Using simulation to assess the introduction of technology in a continuous operations process

Purpose – To investigate the role of simulation in the introduction of technology in a continuous operations process. Design/methodology/approach – A case-based research method was chosen with the aim to provide an exemplar of practice and test the proposition that the use of simulation can improve the implementation and running of conveyor systems in continuous process facilities. Findings – The research determines the optimum rate of re-introduction of inventory to a conveyor system generated during a breakdown event. Research limitations/implications – More case studies are required demonstrating the operational and strategic benefits that can be gained by using simulation to assess technology in organisations. Practical implications – A practical outcome of the study was the implementation of a policy for the manual re-introduction of inventory on a conveyor line after a breakdown event had occurred. Originality/value – The paper presents a novel example of the use of simulation to estimate the re-introduction rate of inventory after a breakdown event on a conveyor line. The paper highlights how by addressing this operational issue, ahead of implementation, the likelihood of the success of the strategic decision to acquire the technology can be improved.

Continuous chromatographic biochemical reaction-separation

Combined bioreaction separation studies have been carried out for the first time on a moving port semi-continuous counter-current chromatographic reactor-separator (SCCR-S1) consisting of twelve 5.4cm id x 75cm long columns packed with calcium charged cross-linked polystyrene resin (KORELA V07C). The inversion of sucrose to glucose and fructose in the presence of the enzyme invertase and the biochemIcal synthesis of dextran and fructose from sucrose in the presence of the enzyme dextransucrase were investigated. A dilute stream of the appropriate enzyme in deionised water was used as the eluent stream. The effect of switch time, feed concentration, enzyme activity, eluent rate and enzyme to feed concentration ratio on the combined bioreaction-separation were investigated. For the invertase reaction, at 20.77% w/v sucrose feed concentrations complete conversions were achieved. The enzyme usage was 34% of the theoretical enzyme amount needed to convert an equivalent amount of sucrose over the same time period when using a conventional fermenter. The fructose rich (FRP) and glucose rich (GRP) product purities obtained were over 90%. By operating at 35% w/v sucrose feed concentration and employing the product splitting and recycling techniques, the total concentration and purity of the GRP increased from 32% w/v to 4.6% and from 92.3% to 95% respectively. The FRP concentration also increased from 1.82% w/v to 2.88% w/v. A mathematical model was developed for the combined reaction-separation and used to simulate the continuous inversion of sucrose and product separation using the SCCR-S1. In the biosynthesis of dextran studies, 52% conversion of a 2% w/v sucrose concentration feed was achieved. An average dextran molecular weight of 4 millIon was obtained in the dextran rich (DRP) product stream. The enzyme dextransucrase was purifed successfully using centrifugation and ultrafiltration techniques.

The production of fructose from carbohydrate feedstocks

A review of the general chromatographic theory and of continuous chromatographic techniques has been carried out. Three methods of inversion of sucrose to glucose and fructose in beet molasses were explored. These methods were the inversion of sucrose using the enzyme invertase, by the use of hydrochloric acid and the use of the resin Amberlite IR118 in the H+ form. The preferred method on economic and purity considerations was by the use of the enzyme invertase. The continuous chromatographic separation of inverted beet molasses resulting in a fructose rich product and a product containing glucose and other non-sugars was carried out using a semi-continuous counter-current chromatographic refiner (SCCR6), consisting of ten 10.8cm x 75cm long stainless steel columns packed with a calcium charged 8% cross-linked polystyrene resin Zerolit SRC 14. Based on the literature this is the first time such a continuous separation has been attempted. It was found that the cations present in beet molasses displaced the calcium ions from the resin resulting in poor separation of the glucose and fructose. Three methods of maintaining the calcium form of the resin during the continuous operation of the equipment were established. Passing a solution of calcium nitrate through the purge column for half a switch period was found to be most effective as there was no contamination of the main fructose rich product and the product concentrations were increased by 50%. When a 53% total solids (53 Brix) molasses feedstock was used, the throughput was 34.13kg sugar solids per m3 of resin per hour. Product purities of 97% fructose in fructose rich (FRP) and 96% glucose in the glucose rich (GRP) products were obtained with product concentrations of 10.93 %w/w for the FRP and 10.07 %w/w for the GRP. The effects of flowrates, temperature and background sugar concentration on the distribution coefficients of fructose, glucose, betaine and an ionic component of beet molasses were evaluated and general relationships derived. The computer simulation of inverted beet molasses separations on an SCCR system has been carried out successfully.

Marketing strategy and new product development in the UK credit card industry

The development of new products in today's marketing environment is generally accepted as a requirement for the continual growth and prosperity of organisations. The literature is consequently rich with information on the development of various aspects of good products. In the case of service industries, it can be argued that new service product development is of as least equal importance as it is to organisations that produce tangible goods products. Unlike the new goods product literature, the literature on service marketing practices, and in particular, new service product development, is relatively sparse. The main purpose of this thesis is to examine a number of aspects of new service product development practice with respect to financial services and specifically, credit card financial services. The empirical investigation utilises both a case study and a survey approach, to examine aspects of new service product development industry practice relating specifically to gaps and deficiencies in the literature with respect to the financial service industry. The findings of the empirical work are subsequently examined in the context in which they provide guidance and support for a new normative new service product development model. The study examines the UK credit card financial service product sector as an industry case study and perspective. The findings of the field work reveal that the new service product development process is still evolving, and that in the case of credit card financial services can be seen as a well-structured and well-documented process. New product development can also be seen as an incremental, complex, interactive and continuous process which has been applied in a variety of ways. A number of inferences are subsequently presented.

Adjusting to institutional realities: the 2006 NGO law and its effects on civil society in Russia

Key findings: The paper investigates the impact that the legislative changes of 2006 had on civil society in Russia. This legislation has change the regulatory environment in which civil society actors such as Third Sector Organisations operate. Using the past development of civil society organisations as well as insights about how the institutional environment influences this article illustrates: - the undemocratic nature and motivation of the law and how it exploits the structural weaknesses of civil society - how Third Sector Organisations rationalise and translate the legislative changes into their organisational realities and how this changed or did not change their behaviour - the shift in state-civil society relations away from liberal co-existence into more hierarchical arrangements were Third Sector Organisations are subordinated to the state. These trends have far reaching implications for civil society. The empirical evidence shows that state now manages civil society to meet its own political ends. It also shows that organisations in the field welcome the more engage and directive nature of the Russian state. Why is this important? What does it mean for business or other users? Are there policy implications? The research is important as it shows how Third Sector Organisations have reacted to the legislative changes. Further it provides a basis for interpretation of the potential future development of civil society. Additional it highlights how the continuous process of democratisation in transition economies sometimes might come unstuck. In particular donor agencies will need to consider these trends when disturbing funding to Third Sector Organisations.

New solid bases for biodiesel synthesis

Biodiesel is a promising non-toxic and biodegradable renewable fuel, synthesized by the homogeneous base-catalyzed transesterification of vegetable oils or animal fats with methanol or ethanol. Removal of the base, typically Na or K alkoxide, after reaction is a major problem since aqueous quenching results in stable emulsions and saponification. The use of a solid base catalyst offers several process advantages including the elimination of a quenching step (and associated basic water waste) to isolate the products, and the opportunity to operate in a continuous process. The synthesis and characterization of a series of Li-doped CaO and Mg-Al hydrotalcite solid base catalysts were presented and their physicochemical properties were correlated with their activity in biodiesel synthesis. Both catalysts were effective solid bases for the transesterification of triglycerides to the methyl ester, with catalyst activity related to the electronic properties of Li and Mg dopants. This is an abstract of a paper presented at the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).

A high sensitivity long period grating Mach-Zehnder refractometer

A refractive index sensing system has been demonstrated, which is based upon an in-line fibre long period grating Mach-Zehnder interferometer with a heterodyne interrogation technique. This sensing system has comparable accuracy to laboratory-based techniques used in industry such as high performance liquid chromatography and UV spectroscopy. The advantage of this system is that measurements can be made in-situ for applications in continuous process control. Compared to other refractive index sensing schemes using LPGs, this approach has two main advantages. Firstly, the system relies on a simple optical interrogation system and therefore has the real potential for being low cost, and secondly, so far as we are aware it provides the highest refractive index resolution reported for any fibre LPG device.

Development of a technological innovation capability assessment model:a case study of manufacturing SMEs in Sialkot, Pakistan

Small and Medium Enterprises (SMEs) play an important part in the economy of any country. Initially, a flat management hierarchy, quick response to market changes and cost competitiveness were seen as the competitive characteristics of an SME. Recently, in developed economies, technological capabilities (TCs) management- managing existing and developing or assimilating new technological capabilities for continuous process and product innovations, has become important for both large organisations and SMEs to achieve sustained competitiveness. Therefore, various technological innovation capability (TIC) models have been developed at firm level to assess firms‘ innovation capability level. These models output help policy makers and firm managers to devise policies for deepening a firm‘s technical knowledge generation, acquisition and exploitation capabilities for sustained technological competitive edge. However, in developing countries TCs management is more of TCs upgrading: acquisitions of TCs from abroad, and then assimilating, innovating and exploiting them. Most of the TIC models for developing countries delineate the level of TIC required as firms move from the acquisition to innovative level. However, these models do not provide tools for assessing the existing level of TIC of a firm and various factors affecting TIC, to help practical interventions for TCs upgrading of firms for improved or new processes and products. Recently, the Government of Pakistan (GOP) has realised the importance of TCs upgrading in SMEs-especially export-oriented, for their sustained competitiveness. The GOP has launched various initiatives with local and foreign assistance to identify ways and means of upgrading local SMEs capabilities. This research targets this gap and developed a TICs assessment model for identifying the existing level of TIC of manufacturing SMEs existing in clusters in Sialkot, Pakistan. SME executives in three different export-oriented clusters at Sialkot were interviewed to analyse technological capabilities development initiatives (CDIs) taken by them to develop and upgrade their firms‘ TCs. Data analysed at CDI, firm, cluster and cross-cluster level first helped classify interviewed firms as leader, follower and reactor, with leader firms claiming to introduce mostly new CDIs to their cluster. Second, the data analysis displayed that mostly interviewed leader firms exhibited ‗learning by interacting‘ and ‗learning by training‘ capabilities for expertise acquisition from customers and international consultants. However, these leader firms did not show much evidence of learning by using, reverse engineering and R&D capabilities, which according to the extant literature are necessary for upgrading existing TIC level and thus TCs of firm for better value-added processes and products. The research results are supported by extant literature on Sialkot clusters. Thus, in sum, a TIC assessment model was developed in this research which qualitatively identified interviewed firms‘ TIC levels, the factors affecting them, and is validated by existing literature on interviewed Sialkot clusters. Further, the research gives policy level recommendations for TIC and thus TCs upgrading at firm and cluster level for targeting better value-added markets.

The mechanics of the conform continuous extrusion process

The work describes the programme of activities relating to a mechanical study of the Conform extrusion process. The main objective was to provide a basic understanding of the mechanics of the Conform process with particular emphasis placed on modelling using experimental and theoretical considerations. The experimental equipment used includes a state of the art computer-aided data-logging system and high temperature loadcells (up to 260oC) manufactured from tungsten carbide. Full details of the experimental equipment is presented in sections 3 and 4. A theoretical model is given in Section 5. The model presented is based on the upper bound theorem using a variation of the existing extrusion theories combined with temperature changes in the feed metal across the deformation zone. In addition, constitutive equations used in the model have been generated from existing experimental data. Theoretical and experimental data are presented in tabular form in Section 6. The discussion of results includes a comprehensive graphical presentation of the experimental and theoretical data. The main findings are: (i) the establishment of stress/strain relationships and an energy balance in order to study the factors affecting redundant work, and hence a model suitable for design purposes; (ii) optimisation of the process, by determination of the extrusion pressure for the range of reduction and changes in the extrusion chamber geometry at lower wheel speeds; and (iii) an understanding of the control of the peak temperature reach during extrusion.

Understanding and improving the manufacturing and changeover process in Saudi Arabian business - a multiple case study approach

The importance of the changeover process in the manufacturing industry is becoming widely recognised. Changeover is a complete process of changing between the manufacture of one product to manufacture of an alternative product until specified production and quality rates are reached. The initiatives to improve changeover exist in industry, as better changeover process typically contribute to improved quality performance. A high-quality and reliable changeover process can be achieved through implementation of continuous or radical improvements. This research examines the changeover process of Saudi Arabian manufacturing firms because Saudi Arabia’s government is focused on the expansion of GDP and increasing the number of export manufacturing firms. Furthermore, it is encouraging foreign manufacturing firms to invest within Saudi Arabia. These initiatives, therefore, require that Saudi manufacturing businesses develop the changeover practice in order to compete in the market and achieve the government’s objectives. Therefore, the aim of this research is to discover the current status of changeover process implementation in Saudi Arabian manufacturing businesses. To achieve this aim, the main objective of this research is to develop a conceptual model to understand and examine the effectiveness of the changeover process within Saudi Arabian manufacturing firms, facilitating identification of those activities that affect the reliability and high-quality of the process. In order to provide a comprehensive understanding of this area, this research first explores the concept of quality management and its relationship to firm performance and the performance of manufacturing changeover. An extensive body of literature was reviewed on the subject of lean manufacturing and changeover practice. A research conceptual model was identified based on this review, and focus was on providing high-quality and reliable manufacturing changeover processes during set-up in a dynamic environment. Exploratory research was conducted in sample Saudi manufacturing firms to understand the features of the changeover process within the manufacturing sector, and as a basis for modifying the proposed conceptual model. Qualitative research was employed in the study with semi-structured interviews, direct observations and documentation in order to understand the real situation such as actual daily practice and current status of changeover process in the field. The research instrument, the Changeover Effectiveness Assessment Tool (CEAT) was developed to evaluate changeover practices. A pilot study was conducted by examining the CEAT, proposed for the main research. Consequently, the conceptual model was modified and CEAT was improved in response to the pilot study findings. Case studies have been conducted within eight Saudi manufacturing businesses. These case studies assessed the implementation of manufacturing changeover practice in the lighting and medical products sectors. These two sectors were selected based on their operation strategy which was batch production as well as the fact that they fulfilled the research sampling strategy. The outcomes of the research improved the conceptual model, ultimately to facilitate the firms’ adoption and rapid implementation of a high-quality and reliability changeover during the set-up process. The main finding of this research is that Quality’s factors were considering the lowest levels comparing to the other factors which are People, Process and Infrastructure. This research contributes to enable Saudi businesses to implement the changeover process by adopting the conceptual model. In addition, the guidelines for facilitating implementation were provided in this thesis. Therefore, this research provides insight to enable the Saudi manufacturing industry to be more responsive to rapidly changing customer demands.

Semi-supervised Gaussian process latent variable model with pairwise constraints

In machine learning, Gaussian process latent variable model (GP-LVM) has been extensively applied in the field of unsupervised dimensionality reduction. When some supervised information, e.g., pairwise constraints or labels of the data, is available, the traditional GP-LVM cannot directly utilize such supervised information to improve the performance of dimensionality reduction. In this case, it is necessary to modify the traditional GP-LVM to make it capable of handing the supervised or semi-supervised learning tasks. For this purpose, we propose a new semi-supervised GP-LVM framework under the pairwise constraints. Through transferring the pairwise constraints in the observed space to the latent space, the constrained priori information on the latent variables can be obtained. Under this constrained priori, the latent variables are optimized by the maximum a posteriori (MAP) algorithm. The effectiveness of the proposed algorithm is demonstrated with experiments on a variety of data sets. © 2010 Elsevier B.V.