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The aim of this work is to synthesize neopentyl glycol oligoesters based on adipic acid and rapeseed oil (NOAR) which may be used as the renewable and environmentally acceptable base fluids to replace mineral oils in the future.

Oligomeric intermediates were synthesized in the first esterification of neopentyl glycol with adipic acid and characterized by Gas Chromatography-Mass Spectrometer (GC-MS) to calculate the average oligomerisation degree. NOAR were synthesized in the second esterification of oligomeric intermediates with rapeseed oil fatty acid. The effects of average oligomerisation degree on the viscosity, viscosity index, pour point, oxidative stability and biodegradability of NOAR were investigated; the tribological properties and thermal stability of NOAR were evaluated by four-ball tribometer and TGA, respectively.

Results show that with the increase of average oligomerisation degree from 2.10 to 4.34, the viscosity of NOAR increased from 101.1 to 182.0 (mm2/s) at 40°C and 18.3 to 30.1 (mm2/s) at 100°, respectively, and their oxidation stability can be improved as well. The yields of NOAR were 83.3-89.4 per cent, and the evaluated properties were as follows: viscosity index of over 200, pour point of below −43°C, biodegradation rate of more than 96 per cent, maximum non-seizure load (PB value) of 784 N, wear scar diameters of 0.40 mm and thermal decomposition temperature of higher than 300°C.

This work provides a method to synthesize rapeseed oil-based oligoesters which can serve as the renewable and environmentally acceptable base fluids with tunable viscosity by controlling the oligomerisation degree of esterification.

The purpose of the present study is first to develop a hydroxyl-functionalized ketonic resin for coating applications and to establish a standard characterization protocol; second, to quantify the effects of various operating parameters on resin properties and to develop mathematical models to predict the product properties; and third, to carry out the compatibility study between the in-house developed resins and commercially available resins.

Self-polymerization reactions were conducted in a batch reactor. Effects of reaction time, temperature, catalyst concentration and reactor pressure on product properties have been studied. Hydroxyl value, iodine value, solubility, rheology, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and the X-ray diffraction (XRD) analysis were carried out to characterize the product properties. Mark–Houwink correlation was used to predict molecular weight of the resins.

The study shows that hydroxyl value and softening temperature (ST) of the product increased with the increase of reaction temperature, duration of reaction and alkali concentration. However, the solubility value of the resins decreased with the increase of temperature, time and alkali concentration. Regression models were developed to predict the optimum conditions for obtaining a desired quality of resin. The number-average molecular weight of the developed resins was in the range of 450-1150. The products are thermally stable up to around 200°C, and adequately soluble in many commercial solvents.

The ketonic resin can be used as a substitute of phenolic resins which are prepared from more hazardous materials monomers such as phenolic and aldehyde compounds.

The resin can be used as a substitute of more hazardous materials such as phenolic and aldehyde compounds.

This paper details the synthesis of ketonic resin from cyclohexanone and its compatibility. It also investigates the optimization of operating parameters to obtain a desire product.

The use of lubricants in food production and processing is widely known. Over time, the regulations and requirements for lubricants in food machinery have evolved to include a wide variety of product technology. This technology includes many synthetic based formulated lubricants. This paper will focus on the types of lubricants available for use in the food industry, as well as the benefits and potential drawbacks of each lubricant type. It will also address the changing legislation surrounding the use of lubricants in food manufacturing and processing equipment.

This paper aims to address the polymerization of 1-decene by [Emim]Cl/AlCl₃ ionic liquid and the film-forming properties of the product compared with commercially available base stocks.

Experiments were carried out to investigate the influence of [Emim]Cl/AlCl₃ mole ratio, catalyst dosage, reaction temperature, reaction time and water on the polyreaction. Poly alpha-olefin (PAO) is prepared under optimal reaction condition. Film-forming properties of PAO have been compared with those of Group I, Group II and Group III base stocks, which are selected with approximately the same viscosity.

Experimental results show that after a 4-h reaction time, yield of PAO can be higher than 85 per cent and viscosity index can be up to 160 with [Emim] Cl/AlCl₃ mole ratio of 2:1, catalyst dosage of 3 per cent wt. and water content of 20 ppm. A strong influence of water on reaction is observed. With approximately the same viscosity, PAO shows the superiority in film thickness at low-sliding speeds compared with Group I and Group II base stocks. At high temperature, PAO provides a thicker film than other base stocks.

In recent years, there has been considerable interest in ionic liquids. As a novel catalyst, it has so many advantages including low corrosion, low toxicity, low cost and a potentially wide range of properties compared with traditional catalysts. This paper reports the polymerization of 1-decene by [Emim]Cl/AlCl₃ ionic liquid and the study on lubricating properties of PAO compared with mineral base stocks.

This paper aims to depict the mechanistic role of vitamin D on dementia prevention, relief of the severity and the complication of the disease. All papers indexed in scientific databases, including Scopus, Elsevier, PubMed, Embase and Google Scholar between 2000 and 2021 were extracted and discussed. To present the mechanistic role of vitamin D in declining the severity of dementia, keywords including dementia, vitamin D, oxidative stress, inflammation, amyloid beta-Peptides were used.

Dementia is a prevalent cognitive disorder worldwide, especially in elderly people, which is accompanied by serious disabilities. Besides genetic, biological and lifestyle factors are involved in the incidence of dementia. An unhealthy diet along with micronutrient deficiencies are among modifiable factors. Vitamin D is one of the important micronutrients in brain health. Besides the involvement in gene expression, bone mineralization, apoptosis, inflammation, skeletal maturation, neurotropic action and hemostasis of phosphate and calcium, vitamin D also exerts neuroprotective effects via genomic and non-genomic pathways.

Vitamin D up-regulates the expression of various genes involved in dementia incidence via various mechanisms. Decreasing oxidative stress and the neuro-inflammatory cytokines levels, regulation of the expression of alternated Proteins including Tau and Amyloid-ß, calcium homeostasis in the central nervous system and also vascular are considered main mechanisms.

Considering the importance of diet in preventing dementia, adherence to a healthy diet that provides essential nutrients to brain function seems to be urgent. Controlling serum levels of vitamin D periodically and providing vitamin D by related sources or supplements, if there is a deficiency, is recommended. Future studies are needed to clarify other related mechanisms.

To study the drying effects of cobalt, manganous and mixed salts for their catalytic action in cross linking reactions occurring during the creation of an alkyd resin film.

The driers of Co‐octoate, Mn‐octoate, Mn‐octoate with an active organic ligand, and mixed drier containing the salts of Mn, Ca, and Zn were employed in the cross linking reactions of alkyls. The study verified the possibility of using manganese as an active cation in catalytic curing reactions. The course of the cross‐linking of alkyds was monitored on a model system of the reactions of drier with ethyl linoleate, using FTIR spectroscopy. Reaction‐rate constants corresponding to the first phase of cross linking were obtained. The driers under scrutiny were used to identify the time of the drying of alkyd resin modified with flax oil. The final phase of the cross linking reactions was monitored by means of measurement the hardness of the created alkyd film depending on time.

The driers under scrutiny were found to have catalytic effects in auto‐oxidation reactions. Very high efficiency was found with all of the driers. The highest efficiency was found with Co‐octoate resulting in the development of the highest hardness of coatings. Mn‐octoate and mixed driers show a steeper increase in film hardness than Co‐drier, yet the final films are suppler.

The driers studied can be conveniently used to accelerate creation of alkyd coatings modified with natural oils and designed for both industrial and decorative purposes.

The method of identifying the kinetic parameters of the cross‐linking reactions of alkyds is relatively new and facilitates the localisation of driers that are optimum for specific paints formulations. Of benefit is also the study of Mn‐driers that are more environmentally acceptable than Co‐driers.

This paper aims to examine the role of different polyalkylene glycol architectures in improving the hydrolytic stability of natural and synthetic esters.

Hydrolytic stability measurements were conducted using a modified ASTM D2619 test method in which several polyalkylene glycol chemistries were examined at concentrations of up to 10 per cent in a selection of esters.

The inclusion of triblock copolymers derived from ethylene oxide (EO) and 1,2-propylene oxide (PO) and with an EO content of about 30 per cent produced significant improvements in the hydrolytic stability of natural and synthetic esters. Stability improved with increased concentration of the triblock.

The study did not evaluate the vast array of polyalkylene glycol structures that can be derived from other higher alkylene oxides.

Improving the hydrolytic stability of esters can offer the possibility of creating longer life environmentally acceptable lubricants (EALs).

This discovery should allow longer life EALs to be designed thereby using less raw materials over a determined period. It may also allow more replacement of conventional hydrocarbon lubricants.

Triblock copolymers are rarely used in lubricants. Their use as components of ester-based EALs is new.

The paper aims to investigate the drying effect exhibited by pigments combined with a Co(II) salt of 2‐ethylhexanoic acid (Co(II)) in an alkyd resin modified by soya bean oil.

Paint hardening was studied by means of a method that follows the progress of alkyd film drying. Another important method was employed to monitor the gradually increasing hardness of the drying films. Hardness of thin films was measured by the Persos method. ZnO, ZnO nanoparticles, V₂O₅, ZnS and TiO₂ were used to study the effect of solid inorganic pigments on alkyd film drying. The pigment particles were characterised by scanning electron microscopy. The investigated pigments were combined with a constant amount of the Co(II) drier that acts in the system as a homogeneous catalyst, while the investigated pigments played the role of heterogeneous catalysts.

Using certain pigments as catalysts in drying, alkyd resins brings about new findings concerning the function of fillers and pigments in paint films. ZnO nanoparticles substantially accelerate film drying and moreover, the resulting films exhibit substantially higher hardness than films containing other inorganic pigments. To prepare films exhibiting higher hardness within a shorter time, one may also use ZnO microparticles or ZnS. TiO₂ and V₂O₅ were identified as pigments that either do not take part in the drying process or reduce the hardness of the resulting film.

The investigated catalytic system pigment/Co(II) drier can be advantageously used to accelerate the formation of alkyd paints modified by natural oils both for industrial and decorative purposes. It was established that hardness of paint films containing ZnO nanoparticles is twice as high as that of films containing only the Co(II) drier without any pigment. This finding makes new applications of alkyd paints possible in all instances where higher hardness is required.

Considering pigments as heterogeneous catalysts in systems producing films by the oxypolymerising mechanism is a new approach that gives rise to new and original solutions.

The aim is to demonstrate corrosion inhibition capabilities of several isoxazolidines, containing hydrophobic substituents and having varying degree of steric congestion around nitrogen.

A number of isoxazolidines were prepared. Corrosion inhibition efficiencies of these organic compounds were determined by gravimetric and electrochemical methods, using carbon steel as the substrate metal and 0.5 M H₂SO₄ at 40‐70°C as the corrosive environment. Concentration of inhibitor was varied between 5 and 400 ppm.

Increase in steric congestion around the nitrogen centre and hydrophobic chain lengths as well as increase in temperature (in the presence of the inhibitor in the higher concentration range 100‐400 ppm) were found to increase the corrosion inhibition efficiency of the isoxazolidines. Electrochemical measurements corroborated these results. Thermodynamic parameters (ΔG_ads⁰,ΔH_ads⁰,ΔS_ads⁰) for the adsorption process and kinetic parameters for the metal dissolution (or hydrogen evolution) reaction were determined.

This is the first time the corrosion inhibition characteristics of isoxazolidines, an important class of readily accessible compounds, have been evaluated in H₂SO₄ medium.

The purpose of this paper is to understand the direct impact of social capital and the influence of market-based capabilities as intervening variables on the export performance of small and medium-sized enterprises (SMEs) in Ghana.

Questionnaire-based survey was used to collect data from top executives and senior managers of exporting companies in Ghana. Data obtained were analysed using the structural equation modelling.

The findings revealed that social capital of SMEs exert the greatest influence on their export performance. Innovation and marketing capabilities are also key drivers of export performance among SMEs as they fully mediate the social capital–export performance relationship. Notwithstanding, marketing capabilities appear to exert a greater influence than innovation capabilities on the export performance of SMEs.

The study used perceptual measures of international performance by managers of SMEs in the Ghanaian exporting sector making it difficult to determine respondent bias.

Managers of exporting firms should build stronger relationships with their customers and suppliers who contribute significantly to their export performance. SMEs would also have to hone their innovation and marketing skills as strategic components in enhancing their export performance.

Market-based resources such as marketing and innovation should not be taken for granted by SMEs in the export business.

The study offers some lessons on how small firms can sharpen their marketing and innovation capabilities to derive export performance benefits from social capital. Theoretically, while the findings offer strong evidence reinforcing the DC theory, an exploration of the nexus of the theories brings to the fore the need to reassess the resource-based view and SC theories.