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Heavy metal contaminants in the soil will have a direct effect on human life. The spatial distribution of naturally occurring heavy metals is highly heterogeneous and significantly increased concentrations may be present in the soil at certain locations. Heavy metals in areas of high concentration can be distributed to other areas by surface runoff, groundwater flow, weathering and atmospheric cycles (eg wind, sea salt spray, volcanic eruptions, deposition by rivers). More and more people are now using a combination of geographic information science (GIS) with geostatistical statistical analysis techniques to examine the spatial distribution of heavy metals in soils on a regional scale. The most widely used geostatistical methods are the Inverse Distance Weighted, Kriging, and Spatial Autocorrelation methods as well as other methods. This review paper will explain clearly the source of the presence of heavy metals in soil, geostatistical methods that are often used, as well as case studies on the use of geostatistics for the distribution of heavy metals. The use of geostatistical models allows us to accurately assess the relationship between the spatial distribution of heavy metals and other parameters in a map.

"Caputo fractional differential equations with impulses are a very useful apparatus for adequate modeling of the dynamics of many rea world problems. It requires developments of good and consistent theoretical proofs and the results for various problems. In this note we point out and correct the statement of the boundary value problem with Riemann--Liouville fractional integral for impulsive Caputo fractional differential equation studied in the paper "" A. Zada, B. Dayyan, Stability analysis for a class of implicit fractional differential equations with instantaneous impulses and Riemann--Liouville boundary conditions, Ann. Univ. Craiova, Math. Comput. Sci. Ser., 47 (2020), 88-110."""

Based on the diazotization-coupling reaction, a new, simple, and sensitive spectrophotometric method for determining of a trace amount of (BPF) is presented in this paper. Diazotized metoclopramide reagent react with bisphenol F produces an orange azo-compound with a maximum absorbance at 461 nm in alkaline solution. The experimental parameters were optimized such as type of alkaline medium, concentration of NaOH, diazotized metoclopramide amount, order additions, reaction time, temperature, and effect of organic solvents to achieve the optimal performance for the proposed method. The absorbance increased linearly with increasing bisphenol F concentration in the range of 0.5-10 μg mL-1 under ideal conditions, with a correlation coefficient of 0.9931 and a detection limit of 0.15 μg mL-1. The effect of different temperatures and different extraction time was studied on the leaching out and the data indicates that as time and temperature rising, the concentration of BPF leached out of all thermal papers increased. To confirm that extracts from thermal papers contained BPF, samples containing the analytic were subjected to high-performance liquid chromatography (HPLC-UV detector) analysis. The analysis was carried out on a C18 column with a mobile phase of acetonitrile/water (55/45v:v), and the detection was conducted spectrophotometrically at 230 nm. The retention time of standard BPF was determined to be 5.649 min and the peak eluting time for most thermal papers extract was at 5.6 minutes, demonstrating that BPF was present in the thermal papers. The method was applied to quantify the proposed analyses in a variety of samples with excellent results.

One of the important keys for businesses today to be able to compete is to strengthen their supply chain management system.The impact of a pandemic is felt by all types of businesses, the most important unit of business that also feels the impact of the pandemic is how businesses maintain and even improve the performance of their supply chain management and one of the businesses or industries that is sufficiently affected by the pandemic for its supply chain resilience ispulp and paperindustry. The purpose of this study is to improve the performance of the supply chain, especially in the pulp and paper industry in Indonesia during the pandemic. This study uses two independent variables, namely inventory policies and information sharing and one dependent variable, namely supply chain performance. Data collection in the form of a survey using questionnaire media was carried out on 85 practitioners who work in supply chain units such as production, marketing and logistics. Data collection was carried out from July to September 2020. The results of this study are the conclusion that there is a positive and significant effect of inventory policies and information sharing on supply chain performance. The estimated coefficient of inventory policy on supply chain performance is 0.61, while the estimated coefficient of information sharing on supply chain performance is 0.24. The simultaneously effect of the two independent variables on the dependent is 0.72.

In this paper we will discuss about the Automatic sun tracking system which we will implement on metal detectionaobotic system, where robotic spontaneous sun tracing system is a hybrid hardware/software prototype, whichautomatically furnish best positioningof panelwith the sunlight to get maximal electric charge generation through solar panel. It’s active sensors continuously observed the monochromaticrays of sun and spin the panel about the direction where the potential of sun rays is maximal. A micro-controller works on automatic sun tracing deviceconnected with the new solar power transformunit is developed & execute. The automatic sun tracker is executed with a DC motor and a DC Motor controller. The conditions of the hardware subjected to the changes of the environmental conditions. In the new unit of the MAXIMUM POWER POINT is resolved to easy insertion software with a present sweep perspective, with this new perspective the standardization of the transform from solar energy to electric energy at its maximal power point can be develops extra definitive and extra authentication.

Nowadays, ports are in need to maximize their incomes, and this based on the fierce competition. For this reason, all ports stakeholders should be involved to contribute in the design and the development of a policy of scheduling and priority.This project owned by the Vessel Call Service Planning Service in the port of Tanger Med as the "Tanger Med Port Authority", and it output was to report the summarized the work done and the methods behind it.The main goal is to develop a simulator model that includes all kind of operations and the operational process by choosing the appropriate KPIs that are fully reflecting the congestion transferred by port vesselsFirst, it aims to define the operating assumptions and the fundamental concepts on which our simulation model will be based and to present the data that were used for the implementation of the simulation as well as the origin of these data.Secondly, it aims to validate and calibrate the model by presenting some improvements that could be made to the simulator in order to make it more precise and more representative and to ensure automation of the processing of inputs and outputs. While towards the end we conclude with the presentation of congestion situations, the results obtained and their use in decision making.AIS data is another factor has been added to help in getting best results, this helped in vessels planification in/out predictive process while automating the use of our simulator with the AIS Data receipt from SatelliteThis part of project is in to give the smart aspect to our simulator results by using smart technology.

In the article discussed history of building Astrakhan and Selenga paper and cardboard mills. The author on base archival materials is analyzing the impact of expert commentary on the building paper and cardboard mills. The main purpose of the article is to show, on the example of the construction of the CCC, the process of relations between scientific expert groups and government representatives on the issue of environmental safety in the design and location of the country's production facilities. In addition, the author emphasizes that for the Soviet leadership, issues of the environmental component of enterprises often became secondary, departing from economic necessity. At the same time, the scientific community itself did not in some cases have a single position on a particular issue, since a conflict arose between representatives of departmental and scientific academic structures, which was most pronounced during the construction of the Selenginsky pulp and cardboard plant. In the case of the Astrakhan pulp and cardboard plant project, it is shown that underestimating the capabilities of the resource base of production can lead to environmental problems. Author marked that despite of scientific and technological inspection, scientific opinions was ignored by government leaders in cases large technological objects.

This paper presents a comprehensive study and analysis of the intelligent grouping of papers in adult higher education using a random matrix approach. Using the results of random matrix theory on the eigenvalues of the sample covariance matrix, the energy of each subspace is estimated, and the estimated energy is then used to construct a subspace weighting matrix. The statistical properties of the sample covariance matrix eigenvectors are analyzed using the first-order perturbation approximation, and then, asymptotic results from random matrix theory on the projection of the sample covariance matrix signal subspace to the real signal parametrization are used to obtain the weighting matrix based on the random matrix eigenvectors. Dynamic adjustment according to the fitness of individuals in the population is performed to ensure population diversity, while the combination of the small habitat technique can avoid the algorithm from falling into early convergence. The algorithm introduces chaos theory to optimize the population initialization process and uses the dynamic traversal randomness of chaos to select individuals in the population so that the initial population is close to the desired target solution. The design of the fitness function in the genetic algorithm generally maps the objective function of the problem to the fitness function. A good fitness function can directly reflect the quality of the individuals in the group. Based on the in-depth study of the basic attributes of the test questions and the principles of test paper evaluation, the mathematical model and objective function of intelligent paper grouping are determined by the difficulty, knowledge points, and cognitive level of the test questions as the main constraints, and NCAGA is applied to the intelligent paper grouping method, which better completes the intelligent paper grouping session for the computer system architecture course. In the process of designing the intelligent grouping algorithm, for the situations of premature convergence and convergence to locally optimal solutions that easily occur in the traditional genetic algorithm, this paper adopts the approach of adaptive adjustment of crossover probability and variation probability to improve the algorithm and achieves satisfactory results. Based on extensive business research, this paper completes the requirement analysis of the online practice system based on the intelligent grouping of papers and presents the functional design and database design of the key functional modules in the system in detail. Finally, this paper conducts functional tests on the system and analyses the test results.

This editorial is a short review of papers accepted in the Mathematics and Symmetry/Asymmetry section in 2020–2021 about the symmetry methods [...]

This issue of featured papers from 2020 is related to the study of symmetry phenomena in various different fields, but mainly in theoretical physics [...]

Two quantitative, environment-friendly and easily monitored assays for Ni (II) and Co (III) ions analysis in different lipstick samples collected from 500-Iraqi dinars stores located in Baghdad were introduced. The study was based on the reaction of nickel (II) ions with dimethylglyoxime (DMG) reagent and the reaction of cobalt (III) ions with 1-nitroso-2-naphthol (NN) reagent to produce colored products. The color change was measured by spectrophotometric method at 565 nm and 430 nm for Ni and Co, respectively, with linear calibration graphs in the concentration range 0.25-100 mg L-1 (Ni) and 0.5-100 mg L-1 (Co) and LOD and LOQ of 0.11 mg L-1 and 0.36 mg L-1 (Ni), and 0.15 mg L-1 and 0.49 mg L-1 (Co). The UV/VIS data was compared to the results obtained by a novel microfluidic paper-based analytical device (µPAD) platform offering in-situ and cost-effect assay with a similar calibration graph with LOD and LOQ of 0.21 mg L-1 and 0.70 mg L-1 (Ni), and 0.22 mg L-1 and 0.75 mg L-1 (Co). The analysis of variance (ANOVA) indicated no significant difference between the UV/VIS, µPAD, and standard atomic absorption spectrometry (AAS) assay Ftab= 3.46 is much higher than FStat = 0.13 (Ni) and Ftab= 3.46 is much higher than FStat = 0.02 (Co). Also, a good correlation between results via the three methods was found. Thus, the µPAD platform offers a solid base for providing valuable information outside centralized laboratories.

Very recently, I. Altun, M. Aslantas and H. Sahin [1] introduced the notion of $$p$$ -proximal contractions and surveyed the existence of best proximity points for such class of non-self mappings in metric spaces. In this note we show that this existence result is a straightforward consequence of the same conclusion in fixed point theory.

Traffic boards and traffic signals are used to maintain proper traffic through busy roads. They help to recognize the rules to follow when driving the vehicle. These signs warn the distracted driver, and prevent his/her actions which could lead to an accident. We have proposed a system which can help recognize these boards and signals at real time thus avoiding major mishap. A real-time automatic sign detection and recognition can help the driver, significantly increasing his/her safety. Lately traffic sign recognition has got an immense interest lately by large scale companies such as Google, Apple and Volkswagen etc. which is driven by the market needs for intelligent applications such as autonomous driving, driver assistance systems (ADAS), mobile mapping, Mobil eye, Apple, etc. Hence, here, we have implemented to do the same with cost efficient manner using Raspberry Pi. The proposed system detects the traffic board or traffic signals, capture its image which through deep learning approach recognizes the same to give result on dashboard as well it gives the measures of distance from front obstacle which helps to implement brake system if obstacle is near. PiCam is used to capture images of traffic sings and is connected to RaspberryPi. Monitor is used to display required output, showing type of sign and distance of collision. This proposal will avoid large number of accidents occurring at bridges and work in progress area due to automated braking system and simultaneous reduce death ratio.

This is a corrigendum to our paper, “On a class of prime entire functions”, published in Acta Math. Sin., Engl. Ser., 25, 1647–1652 (2009).

Erratum to the paper [Konovalov, Alexander; Smoktunowicz, Agata; Vendramin, Leandro. On skew braces and their ideals. Exp. Math. 30 (2021), no. 1, 95–104. DOI: 10.1080/10586458.2018.1492476.].

This Special issue contains top-tier physics-related and mathematical research, among other topics, written by scholars who are well-known in their field [...]

Sendov’s conjecture states that if all the zeroes of a complex polynomial P(z) of degree at least two lie in the unit disk, then within a unit distance of each zero lies a critical point of P(z). In a paper that appeared in 2014, Degot proved that, for each a ∈ (0, 1), there exists an integer N such that for any polynomial P(z) with degree greater than N, if P(a) = 0 and all zeroes lie inside the unit disk, the disk |z − a| ≤ 1 contains a critical point of P(z). Based on this result, we derive an explicit formula N(a) for each a ∈ (0, 1) and, consequently obtain a uniform bound N for all a ∈ [α, β] where 0 < α < β < 1. This (partially) addresses the questions posed in Degot’s paper.

Undergraduate research increasingly features in university mathematics degrees. Despite this, research papers are used infrequently in mathematics teaching, and this is especially the case for first-year undergraduates. Mathematical subjects are more likely than other STEM disciplines to pinpoint cognitive difficulty as the principal reason for not exposing undergraduate students to research papers. In this paper, we test whether first-year students can engage effectively with research papers. We describe an intervention that exposes first-year, first term undergraduate students to current research in probability and statistics by asking them to read a research paper and summarize it for a general readership following an interview with the paper’s author. Our findings show that the activity introduced students to new fields of knowledge and helped to develop a clearer understanding of scientific process, leading to a heightened sense of personal satisfaction at engaging closely with current research. We argue that structured reading of research papers can lead to productive and rewarding engagement with difficult content, recent and current research and with research processes and that this should make us reconsider the role of research papers in the undergraduate mathematics curriculum.

Even fairly good students, when they have obtained the solution of the problem and written down neatly the argument, shut their books and look for something else. Doing so, they miss an important a...

Organisms may respond to local stimuli that benefit or threaten their fitness. The adaptive movement behaviour may allow individuals to adjust their speed to maximise the chances of being in comfort zones, where death risk is minimal. We investigate spatial cyclic models where the rock-paper-scissors game rules describe the nonhierarchical dominance. We assume that organisms of one out of the species can control the mobility rate in response to the information obtained from scanning the environment. Running a series of stochastic simulations, we quantify the effects of the movement strategy on the spatial patterns and population dynamics. Our findings show that the ability to change mobility to adapt to environmental clues is not reflected in an advantage in cyclic spatial games. The adaptive movement provokes a delay in the spatial domains occupied by the species in the spiral waves, making the group more vulnerable to the advance of the dominant species and less efficient in taking territory from the dominated species. Our outcomes also show that the effects of adaptive movement behaviour accentuate whether most individuals have a long-range neighbourhood perception. Our results may be helpful for biologists and data scientists to comprehend the dynamics of ecosystems where adaptive processes are fundamental., Comment: 8 pages, 7 figures