Particle technology as a uniform discipline? Towards a holistic approach to particles, their creation, characterisation, handling and processing!

Particle release from refit operations in shipyards: Exposure, toxicity and environmental implications

European harbours are known to contribute to air quality degradation. While most of the literature focuses on emissions from stacks or logistics operations, ship refit and repair activities are also relevant aerosol sources in EU harbour areas. Main activities include abrasive removal of filler and spray painting with antifouling coatings/primers/topcoats. This work aimed to assess ultrafine particle (UFP) emissions from ship maintenance activities and their links with exposure, toxicity and health risks for humans and the aquatic environment. Aerosol emissions were monitored during mechanical abrasion of surface coatings under real-world operating conditions in two scenarios in the Mallorca harbour (Spain). Different types of UFPs were observed: (1) highly regular (triangular, hexagonal) engineered nanoparticles (Ti-, Zr-, Fe-based), embedded as nano-additives in the coatings, and (2) irregular, incidental particles emitted directly or formed during abrasion. Particle number concentrations monitored were in the range of industrial activities such as drilling or welding (up to 5 ∗ 10⁵/cm³, mean diameters <30 nm). The chemical composition of PM₄ aerosols was dominated by metallic tracers in the coatings (Ti, Al, Ba, Zn). In vitro toxicity of PM₂ aerosols evidenced reduced cell viability and a moderate potential for cytotoxic effects. While best practices (exhaust ventilation, personal protective equipment, dust removal) were in place, it is unlikely that exposures and environmental release can be fully avoided at all times. Thus, it is advisable that health and safety protocols should be comprehensive to minimise exposures in all types of locations (near- and far-field) and periods (activity and non-activity). Potential release to coastal surface waters of metallic engineered and incidental nanomaterials, as well as fine and coarse particles (in the case of settled dust), should be assessed and avoided.

An Overview of the Biolubricant Production Process: Challenges and Future Perspectives

The term biolubricant applies to all lubricants that are easily biodegradable and non-toxic to humans and the environment. The uses of biolubricant are still very limited when compared to those of mineral oils, although this trend is increasing and depends on investment in research and development (R&D). The increase in demand for biodegradable lubricants is related to the evolution of environmental regulations, with more restrictive rules being implemented to minimize environmental impact caused by inappropriate disposal. This study provides an overview of the types, production routes, properties, and applications of biolubricants. Biolubricants are classified as either natural or synthetic oils according to chemical composition. Natural oils are of animal or vegetable origin and are rarely used because they are unstable at high temperatures and form compounds that are harmful to equipment and machines. Synthetic oils are obtained from chemical reactions and are the best lubricants for demanding applications. They are obtained by various routes, mainly by obtaining straight or branched-chain monoesters, diesters, triesters, and polyol esters from vegetable oils. The conversion of triglyceride to esters can be followed or preceded by one or more reactions to improve reactions such as epoxidation and hydrogenation.

Computational Analysis of Imbalance-Based Irregularity Indices of Boron Nanotubes

. Molecular topology provides a basis for the correlation of physical as well as chemical properties of a certain molecule. Irregularity indices are used as functions in the statistical analysis of the topological properties of certain molecular graphs and complex networks, and hence help us to correlate properties like enthalpy, heats of vaporization, and boiling points etc. with the molecular structure. In this article we are interested in formulating closed forms of imbalance-based irregularity measures of boron nanotubes. These tubes are known as α-boron nanotube, triangular boron nanotubes, and tri-hexagonal boron nanotubes. We also compare our results graphically and come up with the conclusion that alpha boron tubes are the most irregular with respect to most of the irregularity indices.

Water Contaminated by Industrial Textile Dye: Study on Decolorization Process

This work aims to investigate possible interferences due to the presence of sodium carbonate on the photodegradation of the reactive Black 5 azoic dye, both in systems containing only titanium oxide and those containing titanium oxide and hydrogen peroxide. The role of hydrogen peroxide is explicitly treated. Sodium carbonate, in fact, is often present in the wastewater of textile industries as it is used in the fiber dyeing phases. The use of TiO2 nanoparticles is emphasized, and the possible danger is underlined. Each system was subjected to ultraviolet irradiation (UV) by varying the exposure time. After the photodegrading tests, the resulting solutions were analyzed by UV-vis spectrophotometry and High-Resolution Nuclear Magnetic Resonance to measure the residual concentrations of dye. The dye degradation curves and reaction rates for different UV exposure times were obtained and discussed as a function of the used additives. All the data are repeated three times, and they differ only by a maximum of 5%. The results indicated a reduction of about 50% of the initial concentration of Reactive Black 5 after 30 min under optimal experimental conditions. The NMR analysis indicated the formation of a series of aromatic structures that were generated by the UV-induced photochemical fragmentation of the original molecule.

Morphology-Controlled Versatile One-Pot Synthesis of Hydrophobic Gold Nanodots, Nanobars, Nanorods, and Nanowires and Their Applications in Surface-Enhanced Raman Spectroscopy

Many previously reported syntheses of gold nanoparticles required lengthy reaction times, complicated operations, high temperatures, or multi-step manipulations. In this work, a morphology-controlled versatile one-pot synthesis of hydrophobic gold nanodots, nanobars, nanorods, and nanowires has been developed. A series of gold nanomaterials ranging from round nanodots, short nanobars, and long nanorods to ultrathin and ultralong nanowires (diameter <2 nm, length >2 μm) have been readily prepared by simply adjusting the feeding ratio of chloroauric acid to oleylamine, oleic acid, and triphenylsilane. The silk-like ultralong and ultrathin nanowires were found to have a single crystalline structure and may have significant potential applications in microelectronics and biosensors. Large sizes of gold spherical nanoparticles were obtained from gold nanodots via a seed-mediated growth approach. These nanoparticles and ultralong nanowires showed excellent surface-enhanced Raman scattering (SERS) activity in organic solvents and, therefore, were employed as efficient organic-soluble SERS substrates for the detection of hydrophobic food toxicants, such as 3,4-benzopyrene, and carcinogens, such as benzidine.

Development and Regression Modeling of Dirt Resistive Latex Façade Paint

A highly dirt-resistant paint for building façades without chemicals harmful to nature and the environment would resolve the unattractive disfigurement of building walls caused by dirt. The current ranking of Pakistan in terms of air pollution is 139th. A set of dirt-resistant paint formulae was constructed with the aid of computer programming. From this set, the best dirt-resistant paint formula was explored and identified. The final determination of the optimum formulation was based on statistically planned experiments conducted in the laboratory and in a natural environment. In order to achieve high-quality results, the best available laboratory equipment were used. The results obtained were analyzed and conclusions were drawn using appropriate statistical techniques. The procedure started with the selection of appropriate raw materials and generation of a target population of 543,143 paint formulations by adopting Basic Language computer programming. The average pigment volume concentration (PVC) percentage was computed using theory and found to be 54.98% for the target population paint formulations, verifying the literature results. Experimentation and statistical analysis were performed to compare the classical conventional agitator with the latest lab equipment such as a nano mill, and it was concluded that the nano mill performs better on average than the conventional agitator in the preparation of paint formulations. Hence, the sample of paint formulations was prepared on a nano mill and tested in the laboratory using advanced available technology for the analysis and comparison of paint properties to determine the best paint formulation. The results were analyzed using the Analysis of Variance (ANOVA) technique, and it was concluded that the newly developed paint has the highest dirt resistance on average. The final selected formula, No. 50 (the newly developed paint), was compared with the three best conventional paints available in the Pakistan market in a natural environment for a period of almost one year. A regression model was also constructed to study the effect of environmental factors like time, temperature, and humidity on the dirt resistance of paints. It was found that the newly developed paint formulation is the most environmentally friendly. It performs equally well as one conventional paint and has higher dirt resistance than two other conventional paint formulations containing harmful chemicals. The regression model of dirt resistance involving variables including time, temperature, and humidity shows that these factors significantly affect the dirt resistance of a given paint at a 5% level of significance. For a given paint, 95.34% of the variation in the dirt resistance is due to and explained by the given factors. The regression model is useful for predicting the average dirt resistance of a given paint with a certain level of confidence. The project exemplifies the work of applied research from conceptualization to successful commercialization in the paint industry.