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The aim of this work was to investigate which parameters affect the long‐term performance of coil coated galvanised steel sheet. Therefore, the paint adhesion and corrosion resistance of selected painted pre‐treated galvanised steel substrates were studied. The systems investigated included chromate‐free pre‐treatments and primers. The polymer coated panels were tested by using: T‐bend, combined cross cut and adhesion, prohesion and QUV‐A tests. The surface energy of the painted panels was determined by contact angle measurements and outdoor testing of the panels was also initiated. The test results showed that the primer was the most important parameter for painted metal alloy coated steel, but the long‐term performance of the system also depends on the compatibility of all four layers, i.e. substrate, pre‐treatment, primer and topcoat.

Modern applications for coil‐coated metal have resulted in increased demand from the paint supplier to produce products with enhanced performance compared to conventional coating counterparts. Today, coaters and their end‐users are no longer satisfied with products which merely meet specifications, but are looking for enhanced corrosion resistance, flexibility, hardness and chemical resistance along with the requirement to achieve finishes previously not associated with the coil coating process.

This study aims to examine the effects of various physical and chemical pre-treatments on antioxidant properties of tree bean (Parkia roxburghii G. Don) in combination with storage conditions.

The whole pods and seeds of tree bean were treated with gamma rays (γ-rays), sodium hypochlorite (NaOCl), chlorine dioxide (ClO₂) and hydrogen peroxide (H₂O₂) and stored at room temperature (RT, 25°C) for 30 days. The physical and chemical pre-treated seeds and pods were compared with the same stored at RT and refrigerated storage at 4°C and −20°C. During storage, physical (moisture content) and antioxidants like total phenolics, ascorbate content, reduced glutathione, total flavonoids, along with free radical scavenging activities (FRSA) were measured.

Chemical pre-treatments with NaOCl, ClO₂ and H₂O₂ significantly accelerated (p = 0.05) the total phenolics (1.9 mg/g FW in seeds and 2.4 mg/g FW in pods), flavonoids content (0.3 mg/g FW each in seeds and pods) and ABTS activities (73.3 per cent in seeds and 92.3 per cent in pods) at 30 days of storage. A significant decrease (p = 0.05) in ascorbate content (6.1 mg/g FW in seeds and 3.5 mg/g FW in pods), reduced glutathione (5.1 mg/g FW in seeds and 3.7 mg/g FW in pods), FRAP (0.3 mg equi Fe/g FW in seeds and 0.4 mg equi Fe/g FW in pods) and reducing power (1.8 mg/g FW in seeds and 3.7 mg/g FW in pods) was observed under all the treatments at 30 days of storage. However, DPPH increased under γ-irradiation and decreased under chemical pre-treatments, storage at RT and refrigerated storage. The overall result showed that pre-treatment of H₂O₂ at 10-20 mM maintains antioxidants and radical scavenging activities in tree bean during storage.

The application of H₂O₂ at 10-20 mM prior to storage of tree bean maintains the physical, antioxidant properties and FRSA in tree bean seeds and pods as compared to natural ambient conditions. Hence, this technique will help in improving the keeping quality of this legume and avoid spoilage after harvest for an extended period.

Low-temperature plasma (LTP) has been increasingly employed for polymer surface modifications. In this paper, plasma gases of oxygen and argon were used for pre-treating polyester fabrics before conducting chemical silver plating, aiming to increase the amount of metal content and improve the performance of the polyester fabrics. After LTP pre-treatment, there was a thin plasma layer generation on the fabric surface which was in good contact with the fibre. Based on the observation of micro-structure using scanning electron microscopy (SEM), it was found that there was an increase in the amount of silver particles deposited on the fibre surface after the LTP pre-treatment. The surface observation implies that the LTP pre-treatment could enhance the hydrophilicity of fibre surface and help facilitate the absorption of silver particle layer to reach the necessary level of uniformity and adhesive strength.

Chemical treatability of dairy wastewater originating from a dairy and dairy products plant at Istanbul was investigated on the basis of chemical oxygen demand (COD) parameter as a pre‐treatment alternative. FeCl₃, FeSO₄ and alum were used as coagulants in the jar‐test experiments of four sets of daily composite wastewater samples taken once every month. The effect of acid cracking has also been searched through acid addition and pH adjustment. Characterisation studies demonstrated that wastewater characteristics varied within a wide range in spite of no significant production changes at the plant during the experimentation period. Optimum coagulant dosage has been determined as 200mg l^–1 for all the coagulants with the optimum pH values between 4 and 4.5 for FeCl₃ and FeSO₄, and 5‐6 for alum. Maximum overall COD removal efficiencies were obtained as 72 per cent, 59 per cent and 54 per cent for FeCl₃, FeSO₄ and alum, respectively. Nevertheless, COD removal efficiencies were found to be inadequate to meet the current discharge standards of Greater Metropolitan Istanbul to sewer systems indicating that chemical treatment is insufficient for discharging chemically pre‐treated dairy wastewater to a sewage system, which was actually the main objective of the study. The results showed that the wastewater composition greatly influences the maximum removal efficiencies and also the conditions for optimum coagulation. However, attention to such chemical treatment studies on dairy wastewater has started to accelerate within the last decade in various countries of the world, such as United Arabic Emirates and Scandinavian countries where the targets of applying chemical treatment varied. In Scandinavian countries, biodegradable coagulants have been applied to use the sludge arising from the system for livestock feeding, leading to reuse of sludge. In Arabic Emirates, chemically treated dairy effluents are utilised for irrigation purposes. These recent studies point out that application of chemical treatment to dairy wastewater with various coagulants lead to a variety of utilities apart from being a pre‐treatment alternative.

Following five years of research and development, and a period of controlled commercial use. Albright and Wilson have released details of Accomet C, a chromium compound intended for use as a pre‐treatment chemical.

Investigates the adhesion and corrosion performance of selected silanes in primed galvanised steel. For comparison HDG steel was also treated with a chromate‐free and a chromate‐containing pre‐treatment. All treated panels were painted with three different primers. Corrosion resistance and paint adhesion of the primed panels were studied. Surface energy of the panels was measured by the contact angle method and is reported in terms of the Lewis base component. The corrosion resistance of the panels depended on the combination of the silane and the primer. Vinyltrimethoxysilane (VS) and γ‐aminopropyltriethoxysilane (γ‐APS) treatments improved the corrosion resistance of polyurethane primed panels. γ‐ureidopropyltrimethoxysilane (γ‐UPS) and VS treatments improved the performance of polyester primed panels. A relationship between the base components and the prohesion test results of γ‐UPS and γ‐APS treated panels was found, which indicates that acid‐base interactions improve the adhesion between these two silanes and the primers. γ‐UPS and γ‐APS treated panels also achieved excellent results in the humidity test with all three polymer coatings.

–Prosopis juliflora is a raw material for long-term sustainable production of bioethanol. The purpose of this paper is to identify the best combination of pre-treatment strategy implemented on the lignocellulosic biomass Prosopis juliflora for bioethanol production.

Pre-treatment of lignocellulosic material was carried out using acid, alkali and sonication in order to characterize the biomass for bioethanol production. Prosopis juliflora stem was subjected to steam at reduce temperature (121°C) for one hour residence time initially. Further acid and alkali treatment was carried out individually followed by combinations of acid and sonication, alkali and sonication. Sodium hydroxide, potassium hydroxide, hydrochloric acid, sulphuric acid and nitric acid were used with 3 per cent (w/v) and 3 per cent (v/v) concentration under temperature range of 60-90°C for 60 min incubation time. Sonication under 60°C for 5 min and 40 KHz frequency was carried out. Pre-treated sample were further characterised using field emission scanning electron microscope and Fourier transform infrared spectroscopy to understand the changes in surface morphology and functional characteristics.

In sono assisted acid treatment-based method, nitric acid yields better cellulose content at 70°C and removes lignin that even at increased temperatures no burning was observed.

The paper adds to the scarce research available on the combination of auto hydrolysis coupled with sono assisted acid/alkali hydrolysis which is yet to be practiced.

To investigate the effects of acetylation process as a chemical treatment method to improve the dimensional stability of wood, or as a pre‐treatment step to enhance the dimensional stability of wood by impregnates.

Esterification of two species of wood were carried out by vapour and liquid phase acetylation processes. With the vapour phase acetylation process, wood with different acetyl contents were obtained by changing the length of time of treatment. With the liquid phase acetylation, different acetyl content were obtained by changing the acetylating mixture or by activating wood with acetic acid for different periods of time and at different temperatures prior to the acetylation processes. The acetyl content and the conditions of impregnation improving the dimensional stability were modelled and optimised. The success of acetylation process for improving the affinity of wood towards the impregnation was also demonstrated.

Vapour phase acetylation process was preferable over liquid phase acetylation for improving both water resistance and dimensional stability of wood species examined. Liquid acetylating of wood, as a pre‐treatment step enhanced the effect of impregnates, especially the linseed oil to improve relevant wood properties. The greater improvement was obtained at 3 h impregnation time and 190°C curing temperature for 1 h.

Despite the success in improving the affinity of wood species to novolac by pre‐acetylation, increasing the curing time and curing temperature led to deterioration of the water resistance and dimensional stability.

Pre‐acetylation of the wood provided a practical solution to rendering the natural wood greater water resistance property using commercial impregnates.

The method for acetylation of wood prior to impregnation was novel and could be used for inhibiting wood against moisture absorption during storage.

FOR whatever reason — general wear and tear, change of livery, or metallographic inspection procedures — aircraft are repainted. This is a fact of life that many would wish fictional, since the job is not one which could be described as the cleanest in the world, nor the most pleasant. A typical refurbishment process sequence could be simplified into eight steps: paint stripping; rinsing; cleaning; rinsing; pre‐treatment; rinsing; drying and repainting. This short article deals only with one aspect of the sequence — the pretreatment.