0 0 0 1) surface, Mg atoms preferentially adsorb at the bridge sites and T4 sites, but they are unstable when compared with Mg incorporated in the first three layers. For a 1/4 ML coverage of the InN(0001-bar) surface, Mg atoms preferentially adsorb at the H3 sites with the formation energy of -3.49 (eV/(2x2) supercell), which is lower than that of the T4 sites, and the formation energy increases with increasing magnesium coverage. Further study shows that the formation energy for Mg atom is lower than that of In atom, which indicates that magnesium adsorption is more favorable in these conditions.

  14. In vitro study on the osteogenesis enhancement effect of BMP-2 incorporated biomimetic apatite coating on titanium surfaces.

    Science.gov (United States)

    Zhu, Xiaojing; Zhang, Hui; Zhang, Xinchun; Ning, Chengyun; Wang, Yan

    2017-09-26

    To fabricate a sustained-release delivery system of bone morphogenetic protein (BMP-2) on titanium surface, explore the effect of BMP-2 concentration on the loading/release behavior of BMP-2 and evaluate the cell compatibility of the system in vitro, pure titanium specimens were immersed into supersaturated calcium phosphate solutions (SCP) containing 4 different concentrations of BMP-2: 0, 50, 100, 200 and 400 ng/mL. Biomimetic calcium phosphate coating was formed on titanium surface and BMP-2 was incorporated into the coating through co-deposition. The release profile of BMP-2 suggested that BMP-2 were delivered sustainably up to 20 days. CCK-8 and ALP assay showed that 200 group and 400 ng/mL BMP-2 group have significant effect on promoting MC3T3-E1 cell proliferation and differentiation. The BMP-2 incorporated into the hybrid coating released in a sustained manner and significantly promoted the proliferation and differentiation of MC3T3-E1 on the titanium surface.

  15. Optimization of petroleum refinery effluent treatment in a UASB reactor using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Rastegar, S.O. [Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mousavi, S.M., E-mail: mousavi_m@modares.ac.ir [Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Shojaosadati, S.A. [Biotechnology Group, Chemical Engineering Department, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Sheibani, S. [R and T Management Department, National Iranian Oil Refining and Distribution Company, Tehran (Iran, Islamic Republic of)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer A UASB was successfully used for treatment of petroleum refinery effluent. Black-Right-Pointing-Pointer Response surface methodology was applied to design and analysis of experiments. Black-Right-Pointing-Pointer System was modeled between efficient factors include HRT, influent COD and V{sub up}. Black-Right-Pointing-Pointer UASB was able to remove about 76.3% influent COD at optimum conditions. - Abstract: An upflow anaerobic sludge blanket (UASB) bioreactor was successfully used for the treatment of petroleum refinery effluent. Before optimization, chemical oxygen demand (COD) removal was 81% at a constant organic loading rate (OLR) of 0.4 kg/m{sup 3} d and a hydraulic retention time (HRT) of 48 h. The rate of biogas production was 559 mL/h at an HRT of 40 h and an influent COD of 1000 mg/L. Response surface methodology (RSM) was applied to predict the behaviors of influent COD, upflow velocity (V{sub up}) and HRT in the bioreactor. RSM showed that the best models for COD removal and biogas production rate were the reduced quadratic and cubic models, respectively. The optimum region, identified based on two critical responses, was an influent COD of 630 mg/L, a V{sub up} of 0.27 m/h, and an HRT of 21.4 h. This resulted in a 76.3% COD removal efficiency and a 0.25 L biogas/L feed d biogas production rate.

  16. Boron-doped diamond anodic oxidation of ethidium bromide: Process optimization by response surface methodology

    International Nuclear Information System (INIS)

    Zhang Chunyong; Yang Lijiao; Rong Fei; Fu Degang; Gu Zhongze

    2012-01-01

    Highlights: ► Boron-doped diamond was used to degrade ethidium bromide. ► The process was optimized by a central composite rotatable design coupled with response surface methodology. ► Applied current is proved to be the most significant variable. ► A possible reaction sequence involving all the detected byproducts was proposed. - Abstract: The degradation of ethidium bromide (EtBr), a DNA intercalating pollutant, had been studied by anodic oxidation on boron-doped diamond (BDD) electrode under galvanostatic conditions. A central composite rotatable design coupled with response surface methodology was implemented to optimize the various operating parameters involved, among initial pH, flow rate, applied current and supporting electrolyte concentration, on the treatment efficiency; the latter was assessed in terms of color removal, COD removal, specific energy consumption and general current efficiency. Of the four parameters involved, applied current had a considerable effect on all the response factors. Optimum EtBr degradation was achieved by applying a current of 0.90 A, 9.0 mM Na 2 SO 4 , flow rate of 400 ml min −1 and pH 6.2 at 60 min of electrolysis, being reduced color by 80.2% and COD by 29.7%, with an energy consumption of 398.32 kW h (kg COD) −1 and a general current efficiency of 10.1%. Under these optimized conditions, EtBr decays followed pseudo first-order kinetics. Moreover, HPLC analysis of the BDD-treated solution allowed the detection of a number of reaction intermediates, and a possible reaction sequence involving all the detected byproducts was proposed for the electrochemical oxidation of EtBr on BDD anode.

  17. Response Surface Methodology: An Extensive Potential to Optimize in vivo Photodynamic Therapy Conditions

    International Nuclear Information System (INIS)

    Tirand, Loraine; Bastogne, Thierry; Bechet, Denise M.Sc.; Linder, Michel; Thomas, Noemie; Frochot, Celine; Guillemin, Francois; Barberi-Heyob, Muriel

    2009-01-01

    Purpose: Photodynamic therapy (PDT) is based on the interaction of a photosensitizing (PS) agent, light, and oxygen. Few new PS agents are being developed to the in vivo stage, partly because of the difficulty in finding the right treatment conditions. Response surface methodology, an empirical modeling approach based on data resulting from a set of designed experiments, was suggested as a rational solution with which to select in vivo PDT conditions by using a new peptide-conjugated PS targeting agent, neuropilin-1. Methods and Materials: A Doehlert experimental design was selected to model effects and interactions of the PS dose, fluence, and fluence rate on the growth of U87 human malignant glioma cell xenografts in nude mice, using a fixed drug-light interval. All experimental results were computed by Nemrod-W software and Matlab. Results: Intrinsic diameter growth rate, a tumor growth parameter independent of the initial volume of the tumor, was selected as the response variable and was compared to tumor growth delay and relative tumor volumes. With only 13 experimental conditions tested, an optimal PDT condition was selected (PS agent dose, 2.80 mg/kg; fluence, 120 J/cm 2 ; fluence rate, 85 mW/cm 2 ). Treatment of glioma-bearing mice with the peptide-conjugated PS agent, followed by the optimized PDT condition showed a statistically significant improvement in delaying tumor growth compared with animals who received the PDT with the nonconjugated PS agent. Conclusions: Response surface methodology appears to be a useful experimental approach for rapid testing of different treatment conditions and determination of optimal values of PDT factors for any PS agent.

  18. Partial oxidation of landfill leachate in supercritical water: Optimization by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yanmeng; Wang, Shuzhong; Xu, Haidong; Guo, Yang; Tang, Xingying

    2015-09-15

    Highlights: • Partial oxidation of landfill leachate in supercritical water was investigated. • The process was optimized by Box–Behnken design and response surface methodology. • GY{sub H2}, TRE and CR could exhibit up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56%. • Small amounts of oxidant can decrease the generation of tar and char. - Abstract: To achieve the maximum H{sub 2} yield (GY{sub H2}), TOC removal rate (TRE) and carbon recovery rate (CR), response surface methodology was applied to optimize the process parameters for supercritical water partial oxidation (SWPO) of landfill leachate in a batch reactor. Quadratic polynomial models for GY{sub H2}, CR and TRE were established with Box–Behnken design. GY{sub H2}, CR and TRE reached up to 14.32 mmol·gTOC{sup −1}, 82.54% and 94.56% under optimum conditions, respectively. TRE was invariably above 91.87%. In contrast, TC removal rate (TR) only changed from 8.76% to 32.98%. Furthermore, carbonate and bicarbonate were the most abundant carbonaceous substances in product, whereas CO{sub 2} and H{sub 2} were the most abundant gaseous products. As a product of nitrogen-containing organics, NH{sub 3} has an important effect on gas composition. The carbon balance cannot be reached duo to the formation of tar and char. CR increased with the increase of temperature and oxidation coefficient.

  19. Optimization of low-cost biosurfactant production from agricultural residues through response surface methodology.

    Science.gov (United States)

    Ebadipour, N; Lotfabad, T Bagheri; Yaghmaei, S; RoostaAzad, R

    2016-01-01

    Biosurfactants are surface-active compounds capable of reducing surface tension and interfacial tension. Biosurfactants are produced by various microorganisms. They are promising replacements for chemical surfactants because of biodegradability, nontoxicity, and their ability to be produced from renewable sources. However, a major obstacle in producing biosurfactants at the industrial level is the lack of cost-effectiveness. In the present study, by using corn steep liquor (CSL) as a low-cost agricultural waste, not only is the production cost reduced but a higher production yield is also achieved. Moreover, a response surface methodology (RSM) approach through the Box-Behnken method was applied to optimize the biosurfactant production level. The results found that biosurfactant production was improved around 2.3 times at optimum condition when the CSL was at a concentration of 1.88 mL/L and yeast extract was reduced to 25 times less than what was used in a basic soybean oil medium (SOM). The predicted and experimental values of responses were in reasonable agreement with each other (Pred-R(2) = 0.86 and adj-R(2) = 0.94). Optimization led to a drop in raw material price per unit of biosurfactant from $47 to $12/kg. Moreover, the biosurfactant product at a concentration of 84 mg/L could lower the surface tension of twice-distilled water from 72 mN/m to less than 28 mN/m and emulsify an equal volume of kerosene by an emulsification index of (E24) 68% in a two-phase mixture. These capabilities made these biosurfactants applicable in microbial enhanced oil recovery (MEOR), hydrocarbon remediation, and all other petroleum industry surfactant applications.

  20. Effects of calcium ion incorporation on osteoblast gene expression in MC3T3-E1 cells cultured on microstructured titanium surfaces.

    Science.gov (United States)

    Park, Jin-Woo; Suh, Jo-Young; Chung, Hyun-Ju

    2008-07-01

    The surface characteristics of a calcium ion (Ca)-incorporated titanium (Ti) surface, produced by hydrothermal treatment using an alkaline Ca-containing solution, and its effects on osteoblastic differentiation were investigated. MC3T3-E1 pre-osteoblastic cells were cultured on machined or grit-blasted Ti surfaces with and without Ca incorporation. The MTT assay was used to determine cell proliferation, and real-time PCR was used for quantitative analysis of osteoblastic gene expression. Hydrothermal treatment with a Ca-containing solution produced a crystalline CaTiO(3) nanostructure of approximately 100 nm in dimension, preserving original micron-scaled surface topographies and microroughness caused by machining, blasting, or blasting and etching treatments. After immersion in Hank's balanced salt solution, considerable apatite formation was observed on all surfaces of the Ca-incorporated samples. Significantly more cell proliferation was found on Ca-incorporated Ti surfaces than on untreated Ti surfaces (p < 0.001). Quantitative real-time PCR analysis showed notably higher alkaline phosphatase, osteopontin, and osteocalcin mRNA levels in cells grown on Ca-incorporated blasted surfaces than on other surfaces at an early time point. Thus, Ca incorporation may have a beneficial effect on osseointegration of microstructured Ti implants by accelerating osteoblast proliferation and differentiation during the early healing phase following implantation. (c) 2007 Wiley Periodicals, Inc.

  1. RBS, PIXE and NDP study of erbium incorporation into glass surface for photonics applications

    Czech Academy of Sciences Publication Activity Database

    Macková, Anna; Havránek, Vladimír; Vacík, Jiří; Salavcová, Linda; Spirková-Hradilová, J.

    2006-01-01

    Roč. 249, 1-2 (2006), s. 856-858 ISSN 0168-583X R&D Projects: GA AV ČR(CZ) KJB100480601; GA ČR GA106/03/0505; GA ČR GA106/05/0706 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z20670512 Keywords : surface analyses * photonics glass * Er diffusion Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.946, year: 2006

  2. Optimization of enzymatic clarification of green asparagus juice using response surface methodology.

    Science.gov (United States)

    Chen, Xuehong; Xu, Feng; Qin, Weidong; Ma, Lihua; Zheng, Yonghua

    2012-06-01

    Enzymatic clarification conditions for green asparagus juice were optimized by using response surface methodology (RSM). The asparagus juice was treated with pectinase at different temperatures (35 °C-45 °C), pH values (4.00-5.00), and enzyme concentrations (0.6-1.8 v/v%). The effects of enzymatic treatment on juice clarity and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity were investigated by employing a 3-factor central composite design coupled with RSM. According to response surface analysis, the optimal enzymatic treatment condition was pectinase concentration of 1.45%, incubation temperature of 40.56 °C and pH of 4.43. The clarity, juice yield, and soluble solid contents in asparagus juice were significantly increased by enzymatic treatment at the optimal conditions. DPPH radical-scavenging capacity was maintained at the level close to that of raw asparagus juice. These results indicated that enzymatic treatment could be a useful technique for producing green asparagus juice with high clarity and high-antioxidant activity. Treatment with 1.45% pectinase at 40.56 ° C, pH 4.43, significantly increased the clarity and yield of asparagus juice. In addition, enzymatic treatment maintained antioxidant activity. Thus, enzymatic treatment has the potential for industrial asparagus juice clarification. © 2012 Institute of Food Technologists®

  3. Response Surface Methodology: An Emphatic Tool for Optimized Biodiesel Production Using Rice Bran and Sunflower Oils

    Directory of Open Access Journals (Sweden)

    Farooq Ahmad

    2012-09-01

    Full Text Available The current study describes the emphatic use of response surface methodology for the optimized biodiesel production using chemical and enzymatic transesterification of rice bran and sunflower oils. Optimal biodiesel yields were determined to be 65.3 ± 2.0%, 73.4 ± 3.5%, 96.5 ± 1.6%, 89.3 ± 2.0% and 41.7 ± 3.9% for rice bran oil and 65.6 ± 1.2%, 82.1 ± 1.7%, 92.5 ± 2.8%, 72.6 ± 1.6% and 50.4 ± 2.5% for sunflower oil via the transesterification catalyzed by NaOH, KOH and NaOCH3,NOVOZYME-435 and A.n. Lipase, respectively. Based upon analysis of variance (ANOVA and Response Surface plots significant impact of reaction parameters under study was ascertained. FTIR spectroscopic and HPLC methods were employed for monitoring the transesterification reaction progress while GC-MS analysis was performed to evaluate the compositional analysis of biodiesel. The fuel properties of both the rice bran and sunflower oil based biodiesel were shown to be technically compatible with the ASTM D6751 and EN 14214 standards. The monitoring of exhaust emission of synthesized biodiesels and their blends revealed a marked reduction in carbon monoxide (CO and particulate matter (PM levels, whereas an irregular trend was observed for NOx emissions.

  4. Physical stability assessment and sensory optimization of a dairy-free emulsion using response surface methodology.

    Science.gov (United States)

    Granato, Daniel; de Castro, I Alves; Ellendersen, L Souza Neves; Masson, M Lucia

    2010-04-01

    Desserts made with soy cream, which are oil-in-water emulsions, are widely consumed by lactose-intolerant individuals in Brazil. In this regard, this study aimed at using response surface methodology (RSM) to optimize the sensory attributes of a soy-based emulsion over a range of pink guava juice (GJ: 22% to 32%) and soy protein (SP: 1% to 3%). WHC and backscattering were analyzed after 72 h of storage at 7 degrees C. Furthermore, a rating test was performed to determine the degree of liking of color, taste, creaminess, appearance, and overall acceptability. The data showed that the samples were stable against gravity and storage. The models developed by RSM adequately described the creaminess, taste, and appearance of the emulsions. The response surface of the desirability function was used successfully in the optimization of the sensory properties of dairy-free emulsions, suggesting that a product with 30.35% GJ and 3% SP was the best combination of these components. The optimized sample presented suitable sensory properties, in addition to being a source of dietary fiber, iron, copper, and ascorbic acid.

  5. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology

    Science.gov (United States)

    Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

    2015-02-01

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g).

  6. Adsorption of uranium by amidoximated chitosan-grafted polyacrylonitrile, using response surface methodology.

    Science.gov (United States)

    Xu, Chao; Wang, Jingjing; Yang, Tilong; Chen, Xia; Liu, Xunyue; Ding, Xingcheng

    2015-05-05

    The amidoximated chitosan-grafted polyacrylonitrile (CTS-g-PAO) was prepared for the adsorption of uranium from water. The effects of pH, concentration of uranium and the solid-liquid ratio on the adsorption of uranium by CTS-g-PAO were optimized using Doehlert design of response surface methodology (RSM). The adsorption capacity and removal efficiency achieved 312.06 mg/g and 86.02%, respectively. The adsorption process attained equilibrium only in 120 min. More than 80% of the absorbed uranium could be desorbed by 0.1 mol/l HCl or EDTA-Na, and CTS-g-PAO could be reused at least 3 times. The CTS-g-PAO and U(VI) ions formed a chelate complex due to FTIR spectral analysis. The surface morphology of CTS-g-PAO was also investigated by SEM. The adsorption process was better described by Langmuir isotherm and pseudo second order kinetic model. Results obtained indicated that CTS-g-PAO was very promising in adsorption of uranium from water. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Optimization of ultrasound-assisted extraction of glycyrrhizic acid from licorice using response surface methodology.

    Science.gov (United States)

    Jang, Seol; Lee, A Yeong; Lee, A Reum; Choi, Goya; Kim, Ho Kyoung

    2017-12-01

    The present study optimized ultrasound-assisted extraction conditions to maximize extraction yields of glycyrrhizic acid from licorice. The optimal extraction temperature (X 1 ), extraction time (X 2 ), and methanol concentration (X 3 ) were identified using response surface methodology (RSM). A central composite design (CCD) was used for experimental design and analysis of the results to obtain the optimal processing parameters. Statistical analyses revealed that three variables and the quadratic of X 1 , X 2 , and X 3 had significant effects on the yields and were followed by significant interaction effects between the variables of X 2 and X 3 ( p response surface plot and contour plots derived from the mathematical models were applied to determine the optimal conditions. The optimum ultrasound-assisted extraction conditions were as follows: extraction temperature, 69 °C; extraction time, 34 min; and methanol concentration, 57%. Under these conditions, the experimental yield of glycyrrhizic acid was 3.414%, which agreed closely with the predicted value (3.406%). The experimental values agreed with those predicted by RSM models, thus indicating the suitability of the model employed and the success of RSM in optimizing the extraction conditions.

  8. Methodology of licensing for field applications of Weld Inlay and Ultrasonic Nanocrystal Surface Modification

    International Nuclear Information System (INIS)

    Cho, Hong Seok; Jung, Kwang Woon; Park, Ik Keun; Pyun, Young Sik

    2015-01-01

    There are many attempts to relieve or change high tensile residual stress to compressive residual stress for a mitigation of PWSCC. LSP(Laser Shot Peening) and WJP(Water Jet Peening) have been applied in several NPPs of Japan and technical and topical reports under Materials Reliability Program of EPRI(Electric Power Research Institute ) USA have been developed. Weld Inlay technology and UNSM(Ultrasonic Nanocrystal Surface Modification) technology using ultrasonic vibration energy as the method for a mitigation of tensile residual stress generated after Weld Inlay have been developing in Korea. So in this study, the methodology of licensing for field application of these technologies is suggested. The results of residual stress measured before and after UNSM for Weld Inlay specimens using UNSM equipment of domestic source technology holdings to obtain an equivalent effect, which has the simplification of equipment and the flexibility of field application in comparison with LSP and WJP, indicated to obtain a mitigation effect of residual stress until 0.5 mm of surface depth. In order to accomplish field application of Weld Inlay that the Code Case was already developed, the approval of a regulation agency through the preparation of TR or RR based on ASME Code Case N-766, N-803 is necessary

  9. Methodology of licensing for field applications of Weld Inlay and Ultrasonic Nanocrystal Surface Modification

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hong Seok; Jung, Kwang Woon [KEPCO KPS, Naju (Korea, Republic of); Park, Ik Keun [Seoul National Univ, Seoul (Korea, Republic of); Pyun, Young Sik [Sun Moon University, Asan (Korea, Republic of)

    2015-10-15

    There are many attempts to relieve or change high tensile residual stress to compressive residual stress for a mitigation of PWSCC. LSP(Laser Shot Peening) and WJP(Water Jet Peening) have been applied in several NPPs of Japan and technical and topical reports under Materials Reliability Program of EPRI(Electric Power Research Institute ) USA have been developed. Weld Inlay technology and UNSM(Ultrasonic Nanocrystal Surface Modification) technology using ultrasonic vibration energy as the method for a mitigation of tensile residual stress generated after Weld Inlay have been developing in Korea. So in this study, the methodology of licensing for field application of these technologies is suggested. The results of residual stress measured before and after UNSM for Weld Inlay specimens using UNSM equipment of domestic source technology holdings to obtain an equivalent effect, which has the simplification of equipment and the flexibility of field application in comparison with LSP and WJP, indicated to obtain a mitigation effect of residual stress until 0.5 mm of surface depth. In order to accomplish field application of Weld Inlay that the Code Case was already developed, the approval of a regulation agency through the preparation of TR or RR based on ASME Code Case N-766, N-803 is necessary.

  10. Study of Syngas Conversion to Light Olefins by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Hossein Atashi

    2013-01-01

    Full Text Available The effect of adding MgO to a precipitated iron-cobalt-manganese based Fischer-Tropsch synthesis (FTS catalyst was investigated via response surface methodology. The catalytic performance of the catalysts was examined in a fixed bed microreactor at a total pressure of 1–7 bar, temperature of 280–380°C, MgO content of 5–25% and using a syngas having a H2 to CO ratio equal to 2.The dependence of the activity and product distribution on MgO content, temperature, and pressure was successfully correlated via full quadratic second-order polynomial equations. The statistical analysis and response surface demonstrations indicated that MgO significantly influences the CO conversion and chain growth probability as well as ethane, propane, propylene, butylene selectivity, and alkene/alkane ratio. A strong interaction between variables was also evidenced in some cases. The decreasing effect of pressure on alkene to alkane ratio is investigated through olefin readsorption effects and CO hydrogenation kinetics. Finally, a multiobjective optimization procedure was employed to calculate the best amount of MgO content in different reactor conditions.

  11. Optimization of Sugar Replacement with Date Syrup in Prebiotic Chocolate Milk Using Response Surface Methodology

    Science.gov (United States)

    2017-01-01

    Chocolate milk is one of the most commonly used non-fermentative dairy products, which, due to high level of sucrose, could lead to diabetes and tooth decay among children. Therefore, it is important to replace sucrose with other types of sweeteners, especially, natural ones. In this research, response surface methodology (RSM) was used to optimize the ingredients formulation of prebiotic chocolate milk, date syrup as sweetener (4-10%w/w), inulin as prebiotic texturizer (0-0.5%w/w) and carrageenan as thickening agent (0-0.04%w/w) in the formulation of chocolate milk. The fitted models to predict the variables of selected responses such as pH, viscosity, total solid, sedimentation and overall acceptability of chocolate milk showed a high coefficient of determination. The independent effect of carrageenan was the most effective parameter which led to pH and sedimentation decrease but increased viscosity. Moreover, in most treatments, date syrup and inulin variables had significant effects which had a mutual impact. Optimization of the variables, based on the responses surface 3D plots showed that the sample containing 0.48% (w/w) of inulin, 0.04% (w/w) of carrageenan, and 10% of date syrup was selected as the optimum condition. PMID:28747831

  12. Amoxicillin degradation from contaminated water by solar photocatalysis using response surface methodology (RSM).

    Science.gov (United States)

    Moosavi, Fatemeh Sadat; Tavakoli, Touraj

    2016-11-01

    In this study, the solar photocatalytic process in a pilot plant with compound parabolic collectors (CPCs) was performed for amoxicillin (AMX) degradation, an antibiotic widely used in the world. The response surface methodology (RSM) based on Box-Behnken statistical experiment design was used to optimize independent variables, namely TiO 2 dosage, antibiotic initial concentration, and initial pH. The results showed that AMX degradation efficiency affected by positive or negative effect of variables and their interactions. The TiO 2 dosage, pH, and interaction between AMX initial concentration and TiO 2 dosage exhibited a synergistic effect, while the linear and quadratic term of AMX initial concentration and pH showed antagonistic effect in the process response. Response surface and contour plots were used to perform process optimization. The optimum conditions found in this regard were TiO 2 dosage = 1.5 g/L, AMX initial concentration = 17 mg/L, and pH = 9.5 for AMX degradation under 240 min solar irradiation. The photocatalytic degradation of AMX after 34.95 kJ UV /L accumulated UV energy per liter of solution was 84.12 % at the solar plant.

  13. Antiproliferative activity of Curcuma phaeocaulis Valeton extract using ultrasonic assistance and response surface methodology.

    Science.gov (United States)

    Wang, Xiaoqin; Jiang, Ying; Hu, Daode

    2017-01-02

    The objective of the study was to optimize the ultrasonic-assisted extraction of curdione, furanodienone, curcumol, and germacrone from Curcuma phaeocaulis Valeton (Val.) and investigate the antiproliferative activity of the extract. Under the suitable high-performance liquid chromatography condition, the calibration curves for these four tested compounds showed high levels of linearity and the recoveries of these four compounds were between 97.9 and 104.3%. Response surface methodology (RSM) combining central composite design and desirability function (DF) was used to define optimal extraction parameters. The results of RSM and DF revealed that the optimum conditions were obtained as 8 mL g -1 for liquid-solid ratio, 70% ethanol concentration, and 20 min of ultrasonic time. It was found that the surface structures of the sonicated herbal materials were fluffy and irregular. The C. phaeocaulis Val. extract significantly inhibited the proliferation of RKO and HT-29 cells in vitro. The results reveal that the RSM can be effectively used for optimizing the ultrasonic-assisted extraction of bioactive components from C. phaeocaulis Val. for antiproliferative activity.

  14. Optimization of ultrasound-assisted extraction of polyphenolic compounds from coriander seeds using response surface methodology

    Directory of Open Access Journals (Sweden)

    Zeković Zoran P.

    2016-01-01

    Full Text Available Coriandrum sativum L. (coriander seeds (CS were used for preparation of extracts with high content of biologically active compounds. In order to optimize ultrasoundassisted extraction process, three levels and three variables of Box-Behnken experimental design (BBD in combination with response surface methodology (RSM were applied, yielding maximized total phenolics (TP and flavonoids (TF content and antioxidant activity (IC50 and EC50 values. Independent variables were temperature (40-80oC, extraction time (40-80 min and ultrasonic power (96-216 W. Experimental results were fitted to a second-order polynomial model with multiple regression, while the analysis of variance (ANOVA was employed to assess the model fitness and determine optimal conditions for TP (79.60oC, 49.20 min, 96.69 W, TF (79.40oC, 43.60 min, 216.00 W, IC50 (80.00oC, 60.40 min, 216.00 W and EC50 (78.40oC, 68.60 min, 214.80 W. On the basis of the obtained mathematical models, three-dimensional surface plots were generated. The predicted values for TP, TF, IC50 and EC50 were: 382.68 mg GAE/100 g CS, 216 mg CE/100 g CS, 0.03764 mg/mL and 0.1425 mg/mL, respectively. [Projekat Ministarstva nauke Republike Srbije, br. TR31013

  15. Biosynthesis of ergot alkaloids from penicillium commune using response surface methodology (RSM)

    International Nuclear Information System (INIS)

    Shahid, M. G.; Cheema, T. A.; Baig, S.; Nadeem, M.; Nelofar, R.

    2017-01-01

    The present study employed the response surface methodology (RSM), a statistical technique, for the identification, screening and optimization of fermentation factors to produce ergot alkaloids under laboratory conditions by Penicillium commune. The static surface culture fermentation technique helped to enhance the production of ergot alkaloids. In the first step Plackett-Burman design (PBD) was used to evaluate the effect of ten factors, including nine ingredients of fermentation medium and one process parameter. It was found that sucrose, yeast extract and FeSO/sub 4/.7H/sub 2/O played the pivotal role in enhancing the yield of ergot alkaloids. In the second step, the effect of concentration levels of sucrose, yeast extract and FeSO/sub 4/.7H/sub 2/O was further optimized using Box-Behnken design (BBD) under the same fermentation conditions. The optimized concentrations of sucrose, yeast extract and FeSO/sub 4/.7H/sub 2/O were 41%, 39% and 0.11% respectively, which significantly enhanced the yield of ergot alkaloids. (author)

  16. Spectrophotometric determination of anionic surfactants: optimization by response surface methodology and application to Algiers bay wastewater.

    Science.gov (United States)

    Sini, Karima; Idouhar, Madjid; Ahmia, Aida-Cherifa; Ferradj, Abdelhak; Tazerouti, Ammal

    2017-11-23

    A simple analytical method for quantitative determination of an anionic surfactant in aqueous solutions without liquid-liquid extraction is described. The method is based on the formation of a green-colored ion associate between sodium dodecylbenzenesulfonate (SDBS) and cationic dye, Brilliant Green (BG) in acidic medium. Spectral changes of the dye by addition of SDBS are studied by visible spectrophotometry at maximum wave length of 627 nm. The interactions and micellar properties of SDBS and cationic dye are also investigated using surface tension method. The pH, the molar ratio ([BG]/[SDBS]), and the shaking time of the solutions are considered as the main parameters which affect the formation of the ion pair. Determination of AS in distilled water gives a significant detection limit up to 3 × 10 -6  M. The response surface methodology (RSM) is applied to study the absorbance. A Box-Behnken is a model designed to the establishment of responses given by parameters with great probability. This model is set up by using the three main parameters at three levels. Analysis of variance shows that only two parameters affect the absorbance of the ion pair. The statistical results obtained are interesting and give us real possibility to reach optimum conditions for the formation of the ion pair. As the proposed method is free from interferences from major constituents of water, it has been successfully applied to the determination of anionic surfactant contents in wastewaters samples collected from Algiers bay.

  17. Investigation of structural transformations in surface layer of phosphate glasses incorporating radiactive wastes

    International Nuclear Information System (INIS)

    Aloj, A.S.; Kolycheva, T.I.; Trofimenko, A.V.; Shashukov, E.A.

    1985-01-01

    The objective of the paper was to clarify possibilities of detection of structural transformations initial stages on the surface of phosphate glasses using the method of infrared reflection spectroscopy. Phase composition of crystalline compounds formed in surface glass layer is determined by the method of X-ray diffraction. All experiments were performed using sodium alumophosphate glass comprising the model mixture of fission product of the following compostion (mass%): Na 2 O-22.0, Al 2 O 3 -14.0, P 2 O 5 -50.0, Fe 2 O 3 -3.5, Cs 2 O-3.5, SrO-3.0, Ln 2 O 3 -4.0, where Ln 2 O 3 is a mixture of cerium, lanthanum and europium oxides. Sample preparation were carried out by molten glass deposition on platinum forms 15mm in diameter and 4mm thick. Glasses were treated within the 600-400deg.C temperature range. Fixing of processes accompanied by structural transformations was accomplished the method of rapid cooling. It has been shown that phase transformations, taking place in investigated phosphate glasses under the action of heat, result in deterioration of chemical properties. Analysis of IR spectra has revealed that emergence of structural transformations in surface layer of investigated glasses results in variation of a ratio of 1060 and 1140cm - 1 reflection band intensities. Experimental dependences of the time of beginning of variation of 1060 and 1140cm - 1 bands relative intensity on temperature are presented. Insemilogarithmic coordinates this dependence has a straight line form within the 600-400 deg C temperature range and is desc ribed by the following formular: lg r=-7.41+5.70x10 3 x1/T, where r is the time of process beginning, h. Extrapolation of established to the region of low temperature is shown. Competence of such extrapolation may be confirmed in the course of further experiments

  18. Clarification of Pharmaceutical Wastewater with Moringa Oleifera: Optimization Through Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Iva Rustanti Eri

    2018-05-01

    Full Text Available Herbal pharmaceutical industrial wastewater contains a high amount of suspended solids and alkaline (pH > 8; therefore it requires approprite coagulant and flocculant compounds for its wastewater treatment. The most widely used flocculant is a synthetic that has certain problems such as non-biodegradability and releases of toxic residual monomers. The use of eco-friendly flocculants as alternative materials for conventional flocculant in water and wastewater treatments is increasing. Numerous factors influence the performance of coagulation-flocculation process, such as coagulant dosage, flocculant dosage, initial potential of hydrogen (pH and velocity gradient of coagulation-flocculation. The main aim of this research is to evaluate the capability and effectiveness of Moringa oleifera extract for removal of suspended solid in herbal pharmaceutical industry. A coagulation-flocculation test was done by performing jar test at various speeds, according to the variation of the conducted treatment research. In this study, response surface methodology (RSM approach was used to optimize the concentration of coagulant dosage, flocculant dosage and flocculation velocity gradient (G, and the results were measured as maximum percentage of suspended solid removal. The wastewater used in this research originally came from the inlet of herbal pharmaceutical industry wastewater treatment plant, which was collected over 3 days. The wastewater has a total suspended solids of more than 1250 mg/L, and was alkaline (pH 9-10. The moringa extract was made from the extraction of a fat free moringa powder with a salt solution in a certain ratio. The percentage removal of suspended solid was 93.42-99.54%. The final results of the analysis of response surface showed that the variables of flocculant dosage and the flocculation velocity gradient (G have a huge impact on the amount of suspended solid removal, compared with the coagulant dosage. The model generated from the

  19. Incorporating and Compensating Cerebrospinal Fluid in Surface-Based Forward Models of Magneto- and Electroencephalography.

    Directory of Open Access Journals (Sweden)

    Matti Stenroos

    Full Text Available MEG/EEG source imaging is usually done using a three-shell (3-S or a simpler head model. Such models omit cerebrospinal fluid (CSF that strongly affects the volume currents. We present a four-compartment (4-C boundary-element (BEM model that incorporates the CSF and is computationally efficient and straightforward to build using freely available software. We propose a way for compensating the omission of CSF by decreasing the skull conductivity of the 3-S model, and study the robustness of the 4-C and 3-S models to errors in skull conductivity. We generated dense boundary meshes using MRI datasets and automated SimNIBS pipeline. Then, we built a dense 4-C reference model using Galerkin BEM, and 4-C and 3-S test models using coarser meshes and both Galerkin and collocation BEMs. We compared field topographies of cortical sources, applying various skull conductivities and fitting conductivities that minimized the relative error in 4-C and 3-S models. When the CSF was left out from the EEG model, our compensated, unbiased approach improved the accuracy of the 3-S model considerably compared to the conventional approach, where CSF is neglected without any compensation (mean relative error 40%. The error due to the omission of CSF was of the same order in MEG and compensated EEG. EEG has, however, large overall error due to uncertain skull conductivity. Our results show that a realistic 4-C MEG/EEG model can be implemented using standard tools and basic BEM, without excessive workload or computational burden. If the CSF is omitted, compensated skull conductivity should be used in EEG.

  20. Improvement of surface wetting properties of poly(p-phenylene benzoxazole) by incorporation of ionic groups

    Energy Technology Data Exchange (ETDEWEB)

    Luo Kaiqing [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Jin Junhong [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Yang Shenglin [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China); Li Guang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China)]. E-mail: lig@dhu.edu.cn; Jiang Jianming [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai 200051 (China)

    2006-07-25

    Modified poly(p-phenylene benzoxazole), SPBO, containing ionic sulfonate groups was synthesized by polycondensation of the corresponding monomers in polyphosphoric acid. SPBO fiber was spun via a dry-jet wet-spinning technique. The wetting property of poly(p-phenylene benzoxazole) (PBO) fiber and SPBO fiber were measured by contact angle analysis, and the interfacial shear strength (IFSS) between fibers and epoxy was determined by microbond pull-out testing. The contact angles of water and ethanol on SPBO fiber surface get smaller, and the wetting process becomes faster. The surface free energy of SPBO fiber increases to 38.9 mJ m{sup -2}, which is 9.6% higher than that of PBO fiber. Furthermore the ionic introducing leads to a 23% increase in IFSS from 8.2 MPa for PBO/epoxy to 10.1 MPa for SPBO/epoxy. It could be expected that the failure mode may change from fiber/matrix interface adhesive failure to partly cohesive failure mode.

  1. Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys.

    Science.gov (United States)

    Shen, Xiao-Ting; Zhang, Yan-Zhen; Xiao, Fang; Zhu, Jing; Zheng, Xiao-Dong

    2017-07-01

    The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles (AgNPs) were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction: AgNO 3 +NaBH 4 → Ag+1/2H 2 +1/2B 2 H 6 +NaNO 3 . A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells (MC3T3-E1) from mice and mesenchymal stem cells (BMSC) from rats. The antibacterial properties of dental alloys incorporating three different concentrations (10, 4, and 2 μmol/L) of AgNPs were tested on Staphylococcus aureus (SA) and Streptococcus mutans (MS). High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs (the control groups). The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorporation of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.

  2. Durable Self-Cleaning Coatings for Architectural Surfaces by Incorporation of TiO₂ Nano-Particles into Hydroxyapatite Films.

    Science.gov (United States)

    Sassoni, Enrico; D'Amen, Eros; Roveri, Norberto; Scherer, George W; Franzoni, Elisa

    2018-01-23

    To prevent soiling of marble exposed outdoors, the use of TiO₂ nano-particles has been proposed in the literature by two main routes, both raising durability issues: (i) direct application to marble surface, with the risk of particle leaching by rainfall; (ii) particle incorporation into inorganic or organic coatings, with the risk of organic coating degradation catalyzed by TiO₂ photoactivity. Here, we investigated the combination of nano-TiO₂ and hydroxyapatite (HAP), previously developed for marble protection against dissolution in rain and mechanical consolidation. HAP-TiO₂ combination was investigated by two routes: (i) sequential application of HAP followed by nano-TiO₂ ("H+T"); (ii) simultaneous application by introducing nano-TiO₂ into the phosphate solution used to form HAP ("HT"). The self-cleaning ability was evaluated before and after prolonged exposure to simulated rain. "H+T" and "HT" coatings exhibited much better resistance to nano-TiO₂ leaching by rain, compared to TiO₂ alone. In "H+T" samples, TiO₂ nano-particles adhere better to HAP (having flower-like morphology and high specific surface area) than to marble. In "HT" samples, thanks to chemical bonds between nano-TiO₂ and HAP, the particles are firmly incorporated in the HAP coating, which protects them from leaching by rain, without diminishing their photoactivity and without being degraded by them.

  3. Extraction of curcuminoids by using ethyl lactate and its optimisation by response surface methodology.

    Science.gov (United States)

    D'Archivio, Angelo Antonio; Maggi, Maria Anna; Ruggieri, Fabrizio

    2018-02-05

    Response surface methodology (RSM) was applied to optimise the extraction of curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) from turmeric using ethyl lactate (EL), ethanol and water under mild conditions (magnetic stirring at room temperature). An augmented simplex-centroid mixture design was used to monitor the dependence of the extraction efficiency from the proportions of the three solvents in the extraction medium. HPLC was used to establish the content of curcuminoids in turmeric and in the extracts. Surface plots for the extracted amount of each curcuminoid covering the whole composition domain were generated by interpolation of the experimental data with quadratic canonical polynomial models. The response surfaces of the three curcuminoids are qualitatively similar and the maximum extraction efficiency was obtained with water-EL 30:70v/v that ensured the almost quantitative recovery of the three compounds from turmeric. While degradation of the three curcuminoids in water at moderate alkaline pH is relatively fast (half-times are between 0.23 and 8.5h at pH=8.6), their stability is noticeably greater in EL (half-times are within 21-69days). Addition of EL to water is also able to inhibit the alkaline hydrolysis of curcumin and its derivatives, their half-times in the water-EL 30:70v/v, being within 40-70h at pH=8.6. The above evidences suggest that EL is a promising solvent for the extraction of curcuminods from turmeric and a suitable medium for vehiculation of these compounds into drugs or foods. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Neural Network and Response Surface Methodology for Rocket Engine Component Optimization

    Science.gov (United States)

    Vaidyanathan, Rajkumar; Papita, Nilay; Shyy, Wei; Tucker, P. Kevin; Griffin, Lisa W.; Haftka, Raphael; Fitz-Coy, Norman; McConnaughey, Helen (Technical Monitor)

    2000-01-01

    The goal of this work is to compare the performance of response surface methodology (RSM) and two types of neural networks (NN) to aid preliminary design of two rocket engine components. A data set of 45 training points and 20 test points obtained from a semi-empirical model based on three design variables is used for a shear coaxial injector element. Data for supersonic turbine design is based on six design variables, 76 training, data and 18 test data obtained from simplified aerodynamic analysis. Several RS and NN are first constructed using the training data. The test data are then employed to select the best RS or NN. Quadratic and cubic response surfaces. radial basis neural network (RBNN) and back-propagation neural network (BPNN) are compared. Two-layered RBNN are generated using two different training algorithms, namely solverbe and solverb. A two layered BPNN is generated with Tan-Sigmoid transfer function. Various issues related to the training of the neural networks are addressed including number of neurons, error goals, spread constants and the accuracy of different models in representing the design space. A search for the optimum design is carried out using a standard gradient-based optimization algorithm over the response surfaces represented by the polynomials and trained neural networks. Usually a cubic polynominal performs better than the quadratic polynomial but exceptions have been noticed. Among the NN choices, the RBNN designed using solverb yields more consistent performance for both engine components considered. The training of RBNN is easier as it requires linear regression. This coupled with the consistency in performance promise the possibility of it being used as an optimization strategy for engineering design problems.

  5. Optimization and evaluation of chelerythrine nanoparticles composed of magnetic multiwalled carbon nanotubes by response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yong [School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541014 (China); Yuan, Yulin [Department of Clinical Laboratory, the People' s Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021 (China); Zhou, Zhide; Liang, Jintao; Chen, Zhencheng [School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541014 (China); Li, Guiyin, E-mail: liguiyin01@163.com [School of Life and Environmental Sciences, Guilin University of Electronic Technology, Guilin, Guangxi 541014 (China)

    2014-02-15

    In this study, a new chelerythrine nanomaterial targeted drug delivery system (Fe{sub 3}O{sub 4}/MWNTs-CHE) was designed with chelerythrine (CHE) as model of antitumor drug and magnetic multiwalled carbon nanotubes (Fe{sub 3}O{sub 4}/MWNTs) nanocomposites as drug carrier. The process and formulation variables of Fe{sub 3}O{sub 4}/MWNTs-CHE were optimized using response surface methodology (RSM) with a three-level, three-factor Box–Behnken design (BBD). Mathematical equations and response surface plots were used to relate the dependent and independent variables. The experimental results were fitted into second-order response surface model. When Fe{sub 3}O{sub 4}/MWNTs:CHE ratio was 20.6:1, CHE concentration was 172.0 μg/mL, temperature was 34.5 °C, the drug loading content and entrapment efficiency were 3.04 ± 0.17% and 63.68 ± 2.36%, respectively. The optimized Fe{sub 3}O{sub 4}/MWNTs-CHE nanoparticles were characterized by scanning electron microscopy (SEM), Zeta potential, in vitro drug release and MTT assays. The in vitro CHE drug release behavior from Fe{sub 3}O{sub 4}/MWNTs-CHE displayed a biphasic drug release pattern and followed Korsmeyer–Peppas model with Fickian diffusion mechanism for drug release. The results from MTT assays suggested that the Fe{sub 3}O{sub 4}/MWNTs-CHE could effectively inhibit the proliferation of human hepatoma cells (HepG2), which displayed time or concentration-dependent manner. All these preliminary studies were expected to provide a theoretical basis and offer new methods for preparation efficient magnetic targeted drug delivery systems.

  6. Optimization of VCSELs incorporating monolithic subwavelength high-refractive-index contrast surface grating mirrors

    Science.gov (United States)

    Gebski, Marcin; Marciniak, Magdalena; Dems, Maciej; Czyszanowski, Tomasz; Lott, James A.

    2017-02-01

    We present results of computer simulations of vertical cavity surface emitting lasers (VCSELs) using novel, highreflectivity monolithic high refractive-index contrast grating (MHCG) mirrors and their more advanced version, partially covered by a thin metal layer - metallic MHCG (mMHCG) mirrors. The first experimental realization of this new class of mirrors is presented and discussed. We show that the metal layer does not deteriorate the high reflectivity of an mMHCG mirror, but in contrary, is a crucial element which allows high reflectivity and additionally opens a way for a more efficient electrical pumping of a VCSEL. Comparison of results of thermal-electrical-carrier-gain self-consistent simulations of both MHCG- and mMHCG-based VCSELs is presented and discussed. It is shown that using mHCG mirror as a top mirror of a VCSEL improves electrical characteristics and greatly decreases the differential resistance of the device.

  7. Global Cr-isotope distributions in surface seawater and incorporation of Cr isotopes into carbonate shells

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie; Frei, Robert; Vögelin, Andrea Regula

    In this study we present the Cr-isotope composition of surface seawater from several locations worldwide. In addition to the samples from the oceans (Atlantic Ocean, Pacific Ocean, Southern Ocean and Artic Ocean) we analysed water samples from areas with a more limited water exchange (Mediterranean...... Sea, Baltic Sea, Øresund and Kattegat). The long residence time of Cr (7,000 to 40,000 years) [1,2,3] relative to the ocean mixing time (1,000 to 2,000 years) [4] could lead to the expectation that the Cr concentration and Cr-isotope distribution are homogeneous in the oceans. However, our seawater...... observed a negative correlation between the Cr-isotope composition and the Cr concentration. Exceptions are samples from the Baltic Sea/Øresund, which are isotopically light despite low Cr concentrations (~0.1-0.2 ppb). In addition to the seawater data, we measured Cr isotopes in modern biologically...

  8. Characterize Cold Bituminous Emulsion Mixtures Incorporated Ordinary Portland Cement Filler for Local Surface Layer

    Directory of Open Access Journals (Sweden)

    Mustafa Amoori Kadhim

    2018-02-01

    Full Text Available Cold Bituminous Emulsion Mixtures have many environmental, logistical, and economic advantages over conventional Hot Mix Asphalt. Nevertheless, their inferior performance and high water sensitivity at early life attract little attentions. Moreover, it is impossible to apply CBEM as a structural surface layer if left without treatment or enhancement. The main aim of this study is to enhance the properties of CBEM for the hope of using it as a structural layer. Thus, a trial has been made to improve CBEM mechanical and durability properties by replacing the Ordinary Portland Cement by the Conventional Mineral Filler with 3 percentages; namely, 0, 50%, and 100%. CBEM mixtures mechanical properties were evaluated in term of Marshall Stability and Flow, Indirect Tensile Strength, and Wheel Track Test. While Moisture damage was evaluated in terms of Retained Marshall Stability. Test results showed that the addition of 100%OPC filler can improve CBEM mechanical and durability properties efficiently. In terms of mechanical properties results, CBEM comprised 100%OPC, can be used as a structural Surface layer based on local Iraqi specifications limits, where mixture enhanced about 1.9, 1.78, 9,4.85, and 2.6  times in term of MS, MF, rutting deformation resistance, resistance to tensile cracking, and moisture damage resistance, respectively as compared to untreated CBEM. Also, CBEM-100%OPC mix seemed comparable (and sometime superior to HMA, e.g., resistance to rutting of CBEM is about 6.2 times higher than that of HMA. It’s worth to say that OPC upgrades CBEM to a significant level that enables it to use as a structural layer in terms of the mechanical and the durability properties.

  9. Microwave-Assisted Extraction of Cannabinoids in Hemp Nut Using Response Surface Methodology: Optimization and Comparative Study

    Directory of Open Access Journals (Sweden)

    Chih-Wei Chang

    2017-11-01

    Full Text Available Hemp nut is commonly incorporated into several food preparations; however, most countries set regulations for hemp products according to their cannabinoid content. In this study, we have developed an efficient microwave-assisted extraction (MAE method for cannabinoids (i.e., Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol in hemp nut. Optimization of the MAE procedure was conducted through single factor experiments and response surface methodology (RSM. A comparative study was also conducted to determine the differences in the extraction yields and morphology of hemp nut between MAE and reference extraction methods, namely heat reflux extraction (HRE, Soxhlet extraction (SE, supercritical fluid extraction (SFE, and ultrasound-assisted extraction (UAE. Among the independent variables in RSM, the temperature was the most significant parameter. The optimal conditions of MAE were as follows: extraction solvent of methanol, microwave power of 375 W, temperature of 109 °C, and extraction time of 30 min. Compared with reference extraction methods, MAE achieved the highest extraction yields of total cannabinoids in hemp nut (6.09 μg/g for MAE; 4.15 μg/g for HRE; 5.81 μg/g for SE; 3.61 μg/g for SFE; 3.73 μg/g for UAE with the least solvent consumption and shortest time. Morphological observations showed that substantial cell rupturing occurred in the microstructure of hemp nut after MAE, indicating enhanced dissolution of the target compounds during the extraction process. The MAE method is thus a rapid, economic, and environmentally friendly extraction method that is both effective and practical for industrial applications.

  10. Microwave-Assisted Extraction of Cannabinoids in Hemp Nut Using Response Surface Methodology: Optimization and Comparative Study.

    Science.gov (United States)

    Chang, Chih-Wei; Yen, Ching-Chi; Wu, Ming-Tsang; Hsu, Mei-Chich; Wu, Yu-Tse

    2017-11-03

    Hemp nut is commonly incorporated into several food preparations; however, most countries set regulations for hemp products according to their cannabinoid content. In this study, we have developed an efficient microwave-assisted extraction (MAE) method for cannabinoids (i.e., Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol) in hemp nut. Optimization of the MAE procedure was conducted through single factor experiments and response surface methodology (RSM). A comparative study was also conducted to determine the differences in the extraction yields and morphology of hemp nut between MAE and reference extraction methods, namely heat reflux extraction (HRE), Soxhlet extraction (SE), supercritical fluid extraction (SFE), and ultrasound-assisted extraction (UAE). Among the independent variables in RSM, the temperature was the most significant parameter. The optimal conditions of MAE were as follows: extraction solvent of methanol, microwave power of 375 W, temperature of 109 °C, and extraction time of 30 min. Compared with reference extraction methods, MAE achieved the highest extraction yields of total cannabinoids in hemp nut (6.09 μg/g for MAE; 4.15 μg/g for HRE; 5.81 μg/g for SE; 3.61 μg/g for SFE; 3.73 μg/g for UAE) with the least solvent consumption and shortest time. Morphological observations showed that substantial cell rupturing occurred in the microstructure of hemp nut after MAE, indicating enhanced dissolution of the target compounds during the extraction process. The MAE method is thus a rapid, economic, and environmentally friendly extraction method that is both effective and practical for industrial applications.

  11. Exploring codon optimization and response surface methodology to express biologically active transmembrane RANKL in E. coli.

    Science.gov (United States)

    Maharjan, Sushila; Singh, Bijay; Bok, Jin-Duck; Kim, Jeong-In; Jiang, Tao; Cho, Chong-Su; Kang, Sang-Kee; Choi, Yun-Jaie

    2014-01-01

    Receptor activator of nuclear factor (NF)-κB ligand (RANKL), a master cytokine that drives osteoclast differentiation, activation and survival, exists in both transmembrane and extracellular forms. To date, studies on physiological role of RANKL have been mainly carried out with extracellular RANKL probably due to difficulties in achieving high level expression of functional transmembrane RANKL (mRANKL). In the present study, we took advantage of codon optimization and response surface methodology to optimize the soluble expression of mRANKL in E. coli. We optimized the codon usage of mRANKL sequence to a preferred set of codons for E. coli changing its codon adaptation index from 0.64 to 0.76, tending to increase its expression level in E. coli. Further, we utilized central composite design to predict the optimum combination of variables (cell density before induction, lactose concentration, post-induction temperature and post-induction time) for the expression of mRANKL. Finally, we investigated the effects of various experimental parameters using response surface methodology. The best combination of response variables was 0.6 OD600, 7.5 mM lactose, 26°C post-induction temperature and 5 h post-induction time that produced 52.4 mg/L of fusion mRANKL. Prior to functional analysis of the protein, we purified mRANKL to homogeneity and confirmed the existence of trimeric form of mRANKL by native gel electrophoresis and gel filtration chromatography. Further, the biological activity of mRANKL to induce osteoclast formation on RAW264.7 cells was confirmed by tartrate resistant acid phosphatase assay and quantitative real-time polymerase chain reaction assays. Importantly, a new finding from this study was that the biological activity of mRANKL is higher than its extracellular counterpart. To the best of our knowledge, this is the first time to report heterologous expression of mRANKL in soluble form and to perform a comparative study of functional properties of both

  12. Exploring codon optimization and response surface methodology to express biologically active transmembrane RANKL in E. coli.

    Directory of Open Access Journals (Sweden)

    Sushila Maharjan

    Full Text Available Receptor activator of nuclear factor (NF-κB ligand (RANKL, a master cytokine that drives osteoclast differentiation, activation and survival, exists in both transmembrane and extracellular forms. To date, studies on physiological role of RANKL have been mainly carried out with extracellular RANKL probably due to difficulties in achieving high level expression of functional transmembrane RANKL (mRANKL. In the present study, we took advantage of codon optimization and response surface methodology to optimize the soluble expression of mRANKL in E. coli. We optimized the codon usage of mRANKL sequence to a preferred set of codons for E. coli changing its codon adaptation index from 0.64 to 0.76, tending to increase its expression level in E. coli. Further, we utilized central composite design to predict the optimum combination of variables (cell density before induction, lactose concentration, post-induction temperature and post-induction time for the expression of mRANKL. Finally, we investigated the effects of various experimental parameters using response surface methodology. The best combination of response variables was 0.6 OD600, 7.5 mM lactose, 26°C post-induction temperature and 5 h post-induction time that produced 52.4 mg/L of fusion mRANKL. Prior to functional analysis of the protein, we purified mRANKL to homogeneity and confirmed the existence of trimeric form of mRANKL by native gel electrophoresis and gel filtration chromatography. Further, the biological activity of mRANKL to induce osteoclast formation on RAW264.7 cells was confirmed by tartrate resistant acid phosphatase assay and quantitative real-time polymerase chain reaction assays. Importantly, a new finding from this study was that the biological activity of mRANKL is higher than its extracellular counterpart. To the best of our knowledge, this is the first time to report heterologous expression of mRANKL in soluble form and to perform a comparative study of functional

  13. Application of Response Surface Methodology in Extraction of Bioactive Component from Palm Leaves (Elaeis guineensis

    Directory of Open Access Journals (Sweden)

    Nur Afiqah Arham

    2013-10-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 The hydroxyl groups of the polyphenols are capable to act as reducing agent for reduction reaction. The effect of drying temperature, extraction temperature and extraction duration were evaluated using central composite design which consists of 20 experimental runs. Response surface methodology (RSM was used to estimate the optimum parameters in extracting polyphenols from the palm leaves. The correspondence analysis of the results yielded a quadratic model which can be used to find optimum conditions of extraction process. The optimum extraction condition of drying temperature, extraction temperature and extraction duration are 70°C, at 70°C of 10 minutes, respectively. Total polyphenols were determined by application of the Folin-Ciocalteu micro method and the extract was found contain of 8 mg GAE/g dry palm leaves at optimum conditions. Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Doi: 10.12777/ijse.5.2.95-100 [How to cite this article: Arham, N.A., Mohamad, N.A.N., Jai, J., Krishnan, J., Noorsuhana Mohd Yusof, N.M. (2013. Application of Response Surface Methodology in Extraction of Bioactive Component from Palm Leaves (Elaeis guineensis. International Journal of Science and

  14. Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

    KAUST Repository

    Leonard, J. T.

    2015-07-06

    © 2015 AIP Publishing LLC. We report on our recent progress in improving the performance of nonpolar III-nitride vertical-cavity surface-emitting lasers (VCSELs) by using an Al ion implanted aperture and employing a multi-layer electron-beam evaporated ITO intracavity contact. The use of an ion implanted aperture improves the lateral confinement over SiNx apertures by enabling a planar ITO design, while the multi-layer ITO contact minimizes scattering losses due to its epitaxially smooth morphology. The reported VCSEL has 10 QWs, with a 3nm quantum well width, 1nm barriers, a 5nm electron-blocking layer, and a 6.95- λ total cavity thickness. These advances yield a single longitudinal mode 406nm nonpolar VCSEL with a low threshold current density (∼16kA/cm2), a peak output power of ∼12μW, and a 100% polarization ratio. The lasing in the current aperture is observed to be spatially non-uniform, which is likely a result of filamentation caused by non-uniform current spreading, lateral optical confinement, contact resistance, and absorption loss.

  15. Mass Sensitivity Optimization of a Surface Acoustic Wave Sensor Incorporating a Resonator Configuration

    Directory of Open Access Journals (Sweden)

    Wenchang Hao

    2016-04-01

    Full Text Available The effect of the sensitive area of the two-port resonator configuration on the mass sensitivity of a Rayleigh surface acoustic wave (R-SAW sensor was investigated theoretically, and verified in experiments. A theoretical model utilizing a 3-dimensional finite element method (FEM approach was established to extract the coupling-of-modes (COM parameters in the absence and presence of mass loading covering the electrode structures. The COM model was used to simulate the frequency response of an R-SAW resonator by a P-matrix cascading technique. Cascading the P-matrixes of unloaded areas with mass loaded areas, the sensitivity for different sensitive areas was obtained by analyzing the frequency shift. The performance of the sensitivity analysis was confirmed by the measured responses from the silicon dioxide (SiO2 deposited on different sensitive areas of R-SAW resonators. It is shown that the mass sensitivity varies strongly for different sensitive areas, and the optimal sensitive area lies towards the center of the device.

  16. ASAM - The international programme on application of safety assessment methodologies for near surface radioactive waste disposal facilities

    International Nuclear Information System (INIS)

    Batandjieva, B.

    2002-01-01

    The IAEA has launched a new Co-ordinated Research Project (CRP) on Application of Safety Assessment Methodologies for Near Surface Waste Disposal Facilities (ASAM). The CRP will focus on the practical application of the safety assessment methodology, developed under the ISAM programme, for different purposes, such as developing design concepts, licensing, upgrading existing repositories, reassessment of operating disposal facilities. The overall aim of the programme is to assist safety assessors, regulators and other specialists involved in the development and review of safety assessment for near surface disposal facilities in order to achieve transparent, traceable and defendable evaluation of safety of these facilities. (author)

  17. Biosynthesized iron oxide nanoparticles used for optimized removal of cadmium with response surface methodology.

    Science.gov (United States)

    Lin, Jiajiang; Su, Binglin; Sun, Mengqiang; Chen, Bo; Chen, Zuliang

    2018-06-15

    To effectively reuse adsorbent in removal of Cd (II), magnetic modification was considered as an alternative. In this study, iron oxide nanoparticles (IONPs) synthesized from the extract of Excoecaria cochinchinensis Lour leaves were modified by low-temperature calcination, and used to remove Cd (II). Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and magnetic properties analysis confirmed the successful synthesis of nanoscale magnetic FeOC composite. Response surface methodology (RSM) served to optimize the adsorption of Cd (II) by IONPs based on Box-Behnken design (BBD). According to the quadratic model, the effect of each factor on the removal of Cd (II) by IONPs was: pH > dosage > ionic strength > temperature. In percentage terms, 98.50% of Cd (II) (10 mg L -1 ) was removed when the pH, absorbent dosage, temperature and ionic strength conditions were 8.07, 2.5 g L -1 , 45 °C, and 0.07 mol L -1 , respectively. The adsorption of Cd (II) by IONPs is consistent with pseudo-second order kinetics and Langmuir adsorption isotherm models, indicating that the process of adsorption of Cd (II) by IONPs belongs to monolayer chemical adsorption. The -COOH, -COH, Cπ electron and ≡FeOH may be the binding sites for Cd (II) on the surface of IONPs. Overall, IONPs can be used to remove Cd (II) effectively from aqueous solution in a wide range of conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Egg shell waste as heterogeneous nanocatalyst for biodiesel production: Optimized by response surface methodology.

    Science.gov (United States)

    Pandit, Priti R; Fulekar, M H

    2017-08-01

    Worldwide consumption of hen eggs results in availability of large amount of discarded egg waste particularly egg shells. In the present study, the waste shells were utilized for the synthesis of highly active heterogeneous calcium oxide (CaO) nanocatalyst to transesterify dry biomass into methyl esters (biodiesel). The CaO nanocatalyst was synthesied by calcination-hydration-dehydration technique and fully characterized by infrared spectroscopy, X-ray powder diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), brunauer-emmett-teller (BET) elemental and thermogravimetric analysis. TEM image showed that the nano catalyst had spherical shape with average particle size of 75 nm. BET analysis indicated that the catalyst specific surface area was 16.4 m 2  g -1 with average pore diameter of 5.07 nm. The effect of nano CaO catalyst was investigated by direct transesterification of dry biomass into biodiesel along with other reaction parameters such as catalyst ratio, reaction time and stirring rate. The impact of the transesterification reaction parameters and microalgal biodiesel yield were analyzed by response surface methodology based on a full factorial, central composite design. The significance of the predicted mode was verified and 86.41% microalgal biodiesel yield was reported at optimal parameter conditions 1.7% (w/w), catalyst ratio, 3.6 h reaction time and stirring rate of 140.6 rpm. The biodiesel conversion was determined by 1 H nuclear magnetic resonance spectroscopy (NMR). The fuel properties of prepared biodiesel were found to be highly comply with the biodiesel standard ASTMD6751 and EN14214. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Optimization of Microencapsulation of Human Milk Fat Substitute by Response Surface Methodology.

    Science.gov (United States)

    Li, Xue; Cao, Jun; Bai, Xinpeng; Jiang, Zefang; Shen, Xuanri

    2018-03-09

    Human milk fat substitutes (HMFS) are rich in polyunsaturated fatty acids which upon microencapsulation, can be used as a source of high quality lipids in infant formula. The response surface methodology (RSM) was employed to optimize the microencapsulation condition of HMFS as a functional product. The microencapsulation efficiency (MEE) of microencapsulated HMFS was investigated with respect to four variables including concentration of soy lecithin (A), ratio of demineralized whey powder to malt dextrin (B), HFMS concentration (C), and homogenizing pressure (D). The optimum conditions for efficient microencapsulation of HMFS by the spray drying technique were determined as follows: the amount of soybean lecithin-0.96%, ratio of desalted whey powder to malt dextrin-2.04:1, oil content-17.37% and homogeneous pressure-0.46MPa. Under these conditions, the MEE was 84.72%, and the basic indices of the microcapsules were good. The structure of the microcapsules, as observed by scanning electron microscopy (SEM), revealed spherical, smooth-surfaced capsules with diameters ranging between 10-50 μm. Compared with HFMS, the peroxide value (POV) and acid value (AV) of the microcapsule were significantly lower during storage indicating that the microencapsulation process increases stability and shelf life. Infrared spectroscopic analyses indicated that HFMS had the same characteristic functional groups as the oil extracted from microcapsules. Simulated in vitro digestion revealed that the microcapsules were digested completely within 2h with maximum lipid absorption rate of 64%. Furthermore, these results advocate the embedding process of HFMS by RSM due to its efficacy.

  20. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2016-02-15

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm.

  1. Optimization of Process Variables for Insulation Coating of Conductive Particles by Response Surface Methodology

    International Nuclear Information System (INIS)

    Sim, Chol-Ho

    2016-01-01

    The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data (Adj-R2=0.944). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was 530 kΩ·cm

  2. A Case Study on Maximizing Aqua Feed Pellet Properties Using Response Surface Methodology and Genetic Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Tumuluru, Jaya

    2013-01-10

    Aims: The present case study is on maximizing the aqua feed properties using response surface methodology and genetic algorithm. Study Design: Effect of extrusion process variables like screw speed, L/D ratio, barrel temperature, and feed moisture content were analyzed to maximize the aqua feed properties like water stability, true density, and expansion ratio. Place and Duration of Study: This study was carried out in the Department of Agricultural and Food Engineering, Indian Institute of Technology, Kharagpur, India. Methodology: A variable length single screw extruder was used in the study. The process variables selected were screw speed (rpm), length-to-diameter (L/D) ratio, barrel temperature (degrees C), and feed moisture content (%). The pelletized aqua feed was analyzed for physical properties like water stability (WS), true density (TD), and expansion ratio (ER). Extrusion experimental data was collected by based on central composite design. The experimental data was further analyzed using response surface methodology (RSM) and genetic algorithm (GA) for maximizing feed properties. Results: Regression equations developed for the experimental data has adequately described the effect of process variables on the physical properties with coefficient of determination values (R2) of > 0.95. RSM analysis indicated WS, ER, and TD were maximized at L/D ratio of 12-13, screw speed of 60-80 rpm, feed moisture content of 30-40%, and barrel temperature of = 80 degrees C for ER and TD and > 90 degrees C for WS. Based on GA analysis, a maxium WS of 98.10% was predicted at a screw speed of 96.71 rpm, L/D radio of 13.67, barrel temperature of 96.26 degrees C, and feed moisture content of 33.55%. Maximum ER and TD of 0.99 and 1346.9 kg/m3 was also predicted at screw speed of 60.37 and 90.24 rpm, L/D ratio of 12.18 and 13.52, barrel temperature of 68.50 and 64.88 degrees C, and medium feed moisture content of 33.61 and 38.36%. Conclusion: The present data analysis indicated

  3. Oxygen isotope evidence for sorption of molecular oxygen to pyrite surface sites and incorporation into sulfate in oxidation experiments

    International Nuclear Information System (INIS)

    Tichomirowa, Marion; Junghans, Manuela

    2009-01-01

    Experiments were conducted to investigate (i) the rate of O-isotope exchange between SO 4 and water molecules at low pH and surface temperatures typical for conditions of acid mine drainage (AMD) and (ii) the O- and S-isotope composition of sulfates produced by pyrite oxidation under closed and open conditions (limited and free access of atmospheric O 2 ) to identify the O source/s in sulfide oxidation (water or atmospheric molecular O 2 ) and to better understand the pyrite oxidation pathway. An O-isotope exchange between SO 4 and water was observed over a pH range of 0-2 only at 50 deg. C, whereas no exchange occurred at lower temperatures over a period of 8 a. The calculated half-time of the exchange rate for 50 deg. C (pH = 0 and 1) is in good agreement with former experimental data for higher and lower temperatures and excludes the possibility of isotope exchange for typical AMD conditions (T ≤ 25 deg. C, pH ≥ 3) for decades. Pyrite oxidation experiments revealed two dependencies of the O-isotope composition of dissolved sulfates: O-isotope values decreased with longer duration of experiments and increasing grain size of pyrite. Both changes are interpreted as evidence for chemisorption of molecular O 2 to pyrite surface sites. The sorption of molecular O 2 is important at initial oxidation stages and more abundant in finer grained pyrite fractions and leads to its incorporation in the produced SO 4 . The calculated bulk contribution of atmospheric O 2 in the dissolved SO 4 reached up to 50% during initial oxidation stages (first 5 days, pH 2, fine-grained pyrite fraction) and decreased to less than 20% after about 100 days. Based on the direct incorporation of molecular O 2 in the early-formed sulfates, chemisorption and electron transfer of molecular O 2 on S sites of the pyrite surface are proposed, in addition to chemisorption on Fe sites. After about 10 days, the O of all newly-formed sulfates originates only from water, indicating direct interaction

  4. An experimental strategy validated to design cost-effective culture media based on response surface methodology.

    Science.gov (United States)

    Navarrete-Bolaños, J L; Téllez-Martínez, M G; Miranda-López, R; Jiménez-Islas, H

    2017-07-03

    For any fermentation process, the production cost depends on several factors, such as the genetics of the microorganism, the process condition, and the culture medium composition. In this work, a guideline for the design of cost-efficient culture media using a sequential approach based on response surface methodology is described. The procedure was applied to analyze and optimize a culture medium of registered trademark and a base culture medium obtained as a result of the screening analysis from different culture media used to grow the same strain according to the literature. During the experiments, the procedure quantitatively identified an appropriate array of micronutrients to obtain a significant yield and find a minimum number of culture medium ingredients without limiting the process efficiency. The resultant culture medium showed an efficiency that compares favorably with the registered trademark medium at a 95% lower cost as well as reduced the number of ingredients in the base culture medium by 60% without limiting the process efficiency. These results demonstrated that, aside from satisfying the qualitative requirements, an optimum quantity of each constituent is needed to obtain a cost-effective culture medium. Study process variables for optimized culture medium and scaling-up production for the optimal values are desirable.

  5. Optimization by response surface methodology of lutein recovery from paprika leaves using accelerated solvent extraction.

    Science.gov (United States)

    Kang, Jae-Hyun; Kim, Suna; Moon, BoKyung

    2016-08-15

    In this study, we used response surface methodology (RSM) to optimize the extraction conditions for recovering lutein from paprika leaves using accelerated solvent extraction (ASE). The lutein content was quantitatively analyzed using a UPLC equipped with a BEH C18 column. A central composite design (CCD) was employed for experimental design to obtain the optimized combination of extraction temperature (°C), static time (min), and solvent (EtOH, %). The experimental data obtained from a twenty sample set were fitted to a second-order polynomial equation using multiple regression analysis. The adjusted coefficient of determination (R(2)) for the lutein extraction model was 0.9518, and the probability value (p=0.0000) demonstrated a high significance for the regression model. The optimum extraction conditions for lutein were temperature: 93.26°C, static time: 5 min, and solvent: 79.63% EtOH. Under these conditions, the predicted extraction yield of lutein was 232.60 μg/g. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Optimization of ultrasonic-assisted extraction of natural antioxidants from rice bran using response surface methodology.

    Science.gov (United States)

    Tabaraki, Reza; Nateghi, Ashraf

    2011-11-01

    Ultrasonic technology was applied for extraction of polyphenols and antioxidants from the rice bran using ethanol as a food grade solvent. Response surface methodology (RSM) was used to optimize experimental conditions for extraction of polyphenols and antioxidants. Three independent variables such as solvent percentage (%), temperature (°C) and time (min) were studied. Effect of ethanol concentration was found to be significant on all responses. Total phenolic content (TPC) varied from 2.37 to 6.35mg gallic acid equivalent/g of dry sample. Antioxidant activity of the extracts was determined by the ferric reducing antioxidant power (FRAP) assay and scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. FRAP and DPPH values varied from 31.74 to 57.23μmol Fe(2+)/g of dry sample and 16.88% to 55.61% inhibition, respectively. Extraction yields ranged from 11 to 20.2%. Optimal ultrasonic-assisted extraction (UAE) conditions were identified as 65-67% ethanol, 51-54°C, 40-45min. The experimental values agreed with those predicted by SRM models, thus indicating suitability of the model employed and the success of RSM in optimizing the extraction conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Application of Response Surface Methodology in Development of Sirolimus Liposomes Prepared by Thin Film Hydration Technique

    Directory of Open Access Journals (Sweden)

    Saeed Ghanbarzadeh

    2013-04-01

    Full Text Available Introduction: The present investigation was aimed to optimize the formulating process of sirolimus liposomes by thin film hydration method. Methods: In this study, a 32 factorial design method was used to investigate the influence of two independent variables in the preparation of sirolimus liposomes. The dipalmitoylphosphatidylcholine (DPPC /Cholesterol (Chol and dioleoyl phosphoethanolamine(DOPE /DPPC molar ratios were selected as the independent variables. Particle size (PS and Encapsulation Efficiency (EE % were selected as the dependent variables. To separate the un-encapsulated drug, dialysis method was used. Drug analysis was performed with a validated RP-HPLC method. Results: Using response surface methodology and based on the coefficient values obtained for independent variables in the regression equations, it was clear that the DPPC/Chol molar ratio was the major contributing variable in particle size and EE %. The use of a statistical approach allowed us to see individual and/or interaction effects of influencing parameters in order to obtain liposomes with desired properties and to determine the optimum experimental conditions that lead to the enhancement of characteristics. In the prediction of PS and EE % values, the average percent errors are found to be as 3.59 and 4.09%. This value is sufficiently low to confirm the high predictive power of model. Conclusion: Experimental results show that the observed responses were in close agreement with the predicted values and this demonstrates the reliability of the optimization procedure in prediction of PS and EE % in sirolimus liposomes preparation.

  8. OPTIMIZATION OF REACTIVE BLUE 19 DECOLORIZATION BY GANODERMA SP. USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    1M. Mohammadian Fazli, *1A. R. Mesdaghinia, 1K. Naddafi, 1S. Nasseri , 1M. Yunesian, 2M. Mazaheri Assadi, 3S. Rezaie, 4H. Hamzehei

    2010-01-01

    Full Text Available Synthetic dyes are extensively used in different industries. Dyes have adverse impacts such as visual effects, chemical oxygen demand, toxicity, mutagenicity and carcinogenicity characteristics. White rot fungi, due to extracellular enzyme system, are capable to degrade dyes and various xenobiotics. The aim of this study was to optimize decolorization of reactive blue 19 (RB19 dye using Ganoderma sp. fungus. Response Surface Methodology (RSM was used to study the effect of independent variables, namely glycerol concentration (15, 20 and 25 g/L, temperature (27, 30 and 33 oC and pH (5.5, 6.0 and 6.5 on color removal efficiency in aqueous solution. From RSM-generated model, the optimum conditions for RB19 decolorization were identified to be at temperature of 27oC, glycerol concentration of 19.14 mg/L and pH=6.3. At the optimum conditions, predicted decolorization was 95.3 percent. The confirmatory experiments were conducted and confirmed the results by 94.89% color removal. Thus, this statistical approach enabled to improve reactive blue 19 decolorization process by Ganoderma sp. up to 1.27 times higher than non-optimized conditions.

  9. Arsenic Removal from Natural Groundwater by Electrocoagulation Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    A. M. García-Lara

    2014-01-01

    Full Text Available Contamination of natural groundwater by arsenic (As is a serious problem that appears in some areas of Northern Central Mexico (NCM. In this research, As was removed from NCM wells groundwater by the electrocoagulation (EC technique. Laboratory-scale arsenic electroremoval experiments were carried out at continuous flow rates between 0.25 and 1.00 L min−1 using current densities of 5, 10, and 20 A m−2. Experiments were performed under galvanostatic conditions during 5 min, at constant temperature and pH. The response surface methodology (RSM was used for the optimization of the processing variables (flow rate and current density, response modeling, and predictions. The highest arsenic removal efficiency from underground water (99% was achieved at low flow rates (0.25 L min−1 and high current densities (20 A m−2. The response models developed explained 93.7% variability for As removal efficiency.

  10. Optimization of recombinant β-NGF expression in Escherichia coli using response surface methodology.

    Science.gov (United States)

    Gholami Tilko, Pouria; Hajihassan, Zahra; Moghimi, Hamid

    2017-04-21

    Human nerve growth factor a member of the neurotrophin family can be used to treat neurodegenerative diseases. As it has disulfide bonds in its structure, periplasmic expression of it using appropriate signal sequence is beneficial. Therefore, in this work β-nerve growth factor (β-NGF) was expressed in Escherichia coli using pET39b expression vector containing DsbA signal sequence. In an initial step, the effect of isopropyl β-D-1-thiogalactopyranoside (IPTG) and lactose concentration as inducer on protein production was investigated using response surface methodology. Then the effect of different postinduction time and temperature on protein production was studied. Our results indicated that the highest β-NGF production was achieved with 1 mM IPTG and low concentrations of lactose (0-2% w/v), low cultivation temperature of 25°C and postinduction time of 2 hr. Also following β-NGF purification, bioassay test using PC12 cell line was done. The biological activity of the purified β-NGF showed a similar cell proliferation activity with the standard recombinant human β-NGF. In conclusion, the results indicated an optimized upstream process to obtain high yields of biologically active β-NGF.

  11. Photocatalytic Performance and Degradation Mechanism of Aspirin by TiO2 through Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Lezhuo Li

    2018-03-01

    Full Text Available In the present work, the photocatalytic performance of P25TiO2 was investigated by means of the degradation of aspirin, while the reaction system was systematically optimized by central composite design (CCD based on the response surface methodology (RSM. In addition, three variables of initial pH value, initial aspirin concentration and P25 concentration were selected to assess the dependence of degradation efficiencies of aspirin. Meanwhile, a predicted model of degradation efficiency was estimated and checked using analysis of variance (ANOVA. The results indicated that the PC removal of aspirin by P25 was significantly influenced by all these variables in descending order as follows: P25 concentration > initial aspirin concentration > initial pH value. Moreover, the parameters were optimized by the CCD method. Under the conditions of an initial pH value of 5, initial aspirin concentration of 10 mg/L and P25 concentration of 50 mg/L, the degradation efficiency of aspirin was 98.9%with 60 min of Xenon lamp irradiation. Besides, based on the liquid chromatography-mass spectrometry measurements, two main PC degradation pathways of aspirin by TiO2 were deduced and the tentative degradation mechanism was also proposed.

  12. Deployment of response surface methodology to optimise recovery of grape (Vitis vinifera) stem polyphenols.

    Science.gov (United States)

    Karvela, Evangelia; Makris, Dimitris P; Kalogeropoulos, Nick; Karathanos, Vaios T

    2009-10-15

    A 2(3)-full factorial design and response surface methodology were deployed to assess some basic factors (time, % ethanol and pH) affecting profoundly the extractability of polyphenolic phytochemicals from grape (Vitis vinifera) stems. In an effort to obtain a thorough insight into the applicability of the models established, stem extracts from three different varieties were tested, by determining several indices of the polyphenolic composition, such as total polyphenol (TP), total flavanol (TFl), total flavone (TFn) and proanthocyanidin (PC) concentration. It was shown that the models generated can adequately predict the recovery levels for each polyphenol group, but the optimal conditions predicted for TP, TFl, TFn and PC recovery varied significantly. Notable differences were also seen among the different varieties. Correlation of the polyphenol indices with the antiradical activity and reducing power of the extracts indicated that the PC fraction might exert strong effects, while the influence of other groups was not apparent. Examination of the optimally obtained extracts using liquid chromatography-mass spectrometry revealed that the most prominent compounds were caftaric acid, flavanols and derivatives thereof, as well as dehydroflavonols and flavonols.

  13. An Optimization Study for Transesterification of Palm Oil using Response Surface Methodology (RSM)

    International Nuclear Information System (INIS)

    Wong, Y.C.; Tan, Y.P.; Taufiq-Yap, Y.H.; Ramli, I.; Wong, Y.C.; Tan, Y.P.; Taufiq-Yap, Y.H.; Ramli, I.

    2015-01-01

    Biodiesel was produced via transesterification of palm oil with methanol in the presence of CaO-Nb 2 O 5 mixed oxide catalyst. Response surface methodology (RSM) with central composite design (CCD) was performed to determine the optimum operating conditions and to optimize the biodiesel yield. In this study, the reaction variables being optimized were reaction time, catalyst loading and methanol to oil molar ratio. From the analysis of variance (ANOVA), the most influential parameter on biodiesel production was reaction time. The predicted yield was found in good agreement with the experimental value, with R2= 0.9902. The optimum biodiesel yield of 97.67% was achieved at 2.67 h reaction time, with 3.60 wt. % of catalyst and with methanol to oil molar ratio of 13.04. The high biodiesel yield can be correlated to the synergic effect of basicity between the metallic ions of CaO-Nb 2 O 5 shown in the physicochemical analysis. (author)

  14. Extraction, stability, and separation of betalains from Opuntia joconostle cv. using response surface methodology.

    Science.gov (United States)

    Sanchez-Gonzalez, Noe; Jaime-Fonseca, Monica R; San Martin-Martinez, Eduardo; Zepeda, L Gerardo

    2013-12-11

    Betalains were extracted and analyzed from Opuntia joconostle (the prickly pear known as xoconostle in Mexico). For the extraction, two solvent systems were used, methanol/water and ethanol/water. A three-variable Box-Behnken statistical design was used for extraction: solvent concentration (0-80%, v/v), temperature (5-30 °C), and treatment time (10-30 min). The extraction and stability of betalains from xoconostle were studied using response surface methodology (RSM). Techniques such as UV-vis, column chromatography, and HPLC were employed for the separation and analysis of the main pigments present in the extracts. Maximum pigment concentration (92 mg/100 g of fruit) was obtained at a temperature of 15 °C and a time of 10 min for methanol/water (20:80), whereas maximum stability of the pigment was observed at pH 5 and a temperature of 25 °C. HPLC chromatograms showed the main betalains of the xoconostle characterized were betalain, betanidin, and isobetalain.

  15. Optimization of photocatalytic degradation of real textile dye house wastewater by response surface methodology.

    Science.gov (United States)

    Hosseini, Sayed Mohammad Bagher; Fallah, Narges; Royaee, Sayed Javid

    2016-11-01

    This study evaluates the advanced oxidation process for decolorization of real textile dyeing wastewater containing azo and disperse dye by TiO 2 and UV radiation. Among effective parameters on the photocatalytic process, effects of three operational parameters (TiO 2 concentration, initial pH and aeration flow rate) were examined with response surface methodology. The F-value (136.75) and p-value degradation and subsequent analysis of variance (ANOVA) test using Design Expert software, the concentration of catalyst was found to be the most influential factor, while all the other factors were also significant. To achieve maximum dye removal, optimum conditions were found at TiO 2 concentration of 3 g L -1 , initial pH of 7 and aeration flow rate of 1.50 L min -1 . Under the conditions stated, the percentages of dye and chemical oxygen demand removal were 98.50% and 91.50%, respectively. Furthermore, the mineralization test showed that total organic compounds removal was 91.50% during optimum conditions.

  16. Warpage optimization on a mobile phone case using response surface methodology (RSM)

    Science.gov (United States)

    Lee, X. N.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.; Shazzuan, S.

    2017-09-01

    Plastic injection moulding is a popular manufacturing method not only it is reliable, but also efficient and cost saving. It able to produce plastic part with detailed features and complex geometry. However, defects in injection moulding process degrades the quality and aesthetic of the injection moulded product. The most common defect occur in the process is warpage. Inappropriate process parameter setting of injection moulding machine is one of the reason that leads to the occurrence of warpage. The aims of this study were to improve the quality of injection moulded part by investigating the optimal parameters in minimizing warpage using Response Surface Methodology (RSM). Subsequent to this, the most significant parameter was identified and recommended parameters setting was compared with the optimized parameter setting using RSM. In this research, the mobile phone case was selected as case study. The mould temperature, melt temperature, packing pressure, packing time and cooling time were selected as variables whereas warpage in y-direction was selected as responses in this research. The simulation was carried out by using Autodesk Moldflow Insight 2012. In addition, the RSM was performed by using Design Expert 7.0. The warpage in y direction recommended by RSM were reduced by 70 %. RSM performed well in solving warpage issue.

  17. Optimization of Chitinase Production by Bacillus pumilus Using Plackett-Burman Design and Response Surface Methodology.

    Science.gov (United States)

    Tasharrofi, Noshin; Adrangi, Sina; Fazeli, Mehdi; Rastegar, Hossein; Khoshayand, Mohammad Reza; Faramarzi, Mohammad Ali

    2011-01-01

    A soil bacterium capable of degrading chitin on chitin agar plates was isolated and identified as Bacillus pumilus isolate U5 on the basis of 16S rDNA sequence analysis. In order to optimize culture conditions for chitinase production by this bacterium, a two step approach was employed. First, the effects of several medium components were studied using the Plackett-Burman design. Among various components tested, chitin and yeast extract showed positive effect on enzyme production while MgSO4 and FeSO4 had negative effect. However, the linear model proved to be insufficient for determining the optimum levels for these components due to a highly significant curvature effect. In the second step, Box-Behnken response surface methodology was used to determine the optimum values. It was noticed that a quadratic polynomial equation fitted he experimental data appropriately. The optimum concentrations for chitin, yeast extract, MgSO4 and FeSO4 were found to be 4.76, 0.439, 0.0055 and 0.019 g/L, respectively, with a predicted value of chitinase production of 97.67 U/100 mL. Using this statistically optimized medium, the practical chitinase production reached 96.1 U/100 mL.

  18. [Optimization of one-step pelletization technology of Fuke IV granules with response surface methodology].

    Science.gov (United States)

    Liu, Dan; He, Feng-Jun; Liu, Chang-Long; Liu, Jun-Chao; Wu, Yun; Wang, Zhen-Zhong; Xiao, Wei

    2016-01-01

    To optimize the one-step pelletization technology of Fuke IV (FKIV) granules by response surface methodology. With the qualified rate of granules as evaluation indexes, 6 factors affecting one-step pelletization technology were investigated, significant levels of each factor were evaluated and the primal influential factors were determined by Plackett-Burman experimental design. According to the Plackett-Burman experimental design, the qualified rates of granules, moisture capacity and angle of repose as the evaluation indexes, Box-Behnken design with three levels and three factors was established for quadratic regression fitting of the models. Then the experimental results were optimized by Response Optimizer. The best process conditions were determined as follows: the extract relative density of 1.20, inlet air temperature of 88 ℃, and atomization pressure of 0.28 MPa. FKIV granules were prepared by the optimized experimental scheme. The determined qualified rate, moisture capacity and angle of response were 93.65%, 3.76% and 23.19° respectively for the granules, basically similar to the predicted values, indicating that the optimal process conditions were in line with the manufacturing requirements. Copyright© by the Chinese Pharmaceutical Association.

  19. Homogenate Extraction of Crocins from Saffron Optimized by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Yingpeng Tong

    2018-01-01

    Full Text Available Saffron, which has many kinds of biological activities, has been widely used in medicine, cosmetics, food, and other fields of health promotion industries. Crocins are the main component of saffron (Crocus sativus L.. At present, most of the extraction methods for crocins require long time or special instruments to complete the process and some of them are not suitable for industrial production at present. In this article, homogenate extraction technology which is a convenient and efficient method was developed for crocins extraction from saffron. Firstly, the influences of extraction voltage, extraction time, ethanol concentration, and temperature on crocins yield were studied by single factor experiments; and then response surface methodology (RSM was used to optimize levels of four variables based on the result of single factor experiments. Results showed that the optimum extraction process conditions for crocins were as follows: extraction voltage, 110 V; ethanol concentration, 70%; extraction temperature, 57°C; and extraction time, 40 s. Based on these conditions, the extraction yield of crocins can reach 22.76% which is higher than ultrasonic extraction method. Therefore, homogenate extraction is an effective way to extract crocins from saffron with higher extraction yield and shorter extraction time.

  20. Improvement of Folate Biosynthesis by Lactic Acid Bacteria Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Norfarina Muhamad Nor

    2010-01-01

    Full Text Available Lactic acid bacteria (Lactococcus lactis NZ9000, Lactococcus lactis MG1363, Lactobacillus plantarum I-UL4 and Lactobacillus johnsonii DSM 20553 have been screened for their ability to produce folate intracellularly and/or extracellularly. L. plantarum I-UL4 was shown to be superior producer of folate compared to other strains. Statistically based experimental designs were used to optimize the medium formulation for the growth of L. plantarum I-UL4 and folate biosynthesis. The optimal values of important factors were determined by response surface methodology (RSM. The effects of carbon sources, nitrogen sources and para-aminobenzoic acid (PABA concentrations on folate biosynthesis were determined prior to RSM study. The biosynthesis of folate by L. plantarum I-UL4 increased from 36.36 to 60.39 µg/L using the optimized medium formulation compared to the selective Man de Rogosa Sharpe (MRS medium. Conditions for the optimal growth of L. plantarum I-UL4 and folate biosynthesis as suggested by RSM were as follows: lactose 20 g/L, meat extract 16.57 g/L and PABA 10 µM.

  1. Employing response surface methodology (RSM) to improve methane production from cotton stalk.

    Science.gov (United States)

    Zhang, Han; Khalid, Habiba; Li, Wanwu; He, Yanfeng; Liu, Guangqing; Chen, Chang

    2018-03-01

    China is the largest cotton producer with the cotton output accounting for 25% of the total world's cotton production. A large quantity of cotton stalk (CS) waste is generated which is burned and causes environmental and ecological problems. This study investigated the anaerobic digestibility of CS by focusing on improving the methane yield by applying central composite design of response surface methodology (RSM). The purpose of this study was to determine the best level of factors to optimize the desired output of methane production from CS. Thus, it was necessary to describe the relationship of many individual variables with one or more response values for the effective utilization of CS. The influences of feed to inoculum (F/I) ratio and organic loading (OL) on methane production were investigated. Results showed that the experimental methane yield (EMY) and volatile solid (VS) removal were calculated to be 70.22 mL/gVS and 14.33% at F/I ratio of 0.79 and organic loading of 25.61 gVS/L, respectively. Characteristics of final effluent showed that the anaerobic system was stable. This research laid a foundation for future application of CS to alleviate the problems of waste pollution and energy output.

  2. Optimization of enzymatic esterification of dihydrocaffeic acid with hexanol in ionic liquid using response surface methodology.

    Science.gov (United States)

    Gholivand, Somayeh; Lasekan, Ola; Tan, Chin Ping; Abas, Faridah; Wei, Leong Sze

    2017-05-26

    Developing an efficient lipophilization reaction system for phenolic derivatives could enhance their applications in food processing. Low solubility of phenolic acids reduces the efficiency of phenolic derivatives in most benign enzyme solvents. The conversion of phenolic acids through esterification alters their solubility and enhances their use as food antioxidant additives as well as their application in cosmetics. This study has shown that lipase-catalyzed esterification of dihydrocaffeic acid with hexanol in ionic liquid (1-butyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide) was the best approach for esterification reaction. In order to achieve the maximum yield, the process was optimized by response surface methodology (RSM) based on a five-level and four independent variables such as: dosage of enzyme; hexanol/dihydrocaffeic acid mole ratio; temperature and reaction time. The optimum esterification condition (Y = 84.4%) was predicted to be obtained at temperature of 39.4 °C, time of 77.5 h dosage of enzyme at 41.6% and hexanol/dihydrocaffeic acid mole ratio of 2.1. Finally, this study has produced an efficient enzymatic esterification method for the preparation of hexyl dihydrocaffeate in vitro using a lipase in an ionic liquid system. Concentration of hexanol was the most significant (p < 0.05) independent variable that influenced the yield of hexyl dihydrocaffeate. Graphical abstract Synthesis of different Hexyl dihydrocaffeates in ionic liquid.

  3. Optimization of lipase-catalyzed enantioselective production of 1-phenyl 1-propanol using response surface methodology.

    Science.gov (United States)

    Soyer, Asli; Bayraktar, Emine; Mehmetoglu, Ulku

    2010-01-01

    Optically active 1-phenyl 1-propanol is used as a chiral building block and synthetic intermediate in the pharmaceutical industries. In this study, the enantioselective production of 1-phenyl 1-propanol was investigated systematically using response surface methodology (RSM). Before RSM was applied, the effects of the enzyme source, the type of acyl donor, and the type of solvent on the kinetic resolution of 1-phenyl 1-propanol were studied. The best results were obtained with Candida antartica lipase (commercially available as Novozym 435), vinyl laurate as the acyl donor, and isooctane as the solvent. In the RSM, substrate concentration, molar ratio of acyl donor to the substrate, amount of enzyme, temperature, and stirring rate were chosen as independent variables. The predicted optimum conditions for a higher enantiomeric excess (ee) were as follows: substrate concentration, 233 mM; molar ratio of acyl donor to substrate, 1.5; enzyme amount, 116 mg; temperature, 47 °C; and stirring rate, 161 rpm. A verification experiment conducted at these optimized conditions for maximum ee yielded 91% for 3 hr, which is higher than the predicted value of 83%. The effect of microwave on the ee was also investigated and ee reached 87% at only 5 min.

  4. Optimization of Reactor Temperature and Catalyst Weight for Plastic Cracking to Fuels Using Response Surface Methodology

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    Istadi Istadi

    2011-01-01

    Full Text Available The present study deals with effect of reactor temperature and catalyst weight on performance of plastic waste cracking to fuels over modified catalyst waste as well as their optimization. From optimization study, the most operating parameters affected the performance of the catalytic cracking process is reactor temperature followed by catalyst weight. Increasing the reactor temperature improves significantly the cracking performance due to the increasing catalyst activity. The optimal operating conditions of reactor temperature about 550 oC and catalyst weight about 1.25 gram were produced with respect to maximum liquid fuel product yield of 29.67 %. The liquid fuel product consists of gasoline range hydrocarbons (C4-C13 with favorable heating value (44,768 kJ/kg. ©2010 BCREC UNDIP. All rights reserved(Received: 10th July 2010, Revised: 18th September 2010, Accepted: 19th September 2010[How to Cite: I. Istadi, S. Suherman, L. Buchori. (2010. Optimization of Reactor Temperature and Catalyst Weight for Plastic Cracking to Fuels Using Response Surface Methodology. Bulletin of Chemical Reaction Engineering and Catalysis, 5(2: 103-111. doi:10.9767/bcrec.5.2.797.103-111][DOI: http://dx.doi.org/10.9767/bcrec.5.2.797.103-111 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/797

  5. Extraction optimization of mucilage from Basil (Ocimum basilicum L. seeds using response surface methodology

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    Sadaf Nazir

    2017-05-01

    Full Text Available Aqueous extraction of basil seed mucilage was optimized using response surface methodology. A Central Composite Rotatable Design (CCRD for modeling of three independent variables: temperature (40–91 °C; extraction time (1.6–3.3 h and water/seed ratio (18:1–77:1 was used to study the response for yield. Experimental values for extraction yield ranged from 7.86 to 20.5 g/100 g. Extraction yield was significantly (P < 0.05 affected by all the variables. Temperature and water/seed ratio were found to have pronounced effect while the extraction time was found to have minor possible effects. Graphical optimization determined the optimal conditions for the extraction of mucilage. The optimal condition predicted an extraction yield of 20.49 g/100 g at 56.7 °C, 1.6 h, and a water/seed ratio of 66.84:1. Optimal conditions were determined to obtain highest extraction yield. Results indicated that water/seed ratio was the most significant parameter, followed by temperature and time.

  6. Optimization of alkaline and dilute acid pretreatment of agave bagasse by response surface methodology

    Directory of Open Access Journals (Sweden)

    Abimael I. Ávila-Lara

    2015-09-01

    Full Text Available Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA and alkaline (AL catalyst providing specific effects on the physicochemical structure of the biomass such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15% since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification which will be reflected in lower capital costs, however this data is currently limited. In this study, several variables such as catalyst loading, retention time and solids loading, were studied using Response Surface Methodology (RSM based on a factorial Central Composite Design (CCD of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS yield. Pretreated biomass

  7. Aroma profile design of wine spirits: Multi-objective optimization using response surface methodology.

    Science.gov (United States)

    Matias-Guiu, Pau; Rodríguez-Bencomo, Juan José; Pérez-Correa, José R; López, Francisco

    2018-04-15

    Developing new distillation strategies can help the spirits industry to improve quality, safety and process efficiency. Batch stills equipped with a packed column and an internal partial condenser are an innovative experimental system, allowing a fast and flexible management of the rectification. In this study, the impact of four factors (heart-cut volume, head-cut volume, pH and cooling flow rate of the internal partial condenser during the head-cut fraction) on 18 major volatile compounds of Muscat spirits was optimized using response surface methodology and desirability function approaches. Results have shown that high rectification at the beginning of the heart-cut enhances the overall positive aroma compounds of the product, reducing off-flavor compounds. In contrast, optimum levels of heart-cut volume, head-cut volume and pH factors varied depending on the process goal. Finally, three optimal operational conditions (head off-flavors reduction, flowery terpenic enhancement and fruity ester enhancement) were evaluated by chemical and sensory analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Pyrolysis of low density polyethylene waste in subcritical water optimized by response surface methodology.

    Science.gov (United States)

    Wong, S L; Ngadi, N; Amin, N A S; Abdullah, T A T; Inuwa, I M

    2016-01-01

    Pyrolysis of low density polyethylene (LDPE) waste from local waste separation company in subcritical water was conducted to investigate the effect of reaction time, temperature, as well as the mass ratio of water to polymer on the liquid yield. The data obtained from the study were used to optimize the liquid yield using response surface methodology. The range of reaction temperature used was 162-338°C, while the reaction time ranged from 37 min to 143 min, and the ratio of water to polymer ranged from 1.9 to 7.1. It was found that pyrolysis of LDPE waste in subcritical water produced hydrogen, methane, carbon monoxide and carbon dioxide, while the liquid product contained alkanes and alkenes with 10-50 carbons atoms, as well as heptadecanone, dichloroacetic acid and heptadecyl ester. The optimized conditions were 152.3°C, reaction time of 1.2 min and ratio of water solution to polymer of 32.7, with the optimum liquid yield of 13.6 wt% and gases yield of 2.6 wt%.

  9. Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology.

    Science.gov (United States)

    Xue, Juan Qin; Liu, Ni Na; Li, Guo Ping; Dang, Long Tao

    To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.

  10. Application of Response Surface Methodology to Optimize Malachite Green Removal by Cl-nZVI Nanocomposites

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    Farshid Ghorbani

    2017-09-01

    Full Text Available Disposal of effluents containing dyes into natural ecosystems pose serious threats to both the environment and its aquatic life. Malachite green (MG is a basic dye that has extensive industrial applications, especially in aquaculture, throughout the world. This study reports on the application of the central composite design (CCD under the response surface methodology (RSM for the optimization of MG adsorption from aqueous solutions using the clinoptilolite nano-zerovalence iron (Cl-nZVI nanocomposites. The sorbent structures produced are characterized by means of scanning electron micrograph (SEM, energy-dispersive X-ray spectroscopy (EDS, and vibrating sample magnetometer (VSM. The effects of different parameters including pH, initial MG concentration, and sorbent dosage on the removal efficiency (R of MG were studied to find the optimum operating conditions. For this purpose, a total of 20 sets of experiments were designed by the Design Expert.7.0 software and the values of removal efficiency were used as input response to the software. The optimum pH, initial MG concentration, and sorbent dosage were found to be 5.6, 49.21 mg.L-1, and 1.43 g.L-1, respectively. A high MG removal efficiency (57.90% was obtained with optimal process parameters. Moreover, a desirability value of 0.963 was obtained for the optimization process.

  11. Optimization of Preparation Conditions for Lysozyme Nanoliposomes Using Response Surface Methodology and Evaluation of Their Stability

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    Zhipan Wu

    2016-06-01

    Full Text Available The main purpose of this study was to optimize the preparation of lysozyme nanoliposomes using response surface methodology and measure their stability. The stabilities of lysozyme nanoliposomes in simulated gastrointestinal fluid (SGF, simulated intestinal fluid (SIF, as well as pH, temperature and sonication treatment time were evaluated. Reverse-phase evaporation method is an easy, speedy, and beneficial approach for nanoliposomes’ preparation and optimization. The optimal preparative conditions were as follows: phosphatidylcholine-to-cholesterol ratio of 3.86, lysozyme concentration of 1.96 mg/mL, magnetic stirring time of 40.61 min, and ultrasound time of 14.15 min. At the optimal point, encapsulation efficiency and particle size were found to be 75.36% ± 3.20% and 245.6 nm ± 5.2 nm, respectively. The lysozyme nanoliposomes demonstrated certain stability in SGF and SIF at a temperature of 37 °C for 4 h, and short sonication handling times were required to attain nano-scaled liposomes. Under conditions of high temperature, acidity and alkalinity, lysozyme nanoliposomes are unstable.

  12. Development of fibre-enriched gluten-free bread: a response surface methodology study.

    Science.gov (United States)

    Sabanis, Dimitrios; Lebesi, Dimitra; Tzia, Constantina

    2009-01-01

    The enrichment of gluten-free (GF) baked products with dietary fibre (DF) seems to be necessary since it has been reported that coeliac patients have generally a low intake of DF due to their GF diet. Response surface methodology was used to optimize a fibre-enriched GF bread formulation based on corn starch, rice flour and hydroxypropylmethyl cellulose. Maize fibre and water were the predictor variables (factors), and loaf specific volume, crumb firmness and crumb L value were the dependent variables (responses) used to assess the product quality. The optimal formulation, determined from the data, contained 6.5% maize fibre and 102.5% water, starch/flour base. The developed mathematical models for the measured responses could be successfully used for their prediction during baking. Shelf-life study of the optimized formulation revealed that bread stored under modified atmosphere packaging exhibited lower crumb firmness and moisture content values, and thus remained softer through storage. Scanning electron microscopy of the crumb showed a continuum matrix between starch and maize fibre, in the optimized formulation, obtaining a more aerated structure.

  13. Production of Sterilizing Agents from Calendula officinalis Extracts Optimized by Response Surface Methodology.

    Science.gov (United States)

    Goktas, Fatih Mehmet; Sahin, Bilgesu; Yigitarslan, Sibel

    2015-01-01

    The aim of this study was to produce hand sterilizing liquid and wet wipes with the extracts of Calendula officinalis. Since this plant has well known antimicrobial activity due to its phytochemical constituents, the increase in the extraction yield was chosen as the principle part of the production process. To achieve the maximum yield, parameters of solid-to-liquid ratio, extraction temperature, and time were studied. The optimum conditions were determined by response surface methodology as 41°C, 7 h, and 3.3 g/200 mL for temperature, time, and solid-to-liquid ratio, respectively. The yield achieved at those conditions was found to be 90 percent. The highest amounts of flavonoids were detected at optimum, whereas the highest triterpene and saponin constituents were determined at different design points. The microbial efficiencies of extracts were determined by the inhibition of the growth of selected microorganisms. Different dilution rates and interaction times were used as parameters of inhibition. Not any of the constituent but symbiotic relation in-between reached the highest inhibition of 90 percent. The pH values of the extracts were 5.1 to 5.4. As a result, the extraction of Calendula officinalis at the optimum conditions can be used effectively in the production of wet wipes and hand sterilizing liquid.

  14. Optimization of protease extraction from horse mango (Mangifera foetida Lour) kernels by a response surface methodology.

    Science.gov (United States)

    Ahmad, Mohammad Norazmi; Liew, Siew Ling; Yarmo, Mohd Ambar; Said, Mamot

    2012-01-01

    Protease is one of the most important industrial enzymes with a multitude of applications in both food and non-food sectors. Although most commercial proteases are microbial proteases, the potential of non-conventional protease sources, especially plants, should not be overlooked. In this study, horse mango (Mangifera foetida Lour) fruit, known to produce latex with a blistering effect upon contact with human skin, was chosen as a source of protease, and the effect of the extraction process on its protease activity evaluated. The crude enzyme was extracted from the kernels and extraction was optimized by a response surface methodology (RSM) using a central composite rotatable design (CCRD). The variables studied were pH (x(1)), CaCl(2) (x(2)), Triton X-100 (x(3)), and 1,4-dithryeitol (x(4)). The results obtained indicate that the quadratic model is significant for all the variables tested. Based on the RSM model generated, optimal extraction conditions were obtained at pH 6.0, 8.16 mM CaCl(2), 5.0% Triton X-100, and 10.0 mM DTT, and the estimated response was 95.5% (w/w). Verification test results showed that the difference between the calculated and the experimental protease activity value was only 2%. Based on the t-value, the effects of the variables arranged in ascending order of strength were CaCl(2) < pH < DTT < Triton X-100.

  15. Formulation and optimization of mucoadhesive buccal patches of losartan potassium by using response surface methodology

    Science.gov (United States)

    Ikram, Md.; Gilhotra, Neeraj; Gilhotra, Ritu Mehra

    2015-01-01

    Background: This study was undertaken with an aim to systematically design a model of factors that would yield an optimized sustained release dosage form of an anti-hypertensive agent, losartan potassium, using response surface methodology (RSM) by employing 32 full factorial design. Materials and Methods: Mucoadhesive buccal patches were prepared using different grades of hydroxypropyl methylcellulose (HPMC) (K4M and K100M) and polyvinylpyrrolidone-K30 by solvent casting method. The amount of the release retardant polymers – HPMC K4M (X1) and HPMC K100M (X2) was taken as an independent variable. The dependent variables were the burst release in 30 min (Y1), cumulative percentage release of drug after 8 h (Y2) and swelling index (Y3) of the patches. In vitro release and swelling studies were carried out and the data were fitted to kinetic equations. Results: The physicochemical, bioadhesive, and swelling properties of patches were found to vary significantly depending on the viscosity of the polymers and their combination. Patches showed an initial burst release preceding a more gradual sustained release phase following a nonfickian diffusion process. Discussion: The results indicate that suitable bioadhesive buccal patches with desired permeability could be prepared, facilitated with the RSM. PMID:26682205

  16. Optimization of solvent extraction of shea butter (Vitellaria paradoxa) using response surface methodology and its characterization.

    Science.gov (United States)

    Ajala, E O; Aberuagba, F; Olaniyan, A M; Onifade, K R

    2016-01-01

    Shea butter (SB) was extracted from its kernel by using n-hexane as solvent in an optimization study. This was to determine the optima operating variables that would give optimum yield of SB and to study the effect of solvent on the physico-chemical properties and chemical composition of SB extracted using n-hexane. A Box-behnken response surface methodology (RSM) was used for the optimization study while statistical analysis using ANOVA was used to test the significance of the variables for the process. The variables considered for this study were: sample weight (g), solvent volume (ml) and extraction time (min). The physico-chemical properties of SB extracted were determined using standard methods and Fourier Transform Infrared Spectroscopy (FTIR) for the chemical composition. The results of RSM analysis showed that the three variables investigated have significant effect (p shea butter extracted using traditional method (SBT) showed that it is a more suitable raw material for food, biodiesel production, cosmetics, medicinal and pharmaceutical purposes than shea butter extracted using solvent extraction method (SBS). Fourier Transform Infrared Spectroscopy (FTIR) results obtained for the two samples were similar to what was obtainable from other vegetable oil.

  17. MODELING OF EXTRUSION PROCESS USING RESPONSE SURFACE METHODOLOGY AND ARTIFICIAL NEURAL NETWORKS

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    NEELAM SHIHANI

    2006-06-01

    Full Text Available Artificial neural networks are a powerful tool for modeling of extrusion processing of food materials. Wheat flour and wheat– black soybean blend (95:5 were extruded in a single screw Brabender extruder with varying temperature (120 and 140 oC, dry basis moisture content (18 and 20% and screw speed (156, 168, 180, 192 and 204 rpm. The specific mechanical energy, water absorption index, water solubility index, expansion ratio and sensory characteristics (crispness, hardness, appearance and overall acceptability were measured. Well expanded products could be obtained from wheat flour as well as the blend of wheat– black soybean. The results showed that artificial neural network (ANN models performed better than the response surface methodology (RSM models in describing the extrusion process and characteristics of the extruded product in terms of specific mechanical energy requirement, expansion ratio, water absorption index, water solubility index as well the sensory characteristics. The ANN models were better than RSM models both in case of the individual as well as the pooled data of wheat flour and wheat- black soybean extrusion.

  18. Modelling and optimization of process variables for the solution polymerization of styrene using response surface methodology

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    Rasheed Uthman Owolabi

    2018-01-01

    Full Text Available A satisfactory model for predicting monomer conversion in free radical polymerization has been a challenge due to the complexity and rigors associated with classical kinetic models. This renders the usage of such model an exciting endeavour in the academia but not exactly so in industrial practice. In this study, the individual and interactive effects of three processing conditions (reaction temperature, reaction time and initiator concentration on monomer conversion in the solution polymerization of styrene using acetone as solvent was investigated in a batch reactor through the central composite design (CCD model of response surface methodology (RSM for experimental design, modelling and process optimization. The modelled optimization conditions are: reaction time of 30 min, reaction temperature of 120 °C, and initiator concentration of 0.1135 mol/l, with the corresponding monomer conversion of 76.82% as compared to the observed conversion of 70.86%. A robust model for predicting monomer conversion that is very suitable for routine industrial usage is thus obtained.

  19. Optimization of coagulation-flocculation treatment on paper-recycling wastewater: Application of response surface methodology.

    Science.gov (United States)

    Birjandi, Noushin; Younesi, Habibollah; Bahramifar, Nader; Ghafari, Shahin; Zinatizadeh, Ali Akbar; Sethupathi, Sumathi

    2013-01-01

    The application of coagulation-flocculation (CF) process for treating the paper-recycling wastewater in jar-test experiment was employed. The purpose of the study was aimed to examine the efficiency of alum and poly aluminum chloride (PACl) in combination with a cationic polyacrylamide (C-PAM) in removal of chemical oxygen demand (COD) and turbidity from paper-recycling wastewater. Optimization of CF process were performed by varying independent parameters (coagulants dosage, flocculants dosage, initial COD and pH) using a central composite design (CCD) under response surface methodology (RSM). Maximum set required 4.5 as pH, 40 mg/L coagulants dosage and 4.5 mg/L flocculants dosage at which gave 92% reduction of turbidity, 97% of COD removal and SVI 80 mL/g. The best coagulant and flocculants were alum and chemfloc 3876 at dose of 41 and 7.52 mg/L, respectively, correspondingly at pH of 6.85. These conditions gave 91.30% COD and 95.82% turbidity removals and 12 mL/g SVI.

  20. Response surface methodology-based optimisation of agarose gel electrophoresis for screening and electropherotyping of rotavirus.

    Science.gov (United States)

    Mishra, Vikas; Nag, Vijaya Lakshmi; Tandon, Ritu; Awasthi, Shally

    2010-04-01

    Management of rotavirus diarrhoea cases and prevention of nosocomial infection require rapid diagnostic method at the patient care level. Diagnostic tests currently available are not routinely used due to economic or sensitivity/specificity constraints. Agarose-based sieving media and running conditions were modulated by using central composite design and response surface methodology for screening and electropherotyping of rotaviruses. The electrophoretic resolution of rotavirus genome was calculated from input parameters characterising the gel matrix structure and running conditions. Resolution of rotavirus genome was calculated by densitometric analysis of the gel. The parameters at critical values were able to resolve 11 segmented rotavirus genome. Better resolution and electropherotypic variation in 11 segmented double-stranded RNA genome of rotavirus was detected at 1.96% (w/v) agarose concentration, 0.073 mol l(-1) ionic strength of Tris base-boric acid-ethylenediamine tetraacetic acid buffer (1.4x) and 4.31 h of electrophoresis at 4.6 V cm(-1) electric field strength. Modified agarose gel electrophoresis can replace other methods as a simplified alternative for routine detection of rotavirus where it is not in practice.

  1. Optimization of HNO3leaching of copper from old AMD Athlon processors using response surface methodology.

    Science.gov (United States)

    Javed, Umair; Farooq, Robina; Shehzad, Farrukh; Khan, Zakir

    2018-04-01

    The present study investigates the optimization of HNO 3 leaching of Cu from old AMD Athlon processors under the effect of nitric acid concentration (%), temperature (°C) and ultrasonic power (W). The optimization study is carried out using response surface methodology with central composite rotatable design (CCRD). The ANOVA study concludes that the second degree polynomial model is fitted well to the fifteen experimental runs based on p-value (0.003), R 2 (0.97) and Adj-R 2 (0.914). The study shows that the temperature is the most significant process variable to the leaching concentration of Cu followed by nitric acid concentration. However, ultrasound power shows no significant impact on the leaching concentration. The optimum conditions were found to be 20% nitric acid concentration, 48.89 °C temperature and 5.52 W ultrasound power for attaining maximum concentration of 97.916 mg/l for Cu leaching in solution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Response Surface Methodology for Ultrasound-Assisted Extraction of Astaxanthin from Haematococcus pluvialis

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    Hong-Fu Wu

    2013-05-01

    Full Text Available Astaxanthin is a novel carotenoid nutraceutical occurring in many crustaceans and red yeasts. It has exhibited various biological activities including prevention or amelioration of cardiovascular disease, gastric ulcer, hypertension, and diabetic nephropathy. In this study, ultrasound-assisted extraction was developed for the effective extraction of astaxanthin from Haematococcus pluvialis. Some parameters such as extraction solvent, liquid-to-solid ratio, extraction temperature, and extraction time were optimized by single-factor experiment and response surface methodology. The optimal extraction conditions were 48.0% ethanol in ethyl acetate, the liquid-to-solid ratio was 20:1 (mL/g, and extraction for 16.0 min at 41.1 °C under ultrasound irradiation of 200 W. Under optimal conditions, the yield of astaxanthin was 27.58 ± 0.40 mg/g. The results obtained are beneficial for the full utilization of Haematococcus pluvialis, which also indicated that ultrasound-assisted extraction is a very useful method for extracting astaxanthin from marine life.

  3. OPTIMIZATION OF POTASSIUM NITRATE BASED SOLID PROPELLANT GRAINS FORMULATION USING RESPONSE SURFACE METHODOLOGY

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    Oladipupo Olaosebikan Ogunleye

    2015-08-01

    Full Text Available This study was designed to evaluate the effect of propellant formulation and geometry on the solid propellant grains internal ballistic performance using core, bates, rod and tubular and end-burn geometries. Response Surface Methodology (RSM was used to analyze and optimize the effect of sucrose, potassium nitrate and carbon on the chamber pressure, temperature, thrust and specific impulse of the solid propellant grains through Central Composite Design (CCD of the experiment. An increase in potassium nitrate increased the specific impulse while an increase in sucrose and carbon decreased specific impulse. The coefficient of determination (R2 for models of chamber pressure, temperature, thrust and specific impulse in terms of composition and geometry were 0.9737, 0.9984, 0.9745 and 0.9589, respectively. The optimum specific impulse of 127.89 s, pressure (462201 Pa, temperature (1618.3 K and thrust (834.83 N were obtained using 0.584 kg of sucrose, 1.364 kg of potassium nitrate and 0.052 kg of carbon as well as bate geometry. There was no significant difference between the calculated and experimented ballistic properties at p < 0.05. The bate grain geometry is more efficient for minimizing the oscillatory pressure in the combustion chamber.

  4. An investigation on impact resistance of FDM processed Nylon-12 parts using response surface methodology

    Science.gov (United States)

    Kamoona, Salam Nori; Masood, Syed Hasan; Mohamed, Omar Ahmed

    2017-07-01

    Fused Deposition Modelling (FDM) is one of the leading additive manufacturing processes for plastic part manufacturing. However, engineers often face difficulties to specify the actual levels of process parameters in FDM process to achieve the proper mechanical properties of FDM fabricated parts. The effect of large number of FDM process parameters and the interaction among them need to be understood to achieve desired level of mechanical performance. This paper presents a study on the influence of three FDM process parameters (air gap, raster angle, and build orientation) on the impact strength and mechanical properties of the FDM Nylon 12 fabricated parts by Fortus 450mc FDM machine. The Response Surface Methodology (RSM) based on face centered central composite design was used to analyse, validate, and optimize the results. The significance of parameters was statistically validated with the analysis of variance (ANOVA) technique. The results show that the part build Y-orientations (flat) at 0° and 45° have a significant directly proportional influence on the impact strength, while Z-orientation (upright) at 90° has indirectly proportional effect on the impact strength. Moreover, raster angle has a much significant directly proportional influence on the impact strength at 0° and 60° angles and indirectly proportion influence at 30°.

  5. Examination of Pb2+ bio-sorption onto Rhodotorula mucilaginosa using response surface methodology.

    Science.gov (United States)

    Jiang, Bin-hui; Zhao, Yan; Zhao, Xin; Hu, Xiao-min; Li, Li

    2015-01-01

    With the rapid industrial development, wastewater has been a risk for environmental contamination. We aimed to explore the optimum condition and mechanism of Pb2+ bio-sorption onto Rhodotorula mucilaginosa WT6-5. Optimization of initial concentration of Pb2+, initial pH, and adsorption time for Pb2+ bio-sorption onto R. mucilaginosa WT6-5 was performed using response surface methodology. Field emission scanning electron microscopy, energy dispersive X-ray detection, X-ray fluorescence and Fourier transform infrared spectroscopy were used to analyze the mechanisms and characteristics of Pb2+ bio-sorption. A maximum Pb2+ bio-sorption capacity of 1.45 mg/g was obtained under the optimal conditions of initial concentration of Pb2+ (30 mg/L), initial pH (5.45) and adsorption time (25 minutes). Some Pb2+ remained after adsorption, and the -OH, -C=O and C-O functional groups were primarily involved in Pb2+ bio-sorption onto R. mucilaginosa WT6-5. The mechanism of Pb2+ bio-sorption involved chemical and biological actions, ion exchange and functional groups effects.

  6. Optimization of hydrogel containing toluidine blue O for photodynamic therapy by response surface methodology.

    Science.gov (United States)

    Liang, Hui; Xu, Jialin; Liu, Yunfeng; Zhang, Jianxing; Peng, Wei; Yan, Jinhua; Li, Zelin; Li, Qingyong

    2017-08-01

    Photodynamic therapy with toluidine blue O (TBO) hydrogel exhibits antibacterial activity against Staphylococcus aureus and Escherichia coli in this paper. The response surface methodology is employed to optimize formulations for antibacterial activity. The optimal formulations are carbomer concentration of 3% (w/v), TBO concentration of 0.1mg/mL and the quality ratio of NaOH and carbomer of 0.4 (w/w). Under the optimized formulations, the log-transformed of CFUmL -1 on the Staphylococcus aureus and Escherichia coli are 0.84 and 1.26 (the log-transformed of CFUmL -1 of negative control groups on the Staphylococcus aureus and Escherichia coli are 8.21 and 8.47), respectively. In comparison with photodynamic therapy with TBO aqueous solution, the proposed formulations provide a much stronger antibacterial activity against Staphylococcus aureus and Escherichia coli. TBO hydrogels are stable during 6weeks at three different temperatures (4, 25 and 40°C) with respect to no change of color, transparency, pH and viscosity. 50% and 68.26% of TBO are released from carbomer hydrogel after 4h and 24h, respectively. TBO hydrogel alone or light alone (630nm) treatment is incapable of showing antibacterial activity against Staphylococcus aureus and Escherichia coli. Therefore, photodynamic therapy with the novel optimized TBO hydrogel formulations is a promising treatment strategy for periodontitis. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Protein hydrolysate from turkey meat and optimization of its antioxidant potential by response surface methodology.

    Science.gov (United States)

    Wang, Daoying; Shahidi, Fereidoon

    2018-05-01

    The objective of this research was to optimize antioxidant potential of hydrolyzed protein using Flavourzyme assisted hydrolysis of turkey meat and compare the antioxidant activity of hydrolysates from turkey meat, chicken, and beef. Response surface methodology (RSM) was used to determine the optimal Flavourzyme hydrolysis conditions for preparation of hydrolysate from turkey meat, which were at a temperature of 50.09°C, pH of 5.42, and processing time of 1.08 hours. For comparison, antioxidant activities of the hydrolysate from turkey meat, chicken, and beef under the optimum conditions were determined using reducing power, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical cation, hydroxyl radical, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. The antioxidant activity of turkey meat and chicken meat was significantly higher than that of beef (P turkey meat, indicating the potential use of it as a functional food ingredient with shelf-life extension purposes.

  8. Response surface methodology for autolysis parameters optimization of shrimp head and amino acids released during autolysis.

    Science.gov (United States)

    Cao, Wenhong; Zhang, Chaohua; Hong, Pengzhi; Ji, Hongwu

    2008-07-01

    Protein hydrolysates were prepared from the head waste of Penaens vannamei, a China seawater major shrimp by autolysis method. Autolysis conditions (viz., temperature, pH and substrate concentration) for preparing protein hydrolysates from the head waste proteins were optimized by response surface methodology (RSM) using a central composite design. Model equation was proposed with regard to the effect of temperature, pH and substrate concentration. Substrate concentration at 23% (w/v), pH at 7.85 and temperature at 50°C were found to be the optimal conditions to obtain a higher degree of hydrolysis close to 45%. The autolysis reaction was nearly finished in the initial 3h. The amino acid compositions of the autolysis hydrolysates prepared using the optimized conditions in different time revealed that the hydrolysates can be used as a functional food ingredient or flavor enhancer. Endogenous enzymes in the shrimp heads had a strong autolysis capacity (AC) for releasing threonine, serine, valine, isoleucine, tyrosine, histidine and tryptophan. Endogenous enzymes had a relatively lower AC for releasing cystine and glycine. Copyright © 2008. Published by Elsevier Ltd.

  9. Application of Response Surface Methodology for the Technological Improvement of Solid Lipid Nanoparticles.

    Science.gov (United States)

    Dal Pizzol, Carine; O'Reilly, Andre; Winter, Evelyn; Sonaglio, Diva; de Campos, Angela Machado; Creczynski-Pasa, Tânia Beatriz

    2016-02-01

    Solid lipid nanoparticles (SLN) are colloidal particles consisting of a matrix composed of solid (at room and body temperatures) lipids dispersed in aqueous emulsifier solution. During manufacture, their physicochemical properties may be affected by several formulation parameters, such as type and concentration of lipid, proportion of emulsifiers and amount of solvent. Thus, the aim of this work was to study the influence of these variables on the preparation of SLN. A D-optimal Response Surface Methodology design was used to establish a mathematical model for the optimization of SLN. A total of 30 SLN formulations were prepared using the ultrasound method, and then characterized on the basis of their physicochemical properties, including particle size, polydispersity index (PI) and Zeta Potential (s). Particle sizes ranged between 107 and 240 nm. All SLN formulations showed negative sigma and PI values below 0.28. Prediction of the optimal conditions was performed using the desirability function targeting the reduction of all responses. The optimized SLN formulation showed similar theoretical and experimental values, confirming the sturdiness and predictive ability of the mathematical model for SLN optimization.

  10. Development of flaxseed fortified rice - corn flour blend based extruded product by response surface methodology.

    Science.gov (United States)

    Ganorkar, P M; Jain, R K

    2015-08-01

    Flaxseed imparted the evidence of health benefits in human being. Response surface methodology (RSM) was employed to develop flaxseed fortified rice - corn flour blend based extruded product using twin screw extruder. The effect of roasted flaxseed flour (RFF) fortification (15-25 %), moisture content of feed (12-16 %, wb), extruder barrel temperature (120-140 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), bulk density (BD) and overall acceptability (OAA) score of extrudates were investigated using central composite rotatable design (CCRD). Increased RFF level decreased the ER and OAA score significantly while increased BS and BD of extrudates (p flour, 16 % moisture content (wb) of extruder feed, 120 °C extruder barrel temperature and 330 RPM of screw speed gave an optimized product of high desirability with corresponding responses as 3.08 ER, 0.53 kgf BS, 0.106 g.cm(-3) BD and 7.86 OAA.

  11. Optimization of keratinase production and enzyme activity using response surface methodology with Streptomyces sp7.

    Science.gov (United States)

    Tatineni, Radhika; Doddapaneni, Kiran Kumar; Potumarthi, Ravi Chandra; Mangamoori, Lakshmi Narasu

    2007-01-01

    A two-step response surface methodology (RSM) study was conducted for the optimization of keratinase production and enzyme activity from poultry feather by Streptomyces sp7. Initially different combinations of salts were screened for maximal production of keratinase at a constant pH of 6.5 and feather meal concentration of 5 g/L. A combination of K2HPO4, KH2PO4, and NaCl gave a maximum yield of keratinase (70.9 U/mL) production. In the first step of the RSM study, the selected five variables (feather meal, K2HPO4, KH2PO4, NaCl, and pH) were optimized by a 25 full-factorial rotatable central composite design (CCD) that resulted in 95 U/mL of keratinase production. The results of analysis of variance and regression of a second-order model showed that the linear effects of feather meal concentration (pNaCl (penzyme activity. These optima were pH 11.0, 45 degrees C, and 300 rpm.

  12. Esterification Optimization of Crude African Palm Olein Using Response Surface Methodology and Heterogeneous Acid Catalysis

    Directory of Open Access Journals (Sweden)

    Francisco Anguebes-Franseschi

    2018-01-01

    Full Text Available In this work, the effect of zeolite montmorillonite KSF in the esterification of free fatty acids (FFAs of crude African palm olein (Eleaias guinnesis Jacq was studied. To optimize the esterification of FFAs of the crude African palm olein (CAPO, the response surface methodology (RSM that was based on a central composite rotatable design (CCRD was used. The effects of three parameters were investigated: (a catalyst loading (2.6–9.4 wt %, (b reaction temperature (133.2–166.2 °C, and (c reaction time (0.32–3.68 h. The Analysis of variance (ANOVA indicated that linear terms of catalyst loading (X1, reaction temperature (X2, the quadratic term of catalyst loading ( X 1 2 , temperature reaction ( X 2 2 , reaction time ( X 3 2 , the interaction catalyst loading with reaction time ( X 1 * X3, and the interaction reaction temperature with reaction time ( X 2 * X3 have a significant effect (p < 0.05 with a 95% confidence level on Fatty Methyl Ester (FAME yield. The result indicated that the optimum reaction conditions to esterification of FFAs were: catalyst loading 9.4 wt %, reaction temperature 155.5 °C, and 3.3 h for reaction time, respectively. Under these conditions, the numerical estimation of FAME yield was 91.81 wt %. This result was experimentally validated obtaining a difference of 1.7% FAME yield, with respect to simulated values.

  13. Inulin blend as prebiotic and fat replacer in dairy desserts: optimization by response surface methodology.

    Science.gov (United States)

    Arcia, P L; Costell, E; Tárrega, A

    2011-05-01

    The purpose of this work was to optimize the formulation of a prebiotic dairy dessert with low fat content (<0.1g/100g) using a mixture of short- and long-chain inulin. Response surface methodology was applied to obtain the experimental design and data analysis. Nineteen formulations of dairy dessert were prepared, varying inulin concentration (3 to 9 g/100g), sucrose concentration (4 to 16 g/100g), and lemon flavor concentration (25 to 225 mg/kg). Sample acceptability evaluated by 100 consumers varied mainly in terms of inulin and sucrose concentrations and, to a lesser extent, of lemon flavor content. An interaction effect among inulin and sucrose concentration was also found. According to the model obtained, the formulation with 5.5 g/100g inulin, 10 g/100g sucrose and 60 mg/kg of lemon flavor was selected. Finally, this sample was compared sensorially with the regular fat content (2.8 g/100g) sample previously optimized in terms of lemon flavor (146 mg/kg) and sucrose (11.4 g/100g). No significant difference in acceptability was found between them but the low-fat sample with inulin possessed stronger lemon flavor and greater thickness and creaminess. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Istadi Istadi

    2009-06-01

    Full Text Available Biodiesel production has received considerable attention in the recent past as a renewable fuel. The production of biodiesel by conventional transesterification process employs alkali or acid catalyst and has been industrially accepted for its high conversion and reaction rates. However for alkali catalyst, there may be risk of free acid or water contamination and soap formation is likely to take place which makes the separation process difficult. Although yield is high, the acids, being corrosive, may cause damage to the equipment and the reaction rate was also observed to be low. This research focuses on empirical modeling and optimization for the biodiesel production over plasma reactor. The plasma reactor technology is more promising than the conventional catalytic processes due to the reducing reaction time and easy in product separation. Copyright (c 2009 by BCREC. All Rights reserved.[Received: 10 August 2009, Revised: 5 September 2009, Accepted: 12 October 2009][How to Cite: I. Istadi, D.D. Anggoro, P. Marwoto, S. Suherman, B.T. Nugroho (2009. Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology. Bulletin of Chemical Reaction Engineering and Catalysis, 4(1: 23-31.  doi:10.9767/bcrec.4.1.7115.23-31][How to Link/ DOI: http://dx.doi.org/10.9767/bcrec.4.1.7115.23-31 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/7115

  15. Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Bambang Tri Nugroho

    2009-06-01

    Full Text Available Biodiesel production has received considerable attention in the recent past as a renewable fuel. The production of biodiesel by conventional transesterification process employs alkali or acid catalyst and has been industrially accepted for its high conversion and reaction rates. However for alkali catalyst, there may be risk of free acid or water contamination and soap formation is likely to take place which makes the separation process difficult. Although yield is high, the acids, being corrosive, may cause damage to the equipment and the reaction rate was also observed to be low. This research focuses on empirical modeling and optimization for the biodiesel production over plasma reactor. The plasma reactor technology is more promising than the conventional catalytic processes due to the reducing reaction time and easy in product separation. Copyright (c 2009 by BCREC. All Rights reserved.[Received: 10 August 2009, Revised: 5 September 2009, Accepted: 12 October 2009][How to Cite: I. Istadi, D.D. Anggoro, P. Marwoto, S. Suherman, B.T. Nugroho (2009. Biodiesel Production from Vegetable Oil over Plasma Reactor: Optimization of Biodiesel Yield using Response Surface Methodology. Bulletin of Chemical Reaction Engineering and Catalysis, 4(1: 23-31. doi:10.9767/bcrec.4.1.23.23-31][How to Link/ DOI: http://dx.doi.org/10.9767/bcrec.4.1.23.23-31

  16. Response surface methodology optimization of nickel (II) removal using pigeon pea pod bio sorbent

    International Nuclear Information System (INIS)

    Aravind, J.; Lenin, C.; Nancyflavia, C.; Rashika, P.; Saravanan, S.

    2015-01-01

    Pod of pigeon pea (Cajanus cajan), a cellulose rich agricultural residue, was investigated for its nickel binding efficiency. The influence of key physicochemical parameters such as contact time, initial metal ion concentration, adsorbent dosage and p H on nickel (II) removal was studied. The equilibrium time was found to be 45 min. The optimum Ni (II) removal was obtained at an initial metal ion concentration of 80 mg/l, p H of 9.0 and an adsorbent dose of 400 mg/100 ml. A search for optimal combination of key variables was studied by response surface methodology for maximum removal of nickel. The experiment encompassing 17 runs was established with the aid of Box–Behnken design. Owing to the reasonable agreement between predicted and adjusted R2 value (0.9714), the corresponding quadratic model gives the most appropriate relationship between the variables and response. The optimal point obtained was located in the valid region and the optimum adsorption parameters were predicted as an initial Ni (II) concentration of 60 mg/l, p H value of 9.0 and contact time of 75 min. Under these adsorption conditions, a maximum removal of 96.54 % of initial metal concentration was demonstrated.

  17. Antioxidant activity of polysaccharide extracted from Pleurotus eryngii using response surface methodology.

    Science.gov (United States)

    Zhang, Anqiang; Li, Xueqing; Xing, Chen; Yang, Junhong; Sun, Peilong

    2014-04-01

    Ultrasonic technology was applied for polysaccharide extraction from the fruiting bodies of P. Eryngii, and response surface methodology (RSM) was used to optimize the effects of processing parameters on polysaccharide extraction yield. Three independent variables were extraction time (A), ultrasonic power (B) and the ratio of solvent to sample (C), respectively. Results showed that the maximum yield of P. eryngii polysaccharide (PEPS) was obtained at an optimum condition: extraction time 39 min, ultrasonic power 517 W, the ratio of water to material 19 mL/g, and the PEPS extracting yield reached 34.3% under the conditions. PEPS were precipitated into three crude polysaccharides, PEPS30, PEPS60 and PEPS80, by different concentrations of ethanol respectively. The antioxidant activities of these three polysaccharides were evaluated. The results showed that PEPS80 had the best reducing power, DPPH radical scavenging ability and oxygen radical scavenging ability followed by PEPS60 and PEPS30. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Optimization of lipase-catalyzed transesterification of lard for biodiesel production using response surface methodology.

    Science.gov (United States)

    Huang, Ying; Zheng, Hai; Yan, Yunjun

    2010-01-01

    Biodiesel, an alternative diesel fuel made from renewable biological resources, has become more and more attractive recently. Combined use of two immobilized lipases with complementary position specificity instead of one lipase is a potential way to significantly reduce cost of lipase-catalyzed biodiesel production. In this study, the process of biodiesel production from lard catalyzed by the combined use of Novozym435 (non-specific) and Lipozyme TLIM (1,3-specific) was optimized by response surface methodology. The optimal reaction conditions were 0.04 of amount of lipase/oil (w/w), 0.49 of proportion of Novozym435/total lipases (w/w), 0.55 of quantity of tert-butanol/oil (v/v), 5.12 of quantity of methanol/oil (mol/mol), and 20 h of reaction time, by which 97.2% of methyl ester (ME) yield was attained, very close to the predicted value (97.6%). This optimal reaction condition could be true of other similar reactions with plant and animal oil resources; their ME yield could be higher than 95%. The lipases regenerated by washing with organic solvent after each reaction cycle could be continuously reused for 20 cycles without any loss of activity, exhibiting very high manipulation stability.

  19. Methodologies for Removing/Desorbing and Transporting Particles from Surfaces to Instrumentation

    Science.gov (United States)

    Miller, Carla J.; Cespedes, Ernesto R.

    2012-12-01

    Explosive trace detection (ETD) continues to be a key technology supporting the fight against terrorist bombing threats. Very selective and sensitive ETD instruments have been developed to detect explosive threats concealed on personnel, in vehicles, in luggage, and in cargo containers, as well as for forensic analysis (e.g. post blast inspection, bomb-maker identification, etc.) in a broad range of homeland security, law enforcement, and military applications. A number of recent studies have highlighted the fact that significant improvements in ETD systems' capabilities will be achieved, not by increasing the selectivity/sensitivity of the sensors, but by improved techniques for particle/vapor sampling, pre-concentration, and transport to the sensors. This review article represents a compilation of studies focused on characterizing the adhesive properties of explosive particles, the methodologies for removing/desorbing these particles from a range of surfaces, and approaches for transporting them to the instrument. The objectives of this review are to summarize fundamental work in explosive particle characterization, to describe experimental work performed in harvesting and transport of these particles, and to highlight those approaches that indicate high potential for improving ETD capabilities.

  20. Extraction optimization of mucilage from Basil (Ocimum basilicumL.) seeds using response surface methodology.

    Science.gov (United States)

    Nazir, Sadaf; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad

    2017-05-01

    Aqueous extraction of basil seed mucilage was optimized using response surface methodology. A Central Composite Rotatable Design (CCRD) for modeling of three independent variables: temperature (40-91 °C); extraction time (1.6-3.3 h) and water/seed ratio (18:1-77:1) was used to study the response for yield. Experimental values for extraction yield ranged from 7.86 to 20.5 g/100 g. Extraction yield was significantly ( P  ratio were found to have pronounced effect while the extraction time was found to have minor possible effects. Graphical optimization determined the optimal conditions for the extraction of mucilage. The optimal condition predicted an extraction yield of 20.49 g/100 g at 56.7 °C, 1.6 h, and a water/seed ratio of 66.84:1. Optimal conditions were determined to obtain highest extraction yield. Results indicated that water/seed ratio was the most significant parameter, followed by temperature and time.

  1. [Extraction Optimization of Rhizome of Curcuma longa by Response Surface Methodology and Support Vector Regression].

    Science.gov (United States)

    Zhou, Pei-pei; Shan, Jin-feng; Jiang, Jian-lan

    2015-12-01

    To optimize the optimal microwave-assisted extraction method of curcuminoids from Curcuma longa. On the base of single factor experiment, the ethanol concentration, the ratio of liquid to solid and the microwave time were selected for further optimization. Support Vector Regression (SVR) and Central Composite Design-Response Surface Methodology (CCD) algorithm were utilized to design and establish models respectively, while Particle Swarm Optimization (PSO) was introduced to optimize the parameters of SVR models and to search optimal points of models. The evaluation indicator, the sum of curcumin, demethoxycurcumin and bisdemethoxycurcumin by HPLC, were used. The optimal parameters of microwave-assisted extraction were as follows: ethanol concentration of 69%, ratio of liquid to solid of 21 : 1, microwave time of 55 s. On those conditions, the sum of three curcuminoids was 28.97 mg/g (per gram of rhizomes powder). Both the CCD model and the SVR model were credible, for they have predicted the similar process condition and the deviation of yield were less than 1.2%.

  2. Optimization of mucilage extraction from chia seeds (Salvia hispanica L) using response surface methodology.

    Science.gov (United States)

    Orifici, Stefania C; Capitani, Marianela I; Tomás, Mabel C; Nolasco, Susana M

    2018-02-25

    Chia mucilage has potential application as a functional ingredient, advances on maximizing its extraction yield could represent a significant technological and economic impact for the food industry. Thus, firstly, the effect of mechanical agitation time (1-3 h) on the exudation of chia mucilage was analyzed. Then, response surface methodology was used to determine the optimal combination of the independent variables temperature (15-85 °C) and seed:water ratio (1:12-1:40.8 wt/v) for the 2 h exudation, that give maximum chia mucilage yield. Experiments were designed according to Central Composite Rotatable Design. A second-order polynomial model predicted the variation in extraction mucilage yield with the variables temperature and seed to water ratio. The optimal operating conditions were found to be temperature 85 °C and a seed:water ratio of 1:31 (wt/v), reaching an experimental extraction yield of 116 ± 0.21 g kg -1 d.b. The mucilage obtained exhibited good functional properties, mainly in terms of water-holding capacity, emulsifying activity and emulsion stability. The results obtained show that temperature, seed:water ratio and exudation time are important variables of the process that affect the extraction yield and the quality of the chia mucilage, determined according to its physicochemical and functional properties. This article is protected by copyright. All rights reserved.

  3. Optimization of fermentative biohydrogen production by response surface methodology using fresh leachate as nutrient supplement.

    Science.gov (United States)

    Liu, Qiang; Zhang, Xiaolei; Zhou, Yinmei; Zhao, Aihua; Chen, Shanping; Qian, Guangren; Xu, Zhi Ping

    2011-09-01

    Fresh compost leachate was used as a nutrients source to facilitate anaerobic fermentative hydrogen production from glucose inoculated with mixed culture. The optimum condition for hydrogen production was predicted by response surface methodology (RSM). The model showed the maximum cumulative hydrogen volume (469.74 mL) and molar hydrogen yield (1.60 mol H2/mol glucose) could be achieved at 6174.93 mg/L glucose and 3383.20 mg COD/L leachate. According to the predicted optimal condition, four tests were carried out to validate the predicted values and evaluate the leachate's effect on co-fermentation with juice wastewater. A maximum cumulative hydrogen volume of 587.05 ± 15.08 mL was obtained in co-fermentation test, and the molar hydrogen yield reached 2.06 ± 0.06 mol H2/mol glucose. The co-fermentation of fresh leachate and glucose/juice wastewater was a combination of acetic acid and butyric acid type-fermentation. The results demonstrated that leachate can serve as a nutrients source for biohydrogen production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Optimization of biodiesel production from castor oil using response surface methodology.

    Science.gov (United States)

    Jeong, Gwi-Taek; Park, Don-Hee

    2009-05-01

    The short supply of edible vegetable oils is the limiting factor in the progression of biodiesel technology; thus, in this study, we applied response surface methodology in order to optimize the reaction factors for biodiesel synthesis from inedible castor oil. Specifically, we evaluated the effects of multiple parameters and their reciprocal interactions using a five-level three-factor design. In a total of 20 individual experiments, we optimized the reaction temperature, oil-to-methanol molar ratio, and quantity of catalyst. Our model equation predicted that the following conditions would generate the maximum quantity of castor biodiesel (92 wt.%): a 40-min reaction at 35.5 degrees C, with an oil-to-methanol molar ratio of 1:8.24, and a catalyst concentration of 1.45% of KOH by weight of castor oil. Subsequent empirical analyses of the biodiesel generated under the predicted conditions showed that the model equation accurately predicted castor biodiesel yields within the tested ranges. The biodiesel produced from castor oil satisfied the relevant quality standards without regard to viscosity and cold filter plugging point.

  5. Optimization and Modeling of Process Variables of Biodiesel Production from Marula Oil using Response Surface Methodology

    International Nuclear Information System (INIS)

    Enweremadu, C. C.; Rutto, H. L.

    2015-01-01

    This paper presents an optimization study in the production of biodiesel production from Marula oil. The study was carried out using a central composite design of experiments under response surface methodology. A mathematical model was developed to correlate the transesterification process variables to biodiesel yield. The transesterification reaction variables were methanol to oil ratio, x /sub 1/ (10-50 wt percentage), reaction time, x /sub 2/ (30-90 min), reaction temperature, x /sub 3/ (30-90 Degree C) stirring speed, x /sub 4/ (100-400 rpm) and amount of catalyst, x /sub 5/ (0.5-1.5 g). The optimum conditions for the production of the biodiesel were found to be methanol to oil ratio (29.43 wt percentage), reaction time (59.17 minutes), reaction temperature (58.80 Degree C), stirring speed (325 rpm) and amount of catalyst (1.02 g). The optimum yield of biodiesel that can be produced was 95 percentage. The results revealed that the crucial fuel properties of the biodiesel produced at the optimum conditions met the ASTM biodiesel specifications. (author)

  6. Efficient harvesting of marine Chlorella vulgaris microalgae utilizing cationic starch nanoparticles by response surface methodology.

    Science.gov (United States)

    Bayat Tork, Mahya; Khalilzadeh, Rasoul; Kouchakzadeh, Hasan

    2017-11-01

    Harvesting involves nearly thirty percent of total production cost of microalgae that needs to be done efficiently. Utilizing inexpensive and highly available biopolymer-based flocculants can be a solution for reducing the harvest costs. Herein, flocculation process of Chlorella vulgaris microalgae using cationic starch nanoparticles (CSNPs) was evaluated and optimized through the response surface methodology (RSM). pH, microalgae and CSNPs concentrations were considered as the main independent variables. Under the optimum conditions of microalgae concentration 0.75gdry weight/L, CSNPs concentration 7.1mgdry weight/L and pH 11.8, the maximum flocculation efficiency (90%) achieved. Twenty percent increase in flocculation efficiency observed with the use of CSNPs instead of the non-particulate starch which can be due to the more electrostatic interactions between the cationic nanoparticles and the microalgae. Therefore, the synthesized CSNPs can be employed as a convenient and economical flocculants for efficient harvest of Chlorella vulgaris microalgae at large scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Optimization of the extraction of carrageenan from Kappaphycus alvarezii using response surface methodology

    Directory of Open Access Journals (Sweden)

    Vanessa Webber

    2012-12-01

    Full Text Available This study aims to optimize an alternative method of extraction of carrageenan without previous alkaline treatment and ethanol precipitation using Response Surface Methodology (RSM. In order to introduce an innovation in the isolation step, atomization drying was used reducing the time for obtaining dry carrageenan powder. The effects of extraction time and temperature on yield, gel strength, and viscosity were evaluated. Furthermore, the extracted material was submitted to structural analysis, by infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H-NMR, and chemical composition analysis. Results showed that the generated regression models adequately explained the data variation. Carrageenan yield and gel viscosity were influenced only by the extraction temperature. However, gel strength was influenced by both, extraction time and extraction temperature. Optimal extraction conditions were 74 ºC and 4 hours. In these conditions, the carrageenan extract properties determined by the polynomial model were 31.17%, 158.27 g.cm-2, and 29.5 cP for yield, gel strength, and viscosity, respectively, while under the experimental conditions they were 35.8 ± 4.68%, 112.50 ± 4.96 g.cm-2, and 16.01 ± 1.03 cP, respectively. The chemical composition, nuclear magnetic resonance spectroscopy, and infrared spectroscopy analyses showed that the crude carrageenan extracted is composed mainly of κ-carrageenan.

  8. Optimizations of α-amylase production by response surface methodology in immobilization Bacillus amyloliquefaciens ATCC 23350

    Directory of Open Access Journals (Sweden)

    Hamid reza Samadlouie

    2016-03-01

    Full Text Available Introduction: Production of an endogenous α-amylase from Bacillus amyloliquefaciens ATCC 23350 was studied and enhanced. Materials and methods: Protein and carbon sources were analyzed for free and immobilized bacterial cells and number of beads was considered for immobilized cells via one factor at a time methodforα-amylase production by Bacillus amyloliquefaciens. Subsequently, optimization condition was employed solely for immobilized bacterial cells by response surface methodology (RSM. Results: Peptone and rice starch showed to improve the α-amylase production in immobilized Bacillus cells. RSM generated a mathematical model explaining the optimum concentration of the efficient nutrients (139.35 g/l of rice starch and 80.00 g/l of peptone leading to an optimum amylase production (205 U/ml. Discussion and conclusion: The statistical advance displayed significant outcomes to optimize the process parameters for maximal α-amylase production using Bacillus amyloliquefaciens and gave permission to rapid screening of variables. RSM led to find out an immense improvement in enzyme activity (more than 90%: from 25 to 225 U/ml for the first time. 

  9. Removal of fluoride from aqueous solution by adsorption on hydroxyapatite (HAp using response surface methodology

    Directory of Open Access Journals (Sweden)

    M. Mourabet

    2015-11-01

    Full Text Available A study on the adsorption of fluoride onto hydroxyapatite was conducted and the process parameters were optimized using Response Surface Methodology (RSM. Hydroxyapatite has been characterized by using different physicochemical methods. In order to determine the effects of process parameters namely temperature (20–40 °C, initial solution pH (4–11, adsorbent dose (0.1–0.3 g and initial fluoride concentration (10–20 mg L−1 on fluoride uptake from aqueous solution, a three-level, four-factor, Box–Behnken design has been employed. The second order mathematical model was developed by regression analysis of the experimental data obtained from 29 batch runs. The optimum pH, temperature, adsorbent dose and initial concentration were found by desirability function to be 4.16, 39.02 °C, 0.28 g and 20 mg L−1, respectively. Fluoride removal was 86.34% at the optimum combination of process parameters. Dynamic adsorption data were applied to pseudo-first-order and pseudo-second-order rate equations. The time data fitted well to pseudo second order kinetic model. According to the correlation coefficients, the adsorption of fluoride on the hydroxyapatite was correlated well with the Langmuir and Freundlich models.

  10. Optimization of Fat-Reduced Puff Pastry Using Response Surface Methodology.

    Science.gov (United States)

    Silow, Christoph; Zannini, Emanuele; Axel, Claudia; Belz, Markus C E; Arendt, Elke K

    2017-02-22

    Puff pastry is a high-fat bakery product with fat playing a key role, both during the production process and in the final pastry. In this study, response surface methodology (RSM) was successfully used to evaluate puff pastry quality for the development of a fat-reduced version. The technological parameters modified included the level of roll-in fat, the number of fat layers (50-200) and the final thickness (1.0-3.5 mm) of the laminated dough. Quality characteristics of puff pastry were measured using the Texture Analyzer with an attached Extended Craft Knife (ECK) and Multiple Puncture Probe (MPP), the VolScan and the C-Cell imaging system. The number of fat layers and final dough thickness, in combination with the amount of roll-in fat, had a significant impact on the internal and external structural quality parameters. With technological changes alone, a fat-reduced (≥30%) puff pastry was developed. The qualities of fat-reduced puff pastries were comparable to conventional full-fat (33 wt %) products. A sensory acceptance test revealed no significant differences in taste of fatness or 'liking of mouthfeel'. Additionally, the fat-reduced puff pastry resulted in a significant ( p < 0.05) positive correlation to 'liking of flavor' and overall acceptance by the assessors.

  11. Optimization of Fat-Reduced Puff Pastry Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Christoph Silow

    2017-02-01

    Full Text Available Puff pastry is a high-fat bakery product with fat playing a key role, both during the production process and in the final pastry. In this study, response surface methodology (RSM was successfully used to evaluate puff pastry quality for the development of a fat-reduced version. The technological parameters modified included the level of roll-in fat, the number of fat layers (50–200 and the final thickness (1.0–3.5 mm of the laminated dough. Quality characteristics of puff pastry were measured using the Texture Analyzer with an attached Extended Craft Knife (ECK and Multiple Puncture Probe (MPP, the VolScan and the C-Cell imaging system. The number of fat layers and final dough thickness, in combination with the amount of roll-in fat, had a significant impact on the internal and external structural quality parameters. With technological changes alone, a fat-reduced (≥30% puff pastry was developed. The qualities of fat-reduced puff pastries were comparable to conventional full-fat (33 wt % products. A sensory acceptance test revealed no significant differences in taste of fatness or ‘liking of mouthfeel’. Additionally, the fat-reduced puff pastry resulted in a significant (p < 0.05 positive correlation to ‘liking of flavor’ and overall acceptance by the assessors.

  12. Recycling process of spent bleaching clay: Optimization by response surface methodology

    Directory of Open Access Journals (Sweden)

    A.M. Hatami

    2018-01-01

    Full Text Available Oil refining is an inevitable step in production of edible and industrial oil. Bleaching is the most important process among the refining processes. Bleaching adsorption is the most common method and clay is the most widely used adsorbent in this method. Disposal of bleaching clay, as a waste from re-refining plants, makes many environmental problems and economic losses. In the current study, the effects of possible factors such as solvent to clay ratio, temperature, time, aggregation size and rotation speed of the stirrer (degree of mixing on the efficiency of extracted lubricating oil were investigated by solvent extraction method. By conducting experiments at different reaction times and rotation speeds, it was concluded that the most important factor in obtaining the appropriate output was solvent to clay ratio. The tests conducted to investigate the effect of grain size on the efficiency indicated that agglomerates size did not have a positive effect on efficiency. Finally, for the solvent to clay ratios ranging from 2.48-9.53 ml/g and a time period ranging from 5 to 40 minutes, the main tests designed by the response surface methodology. The best efficiency was obtained at the highest level of solvent to clay ratio (9.53 ml/g and at the time of 22.5 minutes that led to 88.60% oil extraction from the clay. The accuracy of the model output was estimated to be 96%.

  13. Optimization of ultrasound-assisted extraction of charantin from Momordica charantia fruits using response surface methodology.

    Science.gov (United States)

    Ahamad, Javed; Amin, Saima; Mir, Showkat R

    2015-01-01

    Momordica charantia Linn. (Cucurbitaceae) fruits are well known for their beneficial effects in diabetes that are often attributed to its bioactive component charantin. The aim of the present study is to develop and optimize an efficient protocol for the extraction of charantin from M. charantia fruits. Response surface methodology (RSM) was used for the optimization of ultrasound-assisted extraction (UAE) conditions. RSM was based on a three-level, three-variable Box-Behnken design (BBD), and the studied variables included solid to solvent ratio, extraction temperature, and extraction time. The optimal conditions predicted by the BBD were: UAE with methanol: Water (80:20, v/v) at 46°C for 120 min with solid to solvent ratio of 1:26 w/v, under which the yield of charantin was 3.18 mg/g. Confirmation trials under slightly adjusted conditions yielded 3.12 ± 0.14 mg/g of charantin on dry weight basis of fruits. The result of UAE was also compared with Soxhlet extraction method and UAE was found 2.74-fold more efficient than the Soxhlet extraction for extracting charantin. A facile UAE protocol for a high extraction yield of charantin was developed and validated.

  14. Response surface methodology to optimise Accelerated Solvent Extraction of steviol glycosides from Stevia rebaudiana Bertoni leaves.

    Science.gov (United States)

    Jentzer, Jean-Baptiste; Alignan, Marion; Vaca-Garcia, Carlos; Rigal, Luc; Vilarem, Gérard

    2015-01-01

    Following the approval of steviol glycosides as a food additive in Europe in December 2011, large-scale stevia cultivation will have to be developed within the EU. Thus there is a need to increase the efficiency of stevia evaluation through germplasm enhancement and agronomic improvement programs. To address the need for faster and reproducible sample throughput, conditions for automated extraction of dried stevia leaves using Accelerated Solvent Extraction were optimised. A response surface methodology was used to investigate the influence of three factors: extraction temperature, static time and cycle number on the stevioside and rebaudioside A extraction yields. The model showed that all the factors had an individual influence on the yield. Optimum extraction conditions were set at 100 °C, 4 min and 1 cycle, which yielded 91.8% ± 3.4% of total extractable steviol glycosides analysed. An additional optimisation was achieved by reducing the grind size of the leaves giving a final yield of 100.8% ± 3.3%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Investigating thiol-modification on hyaluronan via carbodiimide chemistry using response surface methodology.

    Science.gov (United States)

    Santhanam, Sruthi; Liang, Jue; Baid, Rinku; Ravi, Nathan

    2015-07-01

    Hyaluronan (HA) is a naturally occurring glycosaminoglycan widely researched for its use as a biomaterial in tissue engineering, drug delivery, angiogenesis, and ophthalmic surgeries. The mechanical properties of this biomaterial can be altered to a required extent by chemically modifying the pendant reactive groups. However, derivatizing these polymers to a predetermined extent has been the Achilles heel for this process. In this study, we have investigated the factors controlling the derivatization of the carboxyl moieties of HA with amine containing thiol, cystamine dihydrochloride (Cys), via carbodiimide crosslinking chemistry. We used fractional factorial design to screen and identify the significant factor(s) affecting the reaction, and response surface methodology (RSM) to develop a model equation for predicting the degree of thiolation of HA. Also, we analyzed the reaction mechanism for potential side reactions. We observed that N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) (mole ratio with repeat unit of HA) is the significant factor controlling the degree of amidation. The quadratic equations developed from RSM predict the formulation for a desired degree of amidation of HA and percentage of potential side product. Hence, derivatizing HA to a predetermined extent with minimal side product can be achieved using the statistical design of experiments. © 2014 Wiley Periodicals, Inc.

  16. Optimization of ultrasound-assisted extraction of charantin from Momordica charantia fruits using response surface methodology

    Directory of Open Access Journals (Sweden)

    Javed Ahamad

    2015-01-01

    Full Text Available Background: Momordica charantia Linn. (Cucurbitaceae fruits are well known for their beneficial effects in diabetes that are often attributed to its bioactive component charantin. Objective: The aim of the present study is to develop and optimize an efficient protocol for the extraction of charantin from M. charantia fruits. Materials and Methods: Response surface methodology (RSM was used for the optimization of ultrasound-assisted extraction (UAE conditions. RSM was based on a three-level, three-variable Box-Behnken design (BBD, and the studied variables included solid to solvent ratio, extraction temperature, and extraction time. Results: The optimal conditions predicted by the BBD were: UAE with methanol: Water (80:20, v/v at 46°C for 120 min with solid to solvent ratio of 1:26 w/v, under which the yield of charantin was 3.18 mg/g. Confirmation trials under slightly adjusted conditions yielded 3.12 ± 0.14 mg/g of charantin on dry weight basis of fruits. The result of UAE was also compared with Soxhlet extraction method and UAE was found 2.74-fold more efficient than the Soxhlet extraction for extracting charantin. Conclusions:A facile UAE protocol for a high extraction yield of charantin was developed and validated.

  17. Optimization of ultrasound-assisted extraction of charantin from Momordica charantia fruits using response surface methodology

    Science.gov (United States)

    Ahamad, Javed; Amin, Saima; Mir, Showkat R.

    2015-01-01

    Background: Momordica charantia Linn. (Cucurbitaceae) fruits are well known for their beneficial effects in diabetes that are often attributed to its bioactive component charantin. Objective: The aim of the present study is to develop and optimize an efficient protocol for the extraction of charantin from M. charantia fruits. Materials and Methods: Response surface methodology (RSM) was used for the optimization of ultrasound-assisted extraction (UAE) conditions. RSM was based on a three-level, three-variable Box-Behnken design (BBD), and the studied variables included solid to solvent ratio, extraction temperature, and extraction time. Results: The optimal conditions predicted by the BBD were: UAE with methanol: Water (80:20, v/v) at 46°C for 120 min with solid to solvent ratio of 1:26 w/v, under which the yield of charantin was 3.18 mg/g. Confirmation trials under slightly adjusted conditions yielded 3.12 ± 0.14 mg/g of charantin on dry weight basis of fruits. The result of UAE was also compared with Soxhlet extraction method and UAE was found 2.74-fold more efficient than the Soxhlet extraction for extracting charantin. Conclusions: A facile UAE protocol for a high extraction yield of charantin was developed and validated. PMID:26681889

  18. Optimization of Cyan flexo dye removal by nano zero-valent iron using response surface methodology

    Directory of Open Access Journals (Sweden)

    Vesna Kecić

    2017-12-01

    Full Text Available Application of nano zero-valent iron (nZVI as a catalyst in a decolorization process is a simple and sensitive method for Cyan flexo dye removal from the aqueous solution. In this paper, a central composite design (CCD, under the response surface methodology (RSM, was applied in order to optimize experimental conditions of the Cyan removal from aqueous solution. The influence of four independent variables was studied: nZVI dosage (5–45 mg L-1, initial dye concentration (2–14 g L-1, pH (2–10 and removal time (20–100 min, in order to build second order quadratic model and to predict the responses. The highest removal percent of 96.35% was attained, and the optimum parameters are achieved after 1h/24h precipitation: nZVI dosage (5/45 mg L-1, initial dye concentration (2/14 g L-1, removal time (20/100 min and pH (2/10. The Cyan removal efficiency of 38% and 62% were estimated under optimized experimental conditions.

  19. Application of response surface methodology to enhancement of biomass production by Lactobacillus rhamnosus E/N

    Directory of Open Access Journals (Sweden)

    Magdalena Polak-Berecka

    2011-12-01

    Full Text Available Response surface methodology (RSM was employed to study the effects of various medium components on biomass production by Lactobacillus rhamnosus E/N. This strain is commonly used in the pharmaceutical and food industries due to its beneficial effect on the human gut and general health. The best medium composition derived from RSM regression was (in g/l glucose 15.44, sodium pyruvate 3.92, meat extract 8.0, potassium phosphate 1.88, sodium acetate 4.7, and ammonium citrate 1.88. With this medium composition biomass production was 23 g/l of dry cell weight after 18 h of cultivation in bioreactor conditions, whereas on MRS the yield of biomass was 21 g/l of dry cell weight. The cost of 1 g of biomass obtained on MRS broth was calculated at the level of 0.44 € whereas on the new optimal medium it was 25% lower. It may be concluded then, that the new medium, being cheaper than the control MRS allows large scale commercial cultivation of the L. rhamnosus strain. This study is of relevance to food industry because the possibility to obtain high yield of bacterial biomass is necessary step in manufacturing of probiotic food.

  20. Study of the filtration performance of a plain wave fabric filter using response surface methodology.

    Science.gov (United States)

    Qian, Fuping; Wang, Haigang

    2010-04-15

    The gas-solid two-phase flows in the plain wave fabric filter were simulated by computational fluid dynamics (CFD) technology, and the warps and wefts of the fabric filter were made of filaments with different dimensions. The numerical solutions were carried out using commercial computational fluid dynamics (CFD) code Fluent 6.1. The filtration performances of the plain wave fabric filter with different geometry parameters and operating condition, including the horizontal distance, the vertical distance and the face velocity were calculated. The effects of geometry parameters and operating condition on filtration efficiency and pressure drop were studied using response surface methodology (RSM) by means of the statistical software (Minitab V14), and two second-order polynomial models were obtained with regard to the effect of the three factors as stated above. Moreover, the models were modified by dismissing the insignificant terms. The results show that the horizontal distance, vertical distance and the face velocity all play an important role in influencing the filtration efficiency and pressure drop of the plane wave fabric filters. The horizontal distance of 3.8 times the fiber diameter, the vertical distance of 4.0 times the fiber diameter and Reynolds number of 0.98 are found to be the optimal conditions to achieve the highest filtration efficiency at the same face velocity, while maintaining an acceptable pressure drop. 2009 Elsevier B.V. All rights reserved.

  1. Optimizing the Maximum Recovery of Dihydromyricetin from Chinese Vine Tea, Ampelopsis grossedentata, Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Umair Muhammad

    2017-12-01

    Full Text Available This work provides an optimized extraction approach intended to maximize the recovery of dihydromyricetin (DHM from Chinese vine tea (Ampelopsis grossedentata leaves. The presented work adopts a Box-Behnken design as a response surface methodology to understand the role and influence of specific extraction parameters including: time, temperature, and solvent composition/ethanol (% on DHM final yields. Initially, single factor experiments were used to delineate the role of above factors (temperature, time, and solvent composition before proceeding with three factors-three levels Box-Behnken design with 17 separate runs to assess the effect of multifactorial treatments on DHM recovery rates. The collected data shows that independent variables (solvent composition, time, and temperature can significantly affect DHM recovery rates with maximum yields resulting from a combined 60 °C, 60% aqueous ethanol, and 180 min treatment. From the empirical point of view, the above optimized extraction protocol can substantially enhance processing and profitability margins with a minimum need of interventions or associated costs.

  2. Microencapsulation of Theobroma cacao L. waste extract: optimization using response surface methodology.

    Science.gov (United States)

    Gabbay Alves, Taís Vanessa; Silva da Costa, Russany; Aliakbarian, Bahar; Casazza, Alessandro Alberto; Perego, Patrizia; Carréra Silva Júnior, José Otávio; Ribeiro Costa, Roseane Maria; Converti, Attilio

    2017-03-01

    The cocoa extract (Theobroma cacao L.) has a significant amount of polyphenols (TP) with potent antioxidant activity (AA). This study aims to optimise microencapsulation of the extract of cocoa waste using chitosan and maltodextrin. Microencapsulation tests were performed according to a Box-Behnken factorial design, and the results were evaluated by response surface methodology with temperature, maltodextrin concentration (MD) and extract flowrate (EF) as independent variables, and the fraction of encapsulated TP, TP encapsulation yield, AA, yield of drying and solubility index as responses. The optimum conditions were: inlet temperature of 170 °C, MD of 5% and EF of 2.5 mL/min. HPLC analysis identified epicatechin as the major component of both the extract and microparticles. TP release was faster at pH 3.5 than in water. These results as a whole suggest that microencapsulation was successful and the final product can be used as a nutrient source for aquatic animal feed. Highlights Microencapsulation is optimised according to a factorial design of the Box-Behnken type. Epicatechin is the major component of both the extract and microcapsules. The release of polyphenols from microcapsules is faster at pH 3.5 than in water.

  3. Process optimization of microencapsulation of curcumin in γ-polyglutamic acid using response surface methodology.

    Science.gov (United States)

    Ko, Wen-Ching; Chang, Chao-Kai; Wang, Hsiu-Ju; Wang, Shian-Jen; Hsieh, Chang-Wei

    2015-04-01

    The aim of this study was to develop an optimal microencapsulation method for an oil-soluble component (curcumin) using γ-PGA. The results show that Span80 significantly enhances the encapsulation efficiency (EE) of γ-Na(+)-PGA microcapsules. Therefore, the effects of γ-Na(+)-PGA, curcumin and Span80 concentration on EE of γ-Na(+)-PGA microcapsules were studied by means of response surface methodology (RSM). It was found that the optimal microencapsulation process is achieved by using γ-Na(+)-PGA 6.05%, curcumin 15.97% and Span80 0.61% with a high EE% (74.47 ± 0.20%). Furthermore, the models explain 98% of the variability in the responses. γ-Na(+)-PGA seems to be a good carrier for the encapsulation of curcumin. In conclusion, this simple and versatile approach can potentially be applied to the microencapsulation of various oil-soluble components for food applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Application of response surface methodology to optimize the extracellular fungal mediated nanosilver green synthesis

    Directory of Open Access Journals (Sweden)

    Abdelmageed M. Othman

    2017-12-01

    Full Text Available This study aims to optimize the biosynthesis of nanosilver particles mediated by Trichoderma viride ATCC36838 using response surface methodology (RSM. Silver nanoparticles (AgNPs were biosynthesized effectively in terms of the factors impacting silver ion (Ag+ reduction to metallic nanosilver (Ag0 using culture filtrate under shaking condition. The results of statistics calculations revealed that 2 mM silver nitrate and 28% (v/v of culture filtrate at pH 7.0 for 34 h were the optimum values for AgNPs biosynthesis. The characterization of the produced AgNPs was conducted using electron microscopy, energy dispersive X-ray analysis, UV/visible spectrophotometry, and Fourier transform infrared spectroscopy. Round to oval AgNPs were detected with aspects of TEM within diameter range of 4–16 nm. The results of this study could help in developing a reliable ecofriendly, simple, and low cost process for microbial assisted AgNPs green synthesis especially with the continuous increase in its application fields.

  5. Recent Progresses in Incorporating Human Land-Water Management into Global Land Surface Models Toward Their Integration into Earth System Models

    Science.gov (United States)

    Pokhrel, Yadu N.; Hanasaki, Naota; Wada, Yoshihide; Kim, Hyungjun

    2016-01-01

    The global water cycle has been profoundly affected by human land-water management. As the changes in the water cycle on land can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to represent human land-water management in Earth system models (ESMs). During the recent past, noteworthy progress has been made in large-scale modeling of human impacts on the water cycle but sufficient advancements have not yet been made in integrating the newly developed schemes into ESMs. This study reviews the progresses made in incorporating human factors in large-scale hydrological models and their integration into ESMs. The study focuses primarily on the recent advancements and existing challenges in incorporating human impacts in global land surface models (LSMs) as a way forward to the development of ESMs with humans as integral components, but a brief review of global hydrological models (GHMs) is also provided. The study begins with the general overview of human impacts on the water cycle. Then, the algorithms currently employed to represent irrigation, reservoir operation, and groundwater pumping are discussed. Next, methodological deficiencies in current modeling approaches and existing challenges are identified. Furthermore, light is shed on the sources of uncertainties associated with model parameterizations, grid resolution, and datasets used for forcing and validation. Finally, representing human land-water management in LSMs is highlighted as an important research direction toward developing integrated models using ESM frameworks for the holistic study of human-water interactions within the Earths system.

  6. Incorporating an Inert Polymer into the Interlayer Passivates Surface Defects in Methylammonium Lead Halide Perovskite Solar Cells.

    Science.gov (United States)

    Bi, Shiqing; Zhang, Xuning; Qin, Liang; Wang, Rong; Zhou, Jiyu; Leng, Xuanye; Qiu, Xiaohui; Zhang, Yuan; Zhou, Huiqiong; Tang, Zhiyong

    2017-10-17

    The hysteresis effect and instability are important concerns in hybrid perovskite photovoltaic devices that hold great promise in energy conversion applications. In this study, we show that the power conversion efficiency (PCE), hysteresis, and device lifetime can be simultaneously improved for methylammoniumlead halide (CH 3 NH 3 PbI 3-x Cl x ) solar cells after incorporating poly(methyl methacrylate) (PMMA) into the PC 61 BM electron extraction layer (EEL). By choosing appropriate molecular weights of PMMA, we obtain a 30 % enhancement of PCE along with effectively lowered hysteresis and device degradation, adopting inverted planar device structure. Through the combinatorial study using Kelvin probe force microscopy, diode mobility measurements, and irradiation-dependent solar cell characterization, we attribute the enhanced device parameters (fill factor and open circuit voltage) to the surface passivation of CH 3 NH 3 PbI 3-x Cl x , leading to mitigating charge trapping at the cathode interface and resultant Shockley-Read-Hall charge recombination. Beneficially, modified by inert PMMA, CH 3 NH 3 PbI 3-x Cl x solar cells display a pronounced retardation in performance degradation, resulting from improved film quality in the PC 61 BM layer incorporating PMMA which increases the protection for underneath perovskite films. This work enables a versatile and effective interface approach to deal with essential concerns for solution-processed perovskite solar cells by air-stable and widely accessible materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Optimizing the conditions for hydrothermal liquefaction of barley straw for bio-crude oil production using response surface methodology

    DEFF Research Database (Denmark)

    Zhu, Zhe; Rosendahl, Lasse Aistrup; Toor, Saqib Sohail

    2018-01-01

    The present paper examines the conversion of barley straw to bio-crude oil (BO) via hydrothermal liquefaction. Response surface methodology based on central composite design was utilized to optimize the conditions of four independent variables including reaction temperature (factor X1, 260-340 o...

  8. Introduction to the Design and Optimization of Experiments Using Response Surface Methodology. A Gas Chromatography Experiment for the Instrumentation Laboratory

    Science.gov (United States)

    Lang, Patricia L.; Miller, Benjamin I.; Nowak, Abigail Tuttle

    2006-01-01

    The study describes how to design and optimize an experiment with multiple factors and multiple responses. The experiment uses fractional factorial analysis as a screening experiment only to identify important instrumental factors and does not use response surface methodology to find the optimal set of conditions.

  9. Response surface methodology (RSM) to evaluate moisture effects on corn stover in recovering xylose by DEO hydrolysis

    Science.gov (United States)

    Rita C.L.B. Rodrigues; William R. Kenealy; Diane Dietrich; Thomas W. Jeffries

    2012-01-01

    Response surface methodology (RSM), based on a 22 full factorial design, evaluated the moisture effects in recovering xylose by diethyloxalate (DEO) hydrolysis. Experiments were carried out in laboratory reactors (10 mL glass ampoules) containing corn stover (0.5 g) properly ground. The ampoules were kept at 160 °C for 90 min. Both DEO...

  10. Optimization of a cryoprotective medium to increase the viability of freeze-dried Streptococcus thermophilus by response surface methodology

    Science.gov (United States)

    Streptococcus thermophilus normally exhibits different survival rates in different bacteria medium during freeze-drying. In this study, response surface methodology (RSM) was applied on the design of experiments for optimizing the cryoprotective medium. Results showed that the most significant facto...

  11. Optimization of hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology

    NARCIS (Netherlands)

    Chen, H.; Xu, X.; Zhu, Y.

    2010-01-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different

  12. Numerical thermal analysis and optimization of multi-chip LED module using response surface methodology and genetic algorithm

    NARCIS (Netherlands)

    Tang, Hong Yu; Ye, Huai Yu; Chen, Xian Ping; Qian, Cheng; Fan, Xue Jun; Zhang, G.Q.

    2017-01-01

    In this paper, the heat transfer performance of the multi-chip (MC) LED module is investigated numerically by using a general analytical solution. The configuration of the module is optimized with genetic algorithm (GA) combined with a response surface methodology. The space between chips, the

  13. Simultaneous effect of dissolved organic carbon, surfactant, and organic acid on the desorption of pesticides investigated by response surface methodology

    DEFF Research Database (Denmark)

    Trinh, Ha Thu; Duong, Hanh Thi; Ta, Thao Thi

    2017-01-01

    factorial design and the Box-Behnken response surface methodology (RSM). Five concentration levels of DOC (8 to 92 mg L(-1)), SDS (0 to 6.4 critical micelle concentration (CMC)), and Oxa (0 to 0.15 M) were used for the experiments with a rice field topsoil. The results of RSM analysis and analysis...

  14. Tool flank wear model and parametric optimization in end milling of metal matrix composite using carbide tool: Response surface methodology approach

    Directory of Open Access Journals (Sweden)

    R. Arokiadass

    2012-04-01

    Full Text Available Highly automated CNC end milling machines in manufacturing industry requires reliable model for prediction of tool flank wear. This model later can be used to predict the tool flank wear (VBmax according to the process parameters. In this investigation an attempt was made to develop an empirical relationship to predict the tool flank wear (VBmax of carbide tools while machining LM25 Al/SiCp incorporating the process parameters such as spindle speed (N, feed rate (f, depth of cut (d and various % wt. of silicon carbide (S. Response surface methodology (RSM was applied to optimizing the end milling process parameters to attain the minimum tool flank wear. Predicted values obtained from the developed model and experimental results are compared, and error <5 percent is observed. In addition, it is concluded that the flank wear increases with the increase of SiCp percentage weight in the MMC.

  15. Optimization of an A(2)/O process for tetracycline removal via response surface methodology coupled with a Box-Behnken design.

    Science.gov (United States)

    Qi, Fang-Fang; Huang, Man-Hong; Zheng, Yu; Xu, Qi

    2015-01-01

    Response surface methodology (RSM) was used to optimize the operating conditions of an anaerobic-anoxic-oxic (A(2)/O) process by maximizing the removal efficiency of tetracycline (TC). Solid retention time (SRT), hydraulic retention time (HRT) and initial TC concentration (CTC, in) were selected as independent variables for incorporation in the Box-Behnken design. The results showed SRT and CTC, in were more significant parameters than HRT for the removal efficiency of TC. TC could be completely removed under the optimal conditions of an SRT of 15.5 days, an HRT of 9.9 h and a CTC, in of 283.3 μg L(-1). TC removal efficiencies of 99% and 96% were attained for synthetic and real wastewater, respectively, under the optimal conditions. This indicated the constructed model was validated and reliable for optimizing the A(2)/O process for TC removal.

  16. Optimization of a Functional Cookie Formulation by Using Response Surface Methodology

    International Nuclear Information System (INIS)

    Lee, L.Y.; Tan, K.S.; Liew, S.L.

    2011-01-01

    A functional cookie formulation containing oligo fructose, dietary fibre and lower calorie, fat and sugar contents than conventional cookies was optimized using Response Surface Methodology (RSM). Instant N-Oil II was used as a fat replacer, while Raftilose P95 was used as a sugar substitute with the addition of fructose to enhance sweetness. Selection of the optimal formulation was based on caloric content. An optimized formulation, V1, was obtained from the model Y = 4927.70 - 152.34X 1 - 155.42X 3 + 104.20X 3 2 + 151.71X 3 3 - 95.08X 3 4 , where Instant N-Oil II replaced 30 % of butter and 24.4 %, w/w (30.5 g) fructose replaced 40.0 %, w/w (50.0 g) sucrose. Two additional optimized formulations, S1 and S2, were proposed which contained the same ingredients as V1, but both contained 19.0 %, w/w (23.8 g) Raftilose P95. Also, S2 had a higher fat replacement level (42 %). A reference cookie prepared from a conventional recipe received significantly higher scores (P < 0.05) than the functional cookies V1, S1 and S2 in the sensory evaluation. However, when health benefits of the functional cookies were explained to the panel after the sensory evaluation had concluded, majority of the panelists stated that they would prefer S1, had they known of its health benefits. S1 contained 19.04 % fat, 8.62 % fructose and 0.74 % sucrose, namely, significantly lower fat and sucrose levels and higher fructose content than the conventional cookie. (author)

  17. Optimization of Solid-Liquid Extraction of Antioxidants from Black Mulberry Leaves by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Zoran Zeković

    2012-01-01

    Full Text Available The extraction of active components from natural sources depends on different factors. The knowledge of the effects of different extraction parameters is useful for the optimization of the process, as well for the ability to predict the extraction yield. The aim of this study is to examine the influence of solvent concentration (ethanol/water 40–80 %, by volume, temperature (40–80 °C and solvent/raw material ratio (10–30 mL/g on the extraction yield of phenolic compounds, flavonoids and antioxidant activity from black mulberry (Morus nigra L. leaves. Experimental values of total phenolic content were in the range from 18.6 to 48.7 mg of chlorogenic acid equivalents per g of dried leaves and total flavonoids in the range from 6.0 to 21.4 mg of rutin eqivalents per g of dried leaves. Antioxidant activity expressed as the inhibition concentration at 50 % (IC50 value was in the range from 0.019 to 0.078 mg of mulberry extract per mL. Response surface methodology (RSM was used to determine the optimum extraction conditions and to investigate the effect of different variables on the observed properties of mulberry leaf extracts. The results show a good fit to the proposed model (R˄2>0.90. The optimal conditions for obtaining the highest extraction yield of phenolics and flavonoids were within the experimental range. The experimental values agreed with those predicted, thus indicating suitability of the used model and the success of RSM in optimizing the investigated extraction conditions.

  18. Application of response surface methodology for optimizing transesterification of Moringa oleifera oil: Biodiesel production

    International Nuclear Information System (INIS)

    Rashid, Umer; Anwar, Farooq; Ashraf, Muhammad; Saleem, Muhammad; Yusup, Suzana

    2011-01-01

    Highlights: → Biodiesel production from Moringa oil (MO) has been optimized for the first time using RSM. → RSM-optimized reaction conditions gave a high Moringa oil methyl esters (MOMEs) yield (94.3%). → Fuel properties of MOMEs yielded satisfied the ASTM D 6751 and EU 14214 specifications. → Present RSM-model can be useful for predicting optimum biodiesel yield from other oils. - Abstract: Response surface methodology (RSM), with central composite rotatable design (CCRD), was used to explore optimum conditions for the transesterification of Moringa oleifera oil. Effects of four variables, reaction temperature (25-65 deg. C), reaction time (20-90 min), methanol/oil molar ratio (3:1-12:1) and catalyst concentration (0.25-1.25 wt.% KOH) were appraised. The quadratic term of methanol/oil molar ratio, catalyst concentration and reaction time while the interaction terms of methanol/oil molar ratio with reaction temperature and catalyst concentration, reaction time with catalyst concentration exhibited significant effects on the yield of Moringa oil methyl esters (MOMEs)/biodiesel, p < 0.0001 and p < 0.05, respectively. Transesterification under the optimum conditions ascertained presently by RSM: 6.4:1 methanol/oil molar ratio, 0.80% catalyst concentration, 55 deg. C reaction temperature and 71.08 min reaction time offered 94.30% MOMEs yield. The observed and predicted values of MOMEs yield showed a linear relationship. GLC analysis of MOMEs revealed oleic acid methyl ester, with contribution of 73.22%, as the principal component. Other methyl esters detected were of palmitic, stearic, behenic and arachidic acids. Thermal stability of MOMEs produced was evaluated by thermogravimetric curve. The fuel properties such as density, kinematic viscosity, lubricity, oxidative stability, higher heating value, cetane number and cloud point etc., of MOMEs were found to be within the ASTM D6751 and EN 14214 biodiesel standards.

  19. Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology

    Science.gov (United States)

    Arachchi, Shanika Jeewantha Thewarapperuma; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Lee, Yang-Bong

    2017-01-01

    Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter’s L, a, and b values. ΔE was consequently set as the fifth response factor. In the statistical analyses, determination coefficients (R2) for their absorbance, Hunter’s L, a, b values, and ΔE were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter’s b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, 111°C reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter’s b value was 2.41 h reaction time, 114°C reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine. PMID:28401086

  20. Modelling of aflatoxin G1 reduction by kefir grain using response surface methodology.

    Science.gov (United States)

    Ansari, Farzaneh; Khodaiyan, Faramarz; Rezaei, Karamatollah; Rahmani, Anosheh

    2015-01-01

    Aflatoxin G1 (AFG1) is one of the main toxic contaminants in pistachio nuts and causes potential health hazards. Hence, AFG1 reduction is one of the main concerns in food safety. Kefir-grains contain symbiotic association of microorganisms well known for their aflatoxin decontamination effects. In this study, a central composite design (CCD) using response surface methodology (RSM) was applied to develop a model in order to predict AFG1 reduction in pistachio nuts by kefir-grain (already heated at 70 and 110°C). The independent variables were: toxin concentration (X1: 5, 10, 15, 20 and 25 ng/g), kefir-grain level (X2: 5, 10, 20, 10 and 25%), contact time (X3: 0, 2, 4, 6 and 8 h), and incubation temperature (X4: 20, 30, 40, 50 and 60°C). There was a significant reduction in AFG1 (p kefir-grain used. The variables including X1, X3 and the interactions between X2-X4 as well as X3-X4 have significant effects on AFG1 reduction. The model provided a good prediction of AFG1 reduction under the assay conditions. Optimization was used to enhance the efficiency of kefir-grain on AFG1 reduction. The optimum conditions for the highest AFG1 reduction (96.8%) were predicted by the model as follows: toxin concentration = 20 ng/g, kefir-grain level = 10%, contact time = 6 h, and incubation temperature = 30°C which validated practically in six replications.

  1. Application of response surface methodology for optimizing transesterification of Moringa oleifera oil: Biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Umer, E-mail: umer.rashid@yahoo.com [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 31750, Tronoh, Perak (Malaysia); Anwar, Farooq, E-mail: fqanwar@yahoo.com [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Ashraf, Muhammad, E-mail: ashrafbot@yahoo.com [Department of Botany, University of Agriculture, Faisalabad 38040 (Pakistan); Department of Botany and Microbiology, King Saud University, Riyadh (Saudi Arabia); Saleem, Muhammad [Department of Statistics, Government College University, Faisalabad 38000 (Pakistan); Yusup, Suzana, E-mail: drsuzana_yusuf@petronas.com.my [Chemical Engineering Department, Universiti Teknologi PETRONAS, Bandar Seri Iskandar 31750, Tronoh, Perak (Malaysia)

    2011-08-15

    Highlights: {yields} Biodiesel production from Moringa oil (MO) has been optimized for the first time using RSM. {yields} RSM-optimized reaction conditions gave a high Moringa oil methyl esters (MOMEs) yield (94.3%). {yields} Fuel properties of MOMEs yielded satisfied the ASTM D 6751 and EU 14214 specifications. {yields} Present RSM-model can be useful for predicting optimum biodiesel yield from other oils. - Abstract: Response surface methodology (RSM), with central composite rotatable design (CCRD), was used to explore optimum conditions for the transesterification of Moringa oleifera oil. Effects of four variables, reaction temperature (25-65 deg. C), reaction time (20-90 min), methanol/oil molar ratio (3:1-12:1) and catalyst concentration (0.25-1.25 wt.% KOH) were appraised. The quadratic term of methanol/oil molar ratio, catalyst concentration and reaction time while the interaction terms of methanol/oil molar ratio with reaction temperature and catalyst concentration, reaction time with catalyst concentration exhibited significant effects on the yield of Moringa oil methyl esters (MOMEs)/biodiesel, p < 0.0001 and p < 0.05, respectively. Transesterification under the optimum conditions ascertained presently by RSM: 6.4:1 methanol/oil molar ratio, 0.80% catalyst concentration, 55 deg. C reaction temperature and 71.08 min reaction time offered 94.30% MOMEs yield. The observed and predicted values of MOMEs yield showed a linear relationship. GLC analysis of MOMEs revealed oleic acid methyl ester, with contribution of 73.22%, as the principal component. Other methyl esters detected were of palmitic, stearic, behenic and arachidic acids. Thermal stability of MOMEs produced was evaluated by thermogravimetric curve. The fuel properties such as density, kinematic viscosity, lubricity, oxidative stability, higher heating value, cetane number and cloud point etc., of MOMEs were found to be within the ASTM D6751 and EN 14214 biodiesel standards.

  2. Optimization of a two stage process for biodiesel production from shea butter using response surface methodology

    Directory of Open Access Journals (Sweden)

    E.O. Ajala

    2017-12-01

    Full Text Available The challenges of biodiesel production from high free fatty acid (FFA shea butter (SB necessitated this study. The reduction of %FFA of SB by esterification and its subsequent utilization by transesterification for biodiesel production in a two stage process for optimization studies was investigated using response surface methodology based on a central composite design (CCD. Four operating conditions were investigated to reduce the %FFA of SB and increase the %yield of shea biodiesel (SBD. The operating conditions were temperature (40–60°C, agitation speed (200–1400 rpm, methanol (MeOH: oil mole ratio: 2:1–6:1 (w/w for esterification and 4:1–8:1 (w/w for transesterification and catalyst loading: 1–2% (H2SO4, (v/v for esterification and KOH, (w/w for transesterification. The significance of the parameters obtained in linear and non-linear form from the models were determined using analysis of variance (ANOVA. The optimal operating conditions that gave minimum FFA of 0.26% were 52.19°C, 200 rpm, 2:1 (w/w and 1.5% (v/v, while those that gave maximum yield of 92.16% SBD were 40°C, 800 rpm, 7:1 (w/w and 1% (w/w. The p-value of <0.0001 for each of the stages showed that the models were significant with R2 of 0.96 each. These results indicate the reproducibility of the models and showed that the RSM is suitable to optimize the esterification and transesterification of SB for SBD production. Therefore, RSM is a useful tool that can be employed in industrial scale production of SBD from high FFA SB.

  3. Optimization of Chlorination Process for Mature Leachate Disinfection Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Hamzeh Ali Jamali1

    2014-06-01

    Full Text Available Background: leachate from landfill contains high level of microbial pathogens which is considered as one of the most important threats for the environment. One of the common and simple methods for water and wastewater disinfection is chlorination, but it rarely has been used for leachate disinfection. The objective of this study was evaluating the efficiency of chlorine for leachate disinfection and optimization of the effect of concentration and contact time on the death of total and fecal coliforms, as a microbial contamination index. Methods: In this descriptive-analysis study, microbial indices monitoring in leachates initiated from landfill of Qazvin city were conducted for one year. After pre-tests, the range of chlorine concentration and contact time on the inactivation of microbial indices were determined. Central composite design (CCD and response surface methodology (RSM were applied to optimize chlorine concentration and contact time parameters effect on microbial inactivation. 13 runs of tests were performed on samples. Tests were included BOD, COD, total and fecal coliforms. All analytical experiments were according to the standard methods for the examination of water and wastewater. Results: Results of the study showed that microbial indices had relatively high sensitivity to inactivation by chlorination, which in the chlorine concentration of 2 mg/L and contact time of 9 min, and chlorine concentration of 0.5 mg/L and contact time of 12 min, 100% of total and fecal coliforms inactivated, respectively. The RSM method was used for analysis of bacterial inactivation. Analyses showed that in contact time of 9.4 min and chlorine concentration of 2.99 mg/L, the inactivation efficiency of total and fecal coliforms were 89.16% and 100%, respectively. Conclusions: Chlorine could be used for leachate disinfection. However, in high concentrations of organic matter in leachates, due to production potential of chlorination by-products, health

  4. Design and optimization of hydrogen production from hydrothermally pretreated sugarcane bagasse using response surface methodology.

    Science.gov (United States)

    Soares, Lais Américo; Braga, Juliana Kawanishi; Motteran, Fabrício; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2017-07-01

    Hydrogen production from hydrothermally pretreated (200 °C for 10 min at 16 bar) sugarcane bagasse was analyzed using response surface methodology. The yeast extract concentration and the temperature had a significant influence for hydrogen production (p-value 0.027 and 0.009, respectively). Maximum hydrogen production (17.7 mmol/L) was observed with 3 g/L yeast extract at 60 °C (C10). In this conditions were produced acetic acid (50.44 mg/L), butyric acid (209.71 mg/L), ethanol (38.4 mg/L), and methane (6.27 mmol/L). Lower hydrogen productions (3.5 mmol/L and 3.9 mmol/L) were observed under the conditions C7 (2 g/L of yeast extract, 35.8 °C) and C9 (1 g/L of yeast extract, 40 °C), respectively. The low yeast extract concentration and low temperature caused a negative effect on the hydrogen production. By means of denaturing gradient gel electrophoresis 20% of similarity was observed between the archaeal population of mesophilic (35 and 40 °C) and thermophilic (50, 60 and 64 °C) reactors. Likewise, similarity of 22% was noted between the bacterial population for the reactors with the lowest hydrogen production (3.5 mmol/L), at 35.8 °C and with the highest hydrogen production (17.7 mmol/L) at 60 °C demonstrating that microbial population modification was a function of incubation temperature variation.

  5. Enhancing the Bioconversion of Azelaic Acid to Its Derivatives by Response Surface Methodology.

    Science.gov (United States)

    Khairudin, Nurshafira; Basri, Mahiran; Fard Masoumi, Hamid Reza; Samson, Shazwani; Ashari, Siti Efliza

    2018-02-13

    Azelaic acid (AzA) and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA) to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435) is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R² of 0.9732).The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3) was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC 50 (50% inhibition of cell viability) value for AzA and AzA derivative was demonstrated. The IC 50 value for AzA was 85.28 μg/mL, whereas the IC 50 value for AzA derivative was more than 100 μg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.

  6. Adsorption of cellulase on cereal brans: a simple functional model from response surface methodology

    Directory of Open Access Journals (Sweden)

    Rui Sergio F. da Silva

    1980-11-01

    Full Text Available A functional model based on Langmuirian adsorption as a limiting mechanism was proposed to explain the effect of cellulase during the enzymatic pretreatment of bran, conducted prior to extraction of proteins, by wet alkaline process from wheat and buckwheat bran materials. The proposed model provides a good fit (r = 0.99 for the data generated thru predictive model taken from the response surface methodology, permitting calculation of a affinity constant (b and capacity constant (k, for wheat bran (b = 0.255 g/IU and k = 17.42% and buckwheat bran (b = 0.066g/IUand k = 78.74%.Modelo funcional baseado na adsorção de Langmuir como mecanismo limitante proposto para explicar o efeito da celulase durante o pré-tratamento enzimático de farelos, visando à extração de proteínas, através do método alcalino-úmido. O referido modelo ajusta se muito bem (r = 0,99 aos dados gerados com base em modelo preditivo obtido da metodologia da superfície de resposta. Pode-se calcular a constante de afinidade (b e a constante de capacidade (k para o farelo de trigo e farelo de trigo mourisco (sarraceno, usando uma equação análoga à isoterma de adsorção de Langmuir. Os resultados indicaram que o farelo de trigo mourisco apresenta uma capacidade mais alta para adsorver celulase e, conseqüentemente,'pode-se esperar uma resposta maior ao pré-tratamento com esta enzima.

  7. Optimization for the Production of Deoxynivalenoland Zearalenone by Fusarium graminearum UsingResponse Surface Methodology

    Directory of Open Access Journals (Sweden)

    Li Wu

    2017-02-01

    Full Text Available Fusarium mycotoxins deoxynivalenol (DON and zearalenone (ZEN are the most common contaminants in cereals worldwide, causing a wide range of adverse health effects on animals and humans. Many environmental factors can affect the production of these mycotoxins. Here, we have used response surface methodology (RSM to optimize the Fusarium graminearum strain 29 culture conditions for maximal toxin production. Three factors, medium pH, incubation temperature and time, were optimized using a Box-Behnken design (BBD. The optimized conditions for DON production were pH 4.91 and an incubation temperature of 23.75 °C for 28 days, while maximal ZEN production required pH 9.00 and an incubation temperature of 15.05 °C for 28 days. The maximum levels of DON and ZEN production were 2811.17 ng/mL and 23789.70 ng/mL, respectively. Considering the total level of DON and ZEN, desirable yields of the mycotoxins were still obtained with medium pH of 6.86, an incubation temperature of 17.76 °C and a time of 28 days. The corresponding experimental values, from the validation experiments, fitted well with these predictions. This suggests that RSM could be used to optimize Fusarium mycotoxin levels, which are further purified for use as potential mycotoxin standards. Furthermore, it shows that acidic pH is a determinant for DON production, while an alkaline environment and lower temperature (approximately 15 °C are favorable for ZEN accumulation. After extraction, separation and purification processes, the isolated mycotoxins were obtained through a simple purification process, with desirable yields, and acceptable purity. The mycotoxins could be used as potential analytical standards or chemical reagents for routine analysis.

  8. Antioxidant activity of polysaccharide extracted from Ganoderma lucidum using response surface methodology.

    Science.gov (United States)

    Kan, Yongjun; Chen, Tiqiang; Wu, Yanbin; Wu, Jianguo; Wu, Jinzhong

    2015-01-01

    Superfine grinding technology was applied for polysaccharide extraction from the fruiting bodies of Ganoderma lucidum, and response surface methodology (RSM) was used to optimize the effects of processing parameters on polysaccharide extraction yield. Results showed that the maximum yield of G. lucidum polysaccharides (GLP) was obtained at an optimum condition: extraction time 137 min, extraction temperature 66 ̊C, the ratio of water to material 35 mL/g, and the GLP extracting yield reached 2.44% under this condition. GLP were precipitated into three crude polysaccharides, viz. GLP40, GLP60 and GLP80. The basic characterization of polysaccharides was determined by using HPLC and FT-IR methods. GLP, GLP80, GLP60, and GLP40 were composed of Man, Rib, Glc, Gal and Fuc with the molar ratios of 1.27:0.36:22.89:1.61:0.33, 1.40:0.31:23.02:3.46:0.91, 0.96:0.34:25.76:2.47:0.46, and 2.81:1.42:23.83:1.61:0.33, respectively. The result of FT-IR suggested that the monosaccharide residue of the four polysaccharides was β-pyranoid ring. Moreover, the antioxidant activities of these four polysaccharides were evaluated. The results showed that GLP80 had the best reducing power, DPPH radical scavenging ability and oxygen radical scavenging ability followed by GLP, GLP60 and GLP40. Our results demonstrated that RSM might be a valuable technique for optimizing the efficient extraction of GLP, and G. lucidum could be considered as sources of natural antioxidants and preservatives of food industry. Moreover, polysaccharides, especially GLP80, extracted from the fruiting bodies of G. lucidum, exhibited promising antioxidant activities. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Enhanced methane production of vinegar residue by response surface methodology (RSM).

    Science.gov (United States)

    Feng, Jiayu; Zhang, Jiyu; Zhang, Jiafu; He, Yanfeng; Zhang, Ruihong; Chen, Chang; Liu, Guangqing

    2017-12-01

    As the by-product of the vinegar production process, a large number of vinegar residue has been abandoned and caused a serious environmental pollution. Anaerobic digestion has been proved to be able to dispose and convert vinegar residue into bioenergy but still need to improve the efficiency. This study applied central composite design of response surface methodology to investigate the influences of feed to inoculum ratio, organic loading, and initial pH on methane production and optimize anaerobic digestion condition. The maximum methane yield of 203.91 mL gVS -1 and biodegradability of 46.99% were obtained at feed to inoculum ratio of 0.5, organic loading of 31.49 gVS L -1 , and initial pH of 7.29, which was considered as the best condition. It has a very significant improvement of 69.48% for methane production and 52.02% for biodegradability compared with our previous study. Additionally, a high methane yield of 182.09 mL gVS -1 was obtained at feed to inoculum ratio of 1.5, organic loading of 46.22 gVS L -1 , and initial pH of 7.32. And it is more appropriate to apply this condition in industrial application owing to the high feed to inoculum ratio and organic loading. Besides, a significant interaction was found between feed to inoculum ratio and organic loading. This study maximized the methane production of vinegar residue and made a good foundation for further study and future industrial application.

  10. 1-Hexene Polymerization Using Ziegler-Natta Catalytic System with Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Maliheh Mazaheriyan

    2017-07-01

    Full Text Available The effects of process conditions and their interactions on the catalyst activity in 1-hexene polymerization were studied with design of experiments by response surface methodology (RSM using a commercial Ziegler-Natta (ZN catalyst in the form of TiCl4/MgCl2/Di-n-butyl phthalate. The effect of different operational variables on the catalyst activity was examined by performing the primary experiments of 1-hexene polymerization.  Among different operational variables, three variables including monomer concentration, polymerization temperature and cocatalyst/catalyst molar ratio (Al/Ti were considered as the main parameters which affected the catalyst activity in the 1-hexene polymerization. The Box-Behnken model with three main parameters in three level responses for each factor was applied to analyze the parameter relationships. After demonstrating the reproducibility of the experimental results, the statistical analysis of experimental data showed that the monomer concentration and Al/Ti molar ratio affected the catalyst activity significantly. It was found that, at room temperature, by increasing the monomer concentration from 80.0 mmol to 239.9 mmol, the activity of the studied ZN catalyst increased from 75.2 to 265.1 gpoly(1-hexene/gcat. In addition, by changing the Al/Ti ratio from 45.9 to 136.8, the catalyst activity increased from 145.2 to 265.1 gpoly(1-hexene/gcat. The maximum activity of catalyst was obtained at the polymerization temperature around 25°C, and by increasing the temperature the activity of studied catalyst decreased. Based on the RSM, the best polymerization condition was obtained at a polymerization temperature of about 35°C, Al/Ti ratio of 136.8, and monomer concentration of 239.9 mmol, which resulted in maximum productivity of the catalyst.

  11. Use of response surface methodology for optimization of fluoride adsorption in an aqueous solution by Brushite

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    M. Mourabet

    2017-05-01

    Full Text Available In the present study, Response surface methodology (RSM was employed for the removal of fluoride on Brushite and the process parameters were optimized. Four important process parameters including initial fluoride concentration (40–50 mg/L, pH (4–11, temperature (10–40 °C and B dose (0.05–0.15 g were optimized to obtain the best response of fluoride removal using the statistical Box–Behnken design. The experimental data obtained were analyzed by analysis of variance (ANOVA and fitted to a second-order polynomial equation using multiple regression analysis. Numerical optimization applying desirability function was used to identify the optimum conditions for maximum removal of fluoride. The optimum conditions were found to be initial concentration = 49.06 mg/L, initial solution pH = 5.36, adsorbent dose = 0.15 g and temperature = 31.96 °C. A confirmatory experiment was performed to evaluate the accuracy of the optimization procedure and maximum fluoride removal of 88.78% was achieved under the optimized conditions. Several error analysis equations were used to measure the goodness-of-fit. Kinetic studies showed that the adsorption followed a pseudo-second order reaction. The equilibrium data were analyzed using Langmuir, Freundlich, and Sips isotherm models at different temperatures. The Langmuir model was found to be describing the data. The adsorption capacity from the Langmuir isotherm (QL was found to be 29.212, 35.952 and 36.260 mg/g at 298, 303, and 313 K respectively.

  12. Modeling and process optimization of electrospinning of chitosan-collagen nanofiber by response surface methodology

    Science.gov (United States)

    Amiri, Nafise; Moradi, Ali; Abolghasem Sajjadi Tabasi, Sayyed; Movaffagh, Jebrail

    2018-04-01

    Chitosan-collagen composite nanofiber is of a great interest to researchers in biomedical fields. Since the electrospinning is the most popular method for nanofiber production, having a comprehensive knowledge of the electrospinning process is beneficial. Modeling techniques are precious tools for managing variables in the electrospinning process, prior to the more time- consuming and expensive experimental techniques. In this study, a central composite design of response surface methodology (RSM) was employed to develop a statistical model as well as to define the optimum condition for fabrication of chitosan-collagen nanofiber with minimum diameter. The individual and the interaction effects of applied voltage (10–25 kV), flow rate (0.5–1.5 mL h‑1), and needle to collector distance (15–25 cm) on the fiber diameter were investigated. ATR- FTIR and cell study were done to evaluate the optimized nanofibers. According to the RSM, a two-factor interaction (2FI) model was the most suitable model. The high regression coefficient value (R 2 ≥ 0.9666) of the fitted regression model and insignificant lack of fit (P = 0.0715) indicated that the model was highly adequate in predicting chitosan-collagen nanofiber diameter. The optimization process showed that the chitosan-collagen nanofiber diameter of 156.05 nm could be obtained in 9 kV, 0.2 ml h‑1, and 25 cm which was confirmed by experiment (155.92 ± 18.95 nm). The ATR-FTIR and cell study confirmed the structure and biocompatibility of the optimized membrane. The represented model could assist researchers in fabricating chitosan-collagen electrospun scaffolds with a predictable fiber diameter, and optimized chitosan-collagen nanofibrous mat could be a potential candidate for wound healing and tissue engineering.

  13. Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology.

    Science.gov (United States)

    Arachchi, Shanika Jeewantha Thewarapperuma; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Lee, Yang-Bong

    2017-03-01

    Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ΔE was consequently set as the fifth response factor. In the statistical analyses, determination coefficients (R 2 ) for their absorbance, Hunter's L, a, b values, and ΔE were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, 111°C reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, 114°C reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

  14. Optimization of lead adsorption of mordenite by response surface methodology: characterization and modification.

    Science.gov (United States)

    Turkyilmaz, Havva; Kartal, Tolga; Yigitarslan Yildiz, Sibel

    2014-01-06

    In order to remove heavy metals, water treatment by adsorption of zeolite is gaining momentum due to low cost and good performance. In this research, the natural mordenite was used as an adsorbent to remove lead ions in an aqueous solution. The effects of adsorption temperature, time and initial concentration of lead on the adsorption yield were investigated. Response surface methodology based on Box-Behnken design was applied for optimization. Adsorption data were analyzed by isotherm models. The process was investigated by batch experiments; kinetic and thermodynamic studies were carried out. Adsorption yields of natural and hexadecyltrimethylammonium-bromide-modified mordenite were compared. The optimum conditions of maximum adsorption (nearly 84 percent) were found as follows: adsorption time of 85-90 min, adsorption temperature of 50°C, and initial lead concentration of 10 mg/L. At the same optimum conditions, modification of mordenite produced 97 percent adsorption yield. The most appropriate isotherm for the process was the Freundlich. Adsorption rate was found as 4.4. Thermodynamic calculations showed that the adsorption was a spontaneous and an exothermic process. Quadratic model and reduced cubic model were developed to correlate the variables with the adsorption yield of mordenite. From the analysis of variance, the most influential factor was identified as initial lead concentration. At the optimum conditions modification increased the adsorption yield up to nearly 100 percent. Mordenite was found an applicable adsorbent for lead ions especially in dilute solutions and may also be applicable in more concentrated ones with lower yields.

  15. Enhancing the Bioconversion of Azelaic Acid to Its Derivatives by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Nurshafira Khairudin

    2018-02-01

    Full Text Available Azelaic acid (AzA and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435 is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R2 of 0.9732.The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3 was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC50 (50% inhibition of cell viability value for AzA and AzA derivative was demonstrated. The IC50 value for AzA was 85.28 μg/mL, whereas the IC50 value for AzA derivative was more than 100 μg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.

  16. Optimization of the ethanolysis of Raphanus sativus (L. Var.) crude oil applying the response surface methodology.

    Science.gov (United States)

    Domingos, Anderson Kurunczi; Saad, Emir Bolzani; Wilhelm, Helena Maria; Ramos, Luiz Pereira

    2008-04-01

    Raphanus sativus (L. Var) is a perennial plant of the Brassicaceae (or Cruciferae) family whose oil has not been investigated in detail for biodiesel production, particularly when ethanol is used as the alcoholysis agent. In this work, response surface methodology (RSM) was used to determine the optimum condition for the ethanolysis of R. sativus crude oil. Three process variables were evaluated at two levels (2(3) experimental design): the ethanol:oil molar ratio (6:1 and 12:1), the catalyst concentration in relation to oil mass (0.4 and 0.8 wt% NaOH) and the alcoholysis temperature (45 and 65 degrees C). When the experimental results were tentatively adjusted by linear regression, only 58.15% of its total variance was explained. Therefore, a quadratic model was investigated to improve the poor predictability of the linear model. To apply the quadratic model, the 2(3) experimental design had to be expanded to a circumscribed central composite design. This allowed the development of a response surface that was able to predict 97.75% of the total variance of the system. Validation was obtained by performing one ethanolysis experiment at the conditions predicted by the model (38 degrees C, ethanol:oil molar ratio of 11.7:1 and 0.6 wt% NaOH). The resulting ester yield (104.10 wt% or 99.10% of the theoretical yield of 105.04 wt%) was shown to be the highest among all conditions tested in this study. The second ethanolysis stage of the best RSM product required 50% less ethanol and 90% less catalyst consumption. The amount of ethyl esters obtained after this procedure reached 94.5% of the theoretical yield. The resulting ethyl esters were shown to comply with most of the Brazilian biodiesel specification parameters except for oxidation stability. Addition of 500 ppm of BHT to the esters, however, complied with the specification target of 6h. The application of 2 wt% Magnesol after the second ethanolysis stage eliminated the need for water washing and helped generate a

  17. Clearance of surface-contaminated objects from the controlled area of a nuclear facility. Application of the SUDOQU methodology

    Energy Technology Data Exchange (ETDEWEB)

    Russo, F.; Mommaert, C. [Bel V, Brussels (Belgium); Dillen, T. van [National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands)

    2018-01-15

    The lack of clearly defined surface-clearance levels in the Belgian regulation led Bel V to start a collaboration with the Dutch National Institute for Public Health and the Environment (RIVM) to evaluate the applicability of the SUDOQU methodology for the derivation of nuclide-specific surface-clearance criteria for objects released from nuclear facilities. SUDOQU is a methodology for the dose assessment of exposure to a surface-contaminated object, with the innovative assumption of a time-dependent surface activity whose evolution is influenced by removal and deposition mechanisms. In this work, calculations were performed to evaluate the annual effective dose resulting from the use of a typical office item, e.g. a bookcase. Preliminary results allow understanding the interdependencies between the model's underlying mechanisms, and show a strong sensitivity to the main input parameters. The results were benchmarked against those from a model described in Radiation Protection 101, to investigate the impact of the model's main assumptions. Results of the two models were in good agreement. The SUDOQU methodology appears to be a flexible and powerful tool, suitable for the proposed application. Therefore, the project will be extended to more generic study cases, to eventually develop surface-clearance levels applicable to objects leaving nuclear facilities.

  18. Classification of reflected signals from cavitated tooth surfaces using an artificial intelligence technique incorporating a fiber optic displacement sensor

    Science.gov (United States)

    Rahman, Husna Abdul; Harun, Sulaiman Wadi; Arof, Hamzah; Irawati, Ninik; Musirin, Ismail; Ibrahim, Fatimah; Ahmad, Harith

    2014-05-01

    An enhanced dental cavity diameter measurement mechanism using an intensity-modulated fiber optic displacement sensor (FODS) scanning and imaging system, fuzzy logic as well as a single-layer perceptron (SLP) neural network, is presented. The SLP network was employed for the classification of the reflected signals, which were obtained from the surfaces of teeth samples and captured using FODS. Two features were used for the classification of the reflected signals with one of them being the output of a fuzzy logic. The test results showed that the combined fuzzy logic and SLP network methodology contributed to a 100% classification accuracy of the network. The high-classification accuracy significantly demonstrates the suitability of the proposed features and classification using SLP networks for classifying the reflected signals from teeth surfaces, enabling the sensor to accurately measure small diameters of tooth cavity of up to 0.6 mm. The method remains simple enough to allow its easy integration in existing dental restoration support systems.

  19. Scanning Electron Microscope (SEM) Evaluation of the Interface between a Nanostructured Calcium-Incorporated Dental Implant Surface and the Human Bone.

    Science.gov (United States)

    Mangano, Francesco; Raspanti, Mario; Maghaireh, Hassan; Mangano, Carlo

    2017-12-17

    Purpose . The aim of this scanning electron microscope (SEM) study was to investigate the interface between the bone and a novel nanostructured calcium-incorporated dental implant surface in humans. Methods . A dental implant (Anyridge ® , Megagen Implant Co., Gyeongbuk, South Korea) with a nanostructured calcium-incorporated surface (Xpeed ® , Megagen Implant Co., Gyeongbuk, South Korea), which had been placed a month earlier in a fully healed site of the posterior maxilla (#14) of a 48-year-old female patient, and which had been subjected to immediate functional loading, was removed after a traumatic injury. Despite the violent trauma that caused mobilization of the fixture, its surface appeared to be covered by a firmly attached, intact tissue; therefore, it was subjected to SEM examination. The implant surface of an unused nanostructured calcium-incorporated implant was also observed under SEM, as control. Results . The surface of the unused implant showed a highly-structured texture, carved by irregular, multi-scale hollows reminiscent of a fractal structure. It appeared perfectly clean and devoid of any contamination. The human specimen showed trabecular bone firmly anchored to the implant surface, bridging the screw threads and filling the spaces among them. Conclusions . Within the limits of this human histological report, the sample analyzed showed that the nanostructured calcium-incorporated surface was covered by new bone, one month after placement in the posterior maxilla, under an immediate functional loading protocol.

  20. Updating Optimal Decisions Using Game Theory and Exploring Risk Behavior Through Response Surface Methodology

    National Research Council Canada - National Science Library

    Jordan, Jeremy D

    2007-01-01

    .... Methodology is developed that allows a decision maker to change his perceived optimal policy based on available knowledge of the opponents strategy, where the opponent is a rational decision maker...

  1. Safety Assessment Methodologies and Their Application in Development of Near Surface Waste Disposal Facilities--ASAM Project

    International Nuclear Information System (INIS)

    Batandjieva, B.; Metcalf, P.

    2003-01-01

    Safety of near surface disposal facilities is a primary focus and objective of stakeholders involved in radioactive waste management of low and intermediate level waste and safety assessment is an important tool contributing to the evaluation and demonstration of the overall safety of these facilities. It plays significant role in different stages of development of these facilities (site characterization, design, operation, closure) and especially for those facilities for which safety assessment has not been performed or safety has not been demonstrated yet and the future has not been decided. Safety assessments also create the basis for the safety arguments presented to nuclear regulators, public and other interested parties in respect of the safety of existing facilities, the measures to upgrade existing facilities and development of new facilities. The International Atomic Energy Agency (IAEA) has initiated a number of research coordinated projects in the field of development and improvement of approaches to safety assessment and methodologies for safety assessment of near surface disposal facilities, such as NSARS (Near Surface Radioactive Waste Disposal Safety Assessment Reliability Study) and ISAM (Improvement of Safety Assessment Methodologies for Near Surface Disposal Facilities) projects. These projects were very successful and showed that there is a need to promote the consistent application of the safety assessment methodologies and to explore approaches to regulatory review of safety assessments and safety cases in order to make safety related decisions. These objectives have been the basis of the IAEA follow up coordinated research project--ASAM (Application of Safety Assessment Methodologies for Near Surface Disposal Facilities), which will commence in November 2002 and continue for a period of three years

  2. Understanding the stability of Fe incorporation within Mn3N2(0 0 1) surfaces: An ab-initio study

    International Nuclear Information System (INIS)

    Guerrero-Sánchez, J.; Mandru, Andrada-Oana; Takeuchi, Noboru; Cocoletzi, Gregorio H.; Smith, Arthur R.

    2016-01-01

    Graphical abstract: - Highlights: • The Fe incorporation into inner layers of the Mn 3 N 2 surfaces is stable in all range of chemical potential. • Displaced Mn atoms forming cluster-like structures induce the stability of incorporated Fe atoms. • Antiferromagnetic alignment in the [0 0 1] direction and in-plane Ferromagnetic Fe–Fe and Fe–Mn alignments are the same as in Mn 3 N 2 bulk structure. • Incorporated Fe layers contribute to the metallic character of these surfaces. - Abstract: We present first principles spin-polarized calculations of the adsorption and incorporation of iron in the Mn 3 N 2 (0 0 1) surfaces. By means of a surface formation energy criterion, it is demonstrated that Fe incorporation is energetically stable for all studied surfaces. An Fe bilayer formation is achieved after Fe atoms displace Mn atoms in the sub-surface N-vacancy layers. An analysis of the magnetic coupling shows an antiferromagnetic alignment along the [0 0 1] direction as in the clean, ideal surfaces. Also, the in-plane magnetic coupling between Fe–Fe and Fe–Mn shows a ferromagnetic tendency, similar to the clean, ideally terminated surfaces. These results clearly indicate that Fe behaves like Mn when adsorbed into the Mn 3 N 2 surface. Density of states calculations of the stable structures show a slight deviation from the antiferromagnetic-like behavior, with the most important contribution around the Fermi level coming from the Fe-d and Mn-d orbitals.

  3. Understanding the stability of Fe incorporation within Mn{sub 3}N{sub 2}(0 0 1) surfaces: An ab-initio study

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Sánchez, J., E-mail: guerrero@ifuap.buap.mx [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Benemérita Universidad Autónoma de Puebla, Instituto de Física “Ing Luis Rivera Terrazas”, Apartado Postal J-48, Puebla 72570, México (Mexico); Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada, Baja California Codigo Postal 22800, México (Mexico); Mandru, Andrada-Oana [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Takeuchi, Noboru [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States); Centro de Nanociencias y Nanotecnologia, Universidad Nacional Autónoma de México, Apartado Postal 14, Ensenada, Baja California Codigo Postal 22800, México (Mexico); Cocoletzi, Gregorio H. [Benemérita Universidad Autónoma de Puebla, Instituto de Física “Ing Luis Rivera Terrazas”, Apartado Postal J-48, Puebla 72570, México (Mexico); Smith, Arthur R. [Department of Physics and Astronomy, Nanoscale and Quantum Phenomena Institute, Ohio University, Athens, OH 45701 (United States)

    2016-02-15

    Graphical abstract: - Highlights: • The Fe incorporation into inner layers of the Mn{sub 3}N{sub 2} surfaces is stable in all range of chemical potential. • Displaced Mn atoms forming cluster-like structures induce the stability of incorporated Fe atoms. • Antiferromagnetic alignment in the [0 0 1] direction and in-plane Ferromagnetic Fe–Fe and Fe–Mn alignments are the same as in Mn{sub 3}N{sub 2} bulk structure. • Incorporated Fe layers contribute to the metallic character of these surfaces. - Abstract: We present first principles spin-polarized calculations of the adsorption and incorporation of iron in the Mn{sub 3}N{sub 2}(0 0 1) surfaces. By means of a surface formation energy criterion, it is demonstrated that Fe incorporation is energetically stable for all studied surfaces. An Fe bilayer formation is achieved after Fe atoms displace Mn atoms in the sub-surface N-vacancy layers. An analysis of the magnetic coupling shows an antiferromagnetic alignment along the [0 0 1] direction as in the clean, ideal surfaces. Also, the in-plane magnetic coupling between Fe–Fe and Fe–Mn shows a ferromagnetic tendency, similar to the clean, ideally terminated surfaces. These results clearly indicate that Fe behaves like Mn when adsorbed into the Mn{sub 3}N{sub 2} surface. Density of states calculations of the stable structures show a slight deviation from the antiferromagnetic-like behavior, with the most important contribution around the Fermi level coming from the Fe-d and Mn-d orbitals.

  4. Design methodology for nano-engineered surfaces to control adhesion: Application to the anti-adhesion of particles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taekyung [National Center for Optically-Assisted Ultra-High Precision Mechanical Systems, Yonsei University, Seoul 03722 (Korea, Republic of); School of Mechanical Engineering, Yonsei University, Seoul 03722 (Korea, Republic of); Min, Cheongwan [National Center for Optically-Assisted Ultra-High Precision Mechanical Systems, Yonsei University, Seoul 03722 (Korea, Republic of); Jung, Myungki; Lee, Jinhyung; Park, Changsu [National Center for Optically-Assisted Ultra-High Precision Mechanical Systems, Yonsei University, Seoul 03722 (Korea, Republic of); School of Mechanical Engineering, Yonsei University, Seoul 03722 (Korea, Republic of); Kang, Shinill, E-mail: snlkang@yonsei.ac.kr [National Center for Optically-Assisted Ultra-High Precision Mechanical Systems, Yonsei University, Seoul 03722 (Korea, Republic of); School of Mechanical Engineering, Yonsei University, Seoul 03722 (Korea, Republic of)

    2016-12-15

    Highlights: • A design method using the Derjaguin approximation with FEA for low-adhesion surface. • Fabrication of nanostructures with small adhesion forces by presented design method. • Characterization of adhesion force via AFM FD-curve with modified atypical tips. • Verification of low-adhesion of designed surfaces using centrifugal detachment tests. • Investigation of interdependence of hydrophobicity and anti-adhesion force. - Abstract: With increasing demand for means of controlling surface adhesion in various applications, including the semiconductor industry, optics, micro/nanoelectromechanical systems, and the medical industry, nano-engineered surfaces have attracted much attention. This study suggests a design methodology for nanostructures using the Derjaguin approximation in conjunction with finite element analysis for the control of adhesion forces. The suggested design methodology was applied for designing a nano-engineered surface with low-adhesion properties. To verify this, rectangular and sinusoidal nanostructures were fabricated and analyzed using force-distance curve measurements using atomic force microscopy and centrifugal detachment testing. For force-distance curve measurements, modified cantilevers with tips formed with atypical particles were used. Subsequently, centrifugal detachment tests were also conducted. The surface wettability of rectangular and sinusoidal nanostructures was measured and compared with the measured adhesion force and the number of particles remaining after centrifugal detachment tests.

  5. Incorporation of velocity-dependent restitution coefficient and particle surface friction into kinetic theory for modeling granular flow cooling.

    Science.gov (United States)

    Duan, Yifei; Feng, Zhi-Gang

    2017-12-01

    Kinetic theory (KT) has been successfully used to model rapid granular flows in which particle interactions are frictionless and near elastic. However, it fails when particle interactions become frictional and inelastic. For example, the KT is not able to accurately predict the free cooling process of a vibrated granular medium that consists of inelastic frictional particles under microgravity. The main reason that the classical KT fails to model these flows is due to its inability to account for the particle surface friction and its inelastic behavior, which are the two most important factors that need be considered in modeling collisional granular flows. In this study, we have modified the KT model that is able to incorporate these two factors. The inelasticity of a particle is considered by establishing a velocity-dependent expression for the restitution coefficient based on many experimental studies found in the literature, and the particle friction effect is included by using a tangential restitution coefficient that is related to the particle friction coefficient. Theoretical predictions of the free cooling process by the classical KT and the improved KT are compared with the experimental results from a study conducted on an airplane undergoing parabolic flights without the influence of gravity [Y. Grasselli, G. Bossis, and G. Goutallier, Europhys. Lett. 86, 60007 (2009)10.1209/0295-5075/86/60007]. Our results show that both the velocity-dependent restitution coefficient and the particle surface friction are important in predicting the free cooling process of granular flows; the modified KT model that integrates these two factors is able to improve the simulation results and leads to better agreement with the experimental results.

  6. Incorporation of velocity-dependent restitution coefficient and particle surface friction into kinetic theory for modeling granular flow cooling

    Science.gov (United States)

    Duan, Yifei; Feng, Zhi-Gang

    2017-12-01

    Kinetic theory (KT) has been successfully used to model rapid granular flows in which particle interactions are frictionless and near elastic. However, it fails when particle interactions become frictional and inelastic. For example, the KT is not able to accurately predict the free cooling process of a vibrated granular medium that consists of inelastic frictional particles under microgravity. The main reason that the classical KT fails to model these flows is due to its inability to account for the particle surface friction and its inelastic behavior, which are the two most important factors that need be considered in modeling collisional granular flows. In this study, we have modified the KT model that is able to incorporate these two factors. The inelasticity of a particle is considered by establishing a velocity-dependent expression for the restitution coefficient based on many experimental studies found in the literature, and the particle friction effect is included by using a tangential restitution coefficient that is related to the particle friction coefficient. Theoretical predictions of the free cooling process by the classical KT and the improved KT are compared with the experimental results from a study conducted on an airplane undergoing parabolic flights without the influence of gravity [Y. Grasselli, G. Bossis, and G. Goutallier, Europhys. Lett. 86, 60007 (2009), 10.1209/0295-5075/86/60007]. Our results show that both the velocity-dependent restitution coefficient and the particle surface friction are important in predicting the free cooling process of granular flows; the modified KT model that integrates these two factors is able to improve the simulation results and leads to better agreement with the experimental results.

  7. Optimization of ultrasonic assisted extraction of antioxidants from black soybean (Glycine max var) sprouts using response surface methodology.

    Science.gov (United States)

    Lai, Jixiang; Xin, Can; Zhao, Ya; Feng, Bing; He, Congfen; Dong, Yinmao; Fang, Yun; Wei, Shaomin

    2013-01-16

    Response surface methodology (RSM) using a central composite design (CCD) was employed to optimize the conditions for extraction of antioxidants from black soybean (Glycine max var) sprouts. Three influencing factors: liquid-solid ratio, period of ultrasonic assisted extraction and extraction temperature were investigated in the ultrasonic aqueous extraction. Then Response Surface Methodology (RSM) was applied to optimize the extraction process focused on DPPH radical-scavenging capacity of the antioxidants with respect to the above influencing factors. The best combination of each significant factor was determined by RSM design and optimum pretreatment conditions for maximum radical-scavenging capacity were established to be liquid-solid ratio of 29.19:1, extraction time of 32.13 min, and extraction temperature of 30 °C. Under these conditions, 67.60% of DPPH radical-scavenging capacity was observed experimentally, similar to the theoretical prediction of 66.36%.

  8. [Optimization of enzymatic extraction of polysaccharide from Dendrobium officinale by box-Behnken design and response surface methodology].

    Science.gov (United States)

    Hu, Jian-mei; Li, Jing-ling; Feng, Peng; Zhang, Xiang-dong; Zhong, Ming

    2014-01-01

    To optimize the processing of enzymatic extraction of polysaccharide from Dendrobium officinale. With phenol-sulfuric acid method and the DNS determination polysaccharide, Box-Behnken response surface methodology was used to optimize different enzyme dosage, reaction temperature and reaction time by using Design-Expert 8.05 software for data analysis and processing. According to Box-Behnken response, the best extraction conditions for the polysaccharide from Dendrobium officinale were as follows: the amount of enzyme complex was 3.5 mg/mL, hydrolysis temperature was 53 degrees C, and reaction time was 70 min. In accordance with the above process, the polysaccharide yield was 16.11%. Box-Behnken response surface methodology is used to optimize the enzymatic extraction process for the polysaccharide in this study, which is effective, stable and feasible.

  9. [Optimization of Polysaccharide Extraction from Spirodela polyrrhiza by Plackett-Burman Design Combined with Box-Behnken Response Surface Methodology].

    Science.gov (United States)

    Jiang, Zheng; Wang, Hong; Wu, Qi-nan

    2015-06-01

    To optimize the processing of polysaccharide extraction from Spirodela polyrrhiza. Five factors related to extraction rate of polysaccharide were optimized by the Plackett-Burman design. Based on this study, three factors, including alcohol volume fraction, extraction temperature and ratio of material to liquid, were regarded as investigation factors by Box-Behnken response surface methodology. The effect order of three factors on the extraction rate of polysaccharide from Spirodela polyrrhiza were as follows: extraction temperature, alcohol volume fraction,ratio of material to liquid. According to Box-Behnken response, the best extraction conditions were: alcohol volume fraction of 81%, ratio of material to liquid of 1:42, extraction temperature of 100 degrees C, extraction time of 60 min for four times. Plackett-Burman design and Box-Behnken response surface methodology used to optimize the extraction process for the polysaccharide in this study is effective and stable.

  10. Ultrasonic Extraction of Antioxidants from Chinese Sumac (Rhus typhina L.) Fruit Using Response Surface Methodology and Their Characterization

    OpenAIRE

    Lai, Jixiang; Wang, Huifang; Wang, Donghui; Fang, Fang; Wang, Fengzhong; Wu, Tao

    2014-01-01

    For the first time, response surface methodology (RSM) using a Box-Behnken Design (BBD) was employed to optimize the conditions for ultrasonic assisted extraction (UAE) of antioxidants from Chinese sumac (Rhus typhina L.) fruits. Initially, influencing factors such as liquid-solid ratio, duration of ultrasonic assisted extraction, pH range, extraction temperature and ethanol concentration were identified using single-factor experiments. Then, with respect to the three most significant influen...

  11. The antagonic effect of iron and zinc in formulations of feeding diets studied by response surface methodology for mixtures

    OpenAIRE

    BUENO, Luciana

    2008-01-01

    Nutritional therapy with enteral diets became substantially specialized over the last years. This work's aim was to study the effect of the components of a formulation: fiber, calcium and medium-chain triglycerides for dialysability of minerals. Analysis of multiple variables was carried out using response surface methodology. The level curve showed an antagonic effect of interaction between iron and zinc. TCM was the variable responsible for characterizing competition between the two mineral...

  12. Formulation and Evaluation of Cookies Containing Germinated Pigeon Pea, Fermented Sorghum and Cocoyam Flour Blends using Mixture Response Surface Methodology

    OpenAIRE

    Laura C. Okpala; Eric C. Okoli

    2011-01-01

    Cookies were produced from blends of germinated pigeon pea, fermented sorghum and cocoyam flours. The study was carried out to evaluate the effects of varying the proportions of these components on the sensory and protein quality of the cookies. The sensory attributes studied were colour, taste, texture, crispiness and general acceptability while the protein quality indices were Biological Value (BV) and Net Protein Utilization (NPU). Mixture response surface methodology was used to model the...

  13. Hybrid response surface methodology-artificial neural network optimization of drying process of banana slices in a forced convective dryer.

    Science.gov (United States)

    Taheri-Garavand, Amin; Karimi, Fatemeh; Karimi, Mahmoud; Lotfi, Valiullah; Khoobbakht, Golmohammad

    2017-01-01

    The aim of the study is to fit models for predicting surfaces using the response surface methodology and the artificial neural network to optimize for obtaining the maximum acceptability using desirability functions methodology in a hot air drying process of banana slices. The drying air temperature, air velocity, and drying time were chosen as independent factors and moisture content, drying rate, energy efficiency, and exergy efficiency were dependent variables or responses in the mentioned drying process. A rotatable central composite design as an adequate method was used to develop models for the responses in the response surface methodology. Moreover, isoresponse contour plots were useful to predict the results by performing only a limited set of experiments. The optimum operating conditions obtained from the artificial neural network models were moisture content 0.14 g/g, drying rate 1.03 g water/g h, energy efficiency 0.61, and exergy efficiency 0.91, when the air temperature, air velocity, and drying time values were equal to -0.42 (74.2 ℃), 1.00 (1.50 m/s), and -0.17 (2.50 h) in the coded units, respectively.

  14. Optimization of the ultrasound-assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology.

    Science.gov (United States)

    Chen, Yang; Yin, Li-Zi; Zhao, Ling; Shu, Gang; Yuan, Zhi-Xiang; Fu, Hua-Lin; Lv, Cheng; Lin, Ju-Chun

    2017-11-01

    The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid-solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus. Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Safety and effectiveness of early loaded maxillary titanium implants with a novel nanostructured calcium-incorporated surface (Xpeed): 3-year results from a pilot multicenter randomised controlled trial.

    Science.gov (United States)

    Felice, Pietro; Grusovin, Maria Gabriella; Barausse, Carlo; Grandi, Giovanni; Esposito, Marco

    2015-01-01

    To evaluate clinical safety and effectiveness of a novel calcium-incorporated titanium implant surface (Xpeed, MegaGen Implant Co., Gyeongbuk, South Korea). Sixty patients were randomised to receive one to six implants in the maxilla with either calcium-incorporated (Xpeed) or control resorbable blasted media (RBM) surfaces, according to a parallel group design at two centres. Implants were submerged and exposed at three different endpoints in equal groups of 20 patients, each at 12, 10 and 8 weeks, respectively. Within 2 weeks, implants were functionally loaded with provisional or definitive prostheses. Outcome measures were prosthesis failures, implant failures, any complications and peri-implant marginal bone level changes. Thirty patients received 45 calcium-incorporated implants and 30 patients received 42 control titanium implants. Three years after loading four patients dropped-out from the Xpeed group and one from the RBM group. No prosthesis or implant failures occurred. There were no statistically significant differences between the groups for complications (P = 0.91; difference in proportions = 0.79 %; 95% CI -0.71 to 2.29) and mean marginal bone level changes (P = 0.88; mean difference = -0.02 mm; 95% CI -0.26 to 0.22). Both implant surfaces provided good clinical results and no significant difference was found when comparing titanium implants with a nanostructured calcium-incorporated surface versus implants with RBM surfaces.

  16. Spatio-temporal image-based parametric water surface reconstruction: a novel methodology based on refraction

    Science.gov (United States)

    Engelen, L.; Creëlle, S.; Schindfessel, L.; De Mulder, T.

    2018-03-01

    This paper presents a low-cost and easy-to-implement image-based reconstruction technique for laboratory experiments, which results in a temporal description of the water surface topography. The distortion due to refraction of a known pattern, located below the water surface, is used to fit a low parameter surface model that describes the time-dependent and three-dimensional surface variation. Instead of finding the optimal water depth for characteristic points on the surface, the deformation of the entire pattern is compared to its original shape. This avoids the need for feature tracking adopted in similar techniques, which improves the robustness to suboptimal optical conditions and small-scale, high-frequency surface perturbations. Experimental validation, by comparison with water depth measurements using a level gauge and pressure sensor, proves sub-millimetre accuracy for smooth and steady surface shapes. Although such accuracy cannot be achieved in case of highly dynamic surface phenomena, the low-frequency and large-scale free surface oscillations can still be measured with a temporal and spatial resolution mostly limited by the available optical set-up. The technique is initially intended for periodic surface phenomena, but the results presented in this paper indicate that also irregular surface shapes can robustly be reconstructed. Therefore, the presented technique is a promising tool for other research applications that require non-intrusive, low-cost surface measurements while maintaining visual access to the water below the surface. The latter ensures that the suggested surface reconstruction is compatible with simultaneous image-based velocity measurements, enabling a detailed study of the flow.

  17. Chemical Flooding in Heavy-Oil Reservoirs: From Technical Investigation to Optimization Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Si Le Van

    2016-09-01

    rather than using a water slug in between. The results of the pre-evaluation show that two sequences of the ASP group have the highest NPV corresponding to the dissimilar applied oil prices. In the post-evaluation, the successful use of response surface methodology (RSM in the estimation and optimization procedures with coefficients of determination R2 greater than 0.97 shows that the project can possibly gain 4.47 $MM at a mean oil price of 46.5 $/bbl with the field scale of a quarter five-spot pattern. Further, with the novel assumption of normal distribution for the oil price variation, the chemical flooding sequence of concurrent alkali-surfactant-polymer injection with a buffering polymer solution is evaluated as the most feasible scheme owing to the achievement of the highest NPV at the highly possible oil price of 40–55 $/bbl compared to the other scheme.

  18. Modelling and analysis of tool wear and surface roughness in hard turning of AISI D2 steel using response surface methodology

    Directory of Open Access Journals (Sweden)

    M. Junaid Mir

    2018-01-01

    Full Text Available The present work deals with some machinability studies on tool wear and surface roughness, in finish hard turning of AISI D2 steel using PCBN, Mixed ceramic and coated carbide inserts. The machining experiments are conducted based on the response surface methodology (RSM. Combined effects of three cutting parameters viz., cutting speed, cutting time and tool hardness on the two performance outputs (i.e. VB and Ra, are explored employing the analysis of variance (ANOVA.The relationship(s between input variables and the response parameters are determined using a quadratic regression model. The results show that the tool wear was influenced principally by the cutting time and in the second level by the cutting tool hardness. On the other hand, cutting time was the dominant factor affecting workpiece surface roughness followed by cutting speed. Finally, the multiple response optimizations of tool wear and surface roughness were carried out using the desirability function approach (DFA.

  19. Biomimetic coating of organic polymers with a protein-functionalized layer of calcium phosphate: the surface properties of the carrier influence neither the coating characteristics nor the incorporation mechanism or release kinetics of the protein.

    Science.gov (United States)

    Wu, Gang; Liu, Yuelian; Iizuka, Tateyuki; Hunziker, Ernst B

    2010-12-01

    Polymers that are used in clinical practice as bone-defect-filling materials possess many essential qualities, such as moldability, mechanical strength and biodegradability, but they are neither osteoconductive nor osteoinductive. Osteoconductivity can be conferred by coating the material with a layer of calcium phosphate, which can be rendered osteoinductive by functionalizing it with an osteogenic agent. We wished to ascertain whether the morphological and physicochemical characteristics of unfunctionalized and bovine-serum-albumin (BSA)-functionalized calcium-phosphate coatings were influenced by the surface properties of polymeric carriers. The release kinetics of the protein were also investigated. Two sponge-like materials (Helistat® and Polyactive®) and two fibrous ones (Ethisorb™ and poly[lactic-co-glycolic acid]) were tested. The coating characteristics were evaluated using state-of-the-art methodologies. The release kinetics of BSA were monitored spectrophotometrically. The characteristics of the amorphous and the crystalline phases of the coatings were not influenced by either the surface chemistry or the surface geometry of the underlying polymer. The mechanism whereby BSA was incorporated into the crystalline layer and the rate of release of the truly incorporated depot were likewise unaffected by the nature of the polymeric carrier. Our biomimetic coating technique could be applied to either spongy or fibrous bone-defect-filling organic polymers, with a view to rendering them osteoconductive and osteoinductive.

  20. Improved Methodology for Monitoring Poly(amidoamine Dendrimers Surface Transformations and Product Quality by Ultra Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Chevelle A. Cason

    2008-01-01

    Full Text Available Ultra performance liquid chromatography (UPLC analysis was utilized for the first time as a methodology for monitoring poly(amidoamine (PAMAM dendrimer surface transformations and product quality. Results were compared to high-performance liquid chromatography (HPLC and were found to provide a vastly improved analytical method for the characterization of dendrimer polydispersity and variance in a typical surface modification. The application of UPLC increased the average number of theoretical plates by a factor of 7 and reduced retention times of analytes by 36%, while improving the resolution capability to discriminate surface variances in dendrimers. The new UPLC procedures were used to monitor surface modification of [core: ethylenediamine]; (G = 4; dendri-poly(amidoamine-(NH264 (i.e., [EDA]; (G4; dendri-PAMAM-(NH264 to produce biotinylated dendrimer conjugates. The enhanced sensitivity and efficiency of the UPLC analyses allowed resolution of biotin substituent levels and a better characterization of the targeted dendrimer conjugates compared to traditional HPLC methodology.

  1. Methodology for calculating the volume of condensate droplets on topographically modified, microgrooved surfaces.

    Science.gov (United States)

    Sommers, A D

    2011-05-03

    Liquid droplets on micropatterned surfaces consisting of parallel grooves tens of micrometers in width and depth are considered, and a method for calculating the droplet volume on these surfaces is presented. This model, which utilizes the elongated and parallel-sided nature of droplets condensed on these microgrooved surfaces, requires inputs from two droplet images at ϕ = 0° and ϕ = 90°--namely, the droplet major axis, minor axis, height, and two contact angles. In this method, a circular cross-sectional area is extruded the length of the droplet where the chord of the extruded circle is fixed by the width of the droplet. The maximum apparent contact angle is assumed to occur along the side of the droplet because of the surface energy barrier to wetting imposed by the grooves--a behavior that was observed experimentally. When applied to water droplets condensed onto a microgrooved aluminum surface, this method was shown to calculate the actual droplet volume to within 10% for 88% of the droplets analyzed. This method is useful for estimating the volume of retained droplets on topographically modified, anisotropic surfaces where both heat and mass transfer occur and the surface microchannels are aligned parallel to gravity to assist in condensate drainage.

  2. Mathematical Modelling and Optimization of Cutting Force, Tool Wear and Surface Roughness by Using Artificial Neural Network and Response Surface Methodology in Milling of Ti-6242S

    Directory of Open Access Journals (Sweden)

    Erol Kilickap

    2017-10-01

    Full Text Available In this paper, an experimental study was conducted to determine the effect of different cutting parameters such as cutting speed, feed rate, and depth of cut on cutting force, surface roughness, and tool wear in the milling of Ti-6242S alloy using the cemented carbide (WC end mills with a 10 mm diameter. Data obtained from experiments were defined both Artificial Neural Network (ANN and Response Surface Methodology (RSM. ANN trained network using Levenberg-Marquardt (LM and weights were trained. On the other hand, the mathematical models in RSM were created applying Box Behnken design. Values obtained from the ANN and the RSM was found to be very close to the data obtained from experimental studies. The lowest cutting force and surface roughness were obtained at high cutting speeds and low feed rate and depth of cut. The minimum tool wear was obtained at low cutting speed, feed rate, and depth of cut.

  3. Influence of manganese incorporation on structure, surface and As(III)/As(V) removal capacity of iron oxy-hydroxides

    Science.gov (United States)

    Tresintsi, Sofia; Simeonidis, Konstantinos; Mitrakas, Manassis

    2013-04-01

    Iron oxy-hydroxides are well defined As(V) adsorbents dominating in water treatment market. The main drawback of these adsorbents, as well as of all commercial one, is their significantly low adsorption capacity for As(III). A breakthrough for improving As(III) adsorption of iron oxy-hydroxides may come by the MnO2incorporation. However, MnO2 decreases the total arsenic capacity proportionally to its percentage since its efficiency for As(V) is much lower than that of an iron oxy-hydroxide. It is concluded that an ideal adsorbent capable for high and simultaneous As(III) and As(V) removal should be consisted of a binary Fe(III)-Mn(IV) oxy-hydroxide both efficient for As(III) oxidation, due to Mn(IV) presence, and capture of As(V) due to a high positively surface charge density. This work studies the optimum parameters at the synthesis of single Fe and binary Fe/Mn oxy-hydroxides in a continuous flow kilogram-scale production reactor through the precipitation of FeSO4 in the pH range 3-12, under intense oxidative conditions using H2O2/KMnO4, that maximize arsenic adsorption. The evaluation of their efficiency was based on its As(III) and As(V) adsorption capacity (Q10-index) at equilibrium concentration equal to drinking water regulation limit (Ce= 10 μg/L) in NSF challenge water. The pH of synthesis was found to decisively affect, the structure, surface configuration and Q10-index. As a result, both single Fe and binary Fe/Mn oxy-hydroxides prepared at pH 4, which consist of schwertmannite and Mn(IV)-feroxyhyte respectively, were qualified according to their highest Q10-index of 13±0.5 μg As(V)/ mg for a residual arsenic concentration of 10 μg/L at an equilibrium pH 7. The high surface charge and the activation of an ion-exchange mechanism between SO42- adsorbed in the Stern layer and arsenate ions were found to significantly contribute to the increased adsorption capacity. The Q10-index for As(III) of Fe/Mn adsorbent at equilibrium pH 7 was 6.7 μg/mg, which

  4. Optimization of cold-active protease production by the psychrophilic bacterium Colwellia sp. NJ341 with response surface methodology.

    Science.gov (United States)

    Wang, Quanfu; Hou, Yanhua; Xu, Zhong; Miao, Jinlai; Li, Guangyou

    2008-04-01

    Culture conditions were optimized for an extracellular cold-active protease production by the psychrophilic bacterium Colwellia sp. NJ341. Response surface methodology was applied for the most significant fermentation parameters (casein, citrate sodium, temperature and Tween-80) identified earlier by one-factor-at-a-time approach. A 2(4) full factorial central composite design was employed to determine the maximum protease production. Using this methodology, the quadratic regression model of producing cold-active protease was built and the optimal combinations of media constituents for maximum protease production (183.21 U/mL) were determined as casein 5.18 g/L, citrate sodium 3.84 g/L, temperature 7.96 degrees C, Tween-80 0.23 g/L. Protease production obtained experimentally coincident with the predicted value and the model was proven to be adequate.

  5. Development of a methodology for monthly forecasting of surface fires of Colombia's vegetation cover, an application to north Andean region

    International Nuclear Information System (INIS)

    Gonzalez Hernandez, Yolanda; Rangel CH, Jesus Orlando

    2004-01-01

    In the present article a methodology is presented for the forecasting of the monthly risk of surface fires of the vegetation cover in Colombia, based on the analysis of meteorological components and variables of climatic and anthropic variability involved in fire risks of the north Andean region. The methodology enables one to regionalize the country, with fire prediction purposes in mind, into ten sub-regions, in each one of which seven height levels are defined to make up separate regions of study. For each of these, a database is built to feed both the logistic regression models and the Poisson models, which identify the variables independent from, and/or associated with the presence or absence of fires

  6. Application of response surface methodology for degradation of methyl orange with TiO2 sol-gel sulphated Ti

    International Nuclear Information System (INIS)

    Del Angel S, M. T.; Garcia A, R.; Garcia A, P.; Lagunes G, L. M.; Cabrera C, E. G.

    2015-01-01

    In this work we report the implementation of the response surface methodology for the optimization of photo catalytic degradation of methyl orange dye (MO) using as photo catalyst sulphated TiO 2 prepared by sol-gel method. The variables studied were ph of the solution (3-11), catalyst concentration (0.1-1 g/L), and MO concentration (10-30 ppm). The effects of these parameters over the degradation of MO were evaluated according to a Box-Behnken design. The only crystal structure identified by X-ray diffraction was anatase phase. The optimum conditions for the photo catalytic degradation of MO according to the methodology applied were ph 6.0, 17.78 ppm MO concentration at each concentration level of the catalyst. (Author)

  7. Optimisation of warpage on thin shell plastic part using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

    Science.gov (United States)

    Asyirah, B. N.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

    2017-09-01

    In manufacturing a variety of parts, plastic injection moulding is widely use. The injection moulding process parameters have played important role that affects the product's quality and productivity. There are many approaches in minimising the warpage ans shrinkage such as artificial neural network, genetic algorithm, glowworm swarm optimisation and hybrid approaches are addressed. In this paper, a systematic methodology for determining a warpage and shrinkage in injection moulding process especially in thin shell plastic parts are presented. To identify the effects of the machining parameters on the warpage and shrinkage value, response surface methodology is applied. In thos study, a part of electronic night lamp are chosen as the model. Firstly, experimental design were used to determine the injection parameters on warpage for different thickness value. The software used to analyse the warpage is Autodesk Moldflow Insight (AMI) 2012.

  8. Artificial neural network and response surface methodology modeling in mass transfer parameters predictions during osmotic dehydration of Carica papaya L.

    Directory of Open Access Journals (Sweden)

    J. Prakash Maran

    2013-09-01

    Full Text Available In this study, a comparative approach was made between artificial neural network (ANN and response surface methodology (RSM to predict the mass transfer parameters of osmotic dehydration of papaya. The effects of process variables such as temperature, osmotic solution concentration and agitation speed on water loss, weight reduction, and solid gain during osmotic dehydration were investigated using a three-level three-factor Box-Behnken experimental design. Same design was utilized to train a feed-forward multilayered perceptron (MLP ANN with back-propagation algorithm. The predictive capabilities of the two methodologies were compared in terms of root mean square error (RMSE, mean absolute error (MAE, standard error of prediction (SEP, model predictive error (MPE, chi square statistic (χ2, and coefficient of determination (R2 based on the validation data set. The results showed that properly trained ANN model is found to be more accurate in prediction as compared to RSM model.

  9. Calculation of a solid/liquid surface tension: A methodological study

    Science.gov (United States)

    Dreher, T.; Lemarchand, C.; Soulard, L.; Bourasseau, E.; Malfreyt, P.; Pineau, N.

    2018-01-01

    The surface tension of a model solid/liquid interface constituted of a graphene sheet surrounded by liquid methane has been computed using molecular dynamics in the Kirkwood-Buff formalism. We show that contrary to the fluid/fluid case, the solid/liquid case can lead to different structurations of the first fluid layer, leading to significantly different values of surface tension. Therefore we present a statistical approach that consists in running a series of molecular simulations of similar systems with different initial conditions, leading to a distribution of surface tensions from which an average value and uncertainty can be extracted. Our results suggest that these distributions converge as the system size increases. Besides we show that surface tension is not particularly sensitive to the choice of the potential energy cutoff and that long-range corrections can be neglected contrary to what we observed in the liquid/vapour interfaces. We have not observed the previously reported commensurability effect.

  10. The Plumbing of Land Surface Models: Is Poor Performance a Result of Methodology or Data Quality?

    Science.gov (United States)

    Haughton, Ned; Abramowitz, Gab; Pitman, Andy J.; Or, Dani; Best, Martin J.; Johnson, Helen R.; Balsamo, Gianpaolo; Boone, Aaron; Cuntz, Matthais; Decharme, Bertrand; hide

    2016-01-01

    The PALS Land sUrface Model Benchmarking Evaluation pRoject (PLUMBER) illustrated the value of prescribing a priori performance targets in model intercomparisons. It showed that the performance of turbulent energy flux predictions from different land surface models, at a broad range of flux tower sites using common evaluation metrics, was on average worse than relatively simple empirical models. For sensible heat fluxes, all land surface models were outperformed by a linear regression against downward shortwave radiation. For latent heat flux, all land surface models were outperformed by a regression against downward shortwave, surface air temperature and relative humidity. These results are explored here in greater detail and possible causes are investigated. We examine whether particular metrics or sites unduly influence the collated results, whether results change according to time-scale aggregation and whether a lack of energy conservation in fluxtower data gives the empirical models an unfair advantage in the intercomparison. We demonstrate that energy conservation in the observational data is not responsible for these results. We also show that the partitioning between sensible and latent heat fluxes in LSMs, rather than the calculation of available energy, is the cause of the original findings. Finally, we present evidence suggesting that the nature of this partitioning problem is likely shared among all contributing LSMs. While we do not find a single candidate explanation forwhy land surface models perform poorly relative to empirical benchmarks in PLUMBER, we do exclude multiple possible explanations and provide guidance on where future research should focus.

  11. Optimization of meat level and processing conditions for development of chicken meat noodles using response surface methodology.

    Science.gov (United States)

    Khare, Anshul Kumar; Biswas, Asim Kumar; Balasubramanium, S; Chatli, Manish Kumar; Sahoo, Jhari

    2015-06-01

    Response surface methodology (RSM) is a mathematical and statistical technique for testing multiple process variables and their interactive, linear and quadratic effects, and useful in solving multivariable equations obtained from experiments simultaneously. In present study optimum meat level and processing conditions for development of shelf stable chicken meat noodles was determined using central composite design of response surface methodology (RSM). Effects of meat level (110-130 g); processing conditions such as steaming time (12-18 min) and drying time (7-9 h) on the water activity, yield, water absorption index, water solubility index, hardness, overall acceptability and total colour change of chicken noodles were investigated. The aim of present study was to optimize meat level and processing conditions for development of chicken noodles. The coefficients of determination, R(2) of all the response variables were higher than 0.8. Based on the response surface and superimposed plots, the optimum conditions such as 60 % meat level, 12 min steaming time and 9 h drying time for development of chicken noodles with desired sensory quality was obtained.

  12. [Optimization of flash-type extraction technology of alisol B 23-acetate from Alismatis Rhizoma by response surface methodology].

    Science.gov (United States)

    Wei, Ying-Chun; Yan, Ming; Yang, Jing; Liu, Jun-Chao; Yin, Hong-Mei; Wu, Yun; Sun, Yong-Cheng; Xiao, Wei

    2016-02-01

    Response surface methodology was used to optimize and obtain the optimal flash-type extraction technology of alisol B 23-acetate from Alismatis Rhizoma. With the extraction rate of alisol B 23-acetate as an indicator, single-factor test was used to investigate the effect of ethanol volume fraction, liquid-solid ratio, extraction times and extracting time on the extraction rate of alisol B 23-acetate.The results were combined with Box-Benhnken design and response surface analysis to optimize the technology parameters for extraction process of Alismatis Rhizoma and obtain the optimal flash-type extraction technology under the following conditions: ethanol volume fraction 80%, liquid-solid ratio 12∶1, extraction 4 times, 114 s/time. Flash-type extraction technology of alisol B 23-acetate by response surface methodology is stable, time-saving, efficient, and with the advantages of room temperature extraction and no component damage, so it can be used for massive production. Copyright© by the Chinese Pharmaceutical Association.

  13. Optimization of toxic biological compound adsorption from aqueous solution onto Silicon and Silicon carbide nanoparticles through response surface methodology.

    Science.gov (United States)

    Gupta, Vinod Kumar; Fakhri, Ali; Rashidi, Sahar; Ibrahim, Ahmed A; Asif, Mohammad; Agarwal, Shilpi

    2017-08-01

    The subject of this paper is removal of Aflatoxin B 1 as toxic biological compound adsorption onto Silicon (Si) and Silicon carbide (SiC) nanoparticles in aqueous matrices using Response surface methodology. The surface frame of Si and SiC nanoparticles were comminuted by XRD, TEM, SEM, and BET. Experiments were steered well-found by Box-Behnken plan (BBD). Experiments of batch method were performed to prognosticate the reaction equilibrium of Aflatoxin B 1 removal. The response surface methodological approach was used. In the agreeable perusal, effect of adsorbent dosage, temperature and pH on the Aflatoxin B 1 adsorption from aqueous matrices using Si and SiC nanoparticles has been investigated. The interplay of the changeables and their implication was studied using the analysis of variance. The optimum adsorbent dosage, pH, and temperature were obtained to be 0.04g, 9.0 and 278K, respectively and adsorption of Aflatoxin B 1 was 42.50 and 46.10mg/g for Si and SiC nanoparticles, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. A corrected model for static and dynamic electromechanical instability of narrow nanotweezers: Incorporation of size effect, surface layer and finite dimensions

    Science.gov (United States)

    Koochi, Ali; Hosseini-Toudeshky, Hossein; Abadyan, Mohamadreza

    2018-03-01

    Herein, a corrected theoretical model is proposed for modeling the static and dynamic behavior of electrostatically actuated narrow-width nanotweezers considering the correction due to finite dimensions, size dependency and surface energy. The Gurtin-Murdoch surface elasticity in conjunction with the modified couple stress theory is employed to consider the coupling effect of surface stresses and size phenomenon. In addition, the model accounts for the external force corrections by incorporating the impact of narrow width on the distribution of Casimir attraction, van der Waals (vdW) force and the fringing field effect. The proposed model is beneficial for the precise modeling of the narrow nanotweezers in nano-scale.

  15. Determination of Optimal Parameters for Diffusion Bonding of Semi-Solid Casting Aluminium Alloy by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kaewploy Somsak

    2015-01-01

    Full Text Available Liquid state welding techniques available are prone to gas porosity problems. To avoid this solid state bonding is usually an alternative of preference. Among solid state bonding techniques, diffusion bonding is often employed in aluminium alloy automotive parts welding in order to enhance their mechanical properties. However, there has been no standard procedure nor has there been any definitive criterion for judicious welding parameters setting. It is thus a matter of importance to find the set of optimal parameters for effective diffusion bonding. This work proposes the use of response surface methodology in determining such a set of optimal parameters. Response surface methodology is more efficient in dealing with complex process compared with other techniques available. There are two variations of response surface methodology. The one adopted in this work is the central composite design approach. This is because when the initial upper and lower bounds of the desired parameters are exceeded the central composite design approach is still capable of yielding the optimal values of the parameters that appear to be out of the initially preset range. Results from the experiments show that the pressing pressure and the holding time affect the tensile strength of jointing. The data obtained from the experiment fits well to a quadratic equation with high coefficient of determination (R2 = 94.21%. It is found that the optimal parameters in the process of jointing semi-solid casting aluminium alloy by using diffusion bonding are the pressing pressure of 2.06 MPa and 214 minutes of the holding time in order to achieve the highest tensile strength of 142.65 MPa

  16. OPTIMIZATION OF SURFACE RESISTIVITY AND RELATIVE PERMITTIVITY OF SILICONE RUBBER FOR HIGH VOLTAGE APPLICATION USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    N.N. Ali

    2017-06-01

    Full Text Available Silicone Rubber (SiR is considered as one of the most established insulator in High Voltage (HV industry. SiR possess a great function ability such as its lighter weight, great heat resistance and substantial electrical insulation properties. Dynamic research were performed all around the world in order to explore the unique insulating behavior of SiR but very little are done on the optimization of SiR in term of their processing parameters and formulation. In this work, four materials and processing factors were introduced; A: Alumina Trihydrate (ATH, B: Dicumyl-Peroxide (DCP, C: mixing speed and D: mixing time in order to analyze its contribution towards improving the surface resistivity and relative permittivity of SIR rubber. The factors range were set based on prior screening and are defined as; ATH (10 – 50 pphr, Dicumyl Peroxide (0.50 -1.50 pphr, speed of mixer (40 – 70 rpm and mixing period (5 – 10 mins which were then varied accordingly to produce an overall 19 samples of SiR blends. The testing results were analyzed using statistical Design of Experiment (DOE by applying two level full factorial from Design Expert Software (v10 to discover the inter-correlation between the factors studied and benefaction of each factor in improving both surface resistivity and relative permittivity responses of produced SiR blends. The model analysis on surface resistivity shows the coefficient of determination R2 value of 88.72% while the one for relative permittivity shows R2 value of 82.34 %. Combination of both dependent variables had yielded an optimization suggestion for SiR formulation and processing strategy of ATH: 50 pphr, DCP: 0.50 pphr, mixing speed: 70 rpm and mixing period: 10 mins with the desirability level of 0.835. The optimized formulation had resulted in the production of SiR blend with the characteristic of surface resistivity of 1.02039x10^14 Ω/sq and relative permittivity of 4.0231, respectively. In conclusion, it can be

  17. Optimisation of warpage on plastic injection moulding part using response surface methodology (RSM) and genetic algorithm method (GA)

    Science.gov (United States)

    Miza, A. T. N. A.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

    2017-09-01

    In this study, Computer Aided Engineering was used for injection moulding simulation. The method of Design of experiment (DOE) was utilize according to the Latin Square orthogonal array. The relationship between the injection moulding parameters and warpage were identify based on the experimental data that used. Response Surface Methodology (RSM) was used as to validate the model accuracy. Then, the RSM and GA method were combine as to examine the optimum injection moulding process parameter. Therefore the optimisation of injection moulding is largely improve and the result shown an increasing accuracy and also reliability. The propose method by combining RSM and GA method also contribute in minimising the warpage from occur.

  18. Solvent-free enzymatic synthesis of 1,3-diconjugated Linoleoyl Glycerol Optimized by Response Surface Methodology

    DEFF Research Database (Denmark)

    Guo, Zheng; Sun, Yan

    2004-01-01

    An operation mode with N2 bubbling under vacuum was employed for the solventfree synthesis of 1,3-diconjugated linoleoyl glycerol (1,3-dCLG) from conjugated linoleic acid (CLA) catalyzed by Novozym 435. The response surface methodology (RSM) was adopted for the optimization of the reaction...... conditions with five major factors (incubation time, temperature, enzyme load, substrate mole ratio, and system vacuum) and three responses (CLA conversion, 1,3-dCLG yield, and acyl migration). Two sets of optimal conditions were recommended. Validation of the RSM model was verified by the good agreement...

  19. Sensitivity analysis and development of calibration methodology for near-surface hydrogeology model of Laxemar

    International Nuclear Information System (INIS)

    Aneljung, Maria; Sassner, Mona; Gustafsson, Lars-Goeran

    2007-11-01

    This report describes modelling where the hydrological modelling system MIKE SHE has been used to describe surface hydrology, near-surface hydrogeology, advective transport mechanisms, and the contact between groundwater and surface water within the SKB site investigation area at Laxemar. In the MIKE SHE system, surface water flow is described with the one-dimensional modelling tool MIKE 11, which is fully and dynamically integrated with the groundwater flow module in MIKE SHE. In early 2008, a supplementary data set will be available and a process of updating, rebuilding and calibrating the MIKE SHE model based on this data set will start. Before the calibration on the new data begins, it is important to gather as much knowledge as possible on calibration methods, and to identify critical calibration parameters and areas within the model that require special attention. In this project, the MIKE SHE model has been further developed. The model area has been extended, and the present model also includes an updated bedrock model and a more detailed description of the surface stream network. The numerical model has been updated and optimized, especially regarding the modelling of evapotranspiration and the unsaturated zone, and the coupling between the surface stream network in MIKE 11 and the overland flow in MIKE SHE. An initial calibration has been made and a base case has been defined and evaluated. In connection with the calibration, the most important changes made in the model were the following: The evapotranspiration was reduced. The infiltration capacity was reduced. The hydraulic conductivities of the Quaternary deposits in the water-saturated part of the subsurface were reduced. Data from one surface water level monitoring station, four surface water discharge monitoring stations and 43 groundwater level monitoring stations (SSM series boreholes) have been used to evaluate and calibrate the model. The base case simulations showed a reasonable agreement

  20. Hydrothermal pretreatment of sugarcane bagasse using response surface methodology improves digestibility and ethanol production by SSF

    Science.gov (United States)

    Sugarcane bagasse was characterized as a feedstock for production of ethanol using hydrothermal pretreatment. Reaction temperature and time were varied between 160-200 deg C and 5-20 min, respectively, using a response surface experimental design. The liquid fraction was analyzed for soluble carbohy...

  1. Adsorptive removal of crystal violet dye by a local clay and process optimization by response surface methodology

    Science.gov (United States)

    Loqman, Amal; El Bali, Brahim; Lützenkirchen, Johannes; Weidler, Peter G.; Kherbeche, Abdelhak

    2017-11-01

    The current study relates to the removal of a dye [crystal violet (CV)] from aqueous solutions through batch adsorption experiment onto a local clay from Morocco. The clay was characterized by X-ray diffraction, IR spectroscopy, X-ray fluorescence, scanning electron microscope, Brunauer-Emmett-Teller analysis and Fraunhofer diffraction method. The influence of independent variables on the removal efficiency was determined and optimized by response surface methodology using the Box-Behnken surface statistical design. The model predicted maximum adsorption of 81.62% under the optimum conditions of operational parameters (125 mg L-1 initial dye concentration, 2.5 g L-1 adsorbent dose and time of 43 min). Practically, the removal ranges in 27.4-95.3%.

  2. High-directional light source using photon recycling with a retro-reflective Dome incorporated with a textured LED die surface.

    Science.gov (United States)

    Sun, Ching-Cherng; Chung, Shuang-Chao; Yang, Shuang-Hao; Yu, Yeh-Wei; Chien, Wei-Ting; Chen, Huang-Kuen; Chen, Shih-Peng

    2013-07-29

    This paper demonstrates a novel retro-reflective dome that enhances the directionality of a light emitting diode (LED) by recycling photons reflected by a textured LED die surface. A simulation model is developed to describe both the photon recycling process within the dome and the role of specific pyramid patterns on the top surface of the LED die. Advanced simulations showed that a perfectly polished surface with 100% reflectivity potentially enhances the directionality of the dome by 340%, 250%, and 240% using reflective domes with 10°, 20°, and 30° light cones, respectively. In the experiment, the directionality of the domes exhibiting surface imperfections is enhanced by approximately 160%, 150%, and 130% using 10°, 20°, and 30° light cones, respectively. By incorporating a textured top surface on the LED die, the proposed dome effectively increases the directionality of the LED light source.

  3. A new green methodology for surface modification of diatomite filler in elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Lamastra, F.R. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Mori, S.; Cherubini, V. [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Department of Enterprise Engineering, University of Rome ' Tor Vergata' , Via del Politecnico 1, 00133, Rome (Italy); Scarselli, M. [Department of Physics, University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133, Rome (Italy); Nanni, F., E-mail: fnanni@ing.uniroma2.it [Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit Roma Tor Vergata, Via del Politecnico 1, 00133, Rome (Italy); Department of Enterprise Engineering, University of Rome ' Tor Vergata' , Via del Politecnico 1, 00133, Rome (Italy)

    2017-06-15

    In this work a new, simple and green protocol to introduce a limited content of silanol groups on the surface of an hydrophobic diatomite, in order to be slightly hydrophilic and susceptible to be silanized by bifunctional, sulfur-containing organosilanes for rubber applications, is proposed. The chemical modification was carried out at 85 °C in a solution of H{sub 2}O:NaOH:H{sub 2}O{sub 2}. The modified diatomite was then silanized with bis(triethoxysilylpropyl) disulfide by a procedure that does not involve toxic solvent. Morphological features and elemental composition of diatomite were investigated by Field emission scanning electron microscopy coupled with Energy dispersive X-ray spectroscopy. The surface modification and silanization process were assessed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Diatomite was composed by micrometric frustules from different diatom species with pore size ranging from 25 nm to 1 μm. The spectroscopic characterizations confirmed the surface modification of diatomite with some silanols that acted as sites for silanization reaction. The silanized diatomite and the untreated one were used as filler in unvulcanized solvent-cast SBR films in order to verify that the modification does not negatively affect the polymer/filler interface and as consequence the mechanical properties. Mechanical properties of the realized samples were assessed by uniaxial tensile tests. Films filled with 10 wt% of diatomite (untreated or silanized) showed an increase of Elastic Modulus about of 50% and a decrease of the strain at break with respect to SBR samples, while the tensile strength was not significantly affected by the diatomite addition. SEM images of fracture surfaces of tested specimens showed a fine dispersion of both untreated and silanized diatomite in the polymeric matrix and the achieving of a good interfacial adhesion SBR/fillers. The silanized diatomite, as it is potentially able to bind

  4. Nutrients interaction investigation to improve Monascus purpureus FTC5391 growth rate using Response Surface Methodology and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Mohamad, R.

    2013-01-01

    Full Text Available Aims: Two vital factors, certain environmental conditions and nutrients as a source of energy are entailed for successful growth and reproduction of microorganisms. Manipulation of nutritional requirement is the simplest and most effectual strategy to stimulate and enhance the activity of microorganisms. Methodology and Results: In this study, response surface methodology (RSM and artificial neural network (ANN were employed to optimize the carbon and nitrogen sources in order to improve growth rate of Monascus purpureus FTC5391,a new local isolate. The best models for optimization of growth rate were a multilayer full feed-forward incremental back propagation network, and a modified response surface model using backward elimination. The optimum condition for cell mass production was: sucrose 2.5%, yeast extract 0.045%, casamino acid 0.275%, sodium nitrate 0.48%, potato starch 0.045%, dextrose 1%, potassium nitrate 0.57%. The experimental cell mass production using this optimal condition was 21 mg/plate/12days, which was 2.2-fold higher than the standard condition (sucrose 5%, yeast extract 0.15%, casamino acid 0.25%, sodium nitrate 0.3%, potato starch 0.2%, dextrose 1%, potassium nitrate 0.3%. Conclusion, significance and impact of study: The results of RSM and ANN showed that all carbon and nitrogen sources tested had significant effect on growth rate (P-value < 0.05. In addition the use of RSM and ANN alongside each other provided a proper growth prediction model.

  5. Application of response surface methodology to optimise supercritical carbon dioxide extraction of volatile compounds from Crocus sativus.

    Science.gov (United States)

    Shao, Qingsong; Huang, Yuqiu; Zhou, Aicun; Guo, Haipeng; Zhang, Ailian; Wang, Yong

    2014-05-01

    Crocus sativus has been used as a traditional Chinese medicine for a long time. The volatile compounds of C. sativus appear biologically active and may act as antioxidants as well as anticonvulsants, antidepressants and antitumour agents. In order to obtain the highest possible yield of essential oils from C. sativus, response surface methodology was employed to optimise the conditions of supercritical fluid carbon dioxide extraction of the volatile compounds from C. sativus. Four factorswere investigated: temperature, pressure, extraction time and carbon dioxide flow rate. Furthermore, the chemical compositions of the volatile compounds extracted by supercritical fluid extraction were compared with those obtained by hydro-distillation and Soxhlet extraction. The optimum extraction conditions were found to be: optimised temperature 44.9°C, pressure 34.9 MPa, extraction time 150.2 min and CO₂ flow rate 10.1 L h⁻¹. Under these conditions, the mean extraction yield was 10.94 g kg⁻¹. The volatile compounds extracted by supercritical fluid extraction and Soxhlet extraction contained a large amount of unsaturated fatty acids. Response surface methodology was successfully applied for supercritical fluid CO₂ extraction optimisation of the volatile compounds from C. sativus. The study showed that pressure and CO₂ flow rate had significant effect on volatile compounds yield produced by supercritical fluid extraction. This study is beneficial for the further research operating on a large scale. © 2013 Society of Chemical Industry.

  6. Modeling of the effect of freezer conditions on the hardness of ice cream using response surface methodology.

    Science.gov (United States)

    Inoue, K; Ochi, H; Habara, K; Taketsuka, M; Saito, H; Ichihashi, N; Iwatsuki, K

    2009-12-01

    The effect of conventional continuous freezer parameters [mix flow (L/h), overrun (%), drawing temperature ( degrees C), cylinder pressure (kPa), and dasher speed (rpm)] on the hardness of ice cream under varying measured temperatures (-5, -10, and -15 degrees C) was investigated systematically using response surface methodology (central composite face-centered design), and the relationships were expressed as statistical models. The range (maximum and minimum values) of each freezer parameter was set according to the actual capability of the conventional freezer and applicability to the manufacturing process. Hardness was measured using a penetrometer. These models showed that overrun and drawing temperature had significant effects on hardness. The models can be used to optimize freezer conditions to make ice cream of the least possible hardness under the highest overrun (120%) and a drawing temperature of approximately -5.5 degrees C (slightly warmer than the lowest drawing temperature of -6.5 degrees C) within the range of this study. With reference to the structural elements of the ice cream, we suggest that the volume of overrun and ice crystal content, ice crystal size, and fat globule destabilization affect the hardness of ice cream. In addition, the combination of a simple instrumental parameter and response surface methodology allows us to show the relation between freezer conditions and one of the most important properties-hardness-visually and quantitatively on the practical level.

  7. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef

    2011-06-01

    Full Text Available Abstract Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil and vegetables (jojoba which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C, the enzyme concentration (33.34-300 IU/mL, the alcohol/palm stearin molar ratio (3-7 mol/mol and the substrate concentration (0.06-0.34 g/mL on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.

  8. Ultrasonic vibration-assisted pelleting of wheat straw: a predictive model for energy consumption using response surface methodology.

    Science.gov (United States)

    Song, Xiaoxu; Zhang, Meng; Pei, Z J; Wang, Donghai

    2014-01-01

    Cellulosic biomass can be used as a feedstock for biofuel manufacturing. Pelleting of cellulosic biomass can increase its bulk density and thus improve its storability and reduce the feedstock transportation costs. Ultrasonic vibration-assisted (UV-A) pelleting can produce biomass pellets whose density is comparable to that processed by traditional pelleting methods (e.g. extruding, briquetting, and rolling). This study applied response surface methodology to the development of a predictive model for the energy consumption in UV-A pelleting of wheat straw. Effects of pelleting pressure, ultrasonic power, sieve size, and pellet weight were investigated. This study also optimized the process parameters to minimize the energy consumption in UV-A pelleting using response surface methodology. Optimal conditions to minimize the energy consumption were the following: ultrasonic power at 20%, sieve size at 4 mm, and pellet weight at 1g, and the minimum energy consumption was 2.54 Wh. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Production of laccase from Pleurotus florida NCIM 1243 using Plackett-Burman design and response surface methodology.

    Science.gov (United States)

    Palvannan, T; Sathishkumar, P

    2010-08-01

    Statistically-based experimental designs were applied to optimize the fermentation for the production of laccase by Pleurotus florida NCIM 1243. Eleven components were screened for their significant effect on laccase production using Plackett-Burman factorial design. Glucose (carbon source), asparagine (nitrogen source), CuSO(4)(inducer) and incubation period were found to have highest positive influence on the laccase production. The combined effect of these factors on laccase production was studied using central composite design of Response surface methodology. The optimal point of variables for maximum laccase production using Response surface methodology are glucose (15.21 g/l), asparagine (6.40 g/l), CuSO(4) (91.78 microM) and incubation period (178.55 h), respectively. The maximum enzyme activity predicted by the model was 5.0 U/ml which was in perfect agreement with the actual experimental value (4.8 U/ml). Further, partially purified laccase from the optimized cultural condition was used for the decolorization of reactive dyes, Reactive Blue 198 and Reactive Red 35. Copyright 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

  10. Development of Phaleria macrocarpa (Scheff.) Boerl Fruits Using Response Surface Methodology Focused on Phenolics, Flavonoids and Antioxidant Properties.

    Science.gov (United States)

    Mohamed Mahzir, Khurul Ain; Abd Gani, Siti Salwa; Hasanah Zaidan, Uswatun; Halmi, Mohd Izuan Effendi

    2018-03-22

    In this study, the optimal conditions for the extraction of antioxidants from the Buah Mahkota Dewa fruit ( Phaleria macrocarpa) was determined by using Response Surface Methodology (RSM). The optimisation was applied using a Central Composite Design (CCD) to investigate the effect of three independent variables, namely extraction temperature (°C), extraction time (minutes) and extraction solvent to-feed ratio (% v / v ) on four responses: free radical scavenging activity (DPPH), ferric ion reducing power assay (FRAP), total phenolic content (TPC) and total flavonoid content (TFC). The optimal conditions for the antioxidants extraction were found to be 64 °C extraction temperature, 66 min extraction time and 75% v / v solvent to-feed ratio giving the highest percentage yields of DPPH, FRAP, TPC and TFC of 86.85%, 7.47%, 292.86 mg/g and 3.22 mg/g, respectively. Moreover, the data were subjected to Response Surface Methodology (RSM) and the results showed that the polynomial equations for all models were significant, did not show lack of fit, and presented adjusted determination coefficients ( R ²) above 99%, proving that the yield of phenolic, flavonoid and antioxidants activities obtained experimentally were close to the predicted values and the suitability of the model employed in RSM to optimise the extraction conditions. Hence, in this study, the fruit from P. macrocarpa could be considered to have strong antioxidant ability and can be used in various cosmeceutical or medicinal applications.

  11. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: optimization by response surface methodology.

    Science.gov (United States)

    Sellami, Mohamed; Aissa, Imen; Frikha, Fakher; Gargouri, Youssef; Miled, Nabil

    2011-06-17

    Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50 °C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30 °C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters. © 2011 Sellami et al; licensee BioMed Central Ltd.

  12. Optimization of the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 by response surface methodology

    Directory of Open Access Journals (Sweden)

    Panagiota-Yiolanda Stergiou

    2014-06-01

    Full Text Available The aim of this work was to study the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 using optimized nutritional and cultural conditions in a complex yeast medium under aerobic batch fermentation. By applying the conventional "one-variable-at-a-time" approach and the response surface methodology, the effect of four fermentation parameters (type of carbon source, initial culture pH, temperature, and incubation time on the growth and α-amylase production was evaluated. The production of α-amylase during 60 h of fermentation increased 13-fold under optimized conditions (1% starch, pH 6.0, 30ºC in comparison to the conventional optimization method. The initial pH value of 6.13 and temperature of 30.3ºC were optimal conditions by the response surface methodology, leading to further improvement (up to 13-fold in the production of extracellular α-amylase. These results constituted first evidence that K. marxianus could be potentially used as an effective source of extracellular α-amylase.

  13. Analysis of parameter and interaction between parameter of the microwave assisted transesterification process of coconut oil using response surface methodology

    Science.gov (United States)

    Hidayanti, Nur; Suryanto, A.; Qadariyah, L.; Prihatini, P.; Mahfud, Mahfud

    2015-12-01

    A simple batch process was designed for the transesterification of coconut oil to alkyl esters using microwave assisted method. The product with yield above 93.225% of alkyl ester is called the biodiesel fuel. Response surface methodology was used to design the experiment and obtain the maximum possible yield of biodiesel in the microwave-assisted reaction from coconut oil with KOH as the catalyst. The results showed that the time reaction and concentration of KOH catalyst have significant effects on yield of alkyl ester. Based on the response surface methodology using the selected operating conditions, the time of reaction and concentration of KOH catalyst in transesterification process were 150 second and 0.25%w/w, respectively. The largest predicted and experimental yield of alkyl esters (biodiesel) under the optimal conditions are 101.385% and 93.225%, respectively. Our findings confirmed the successful development of process for the transesterification reaction of coconut oil by microwave-assisted heating, which is effective and time-saving for alkyl ester production.

  14. Synthesis of biocompatible and highly photoluminescent nitrogen doped carbon dots from lime: Analytical applications and optimization using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Barati, Ali [Faculty of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan (Iran, Islamic Republic of); Shamsipur, Mojtaba, E-mail: mshamsipur@yahoo.com [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Arkan, Elham [Nano Drug Delivery Research Center Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Hosseinzadeh, Leila [Novel Drug Delivery Research Center, Faculty of Pharmacy, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Abdollahi, Hamid, E-mail: abd@iasbs.ac.ir [Faculty of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan (Iran, Islamic Republic of)

    2015-02-01

    Herein, a facile hydrothermal treatment of lime juice to prepare biocompatible nitrogen-doped carbon quantum dots (N-CQDs) in the presence of ammonium bicarbonate as a nitrogen source has been presented. The resulting N-CQDs exhibited excitation and pH independent emission behavior; with the quantum yield (QY) up to 40%, which was several times greater than the corresponding value for CQDs with no added nitrogen source. The N-CQDs were applied as a fluorescent probe for the sensitive and selective detection of Hg{sup 2+} ions with a detection limit of 14 nM. Moreover, the cellular uptake and cytotoxicity of N-CQDs at different concentration ranges from 0.0 to 0.8 mg/ml were investigated by using PC12 cells as a model system. Response surface methodology was used for optimization and systematic investigation of the main variables that influence the QY, including reaction time, reaction temperature, and ammonium bicarbonate weight. - Highlights: • High fluorescent N-doped CQDs from lime juice have been prepared. • Response surface methodology was used to optimize and model the main factors. • N-doped CQDs were used in the selective and sensitive detection of Hg(II). • The biocompatibility of prepared N-doped CQDs was conformed using PC12 cells.

  15. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Science.gov (United States)

    2011-01-01

    Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters. PMID:21682865

  16. Application of Response Surface Methodology (RSM) for wastewater of hospital by using electrocoagulation

    Science.gov (United States)

    Murdani; Jakfar; Ekawati, D.; Nadira, R.; Darmadi

    2018-04-01

    Hospital wastewater is a source of potential environmental contamination. Therefore, the waste water needs to be treated before it is discharged into the landfill. Various research methods have been used to treat hospital wastewater. However, some methods that have been implemented have not achieved the effluent standards for hospitals that have been set by the government. The experiment was conducted by an electrochemical method is electrolysis using aluminum electrodes with independent variable is the voltage, contact time and concentration of electrolytes. The response optimization using response surface with optimum conditions obtained by the contact time of 34.26 min, voltage 12 V, concentration electrolyte 0.38 M can decrease of COD 65.039%. The model recommended by the response surface for the three variables, namely quadratic response.

  17. Sensitivity analysis and development of calibration methodology for near-surface hydrogeology model of Forsmark

    International Nuclear Information System (INIS)

    Aneljung, Maria; Gustafsson, Lars-Goeran

    2007-04-01

    The hydrological modelling system MIKE SHE has been used to describe near-surface groundwater flow, transport mechanisms and the contact between ground- and surface water at the Forsmark site. The surface water system at Forsmark is described with the 1D modelling tool MIKE 11, which is fully and dynamically integrated with MIKE SHE. In spring 2007, a new data freeze will be available and a process of updating, rebuilding and calibrating the MIKE SHE model will start, based on the latest data set. Prior to this, it is important to gather as much knowledge as possible on calibration methods and to define critical calibration parameters and areas within the model. In this project, an optimization of the numerical description and an initial calibration of the MIKE SHE model has been made, and an updated base case has been defined. Data from 5 surface water level monitoring stations, 4 surface water discharge monitoring stations and 32 groundwater level monitoring stations (SFM soil boreholes) has been used for model calibration and evaluation. The base case simulations generally show a good agreement between calculated and measured water levels and discharges, indicating that the total runoff from the area is well described by the model. Moreover, with two exceptions (SFM0012 and SFM0022) the base case results show very good agreement between calculated and measured groundwater head elevations for boreholes installed below lakes. The model also shows a reasonably good agreement between calculated and measured groundwater head elevations or depths to phreatic surfaces in many other points. The following major types of calculation-measurement differences can be noted: Differences in groundwater level amplitudes due to transpiration processes. Differences in absolute mean groundwater head, due to differences between borehole casing levels and the interpolated DEM. Differences in absolute mean head elevations, due to local errors in hydraulic conductivity values

  18. Adsorption, Desorption, Surface Diffusion, Lattice Defect Formation, and Kink Incorporation Processes of Particles on Growth Interfaces of Colloidal Crystals with Attractive Interactions

    Directory of Open Access Journals (Sweden)

    Yoshihisa Suzuki

    2016-07-01

    Full Text Available Good model systems are required in order to understand crystal growth processes because, in many cases, precise incorporation processes of atoms or molecules cannot be visualized easily at the atomic or molecular level. Using a transmission-type optical microscope, we have successfully observed in situ adsorption, desorption, surface diffusion, lattice defect formation, and kink incorporation of particles on growth interfaces of colloidal crystals of polystyrene particles in aqueous sodium polyacrylate solutions. Precise surface transportation and kink incorporation processes of the particles into the colloidal crystals with attractive interactions were observed in situ at the particle level. In particular, contrary to the conventional expectations, the diffusion of particles along steps around a two-dimensional island of the growth interface was not the main route for kink incorporation. This is probably due to the number of bonds between adsorbed particles and particles in a crystal; the number exceeds the limit at which a particle easily exchanges its position to the adjacent one along the step. We also found novel desorption processes of particles from steps to terraces, attributing them to the assistance of attractive forces from additionally adsorbing particles to the particles on the steps.

  19. Lanthanum oxide nanorods for enhanced phosphate removal from sewage: A response surface methodology study.

    Science.gov (United States)

    Fang, Liping; Wu, Baile; Chan, Julie K M; Lo, Irene M C

    2018-02-01

    Lanthanum-based adsorbents are ideal candidates for phosphate removal because of their excellent affinity to phosphate. However, their application in the removal of trace-levels of phosphate from sewage is still unsatisfactory due to the limited adsorption capacity and inadequate optimization of the operational parameters. To overcome these drawbacks, we have developed a novel lanthanum hydroxide (LH), using a facile precipitation and hydrothermal process that involves a nanorod-like structure with the lengths ranging from 124 to 1700 nm, depending on the La/OH molar ratio. The phosphate adsorption capacity of the developed LH is up to 170.1 mg-P g -1 in synthetic water, while a slightly lower adsorption capacity of 111.1 mg-P g -1 is observed in a sewage sample. A polynominal model consisting of three variables (i.e. dosage, reaction time and initial phosphate concentration) for predicting efficiency of phosphate removal has been successfully developed using a face-centred central composite design (CCD)-based methodology. The results also suggest a strong interactive effect of the dosage with the phosphate concentration, and reaction time, which can significantly affect the optimization of the phosphate removal by LH. Both X-ray photoelectron spectroscopy and X-ray diffraction studies indicate that the inner sphere complexation of phosphate with LH is probably the major mechanism governing phosphate removal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Optimization of a protective medium for enhancing the viability of freeze-dried Bacillus amyloliquefaciens B1408 based on response surface methodology.

    Science.gov (United States)

    Han, Lingjuan; Pu, Taixun; Wang, Xi; Liu, Beiling; Wang, Yonghong; Feng, Juntao; Zhang, Xing

    2018-02-16

    Response surface methodology (RSM) is a commonly used system to optimize cryoprotectants of biocontrol strains when they are subjected to preparations. Various kinds of cryoprotectants and centrifugal conditions were tested to improve the survival of biocontrol agents after freeze-drying. To determine the optimum levels of incorporation of three cryoprotectants (glucose, trehalose and xylitol) in the freeze-drying process of strain Bacillus amyloliquefaciens B1408, a range of experiments based on Box-Behnken Design (BBD) were conducted. The results indicated that the suitable centrifugation conditions were 5000 r/min,10 min and the optimum concentrations of cryoprotectants were glucose 1.00%, trehalose 4.74% and xylitol 1.45%. The proven survival rate of cells after freeze-drying was 91.24%. These results convincingly demonstrated that freeze-drying could be used to preparation of biocontrol strain B1408. This study provides a theoretical basis for commercial possibilities and formulation development. Copyright © 2018. Published by Elsevier Inc.

  1. [Optimization of biocontrol agent Burkholderia pyrrocinia strain JK-SH007 fermentation by response surface methodology].

    Science.gov (United States)

    Li, Hao; Ren, Jiahong; Ye, Jianren

    2013-02-01

    In order to improve ferment efficiency of biocontrol agent Burkholderia pyrrocinia JK-SH007, the fermentation conditions of this strain were optimized. The optimal fermentation conditions were corn steep liquor (13.88 g/L) and glucose (3.37 g/L) by screening test, steepest ascent experiments and response surface analysis. The results showed that the cell density of JK-SH007 (1.18 x 10(9) CFU/mL) increased 1.35 times than before, and there was a 28.84% increase in antifungal activity.

  2. ISAM news. International programme on implementation of safety assessment methodologies for near surface disposal facilities for radioactive waste (ISAM 1997-1999)

    International Nuclear Information System (INIS)

    Torres, Carlos

    1996-01-01

    The scope of the programme will be the scientific and technical aspects related to the long term safety assessment of near disposal facilities. The primary focus of ISAM will be on the methodological aspects of safety assessment with emphasis on the practical application of these methodologies. Furthermore, practical application is necessary for for a thorough understanding of safety assessment methodologies. The programme will address important methodological issues associated with long term safety assessment of near surface disposal systems. At least three important areas will be covered: (1) scenario generation and justification; (2) modelling, data and tools; and (3) analysis of results and confidence building

  3. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sudarjanto, Gatut [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller-Lehmann, Beatrice [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia); Keller, Jurg [Advanced Wastewater Management Centre, The University of Queensland, Qld 4072 (Australia)]. E-mail: j.keller@awmc.uq.edu.au

    2006-11-02

    The integrated chemical-biological degradation combining advanced oxidation by UV/H{sub 2}O{sub 2} followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H{sub 2}O{sub 2}/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required.

  4. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    International Nuclear Information System (INIS)

    Sudarjanto, Gatut; Keller-Lehmann, Beatrice; Keller, Jurg

    2006-01-01

    The integrated chemical-biological degradation combining advanced oxidation by UV/H 2 O 2 followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H 2 O 2 /L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required

  5. Determination of injection molding process windows for optical lenses using response surface methodology.

    Science.gov (United States)

    Tsai, Kuo-Ming; Wang, He-Yi

    2014-08-20

    This study focuses on injection molding process window determination for obtaining optimal imaging optical properties, astigmatism, coma, and spherical aberration using plastic lenses. The Taguchi experimental method was first used to identify the optimized combination of parameters and significant factors affecting the imaging optical properties of the lens. Full factorial experiments were then implemented based on the significant factors to build the response surface models. The injection molding process windows for lenses with optimized optical properties were determined based on the surface models, and confirmation experiments were performed to verify their validity. The results indicated that the significant factors affecting the optical properties of lenses are mold temperature, melt temperature, and cooling time. According to experimental data for the significant factors, the oblique ovals for different optical properties on the injection molding process windows based on melt temperature and cooling time can be obtained using the curve fitting approach. The confirmation experiments revealed that the average errors for astigmatism, coma, and spherical aberration are 3.44%, 5.62%, and 5.69%, respectively. The results indicated that the process windows proposed are highly reliable.

  6. Efficiency enhancement of fluorescence blue organic light-emitting diodes by incorporating Ag nanoparticles layers due to a localized surface plasmon

    Science.gov (United States)

    Nam, Minwoo; Chung, Nak-Kwan; Shim, Seob; Yun, Ju-Young; Kim, Jin-Tae; Pyo, Sung Gyu

    2017-09-01

    Enhanced electroluminescence in blue organic light-emitting diodes (OLEDs) is obtained by incorporating Ag nanoparticles (NPs) into hole injection layer of poly(3,4- ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS). The absorption peak of the localized surface plasmons (LSPs) introduced by the 60 nm Ag NPs matches the emission wavelength of the blue OLEDs were matched at wavelength of 442 nm. In addition, to maximize their coupling and to prevent the quenching of the emission, the distance between surface plasmons (SPs) around NPs and organic fluorophores is optimized. Finally, the emission intensity and the current efficiency of diode with Ag NPs were increased by 19% and 18%, respectively.

  7. Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

    Directory of Open Access Journals (Sweden)

    Soheil Bechara

    2017-01-01

    Full Text Available Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible, 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible: 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based. A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes.

  8. Fixed Full Arches Supported by Tapered Implants with Knife-Edge Thread Design and Nanostructured, Calcium-Incorporated Surface: A Short-Term Prospective Clinical Study

    Science.gov (United States)

    Bechara, Soheil; Lukosiunas, Algirdas; Kubilius, Ricardas

    2017-01-01

    Purpose. To evaluate implant survival, peri-implant bone loss, and complications affecting fixed full-arch (FFA) restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface. Methods. Between January 2013 and December 2015, all patients referred for implant-supported FFA restorations were considered for enrollment in this study. All patients received implants with a knife-edge thread design and nanostructured calcium-incorporated surface (Anyridge®, Megagen, South Korea) were restored with FFA restorations and enrolled in a recall program. The final outcomes were implant survival, peri-implant bone loss, biologic/prosthetic complications, and “complication-free” survival of restorations. Results. Twenty-four patients were selected. Overall, 215 implants were inserted (130 maxilla, 85 mandible), 144 in extraction sockets and 71 in healed ridges. Thirty-six FFAs were delivered (21 maxilla, 15 mandible): 27 were immediately loaded and 9 were conventionally loaded. The follow-up ranged from 1 to 3 years. Two fixtures failed, yielding an implant survival rate of 95.9% (patient-based). A few complications were registered, for a “complication-free” survival of restorations of 88.9%. Conclusions. FFA restorations supported by implants with a knife-edge thread design and nanostructured, calcium-incorporated surface are successful in the short term, with high survival and low complication rates; long-term studies are needed to confirm these outcomes. PMID:28246595

  9. Optimization of Reactive Blue 21 removal by Nanoscale Zero-Valent Iron using response surface methodology

    Directory of Open Access Journals (Sweden)

    Mahmood Reza Sohrabi

    2016-07-01

    Full Text Available Since Reactive Blue 21 (RB21 is one of the dye compounds which is harmful to human life, a simple and sensitive method to remove this pollutant from wastewater is using Nano Zero-Valent Iron (NZVI catalyst. In this paper, a Central Composite Rotatable Design (CCRD was employed for response surface modeling to optimize experimental conditions of the RB21 removal from aqueous solution. The significance and adequacy of the model were analyzed using analysis of variance (ANOVA. Four independent variables—including catalyst amount (0.1–0.9 g, pH (3.5–9.5, removal time (30–150 s and dye concentration (10–50 mg/L—were transformed to coded values and consequently second order quadratic model was built to predict the responses. The result showed that under optimized experimental conditions the removal of RB21 was over 95%.

  10. Response Surface Methodology for Design of Porous Hollow Sphere Thermal Insulator

    Science.gov (United States)

    Shohani, Nazanin; Pourmahdian, Saeed; Shirkavand Hadavand, Behzad

    2017-11-01

    In this study, response surface method is used for synthesizing polystyrene (PS) as sacrificial templates and optimizing the particle size. Three factors of initiator, stabilizer concentration and also stirring rate were selected as variable factors. Then, three different concentration of tetraethyl orthosilicate (TEOS) added to reaction media and core-shell structure with PS core and silica shell was developed. Finally, core-shell structure was changed to hollow silica sphere for using as thermal insulator. We observed that increased initiator concentration caused to larger PS particles, increase the stirring rate caused the smaller PS and also with increased the stabilizer concentration obtained that particle size decrease then after 2.5% began to increase. Also the optimum amount of TEOS was found.

  11. [Preparation of red mud loaded Co catalysts: optimization using response surface methodology (RSM) and activity evaluation].

    Science.gov (United States)

    Li, Hua-Nan; Xu, Bing-Bing; Qi, Fei; Sun, De-Zhi

    2013-11-01

    The removal efficiency of catalytic ozonation of bezafibrate (BZF) by red mud loaded Co catalysts (Co/RM) was used as the index value in statistical experimental designs. The most important factors influencing BZF degradation (P removal efficiency was 71.29% as calculated by predictive value and a maximum removal efficiency of 70.74% was actually achieved. The experiment data was very close to the predictive value and the deviation was 1% (component formed on the surface of RM by the addition of cobalt into red mud, enhanced the catalytic activity. Moreover, the dissolved metal concentration in the solution for catalytic ozonation of BZF degradation by RM or Co/RM was determined by ICP-OES. The results showed that for both catalysts there was no leaching of catalytic active components into the solution, which could suggest that the two catalysts were safe and could have certain application prospect.

  12. Flavonoids Extraction from Taraxacum officinale (Dandelion: Optimisation Using Response Surface Methodology and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Zongxi Sun

    2014-01-01

    Full Text Available The Box-Behnken design combined with response surface method was employed to optimize ultrasonic-assisted extraction of flavonoids from Taraxacum officinale. The optimized results showed that the highest extraction yield with ultrasonic-assisted extraction could reach 2.62% using 39.6% (v/v ethanol and 59.5 : 1 (mL/g liquid-solid ratio for 43.8 min. The crude extract was then purified by HPD-100 macroporous adsorption resin, and the flavonoids content in the purified extract increased to 54.7%. The antioxidant activity of the purified flavonoids was evaluated in vitro by scavenging capacity of ABTS or DPPH, β-carotene bleaching, and FTC test. The knowledge obtained from this study should be useful to further develop and apply this plant resource.

  13. Response surface methodology for the optimization of sludge solubilization by ultrasonic pre-treatment

    Science.gov (United States)

    Zheng, Mingyue; Zhang, Xiaohui; Lu, Peng; Cao, Qiguang; Yuan, Yuan; Yue, Mingxing; Fu, Yiwei; Wu, Libin

    2018-02-01

    The present study examines the optimization of the ultrasonic pre-treatment conditions with response surface experimental design in terms of sludge disintegration efficiency (solubilisation of organic components). Ultrasonic pre-treatment for the maximum solubilization with residual sludge enhanced the SCOD release. Optimization of the ultrasonic pre-treatment was conducted through a Box-Behnken design (three variables, a total of 17 experiments) to determine the effects of three independent variables (power, residence time and TS) on COD solubilization of sludge. The optimal COD was obtained at 17349.4mg/L, when the power was 534.67W, the time was 10.77, and TS was 2%, while the SE of this condition was 28792J/kg TS.

  14. Surface wipe sampling for antineoplastic (chemotherapy) and other hazardous drug residue in healthcare settings: Methodology and recommendations.

    Science.gov (United States)

    Connor, Thomas H; Zock, Matthew D; Snow, Amy H

    2016-09-01

    Surface wipe sampling for various hazardous agents has been employed in many occupational settings over the years for various reasons such as evaluation of potential dermal exposure and health risk, source determination, quality or cleanliness, compliance, and others. Wipe sampling for surface residue of antineoplastic and other hazardous drugs in healthcare settings is currently the method of choice to determine surface contamination of the workplace with these drugs. The purpose of this article is to review published studies of wipe sampling for antineoplastic and other hazardous drugs, to summarize the methods in use by various organizations and researchers, and to provide some basic guidance for conducting surface wipe sampling for these drugs in healthcare settings.  Recommendations on wipe sampling methodology from several government agencies and organizations were reviewed. Published reports on wipe sampling for hazardous drugs in numerous studies were also examined. The critical elements of a wipe sampling program and related limitations were reviewed and summarized.  Recommendations and guidance are presented concerning the purposes of wipe sampling for antineoplastic and other hazardous drugs in the healthcare setting, technical factors and variables, sampling strategy, materials required, and limitations. The reporting and interpretation of wipe sample results is also discussed.  It is recommended that all healthcare settings where antineoplastic and other hazardous drugs are handled consider wipe sampling as part of a comprehensive hazardous drug "safe handling" program. Although no standards exist for acceptable or allowable surface concentrations for these drugs in the healthcare setting, wipe sampling may be used as a method to characterize potential occupational dermal exposure risk and to evaluate the effectiveness of implemented controls and the overall safety program. A comprehensive safe-handling program for antineoplastic drugs may

  15. Ultrasound-assisted xanthation of cellulose from lignocellulosic biomass optimized by response surface methodology for Pb(II) sorption.

    Science.gov (United States)

    Wang, Chongqing; Wang, Hui; Gu, Guohua

    2018-02-15

    Alkali treatment of lignocellulosic biomass is conducted to remove hemi-cellulose and lignin, further increasing the reactivity and accessibility of cellulose. Ultrasound-assisted xanthation of alkali cellulose is optimized by response surface methodology (RSM) with a Box-Behnken design. A predicting mathematical model is obtained by fitting experimental data, and it is verified by analysis of variance. Response surface plots and the contour plots obtained from the model are applied to determine the interactions of experimental variables. The optimum conditions are NaOH concentration 1.3mol/L, ultrasonic time 71.6min and CS 2 dosage 1.5mL. FTIR, SEM and XPS characterizations confirm the synthesis and sorption mechanism of cellulose xanthate (CX). Biosorption of Pb (II) onto CX obeys pseudo-second order model and Langmuir model. The sorption mechanism is attributed to surface complexation or ion exchange. CX shows good reusability for Pb (II) sorption. The maximum sorption capacity of Pb(II) is 134.41mg/g, higher than that of other biosorbents. CX has great potential as an efficient and low-cost biosorbent for wastewater treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Response surface methodology analysis of the photocatalytic removal of Methylene Blue using bismuth vanadate prepared via polyol route.

    Science.gov (United States)

    Abdullah, Abdul Halim; Moey, Hui Jia Melanie; Yusof, Nor Azah

    2012-01-01

    Visible-light driven photocatalyst bismuth vanadate (BiVO4) photocatalyst was synthesized by the polyol route using ethylene glycol. The precipitate was washed, dried and calcined at 450 degrees C for 3 hr. The sample was characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FE-SEM), zeta potential, surface area (BET method) and band gap energy via diffuse reflectance spectroscopy (DRS). The synthesized BiVO4 has a monoclinic phase with a surface area of 4.3 m2/g and a band gap energy of 2.46 eV. A majority of the particles were in the range of 90-130 nm as obtained from the particle size distribution histrogram. The efficiency of the sample as a visible-light driven photocatalyst was examined by photodegrading Methylene Blue (MB). The effects of some operational photodegradation parameters such as mass loading, initial dye concentration and pH were also examined. Experimental design methodology was applied by response surface modeling and optimization of the removal of MB. The multivariate experimental design was employed to develop a quadratic model as a functional relationship between the percentage removal of MB and three experimental factors (BiVO4 loading, MB initial concentration and pH). The percentage removal of MB approached 67.21% under optimized conditions. In addition, a satisfactory goodness-of-fit was achieved between the,predictive and the experimental results.

  17. Sound in ecclesiastical spaces in Cordoba. Architectural projects incorporating acoustic methodology (El sonido del espacio eclesial en Cordoba. El proyecto arquitectonico como procedimiento acustico)

    Science.gov (United States)

    Suarez, Rafael

    2003-11-01

    This thesis is concerned with the acoustic analysis of ecclesiastical spaces, and the subsequent implementation of acoustic design methodology in architectural renovations. One begins with an adequate architectural design of specific elements (shape, materials, and textures), with the intention of elimination of acoustic deficiencies that are common in such spaces. These are those deficiencies that impair good speech intelligibility and good musical audibility. The investigation is limited to churches in the province of Cordoba and to churches built after the reconquest of Spain (1236) and up until the 18th century. Selected churches are those that have undergone architectural renovations to adapt them to new uses or to make them more suitable for liturgical use. The thesis attempts to summarize the acoustic analyses and the acoustical solutions that have been implemented. The results are presented in a manner that should be useful for the adoption of a model for the functional renovation of ecclesiastical spaces. Such would allow those involved in architectural projects to specify the nature of the sound, even though somewhat intangible, within the ecclesiastical space. Thesis advisors: Jaime Navarro and Juan J. Sendra Copies of this thesis written in Spanish may be obtained by contacting the advisor, Jaime Navarro, E.T.S. de Arquitectura de Sevilla, Dpto. de Construcciones Arquitectonicas I, Av. Reina Mercedes, 2, 41012 Sevilla, Spain. E-mail address: jnavarro@us.es

  18. OPTIMIZATION OF SESAME SEEDS OIL EXTRACTION OPERATING CONDITIONS USING THE RESPONSE SURFACE DESIGN METHODOLOGY

    Directory of Open Access Journals (Sweden)

    HAITHAM OSMAN

    2016-12-01

    Full Text Available This paper applies Response Surface Design (RSD to model the experimental data obtained from the extraction of sesame seeds oil using n-hexane, chloroform and acetone as solvents under different operating conditions. The results obtained revealed that n-hexane outperformed the extraction obtained using chloroform and acetone. The developed model predicted that n-hexane with a rotational speed of 547 rpm and a contact time between the solvent and seeds of 19.46 hours with solvent: seeds ratio of 4.93, yields the optimum oil extracted of 37.03 %, outperforming chloroform and acetone models that gave prediction for 4.75 and 4.21 respectively. While the maximum predictions yield for chloroform is 6.73 %, under the operating conditions of 602 rpm, and 24 hours contact time, with a ratio of solvent: seeds of 1.74. On the other hand the acetone maximum prediction is only 4.37 %, with operational conditions of 467 rpm, and 6.00 hours contact time, with a ratio of solvent: seeds of 1. It is has been found that the maximum oil extraction yield obtained from the chloroform (6.73 % and Acetone (4.37 % is much lower than that predicted by n-hexane 37.03 %.

  19. A Response Surface Methodology for Bi-Level Integrated System Synthesis (BLISS)

    Science.gov (United States)

    Altus, Troy David; Sobieski, Jaroslaw (Technical Monitor)

    2002-01-01

    The report describes a new method for optimization of engineering systems such as aerospace vehicles whose design must harmonize a number of subsystems and various physical phenomena, each represented by a separate computer code, e.g., aerodynamics, structures, propulsion, performance, etc. To represent the system internal couplings, the codes receive output from other codes as part of their inputs. The system analysis and optimization task is decomposed into subtasks that can be executed concurrently, each subtask conducted using local state and design variables and holding constant a set of the system-level design variables. The subtasks results are stored in form of the Response Surfaces (RS) fitted in the space of the system-level variables to be used as the subtask surrogates in a system-level optimization whose purpose is to optimize the system objective(s) and to reconcile the system internal couplings. By virtue of decomposition and execution concurrency, the method enables a broad workfront in organization of an engineering project involving a number of specialty groups that might be geographically dispersed, and it exploits the contemporary computing technology of massively concurrent and distributed processing. The report includes a demonstration test case of supersonic business jet design.

  20. Process optimization by response surface methodology for extracellular alkaline protease production from bacillus subtilis

    International Nuclear Information System (INIS)

    Mushtaq, Z.; Adnan, A.; Mehmood, Z.

    2014-01-01

    Three microbial cultures Bacillus subtilis DSM 1970, Bacillus subtilis GCU-8 and Bacillus licheniformis DSM 1969 were screened for protease production by casein agar plate method. Among these Bacillus subtilis GCU-8 was found to be the most potent protease producer in wide pH range (5.0 to 8.0). Fermentation conditions were optimized for the production of alkaline protease using two statistical tools: Placket Burmen Model for linear regression study and Response Surface Model for interactive effects of significant factors on production. The alkaline protease was optimally produced after 48 hours of incubation at 37 degree C in fermentation media containing equal amounts of substrates (soybean meal and wheat bran, 7.5 g), MgSO/sub 4/ 7H/sub 2/O, 0.10 g and yeast extract 0.55 g. The protease was purified to homogeneity by salt precipitation, ion-exchange chromatography and size exclusion chromatography. The homogeneity and molecular weights were checked by SDS-PAGE. The protease was 45 KDa protein, predominantly alkaline and optimally active at pH 8.0. (author)

  1. Physiochemical Changes and Optimization of Phosphate-Treated Shrimp (Litopenaeus vannamei ) Using Response Surface Methodology.

    Science.gov (United States)

    Omar, Saiah Djebbour; Yang, Je-Eun; Oh, Sang-Cheol; Kim, Dae-Wook; Lee, Yang-Bong

    2016-03-01

    The objective of this study was to determine the factors responsible for the changed physiochemical properties of unpeeled shrimp treated in cold phosphate solution (2~4°C) with the intervention of 4 factors: phosphate concentration, dipping time, rotation speed, and volume of brine solution. Response surface analysis was used to characterize the effect of the phosphate treatment on shrimps by running 33 treatments for optimizing the experiment. For each treatment, phosphate amount, moisture content, and weight gain were measured. The results showed that phosphate concentration is the most important factor than other factors for facilitating phosphate penetration in the meat of the shrimp and for getting the best result. The optimum condition of phosphate-treated shrimp in this study was 110 to 120 min dipping time, 500 to 550 mL brine solution for 100 g shrimp sample, and 190 to 210 rpm agitation speed. The studied conditions can be applied in fisheries and other food industries for good phosphate treatments.

  2. The Use of Response Surface Methodology to Optimize Parameter Adjustments in CNC Machine Tools

    Directory of Open Access Journals (Sweden)

    Shao-Hsien Chen

    2014-01-01

    Full Text Available This paper mainly covers a research intended to improve the circular accuracy of CNC machine tools and the adjustment and analysis of the main controller parameters applied to improve accuracy. In this study, controller analysis software was used to detect the adjustment status of the servo parameters of the feed axis. According to the FANUC parameter manual, the parameter address, frequency, response measurements, and the one-fourth corner acceleration and deceleration measurements of the machine tools were adjusted. The experimental design (DOE was adopted in this study for taking circular measurements and engaging in the planning and selection of important parameter data. The Minitab R15 software was adopted to predict the experimental data analysis, while the seminormal probability map, Plato, and analysis of variance (ANOVA were adopted to determine the impacts of the significant parameter factors and the interactions among them. Additionally, based on the response surface map and contour plot, the optimal values were obtained. In addition, comparison and verification were conducted through the Taguchi method, regression analysis to improved machining accuracy and efficiency. The unadjusted error was 7.8 μm; through the regression analysis method, the error was 5.8 μm and through the Taguchi analysis method, the error was 6.4 μm.

  3. Optimization of Gentisides Extraction from Gentiana rigescens Franch. ex Hemsl. by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Bowen Chu

    2015-01-01

    Full Text Available Gentisides are a class of chemical compounds which is considered as potential therapeutic substance for treatment of neurodegenerative disorders. The heat reflux extraction conditions were optimized for seven kinds of gentisides from the root and rhizome of Gentiana rigescens Franch. ex Hemsl. by employing response surface method. Based on univariate test, a Box-Behnken design (BBD was applied to the survey of relationships between response value (gentisides yield and independent variables which were chosen from various extraction processes, including extraction temperature, extraction time, and solvent-material ratio. The optimized conditions for this extraction are as follows: extraction time of 3.40 h, extraction temperature of 74.33°C, and ratio of solvent to raw material of 10.21 : 1 mL/g. Verification assay revealed that the predicted value (99.24% of extraction parameters from this model was mainly conformed to the experimentally observed values (98.61±0.61.

  4. Decolorization of Ionic Dyes from Synthesized Textile Wastewater by Nanofiltration Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Mehrdad Farhadian

    2015-07-01

    Full Text Available Decolorization of aqueous solutions containing ionic dyes (Reactive Blue 19 and Acid Black 172 by a TFC commercial polyamide nanofilter (NF in a spiral wound configuration was studied. The effect of operating parameters including feed concentration (60-180 mg/l, pressure (0.5-1.1 MPa and pH (6-10 on dye removal efficiency was evaluated. The response surface method (RSM was utilized for the experimental design and statistical analysis to identify the impact of each factor. The results showed that an increase in the dye concentration and pH can significantly enhance the removal efficiency from 88% and 87% up to 95% and 93% for Reactive and Acid dye, respectively. The effect of pressure on the removal efficiency showed different behavior such that by the raise of pressure from 0.5 to 0.8 MPa, the removal efficiency increased to its maximum, then reduction in removal efficiency was observed by further increases in pressure above the optimum range. The maximum dye removal efficiencies which were predicted at the optimum conditions by Design Expert software were 97 % and 94 % for Reactive Blue 19 and Acid Black 172, respectively. According to the results of this study, NF processes can be used at a significantly lower pressure and fouling issue for reuse applications as an alternative to the widely used RO process.

  5. Optimization of tetanus toxoid ammonium sulfate precipitation process using response surface methodology.

    Science.gov (United States)

    Brgles, Marija; Prebeg, Pero; Kurtović, Tihana; Ranić, Jelena; Marchetti-Deschmann, Martina; Allmaier, Günter; Halassy, Beata

    2016-10-02

    Tetanus toxoid (TTd) is a highly immunogenic, detoxified form of tetanus toxin, a causative agent of tetanus disease, produced by Clostridium tetani. Since tetanus disease cannot be eradicated but is easily prevented by vaccination, the need for the tetanus vaccine is permanent. The aim of this work was to investigate the possibility of optimizing TTd purification, i.e., ammonium sulfate precipitation process. The influence of the percentage of ammonium sulfate, starting amount of TTd, buffer type, pH, temperature, and starting purity of TTd on the purification process were investigated using optimal design for response surface models. Responses measured for evaluation of the ammonium sulfate precipitation process were TTd amount (Lf/mL) and total protein content. These two parameters were used to calculate purity (Lf/mgPN) and the yield of the process. Results indicate that citrate buffer, lower temperature, and lower starting amount of TTd result in higher purities of precipitates. Gel electrophoresis combined with matrix-assisted laser desorption ionization-mass spectrometric analysis of precipitates revealed that there are no inter-protein cross-links and that all contaminating proteins have pIs similar to TTd, so this is most probably the reason for the limited success of purification by precipitation.

  6. Investigation of waste biomass co-pyrolysis with petroleum sludge using a response surface methodology.

    Science.gov (United States)

    Hu, Guangji; Li, Jianbing; Zhang, Xinying; Li, Yubao

    2017-05-01

    The treatment of waste biomass (sawdust) through co-pyrolysis with refinery oily sludge was carried out in a fixed-bed reactor. Response surface method was applied to evaluate the main and interaction effects of three experimental factors (sawdust percentage in feedstock, temperature, and heating rate) on pyrolysis oil and char yields. It was found that the oil and char yields increased with sawdust percentage in feedstock. The interaction between heating rate and sawdust percentage as well as between heating rate and temperature was significant on the pyrolysis oil yield. The higher heating value of oil originated from sawdust during co-pyrolysis at a sawdust/oily sludge ratio of 3:1 increased by 5 MJ/kg as compared to that during sawdust pyrolysis alone, indicating a synergistic effect of co-pyrolysis. As a result, petroleum sludge can be used as an effective additive in the pyrolysis of waste biomass for improving its energy recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Sustained release biodegradable solid lipid microparticles: Formulation, evaluation and statistical optimization by response surface methodology

    Directory of Open Access Journals (Sweden)

    Hanif Muhammad

    2017-12-01

    Full Text Available For preparing nebivolol loaded solid lipid microparticles (SLMs by the solvent evaporation microencapsulation process from carnauba wax and glyceryl monostearate, central composite design was used to study the impact of independent variables on yield (Y1, entrapment efficiency (Y2 and drug release (Y3. SLMs having a 10-40 μm size range, with good rheological behavior and spherical smooth surfaces, were produced. Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffractometry pointed to compatibility between formulation components and the zeta-potential study confirmed better stability due to the presence of negative charge (-20 to -40 mV. The obtained outcomes for Y1 (29-86 %, Y2 (45-83 % and Y3 (49-86 % were analyzed by polynomial equations and the suggested quadratic model were validated. Nebivolol release from SLMs at pH 1.2 and 6.8 was significantly (p 0.85 value (Korsmeyer- Peppas suggested slow erosion along with diffusion. The optimized SLMs have the potential to improve nebivolol oral bioavailability.

  8. Robust Imaging Methodology for Challenging Environments: Wave Equation Dispersion Inversion of Surface Waves

    KAUST Repository

    Li, Jing

    2017-12-22

    A robust imaging technology is reviewed that provide subsurface information in challenging environments: wave-equation dispersion inversion (WD) of surface waves for the shear velocity model. We demonstrate the benefits and liabilities of the method with synthetic seismograms and field data. The benefits of WD are that 1) there is no layered medium assumption, as there is in conventional inversion of dispersion curves, so that the 2D or 3D S-velocity model can be reliably obtained with seismic surveys over rugged topography, and 2) WD mostly avoids getting stuck in local minima. The synthetic and field data examples demonstrate that WD can accurately reconstruct the S-wave velocity distributions in laterally heterogeneous media if the dispersion curves can be identified and picked. The WD method is easily extended to anisotropic media and the inversion of dispersion curves associated with Love wave. The liability is that is almost as expensive as FWI and only recovers the Vs distribution to a depth no deeper than about 1/2~1/3 wavelength.

  9. Immobilization of β-Galactosidase onto Functionalized Graphene Nano-sheets Using Response Surface Methodology and Its Analytical Applications

    Science.gov (United States)

    Kishore, Devesh; Talat, Mahe; Srivastava, Onkar Nath; Kayastha, Arvind M.

    2012-01-01

    Background β-Galactosidase is a vital enzyme with diverse application in molecular biology and industries. It was covalently attached onto functionalized graphene nano-sheets for various analytical applications based on lactose reduction. Methodology/Principal Findings Response surface methodology based on Box-Behnken design of experiment was used for determination of optimal immobilization conditions, which resulted in 84.2% immobilization efficiency. Native and immobilized functionalized graphene was characterized with the help of transmission and scanning electron microscopy, followed by Fourier transform infrared (FTIR) spectroscopy. Functionalized graphene sheets decorated with islands of immobilized enzyme were evidently visualized under both transmission and scanning electron microscopy after immobilization. FTIR spectra provided insight on various chemical interactions and bonding, involved during and after immobilization. Optimum temperature and energy of activation (Ea) remains unchanged whereas optimum pH and Km were changed after immobilization. Increased thermal stability of enzyme was observed after conjugating the enzyme with functionalized graphene. Significance Immobilized β-galactosidase showed excellent reusability with a retention of more than 92% enzymatic activity after 10 reuses and an ideal performance at broad ranges of industrial environment. PMID:22815797

  10. Application of the methodology of surface of answer in the determination of the PCT in the simulation of a LOFT

    International Nuclear Information System (INIS)

    Alva N, J.; Ortiz V, J.; Amador G, R.

    2008-01-01

    This article summarizes the main typical of the methodology of surfaces and answer (MSA) and its connections with the lineal regression analysis. Also, an example of the application of MSA in the prediction of the principle cladding temperature (PCT) of a combustible assembly of a nuclear reactor, whose used data were taken from the simulation of a LOFT (Loss Of Fluid Test) during a course of experts. The made prediction will be used like one first approach to predict the behavior of the PCT, this is made in order to diminish the time of calculation when realizing the executions of codes thermal hydraulics of better estimation. The present work comprises of the theoretical base of the project in charge to delineate a methodology of uncertainty analysis for codes of better estimation, employees in the thermal hydraulics analysis and safety of plants and nuclear reactors. The institutions that participate in such project are: ININ, CFE, IPN and CNSNS, is possible to mention that this project is sponsored by the IAEA. (Author)

  11. Process Optimization of Eco-Friendly Flame Retardant Finish for Cotton Fabric: a Response Surface Methodology Approach

    Science.gov (United States)

    Yasin, Sohail; Curti, Massimo; Behary, Nemeshwaree; Perwuelz, Anne; Giraud, Stephane; Rovero, Giorgio; Guan, Jinping; Chen, Guoqiang

    The n-methylol dimethyl phosphono propionamide (MDPA) flame retardant compounds are predominantly used for cotton fabric treatments with trimethylol melamine (TMM) to obtain better crosslinking and enhanced flame retardant properties. Nevertheless, such treatments are associated with a toxic issue of cancer-causing formaldehyde release. An eco-friendly finishing was used to get formaldehyde-free fixation of flame retardant to the cotton fabric. Citric acid as a crosslinking agent along with the sodium hypophosphite as a catalyst in the treatment was utilized. The process parameters of the treatment were enhanced for optimized flame retardant properties, in addition, low mechanical loss to the fabric by response surface methodology using Box-Behnken statistical design experiment methodology was achieved. The effects of concentrations on the fabric’s properties (flame retardancy and mechanical properties) were evaluated. The regression equations for the prediction of concentrations and mechanical properties of the fabric were also obtained for the eco-friendly treatment. The R-squared values of all the responses were above 0.95 for the reagents used, indicating the degree of relationship between the predicted values by the Box-Behnken design and the actual experimental results. It was also found that the concentration parameters (crosslinking reagents and catalysts) in the treatment formulation have a prime role in the overall performance of flame retardant cotton fabrics.

  12. Material Removal Rate, Electrode Wear Rate, and Surface Roughness Evaluation in Die Sinking EDM with Hollow Tool through Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Teepu Sultan

    2014-01-01

    Full Text Available Electrical discharge machining is one of the earliest nontraditional machining, extensively used in industry for processing of parts having unusual profiles with reasonable precision. In the present work, an attempt has been made to model material removal rate, electrode wear rate, and surface roughness through response surface methodology in a die sinking EDM process. The optimization was performed in two steps using one factor at a time for preliminary evaluation and a Box-Behnken design involving three variables with three levels for determination of the critical experimental conditions. Pulse on time, pulse off time, and peak current were changed during the tests, while a copper electrode having tubular cross section was employed to machine through holes on EN 353 steel alloy workpiece. The results of analysis of variance indicated that the proposed mathematical models obtained can adequately describe the performances within the limits of factors being studied. The experimental and predicted values were in a good agreement. Surface topography is revealed with the help of scanning electron microscope micrographs.

  13. Optimization of the Extraction of Antioxidants and Caffeine from Maté (Ilex paraguariensis Leaves by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Vanessa Graciela Hartwig

    2013-04-01

    Full Text Available Optimal conditions for the industrial extraction of total polyphenols from maté (Ilex paraguariensis were determined using response surface methodology, with two independent variables: ethanol percentage of the extraction solution and liquid to solid ratio. Response variables were total polyphenol content, antioxidant capacity, concentration of total polyphenols and caffeine content. The optimal conditions found were a liquid to solid ratio from 8 - 9 w w-1 and ethanol percentage of the extraction solution from 30 -50 % w w-1. Under these conditions the main predicted values corresponding to leaf extracts were 40 μg chlorogenic acid equivalents mL-1 of original extract, 13 g chlorogenic acid equivalents per 100 g dry matter for total polyphenol content, 22 g Trolox equivalents and 15.5 g ascorbic acid equivalents per 100 g dry matter for antioxidant capacity. The total polyphenol content of twig extracts was 36% lower than that in the leaf extracts.

  14. Optimization of extraction of linarin from Flos chrysanthemi indici by response surface methodology and artificial neural network.

    Science.gov (United States)

    Pan, Hongye; Zhang, Qing; Cui, Keke; Chen, Guoquan; Liu, Xuesong; Wang, Longhu

    2017-05-01

    The extraction of linarin from Flos chrysanthemi indici by ethanol was investigated. Two modeling techniques, response surface methodology and artificial neural network, were adopted to optimize the process parameters, such as, ethanol concentration, extraction period, extraction frequency, and solvent to material ratio. We showed that both methods provided good predictions, but artificial neural network provided a better and more accurate result. The optimum process parameters include, ethanol concentration of 74%, extraction period of 2 h, extraction three times, solvent to material ratio of 12 mL/g. The experiment yield of linarin was 90.5% that deviated less than 1.6% from that obtained by predicted result. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Determination of optimum pH and temperature for pasteurization of citrus juices by response surface methodology.

    Science.gov (United States)

    Ulgen, N; Ozilgen, M

    1993-01-01

    Optimization of microbial death, enzyme inactivation and vitamin C retention during pasteurization of pH-adjusted orange juice is discussed free of equipment-dependent parameters such as the heating lag. The pH-temperature optimum was determined by response surface methodology in the range of 65 degrees C-75 degrees C and pH 2.5-4.0. The results implied that there was no pectinesterase activity below pH 3.5. Leuconostoc mesenteroides had its maximum and minimum thermal resistance at pH 3.5 and pH 2.7, respectively. For an ideal theoretical process requiring four log cycles of microbial reduction the optimum pasteurization conditions were 12 min at 75 degrees C and pH 2.7.

  16. Response surface methodology applied to the generation of casein hydrolysates with antioxidant and dipeptidyl peptidase IV inhibitory properties.

    Science.gov (United States)

    Nongonierma, Alice B; Maux, Solène Le; Esteveny, Claire; FitzGerald, Richard J

    2017-03-01

    Hydrolysis parameters affecting the release of dipeptidyl peptidase IV (DPP-IV) inhibitory and antioxidant peptides from milk proteins have not been extensively studied. Therefore, a multifactorial (i.e. pH, temperature and hydrolysis time) composite design was used to optimise the release of bioactive peptides (BAPs) with DPP-IV inhibitory and antioxidant [oxygen radical absorbance capacity (ORAC)] properties from sodium caseinate. Fifteen sodium caseinate hydrolysates (H1-H15) were generated with Protamex TM , a bacillus proteinase activity. Hydrolysis time (1 to 5 h) had the highest influence on both DPP-IV inhibitory properties and ORAC activity (P 0.05) as the response surface methodology (RSM) predicted optimum bioactivities. Generation of milk protein hydrolysates through multifactorial design approaches may aid in the optimal enzymatic release of BAPs with serum glucose lowering and antioxidant properties. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  17. Optimization of chromium and tannic acid bioremediation by Aspergillus niveus using Plackett-Burman design and response surface methodology.

    Science.gov (United States)

    Chaudhary, Prachi; Chhokar, Vinod; Choudhary, Pragati; Kumar, Anil; Beniwal, Vikas

    2017-11-14

    A chromium and tannic acid resistance fungal strain was isolated from tannery effluent, and identified as Aspergillus niveus MCC 1318 based on its rDNA gene sequence. The MIC (minimum inhibitory concentration) of the isolate against chromium and tannic acid was found to be 200 ppm and 5% respectively. Optimization of physiochemical parameters for biosorption of chromium and tannic acid degradation was carried out by Plackett-Burman design followed by response surface methodology (RSM). The maximum chromium removal and tannic acid degradation was found to be 92 and 68% respectively by A. niveus. Chromium removal and tannic acid degradation was increased up to 11 and 6% respectively after optimization. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) was used to investigate biosorption phenomena.

  18. Optimization of ultrasound-assisted extraction of flavonoids compounds from Chenopodium hybridum L. stem with response surface methodology

    Science.gov (United States)

    Wu, Y.; Hu, H. B.; Wang, C. L.; Ma, S. R.; Zhang, L. L.

    2016-08-01

    Ultrasound-assisted extraction (UAE) of flavonoids compounds (FC) from the stem of Chenopodium hybridum L.(C.hybridum L.) was investigated in this paper. Significant technological parameters were screened and optimized by using Plackett-Burman (PB) design, Steepest ascent method and Box-Behnken (BB) design, respectively. A mathematical model with high correlation coefficient (R2=0.9896) was developed and showed good consistency between the experimental and predicted values. The optimum conditions for UAE were obtained by res- ponse surface methodology (RSM) as follows: volumn fraction of ethanol 76.62 %, extractive temperature 78.69°C, and liquid to solid ratio 58.43 for 30 min. Under these conditions, total flavo- noid content (TFC) of 9.4701 mg RE/100g were gained and it was closely related with predi- cted value (9.4640 mg RE/100g) and indicated the suitability of the developed model.

  19. Application of Plackett-Burman design and response surface methodology to achieve exponential growth for aggregated shipworm bacterium.

    Science.gov (United States)

    Ahuja, S K; Ferreira, G M; Moreira, A R

    2004-03-20

    Here we report the successful implementation of the Plackett-Burman multifactorial design to screen the limiting components for growth and subsequent use of the response surface methodology (RSM) to design a medium that supported exponential growth of the aggregated morphology of the shipworm bacterium, Teredinobacter turnirae. The results obtained with the help of Plackett-Burman design indicated limitations of three components in the growth medium, MnCl2.4H2O, Na2CO3, and K2HPO4. The concentrations of these three components were further optimized using RSM. By increasing the concentrations of the above-mentioned components by 4-fold, 12-fold, and 12-fold, respectively, it became possible to achieve exponential growth of the culture. Copyright 2004 Wiley Periodicals, Inc.

  20. Optimisation of Ultrasound-Assisted Extraction Conditions for Phenolic Content and Antioxidant Capacity from Euphorbia tirucalli Using Response Surface Methodology

    Science.gov (United States)

    Vuong, Quan V.; Goldsmith, Chloe D.; Dang, Trung Thanh; Nguyen, Van Tang; Bhuyan, Deep Jyoti; Sadeqzadeh, Elham; Scarlett, Christopher J.; Bowyer, Michael C.

    2014-01-01

    Euphorbia tirucalli (E. tirucalli) is now widely distributed around the world and is well known as a source of traditional medicine in many countries. This study aimed to utilise response surface methodology (RSM) to optimise ultrasonic-assisted extraction (UAE) conditions for total phenolic compounds (TPC) and antioxidant capacity from E. tirucalli leaf. The results showed that ultrasonic temperature, time and power effected TPC and antioxidant capacity; however, the effects varied. Ultrasonic power had the strongest influence on TPC; whereas ultrasonic temperature had the greatest impact on antioxidant capacity. Ultrasonic time had the least impact on both TPC and antioxidant capacity. The optimum UAE conditions were determined to be 50 °C, 90 min. and 200 W. Under these conditions, the E. tirucalli leaf extract yielded 2.93 mg GAE/g FW of TPC and exhibited potent antioxidant capacity. These conditions can be utilised for further isolation and purification of phenolic compounds from E. tirucalli leaf. PMID:26785074

  1. Optimization of bread quality from 650 wheat flour type with native inulin by response surface methodology

    Directory of Open Access Journals (Sweden)

    Camelia ARGHIRE

    2016-08-01

    Full Text Available The aim of this study was to evaluate the effect of native inulin addition on the wheat flour bread quality. Since it is known the fact that inulin addition decreases wheat flour dough water absorption, we wanted to obtain an optimum formulation of wheat flour bread by response surface methodology considering independent process variables in fixed proportion of inulin fiber in wheat flour as 0, 2.5, 5 and 10% and water addition as 45, 50, 55 and 60 %. With respect to bread quality characteristics, loaf volume, porosity and elasticity were evaluated. The results showed that the optimum bread formulation was obtained for native inulin addition of 3.52% and water absorption of 55.62% for which predicted bread quality characteristics are 373.08cm3/100g loaf volume, 85.07% porosity and 92.57% elasticity.

  2. Spectroscopic, energetic and metallographic investigations of the laser lap welding of AISI 304 using the response surface methodology

    Science.gov (United States)

    Rizzi, Domenico; Sibillano, Teresa; Pietro Calabrese, Paolo; Ancona, Antonio; Mario Lugarà, Pietro

    2011-07-01

    Spectroscopic signals originated by the laser-induced plasma optical emission have been simultaneously investigated together with energetic and metallographic analyses of CO 2 laser welded stainless steel lap joint, using the Response Surface Methodology. This statistical approach allowed us to study the influence of the laser beam power and the laser welding speed on the following response parameters: plasma plume electron temperature, joint penetration depth and melted area. A clear correlation has been found between all the investigated response parameters. The results have been shown to be consistent with quantitative considerations on the energy supplied to the workpiece as far as the laser power and travel speed were varied. The regression model obtained in this way could be a valuable starting point to develop a closed loop control of the weld penetration depth and the melted area in the investigated process window.

  3. Optimization of ultrasonic-assisted extraction of antioxidant compounds from Guava (Psidium guajava L.) leaves using response surface methodology.

    Science.gov (United States)

    Kong, Fansheng; Yu, Shujuan; Feng, Zeng; Wu, Xinlan

    2015-01-01

    To optimization of extraction of antioxidant compounds from guava (Psidium guajava L.) leaves and showed that the guava leaves are the potential source of antioxidant compounds. The bioactive polysaccharide compounds of guava leaves (P. guajava L.) were obtained using ultrasonic-assisted extraction. Extraction was carried out according to Box-Behnken central composite design, and independent variables were temperature (20-60°C), time (20-40 min) and power (200-350 W). The extraction process was optimized by using response surface methodology for the highest crude extraction yield of bioactive polysaccharide compounds. The optimal conditions were identified as 55°C, 30 min, and 240 W. 1,1-diphenyl-2-picryl-hydrazyl and hydroxyl free radical scavenging were conducted. The results of quantification showed that the guava leaves are the potential source of antioxidant compounds.

  4. Optimisation on processing parameters for minimising warpage on side arm using response surface methodology (RSM) and particle swarm optimisation (PSO)

    Science.gov (United States)

    Rayhana, N.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.; Sazli, M.; Yahya, Z. R.

    2017-09-01

    This study presents the application of optimisation method to reduce the warpage of side arm part. Autodesk Moldflow Insight software was integrated into this study to analyse the warpage. The design of Experiment (DOE) for Response Surface Methodology (RSM) was constructed and by using the equation from RSM, Particle Swarm Optimisation (PSO) was applied. The optimisation method will result in optimised processing parameters with minimum warpage. Mould temperature, melt temperature, packing pressure, packing time and cooling time was selected as the variable parameters. Parameters selection was based on most significant factor affecting warpage stated by previous researchers. The results show that warpage was improved by 28.16% for RSM and 28.17% for PSO. The warpage improvement in PSO from RSM is only by 0.01 %. Thus, the optimisation using RSM is already efficient to give the best combination parameters and optimum warpage value for side arm part. The most significant parameters affecting warpage are packing pressure.

  5. An Effective Vacuum Assisted Extraction Method for the Optimization of Labdane Diterpenoids from Andrographis paniculata by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Ya-Qi Wang

    2014-12-01

    Full Text Available An effective vacuum assisted extraction (VAE technique was proposed for the first time and applied to extract bioactive components from Andrographis paniculata. The process was carefully optimized by response surface methodology (RSM. Under the optimized experimental conditions, the best results were obtained using a boiling temperature of 65 °C, 50% ethanol concentration, 16 min of extraction time, one extraction cycles and a 12:1 liquid-solid ratio. Compared with conventional ultrasonic assisted extraction and heat reflux extraction, the VAE technique gave shorter extraction times and remarkable higher extraction efficiency, which indicated that a certain degree of vacuum gave the solvent a better penetration of the solvent into the pores and between the matrix particles, and enhanced the process of mass transfer. The present results demonstrated that VAE is an efficient, simple and fast method for extracting bioactive components from A. paniculata, which shows great potential for becoming an alternative technique for industrial scale-up applications.

  6. Parametric optimization for floating drum anaerobic bio-digester using Response Surface Methodology and Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    S. Sathish

    2016-12-01

    Full Text Available The main purpose of this study to increase the optimal conditions for biogas yield from anaerobic digestion of agricultural waste (Rice Straw using Response Surface Methodology (RSM and Artificial Neural Network (ANN. In the development of predictive models temperature, pH, substrate concentration and agitation time are conceived as model variables. The experimental results show that the liner model terms of temperature, substrate concentration and pH, agitation time have significance of interactive effects (p < 0.05. The results manifest that the optimum process parameters affected on biogas yield increase from the ANN model when compared to RSM model. The ANN model indicates that it is much more accurate and reckons the values of maximum biogas yield when compared to RSM model.

  7. Development of cookies made with cocoyam, fermented sorghum and germinated pigeon pea flour blends using response surface methodology.

    Science.gov (United States)

    Okpala, Laura C; Okoli, Eric C

    2014-10-01

    Cookies were produced from blends of cocoyam, fermented sorghum and germinated pigeon pea flours. The study was carried out to evaluate the effects of varying the proportions of these components on the sensory and protein quality of the cookies. The sensory attributes studied were colour, taste, texture, crispness and general acceptability while the protein quality indices were biological value (BV) and net protein utilization (NPU). Mixture response surface methodology was used to model the sensory and protein quality with single, binary and ternary combinations of germinated pigeon pea, fermented sorghum and cocoyam flours. Results showed that BV and NPU of most of the cookies were above minimum acceptable levels. With the exception of cookies containing high levels of pigeon pea flour, cookies had acceptable sensory scores. Increase in pigeon pea flour resulted in increase in the BV and NPU. Regression equations suggested that the ternary blends produced the highest increase in all the sensory attributes (with the exception of colour).

  8. Preparation, characterization, and optimization of altretamine-loaded solid lipid nanoparticles using Box-Behnken design and response surface methodology.

    Science.gov (United States)

    Gidwani, Bina; Vyas, Amber

    2016-01-01

    The objective of the present study was to prepare solid lipid nanoparticles (SLNs) of altretamine (ALT) by the hot homogenization and ultrasonication method. The study was conducted using the Box-Behnken design (BBD), with a 3(3) design and a total of 17 experimental runs, performed in combination with response surface methodology (RSM). The SLNs were evaluated for mean particle size, entrapment efficiency, and drug-loading. The optimized formulation, with a desirability factor of 0.92, was selected and characterized. In vitro release studies showed a biphasic release pattern from the SLNs for up to 24 h. The results of % EE (93.21 ± 1.5), %DL (1.15 ± 0.6), and mean diameter of (100.6 ± 2.1) nm, were very close to the predicted values.

  9. Study on decaying characteristics of activated sludge from a circular plug-flow reactor using response surface methodology.

    Science.gov (United States)

    Xie, En; Ding, Aizhong; Dou, Junfeng; Zheng, Lei; Yang, Jin

    2014-10-01

    Using pH values, temperature, and dissolved oxygen as the influencing factors, a decaying characteristics experiment of activated sludge was carried out by combining the LIVE/DEAD® Baclight technique with the 2,3,5-triphenyl tetrazolium chloride - dehydrogenase activity determination method. Using batch experiments, a response surface methodology was applied in the experimental design to determine the most important influential factor in the decay of activated sludge. The activated sludge mixed liquor for the experiment was generated in a laboratory-scale circular plug-flow reactor, which has already been approved for an invention patent. The analyzed results revealed that the most important influential factor in sludge activity decay is the pH, followed by temperature and then dissolved oxygen. After the decay experiment, 40.94-90.03% of sludge activity decay is caused by reduced cell activity, and the rest is due to cell death. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Alpha-amylase production by Streptomyces erumpens MTCC 7317 in solid state fermentation using response surface methodology (RSM).

    Science.gov (United States)

    Kar, Shaktimay; Ray, Ramesh C; Mohapatra, Uma B

    2008-01-01

    Production of alpha-amylase under solid state fermentation by Streptomyces erumpens MTCC 7317 has been investigated using different agro-industrial residues, i.e. cassava bagasse, sugarcane bagasse and wheat bran; wheat bran was found to be the best substrate. Among different nitrogen source supplemented to wheat bran, beef extract or peptone (1%) showed maximum enzyme production. Response surface methodology was used to evaluate the effect of main process parameters as incubation period (48 h), moisture holding capacity (70%), pH (7.0) and temperature (50 degrees C) on enzyme production by applying a full factorial central composite design. The maximum hydrolysis of soluble starch (90%) and cassava starch (75%) was obtained with the application of 4 ml (approximately 12096 U) of S. erumpens crude enzyme after 5 h of incubation.

  11. Reliability Sensitivity Analysis and Design Optimization of Composite Structures Based on Response Surface Methodology

    Science.gov (United States)

    Rais-Rohani, Masoud

    2003-01-01

    This report discusses the development and application of two alternative strategies in the form of global and sequential local response surface (RS) techniques for the solution of reliability-based optimization (RBO) problems. The problem of a thin-walled composite circular cylinder under axial buckling instability is used as a demonstrative example. In this case, the global technique uses a single second-order RS model to estimate the axial buckling load over the entire feasible design space (FDS) whereas the local technique uses multiple first-order RS models with each applied to a small subregion of FDS. Alternative methods for the calculation of unknown coefficients in each RS model are explored prior to the solution of the optimization problem. The example RBO problem is formulated as a function of 23 uncorrelated random variables that include material properties, thickness and orientation angle of each ply, cylinder diameter and length, as well as the applied load. The mean values of the 8 ply thicknesses are treated as independent design variables. While the coefficients of variation of all random variables are held fixed, the standard deviations of ply thicknesses can vary during the optimization process as a result of changes in the design variables. The structural reliability analysis is based on the first-order reliability method with reliability index treated as the design constraint. In addition to the probabilistic sensitivity analysis of reliability index, the results of the RBO problem are presented for different combinations of cylinder length and diameter and laminate ply patterns. The two strategies are found to produce similar results in terms of accuracy with the sequential local RS technique having a considerably better computational efficiency.

  12. Quality Control Methodology Of A Surface Wind Observational Database In North Eastern North America

    Science.gov (United States)

    Lucio-Eceiza, Etor E.; Fidel González-Rouco, J.; Navarro, Jorge; Conte, Jorge; Beltrami, Hugo

    2016-04-01

    This work summarizes the design and application of a Quality Control (QC) procedure for an observational surface wind database located in North Eastern North America. The database consists of 526 sites (486 land stations and 40 buoys) with varying resolutions of hourly, 3 hourly and 6 hourly data, compiled from three different source institutions with uneven measurement units and changing measuring procedures, instrumentation and heights. The records span from 1953 to 2010. The QC process is composed of different phases focused either on problems related with the providing source institutions or measurement errors. The first phases deal with problems often related with data recording and management: (1) compilation stage dealing with the detection of typographical errors, decoding problems, site displacements and unification of institutional practices; (2) detection of erroneous data sequence duplications within a station or among different ones; (3) detection of errors related with physically unrealistic data measurements. The last phases are focused on instrumental errors: (4) problems related with low variability, placing particular emphasis on the detection of unrealistic low wind speed records with the help of regional references; (5) high variability related erroneous records; (6) standardization of wind speed record biases due to changing measurement heights, detection of wind speed biases on week to monthly timescales, and homogenization of wind direction records. As a result, around 1.7% of wind speed records and 0.4% of wind direction records have been deleted, making a combined total of 1.9% of removed records. Additionally, around 15.9% wind speed records and 2.4% of wind direction data have been also corrected.

  13. Downscaling Surface Water Inundation from Coarse Data to Fine-Scale Resolution: Methodology and Accuracy Assessment

    Directory of Open Access Journals (Sweden)

    Guiping Wu

    2015-11-01

    Full Text Available The availability of water surface inundation with high spatial resolution is of fundamental importance in several applications such as hydrology, meteorology and ecology. Medium spatial resolution sensors, like MODerate-resolution Imaging Spectroradiometer (MODIS, exhibit a significant potential to study inundation dynamics over large areas because of their high temporal resolution. However, the low spatial resolution provided by MODIS is not appropriate to accurately delineate inundation over small scale. Successful downscaling of water inundation from coarse to fine resolution would be crucial for improving our understanding of complex inundation characteristics over the regional scale. Therefore, in this study, we propose an innovative downscaling method based on the normalized difference water index (NDWI statistical regression algorithm towards generating small-scale resolution inundation maps from MODIS data. The method was then applied to the Poyang Lake of China. To evaluate the performance of the proposed downscaling method, qualitative and quantitative comparisons were conducted between the inundation extent of MODIS (250 m, Landsat (30 m and downscaled MODIS (30 m. The results indicated that the downscaled MODIS (30 m inundation showed significant improvement over the original MODIS observations when compared with simultaneous Landsat (30 m inundation. The edges of the lakes become smoother than the results from original MODIS image and some undetected water bodies were delineated with clearer shapes in the downscaled MODIS (30 m inundation map. With respect to high-resolution Landsat TM/ETM+ derived inundation, the downscaling procedure has significantly increased the R2 and reduced RMSE and MAE both for the inundation area and for the value of landscape metrics. The main conclusion of this study is that the downscaling algorithm is promising and quite feasible for the inundation mapping over small-scale lakes.

  14. Loteprednol Etabonate Nanoparticles: Optimization via Box-Behnken Design Response Surface Methodology and Physicochemical Characterization.

    Science.gov (United States)

    Sah, Abhishek K; Suresh, Preeti K

    2017-01-01

    Abstract: The objective of the present work was to prepare and optimize the loteprednoletabonate (LE) loaded poly (D,L-lactide co-glycolide) (PLGA) polymer based nanoparticle carrier. The review on recent patents (US9006241, US20130224302A1, US2012/0028947A1) assisted in the selection of drug and polymer for designing nanoparticles for ocular delivery applications. The nanoparticles were prepared by solvent evaporation followed by high speed homogenization. Biodegradable polymer PLGA (50:50) grade was utilized to develop various formulations with different drug:polymer ratio. A Box-Behnken design with 33 factorial design was selected for the present study and 17 runs were carried out in totality. The influence of various process variables (viz., polymer concentration, homogenization speed and sonication time) on the characteristics of nanoparticles including the in vitro drug release profile were studied. The nanoparticulate formulations were evaluated for mean spherical diameter, polydispersity index (PDI), zeta potential, surface morphology, drug entrapment and in-vitro drug release profile. The entrapment efficiency, drug loading and mean particle size were found to be 96.31±1.68 %, 35.46±0.35 % and 167.6±2.1 nm respectively. The investigated process and formulation variables were found to have significant effect on the particle size, drug loading (DL), entrapment efficiency (EE), and in vitro drug release profile. A biphasic in vitro drug release profile was apparent from the optimized nanoparticles (NPs) for 24 hours. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Prediction of the antiglycation activity of polysaccharides from Benincasa hispida using a response surface methodology.

    Science.gov (United States)

    Jiang, Xiang; Kuang, Fei; Kong, Fansheng; Yan, Chunyan

    2016-10-20

    Benincasa hispida is a popular vegetable in China. Our previous experiments suggested that polysaccharides isolated from B. hispida fruits (PBH) have antiglycation effect and DPPH free radical scavenging activity. Ultrasonic treatments can be used to extract polysaccharides from Benincasa hispida (PBH). The aim of this study was to investigate the correlation between the ultrasonic treatment conditions and the antiglycation activity of PBH. A mathematical model was generated with an artificial neural network (ANN) toolbox from MATLAB to analyze the effects of ultrasonic treatment conditions on antiglycation activity. The response surface plots showed relationships between ultrasonic extraction conditions and bioactivity. The R(2) value of the model was 0.9919, which suggested good fitness of the neural network. The application of genetic algorithms showed that the optimal ultrasonic extraction conditions resulted in the highest antiglycation activity for PBH. These were 150W, 46°C, and 35min. These conditions produced a predicted antiglycation activity of 41.2%; the actual activity was 40.9% under optimal conditions. This is very close to the predicted value. The experimental data indicated that the PBH possessed both antiglycation and antioxidant activities. The maximum actual value of antiglycation was 101.7% that of the positive control, and the PBH inhibited the DPPH free radicals with an EC50 value of 0.98mg/mL. This is 66.2% that of ascorbic acid. These results explained the observations that B. hispida can decrease glucose levels in diabetic patients. The experimental results also showed that the ANN could be used for optimization and prediction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Extraction optimization by response surface methodology: Purification and characterization of phytosterol from sugarcane (Saccharum officinarum L.) rind.

    Science.gov (United States)

    Feng, Simin; Luo, Zisheng; Zhong, Zhou; Jiang, Lei; Tang, Kaichen

    2014-06-01

    A green, simple, and effective method for the extraction of sugarcane lipids from sugarcane rind was investigated by response surface methodology. The optimum conditions of technological progress obtained through response surface methodology were as follows: liquid-to-solid ratio 7.94: 1 mL/g, extraction temperature 50°C and extraction time 5.98 h. The practical sugarcane lipids extraction yield was 6.55 ± 0.28%, which was in good consistence with the predicted extraction yield of 6.47%. The results showed that the sugarcane lipids extraction yield obtained in optimum conditions increased by 1.16∼7.28-fold compared to the yields obtained in single-factor experiments. After saponification and SPE steps, the nonsaponifiable fraction of sugarcane lipids was analyzed by gas chromatography with mass spectrometry and high-performance liquid chromatography. β-Sitosterol, stigmasterol, and campesterol were the prevailing phytosterols in the sample, while fucosterol, gramisterol, stigmast-7-en-3-ol, (3β,5α,24S)-, stigmasta-4,6,22-trien-3α-ol, and cholest-8(14)-en-3β-ol acetate were also identified as minor steroids. Furthermore, the content of β-sitosterol and a mixture of campesterol and stigmasterol (quantified by high-performance liquid chromatography) was 44.18 mg/100 g dry weight and 43.20 mg stigmasterol/100 g dry weight, respectively. Our results indicate that sugarcane rind is a good source of phytosterol. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. D-isoascorbyl palmitate: lipase-catalyzed synthesis, structural characterization and process optimization using response surface methodology

    Science.gov (United States)

    2013-01-01

    Background Isoascorbic acid is a stereoisomer of L-ascorbic acid, and widely used as a food antioxidant. However, its highly hydrophilic behavior prevents its application in cosmetics or fats and oils-based foods. To overcome this problem, D-isoascorbyl palmitate was synthesized in the present study for improving the isoascorbic acid’s oil solubility with an immobilized lipase in organic media. The structural information of synthesized product was clarified using LC-ESI-MS, FT-IR, 1H and 13C NMR analysis, and process parameters for high yield of D-isoascorbyl palmitate were optimized by using One–factor-at-a-time experiments and response surface methodology (RSM). Results The synthesized product had the purity of 95% and its structural characteristics were confirmed as isoascorbyl palmitate by LC-ESI-MS, FT-IR, 1H, and 13C NMR analysis. Results from “one–factor-at-a-time” experiments indicated that the enzyme load, reaction temperature and D-isoascorbic-to-palmitic acid molar ratio had a significant effect on the D-isoascorbyl palmitate conversion rate. 95.32% of conversion rate was obtained by using response surface methodology (RSM) under the the optimized condition: enzyme load of 20% (w/w), reaction temperature of 53°C and D- isoascorbic-to-palmitic acid molar ratio of 1:4 when the reaction parameters were set as: acetone 20 mL, 40 g/L of molecular sieves content, 200 rpm speed for 24-h reaction time. Conclusion The findings of this study can become a reference for developing industrial processes for the preparation of isoascorbic acid ester, which might be used in food additives, cosmetic formulations and for the synthesis of other isoascorbic acid derivatives. PMID:23835418

  18. The Response Surface Methodology speeds up the search for optimal parameters in the photoinactivation of E. coli by Photodynamic Therapy.

    Science.gov (United States)

    Amaral, Larissa S; Azevedo, Eduardo B; Perussi, Janice R

    2018-02-27

    Antimicrobial Photodynamic Inactivation (a-PDI) is based on the oxidative destruction of biological molecules by reactive oxygen species generated by the photo-excitation of a photosensitive molecule. When the a-PDT is performed along with the use of mathematical models, the optimal conditions for maximum inactivation are easily found. Experimental designs allow a multivariate analysis of the experimental parameters. This is usually made using a univariate approach, which demands a large number of experiments, being time and money consuming. This paper presents the use of the response surface methodology for improving the search for the best conditions to reduce E. coli survival levels by a-PDT using methylene blue (MB) and toluidine blue (TB) as photosensitizers and white light. The goal was achieved by analyzing the effects and interactions of the three main parameters involved in the process: incubation time (IT), photosensitizer concentration (C PS ), and light dose (LD). The optimization procedure began with a full 2 3 factorial design, followed by a central composite one, in which the optimal conditions were estimated. For MB, C PS was the most important parameter followed by LD and IT whereas, for TB, the main parameter was LD followed by C PS and IT. Using the estimated optimal conditions for inactivation, MB was able to inactivate 99.999999% CFU mL -1 of E. coli with IT of 28 min, LD of 31 J cm -2 , and C PS of 32 μmol L -1 , while TB required 18 min, 39 J cm -2 , and 37 μmol L -1 . The feasibility of using the response surface methodology with a-PDT was demonstrated, enabling enhanced photoinactivation efficiency and fast results with a minimal number of experiments. Copyright © 2018. Published by Elsevier B.V.

  19. Enhanced Production of a Novel Cyclic Hexapeptide Antibiotic (NW-G01 by Streptomyces alboflavus 313 Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Wenjun Wu

    2012-04-01

    Full Text Available NW-G01, produced by Streptomyces alboflavus 313, is a novel cyclic hexapeptide antibiotic with many potential applications, including antimicrobial activity and antitumor agents. This study developed a system for optimizing medium components in order to enhance NW-G01 production. In this study, Plackett-Burman design (PBD was used to find the key ingredients of medium components, and then response surface methodology (RSM was implemented to determine their optimal concentrations. The results of PBD revealed that the crucial ingredients related to the production of NW-G01 were (NH42SO4, peptone and CaCO3. A prediction model has been built in the experiments of central composite design and response surface methodology, and its validation has been further verified. The optimal medium composition was determined (g/L: corn starch 15, glucose 15, peptone 3.80, (NH42SO4 0.06, NaCl 1.5, CaCO3 1.30, MgSO4·7H2O 0.015, K2HPO4·3H2O 0.015, MnCl2·4H2O 0.015, FeSO4·7H2O 0.015, and ZnSO4·7H2O 0.015. Compared with NW-G01 production (5.707 mg/L in non-optimized fermentation medium, the production of NW-G01 (15.564 mg/L in optimized fermentation medium had a 2.73-fold increase.

  20. X-ray detection capabilities of plastic scintillators incorporated with hafnium oxide nanoparticles surface-modified with phenyl propionic acid

    Science.gov (United States)

    Hiyama, Fumiyuki; Noguchi, Takio; Koshimizu, Masanori; Kishimoto, Shunji; Haruki, Rie; Nishikido, Fumihiko; Yanagida, Takayuki; Fujimoto, Yutaka; Aida, Tsutomu; Takami, Seiichi; Adschiri, Tadafumi; Asai, Keisuke

    2018-01-01

    We synthesized plastic scintillators incorporated with HfO2 nanoparticles as detectors for X-ray synchrotron radiation. Nanoparticles with sizes of less than 10 nm were synthesized with the subcritical hydrothermal method. The detection efficiency of high-energy X-ray photons improved by up to 3.3 times because of the addition of the nanoparticles. Nanosecond time resolution was successfully achieved for all the scintillators. These results indicate that this method is applicable for the preparation of plastic scintillators to detect X-ray synchrotron radiation.

  1. Surface Protonation at the Rutile (110) Interface: Explicit Incorporation of Solvation Structure within the Refined MUSIC Model Framework

    International Nuclear Information System (INIS)

    Machesky, Michael L.; Predota, M.; Wesolowski, David J.

    2008-01-01

    The detailed solvation structure at the (110) surface of rutile (α-TiO 2 ) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model framework to predict surface oxygen protonation constants. Quantum mechanical molecular dynamics (QMD) simulations in the presence of freely dissociable water molecules produced H-bond distributions around deprotonated surface oxygens very similar to those obtained by CMD with nondissociable SPC/E water, thereby confirming that the less computationally intensive CMD simulations provide accurate H-bond information. Utilizing this H-bond information within the refined MUSIC model, along with manually adjusted Ti-O surface bond lengths that are nonetheless within 0.05 (angstrom) of those obtained from static density functional theory (DFT) calculations and measured in X-ray reflectivity experiments (as well as bulk crystal values), give surface protonation constants that result in a calculated zero net proton charge pH value (pHznpc) at 25 C that agrees quantitatively with the experimentally determined value (5.4 ± 0.2) for a specific rutile powder dominated by the (110) crystal face. Moreover, the predicted pH znpc values agree to within 0.1 pH unit with those measured at all temperatures between 10 and 250 C. A slightly smaller manual adjustment of the DFT-derived Ti-O surface bond lengths was sufficient to bring the predicted pH znpc value of the rutile (110) surface at 25 C into quantitative agreement with the experimental value (4.8 ± 0.3) obtained from a polished and annealed rutile (110) single crystal surface in contact with dilute sodium nitrate solutions using second harmonic generation (SHG) intensity measurements as a function of ionic strength. Additionally, the H

  2. Surface Protonation at the Rutile (110) Interface: Explicit Incorporation of Solvation Structure within the Refined MUSIC Model Framework

    Energy Technology Data Exchange (ETDEWEB)

    Machesky, Michael L. [Illinois State Water Survey, Champaign, IL; Predota, M. [University of South Bohemia, Czech Republic; Wesolowski, David J [ORNL

    2008-01-01

    The detailed solvation structure at the (110) surface of rutile ({alpha}-TiO{sub 2}) in contact with bulk liquid water has been obtained primarily from experimentally verified classical molecular dynamics (CMD) simulations of the ab initio-optimized surface in contact with SPC/E water. The results are used to explicitly quantify H-bonding interactions, which are then used within the refined MUSIC model framework to predict surface oxygen protonation constants. Quantum mechanical molecular dynamics (QMD) simulations in the presence of freely dissociable water molecules produced H-bond distributions around deprotonated surface oxygens very similar to those obtained by CMD with nondissociable SPC/E water, thereby confirming that the less computationally intensive CMD simulations provide accurate H-bond information. Utilizing this H-bond information within the refined MUSIC model, along with manually adjusted Ti-O surface bond lengths that are nonetheless within 0.05 {angstrom} of those obtained from static density functional theory (DFT) calculations and measured in X-ray reflectivity experiments (as well as bulk crystal values), give surface protonation constants that result in a calculated zero net proton charge pH value (pHznpc) at 25 C that agrees quantitatively with the experimentally determined value (5.4 {+-} 0.2) for a specific rutile powder dominated by the (110) crystal face. Moreover, the predicted pH{sub znpc} values agree to within 0.1 pH unit with those measured at all temperatures between 10 and 250 C. A slightly smaller manual adjustment of the DFT-derived Ti-O surface bond lengths was sufficient to bring the predicted pH{sub znpc} value of the rutile (110) surface at 25 C into quantitative agreement with the experimental value (4.8 {+-} 0.3) obtained from a polished and annealed rutile (110) single crystal surface in contact with dilute sodium nitrate solutions using second harmonic generation (SHG) intensity measurements as a function of ionic

  3. Fabrication of polyester microchannel with functional surface for electro-chromatography - Incorporation of detection devices into the microchip -

    International Nuclear Information System (INIS)

    Uchiyama, Katsumi; Qiu, Jing Miao; Hobo, Toshiyuki

    2001-01-01

    In recent years, new analytical techniques using microchip devise have been extensively studied (micro-TAS). One of the most successful examples is capillary electrophoresis (CE) with glass plate fabricated by photolithography followed by the chemical or physical etching process. Micro CE one of the most excellent separation techniques, performs separations in microchannel formed in appreciate substrate material. We developed a fabrication method for polyester micro channels with aikene alcohol inside the wall of the channel and demonstrated the usefulness of the polymer microchip. Although many researchers have been studying microchannel or micro-devices for analytical use, miniaturization of the total system including sample introduction, separation, detection and data treatment is still under development. Especially, the miniaturization of the detection system will be a hard bar to be overcome. Our method, based upon the in situ polymerization of polyester resin on an appreciate template, can be exported to let some parts incorporated directly into the microchip during the polymerization process. In this paper, we will describe the incorporation of detection components (light emitting diode and optical fiber) into polyester microchip and the application of the microchip to the analysis of amino acids separated by electrophoresis.

  4. An optimized SPE-LC-MS/MS method for antibiotics residue analysis in ground, surface and treated water samples by response surface methodology- central composite design.

    Science.gov (United States)

    Mirzaei, Roya; Yunesian, Masoud; Nasseri, Simin; Gholami, Mitra; Jalilzadeh, Esfandiyar; Shoeibi, Shahram; Bidshahi, Hooshang Shafieyan; Mesdaghinia, Alireza

    2017-01-01

    Antibiotic residues are being constantly identified in environmental waters at low concentration. Growing concern has been expressed over the adverse environmental and human health effects even at low concentration. Hence, it is crucial to develop a multi-residues analytical method for antibiotics to generate a considerable dataset which are necessary in the assessment of aquatic toxicity of environmental waters for aquatic organisms and human health. This work aimed to develop a reliable and sensitive multi-residue method based on high performance liquid chromatography coupled with quadrupole-linear ion trap tandem mass spectrometry (HPLC-MS-MS). The method was optimized and validated for simultaneous determination of four classes of antibiotics including, β-lactam, macrolide, fluoroquinolone and nitro-imidazole in treated, ground and surface water matrices. In order to optimize the solid phase extraction process, main parameters influencing the extraction process including, pH, the volume of elution solvent and the amount of Na 4 EDTA were evaluated. The optimization of extraction process was carried out by response surface methodology using central composite design. Analysis of variance was performed for nine target antibiotics using response surface methodology. The extraction recoveries were found to be sensitive to the independent variables of pH, the volume of elution solvent and the amount of Na 4 EDTA. The extraction process was pH-dependent and pH was a significant model term in the extraction process of all target antibiotics. Method validation was performed in optimum operation conditions in which the recoveries were obtained in the range of 50-117% for seven antibiotics in spiked treated and ground water samples and for six antibiotics in spiked river water samples. Method validation parameters in terms of method detection limit were obtained in the range of 1-10 ng/L in treated water, 0.8-10 ng/L in the ground water and 0.8-25 ng/L in river water

  5. Formulation and in vitro evaluation of mucoadhesive controlled release matrix tablets of flurbiprofen using response surface methodology

    Directory of Open Access Journals (Sweden)

    Ikrima Khalid

    2014-09-01

    Full Text Available The objective of the current study was to formulate mucoadhesive controlled release matrix tablets of flurbiprofen and to optimize its drug release profile and bioadhesion using response surface methodology. Tablets were prepared via a direct compression technique and evaluated for in vitro dissolution parameters and bioadhesive strength. A central composite design for two factors at five levels each was employed for the study. Carbopol 934 and sodium carboxymethylcellulose were taken as independent variables. Fourier transform infrared (FTIR spectroscopy studies were performed to observe the stability of the drug during direct compression and to check for a drug-polymer interaction. Various kinetic models were applied to evaluate drug release from the polymers. Contour and response surface plots were also drawn to portray the relationship between the independent and response variables. Mucoadhesive tablets of flurbiprofen exhibited non-Fickian drug release kinetics extending towards zero-order, with some formulations (F3, F8, and F9 reaching super case II transport, as the value of the release rate exponent (n varied between 0.584 and 1.104. Polynomial mathematical models, generated for various response variables, were found to be statistically significant (P<0.05. The study also helped to find the drug's optimum formulation with excellent bioadhesive strength. Suitable combinations of two polymers provided adequate release profile, while carbopol 934 produced more bioadhesion.

  6. Optimization of Biomass and 5-Aminolevulinic Acid Production by Rhodobacter sphaeroides ATCC17023 via Response Surface Methodology.

    Science.gov (United States)

    Liu, Shuli; Zhang, Guangming; Li, Jianzheng; Li, Xiangkun; Zhang, Jie

    2016-06-01

    Microbial 5-aminolevulinic acid (ALA) produced from wastewater is considered as potential renewable energy. However, many hurdles are needed to be overcome such as the regulation of key influencing factors on ALA yield. Biomass and ALA production by Rhodobacter sphaeroides was optimized using response surface methodology. The culturing medium was artificial volatile fatty acids wastewater. Three additives were optimized, namely succinate and glycine that are precursors of ALA biosynthesis, and D-glucose that is an inhibitor of ALA dehydratase. The optimal conditions were achieved by analyzing the response surface plots. Statistical analysis showed that succinate at 8.56 mmol/L, glycine at 5.06 mmol/L, and D-glucose at 7.82 mmol/L were the best conditions. Under these optimal conditions, the highest biomass production and ALA yield of 3.55 g/L and 5.49 mg/g-biomass were achieved. Subsequent verification experiments at optimal values had the maximum biomass production of 3.41 ± 0.002 g/L and ALA yield of 5.78 ± 0.08 mg/g-biomass.

  7. Magnetite nanoparticles supported on organically modified montmorillonite for adsorptive removal of iodide from aqueous solution: Optimization using response surface methodology.

    Science.gov (United States)

    Jang, Jiseon; Lee, Dae Sung

    2018-02-15

    Magnetite nanoparticles supported on organically modified montmorillonite (MNP-OMMTs) were successfully synthesized by a facile coprecipitation method. The surface of natural clay was modified using a cationic surfactant, hexadecyltrimethylammonium. The synthesized MNP-OMMTs were used as an adsorbent to remove iodide from aqueous solutions. The maximum adsorption capacity of the adsorbent was 322.42mg/g, which is much higher than other previously reported adsorbents for removing iodide in aqueous solution. The experimental data were well fitted to a pseudo-second-order kinetic model, and the adsorption behavior followed the Langmuir isotherm. A thermodynamic study indicated that iodide adsorption was spontaneous and endothermic. The individual and combined effects of key process parameters (pH, temperature, and initial iodide concentration) were studied using a response surface methodology. The maximum iodide removal efficiency of 93.81% was obtained under the optimal conditions of pH3.9, a temperature of 41.3°C, and an initial iodide concentration of 113.8mg/L. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Biodegradation of bispyribac sodium by a novel bacterial consortium BDAM: Optimization of degradation conditions using response surface methodology.

    Science.gov (United States)

    Ahmad, Fiaz; Anwar, Samina; Firdous, Sadiqa; Da-Chuan, Yin; Iqbal, Samina

    2018-05-05

    Bispyribac sodium (BS), is a selective, systemic and post emergent herbicide used to eradicate grasses and broad leaf weeds. Extensive use of this herbicide has engendered serious environmental concerns. Hence it is important to develop strategies for bioremediation of BS in a cost effective and environment friendly way. In this study a bacterial consortium named BDAM, comprising three novel isolates Achromobacter xylosoxidans (BD1), Achromobacter pulmonis (BA2), and Ochrobactrum intermedium (BM2), was developed by virtue of its potential for degradation of BS. Different culture conditions (temperature, pH and inoculum size) were optimized for degradation of BS by the consortium BDAM and the mutual interactions of these parameters were analysed using a 2 3 full factorial central composite design (CCD) based on Response Surface Methodology (RSM). The optimal values for temperature, pH and inoculum size were found to be 40 °C, 8 and 0.4 g/L respectively to achieve maximum degradation of BS (85.6%). Moreover, the interactive effects of these parameters were investigated using three dimensional surface plots in terms of maximum fitness function. Importantly, it was concluded that the newly developed consortium is a potential candidate for biodegradation of BS in a safe, cost-effective and environmentally friendly manner. Copyright © 2017. Published by Elsevier B.V.

  9. Sorption of phenol from synthetic aqueous solution by activated saw dust: Optimizing parameters with response surface methodology

    Directory of Open Access Journals (Sweden)

    Omprakash Sahu

    2017-12-01

    Full Text Available Organic pollutants have an adverse effect on the neighboring environment. Industrial activates are the major sources of different organic pollutants. These primary pollutants react with surrounding and forms secondary pollutant, which persists for a long time. The present investigation has been carried out on the surface of activated sawdust for phenol eliminations. The process parameters initial concentration, contact time, adsorbent dose and pH were optimized by the response surface methodology (RSM. The numerical optimization of sawdust (SD, initial concentration 10 mg/l, contact time 1.5 h, adsorbent dose 4 g and pH 2, the optimum response result was 78.3% adsorption. Analysis of variance (ANOVA was used to judge the adequacy of the central composite design and quadratic model found to be suitable. The coefficient of determination values was found to be maximum Adj R2 0.7223, and Pre R2 0.5739 and significant regression at 95% confidence level values.

  10. Multi-objective optimization of PMEDM using response surface methodology coupled with fuzzy based desirability function approach

    Directory of Open Access Journals (Sweden)

    Munmun Bhaumik

    2017-09-01

    Full Text Available Powder mixed electro discharge machining (PMEDM is a hybrid machining process where the electrically conductive powder is mixed into the dielectric fluid to enhance the machining efficiency. In this investigation, PMEDM is performed for the machining of AISI 304 stainless steel when silicon carbide powder is mixed into the kerosene dielectric. Peak current, pulse on time, gap voltage, duty cycle and powder concentration are considered as process parameter while material removal rate (MRR, tool wear rate (TWR and surface roughness (Ra are considered as response. A face centered central composite design (FCCCD based response surface methodology (RSM is applied to design the experiment. A hybrid optimization technique like desirability coupled with fuzzy-logic method is performed to get the optimum level of the multiple performance characteristics. Analysis of variance (ANOVA is performed for the statistical analysis. The result shows that peak current is the most significant parameter for MRR, TWR and Ra. The optimal setting for maximum MRR, minimum TWR and Ra have been obtained by desirability coupled with fuzzy-logic method.

  11. Probing the interactions of organic molecules, nanomaterials, and microbes with solid surfaces using quartz crystal microbalances: methodology, advantages, and limitations.

    Science.gov (United States)

    Huang, Rixiang; Yi, Peng; Tang, Yuanzhi

    2017-06-21

    Quartz crystal microbalances (QCMs) provide a new analytical opportunity and prospect to characterize many environmental processes at solid/liquid interfaces, thanks to their almost real-time measurement of physicochemical changes on their quartz sensor. This work reviews the applications of QCMs in probing the interactions of organic molecules, nanomaterials (NMs) and microbes with solid surfaces. These interfacial interactions are relevant to critical environmental processes such as biofilm formation, fate and transport of NMs, fouling in engineering systems and antifouling practices. The high sensitivity, real-time monitoring, and simultaneous frequency and dissipation measurements make QCM-D a unique technique that helps reveal the interaction mechanisms for the abovementioned processes (e.g., driving forces, affinity, kinetics, and the interplay between surface chemistry and solution chemistry). On the other hand, QCM measurement is nonselective and spatially-dependent. Thus, caution should be taken during data analysis and interpretation, and it is necessary to cross-validate the results using complementary information from other techniques for more quantitative and accurate interpretation. This review summarizes the general methodologies for collecting and analyzing raw QCM data, as well as for evaluating the associated uncertainties. It serves to help researchers gain deeper insights into the fundamentals and applications of QCMs, and provides new perspectives on future research directions.

  12. Modeling of thorium (IV) ions adsorption onto a novel adsorbent material silicon dioxide nano-balls using response surface methodology.

    Science.gov (United States)

    Kaynar, Ümit H; Şabikoğlu, Israfil; Kaynar, Sermin Çam; Eral, Meral

    2016-09-01

    The silicon dioxide nano-balls (nano-SiO2) were prepared for the adsorption of thorium (IV) ions from aqueous solution. The synthesized silicon dioxide nano-balls were characterized by Scanning Electron Microscopy/Energy Dispersive X-ray, X-ray Diffraction, Fourier Transform Infrared and BET surface area measurement spectroscopy. The effects of pH, concentration, temperature and the solid-liquid ratio on the adsorption of thorium by nano-balls were optimized using central composite design of response surface methodology. The interaction between four variables was studied and modelled. Furthermore, the statistical analysis of the results was done. Analysis of variance revealed that all of the single effects found statistically significant on the sorption of Th(IV). Probability F-values (F=4.64-14) and correlation coefficients (R(2)=0.99 for Th(IV)) indicate that model fit the experimental data well. The ability of this material to remove Th(IV) from aqueous solution was characterized by Langmuir, Freunlinch and Temkin adsorption isotherms. The adsorption capacity of thorium (IV) achieved 188.2mgg(-1). Thermodynamic parameters were determined and discussed. The batch adsorption condition with respect to interfering ions was tested. The results indicated that silicon dioxide nano-balls were suitable as sorbent material for adsorption and recovery of Th(IV) ions from aqueous solutions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. The optimization of As(V) removal over mesoporous alumina by using response surface methodology and adsorption mechanism.

    Science.gov (United States)

    Han, Caiyun; Pu, Hongping; Li, Hongying; Deng, Lian; Huang, Si; He, Sufang; Luo, Yongming

    2013-06-15

    The Box-Behnken Design of the response surface methodology was employed to optimize four most important adsorption parameters (initial arsenic concentration, pH, adsorption temperature and time) and to investigate the interactive effects of these variables on arsenic(V) adsorption capacity of mesoporous alumina (MA). According to analysis of variance (ANOVA) and response surface analyses, the experiment data were excellent fitted to the quadratic model, and the interactive influence of initial concentration and pH on As(V) adsorption capacity was highly significant. The predicted maximum adsorption capacity was about 39.06 mg/g, and the corresponding optimal parameters of adsorption process were listed as below: time 720 min, temperature 52.8 °C, initial pH 3.9 and initial concentration 130 mg/L. Based on the results of arsenate species definition, FT-IR and pH change, As(V) adsorption mechanisms were proposed as follows: (1) at pH 2.0, H₃AsO₄ and H₂AsO₄(-) were adsorbed via hydrogen bond and electrostatic interaction, respectively; (2) at pH 6.6, arsenic species (H₂AsO₄(-) and HAsO₄(2-)) were removed via adsorption and ion exchange, (3) at pH 10.0, HAsO₄(2-) was adsorbed by MA via ion exchange together with adsorption, while AsO₄(3-) was removed by ion exchange. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Modelling and experimental investigation of process parameters in WEDM of WC-5.3 % Co using response surface methodology

    Directory of Open Access Journals (Sweden)

    K. Jangra

    2012-11-01

    Full Text Available Tungsten carbide-cobalt (WC-Co composite is a difficult-to-machine material owing to its excellent strength and hardness at elevated temperature. Wire electrical discharge machining (WEDM is a best alternative for machining of WC-Co composite into intricate and complex shapes. Efficient machining of WC-Co composite on WEDM is a challenging task since it involves large numbers of parameters. Therefore, in present work, experimental investigation has been carried out to determine the influence of important WEDM parameters on machining performance of WC-Co composite. Response surface methodology, which is a collection of mathematical and experimental techniques, was utilised to obtain the experimental data. Using face-centered central composite design, experiments were conducted to investigate and correlate the four input parameters: pulse-on time, pulse-off time, servo voltage and wire feed for three output performance characteristics – cutting speed (CS, surface roughness (SR and radial overcut (RoC. Using analysis of variance on experimental data, quadratic vs. two-factor interaction (2FI models have been suggested for CS and RoC while two-factor interaction (2FI has been proposed for SR. Using these mathematical models, optimal parameters can be determined easily for desired performance characteristics, and hence a trade-off can be made among different performance characteristics.

  15. Vibration analysis of bonded double-FGM viscoelastic nanoplate systems based on a modified strain gradient theory incorporating surface effects

    Science.gov (United States)

    Jamalpoor, Ali; Kiani, Ali

    2017-03-01

    On the basis of the modified strain gradient theory, the present paper deals with the theoretical analysis of the free vibration of coupled double-FGM viscoelastic nanoplates by Kelvin-Voigt visco-Pasternak medium. To establish static equilibrium of atoms on the each nanoplate surface, the effects of the surface layers are considered. The properties of material in the thickness direction vary according to the power low distribution. Kirchhoff plate assumption and Hamilton's variational principle are employed to achieve the partial differential equations for three different cases of vibration (out-of-phase, in-phase, and one nanoplate of the system being stationary) and corresponding boundary conditions. Navier's approach which satisfies the simply supported boundary conditions applied to analytically investigate the size effect on the natural frequencies of double-FGM viscoelastic nanoplate systems. Numerical studies are carried out to illustrate the influence of viscoelastic damping structural of the nanoplates, damping coefficient of the visco-Pasternak medium, independent length scale parameter, aspect ratio, surface properties, and other factors on the frequency behavior system. Some numerical results of this research illustrate that the frequencies may increase or decrease with respect to the sign of the surface properties of FGMs.

  16. Optimization of micropipette fabrication by laser micromachining for application in an ultrafine atmospheric pressure plasma jet using response surface methodology

    International Nuclear Information System (INIS)

    Wang, Tao; Liu, Jingquan; Yang, Bin; Chen, Xiang; Wang, Xiaolin; Yang, Chunsheng

    2016-01-01

    The optimization of the laser micromachining process for special tapered micropipettes was investigated using response surface methodology. Three process parameters for the CO 2 laser-based micropipette puller (P-2000, Sutter Instrument) were chosen as variables, namely heat, velocity and pull. The targeted length L TVS of the tapered variant section with a tip diameter of 10 μ m was taken as a response. The optimum process parameters with L TVS of 7.3 mm were determined by analyzing the response surface three-dimension surface plots. The central composite design was selected to optimize the process variables, and the experimental data were fitted into a reduced cubic polynomial model. The high R 2 value (99.66%) and low coefficient of variation (0.73%) indicated the statistical significance of the model and good precision for the experiment. The optimization result showed that the best parameters were with the heat, velocity and pull values of 850, 53 and 170, respectively. The result was verified by a CO 2 laser-based micropipette puller three times with length L TVS at 7.26 mm, 7.35 mm and 7.36 mm with the same optimized parameters. Then, the application to the ultrafine atmospheric pressure He/O 2 plasma jets was carried out and micro-hole etching of the parylene-C film was realized with length L TVS at 6.29 mm, 7.35 mm and 8.02 mm. The results showed that the micro-plasma jet with an L TVS of 7.35 mm had the minimum applied voltage of 12.7 kV and the minimum micro-etching diameter of 45 μ m with the deepest etching depth of 2.8 μ m. (paper)

  17. How does the femoral cortex depend on bone shape? A methodology for the joint analysis of surface texture and shape.

    Science.gov (United States)

    Gee, A H; Treece, G M; Poole, K E S

    2018-04-01

    In humans, there is clear evidence of an association between hip fracture risk and femoral neck bone mineral density, and some evidence of an association between fracture risk and the shape of the proximal femur. Here, we investigate whether the femoral cortex plays a role in these associations: do particular morphologies predispose to weaker cortices? To answer this question, we used cortical bone mapping to measure the distribution of cortical mass surface density (CMSD, mg/cm 2 ) in a cohort of 125 females. Principal component analysis of the femoral surfaces identified three modes of shape variation accounting for 65% of the population variance. We then used statistical parametric mapping (SPM) to locate regions of the cortex where CMSD depends on shape, allowing for age. Our principal findings were increased CMSD with increased gracility over much of the proximal femur; and decreased CMSD at the superior femoral neck, coupled with increased CMSD at the calcar femorale, with increasing neck-shaft angle. In obtaining these results, we studied the role of spatial normalization in SPM, identifying systematic misregistration as a major impediment to the joint analysis of CMSD and shape. Through a series of experiments on synthetic data, we evaluated a number of registration methods for spatial normalization, concluding that only those predicated on an explicit set of homologous landmarks are suitable for this kind of analysis. The emergent methodology amounts to an extension of Geometric Morphometric Image Analysis to the domain of textured surfaces, alongside a protocol for labelling homologous landmarks in clinical CT scans of the human proximal femur. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  18. Response Surface Methodology and Aspen Plus Integration for the Simulation of the Catalytic Steam Reforming of Ethanol

    Directory of Open Access Journals (Sweden)

    Bernay Cifuentes

    2017-01-01

    Full Text Available The steam reforming of ethanol (SRE on a bimetallic RhPt/CeO2 catalyst was evaluated by the integration of Response Surface Methodology (RSM and Aspen Plus (version 9.0, Aspen Tech, Burlington, MA, USA, 2016. First, the effect of the Rh–Pt weight ratio (1:0, 3:1, 1:1, 1:3, and 0:1 on the performance of SRE on RhPt/CeO2 was assessed between 400 to 700 °C with a stoichiometric steam/ethanol molar ratio of 3. RSM enabled modeling of the system and identification of a maximum of 4.2 mol H2/mol EtOH (700 °C with the Rh0.4Pt0.4/CeO2 catalyst. The mathematical models were integrated into Aspen Plus through Excel in order to simulate a process involving SRE, H2 purification, and electricity production in a fuel cell (FC. An energy sensitivity analysis of the process was performed in Aspen Plus, and the information obtained was used to generate new response surfaces. The response surfaces demonstrated that an increase in H2 production requires more energy consumption in the steam reforming of ethanol. However, increasing H2 production rebounds in more energy production in the fuel cell, which increases the overall efficiency of the system. The minimum H2 yield needed to make the system energetically sustainable was identified as 1.2 mol H2/mol EtOH. According to the results of the integration of RSM models into Aspen Plus, the system using Rh0.4Pt0.4/CeO2 can produce a maximum net energy of 742 kJ/mol H2, of which 40% could be converted into electricity in the FC (297 kJ/mol H2 produced. The remaining energy can be recovered as heat.

  19. Biodiesel Production from Non-Edible Beauty Leaf (Calophyllum inophyllum Oil: Process Optimization Using Response Surface Methodology (RSM

    Directory of Open Access Journals (Sweden)

    Mohammad I. Jahirul

    2014-08-01

    Full Text Available In recent years, the beauty leaf plant (Calophyllum Inophyllum is being considered as a potential 2nd generation biodiesel source due to high seed oil content, high fruit production rate, simple cultivation and ability to grow in a wide range of climate conditions. However, however, due to the high free fatty acid (FFA content in this oil, the potential of this biodiesel feedstock is still unrealized, and little research has been undertaken on it. In this study, transesterification of beauty leaf oil to produce biodiesel has been investigated. A two-step biodiesel conversion method consisting of acid catalysed pre-esterification and alkali catalysed transesterification has been utilized. The three main factors that drive the biodiesel (fatty acid methyl ester (FAME conversion from vegetable oil (triglycerides were studied using response surface methodology (RSM based on a Box-Behnken experimental design. The factors considered in this study were catalyst concentration, methanol to oil molar ratio and reaction temperature. Linear and full quadratic regression models were developed to predict FFA and FAME concentration and to optimize the reaction conditions. The significance of these factors and their interaction in both stages was determined using analysis of variance (ANOVA. The reaction conditions for the largest reduction in FFA concentration for acid catalysed pre-esterification was 30:1 methanol to oil molar ratio, 10% (w/w sulfuric acid catalyst loading and 75 °C reaction temperature. In the alkali catalysed transesterification process 7.5:1 methanol to oil molar ratio, 1% (w/w sodium methoxide catalyst loading and 55 °C reaction temperature were found to result in the highest FAME conversion. The good agreement between model outputs and exp