Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation

The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

High Frequency Pressure Monitoring of the Re-Fracturing or Continuous Pumping Operations: Case Studies

The opportunity to refracture low-producing horizontal wells, which have been fractured few months before is getting more and more popular in the last few years. It provides the opportunity of restoring production without drilling new wells, which might be economically feasible especially in the oil and gas low price environment. However, the success rate of refracturing operations is usually low, mainly driven by the inability to properly stimulate the entire horizontal section. Consequently, many operators do not widely deploy this efficient technology. In contrast, completing a newly drilled well with plug and perf technology allows to individually treat from forty to sixty or even more individual compartments in the lateral section while refracturing attempts to retreat the entire lateral in the absence of any isolating device while trying to cover the entire lateral. There are at least two key factors affecting this operation. First is diversion technology: without efficient chemical diverters, which allow to temporarily block recently treated intervals and divert the stimulation fluid to different open sections of the well is extremely challenging. These diverters should normally be able to hold pressure differentials up to thousand psi or more. Attempting a treatment without this technology, aka a "blind frac" is not an option in many cases. The second factor is monitoring technology: The ability to recognize whether a zone has been successfully stimulated, to decide on the deployment of diverting technology or the further addition of stimulation fluid, to sponsor lateral coverage with minimal risk of premature screen out becomes of utmost importance for the successful outcome of hydraulic refracturing operations. In the absence of either of the aforementioned factors hydraulic refracturing may become inefficient and yield uneconomic success. This paper presents how the application of novel diverters, combined with proper hydraulic fracturing fluid selection, sound engineering design and more importantly hydraulic fracturing monitoring provide a new opportunity for the deployment of hydraulic refracturing to provide significant production increase and enhance recovery factor.

УПРАВЛІННЯ ЕНЕРГОЕФЕКТИВНІСТЮ ТА ЕНЕРГОЗБЕРЕЖЕННЯМ НА БАЗІ УНІВЕРСИТЕТСЬКОГО ЕНЕРГО-ІННОВАЦІЙНОГО ХАБА ЗНАНЬ

This paper offers an argument for the need to providing further research on improving energy efficiency and searching for modern management methods based on the university energy innovation knowledge hub. The findings have revealed that the specific energy consumption in the Ukrainian economy is unjustifiably higher than that of other European countries and countries with transitive economies. It is noted that economic losses are becoming increasingly apparent in the context of high cost of imported energy resources, low level of energy security, incompetitiveness of industries and significant environmental wastes. The research methodology entails the principle of studying and summarizing factual data on enhancing energy management and quality management systems, as well as the university documentation. To attain the research agenda, the following methods have been employed: the system and structural analysis techniques, management theory, methods of diagnostics and identification, graph theory as well as energy balance methods. The study presents a mechanism of energy efficiency and energy saving management based on the university energy innovation knowledge hub. The findings demonstrate that such a mechanism is able to overcome the rejection by economic actors of innovation technologies in general and energy efficient technologies in particular. The proposed mechanism of energy efficiency and energy saving management based on the university energy innovation hub challenges the implementation of specific economic measures that should include such elements as incentives (motivators) for energy saving, energy market infrastructure and energy efficient technology, energy projects funding sources and tools. The conclusions resume that in modern realia, higher education institutions should promote a shift from a formally declared energy saving policy towards a University energy efficiency economy pattern as an energy autonomy driver, building a strategy for combining indicative and market functions in ensuring energy efficiency.

MinION™ Nanopore Sequencing of Skin Microbiome 16S and 16S-23S rRNA Gene Amplicons

Human skin microbiome dysbiosis can have clinical consequences. Characterizing taxonomic composition of bacterial communities associated with skin disorders is important for dermatological advancement in both diagnosis and novel treatments. This study aims to analyze and improve the accuracy of taxonomic classification of skin bacteria with MinION™ nanopore sequencing using a defined skin mock community and a skin microbiome sample. We compared the Oxford Nanopore Technologies recommended procedures and concluded that their protocols highly bias the relative abundance of certain skin microbiome genera, most notably a large overrepresentation of Staphylococcus and underrepresentation of Cutibacterium and Corynebacterium. We demonstrated that changes in the amplification protocols improved the accuracy of the taxonomic classification for these three main skin bacterial genera. This study shows that MinION™ nanopore could be an efficient technology for full-length 16S rRNA sequencing; however, the analytical advantage is strongly influenced by the methodologies. The suggested alternatives in the sample processing improved characterization of a complex skin microbiome community using MinION™ nanopore sequencing.

Microwave Heating as an Innovative Road Maintenance Technology: Aging Effect on Binder and Feasibility Evaluation

The microwave heating/healing technique is regarded as a green maintenance approach for asphalt pavements thanks to its promising environmental and economic benefits. However, the main concern about this technology is represented by the possible aging effect generated on bituminous binders. Currently, there is a significant lack of studies dealing with this topic. Based on these premises, the main purpose of this study is to appraise the feasibility of implementing microwave-based maintenance operations considering the associated aging effect. The assessment of fatigue life after cyclic microwave heating (MH) based on a linear amplitude sweep (LAS) test and the changes in the chemical groups detected through Fourier transform infrared (FTIR) spectroscopy document the aging phenomenon. The results indicate that the microwave aging degree on bituminous binder is nonlinear with MH cycles. The microwave radiation causes a distinct aging impact on binders during the first 10 cycles, then the values become constant. Furthermore, a feasibility analysis of MH technology is developed, encompassing four main multidisciplinary aspects: evaluation of microwave aging degree, working mechanism of MH equipment, safety assessment, and economic and ecological considerations. Despite the associated aging issue, the MH method is an efficient technology, considering its various advantages (i.e., rapidity of execution, uniform and non-pollutant treatment, and deep penetration). Meanwhile, the use of steel slag as a microwave absorber bolsters the sustainability of MH technology. This study provides a new perspective to evaluate the microwave heating technique in road engineering comprising the generated aging effect. Practice-oriented recommendations are also formulated regarding the safe implementation of MH technical operations.

Investigation the combined effects of exhaust gas recirculation (EGR) and alcohol-diesel blends in improvement of NOX-PM Trade-off in compression ignition (CI) diesel engine

The increasing demand to decrease the greenhouse gas emissions leads to find clean fuel and renewable fuel such as ethanol and methanol that good replacement of oil-derived transportation fuels. The combined effects of alcohols blends (ethanol-diesel and methanol-diesel) and with and without EGR on NOX-PM Trade-off in diesel engine were investigated under variable engine loads and speeds. The EGR is considered efficient technology to reduce the NOX emissions in compression ignition (CI) diesel engines. The current study highlighted on the trade-off between nitrogen oxides (NOX) and particulate matter (PM). The oxygenating content in the ethanol blend (E10) and methanol blend (M10) decrease the PM concentrations in the exhaust pipe compared to the diesel fuel for different engine operating conditions with keep NOX emissions in the moderate level. It was found that the NOX/PM concentrations significantly decreased from the combustion of E10 and M10 under variable engine loads and speeds.

Rheological characteristics of steel in continuous roll casting-rolling

Problems. In the process of obtaining a strip in a casting and rolling device, the question arises of combining the process of hot rolling of the solidified material and the process of crystallization of the liquid melt. This makes it possible to implement an efficient technology for producing thin-sheet products. Purpose of the study. Determination of rational parameters for performing mathematical modeling of material behavior during roll casting requires clearly defined recommendations. The material for the rolling process is steel. The starting material was used in solid, solid-liquid and liquid states. Implementation technique. The analysis of the properties of steel was carried out on the basis of the results of experiments obtained at the Physico-Technological Institute of Metals and Alloys of the National Academy of Sciences of Ukraine. To analyze the rheological properties of steel, the dependences of the yield stress for alloyed and carbon steels were used in a certain temperature range. The selected temperature range includes solidus and solid-liquid state of steel, located above 0.8 melting point. Research results. Based on the research results, the analysis of the rheological properties of steel in solid, solid-liquid and liquid states during continuous casting-rolling on rolls was carried out. The use of the obtained dependencies makes it possible to perform mathematical modeling of the deformation and hydrodynamics of the material during continuous casting-rolling of steel strips using roll casting-rolling devices. Conclusions. The constructed dependences, together with studies of the viscosity of steel in the liquid state and the resistance of steel to deformation in the solid state, most fully describe the rheological properties of steels during casting-deformation processes. The obtained dependences will make it possible to implement an ultra-efficient technology for producing thin-sheet rolled products.

Nanoremediation: Nanomaterials and Nanotechnologies for Environmental Cleanup

Different global events such as industrial development and the population increment have triggered the presence and persistence of several organic and inorganic contaminants, representing a risk for the environment and human health. Consequently, the search and application of novel technologies for alleviating the challenge of environmental pollution are urgent. Nanotechnology is an emerging science that could be employed in different fields. In particular, Nanoremediation is a promising strategy defined as the engineered materials employed to clean up the environment, is an effective, rapid, and efficient technology to deal with persistent compounds such as pesticides, chlorinated solvents, halogenated chemicals, or heavy metals. Furthermore, nanoremediation is a sustainable alternative to eliminate emerging pollutants such as pharmaceutics or personal care products. Due to the variety of nanomaterials and their versatility, they could be employed in water, soil, or air media. This review provides an overview of the application of nanomaterials for media remediation. It analyzes the state of the art of different nanomaterials such as metal, carbon, polymer, and silica employed for water, soil, and air remediation.

A Bright, LED-Lit Future for Ocean Sciences

LEDs have taken over the global lighting market. Now it’s time for this versatile, low-cost, and energy-efficient technology to illuminate oceanic processes.