Research Highlights in Science and Technology Vol. 2

Experimental research, both in situ and in the laboratory, allows obtaining the cumulative effect of all determining factors, without the possibility of separating the effects of each one. Due to this fact, as well as because mining develops in different geomechanical conditions, specific to each deposit or even part of the deposit, the problem of ensuring the stability by evaluating the pressure manifestation regime has a local aspect. The results of these researches can be used in order to: improve the existing support monographs, by choosing the optimal support density; establish a correct support technology; establish the appropriate difference between the digging front and support front, etc.; design new types of support; assessment of the effectiveness of the new sup-port technologies in the given geomechanical conditions; optimization of supporting monographs that must be analyzed from the point of view of maximum satisfaction of the required conditions on the work by its role in the production process, throughout its existence, with minimal execution, maintenance and exploitation expenses and in perfect conditions of work safety. For this purpose, the measurement methods and equipment must focus on determining: the movement of the surrounding rocks; the deformations of the underground work profile; the displacements and deformations of the support system; and the loads on the support. Most problems related to mining pressure and mining stability in the underground activity domain must be solved by considering the time behavior of rocks through an approach of the interaction amidst the rock massif, support system, time through the elastic, viscous, and plastic models, namely a rheological approach. To select a rational support system, one must be aware of the sustainment solicitation at various time intervals. Only in analytical research, where the massif is studied and characterized in terms of rheological behavior, is the change in sustainment in time highlighted. The gradient method used in this case is based on the evolution of the final deformations at a given time in comparison to their previous evolution. The paper is divided into two sections: experimental and interpretation of experimental data, which demonstrate the author's methodology for assessing the rheological behavior of analyzed andesite as a result of theoretical and experimental research on the analyzed rock types.  Based on the deformation and the time curve of the horizontal mining work contour, the mathematical function was established, which expresses the law of sought deformation. At the same time, the rheological model capable of describing the behavior under a load and under extremely adverse conditions is proposed.

Anti-graffiti coatings were synthesized from polyurethane with varying    concentration of silicon modified polyacrylate with an - OH functional group. Various tests for evaluating the graffiti resistance of the coating included the measurements of contact angle of water drop on the sprayed coating, and visual evaluation of stain removal and measurements of colour change. It was shown that the best performance was achieved by 5 wt. % of Silicone polyacrylate in pristine PU which demonstrated 95% stain removal. Despite having low mechanical properties of these coatings, they demonstrated remarkable graffiti resistance. In order to improve the mechanical properties of the coatings, nano-particle inclusion was considered. For improving mechanical properties, such as surface hardness, elastic modulus, and scratch resistance, nano-silica particles were added. It was assured to have a coating with even distribution of nano-silica particles.  A 5 wt% nano-silica particles were found to create such coating with composition PU-5 wt% silicone polyacrylate. Measurements of colour changes revealed that the inclusion of nanosilica particles had no impact on the material's resistance to graffiti.  

Micronutrients are essential for the human body. The low content of micronutrients in meals can result in malnutrition. Therefore, the production of crops containing micronutrients is important. This study aims to discuss essential micronutrients and increase the availability of micronutrients to edible parts, including grains and leaves. Essential micronutrients for humans are Zn (zinc) and Fe (iron) because iron deficiency can result in anemia, poor health during pregnancy, and decreased immune function. Zinc is essential for plant growth and development, and a low concentration of zinc can result in leaf necrosis. Foliar application and abundance of microbial in soil are suggested to increase the availability of micronutrients to the crops and edible parts of crops. The foliar application raises the micronutrient content in edible parts because of its accessibility to transport the micronutrients from leaves to grains or other plant tissue. Foliar application can help crops to recover from leaf necrosis. Microbes in the soils, such as Acinetobacter and Rhizobium leguminosarum, can increase iron availability, so crops do not show the symptoms of iron deficiency. Other approaches, such as manure and slow-release fertiliser, can be suggested to increase micronutrient availability in crops.

The paper presents a model of a communication system between a vending machine, an end user and a service administrator. The designed model consists of a multimedia module, a control module and a communication module. The function of the multimedia module is to provide information about availability, prices, procedures for ordering products from the vending machine, etc. The system is managed by software that is installed on a server, a user device and a control unit. The communications used are made up of an infrastructure allowing two or more devices to exchange information two-way through the Internet. The designed model of the system is protected as a valid utility model under the number 2017003813U. Overall, the model purposes to progress user experience and operational competence of vending machines over and done with a well-designed communication system.

Water is a fundamental resource for human civilization, yet there is a critical water shortage happening all across the world in the twenty-first century, which is creating a problem. In some areas of underdeveloped nations, people drink water that has been extensively polluted and comes from rivers that are home to deadly diseases. The study suggests employing two techniques, photocatalytic semiconductor and Photo Fenton, as an enhanced oxidation process to get rid of different types of water impurities and offer an efficient water treatment solution. Water samples were taken from the Couva River in Trinidad and tested using the Photo Fenton process with Titanium Dioxide catalyst. To remove contaminants, the procedure was applied to the samples of river water. The physiochemical criteria that determine the properties of safe water were thus used to evaluate the reaction using both approaches. The two techniques effectively eliminated between 80 and 100 percent of the contaminants that were detected in the river sampled. Also noticed was that variations in Titanium Dioxide concentration correlated with changes in reactivity and degradation rates. Light absorption often reduces dramatically as titanium dioxide concentration rises to saturation. It was also discovered that the rate of degradation was directly correlated with light intensity.  This demonstrates the technology's potential for getting rid of water pollutants. The lower cost of the technology is a crucial benefit of this study, particularly for resource-constrained developing nations.

Radar system proves to be a boon for the military based applications in detecting the enemies and identifying their locations on map. The recent advancement in the system includes applications such as air traffic control and remote sensing.The paper will provide an analysis of Radar Signal Processing to detect the range of the targets, radar cross section and direction finding. It includes that target is stationary under low noise condition and high noise conditions, radar is stationary while the target is moving under the influence of noise, interference and clutter. Another very important parameter being identified is Radar Cross Section (RCS) using approximate method for detecting the target. In this research, Signal processing methods are given for the detection of stationary and moving targets. These approximate methods are less time consuming then the exact techniques of target imaging.Various experiments have been simulated using MATLAB and simulink.

The aim of our study was to investigate whether social interactions between individual wildebeest can generate the empirical power law distributions of wildebeest aggregations. Animals are often found in groups such as fish schools, bird flocks, insect swarms, and ungulate herds. Being in a group helps members to engage in different behavioral activities such as in foraging, predator avoidance, and resistance to toxic environmental conditions, reproduction or socialization. In this study, we present the power law, truncated power law and the exponential distribution. We also quantified the distribution of real herds by analyzing the frequency distribution of wildebeest counts in aerial survey images collected in 2015. We then used a Lagrangian model of animal interactions to simulate individual movement and herd aggregation patterns. The simulations of our agent-based model exhibited characteristic aggregation patterns that were most similar to the empirical data. We observed a close match between parameters from the empirical data and agent based model. These parameters include the scaling parameter from the power law (\(\alpha\)) and the standard deviation \(\sigma\). With parameter values that matched empirical distributions, we fitted the model. Our analysis of the empirical data shows that the aggregation patterns of wildebeest herds are governed by a truncated power law. We contend that social interactions between individual wildebeest can explain this behaviour.

The present review summarizes the main ideas, precises the contributions and provide a recommendation for future researches regarding multi agents systems and Green Supply Chain management. Green supply chain issues have attracted a lot of attention in recent years with growing awareness of environmental concerns. This has drawn the considerable world-wide attention of academics and practitioners. However, coordination and collaboration among all stakeholders are challenging during implementation. As a result, numerous GSCM models and frameworks, including multi agent systems (MAS), are suggested to lessen the complexity of the supply chain. Recycling of used products and the related logistics management pose a significant challenge to manufacturing industries. The adopted research methodology is to build a literature review to bring knowledge on this topic based on already existing literature. The proposed work may offer an effective methodological foundation for resolving the GSCM modelling and collaboration problem using a multi-agent strategy. One angle for future research is the suggestion of additional frameworks based on the multi-agent approach.

Electrical stations (substations) represent basic subsystems of the power grid, being required to establish their modes of operation, evaluation and modelling in order to set a degree of continuity in electric energy supply of load points or consumers. Adoption of optimal solutions of supply in supply with electrical energy of industrial consumers is a very complex problem which involves analyses of a very large number of restrictions and factors, with quasi-determinate and aleatory characteristics. This paper presents a method for determining the optimal apparent power of electric transformers, respective the optimal demand coefficient in the first year of exploitation using the economic criteria and the Matlab –Simulink program.

This study is a narrative review that aimed at exploring the benefits, risks, and policy controls of Bring Your Own Device (BYOD) for maximum and effective BYOD adoption. BYOD is a paradigm where employees use their personal devices such as Smartphones, tablets, laptops, etc., to access organizations’ enterprise resources such as email, file servers, and database contents and networks. Significant empirical evidence from literature revealed that 82% of organizations have a BYOD program, while 68% of organizations see a jump in productivity after switching to BYOD. Despite these important virtues, numerous investigations have shown that threats and attacks on organization data and resources: confidentiality, integrity, and availability are the greatest security concern in BYOD environment. In this study, the authors adopted a narrative review methodology. A search, using keywords, was conducted and fifty-five peer-reviewed journal papers within the last 5 years of this study were identified. These journals came from Pro Quest databases, ScienceDirect, Taylor and Francis, Crossref.com, Walden University collection of scholarly and peer-reviewed journals, and other related texts. Inclusion and exclusion criteria were applied, followed by a quality appraisal of the selected articles, before data were extracted.  Results show that good BYOD policies, guidelines, and practices coupled with good controls and management may avert security breaches on employees' and organizations' devices and resources. Results also show that it is possible to use machine learning approaches to handle threats and attacks such as persistent threats, data leakage, and data theft, denial of service (DOS) attack, intrusion attack, and untrusted network in BYOD environment. Findings may positively impact and equip organizations and employees with proven information for successful security and risk management programs that may increase mutual trust and a healthy BYOD adoption environment.