Laser-induced damage morphology of high-reflective optical coatings

Two different kinds of 1064 nm high-reflective (HR) coatings, with and without SiO2 protective layer, were prepared by electron beam evaporation. Three-dimensional damage morphology, caused by a Nd:YAG pulsed laser, was investigated for these HR coatings. Development of laser-induced damage on HR coatings was revealed by both temperature field calculation and discrete meso-element simulation. Theoretical results met experimental very well. (C) 2004 Elsevier B.V. All rights reserved.

Impact of organic contamination on laser-induced damage threshold of high reflectance coatings in vacuum

The influence of organic contamination in vacuum on the laser-induced damage threshold (LIDT) of coatings is studied. TiO2/SiO2 dielectric mirrors with high reflection at 1064 nm are deposited by the electron beam evaporation method. The LIDTs of mirrors are measured in vacuum and atmosphere, respectively. It is found that the contamination in vacuum is easily attracted to optical surfaces because of the low pressure and becomes the source of damage. LIDTs of mirrors have a little change in vacuum compared with in atmosphere when the organic contamination is wiped off. The results indicate that organic contamination is a significant reason to decrease the LIDT. N-2 molecules in vacuum can reduce the influence of the organic contaminations and prtectect high reflectance coatings. (C) 2008 Elsevier B.V. All rights reserved.

A survey of process hygiene in the Sri Lankan prawn industry. 2. The hygiene status of personnel

Of 262 personnel tested, 137 (52%) were found to be positive for Staphylococcus aureus. Among individual companies the prevalence of S. aureus ranged from 92% (Company No. 1) to 22% (Company No. 2). Although five companies provided a sanitiser hand-dip, this was found to be ineffective for the control of S. aureus. Provision of hand-washing facilities, of protective clothing and of toilet facilities was found to be inadequate for an export food industry.

Effect of Process Conditions on Microstructure and Corrosion Resistance of Cold-Sprayed Ti Coatings

Ti and Ti alloys can be applied to steels as a protective coating in view of its excellent resistance to corrosive environment. Cold spraying, as a new coating technique, has potential advantages in fabrication of Ti coating in comparison with conventional thermal spraying techniques. In this study, Ti coatings were prepared on carbon steel substrates by cold spraying via controlling the process conditions. The microstructure of coatings was observed by SEM. The porosity of coatings was estimated by image analysis and the bond strength was tested for comparison of the process conditions. Potentiodynamic polarization and open-circuit potential (OCP) measurements were performed to understand the corrosion behavior of the coatings. The SEM examination shows that the coatings become more compact with the increases of pressure and temperature of driving gas. The potentiodynamic polarization curves indicate that the coating which has lower porosity has lower corrosion current. The polarization and OCP measurement reveal that cold-sprayed Ti coating can provide favorable protection to carbon steel substrate. The polishing treatment of coating surface polishes the rough outer layer including the small pores as well as decreases the actual surface area of the coating, leading to the considerable improvement of corrosion resistance.

Corrosion resistance of steel with hot-dipped galvanized zinc and zinc alloy coatings in seawater

Hot-dipped galvanized zinc and zinc alloy coatings were used as the hot-dipped low alloy zinc coatings (aluminum content less than protective metallic coatings for steel structures in seawater in Chi- or equal to 10 wt%) is equal to or even lower than that of the pure na. Corrosion of the two coatings immersed in sea water in Qingdao zinc sheet, while the performance of the hot-dipped high alloy zinc and Xiamen for 6 years were introduced and analyzed, which pro-coatings is higher than that of the pure zinc sheet. The hot-dipped vides a basis for further development and applications of these coat- high alloy zinc coatings can be further developed for optimal tings in China. Tests proved that the anti-corrosion performance of formance in the future.

Satellite monitoring of harmful algal blooms (HABs) to protect the aquaculture industry

Harmful algal blooms (HABs) can cause sudden and considerable losses to fish farms, for example 500,000 salmon during one bloom in Shetland, and also present a threat to human health. Early warning allows the industry to take protective measures. PML's satellite monitoring of HABs is now funded by the Scottish aquaculture industry. The service involves processing EO ocean colour data from NASA and ESA in near-real time, and applying novel techniques for discriminating certain harmful blooms from harmless algae. Within the AQUA-USERS project we are extending this capability to further HAB species within several European countries.

Assessing the occupational risk of dust particles in the Kenyan tanning industry using rapid image processing and microscopy techniques

The purpose of this study was to investigate the occupational hazards within the tanning industry caused by contaminated dust. A qualitative assessment of the risk of human exposure to dust was made throughout a commercial Kenyan tannery. Using this information, high-risk points in the processing line were identified and dust sampling regimes developed. An optical set-up using microscopy and digital imaging techniques was used to determine dust particle numbers and size distributions. The results showed that chemical handling was the most hazardous (12 mg m(-3)). A Monte Carlo method was used to estimate the concentration of the dust in the air throughout the tannery during an 8 h working day. This showed that the high-risk area of the tannery was associated with mean concentrations of dust greater than the UK Statutory Instrument 2002 No. 2677. stipulated limits (exceeding 10 mg m(-3) (Inhalable dust limits) and 4 mg m(-3) (Respirable dust limits). This therefore has implications in terms of provision of personal protective equipment (PPE) to the tannery workers for the mitigation of occupational risk.

Application of fibre assemblies as damping elements in the automotive industry

This investigation aims to characterise the damping properties of the nonwoven materials with potential applications in automotive and aerospace industry. Nonwovens are a popular choice for many applications due to their relatively low manufacturing cost and unique properties. It is known that nonwovens are efficient energy dispersers for certain applications such as acoustic damping and ballistic impact. It is anticipated that these energy absorption properties could eventually be used to provide damping for mechanical vibrations. However the behaviour of nonwovens under dynamic load and vibration has not been investigated before. Therefore we intend to highlight these aspects of the behaviour of the nonwovens through this research. In order to obtain an insight to the energy absorption properties of the nonwoven fabrics, a range of tests has been performed. Forced vibration of the cantilever beam is used to explore damping over a range of resonance modes and input amplitudes. The tests are conducted on aramid, glass fibre and polyester fabrics with a range of area densities and various coatings. The tests clarified the general dynamic behaviour of the fabrics tested and the possible response in more real application condition as well. The energy absorption in both thickness and plane of the fabric is tested. The effects of the area density on the results are identified. The main absorption mechanism is known to be the friction. The frictional properties are improved by using a smaller fibre denier and increasing fibre length, this is a result of increasing contact surface between fibres. It is expected the increased friction result in improving damping. The results indicate different mechanism of damping for fiber glass fabrics compared to the aramid fabrics. The frequency of maximum efficiency of damping is identified for the fabrics tested. These can be used to recommend potential applications.

The protective and attractive covering of a vegetated embankment using coir geotextiles

This paper presents the results of a field experiment conducted in Kerala, South India, to test the effectiveness of coir geotextiles for embankment protection. The results reveal that treatment with geotextile in combination with grass is an effective eco-hydrological measure to protect steep slopes from erosion. In the context of sustainable watershed management, coir is a cheap and locally available material that can be used to strengthen traditional earthen bunds or protect the banks of village ponds from erosion. Particularly in developing countries, where coir is abundantly available and textiles can be produced by small-scale industry, this is an attractive alternative for conventional methods. This paper analyses the performance of coir geotextile in different treatments with respect to soil moisture content, protection against erosion and biomass production

Marine yeast Candida MCCF 101 as feed supplement in aquaculture: nutritional quality, optimization of large scale production and evaluation of its protective effect on Koi carp from Aeromonas infection

Marine yeast have been regarded as safe and showing a beneficial impact on biotechnological process. It provides better nutritional and dietary values indicating their potential application as feed supplements in aquaculture. Brown et al. (1996) evaluated all the marine yeasts characterised with high protein content, carbohydrate, good amino acid composition and high levels of saturated fats. However, there is paucity of information on marine yeasts as feed supplements and no feed formulation has been found either in literature or in market supplemented with them. This statement supported by Zhenming et al. (2006) reported still a lack of feed composed of single cell protein (SCP) from marine yeasts with high content of protein and other nutrients. Recent research has shown that marine yeasts also have highly potential uses in food, feed, medical and biofuel industries as well as marine biotechnology (Chi et al., 2009; 2010). Sajeevan et al. (2006; 2009a) and Sarlin and Philip (2011) demonstrates that the marine yeasts Candida sake served as a high quality, inexpensive nutrient source and it had proven immunostimulatory properties for cultured shrimps. This strain has been made part of the culture collection of National Centre for Aquatic Animal Health, Cochin University of Science and Technology as Candida MCCF 101. Over the years marine yeasts have been gaining increased attention in animal feed industry due to their nutritional value and immune boosting property.Therefore, the present study was undertaken, and focused on the nutritional quality, optimization of large scale production and evaluation of its protective effect on Koi carp from Aeromonas infection

Rational engineering of recombinant picornavirus capsids to produce safe, protective vaccine antigen

Foot-and-mouth disease remains a major plague of livestock and outbreaks are often economically catastrophic. Current inactivated virus vaccines require expensive high containment facilities for their production and maintenance of a cold-chain for their activity. We have addressed both of these major drawbacks. Firstly we have developed methods to efficiently express recombinant empty capsids. Expression constructs aimed at lowering the levels and activity of the viral protease required for the cleavage of the capsid protein precursor were used; this enabled the synthesis of empty A-serotype capsids in eukaryotic cells at levels potentially attractive to industry using both vaccinia virus and baculovirus driven expression. Secondly we have enhanced capsid stability by incorporating a rationally designed mutation, and shown by X-ray crystallography that stabilised and wild-type empty capsids have essentially the same structure as intact virus. Cattle vaccinated with recombinant capsids showed sustained virus neutralisation titres and protection from challenge 34 weeks after immunization. This approach to vaccine antigen production has several potential advantages over current technologies by reducing production costs, eliminating the risk of infectivity and enhancing the temperature stability of the product. Similar strategies that will optimize host cell viability during expression of a foreign toxic gene and/or improve capsid stability could allow the production of safe vaccines for other pathogenic picornaviruses of humans and animals.

Anticorrosive cerium-based coatings prepared by the sol-gel method

The development of efficient anti-corrosion and environmentally friendly coating systems are needed for the replacement of the highly toxic Cr-based conversion coatings for corrosion protection of aluminum alloys. In this study, we demonstrate that the direct application of ceramic cerium-based sol-gel coatings to AA7075-T6 substrates produces high-performance anti-corrosion layers. Electrochemical experiments and analyses of the microstructure demonstrate that the protective layers are very efficient for the passivation of the alloy surfaces operating as both passive and active barrier for corrosion protection.

An investigation of tribological properties of CN and TiCN coatings

Today the tool industry on a worldwide basis uses hard, wear-resistant, and low-friction coatings produced by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, chemical-vapor deposition (CVD), and physical vapor deposition (PVD). In the current work, two different coatings, nitrocarburized (CN) and titanium carbonitride (TiCN) on M2-grade tool steel, were prepared by commercial diffusion and PVD techniques, respectively. Properties such as thickness, roughness, and hardness were characterized using a variety of techniques, including glow-discharge optical emission spectrometry (GD-OES) and scanning electron microscopy (SEM). A crossed-cylinders wear-testing machine was used to investigate the performances of both coatings under lubrication. The effect of coatings on the performance of lubricants under a range of wear-test conditions was also examined. Degradation of lubricants during tribological testing was explored by Fourier transform infrared (FTIR) spectroscopy.