Showing papers by "Cranfield University published in 1994"

Restoration of the contact surface in the HLL-Riemann solver

Abstract: The missing contact surface in the approximate Riemann solver of Harten, Lax, and van Leer is restored. This is achieved following the same principles as in the original solver. We also present new ways of obtaining wave-speed estimates. The resulting solver is as accurate and robust as the exact Riemann solver, but it is simpler and computationally more efficient than the latter, particulaly for non-ideal gases. The improved Riemann solver is implemented in the second-order WAF method and tested for one-dimensional problems with exact solutions and for a two-dimensional problem with experimental results.

Characterisation of textile wastewaters ‐ a review

Abstract: The characteristics of wastewater from textile processing operations are comprehensively reviewed. The categorisation of wastewaters proceeds through a consideration of the nature of the various industrial processes employed by the industry and the chemicals associated with these operations. Chemical pollutants arise both from the raw material itself and a broad range of additives used to produce the finished product. The industrial categories considered include sizing and desizing, weaving, scouring, bleaching, mercerizing, carbonizing, fulling, dyeing and finishing. Pollutants of concern range from non‐biodegradable highly‐coloured organic dyes to pesticides from special finishes such as insect‐proofing. It is evident that the textile wastewater chemical composition is subject to considerable change due to both the diversity in the textile processes employed and the range of chemicals employed within each industrial category.

Ceos' cognitive maps and the scope of the organization

Abstract: In this paper, CEOs are considered as 'cognizers' charged with integrating views in the top management team; a role which should require high cognitive complexity especially in diversified multinational corporations. A methodology for studying top managers' cognitive complexity is described and then applied to a sample of 26 CEOs. The CEOs' cognitive maps of the structure and of the dynamics of their industry are analyzed in terms of their degree of complexity, in relation to the breadth of the business portfolio of the firm, its geographic scope and the links the firm has with foreign parents. The results of this exploratory test generally confirm the principle of requisite cognitive complexity, and reveal a new set of more precise hypotheses linking particular dimensions of the scope of the firm with particular dimensions of CEOs' cognitive complexity. Strategic problems and strategic decision making are complex (Mintzberg, Raisinghani, and Theo- ret, 1976; Lyles and Mitroff, 1981; Mason and Mitroff, 1981; Cray et al., 1991). Environments become more complex as international compe- tition and knowledge flows develop (Porter, 1986; Melin, 1992); and the scope of some diversified multinational companies (DMNCs) adds even greater complexity (Prahalad and Doz, 1987). Firms, industries and business environments may be considered as systems and their level of complexity can be conceived of in terms of systems theory: the number of elements in the system and the number of links between

Exploring the mental models of competitive strategists: the case for a processual approach

Abstract: Recently there have been a number of studies published which seek to further our understanding of the competitive structures of markets. These studies have used aggregated perceptual data in an attempt to uncover industry-level mental models of business environments. In this article we argue that such studies are predicated on the assumption that there are high levels of consensus within and between organizations in a given industry concerning the bases of competition and the positioning of particular organizations. In the present study we employ a similar methodology but focus on the mental models of individuals in order to examine empirically the nature and extent of such consensus. the research was carried out in the UK grocery retailing industry. Twenty-three managers from two organizations were each interviewed using a variant of the cognitive taxonomic interview procedures devised by Porac and his associates. the study revealed considerable variation in terms of the nature of the cognitive categories elicited from the participants and the overall complexity of their taxonomies relating to competitive structures, both within and between the organizations. However, the study also revealed considerable intra-organizational agreement regarding the categories which describe the self-identity of the research participants’organizations and their major competitors. We consider the implications of these findings for understanding processes of strategy development and implementation in organizations.

Defining Competitiveness: A Holistic Approach

Abstract: Although the notion of competitiveness lies at the heart of business strategy development, its definition is often vague and does not lend itself to a measurement process. The competitiveness of an organization depends on a number of factors which are interrelated and cannot be looked at in isolation. The main factors include: customer values, shareholder values and ability to act and react within a competitive environment. Proposes a holistic approach for defining competitiveness together with a mapping process which encompasses different dimensions of competitiveness. The mapping process enables the measurement of competitiveness while highlighting the strengths, weaknesses, opportunities and threats within a competitive environment which form the basis of business strategy formulation.

Use of Lactobacillus plantarum LPCO10, a Bacteriocin Producer, as a Starter Culture in Spanish-Style Green Olive Fermentations

Abstract: Bacteriocin-producing Lactobacillus plantarum LPCO10 and its non-bacteriocin-producing, bacteriocinimmune derivative, L. plantarum 55-1, were evaluated separately for growth and persistence in natural Spanish-style green olive fermentations. Both strains were genetically marked and selectively enumerated using antibiotic-containing media. Plasmid profile and bacteriocin production (bac+) were used as additional markers. When olive brines were inoculated at 105 CFU/ml, the parent strain, LPCO10, proliferated to dominate the epiphytic microflora, sharing high population levels with other spontaneously occurring lactobacilli and persisting throughout the fermentation (12 weeks). In contrast, the derivative strain could not be isolated after 7 weeks. Stability of both plasmid profile and bac+ (LPCO10 strain) or bac- (55-1 strain) phenotype was shown by L. plantarum LPCO10 and L. plantarum 55-1 isolated throughout the fermentation. Bacteriocin activity could be found in the L. plantarum LPCO10-inoculated brines only after ammonium sulfate precipitation and concentration (20 times) of the final brine. Spontaneously occurring lactobacilli and lactic coccus populations, which were isolated from each of the fermenting brines studied during this investigation, were shown to be sensitive to the bacteriocins produced by L. plantarum LPCO10 when tested by the drop diffusion test. The declines in both pH and glucose levels throughout the fermentative process were similar in L. plantarum LPCO10- and in L. plantarum 55-1-inoculated brines and were comparable to the declines in the uninoculated brines. However, the final concentration of lactic acid in L. plantarum LPCO10-inoculated brines was higher than in the L. plantarum 55-1-inoculated brines and uninoculated brines. These results indicated that L. plantarum LPCO10 may be useful as a starter culture to control the lactic acid fermentation of Spanish-style green olives.

A model for particle cavitation in rubber-toughened plastics

Abstract: An energy-balance criterion for cavitation of rubber particles, which was proposed in an earlier paper [A. Lazzeri and C. B. Bucknall, J. Mater. Sci.28 (1993) 6799], is developed by including a term for the energy stored in the matrix and released during expansion of the voids. The model relates the critical volume strain at cavitation to the radius of the rubber particle, and to the shear modulus, surface energy and failure strain of the rubber. The effects of temperature, strain rate and type of stress field upon cavitation behaviour and the resulting toughness of the two-phase polymer are discussed in terms of the model.

Precision farming: an introduction

Abstract: Traditional arable management practice has tended to manage fields uniformly and has tended to ignore the inherent spatial variability found on most farms. This has been exacerbated by the increase...

Continuous analyte monitoring to aid clinical practice

Abstract: Considerable progress has been made in the development of practical glucose sensors for in vivo use. In some designs, the sensor can be replaced by the patient, who "injects" a new sensor into a fresh site using a hypodermic needle. An open-loop hypoglycaemia sensor providing an alarm signal could be available soon, and it would be very useful in the management of diabetes. The sensor for this application would need to function for a minimum period of about 12 hours. Further developments in the glucose sensor area are expected to lead to a comfortable implantable sensor/pump device, which would provide closed loop control for a prolonged period. An acceptable system would be a sensor replaced every 2 to 3 days, coupled with a microprocessor-controlled pump replaced after 2 to 3 years. Further engineering input is needed to design the monitoring and control unit containing the alarm and pump systems. The world market in clinical analysis is about US $6 billion, and covers about 10% of the total expenses for health care. It is in the field of continuous microsensors that future competition for the clinical diagnostic market will take place. Funding in vivo projects is less attractive to industry than the more proven and well-established area of in vitro diagnostics. However, the benefits of in vivo monitoring to the health of the community, and the financial rewards to manufacturers are ultimately great. It is clearly of interest for industry to invest in the development and commercialisation of this high added-value technology. >

Differences in Managerial Cognitions of Competition1

Abstract: SUMMARY It has been assumed that strategic decision making and implementation are both achieved through managers' sharing homogeneous cognitions of competition (e.g. Porac and Thomas, 1990). This paper tested the assumption of homogeneity of cognitions of competition, using a sample of 24 managers from the off-shore pumps industry. A variety of cognitive mapping techniques were used and maps were compared using a self-rating methodology. The results indicated that managers' mental models of competition are diverse, rather than homogeneous, but that this diversity increases as company boundaries are crossed and as functional boundaries are crossed. Therefore, it is concluded that future cognitive studies of competitive industry structures should assume diversity of cognitions rather than homogeneity. Specific propositions with regard to such research are drawn from the findings.

Non-centrosymmetry and second-harmonic generation in Z-type Langmuir–Blodgett films

Abstract: THE principal requirement for materials that exhibit second-harmonic generation—frequency-doubling of light—is that they have a non-centrosymmetric structure. For optically active organic materials, this can be achieved by the use of the Langmuir–Blodgett (LB) technique1,2: amphiphilic molecules comprising a hydrophilic head (the chromophore) and a hydrophobic tail are aligned at an air–water interface, and the resulting ordered monolayer is transferred to an appropriate solid substrate. For practical applications, the non-centrosymmetric structure of the individual mono-layers needs to be maintained across many such layers, but this has been achieved previously for relatively few optically active molecules3–5. Most amphiphiles pack centrosymmetrically, with the layers adopting a head-to-head and tail-to-tail 'Y-type' structure6. To enforce a non-centrosymmetric structure, it becomes necessary to intersperse the optically active layers with another material7–12. Here we demonstrate an alternative strategy for achieving macroscopic non-centrosymmetric order in LB multilayers. We find that the addition of a second hydrophobic end-group to the hydrophilic chromophore reduces the tendency of the molecules to invert during deposition, and a head-to-tail 'Z-type' structure can be readily obtained for films containing more than 100 layers.

The “Coping” Capacity Management Strategy in Services and the Influence on Quality Performance

Abstract: Matching supply and demand in services by capacity management has a direct influence on the ability of the service delivery system to achieve service quality and resource productivity targets. Examines some propositions for the influences of capacity management on quality and resource productivity and for managing capacity. In addition to the chase and level strategies for managing capacity in services suggested by Sasser a coping strategy for capacity management is described which aims to improve the overall delivery of service quality while achieving resource productivity targets. Coping is necessary for all organizations at some time. Some research results derived from the experience of a range of service organizations indicate a less than satisfactory handling of the coping situation.

Attitudes and Food Choice Behaviour

Abstract: UK sales of olive oil increased by 15 per cent in real terms between 1986 and 1992. As part of a programme of research investigating the diffusion of the Mediterranean diet in the UK, investigates the reasons behind this rapid acceptance of olive oil in British kitchens through a study of consumers′ attitudes and behaviour regarding its culinary use. The study was designed to establish the salient attitudinal and normative beliefs which consumers associate with olive oil in order to assess the value of those beliefs as predictors of behaviour in respect of olive oil usage. Perceived control was found not to be relevant at an early stage in the study, therefore, the theory of reasoned action (as opposed to planned behaviour) was used as the methodological base. Data were collected by means of a questionnaire completed by 151 subjects. Attitudinal beliefs, especially those concerning flavour enhancement, were found to be important predictors of olive oil usage, casting doubt on the assumption that increased...

A device for determining the sorptivity of soil aggregates

Abstract: Summary A device that infiltrated water over a small circular surface area having a radius ranging between 1.45 mm and 2.5 mm was used to measure the sorptivity of initially air-dry aggregates of size greater than 20 mm. The small infiltration area caused the water uptake to be dominated by capillarity that allowed the use of a simple formula to obtain the sorptivity from the steady-state flow rate that occurred very early after the start of imbibition. The results of measurements of sorptivity made on a fine sand agreed with those obtained from measurements on one-dimensional water infiltration into columns of the sand. Sorptivity measurements on stabilized aggregates of a clay soil and on air-dried field aggregates of a clay soil were easily made. The simplicity and rapidity of the method allowed measurements to be conveniently replicated.

Relationship Marketing – Making the Customer Count

Abstract: The key to success in service business now lies with concentrating on, and retaining, existing customers. Marketing therefore must be seen as a total approach with the customer firmly at the centre. Describes the relationship marketing ladder as the progression from conversion of a prospect into a customer, then into a client, from client to supporter, to advocate and, finally, to partner. Outlines the economic benefits of retaining customers. Emphasizes the link between quality, client retention and profitability.

Effects of KCl concentration on accumulation of acyclic sugar alcohols and trehalose in conidia of three entomopathogenic fungi

Abstract: Beauveria bassiana, Metarhizium anisopliae and Paecilomyces farinosus were grown on Sabouraud Dextrose Agar (SDA) modified with KCl to give a range of water activity (aw) from 0.938 to 0.998. Growth of all three species was optimal at 0.983 aw and growth occurred over the aw range tested. Acyclic sugar alcohol (polyol) and trehalose content of conidia was determined by HPLC and found to vary with species and aw. Conidia of B. bassiana and P. farinosus were found to contain totals of 1.5% and 2.3% polyols respectively at 0.998 aw, and double these amounts at <0.950 aw. Conidia of M. anisopliae contained from 5.7% to 6.8% polyols at each aw tested. In conidia of all three species the predominant polyol was mannitol. The lower molecular weight polyols, arabitol and erythritol, were found to accumulate at reduced aw. Small amounts of glycerol were present in conidia of each species; <15% total polyols. Conidia of B. bassiana and M. anisopliae contained about 0.5% trehalose from 0.970 to 0.998 aw, but only trace amounts below 0.950 aw. Conidia of P. farinosus contained 2.1% trehalose at 0.998 aw and this decreased to <0.1% below 0.950 aw. Potential to manipulate the endogenous reserves of conidia of these biological control agents to enhance viability and desiccation toierance is discussed

Healthy Food Products for Children

Abstract: Explores the relationship between mothers′ purchase of perceived healthy foods, packaging characteristics, and the childrens “pester power” in obtaining attractive or appealing packaging. The results suggest mothers will not buy perceived healthy foods if the packaging is not acceptable. Discusses packaging and marketing strategies.

Hydrogen Embrittlement of Cathodically Protected High-Strength, Low-Alloy Steels Exposed to Sulfate-Reducing Bacteria

Abstract: Hydrogen embrittlement (HE) of two high-strength, low-alloy steels was studied in conditions typical of the marine environment. Double-cantilever beam specimens, heat-treated to produce th...