Search results for: production reverse engineering

Authors: Srikanta Bose, S.K. Mazumder

Abstract:

In the present simulation work, an attempt is made to study the switching dynamics of an optically controlled 4HSiC thyristor power semiconductor device with the use of GaAs optically triggered power transistor. The half-cell thyristor has the forward breakdown of 200 V and reverse breakdown of more than 1000 V. The optically controlled thyristor has a rise time of 0.14 μs and fall time of 0.065 μs. The turn-on and turn-off delays are 0.1 μs and 0.06 μs, respectively. In addition, this optically controlled thyristor is used as a control switch for the DC-DC Boost converter. The pn-diode used for the converter has the forward drop of 2.8 V and reverse breakdown of around 400 V.

Keywords: 4H-SiC, Boost converter, Optical triggering, Power semiconductor device, thyristor.

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Authors: Chengjie Wang, Li Yin, Chuanmin Wang

Abstract:

This paper presents a physics-based model for the high-voltage fast recovery diodes. The model provides a good trade-off between reverse recovery time and forward voltage drop realized through a combination of lifetime control and emitter efficiency reduction techniques. The minority carrier lifetime can be extracted from the reverse recovery transient response and forward characteristics. This paper also shows that decreasing the amount of the excess carriers stored in the drift region will result in softer characteristics which can be achieved using a lower doping level. The developed model is verified by experiment and the measurement data agrees well with the model.

Keywords: Emitter efficiency, lifetime control, P-i-N diode, physics-based model

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Authors: R. Usubamatov, M. Z. Abdulmuin

Abstract:

Automated production lines with so called 'hard structures' are widely used in manufacturing. Designers segmented these lines into sections by placing a buffer between the series of machine tools to increase productivity. In real production condition the capacity of a buffer system is limited and real production line can compensate only some part of the productivity losses of an automated line. The productivity of such production lines cannot be readily determined. This paper presents mathematical approach to solving the structure of section-based automated production lines by criterion of maximum productivity.

Keywords: optimization production line, productivity, sections

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Authors: Marco Kennemann, Steffen C. Eickemeyer, Peter Nyhuis

Abstract:

An increasingly dynamic and complex environment poses huge challenges to production enterprises, especially with regards to logistics. The Logistic Operating Curve Theory, developed at the Institute of Production Systems and Logistics (IFA) of the Leibniz University of Hanover, is a recognized approach to describing logistic interactions, nevertheless, it reaches its limits when it comes to the dynamic aspects. In order to facilitate a timely and optimal Logistic Positioning a method is developed for quickly and reliably identifying dynamic processing states.

Keywords: Dynamics, Logistic Operating Curves, Production Logistics, Production Planning and Control

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Authors: Ali Nouri Emamzadeh

Abstract:

The experiment was performed to study the relationship between excreta viscosity and Nitrogen-corrected true metabolisable energy quantities of soybean meals using conventional addition method (CAM) in adult cockerels for 7 d: a 3-d preexperiment and a 4-d experiment period. Results indicated that differences between the excreta viscosity values were (P<0.01) significant for SBMs. The excreta viscosity values were less (P<0.01) for SBMs 6, 2, 8, 1 and 3 than other SBMs. The mean TMEn (kcal/kg) values were significant (P<0.01) between SBMs. The most TMEn values were (P<0.01) for SBMs 6, 2, 8 and 1, also the lowest TMEn values were (P<0.01) for SBMs 3, 7, 4, 9 and 5. There was a reverse linear relationship between the values of excreta viscosity and TMEn in SBMs. In conclusion, there was a reverse linear relationship between the values of excreta viscosity and TMEn in SBMs probably due to their various soluble NSPs.

Keywords: soybean meals (SBMs), Nitrogen-corrected true metabolisable energy (TMEn), viscosity

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Authors: Hai-Qing Xie, Yun Zeng, Yong-Hong Yan, Jian-Ping Zeng, Tai-Hong Wang

Abstract:

Photo-BJMOSFET (Bipolar Junction Metal-Oxide- Semiconductor Field Effect Transistor) fabricated on SOI film was proposed. ITO film is adopted in the device as gate electrode to reduce light absorption. Depletion region but not inversion region is formed in film by applying gate voltage (but low reverse voltage) to achieve high photo-to-dark-current ratio. Comparisons of photoelectriccharacteristics executed among VGK=0V, 0.3V, 0.6V, 0.9V and 1.0V (reverse voltage VAK is equal to 1.0V for total area of 10×10μm2). The results indicate that the greatest improvement in photo-to-dark-current ratio is achieved up to 2.38 at VGK=0.6V. In addition, photo-BJMOSFET is compatible with CMOS integration due to big input resistance

Keywords: Photo-BJMOSFET, Responsivity, Sensitivity, Spectral response.

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Authors: Govind Sharan Dangayach, Himanshu Bhatt

Abstract:

The paper attempts to overcome the fluctuations occurring in demand of the components in an automotive sector company. Resource and time being the strict constraints, the production is not able to match the pace of the fluctuating demand. So, we introduce some production schedules that help in meeting out the required demand. The merits and demerits of the approaches are also highlighted.

Keywords: Production scheduling, Demand rise, Capacity constrained resource (CCR), Overtime.

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Authors: G. Schuh, T. Potente, D. Kupke, S. Ivanescu

Abstract:

As German companies roll out their standardized production systems to offshore manufacturing plants, they face the challenge of implementing them in different cultural environments. Studies show that the local adaptation is one of the key factors for a successful implementation. Thus the question arises of where the line between standardization and adaptation can be drawn. To answer this question the influence of culture on production systems is analysed in this paper. The culturally contingent components of production systems are identified. Also the contingency factors are classified according to their impact on the necessary adaptation changes and implementation effort. Culturally specific decision making, coordination, communication and motivation patterns require one-time changes in organizational and process design. The attitude towards rules requires more intense coaching and controlling. Lastly a framework is developed to depict standardization and adaption needs when transplanting production systems into different cultural environments.

Keywords: Culture, influence of national culture on production systems, lean production, production systems.

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Authors: J. Ranogajec, O. Rudic, S. Pasalic, S. Vucetic, D. Cjepa

Abstract:

The paper involves a chain of activities from synthesis, establishment of the methodology for characterization and testing of novel protective materials through the pilot production and application on model supports. It summarizes the results regarding the development of the pilot production protocol for newly developed self-cleaning materials. The optimization of the production parameters was completed in order to improve the most important functional properties (mineralogy characteristics, particle size, self-cleaning properties and photocatalytic activity) of the newly designed nanocomposite material.

Keywords: Cultural heritage. Materials compatibility. Pilot production. Self-cleaning.

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Authors: F. Keller, G. Reinhart

Abstract:

The efficient and economic allocation of resources is one main goal in the field of production planning and control. Nowadays, a new variable gains in importance throughout the planning process: Energy. Energy-efficiency has already been widely discussed in literature, but with a strong focus on reducing the overall amount of energy used in production. This paper provides a brief systematic approach, how energy-supply-orientation can be used for an energy-cost-efficient production planning and thus combining the idea of energy-efficiency and energy-flexibility.

Keywords: Production planning and control, energy, efficiency, flexibility.

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Authors: Seung Woo Lee, So Jeong Nam, Jai-Kyung Lee

Abstract:

It can be said that the business sector is faced with a range of challenges–a rapidly changing business environment, an increase and diversification of customers- demands and the consequent need for quick response–for having in place flexible management and production info systems. As a matter of fact, many manufacturers have adopted production info management systems such as MES and ERP. Nevertheless, managers are having difficulties obtaining ever-changing production process information in real time, or responding quickly to any change in production related needs on the basis of such information. This is because they rely on poor production info systems which are not capable of providing real-time factory settings. If the manufacturer doesn-t have a capacity for collecting or digitalizing the 4 Ms (Man, Machine, Material, Method), which are resources for production, on a real time basis, it might to difficult to effectively maintain the information on production process. In this regard, this paper will introduce some new alternatives to the existing methods of collecting the 4 Ms in real time, which are currently comprise the production field.

Keywords: 4M, Acquisition of Data on shop-floor, Real-time machine interface

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Authors: Said M. Easa, Shinya Kikuchi

Abstract:

When the profile information of an existing road is missing or not up-to-date and the parameters of the vertical alignment are needed for engineering analysis, the engineer has to recreate the geometric design features of the road alignment using collected profile data. The profile data may be collected using traditional surveying methods, global positioning systems, or digital imagery. This paper develops a method that estimates the parameters of the geometric features that best characterize the existing vertical alignments in terms of tangents and the expressions of the curve, that may be symmetrical, asymmetrical, reverse, and complex vertical curves. The method is implemented using an Excel-based optimization method that minimizes the differences between the observed profile and the profiles estimated from the equations of the vertical curve. The method uses a 'wireframe' representation of the profile that makes the proposed method applicable to all types of vertical curves. A secondary contribution of this paper is to introduce the properties of the equal-arc asymmetrical curve that has been recently developed in the highway geometric design field.

Keywords: Optimization, parameters, data, reverse, spreadsheet, vertical curves

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Authors: Manduth Ramchander

Abstract:

Evaluating expressions involving multiplication and division can give rise to the fallacy that brackets can be arbitrarily inserted into expressions involving multiplication and division. The aim of this article was to draw upon mathematical theory to prove that brackets cannot be arbitrarily inserted into expressions involving multiplication and division and in particular in expressions where division precedes multiplication. In doing so, it demonstrates that the notion that two different answers are possible, when evaluating expressions involving multiplication and division, is indeed a false one. Searches conducted in a number of scholarly databases unearthed the rules to be applied when removing brackets from expressions, which revealed that consideration needs to be given to sign changes when brackets are removed. The rule pertaining to expressions involving multiplication and division was then extended upon, in its reverse format, to prove that brackets cannot be arbitrarily inserted into expressions involving multiplication and division. The application of the rule demonstrates that an expression involving multiplication and division can have only one correct answer. It is recommended that both the rule and its reverse be included in the curriculum, preferably at the juncture when manipulation with brackets is introduced.

Keywords: Brackets, multiplication, division, operations, order.

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Authors: S. Kreitlein, N. Eder, A. Syed-Khaja, J. Franke

Abstract:

The importance of energy efficiency within the production processes increases steadily. For a comprehensive assessment of energy efficiency within the production process, unfortunately no tools exist or have been developed yet. Therefore the Institute for Factory Automation and Production Systems at the Friedrich-Alexander-University Erlangen-Nuremberg has developed two methods with the goal of achieving transparency and a quantitative assessment of energy efficiency namely EEV (Energy Efficiency Value) and EPE (Energetic Process Efficiency). This paper describes the basics and state-of-the-art as well as the developed approaches.

Keywords: Energy efficiency, energy efficiency value, energetic process efficiency, production.

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Authors: Sebastian Bertsch

Abstract:

In the past decades, the environment of production companies showed a permanent increase in dynamic and volatility in the form of demand fluctuations, new technologies or global crises. As a reaction to these new requirements, changeability of production systems came into attention. A changeable production system can adapt to these changes quickly and with little effort. Even though demand for changeable production exists for some time, the practical application is still insufficient.

To overcome this deficit, a three year research project at the Department of Production Systems and Logistics at the Leibniz University of Hanover/ Germany was initiated. As a result of this project, different concepts have been developed to design production changeable. An excerpt of the results will be presented in this paper. An eight step procedure will be presented to design the changeability of production logistics. This procedure has been applied at a German manufacturer of high demanding weighing machines. The developed procedure, their application in industry, as well as the major results of the application will be presented.

Keywords: Changeability, Change Drivers, Production Logistics.

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Authors: K. Knüppel, G. Meyer, P. Nyhuis

Abstract:

The increasing interconnectedness and complexity of  production processes raise the susceptibility of production systems to  failure. Therefore, the ability to respond quickly to failures is  increasingly becoming a competitive factor. The research project  "Sustainable failure management in manufacturing SMEs" is  developing a methodology to identify failures in the production and  select preventive and reactive measures in order to correct failures  and to establish sustainable failure management systems.

 

Keywords: Failure categorization, failure management, logistic performance, production optimization.

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Authors: Michael Grigutsch, Marco Kennemann, Peter Nyhuis

Abstract:

Due to the recovering global economy, enterprises are increasingly focusing on logistics. Investing in logistic measures for a production generates a large potential for achieving a good starting point within a competitive field. Unlike during the global economic crisis, enterprises are now challenged with investing available capital to maximize profits. In order to be able to create an informed and quantifiably comprehensible basis for a decision, enterprises need an adequate model for logistically and monetarily evaluating measures in production. The Collaborate Research Centre 489 (SFB 489) at the Institute for Production Systems (IFA) developed a Logistic Information System which provides support in making decisions and is designed specifically for the forging industry. The aim of a project that has been applied for is to now transfer this process in order to develop a universal approach to logistically and monetarily evaluate measures in production.

Keywords: Measures in Production, Logistic Operating Curves, Transfer Functions, Production Logistics

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Authors: Baby Joseph, Sankarganesh Palaniyandi

Abstract:

The enzyme alkaline protease production was determined under solid state fermentation using the soil bacteria Serratia marcescens sp7. The maximum production was obtained from wheat bran medium than ground nut shell and chemically defined medium. The physiological fermentation factors such as pH of the medium (pH 8), Temperature (40oC) and incubation time (48 hrs) played a vital role in alkaline protease production in all the above. 100Mm NaCl has given better resolution during elution of the enzymes. The enzyme production was found to be associated with growth of the bacterial culture.

Keywords: Alkaline protease, Wheat bran, Ground nut shell, Serratia marcescens

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Authors: M. Habchi, S. M. Mesli, M. Kotbi

Abstract:

A structural study of an aqueous electrolyte whose experimental results are available. It is a solution of LiCl-6H2O type at glassy state (120K) contrasted with pure water at room temperature by means of Partial Distribution Functions (PDF) issue from neutron scattering technique. Based on these partial functions, the Reverse Monte Carlo method (RMC) computes radial and angular correlation functions which allow exploring a number of structural features of the system. The obtained curves include some artifacts. To remedy this, we propose to introduce a screened potential as an additional constraint. Obtained results show a good matching between experimental and computed functions and a significant improvement in PDFs curves with potential constraint. It suggests an efficient fit of pair distribution functions curves.

Keywords: RMC simulation; Screened potential; partial and pair distribution functions; glassy and liquid state

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Authors: Mehmet Savsar

Abstract:

This paper presents a model for an unreliable production line, which is operated according to demand with constant work-in-process (CONWIP). A simulation model is developed based on the discrete model and several case problems are analyzed using the model. The model is utilized to optimize storage space capacities at intermediate stages and the number of kanbans at the last stage, which is used to trigger the production at the first stage. Furthermore, effects of several line parameters on production rate are analyzed using design of experiments.

Keywords: Production line simulator, Push-pull system, JIT system, Constant WIP, Machine failures.

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Authors: Behrouz Afshar Nadjafi

Abstract:

Extensive research has been devoted to economic production quantity (EPQ) problem. However, no attention has been paid to problems where production period length is constrained. In this paper, we address the problem of deciding the optimal production quantity and the number of minor setups within each cycle, in which, production period length is constrained but a minor setup is possible for pass the constraint. A mathematical model is developed and Iterated Local Search (ILS) is proposed to solve this problem. Finally, solution procedure illustrated with a numerical example and results are analyzed.

Keywords: EPQ, Inventory control, minor setup, ILS.

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Authors: Amir Azizi, Amir Yazid B. Ali, Loh Wei Ping

Abstract:

Throughput is an important measure of performance of production system. Analyzing and modeling of production throughput is complex in today-s dynamic production systems due to uncertainties of production system. The main reasons are that uncertainties are materialized when the production line faces changes in setup time, machinery break down, lead time of manufacturing, and scraps. Besides, demand changes are fluctuating from time to time for each product type. These uncertainties affect the production performance. This paper proposes Bayesian inference for throughput modeling under five production uncertainties. Bayesian model utilized prior distributions related to previous information about the uncertainties where likelihood distributions are associated to the observed data. Gibbs sampling algorithm as the robust procedure of Monte Carlo Markov chain was employed for sampling unknown parameters and estimating the posterior mean of uncertainties. The Bayesian model was validated with respect to convergence and efficiency of its outputs. The results presented that the proposed Bayesian models were capable to predict the production throughput with accuracy of 98.3%.

Keywords: Bayesian inference, Uncertainty modeling, Monte Carlo Markov chain, Gibbs sampling, Production throughput

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Authors: Bashir Ahmmad, Kensaku Kanomata, Fumihiko Hirose

Abstract:

The effect of carbon materials on TiO₂ for the photocatalytic hydrogen gas production from water / alcohol mixtures was investigated. Single walled carbon nanotubes (SWNTs), multi walled carbon nanotubes (MWNTs), carbon nanofiber (CNF), fullerene (FLN), graphite (GP), and graphite silica (GS) were used as co-catalysts by directly mixing with TiO₂. Drastic synergy effects were found with increase in the amount of hydrogen gas by a factor of ca. 150 and 100 for SWNTs and GS with TiO₂, respectively. Moreover, the increment factor of hydrogen production reached to 180, when the mixture of SWNTs and TiO₂ were smashed in an agate mortar before photocatalytic reactions. The order of H₂ gas production for these carbon materials was SWNTs > GS >> MWNTs > FLN > CNF > GP. To maximize the hydrogen production from SWNTs/TiO₂, various parameters of experimental condition were changed. Also, a comparison between Pt/TiO₂, SWNTs/TiO₂ and GS/TiO₂ was made for the amount of H₂ gas production. Finally, the recyclability of SWNTs/TiO₂or GS/TiO₂ was tested.

Keywords: Photocatalysis, carbon materials, alcohol reforming, hydrogen production, titanium oxide.

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Authors: F. Ardestani, S.A. Fatemi, B. Yakhchali, M. Hosseyni, G. Najafpour

Abstract:

Mycophenolic acid “MPA" is a secondary metabolite of Penicillium bervicompactum with antibiotic and immunosuppressive properties. In this study, fermentation process was established for production of mycophenolic acid by Penicillium bervicompactum MUCL 19011 in shake flask. The maximum MPA production, product yield and productivity were 1.379 g/L, 18.6 mg/g glucose and 4.9 mg/L.h respectively. Glucose consumption, biomass and MPA production profiles were investigated during fermentation time. It was found that MPA production starts approximately after 180 hours and reaches to a maximum at 280 h. In the next step, the effects of methionine and acetate concentrations on MPA production were evaluated. Maximum MPA production, product yield and productivity (1.763 g/L, 23.8 mg/g glucose and 6.30 mg/L. h respectively) were obtained with using 2.5 g/L methionine in culture medium. Further addition of methionine had not more positive effect on MPA production. Finally, results showed that the addition of acetate to the culture medium had not any observable effect on MPA production.

Keywords: Penicillium bervicompactum, Methionine, Mycophenolic acid, Submerged culture

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Authors: M. H. M. Rusli, A. Jaffar, M. T. Ali, S. Muhamud @ Kayat

Abstract:

Lean manufacturing is a production philosophy made popular by Toyota Motor Corporation (TMC). It is globally known as the Toyota Production System (TPS) and has the ultimate aim of reducing cost by thoroughly eliminating wastes or muda. TPS embraces the Just-in-time (JIT) manufacturing; achieving cost reduction through lead time reduction. JIT manufacturing can be achieved by implementing Pull system in the production. Furthermore, TPS aims to improve productivity and creating continuous flow in the production by arranging the machines and processes in cellular configurations. This is called as Cellular Manufacturing Systems (CMS). This paper studies on integrating the CMS with the Pull system to establish a Big Island-Pull system production for High Mix Low Volume (HMLV) products in an automotive component industry. The paper will use the build-in JIT system steps adapted from TMC to create the Pull system production and also create a shojinka line which, according to takt time, has the flexibility to adapt to demand changes simply by adding and taking out manpower. This will lead to optimization in production.

Keywords: Big Island layout, Lean manufacturing, Material and Information Flow Chart, Pull system production, TPS.

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Authors: S. F. Wong, W. I. Ho, B. Lin, Q. Huang

Abstract:

ERP has been used in many enterprises for management, the accuracy of the production forecasting module is vital to the decision making of the enterprise, and the profit is affected directly. Therefore, enhancing the accuracy of the production forecasting module can also increase the efficiency and profitability. To deal with a lot of data, a suitable, reliable and accurate statistics model is necessary. LSSVM and Grey System are two main models to be studied in this paper, and a case study is used to demonstrate how the combination model is effective to the result of forecasting.

Keywords: ERP, Grey System, LSSVM, production forecasting.

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Authors: Mohd. Khairil Sailan, Rosilah Hassan, Zuhaizal Zulkifli

Abstract:

Internet Protocol version 4 (IPv4) address is decreasing and a rapid transition method to the next generation IP address (IPv6) should be established. This study aims to evaluate and select the best performance of the IPv6 address network transitionmechanisms, such as IPv4/IPv6 dual stack, transport Relay Translation (TRT) and Reverse Proxy with additional features. It is also aim to prove that faster access can be done while ensuring optimal usage of available resources used during the test and actual implementation. This study used two test methods such asInternet Control Message Protocol (ICMP)ping and ApacheBenchmark (AB) methodsto evaluate the performance.Performance metrics for this study include aspects ofaverageaccessin one second,time takenfor singleaccess,thedata transfer speed and the costof additional requirements.Reverse Proxy with Caching featureis the most efficientmechanism because of it simpler configurationandthe best performerfrom the test conducted.

Keywords: IPv4, IPv6, network transition, apache benchmark andreverse proxy

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Authors: Donglan Zha, Jiansong Si

Abstract:

Because of its flexibility, CES attracts much interest in economic growth and programming models, and the macroeconomics or micro-macro models. This paper focuses on the development, estimating methods of CES production function considering energy as an input. We leave for future research work of relaxing the assumption of constant returns to scale, the introduction of potential input factors, and the generalization method of the optimal nested form of multi-factor production functions.

Keywords: Bias of technical change, CES production function, elasticity of substitution, energy input.

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Authors: Fatemeh Ardestani, Seyed Safa-ali Fatemi, Bagher Yakhchali, Seyed Morteza Hosseyni, Ghasem Najafpour

Abstract:

Mycophenolic acid “MPA" is a secondary metabolite of Penicillium bervicompactum with antibiotic and immunosuppressive properties. In this study, fermentation process was established for production of mycophenolic acid by Penicillium bervicompactum MUCL 19011 in shake flask. The maximum MPA production, product yield and productivity were 1.379 g/L, 18.6 mg/g glucose and 4.9 mg/L.h respectively. Glucose consumption, biomass and MPA production profiles were investigated during fermentation time. It was found that MPA production starts approximately after 180 hours and reaches to a maximum at 280 h. In the next step, the effects of methionine and acetate concentrations on MPA production were evaluated. Maximum MPA production, product yield and productivity (1.763 g/L, 23.8 mg/g glucose and 6.30 mg/L. h respectively) were obtained with using 2.5 g/L methionine in culture medium. Further addition of methionine had not more positive effect on MPA production. Finally, results showed that the addition of acetate to the culture medium had not any observable effect on MPA production

Keywords: Penicillium bervicompactum, Methionine, Mycophenolic acid, Submerged culture.

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Authors: A. Daverey, K. Pakshirajan, P. Sangeetha

Abstract:

Sophorolipids (SLs) production by the yeast Candida bombicola was studied in batch shake flasks using synthetic dairy wastewaters (SDWW) with or without any added external carbon and nitrogen sources. A maximum SLs production of 38.76 g/l was observed with the SDWW supplemented with low cost substrate of sugarcane molasses at 50 g/l and soybean oil at 50 g/l. When the SDWW was supplemented with more costly glucose, yeast extract, urea and soybean oil, the production, however, got lowered to only 29.49 g/l, but with a maximum biomass production of 17.38 g/l together with a complete utilization of the carbon sources.

Keywords: Candida bombicola, dairy wastewater, fat and oil, sophorolipids.

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