Additional Problems Research Articles

Extending access for all chemistry students with extended reality

Equal access to instructor’s time and attention in chemistry classes and laboratories can be a barrier experienced by students from historically excluded groups. An instructor’s own biases will determine the nature of their interaction with students, and even well-meaning instructors can interact with students in slightly different ways, which might prevent certain students from having access to all the available instructional resources for the class. This is an additive problem, which may or may not be recognized in peer and student evaluations, and an issue that might escape self-reflection even in educators that are committed to diversity, inclusion, and justice. This issue conflates both actual and perceived biases, introducing a complex dynamic between instructor and student. Extended reality (XR) provides an avenue to generate materials that can be used to enhance or replace classroom instruction with a great degree of realism. In this paper we will discuss the implementation of a set of virtual reality (VR) organic chemistry labs. We will show that XR learning tools are by their very nature accessible and inclusive of a wide variety of students and will provide evidence from student reflections that shows that students from historically excluded groups find the XR content offered in our virtual reality labs more personal than in-person activities covering the same material.

Phase synthesis method in multi-aperture optical systems based on iterative image processing algorithms

Background. Modern technologies in the field of optics and photonics place high demands on the quality and output power of the radiation source. The fulfillment of these requirements can currently be achieved by creating multi-aperture laser systems with coherent beam addition. The main problem of creating such systems is the development of phase synthesis methods in a multichannel optical system. Aim. In this paper, we consider a phase synchronization method without a reference beam for a coherent addition system with active feedback, which is based on the Gerchberg–Saxton algorithm. This algorithm makes it possible to reconstruct complex field amplitudes in the aperture and focal planes from intensity distributions in these fields. The application of this algorithm for multichannel systems is analyzed and its features, such as the occurrence of stagnation and ambiguity of the solution, are revealed. Methods. Solutions are proposed to eliminate the problem of convergence of the algorithm to side solutions and getting the iterative procedure into the local extremum using global optimization algorithms, methods of reducing the dimension of the problem and the introduction of antisymmetric amplitude modulation. Results. The paper demonstrates the results of phase field reconstruction for a large number of optical sources. For a seven-aperture system, a physical simulation was performed to restore phase information, confirming the results of numerical modeling. Conclusion. The proposed approach is a reasonable alternative to currently existing methods and can be used in the problem of coherent addition in multichannel optical systems.

Efficient photocatalytic in-situ Fenton degradation of 2,4-dichlorophenol via anthraquinone-modified carbon nitride for 2e− oxygen reduction

Constructing a photocatalytic in-situ Fenton system (PISFs) is a promising strategy to address the need for continuous hydrogen peroxide (H2O2) addition and the low efficiency of H2O2 activation for hydroxyl radical generation in the traditional Fenton reaction. In this study, we constructed a photocatalytic in-situ Fenton system using anthraquinone-modified carbon nitride (AQ-C3N4) for efficient pollutant degradation. The resultant AQ-C3N4 not only enhanced the production of H2O2 but also increased the generation of hydroxyl radical (·OH). Experimental results demonstrated that, the apparent rate constant for the degradation of 2,4-Dichlorophenol (2,4-DCP) by AQ-C3N4-PISFs was 0.145 min−1, which is 2.74 times higher than that of C3N4 under visible light. Density functional theory (DFT) calculations indicate that AQ modification promotes electron-hole separation while increasing the adsorption energy of O2. Independent gradient model (IGM) analysis based on Hirshfeld Partition revealed that van der Waals interactions between AQ-C3N4 and 2,4-DCP promoted the degradation process. This work provides new ideas to overcome the problems of continuous addition of H2O2 and low utilization of ·OH that exist in conventional Fenton system.

Strassen's rank additivity for small tensors, including tensors of rank less or equal 7

The article is concerned with the problem of additivity of the tensor rank. That is, for two independent tensors, we study when the rank of their direct sum is equal to the sum of their individual ranks. The statement saying that additivity always holds was previously known as Strassen's conjecture (1969) until Shitov proposed counterexamples (2019). They are not explicit and only known to exist asymptotically for very large tensor spaces. In this article, we present families of pairs of small three-way tensors for which the additivity holds. For instance, over the base field C, it is the case if both tensors are of rank less or equal 7. This proves that a pair of 2×2 matrix multiplication tensors has the rank additivity property. We show also that the Alexeev-Forbes-Tsimerman substitution method preserves the structure of a direct sum of tensors.

An additive problem over intersection of two Piatetski–Shapiro prime sets and almost-primes

An additive problem over intersection of two Piatetski–Shapiro prime sets and almost-primes

Reduction procedure for obtaining solutions of the scalar additive Jump problem and Riemann boundary value problem in vectorial Clifford analysis

In this paper, we study existence of solutions to the scalar additive Jump problem and the Riemann boundary value problems in the context of vectorial Clifford analysis on domains with fractal boundaries. A reduction procedure is applied with great effectiveness to find the solution of the problems.

The Effectiveness of Alternative Tools for Measuring Metacognitive Skills in Terms of the Multi Methods Design

The study aimed at reaching a valid methodology to measure metacognition through alternative tools constructed and validated in terms of multi-method design that combines between qualitative and quantitative methods in measurement. A pilot study was conducted in which the computerized problem solving test was applied on sample of undergraduate students, the qualitative and quantitative data concerning their methods and paths they used to solve the problem in addition their thinking aloud protocols were collected, These data are used in preparing the study tools that applied on a sample consisted of (110) students from the faculty of education in(2013/2014). The study revealed that there was a statistically significant correlation between students' scores in the concurrent methods (TAP) and the offline methods "MRT", "TSQ", The skills measured by the multiple response test were the most contributors to interpreting and predicting performance. The study revealed also that students' post calibration scores was a good indicator of metacognitive monitoring, and it was more accurate than pre calibration for high performing students. Traces data presented valuable information about students' skills and activity at each step of the solution.

Isolation, and Identification of Escherichia coli O157:H7 Recovered from Chicken Meat at Addis Ababa Slaughterhouses.

It is a growing concern that pathogenic bacteria can be found in poultry meat, and an additional problem is the ongoing rise in food-derived bacteria's resistance to antibiotics. A cross-sectional study was conducted from February 2021 to March 2023. This study aimed to isolate, identify and analyze E. coli in poultry meat collected from slaughterhouses in Addis Ababa. A total of 499 samples were collected from fecal content, carcass, hand and knife swab samples by using purposive and systematic random sampling methods. An overall 5.2% Escherichia coli (E. coli O157:H7) prevalence was found in this study. On average, antimicrobial susceptibility tests revealed that the sensitivities of (Escherichia coli) E. coli O157:H7 isolates from carcass swabs, fecal content, manuals, knife swabs and water samples were 62.3%, 52.5%, 53%, 60% and 60%, respectively. However, few (Escherichia coli) E. coli O157:H7 isolates have developed multidrug resistance to some antibiotics, for an overall rate of 13.8%. Knowledge and attitude assessment of the slaughterhouse workers showed that 44.2% had no wash their hands at all and that 125.6% had washed their hands before slaughter commencement. The detection of (Escherichia coli) E. coli O157:H7 isolates from all sample types had a slight prevalence of serious public health concerns. It is important to monitor antibiotic use for both human and animal health in order to make sure that it is safe and effective.

Robot Ethics

Robot Ethics

Enhancing inconsistent language problem-solving in an autistic student through a modified schema-based instruction

ABSTRACT This study evaluates the effectiveness of Modified Schema-Based Instruction (MSBI) and instructor support in enhancing mathematical problem-solving skills in a child with autism (ASD), focusing particularly on inconsistent language problems. We conducted a single-case analysis in Spain involving a 6-year-old participant, Sam, exploring his responses to different additive comparison problems, based on a structured instructional approach. Results indicate significant improvement in Sam's ability to understand and solve inconsistent language problems, demonstrating the potential of MSBI in educational settings for autistic children. This research contributes valuable insights into tailored instructional strategies that can aid in overcoming specific learning challenges faced by autistic students.

Incidental gall bladder carcinoma after cholecystectomy for benign disease: An institutional experience

Cholecystectomy is the most common routinely performed procedure for benign gallbladder disease worldwide and incidental gall bladder cancer is mostly detected in post-cholecystectomy specimens.This retrospective study emphasizes on the need for routine surveillance of post-cholecystectomy specimens by evaluating the incidence of incidental findings of carcinoma in cholecystectomy specimens done for benign gallbladder disease.A total of 2443 patients were evaluated over a period of 7 years, out of which, 18 patients were diagnosed with incidental gall bladder carcinoma with an incidence of 0.73 %. The mean age of affected patients was 59 years. Among the 18 patients, 8 patients (44 %) had an intra-operative suspicion of malignancy. Once incidental cancer is detected the treatment decision should be decided according to tumor spread and depth as well as the patient's age, additional health problems, and life expectancy.

Ecocriminological analysis of brine in aquatic ecosystems: impacts on Posidonia oceanica and the search for restorative justice solutions.

The consumption of fresh water has generated additional problems in certain territories, along with the consequences of global warming. This has meant that in the most vulnerable areas, such as the Balearic archipelago in the Mediterranean, alternative water supply systems have been established: desalination plants. However, the ecological impact of these infrastructures is great, mainly affecting aquatic ecosystems. In light of the above, this paper addresses the ecological harm caused by desalination and brine discharges on a protected and priority species, P. Oceanica. Taking as ethico-legal foundation the theory of ecological justice, a multilevel analysis was carried out from an ecocriminology perspective on the impacts of this authorized practice on P. Oceanica and other species. Finally, a restorative justice view will allow us to understand and envision possible solutions to this ecological harm.

РАСПРОСТРАНЕННОСТЬ КАРИЕСА ЗУБОВ И ЗАБОЛЕВАНИЙ ПАРОДОНТА У ДЕТЕЙ С НАРУШЕНИЕМ СЛУХА (ОБЗОР ЛИТЕРАТУРЫ)

Subject. Deafness, hearing loss are one of the most common sensory pathologies in children. It negatively affects the formation of personality and quality of life. Children with hearing and speech impairments require special medical supervision. It is necessary to develop programs to prevent major dental diseases for deaf children. This requires a comprehensive assessment of the dental status, taking into account age, the severity of the main pathology, and socio-psychological factors that contribute to the development of the formation characteristics of the child’s body.
 Purpose. To analyze the prevalence and intensity of dental caries and periodontal diseases in children with hearing impairment according to various literature data.
 Methodology. An analysis of publications was carried out using scientific search library databases: PubMed Central, Google, Medline, eLibrary. The selection of materials was based on using keywords. The search included full-text articles. 36 sources were analyzed.
 Results. Analysis of the prevalence of dental diseases in children with hearing impairment has not been sufficiently published in Russian-language literary sources.
 According to various literature data, there is a high prevalence of caries and periodontal diseases in children with hearing impairment. Some authors compared these indicators with a group of healthy children. Children with hearing and speech impairments have higher rates of prevalence and intensity of caries and periodontal diseases.
 Conclusions. The high prevalence of dental diseases in children with hearing impairment is an additional medical and social problem. For this category of the population, it is of great importance for the development of prevention programs.

Solution strategy for sustainable additive manufacturing design problem using Pythagorean fuzzy MCGDM methodology

To solve difficulties involving various groups’ decision-making problems, this work has been proposed to develop a logical aggregation approach to aggregate decision-makers’ crisp data into Pythagorean fuzzy numbers. By combining the established strategy with the Pythagorean fuzzy TOPSIS method, a hybrid Pythagorean fuzzy multiple criteria group decision-making methodology is presented. Based on fuzzy rules inference and the Takagi–Sugeno technique, a novel function is created to represent the degrees of uncertainty in decision-makers’ data. As an example, the material selection process in practical additive manufacturing designs is provided to show how the proposed methodology may be applied to actual applications. Sensitivity analysis is used to evaluate the effectiveness of the suggested methodology. The outcomes demonstrate that the plan was successful in producing a PFN that accurately reflects the decision-maker’s knowledge.

Applying Problem Solving Approach in Teaching Addition and Subtraction Word Problems in Diverse Grade 3 Classrooms

Word problem solving is an approach that can increase knowledge, improve performance and develop learners’ critical thinking skills that can assist them in solving mathematical and real-life problems. This study examined the effectiveness of using a word problem solving approach to improve Grade 3 learners’ performance when learning addition and subtraction. The study employed this hypothesis to test the difference between the experimental and control groups and between the pre-test and post-test with learners in diverse classrooms solving addition and subtraction word problems. A pre-test-intervention-post-test research design was used to collect the data. Baseline lesson observations and unstructured interviews were conducted to understand the effectiveness of the problem solving approach in teaching number concepts, problems, addition and subtraction. The results of the study revealed a significant difference between the experimental and comparison groups when solving addition and subtraction word problems. Furthermore, there was a significant difference between the pre-test and the post-test in the experimental group. It was concluded that word problems could be taught by following steps for problem solving and equipping learners with essential reading skills to help them comprehend what they are reading. The interviews showed that teachers do not have enough time for learners who experience learning challenges and reading in particular in pursuit of covering the curriculum. Learners in the foundation phase must be taught money problems and problem-solving skills to acquire knowledge to be used in higher grades and real-life situations.

Process implications on the stability and reliability of 300 mm FAB MoS2 field-effect transistors

Recent advances in fabricating field-effect transistors with MoS2 and other related two-dimensional (2D) semiconductors have inspired the industry to begin with the integration of these emerging technologies into FAB-compatible process flows. Just like in the lab research on 2D devices performed in the last decade, focus during development is typically put on pure technology-related issues, such as low-temperature growth methods of large-area 2D films on target substrates, damage-free transfer from sacrificial substrates and growth of top-gate oxides. With maturing technology, the problem of stability limitations caused by oxide traps is gradually coming into focus now. Thus, here we report an in-depth analysis of hysteresis and bias-temperature instabilities for MoS2 FETs fabricated using a 300 mm FAB-compatible process. By performing a comprehensive statistical analysis on devices with top gate lengths ranging between 18 nm and 10 μm, we demonstrate that aggressive scaling results in additional stability problems, likely caused by defective edges of the scaled top gates, in particular at higher operation temperatures. These are important insights for understanding and addressing the stability limitations in future nanoscale 2D FETs produced using FAB process lines.

Enantioselective recognition, synthesis, and separation of pharmaceutical compounds at chiral metallic surfaces.

The development of new pharmaceutical compounds is challenging because most of them are based on enantiopure chiral molecules, which exhibit unique properties for therapy. However, the synthesis of pharmaceutical compounds in the absence of a chiral environment naturally leads to a racemic mixture. Thus, to control their synthesis, an asymmetric environment is required, and chiral homogeneous catalysts are typically used to synthesize enantiopure pharmaceutical compounds (EPC). Nevertheless, homogeneous catalysts are difficult to recover after the reaction, generating additional problems and costs in practical processes. Thus, the development of chiral heterogeneous catalysts is a timely topic. In a more general context, such chiral materials cannot only be used for synthesis, but also to recognize and separate enantiomers. In the frame of these different challenges, we give in this review a short introduction to strategies to extrinsically and intrinsically modify heterogeneous metal matrixes for the enantioselective synthesis, recognition, and separation of chiral pharmaceutical compounds.

Algorithm for improving the quality of mixed noisy images

Digital images are one of the effective means of receiving, transmitting, exchanging and expressing information. However, the digital image is not always of the expected quality, that is, as a result of the influence of various factors, noises appear in the image. This significantly reduces the accuracy and quality of the data in the image. Segmentation and recognition of objects from a low-quality image creates many additional problems. For example, it requires image quality enhancement based on powerful pre-processing algorithms. One such problem is to eliminate multiple noises in the image, and it is one of the pressing issues of digital image processing. This paper is devoted to solving the problem of image reconstruction by eliminating the mixed condition of Gaussian, salt-pepper and Poisson noises, which are common in digital images, in which one filter that optimally reduces each type of noise is selected and all combinations of them are applied to the mixed noise image to maximize the images. The idea of restoration has been put forward. The quality of the reconstructed images was evaluated by the NIQE criterion, which is one of the no-reference quality indicators, and a rule for automating the image processing process was proposed based on its values.

Nongradient-Based Tracking of Environmental Field Isolines in a Changing Medium by Dubins-Vehicle Type Robots

A non-holonomic robot of a Dubins-vehicle type moves in a changing resistant medium, like water or air. The objective is to exhibit the extension of a spatial phenomenon (e.g., a critically contaminated area) related to a dynamic environmental field (e.g., a distribution of the contaminant concentration). Specifically, the robot should arrive at a certain level set of the field and repeatedly sweep it afterwards. The field data comes exclusively from online and point-wise measurements of the field value at the current location of the robot. An additional problem is related to the significant uncertainty on the field and the medium, including their variation with time and the effect of the medium on the robot's motion. The conditions for the accomplishability of the mission objective are found under these uncertainties and constraints on the kinematics of the robot. A navigation algorithm is presented that solves the mission with a slight enhancement of these necessary conditions. The performance of the algorithm is rigorously justified by the non-local convergence result and validated by computer simulation tests with a 6-DOF catamaran-like vessel and real-world environmental data.

Public Voices in the Environmental Decision-Making in Georgia

The article presents the results of the scientific research and gives the ways to solve the problems dedicated to PP (public participation) in the process of EDM (environmental decision-making) in Georgia. Several obstacles were found, by studying the environmental non-governmental organizations (NGOs) in Georgia. All necessary information was collected through interviews and questionnaires. The study discusses the existing legislation on this issue and aims to find answers to these obstacles. Four hypotheses were developed - transparency in the decision-making process promotes successful public participation, effective cooperation with one another is a better way for NGOs to participate in the environmental decision-making process, Georgian NGO’s successful participation in the process of DM (decision-making) was related to the development of an environmental legal system, self-financing helps the Environmental NGOs in Georgia to improve their financial status and increase their flexibility in the EDM process. The Soviet regime caused the nonexistence of PP approaches in EDM. Currently, many international and trans-boundary projects are taking place and will be completed shortly in Georgia. The participation of the public, especially non-governmental organizations is a key point and crucial element in decision making as most of these developments entail additional environmental problems and to prevent damage to the environment and foster sustainable development when such projects are completed. The research gives key provisions that require improvement to increase the effectiveness of PP in EDM process.
 Keywords: public participation, environment, decision-making, NGOs