Sealing The Cracks in the Wear Layer of the Road Surface by Friction against a Rotary Active Element

The main objective of the research paper is the theoretical and experimental analysis of the method proposed for sealing (clogging) cracks in asphalt, by means of a cylindrical bitumen bar, enriched with plastic and rubber granules (obtained from the use of waste), which melts and infuses into the cracked zone by rotation and friction against it. After analyzing the technical characteristics of the sealed area and the time required to apply the bitumen layer, this method can be chosen in the future to the detriment of the expensive operations of partial milling of the cracked wear layer, making possible the repair of cracks by sealing(clogging), using the friction procedure. The research results highlighted the diminution of road maintenance costs using the method of friction, the decrease of cracks repair time, maintaining the initial characteristics of the repaired area, incorporating a waterproofing material (plastic and rubbber granules from recycled waste), keeping the wear layer in good conditions, possibility of embedding an intelligent system of traffic monitoring at low costs etc.

Design of a VTOL UAV for Anti-poaching Surveillance Missions in the Danube Delta

The main objective of the research paper is the theoretical and experimental analysis of the method proposed for sealing (clogging) cracks in asphalt, by means of a cylindrical bitumen bar, enriched with plastic and rubber granules (obtained from the use of waste), which melts and infuses into the cracked zone by rotation and friction against it. After analyzing the technical characteristics of the sealed area and the time required to apply the bitumen layer, this method can be chosen in the future to the detriment of the expensive operations of partial milling of the cracked wear layer, making possible the repair of cracks by sealing(clogging), using the friction procedure. The research results highlighted the diminution of road maintenance costs using the method of friction, the decrease of cracks repair time, maintaining the initial characteristics of the repaired area, incorporating a waterproofing material (plastic and rubbber granules from recycled waste), keeping the wear layer in good conditions, possibility of embedding an intelligent system of traffic monitoring at low costs etc.

Recent Advances in Chemical Sensors for Soil Analysis: A Review

The continuously rising interest in chemical sensors’ applications in environmental monitoring, for soil analysis in particular, is owed to the sufficient sensitivity and selectivity of these analytical devices, their low costs, their simple measurement setups, and the possibility to perform online and in-field analyses with them. In this review the recent advances in chemical sensors for soil analysis are summarized. The working principles of chemical sensors involved in soil analysis; their benefits and drawbacks; and select applications of both the single selective sensors and multisensor systems for assessments of main plant nutrition components, pollutants, and other important soil parameters (pH, moisture content, salinity, exhaled gases, etc.) of the past two decades with a focus on the last 5 years (from 2017 to 2021) are overviewed.

Crosslinked Chitosan Binder for Sustainable Aqueous Batteries

The increased percentage of renewable power sources involved in energy production highlights the importance of developing systems for stationary energy storage that satisfy the requirements of safety and low costs. Na ion batteries can be suitable candidates, specifically if their components are economic and safe. This study focuses on the development of aqueous processes and binders to prepare electrodes for sodium ion cells operating in aqueous solutions. We demonstrated the feasibility of a chitosan-based binder to produce freestanding electrodes for Na ion cells, without the use of organic solvents and current collectors in electrode processing. To our knowledge, it is the first time that water-processed, freestanding electrodes are used in aqueous Na ion cells, which could also be extended to other types of aqueous batteries. This is a real breakthrough in terms of sustainability, taking into account low risks for health and environment and low costs.

Geochemical, Mineralogical and Isotopic Fracturing during the Progressive Evaporation of Chott Djerid Brine (Southern Tunisia)

Djerid Chott, in southwestern Tunisia, is one of the biggest salt lakes in the world. This work follows the specific precipitation of evaporites through progressive evaporation of Chott Djerid brines using geochemical, isotopic and mineralogical approaches, to explain the intricacy of the working of saline frameworks controlled basically by climatic driving and the underlying geochemical structure acquired from the geographical system. Toward the finish of every evaporation step, solid and liquid samples went through analyses. Djerid brine is remarkably saline (427.7 g/l) and it is supersaturated contrasted with halite. The outcomes indicated that the Chott Djerid brines shaped fundamentally Cl--Na+-SO4- type geochemistry. Added to halite and gypsum as significant minerals, other minor minerals including carnallite, hexahydrite and sylvite were recognized in various phases of progressive evaporation of Djerid brine. Regardless of their low costs, significant minerals are of geo-economic interest because of their high amounts of production. Then, minor valuable minerals secure their geo-economic interest from their excessive costs. In this work, we find the window of precipitation of these valuable minerals' at the evaporation paces of 80% and 100%.

Framework structure materials in photovoltaics based on perovskites 3D

The inorganic and hybrid organic / inorganic perovskites based on lead halide and derived materials (alloys) having the formula ABX3 are emerging as a new and innovative family of absorber materials for the conversion of solar energy into electricity in photovoltaic systems. Thanks to their composition, perovskites and derivatives have exceptional optical, electrical and structural properties with high absorption of light in the visible solar spectrum and good mobility of charge carriers generated by photons facilitating the extraction of electric current. Due to these important properties, perovskite solar cells combine a high efficiency of conversion of light into electricity with great ease of preparation and synthesis at very low costs via simple deposition techniques. In this article we review the structural and optoelectronic properties of perovskites 3D exhibiting photovoltaic properties, we are also interested in the operating principle of perovskite-based solar cells, charge transport materials and associated architectures. Simple fabrication techniques and issues with stability and hysteresis are also discussed.

Electrochemical Devices to Monitor Ionic Analytes for Healthcare and Industrial Applications

Recent advances in electrochemical devices have sparked exciting opportunities in the healthcare, environment, and food industries. These devices can be fabricated at low costs and are capable of multiplex monitoring. This overcomes challenges presnted in traditional sensors for biomolecules and provides us a unique gateway toward comprehensive analyses. The advantages of electrochemical sensors are derived from their direct integration with electronics and their high selectivity along with sensitivity to sense a wide range of ionic analytes at an economical cost. This review paper aims to summarize recent innovations of a wide variety of electrochemical sensors for ionic analytes for health care and industrial applications. Many of these ionic analytes are important biomarkers to target for new diagnostic tools for medicine, food quality monitoring, and pollution detection. In this paper, we will examine various fabrication techniques, sensing mechanisms, and will also discuss various future opportunities in this research direction.

Virtually the same? Evaluating the effectiveness of remote undergraduate research experiences

In-person undergraduate research experiences (UREs) promote students' integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration. To address this, we investigated indicators of scientific integration for students who participated in remote life science URE programs in summer 2020. We found that these students experienced gains in their scientific self-efficacy and scientific identity similar to results reported for in-person UREs. We also found that these students perceived high benefits and low costs of doing research at the outset of their programs, and their perceptions did not change despite the remote circumstances. Yet, their perceptions differed by program, indicating that programs differentially affected students' perceptions of the costs of doing research. Finally, we observed that students with prior research experience made greater gains in self-efficacy and identity, as well as in their perceptions of the alignment of their values with those of the scientific community, in comparison to students with no prior research experience. This finding suggests that additional programming may be needed for undergraduates with no prior experience to benefit from remote research.

The role of numerical modeling in scientific fire investigation

Fire risk is perhaps the most common risk in the category of special emergencies, being a phenomenon that affects important areas of economic and social life, such as buildings, industrial facilities, public spaces, forests, crops, or transportation. Scientific investigation of fires is constituted as a set of organized actions, of technical nature, undertaken to determine the causes that led to the occurrence of fires, the source of ignition, and the circumstances that favored the event. Numerical fire modeling is a widely recognized and accepted tool for analysis in fire research. The results of the investigation carried out on-site are compared with the results of fire evolution obtained by computer simulation, using numerical models based on known input data, to verify different hypotheses regarding the cause of the fire. The advantages over experimental methods are expressed by low costs and substantial time savings. Moreover, several simulations can be run simultaneously, for different scenarios of the event or the analysis of different consequences. The paper presents the main advantages that numerical modeling by FDS methods brings in the technical-scientific expertise of fire, with implications in the data analysis, development, and testing of hypotheses, respectively in the selection process of the final hypothesis. words.

Wastewater Treatment by Enhanced H2O2 – Based Advanced Oxidation Process (AOP) Methods: A Review

The development of industries leads to large amount of organic wastewater that contains phenol and dyes. For the treatment of these pollutants, the applications of H2O2 based – AOP have advantages in less pollution, low costs and high efficiency. In order to promote the degradation effect of H2O2, researchers used several methods to strengthen the effect of H2O2 based – AOP. This article mainly reviews the development of catalysts of the strengthened Catalytic Wet Hydrogen Peroxide Oxidation (CWPO), Fenton-like and other assistant-H2O2 systems in the degradation of phenol and dyes recent years. Challenges and development directions concerning catalysts in the future are discussed.