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This paper aims to discuss about the benefits of Cu(NO₃)₂ applied in coating paint film that consists of plant extract from Cassia Alata. Cu(NO₃)₂ has been added to the coating paint film as a colour stabilizer and as an antifungal property by forming a zone of inhibition towards fungal growth.

The coating paint film resin consists of a mixture of poly (methyl methacrylate) (PMMA) and acrylic polyol. The coating paint film’s performances were observed in terms of visible optical and physical appearance.

When exposed to the fungus Trichoderma Sp., a zone of inhibition of 208 mm² was formed around the coating paint film and therefore it gave the coating paint films an antifungal property. The commission internationale de l’éclairage (CIE) L*a*b* colour coordinate system was used to identify the colour changes in the coating paint film and it was found that the addition of Cu(NO₃)₂ to the coating paint film has a better colour stability, as it has a lower standard deviation (STD) value of 6.46 than the pure dye coating paint film of 8.95. The gloss of coating paint film with the addition of Cu(NO₃)₂ was found to be have a more stable gloss based on its smaller STD value at both angles taken at 20° and 60°.

The Cassia Alata plant has different amount of antifungal properties based on location its growth.

The coating paint film developed in this study is suitable for indoor applications.

The plant extract from the Cassia Alata gives the coating paint film an antifungal property.

This paper aims to study the colour stability of chlorophyll and the effect of copper (II) nitrate – Cu(NO₃)₂ – as an additive in natural dye coating films after being exposed to ultraviolet-A (UV-A).

The natural dye was extracted from the leaves of Cassia alata L. using absolute ethanol as the solvent. The extract was divided into two parts and, one of it was added with 3 wt.% Cu(NO₃)₂ as an additive. The polymer blend of poly(methyl methacrylate) (PMMA) and acrylic polyol was used as the coating binder. Both parts of the dye with and without additive were mixed with the blended polymer in a specific ratio. The resulted mixtures were applied as coating films on glass substrates. The colour stability of the coating films on exposure to UV-A with the time of exposure was observed with Commission internationale de l’éclairage (CIE) L*a*b* colour coordinates. The hidden power by the means of reflectivity and glossiness of the coatings was also studied. Statistical standard deviation (STD) was used to analyse the data.

The test showed that the coating films containing Cu(NO₃)₂ had smaller colour differences, (ΔE*) indicating higher colour stability. The analysis on hidden power also showed that the coating film with Cu(NO₃)₂ was 1.6 times more stable than the film without additive. All the measurements in this study were observed within 35 days of duration.

This paper implies the potential of using natural dye extracted from Cassia alata L. leaves as a stable dye colourant for coating applications.

The coating film developed in this study is suitable for glass substrate applications.

A new method of preparing solvent-based coating film from PMMA–acrylic polyol with chlorophyll colourant is introduced in this study.

The purpose of this paper is to study the colour stability and water content resistivity of the green colour coating paint film (consisting of chlorophyll) during exposure to ultraviolet A (UV-A).

The natural green dye was prepared by immersing Cassia alata L. leaves in absolute ethanol. The extract was prepared in two batches of dye samples where one of it was a pure dye and the other was added with 3 Wt. % Cu(NO₃)₂ as an additive. Polymer blend as a binder was prepared by mixing poly(methyl methacrylate) (PMMA) and commercial acrylic polyol. The blended polymer was mixed with the natural dye in a specific ratio and applied as coating paint film on glass panel surfaces. The visible spectrum stability (colour stability) and water content resistivity of the coating paint films during exposure to UV-A were monitored.

Addition of Cu(NO₃)₂ had improved the colour stability of the coating paint film. Fourier transform infrared spectroscopy analysis showed that both coating paint films do not absorb water and are resistive to water content.

The ability of Cu(NO₃)₂ as an colour stability additive to the natural green dye applied in the coating paint film.

The coating paint film developed in this work is suitable to be applied on glass substrates.

The colour stability of the coating paint film was analysed by using the reflectance spectrum.

The purpose of this paper is to propose a new method of synthesis of CuO · SiO₂ oxide composite based on the reaction of precipitation from water solutions of sodium silicate and copper nitrate.

Solutions of sodium silicate and copper nitrate were used as substrates. The effects of direction of substrate supply, concentration, excess of reagents and temperature of precipitation on the physicochemical properties of the products were analysed.

A new method of synthesis of CuO · SiO₂ oxide composite based on a precipitation reaction is proposed.

Only sodium silicate and copper nitrate solutions were used.

The CuO · SiO₂ oxide composite obtained can be used as blue pigment or polymer filler.

The paper determines optimum conditions of CuO · SiO₂ oxide composite precipitation to obtain products with desired physicochemical, dispersive and structural properties.

Waste Heat Recovery Boilers (WHRB's) enhance the thermal efficiency of gas turbine power generating plants by capturing the heat from the exhaust gas and utilising it to raise steam for increased electricity production or district heating. Under normal conditions the exhaust gas from the turbine is cooled from around 550°C to 80°C. Care is taken that condensation will not occur in the cooler parts of the boiler. Nevertheless, during normal operation, dry ammonium nitrate deposits can be formed in the WHRB. These deposits will become wet when the unit is started or shut down, when the temperature falls below the dew point. The deposits may also “sweat” (i.e. absorb atmospheric moisture and become liquid) during extended plant outage periods. In consequence, Intergranular Corrosion Attack (IGA) and Stress Assisted Intergranular Corrosion Attack (SA‐IGA) (in general called stress corrosion cracking) can occur in carbon steel construction materials. The sensitivity to IGA of a total of 86 steels, of known compositions, was tested. The steels were subjected to aerated ammonium nitrate solutions of 90°C with concentrations ranging between 2 and 35 per cent. After an exposure of 65 hours, cross sections of the steels were studied. If IGA occurred, the steel was considered sensitive to ammonium nitrate at that (critical) percentage. During the investigation it was observed that alloying elements in several types of steel influenced its resistance to IGA in ammonium nitrate. Elements such as molybdenum, manganese and chromium had a positive effect on the resistance to nitrate induced IGA, SA‐IGA and stress corrosion cracking, whereas carbon and copper were detrimental. The microstructure of the steel also appeared to be important. In many specimens taken from in‐service failures, strings of carbide precipitates were found to be present at grain boundaries. The precipitates were identified to be ternary carbides. It seems, therefore, that the presence of carbides at grain boundaries increases the susceptibility of a steel to intergranular corrosion.

A corrosion inhibitor may be defined as a material which, when added in small amounts to a corrosive product or environment affecting a metal, effectively decreases its corrosion rate or perhaps prevents it altogether.

This article aims to review the different devices that are available for the in situ monitoring of analytes found in the marine environment.

Following a short introduction to the topic, this paper discusses physical‐ and chemical‐based sensors, automatic analysers (flow injection, spectroscopic and spectrometric), electrochemical devices and biosensors.

A wide range of in situ monitoring systems (and associated deployment apparatus) for measuring concentrations of various analytes (e.g. nutrients, organic chemicals and metallic elements) have been developed in recent decades. Many of these systems are still at the laboratory or prototype stage and are yet to be fully developed into commercially available products. The harsh conditions often found in the marine environment can further limit the utility and application of these sensors. Further development work is needed; however, the need now is for field deployments, validation and inter‐calibration between sensors and other analytical measurement techniques.

This paper provides up‐to‐date information on in situ technologies that are available, either at the laboratory and prototype stages or commercially, and are suitable for deployment in the marine environment. Applications of these sensing systems are discussed together with their associated advantages and disadvantages over other existing water monitoring methods.

The purpose of this paper is to investigate the effect of chloride along with NO₂ on the atmospheric corrosion of bronze using exposure tests.

Surface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.

The results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO₂ is observed clearly, though no nitrate existed in the corrosion products.

A new catalyst theory has been suggested in this paper, i.e. that NO₂ acts as a catalyst during the corrosion process when significant quantities of chloride also are present.

The statements which have recently been made in various quarters to the effect that Danish butter is losing its hold on the English market, that its quality is deteriorating, and that the sale is falling off, are not a little astonishing in face of the very strong and direct evidence to the contrary furnished by the official records. As an example of the kind of assertions here alluded to may be instanced an opinion expressed by a correspondent of the British Food Journal, who, in a letter printed in the March number, stated that “My own opinion is that the Danes are steadily losing their good name for quality, owing to not using preservatives and to their new fad of pasteurising… .”

The purpose of this paper is to obtain knowledge about one of the issues that affects the ecosystem in Guanabara Bay, Rio de Janeiro State, Brazil. Studies on the environment are of fundamental importance if the quality of life of the inhabitants of certain regions is to be assured.

Physicochemical and biological analysis were performed of samples collected at four points along the river. Some of the parameters established by CONAMA Brazilian Regulation #357/05 were evaluated.

This paper did a physicochemical and biological characterization of a significant tributary river to the Guanabara Bay. This level of characterization has not been done before. The results achieved show that this river was in a worse condition than what was expected.

With its potential for tourism and fishing, and its importance to Rio de Janeiro City and the State as a whole, Guanabara Bay should be the object of more in‐depth studies and actions of a practical nature to bring about its ecological recovery.

This paper is a new source of information about this important tributary, as is Faria‐Timbó River to Guanabara Bay. This bay borders on a number of municipalities in the State and is of crucial importance not just for the neighboring towns and cities, but also for the entire State because of the fish stocks it harbors, which are consumed in the region.