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Article
Publication date: 1 April 1996

S. Hamilton

With the increasing trends towards fineline circuitry,contamination has become a major cause of defects. This paper outlines the techniques used inconducting a…

Abstract

With the increasing trends towards fineline circuitry, contamination has become a major cause of defects. This paper outlines the techniques used in conducting a Contamination Audit and in generating a Contamination Matrix, which is a map of the types of contamination and their relative levels within a facility. Using the Contamination Matrix contamination control measures can be targetted in the most effective manner to achieve yield improvements.

Details

Circuit World, vol. 22 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 December 1996

S. Hamilton

With the increasing trends towards fineline circuitry,contamination has become a major cause of defects. This paper outlines the techniques used inconducting a…

Abstract

With the increasing trends towards fineline circuitry, contamination has become a major cause of defects. This paper outlines the techniques used in conducting a Contamination Audit and in generating a Contamination Matrix, which is a map of the types of contamination and their relative levels within a facility. Using the Contamination Matrix contamination control measures can be targetted in the most effective manner to achieve yield improvements.

Details

Circuit World, vol. 22 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 8 February 2016

Guangying Ma, Shurong Ning, Yunlong Hu and jun Gao

The aim of this study is to establish a dynamic model of the filtration ratio. For the problem that the measured value of the filtration ratio is far less than the…

Abstract

Purpose

The aim of this study is to establish a dynamic model of the filtration ratio. For the problem that the measured value of the filtration ratio is far less than the theoretical value in the actual hydraulic filtering system, the paper aims to find the relationship between the filtration ratio and the parameters of the hydraulic systems, such as the contamination level and the dirt-holding quantity of the filter.

Design/methodology/approach

The paper opted for the method of experimental analysis and simulation to determine the relationship between the filtration ratio and the parameters of the hydraulic system, and established a dynamic filtration ratio model.

Findings

The paper provides a preliminary model of dynamic filtration ratio, and the model shows that the filtration ratio is exponentially related to the contamination level and the dirt-holding quantity. Different filters have different influence coefficients. The filtering capacity for a certain particle size and the contamination level control of the filter for different hydraulic systems can be judged according to the dynamic balance equation of hydraulic systems.

Originality/value

The paper is useful in the selection of filters and in the precise control of the contamination level of the hydraulic system.

Details

Industrial Lubrication and Tribology, vol. 68 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 8 April 2021

Karla M. Acosta, Zahra H. Mohammad, Heyao Yu, Kristen Kirkwood, Kristen Gibson, Jack A. Neal and Sujata A. Sirsat

The purpose of this study was to investigate whether the layout has an effect on cross-contaminations levels at farmers markets.

Abstract

Purpose

The purpose of this study was to investigate whether the layout has an effect on cross-contaminations levels at farmers markets.

Design/methodology/approach

We used social cognitive theory's triadic reciprocity model to investigate how influencing the environment could change the behaviors of farmers’ market consumers and reduce the risk of microbial cross-contamination using a Fluorescent Compound (FC). For this purpose, a 3 × 2 experimental between-subject factorial design was utilized in this study: three farmers market layouts (i.e. U-shaped [U-S], L-shaped [L-S] and square-shaped [S–S]) and two different set-ups per market (i.e. produce and non-produce vendors completely separated, and alternating produce and non-produce vendors). FC was utilized to simulate microbial contamination on the participants (n = 54) hands. The participants were allowed to walk through the layout for 3 min and touch items after which a total of 475 swab samples were processed and recorded for absorbance levels.

Findings

The results indicated that the cross-contamination level of the U-S market was significantly lower (p < 0.001) than those of the L-S and S–S markets. The best market layout and set-up based on the average levels of simulated cross-contamination were the U-S market, particularly with the A set-up, where produce and non-produce booths were scattered.

Originality/value

This study is the first to use the quantification of FC to identify the impact of a farmers’ market layout/design on cross-contamination levels. These results can be used to provide guidance to market managers on layout and design from a safety standpoint to reduce the risk of cross-contamination.

Details

British Food Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 4 August 2020

Naeun Lauren Kim and Byoungho Ellie Jin

One of the major concerns in the emerging phenomenon of collaborative consumption (CC) is the issue of contamination (i.e. feeling “grossed out” when sharing items with…

Abstract

Purpose

One of the major concerns in the emerging phenomenon of collaborative consumption (CC) is the issue of contamination (i.e. feeling “grossed out” when sharing items with others). Guided by the law of contagion and the consumer contamination effect theory, this research investigated the ways in which companies can manipulate in order to reduce the negative contamination when renting or purchasing used fashion items from others. Specifically, this research examines this issue of contamination through the ownership type of the shared goods (e.g. corporate-ownership or B2C exchange, and consumer-ownership or C2C exchange) and its effect on consumers' CC intentions in two distinct sharing contexts (i.e. rental and secondhand purchase).

Design/methodology/approach

A total of 181 American female consumers were assigned to an experimental CC scenario, and their rental/secondhand purchase intentions were compared through ANCOVA analysis.

Findings

In both rental and secondhand purchase contexts, consumers displayed greater intentions to shop in B2C setting (i.e. corporate-ownership) with no direct contact with the previous owner, than in C2C setting (i.e. consumer-ownership) with a greater association with the previous owner and the shared items. Such inclination was more prevalent when purchasing a shirt than a handbag, suggesting that consumers feel more grossed out when there is greater physical contact with the shared item.

Originality/value

The findings of the study suggest a possible solution to alleviate the contamination effect, and the discovery of the degree of contact as a moderator provides new insight into contamination research.

Details

Journal of Fashion Marketing and Management: An International Journal, vol. 25 no. 2
Type: Research Article
ISSN: 1361-2026

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Article
Publication date: 1 April 2020

Simon Hazée and Yves Van Vaerenbergh

Customers might become concerned about getting contaminated and adapt their behavior accordingly, which is of critical concern for service managers. The purpose of this…

Abstract

Purpose

Customers might become concerned about getting contaminated and adapt their behavior accordingly, which is of critical concern for service managers. The purpose of this paper is threefold. First, this paper synthesizes the extant body of research within psychology and marketing into an integrative framework that helps understand the current state of knowledge on contamination. Second, this review summarizes evidence-based managerial recommendations on how to deal with customers' contamination concerns. Third, this paper provides guidance for future research by proposing several ways in which those concerns might influence service management.

Design/methodology/approach

This paper conducts an integrative literature review of over 30 years of psychology and marketing research on contamination concerns.

Findings

The paper reviews physical and metaphysical contagion models, the situational cues that may activate customers' contamination concerns, the psychological mechanisms that underlie the relationship between contamination and customer outcomes and the individual characteristics that influence customer sensitivity to contamination cues. Moreover, this review identifies actions that service managers can take to prevent customers' contamination concerns. Finally, still much has to be learned about how organizations should deal with fear of contamination by the time a next pandemic breaks out.

Originality/value

This paper develops an integrative framework that serves as a structured knowledge map onto the contamination phenomenon and paves the way for future service research.

Details

Journal of Service Management, vol. 32 no. 2
Type: Research Article
ISSN: 1757-5818

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Article
Publication date: 25 February 2020

Abayomi Isaac Adeleke, Bamidele Sunday Fakinle, Olayemi Abosede Odunlami and Jacob Ademola Sonibare

The study investigated the heavy metal flux around the vicinity of a steel recycling factory using passive biomonitoring technique with several pollution indices to assess…

Abstract

Purpose

The study investigated the heavy metal flux around the vicinity of a steel recycling factory using passive biomonitoring technique with several pollution indices to assess the quality of the ambient environment.

Design/methodology/approach

The vegetation around the facility was identified, and the most abundant species were selected for analysis. The collected samples were dried, milled, sieved and analyzed for elemental composition using energy dispersive X-ray fluorescence (ED-XRF). Pollution indices were used to quantitatively assess the data.

Findings

Results show that maximum contamination occurs at the vicinity of factory. Generally, the deterioration of the ambient air around the vicinity of the steel recycling plant decreases with increasing distance from the steel recycling plant. However, for the radius considered in this study – 1 km, the ambient air at 1 km of the steel recycling facility is quickly deteriorating, and there is an urgent need for measures to mitigate the air quality impact of the steel recycling facility.

Originality/value

The study shows that the metal recycling process emits high levels of heavy metals to the environment, and there is an urgent need for personal protective equipment for the human population working in and around the close proximity of the recycling plant.

Details

Management of Environmental Quality: An International Journal, vol. 31 no. 3
Type: Research Article
ISSN: 1477-7835

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Article
Publication date: 27 September 2011

Sven Berg, Ulf Jungmar, Jan Lundberg and Pekka Vähäoja

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully…

Abstract

Purpose

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully formulated hydraulic and gear oils taken from working systems.

Design/methodology/approach

In this investigation, two different spectrometric techniques, inductively coupled plasma‐optical emission spectrometers (ICP‐OES) and rotating disk electrode‐optical emission spectrometers (RDE‐OES), have been studied to determine the instruments' precision of measurement and ability to measure the absolute level of contamination. The study was based on a series of measurements using artificial contamination mixed with oil.

Findings

The ICP has better precision of measurement of the two instruments, but cannot predict the absolute values of contamination when oil samples are only treated by organic solvent dilution if the samples include large or dense particles. It is therefore not too good, with the sample pre‐treatment method used, at detecting wear processes that produce dense/large particles, such as pitting failure. For instance, microwave‐assisted acid digestion could be used for sample pre‐treating to obtain accurate results in that case. It should, however, be able to detect wear mechanisms that produce small particles such as abrasive wear in any case. The ICP has a repeatability value of r=3 percent and a reproducibility value of R=12 percent for contamination levels of between 50 and 400 ppm and r=0.6  and R=2 ppm, respectively, at values below 50 ppm. The RDE cannot predict the absolute value of contamination if this includes large or dense particles if proper sample pre‐treatment is not used. It is therefore not good at detecting wear mechanisms that produces dense/large particles (if the oil samples are not pre‐treated properly) such as pitting but should be able to detect abrasive wear and similar processes that produce small particles in any case. The RDE's precision of measurement is not as good as the ICP, with a reproducibility variation of R=r=25 percent for contamination levels between 20 and 500 ppm and R=r=6 ppm for contamination level below 20 ppm.

Research limitations/implications

Only the effects from lubricating oils are studied.

Practical implications

This study will significantly increase the industrial knowledge concerning measurement precision in particle contamination measurement systems.

Originality/value

No similar study is found.

Details

Industrial Lubrication and Tribology, vol. 63 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 7 March 2016

Frazer Howard Smith

During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide…

Abstract

Purpose

During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide range of field joint coating (FJC) types is available for coating this bare section, functioning in conjunction with the pipeline cathodic protection system to provide an anti-corrosion system or package. This paper aims to relate to two-layer type heat shrink sleeves (2LHSS), which commonly are used for FJC of concrete-weighted offshore pipelines where the sleeve typically is over-coated with a solid or foam type polyurethane “infill”. Similar sleeves also are used sometimes in exposed conditions on lines without concrete over-coating. The maximum allowable soluble salt contamination prior to application of high-performance coating systems can vary, depending upon the coating type, but typically has been set at 20 mg/m2 (de la Fuente et al., 2006). The first layer of three-layer heat shrink sleeve (3LHSS) systems for pipeline FJC, liquid epoxy, falls into this category (ISO_21809-3:2008, 2008). In contrast, the 2LHSS system does not use a liquid epoxy first layer but relies instead on the bonding of a “mastic” layer directly to the pipe metal surface. The maximum acceptable concentration of salt contamination on prepared metal surfaces prior to the application of 2LHSS has been a subject of debate and was the focus of this study. International standards for FJC do not provide a maximum salt level. However, some companies have continued to specify low thresholds for the maximum allowable salt level for 2LHSS, which can result in expensive delays in production during offshore pipe-lay. In this study, salt contamination levels of up to 120 mg/m2 were found to have no effect on peeling performance after accelerated aging by hot water immersion. Furthermore, preparation for welding and the use of potable water during ultrasonic testing procedures prior to FJC, typically reduces the salt contamination level to below 50 mg/m2 providing a strong case for the deletion of salt contamination testing for 2LHSS.

Design/methodology/approach

The potential risk of failure of the coating due to poor surface cleanliness/contamination was assessed by testing the adhesion between the coating and the steel substrate to which the coating is adhering, following a period of hot water immersion. Compliance with ISO 21809-3 “Annex I” requires 28 days’ immersion at maximum operating temperature. For this study, to create a severe situation, the test rings were subjected to accelerated aging by water immersion at the HSS upper specified temperature of 65°C for more than twice the specified period (ISO_21809-3:2008, 2008). Two HSS were tested; one was widely used in applications where exposure to moderate mechanical stress is required, having a high shear strength type mastic “hybrid” adhesive containing a significant proportion of amorphous polypropylene blended with tackifiers and ethylene vinyl acetate (EVA), Andrenacci et al. (2009) referred to as “Type A”. The second, referred to as “Type B”, is widely used in applications where it is covered by a layer of “infill”, typically consisting of polyurethane foam or solid polyurethane elastomer, i.e. typical design methodology for concrete coated pipelines. “Type B” HSS had a more moderate strength traditional type mastic than “Type A” containing a significant percentage of butyl rubber with asphalt, activation agents and tackifying resins. To determine how to apply the salt contamination without causing flash rust, a mini-study was completed on the steel substrate. After numerous trials, it was found impossible to not to form visible rust on the pipe surface. The extent of rusting was minimised by heating the pipe immediately after the application of the salt solution.

Findings

High levels of sea salt on power tool prepared pipe surfaces were investigated by peel testing of 2LHSS after hot water immersion and compared against peel tests undertaken prior to hot water immersion. The test conditions were considered severe: salt contamination levels of up to 120 mg/m2 applied on power tool cleaned pipe surfaces that had been aged for one year without prior grit blasting. The accelerated ageing procedure had twice the specified (ISO_21809-3:2008, 2008) water immersion duration, and the test samples had exposed edges providing the possibility for moisture to creep under the coating. The test results showed that there were no noticeable deleterious effects on the performance of the two most commonly used FJCs, 2LHSS. Therefore, it was concluded that, as the level of salt contamination on prepared pipe surfaces after wet non-destructive testing typically is much lower than the levels tested in this study, pipe surfaces prepared for the application of 2LHSS type do not require specific additional measures to further reduce salt contamination, provided that care is taken to ensure that these conditions are maintained consistently during pipe laying operations.

Practical implications

The frequency of salt contamination testing of power tool cleaned surfaces prior to mastic type heat shrink sleeves can be minimised, and perhaps omitted entirely, provided the above criteria are satisfied.

Originality/value

A literature review revealed there was little published information on the testing of 2LHSS and nothing related to hot water immersion testing. Hence, the results of this investigation have provided useful industrial data regarding the effect of hot water ageing and the influence of surface salt contamination on field joint corrosion prevention capabilities.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 1 July 2005

I.W. Haysom and A.K. Sharp

Many cases of food poisoning originate in the domestic environment and can be associated with improper food handling and ineffective cleaning by consumers. These practices…

Abstract

Purpose

Many cases of food poisoning originate in the domestic environment and can be associated with improper food handling and ineffective cleaning by consumers. These practices could lead to the introduction and spread of bacterial contamination in the kitchen and if not subsequently removed could present an infection risk. This study proposes investigating changes in levels of bacterial contamination at five key sites in ten domestic kitchens during a period of 24 hours.

Design/methodology/approach

Microbiological swabs were used to provide an aerobic colony count and an Enterobacteriacea count. A record was kept of cooking, cleaning and other activities within the kitchen.

Findings

Results showed that contamination levels varied during the day, peaking after meal preparation and generally falling overnight. There was also indirect evidence of cross contamination, particularly from hands to other surfaces. Sites such as the refrigerator handle, kettle handle and taps, which generally only come into contact with hands, show increases in the levels of contamination recorded. Levels of microbiological contamination were lower in vegetarian than non‐vegetarian households. A variety of data showed that non‐food preparation activities also take place in the kitchen. These could also introduce bacterial contamination into the kitchen and facilitate their spread.

Originality/value

The implications of these results are that the most important time for cleaning in the kitchen is immediately after food has been prepared, with attention focussing on high risk areas such as the work surface, chopping board, taps and other hand contact surfaces.

Details

British Food Journal, vol. 107 no. 7
Type: Research Article
ISSN: 0007-070X

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