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Article
Publication date: 1 June 2005

A.V. Kuznetsov and P. Geng

To investigate numerically the settling of small solid particles in a suspension of motile gyrotactic micro‐organisms in order to evaluate the possibility of using…

Abstract

Purpose

To investigate numerically the settling of small solid particles in a suspension of motile gyrotactic micro‐organisms in order to evaluate the possibility of using bioconvection to slow down settling and enhance mixing between particles.

Design/methodology/approach

Numerical computations are performed at the North Carolina Supercomputing Center utilizing an Origin 2400 workstation. A conservative finite‐difference scheme is used to discretize the governing equations. A staggered uniform grid with the stream function and vorticity stored in one set of nodes and the number densities of micro‐organisms and solid particles stored in another set of nodes is utilized. CPU time required to investigate plume development until it attains steady‐state for 36 × 36 uniform mesh is about 50 h.

Findings

It is established that small solid particles that are heavier than water slow down bioconvection. Extremely small particles (nanoparticles) that have negligible settling velocity do not have any noticeable impact on bioconvection, very large particles (that have negligible diffusivity), or very heavy particles (that have very large settling velocity) also do not have any impact on bioconvection because they simply settle at the bottom. However, if the particles are of the optimal size and density (gravitational settling must compete with Brownian diffusion to create an exponential number density distribution of solid particles with the maximum at the bottom of the chamber), these particles can effectively slow down bioconvection.

Research limitations/implications

The question how solid particles may affect the wavelengths of bioconvection patterns requires further investigation.

Practical implications

The finding that solid particles slow down bioconvection may be important in using bioconvection to enhance mixing in fluid microvolumes.

Originality/value

The paper provides a model and numerical data about the effect of bioconvection on mixing of small solid particles. These data are valuable for researches working in fundamental fluid mechanics, multiphase flow, and applications of bioconvection.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 15 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 18 October 2021

John Peter Cooney, David Oloke and Louis Gyoh

This study aims to demonstrate the possibility of showing the functionality of complex microbial groups, within ancient structures within a process of refurbishment on a…

Abstract

Purpose

This study aims to demonstrate the possibility of showing the functionality of complex microbial groups, within ancient structures within a process of refurbishment on a heritage building information modelling (BIM) platform.

Design/methodology/approach

Both a qualitative and qualitative research method will be used throughout, as observational and scientific results will be obtained and collated. This path being; phenomena – acquisition tools – storage – analysis tools – literature. Using this methodology, one pilot study within the scope of demolition and refurbishment, using suitable methods of collecting and managing data (structural or otherwise), will be used and generated by various software and applications. The principle methods used for the identification of such micro-organisms will incorporate a polymerase chain reaction method (PCR), to amplify DNA and to identify any or all spores present. The BIM/historical BIM (HBIM) process will be used to create a remotely-based survey to obtain and collate data using a laser scanner to produce a three-dimensional point cloud model to evaluate and deduce the condition, make-up and stature of the monument. A documentation management system will be devised to enable the development of plain language questions and an exchange information requirement, to identify such documentation required to enable safe refurbishment and to give health and safety guidance. Four data sampling extractions will be conducted, two for each site, within the research, for each of the periods being assessed, that being the Norman and Tudor areas of the monument.

Findings

From laboratory PCR analysis, results show a conclusive presence of micro-organism groups and will be represented within a hierarchical classification, from kingdom to species.

Originality/value

The BIM/HBIM process will highlight results in a graphical form to show data collected, particularly within the PCR application. It will also create standardisation and availability for such data from ancient monuments to make available all data stored, as such analysis becomes substantially important to enable the production of data sets for comparison, from within the framework of this research.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 20 June 2008

Oliver Lange, Marcel Erhard, Christian Teutsch and Joerg Sander

The purpose of this paper is to present a novel microbiological lab robot that facilitates high through‐put sample preparation for rapid state‐of‐the‐art identification.

Abstract

Purpose

The purpose of this paper is to present a novel microbiological lab robot that facilitates high through‐put sample preparation for rapid state‐of‐the‐art identification.

Design/methodology/approach

Development concentrated on two main points: research initially focused on various methods for picking a micro‐organism colony from a petri dish without any medium adhering; and subsequently on completely documenting sample handling with little effort.

Findings

A sensorless system for picking micro‐organisms from a petri dish was engineered and prototyped. A documented process in the demonstrator demonstrates its usability even for certified clinical operations.

Research limitations/implications

The handling of solid phase biological objects is only in its infancy. This research focused on the preparation of samples from micro‐organism colonies for MALDI‐TOF MS. A specific type of gripper was developed to do this. The handling of other biological objects, e.g. from cell cultures or intermediate stages of tissue engineering, is still a largely open field for future research.

Practical implications

New analysis methods often only become accepted when the preparatory processes are also taken into account – highly parallel operations (e.g. MALDI‐TOF MS) are particularly impractical for humans and difficult for data handling to manage. Given the specific demands, only an interdisciplinary team can adapt the automation engineering successfully.

Originality/value

This paper presents an approach to and implementation of the automation of manual operations in biotechnology. It is intended to encourage health professionals, biologists and engineers to jointly research and interdisciplinarily automate complex operations.

Details

Industrial Robot: An International Journal, vol. 35 no. 4
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 April 2001

Linda Everis

Food can contain a variety of micro‐organisms such as the bacteria Salmonella and E. coli and the yeasts and moulds. The presence of micro‐organisms in foodstuffs can…

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Abstract

Food can contain a variety of micro‐organisms such as the bacteria Salmonella and E. coli and the yeasts and moulds. The presence of micro‐organisms in foodstuffs can affect both the safety and quality of the product. Consequently, food manufacturers have developed food processing treatments that help preserve foods, by destroying the micro‐organisms that are present or by injuring them and thus preventing their growth. There are many sites within a bacterial cell that can become damaged when the bacteria are subjected to these food processing treatments. These sites include the genetic material of the cell (DNA, RNA) and also the cell membrane. Some bacteria have developed ways to survive some processing treatments. These include the production of heat shock and cold shock proteins that help the cell function normally under higher or lower temperatures than normal. Some treatments will cause irreparable damage and the cells will be destroyed. However, sometimes the damage will be repairable and the cells are able to repair and recover. The micro‐organisms that are destroyed by processing will not cause subsequent food poisoning or spoilage, but organisms that are injured and become repaired could cause subsequent food spoilage or poisoning. The uninjured cells will be those organisms that are most easily detected and enumerated by current microbiological methods. The results gained from use of these methods are used to assess the risks of food spoilage and safety. However, the injured bacteria must also be accounted for. These organisms can also pose a food safety and/or spoilage risk as they can repair if the conditions become favourable. Therefore suitable test methods to detect bacteria within foodstuffs should be developed.

Details

Nutrition & Food Science, vol. 31 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 25 June 2019

Atul Kumar Ray, Vasu B., O. Anwar Beg, R.S.R. Gorla and P.V.S.N. Murthy

This paper aims to numerically investigate the two-dimensional unsteady laminar magnetohydrodynamic bioconvection flow and heat transfer of an electrically conducting…

Abstract

Purpose

This paper aims to numerically investigate the two-dimensional unsteady laminar magnetohydrodynamic bioconvection flow and heat transfer of an electrically conducting non-Newtonian Casson thin film with uniform thickness over a horizontal elastic sheet emerging from a slit in the presence of viscous dissipation. The composite effects of variable heat, mass, nanoparticle volume fraction and gyrotactic micro-organism flux are considered as is hydrodynamic (wall) slip. The Buongiorno nanoscale model is deployed which features Brownian motion and thermophoresis effects. The model studies the manufacturing fluid dynamics of smart magnetic bio-nano-polymer coatings.

Design/methodology/approach

The coupled non-linear partial differential boundary-layer equations governing the flow, heat and nano-particle and micro-organism mass transfer are reduced to a set of coupled non-dimensional equations using the appropriate transformations and then solved as an nonlinear boundary value problem with the semi-numerical Liao homotopy analysis method (HAM).Validation with a generalized differential quadrature (GDQ) numerical technique is included.

Findings

An increase in velocity slip results in a significant decrement in skin friction coefficient and Sherwood number, whereas it generates a substantial enhancement in Nusselt number and motile micro-organism number density. The computations reveal that the bioconvection Schmidt number decreases the micro-organism concentration and boundary-layer thickness which is attributable to a rise in viscous diffusion rate. Increasing bioconvection Péclet number substantially elevates the temperatures in the regime, thermal boundary layer thickness, nanoparticle concentration values and nano-particle species boundary layer thickness. The computations demonstrate the excellent versatility of HAM and GDQ in solving nonlinear multi-physical nano-bioconvection flows in thermal sciences and furthermore are relevant to application in the synthesis of smart biopolymers, microbial fuel cell coatings, etc.

Research limitations/implications

The numerical study is valid for two-dimensional, unsteady, laminar Casson film flow with nanoparticles over an elastic sheet in presence of variable heat, mass and nanoparticle volume fraction flux. The film has uniform thickness and flow is transpiring from slit which is fixed at origin.

Social implications

The study has significant applications in the manufacturing dynamics of nano-bio-polymers and the magnetic field control of materials processing systems. Furthermore, it is relevant to application in the synthesis of smart biopolymers, microbial fuel cell coatings, etc.

Originality/value

The originality of the study is to address the simultaneous effects of unsteady and variable surface fluxes on Casson nanofluid transport of gyrotactic bio-convection thin film over a stretching sheet in the presence of a transverse magnetic field. Validation of HAM with a GDQ numerical technique is included. The present numerical approaches (HAM and GDQ) offer excellent promise in simulating such multi-physical problems of interest in thermal thin film rheological fluid dynamics.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 1 August 1986

P. Evertsen

Dispersions are quite sensitive to growth and attack by micro‐organisms. This presents itself by discolouration of the dispersion, a putrid smell, gasformation and…

Abstract

Dispersions are quite sensitive to growth and attack by micro‐organisms. This presents itself by discolouration of the dispersion, a putrid smell, gasformation and alterations of the physical properties of the pH. Total disintegration such as the dispersion seldom occurs. A contaminated product does not have to show all the above mentioned effects but may show only discolouration.

Details

Pigment & Resin Technology, vol. 15 no. 8
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 February 1977

Stuart Thorne

Unless foods are treated very soon after harvest or slaughter, most will deteriorate rapidly due to the action of bacteria and other micro‐organisms. This microbial…

Abstract

Unless foods are treated very soon after harvest or slaughter, most will deteriorate rapidly due to the action of bacteria and other micro‐organisms. This microbial deterioration usually manifests itself by the typical signs of putridity, fermentation or mouldiness, but most hazardous are those bacteria that can grow to dangerous concentrations without obvious signs that they have done so. The main aim of food preservation processes is to create an environment unsuitable for microbial growth or, with processes such as canning, to destroy the micro‐organisms in the food and to pack the food so as to prevent subsequent ingress by other organisms. Micro‐organisms will not grow at very low temperatures, in low water concentrations, in high acid, salt or sugar concentrations or in the presence of certain chemicals. Thus, freezing, dehydration, pickling and salting are effective in preserving foods. Heat also destroys micro‐organisms and is used in canning and bottling and in pasteurisation, which is a partial preservation process.

Details

Nutrition & Food Science, vol. 77 no. 2
Type: Research Article
ISSN: 0034-6659

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Article
Publication date: 1 August 1962

P.W. Sherwood

Bacterial action often constitutes a major cause of corrosion in petroleum refineries and similar plant. The problem occurs in three major areas: in underground…

Abstract

Bacterial action often constitutes a major cause of corrosion in petroleum refineries and similar plant. The problem occurs in three major areas: in underground structures, in cooling water systems and in storage facilities for both crude and refined petroleum products. What are the factors upon which bacterial corrosion depends and what are the remedies?

Details

Anti-Corrosion Methods and Materials, vol. 9 no. 8
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 May 1975

A DO‐IT‐YOURSELF microbiological kit for industry, forming part of an oil and coolant care package, and which permits non‐specialist staff to quantify and classify…

Abstract

A DO‐IT‐YOURSELF microbiological kit for industry, forming part of an oil and coolant care package, and which permits non‐specialist staff to quantify and classify infections by bacteria, yeasts, fungi and sulphide generating micro‐organisms, is now being marketed by Oil Care Ltd, Racecourse Road, Pershore, Worcs. It is known as the Easicult range of products.

Details

Industrial Lubrication and Tribology, vol. 27 no. 5
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 January 1993

Geoff Waite

In the microbiology laboratories of many pharmaceutical companies, skilled scientists have been spending considerable time conducting repetitive tasks in the search for…

Abstract

In the microbiology laboratories of many pharmaceutical companies, skilled scientists have been spending considerable time conducting repetitive tasks in the search for new drugs derived from microbial natural products. In a number of these laboratories PA Consulting Group has been able to free scientists from these procedures by the application of advanced robotics to the plating out and screening of micro‐organisms.

Details

Assembly Automation, vol. 13 no. 1
Type: Research Article
ISSN: 0144-5154

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