A comparison of axiomatic design theory and systematic design procedure in the design of a solid state fermenter

Design theories and methodologies are guidelines to develop design solutions. Among many, the Axiomatic design theory (ADT) and Systematic design procedures (SDP) are two well-known approaches to design. For practical applications, the choice of the design methodology is difficult as there is no study to compare them. To close in such gap in literature, this thesis presents a study on comparison of these two design approaches. To facilitate the comparison, design of a solid state fermenter was taken as a vehicle. The fermenter chosen for this study is was used for detoxification of phorbol esters from Jatropha curcas. Jatopha curcas is a woody plant and is one of the major sources for the production of bio-diesel as it is readily available and has unique composition. Processing Jatopha curcas for biodiesel also yields protein rich Jatopha curcas seed cake. This can be used as animal feedstock, cattle fodder or live feed stock. It is however known that phorbol esters present in the seed cake hinder the utilization of the seed cake as live feed stock. Solid state fermentation by fungi is an effective process to denature phorbol esters, which has been demonstrated at the laboratory scale. Development of an industrial scale solid state fermenter (SSF) is necessary. This study applies SDP and ADT the same deign problem of SSF and compared based on the result of the design. It is noted that in ADT, the evaluation of design alternatives neither considers the cost of the system under design nor the delivery time of the system, but SDP does. To make the comparison on the same ground, an extension of ADT enabling it to consider the cost and delivery time (or time) was developed. Several conclusions can be drawn from this study and they are: (1) ADT and SDP are complementary to each other and the one that integrates both is more effective to design; (2) The essence of Axiom 2 of ADT is to evaluate design alternatives with all factors that lead to difficulty to realize the design, but unfortunately the information content in the current ADT literature only considers the functional or quality aspect; (3) Previous reports suggest the presence of zigzag process only in ADT, However in this study it is evident that SDP exercises the zigzag process as well; (4) the proposed formulation of information content by taking into consideration of the quality, cost, time aspects is more effective in design practice as quite often the cost and time are very important aspects to the customer. The contribution of this thesis study is of two-fold. First, the SSF designed in this study is a pilot one in the field of the biochemical process and it has potential to be implemented. Second, this study concludes several unique findings of ADT and SDP with their relationship, which have further resulted in an integrated ADT and SDP design approach and a more complete formulation of information content capable of evaluating design alternatives from all aspects rather than the functional aspect only

Towards resilient supply chain networks

In the past decade, events like 9/11 terror attacks, the recent financial crisis and other major crisis has proved that there is strong interaction and interdependency of a supply chain network with its external environments in various channels and thus a need to focus on building resiliency (in short, the ability of the system to recover from damage or disruption) of the entire network system. Although literature has discussed some way of improving resiliency of an individual firm which is a member of the network system, it lacked to capture a holistic view of the supply chain network. Pertaining to this observation, this work proposes to improve resiliency of a supply chain network from a system’s perspective rather concentrate on an individual firm. For this purpose, this thesis proposes a conceptual framework to promote early identification and timely information of the disruptions arising in a supply chain network and timely sharing of this information among all the members of the network. The key principle emphasized in this thesis is that recovery from an inevitable disruption has a better possibility if a member of the supply chain network has an early indication or knowledge of the upcoming disruption. A discrete event dynamic system simulation tool called Petri nets is utilized to realize the proposed conceptual framework. Furthermore, the practical benefits and implications of the proposed model and tool are demonstrated with help of two case studies. This thesis has several contributions to the field of operation management and supply chain. First, a new paradigm for supply chain management to avoid large scale failures such as financial crisis is available to the field, which may be applied by governments or regulatory bodies. Second, a new framework which allows for a quantitative analysis of failures of an entire supply chain network is available to the field, which is easy to be used. Third, a novel application of Petri nets to this new problem in supply chain management is available

Application of Biosorption for Removal of Heavy Metals from Wastewater

Fresh water accounts for 3% of water resources on the Earth. Human and industrial activities produce and discharge wastes containing heavy metals into the water resources making them unavailable and threatening human health and the ecosystem. Conventional methods for the removal of metal ions such as chemical precipitation and membrane filtration are extremely expensive when treating large amounts of water, inefficient at low concentrations of metal (incomplete metal removal) and generate large quantities of sludge and other toxic products that require careful disposal. Biosorption and bioaccumulation are ecofriendly alternatives. These alternative methods have advantages over conventional methods. Abundant natural materials like microbial biomass, agro-wastes, and industrial byproducts have been suggested as potential biosorbents for heavy metal removal due to the presence of metal-binding functional groups. Biosorption is influenced by various process parameters such as pH, temperature, initial concentration of the metal ions, biosorbent dose, and speed of agitation. Also, the biomass can be modified by physical and chemical treatment before use. The process can be made economical by regenerating and reusing the biosorbent after removing the heavy metals. Various bioreactors can be used in biosorption for the removal of metal ions from large volumes of water or effluents. The recent developments and the future scope for biosorption as a wastewater treatment option are discussed

Toward a Resilient Holistic Supply Chain Network System: Concept, Review and Future Direction

The recent financial crisis and other major crises have suggested that there are some strong interactions and interdependence between several supply chains and their external environments in various ways. A set of supply chains that are interdependent is called a holistic supply chain network (H-SCN) in this paper. There is a need to focus on building the resilience (in short, the ability of a system to recover from damage or disruption) of an entire H-SCN as it is believed that such a network system is strongly relevant to the recent economic recession that is triggered by financial crises. The objectives of this paper are to provide a classification of different SCNs in literature, leading to the identification of a new type of SCN system, i.e., an H-SCN, and to discuss the state of knowledge on the resilience of SCNs, particularly of an H-SCN. A systematic review approach is applied in this paper. Another contribution of this paper is the provision of a more comprehensive definition and description of resilient systems, including SCN systems. A final contribution of this paper is the proposal of the future directions of research on resilient SCN systems, particularly resilient H-SCN systems.postprin

Comparative analysis of structural variations due to genome shuffling of Bacillus subtilis VS15 for improved cellulase production

Cellulose is one of the most abundant and renewable biomass products used for the production of bioethanol. Cellulose can be efficiently hydrolyzed by Bacillus subtilis VS15, a strain isolate obtained from decomposing logs. A genome shuffling approach was implemented to improve the cellulase activity of Bacillus subtilis VS15. Mutant strains were created using ethyl methyl sulfonate (EMS), N-Methyl-N′ nitro-N-nitrosoguanidine (NTG), and ultraviolet light (UV) followed by recursive protoplast fusion. After two rounds of shuffling, the mutants Gb2, Gc8, and Gd7 were produced that had an increase in cellulase activity of 128%, 148%, and 167%, respectively, in comparison to the wild type VS15. The genetic diversity of the shuffled strain Gd7 and wild type VS15 was compared at whole genome level. Genomic-level comparisons identified a set of eight genes, consisting of cellulase and regulatory genes, of interest for further analyses. Various genes were identified with insertions and deletions that may be involved in improved celluase production in Gd7.. Strain Gd7 maintained the capability of hydrolyzing wheatbran to glucose and converting glucose to ethanol by fermentation with Saccharomyces cerevisiae of the wild type VS17. This ability was further confirmed by the acidified potassium dichromate (K2Cr2O7) method

Response surface methodology-artificial neural network based optimization and strain improvement of cellulase production by Streptomyces sp.

ABSTRACT Thirty seven different colonies were isolated from decomposing logs of textile industries. From among these, a thermotolerant, grampositive, filamentous soil bacteria Streptomyces durhamensis vs15 was selected and screened for cellulase production. The strain showed clear zone formation on CMC agar plate after Gram’s iodine staining.  Streptomyces durhamensis vs15 was further confirmed for cellulase production by estimating the reducing sugars through dinitrosalicylic acid (DNS) method. The activity was enhanced by sequential mutagenesis using three mutagens of ultraviolet irradiation (UV), N methyl-N’-nitro-N-nitrosoguanidine (NTG) and Ethyl methane sulphonate (EMS). After mutagenesis, the cellulase activity of GC23 (mutant) was improved to 1.86 fold compared to the wild strain (vs15). Optimal conditions for the production of cellulase by the GC 23 strain were evaluated using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Effect of pH, temperature, duration of incubation, , and substrate concentration on cellulase production were evaluated. Optimal conditions for the production of cellulase enzyme using Carboxy Methyl Cellulase as a substrate are 55 oC of temperature, pH of 5.0 and incubation for 40 h. The cellulase activity of the mutant Streptomyces durhamensis GC23 was further optimised to 2 fold of the activity of the wild type by RSM and ANN

The Influence of Dopants on Copper Chloride Catalysts for Ethylene Oxychlorination Reaction

The main aim of this Ph.D. project was to study, understand and improve the current knowledge on the Cu-based catalytic reaction in the conversion of ethylene-to-1,2-dichloroethane (oxychlorination), a crucial intermediate reaction to produce PVC (poly-vinyl chloride) plastic, a second largest commodity. The main concerns of the catalyst (Copper chloride supported on a porous alumina support) are loss of the catalyst (deactivation) and getting 100% desired product (selectivity). Deactivation of the catalyst and production of undesirable chlorinated by-products increase the overall costs of the PVC process and more importantly release high amount of environmentally polluted gases. So, study of this process has two main importances: Economical and environmental. We succeeded firstly in an improved fundamental knowledge about the catalytic system, there on developed a better efficient catalyst by adding selective foreign (technically called as dopants/promoters) metal chlorides. Besides that, the developed fundamental knowledge from this work helped our partner company “INEOS ChlorVinyls Scandinavia” to improve the performance of their industrial process, which had plants in Porsgrunn (Norway) and Stenungsund (Sweden). Copper chloride supported on alumina catalysts doped with other metal chlorides (potassium, caesium, lanthanum, magnesium, lithium and sodium chlorides) which are basically promote the reaction activity and selectivity were subjected to investigation in this work. Main emphasis has been given to study these materials i.e study their surfaces, bulks and the changes in their physical, chemical properties in a fresh material and also during the reaction. For this purpose, we adopted several experimental techniques such as synchrotron radiation techniques (X-rayabsorption spectroscopy, XAS), Infra-red spectroscopy (IR), Ultra-violet spectroscopy (UV), the reaction tests in the home-build reactor set up. The various parameters (such as surface composition, oxidation states (I and II) of copper, their relative fractions, chemical phases of the copper containing species and their red-ox behaviour etc.). By using these several complimentary technique we were able to study all these parameters, which are the main factors which influence the chemistry of the reaction. By studying these materials using XAS, we were able to investigate the how the copper oxidation states, its surroundings and its red-ox behaviour are changing during the reaction vs the dopant added. Investigated these materials using IR, and helped us to develop the better knowledge on how the surface (technically acidity and active sites) sites which are responsible for processing the reaction and also for producing some unwanted by-products, are modified by adding dopant. With this knowledge, we were able to control the speed of the process and also controlling the unwanted products. In short summary, this work developed very fruitful knowledge about the influence of foreign element on the catalytic property of the copper chlorides and in-turn helped to provide a scientific knowledge base for further improving not only this reaction, but also for other reactions which involves red-ox property of copper

Oxychlorination-Dehydrochlorination Chemistry on Bifunctional Ceria Catalysts for Intensified Vinyl Chloride Production

ISSN:1433-7851ISSN:1521-3773ISSN:0570-083