Scientific Calculator Research Articles

Sensitivity, Specificity and Predictive Values of Chest Indrawing in the Diagnosis of Severe Pneumonia

Background: Pneumonia is a recognized leading killer disease in under 5 children not only in Bangladesh but also in all developing countries. The presence of lower chest indrawing means that the child has severe pneumonia. This study aimed to determine the sensitivity, specificity and predictive values of chest indrawing in the diagnosis of severe pneumonia. Methods: This analytical study was conducted in the department of pediatrics, Sher-e-Bangla Medical College Hospital, Barisal, from January 2015 to December 2015. A total of 100 cases of severe pneumonia aged from 2 months to 5 years and similar numbers of suitably matched controls who fulfilled inclusion criteria were enrolled in this study. A detailed history was taken, a thorough physical examination was done, data were recorded in a preformed questionnaire and were analyzed using a scientific calculator. Results: Out of 100 cases, 80 (80%) and 100 controls, 72 (72%) were in the age group of 2 months to 1 year. Fast breathing was present in 98 (98%) cases and 88 (88%) controls. Chest indrawing was present in 56 (56%) cases and 42 (42%) controls. Roentgenographically, 44 (44%) cases revealed labor/segmental consolidation, and bilateral patchy consolidation was present in 56 (56%) cases. Among the control group, 28 (28%) patients had hyperlucency of peripheral lung fields in their chest X-rays. In this study, it was found that sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of chest indrawing in the diagnosis of severe pneumonia was 56%, 58%, 57.1% and 56.8% respectively. Conclusion: Chest indrawing alone is not a highly sensitive tool to predict severe pneumonia but in rural areas where X-ray facilities are not available, chest indrawing may play an important role in identifying children with possible severe pneumonia. Mediscope 2022;9(2): 54-59

Flowing water-based tubular triboelectric nanogenerators for sustainable green energy harvesting

The green energy present in flowing water is underused owing to lack of environmentally acceptable and sustainable energy harvesting technologies. The triboelectric nanogenerators (TENGs) have received significant attention as a prospective technological advancement due to their simple structure and multiple working modes. Among them, the single electrode mode TENGs with no moving parts could facilitate the development of innovative sustainable energy harvesting technologies. Here, a polytetrafluoroethylene (PTFE)-copper (PC-TENG) tube with single electrode mode is developed for harvesting flowing water energy. Using tap water as a source, the PC-TENG tube, with a length of 40 cm and a diameter of 10 mm achieves a maximum power of 45 µW at a load resistance (RL) of 5 MΩ. The sustainable power generation is demonstrated by powering light emitting diodes (LEDs) and a scientific calculator with tap water flowing at a rate of 2.5 L min−1. Finally, the practical feasibilities of the proposed PC-TENG are demonstrated as self-powered sensor in two biomedical applications such as continuous wireless monitoring of IV drips injection, cardiac cycle and heart rate using a phantom. This work has great potential for the development of single electrode TENGs for continuous power generation and self-powered sensor applications.

Simplified Voltage-Power Formula를 이용한 방사상 배전선로의 Step-by-Step 전압계산

For a distribution power system, the loads are represented by kVA or P+jQ form in general. The so-called V-P formula(=Voltage-Power formula) composed of bus voltages and load power P,Q has been announced in recent publications. This paper introduces a step-by-step voltage calculation of each load point for a radial distribution power system using the simplified V-P formula without solving a simultaneous equation. Since each simplified V-P formula has at most two voltage variables, the voltages of load points can be obtained by the step-by-step method using a scientific calculator. The authors illustrate an example calculation for a distribution line with three P-Q load points to compare with the power flow computation. Calculation result by the proposed step-by-step method using simplified V-P formula has shown an acceptable error rate for use in the industrial fields.

P-Q 부하가 주어진 배전선로 두 부하점의 약식(略式) 전압계산 - Simplified Voltage-Power Formula를 이용한 배전선로의 전압계산 -

For a distribution power system, the load connected to a load point is represented by kVA or P+jQ form in general. The so-called two-bus V-P formula(=Voltage-Power formula) composed of bus voltages and load power P,Q and a calculation example for load voltages in a distribution line with two P-Q load points have been presented in recent publications. While the result by conventional ‘Equivalent resistance method’ is approximate, the calculation using V-P formula has yielded an exact solution. However, the original V-P formula that includes the power line loss makes the equation much complicated to obtain solutions using a scientific calculator. This paper presents a new voltage calculation using the simplified V-P formula in which the line power loss is eliminated for calculation simplicity, and illustrates an example calculation for a distribution line with two P-Q load points to compare with existing methods. Calculation result by the proposed simplified V-P formula has shown an acceptable error rate for using in the industrial fields.

Simple and Accurate Approximation of Rough Conductor Surface Impedance

This article presents a simple but accurate approximation of the surface impedance of rough conductors. The approximation uses insights about properties of magnetic field and surface impedance observed from the finite-difference numerical solution of gradient model. The key insight is that surface impedance calculated by the gradient model is essentially only a function of frequency. This property allows the design of approximating function that depends only on frequency but can be used to calculate the surface impedance of conductors with any conductance and roughness. Coefficients for Gauss and Rayleigh distribution of position-dependent conductance are given, and approximations are compared to numerical solutions. The relative error of both approximations is below 0.1% at all frequencies of interest. Approximating function is causal by design and is simple enough that it could be evaluated with a scientific calculator.

Some Applications of Cubic Equations in Engineering

Cubic equations have many applications in engineering, three of them are discussed in this paper. There are many equations of states for real gases but the cubic equations are the simplest ones and are sufficiently accurate for a limited range of temperatures and pressures. Degree of dissociation of chemical equilibrium for carbon dioxide and water can be written as cubic equations. Slope of a simply supported beam loaded by a continuous load is also represented as a cubic equation. Cubic equations can be solved exactly using Cardano’s formula. They can also solve numerically; Newton-Raphson method is a popular choice. Although a cubic equation has three roots, only real roots are valid in real applications discussed in this paper. Even there may be only one root that can be used; two other roots will be discarded. There are many ways a cubic equation solved but the simplest one is to solve it manually using a scientific calculator. Software and programming languages are better if there are many equations to be solved repeatedly.

A look back at a long-forgotten trigonometric function: the versine function and its inverse

Ask anyone who has studied mathematics to a moderate level how many trigonometric functions there are and one is likely to be presented with a range of answers depending on what the person being asked is most likely to remember. Perhaps the ‘calculator button’ three of sine, cosine, and tangent will come to mind as these are the three trigonometric functions found on any standard scientific calculator. At a stretch, perhaps the names for their respective reciprocals, cosecant, secant and cotangent, will be recalled. Beyond the modern standard six, looking at calculus or trigonometric texts published prior to 1900 one soon discovers others going by strange names such as versine, haversine, or coversine (see, for example, [1, pp. 53, 63]). There are at least six others with as many as perhaps ten to twelve having received a name at one time or another. Today all these additional trigonometric functions considered important enough to grace the pages of texts in centuries past have fallen by the wayside, to be largely forgotten in favour of the modern standard six. Of course the pedant amongst us would say there is only one trigonometric function, the sine function, which currently stands as the preferred fundamental trigonometric entity, with all others being simple variations of this function, and they would not be incorrect in asserting this. But having the current standard six seems about the right balance between the minimalistic on the one hand and convenience on the other hand.

A fast and accurate way of evaluating the Widlar current using the Newton–Raphson method

The Widlar current source is one of the basic current sources that undergraduate students encounter throughout their learning process on electronics courses. The Widlar current is actually given in terms of a transcendental equation. Although an analytical solution exists in terms of the Lambert W function it might not be that useful for students during exams or other practical applications. This paper presents a fast and accurate way to solve the problem numerically using the Newton–Raphson method with a regular scientific calculator, and compares the results with the analytical solution given by the Lambert W function.

DETERMINATION OF SEXUAL DIMORPHISM USING NASAL AND FACIAL INDICES AMONG THE HAUSA ETHNIC IN NIGERIA

The purpose of this study was to identify sexual dimorphism among Hausa ethnic group students at a chosen higher educational institution in Kano using nasal and facial indices. 150 students between the ages of 18 and 30 were involved in the study—75 males and 75 females. The voluntarily recruited study subjects had no history of physical malformations, facial or nasal surgery, cleft lip or palate. Digital Vernier calliper, scientific calculator, weighing machine and sterilisation consumables were used for the study. The individual subjects were instructed to sit calmly, straighten out, and look forward. The nasal and facial index (NI) was measured and recorded during the facial anthropometry. According to the study, the mean age of the study sample for males’ students was 25.1 ± 3.60 years and for female students it was 23.4±3.10 years. Males and females differed significantly in terms of NI (P<0.001), height (P<0.05), and nasal width (P<0.001). Based on the Nasal Index and its distribution, the nasal shapes of the Hausa ethnic group were described as mesorrhine (66%), leptorrhine (29.3%), and platyrrhine (4.7%). It was also found that Nasal Index in males is higher than that of the females. This study demonstrates existence of sexual dimorphism in nasal and facial indices among Hausa ethnic group in Kano State, Nigeria

Research on cam frequency-increasing hybrid piezoelectric electromagnetic energy harvester with center symmetric structure

This paper proposes a cam frequency-increasing hybrid piezoelectric electromagnetic energy harvester with center symmetric structure (C-HEH). The use of the cam structure allows the harvester to increase the efficiency of energy harvester per unit time, while the center symmetric structure of the entire harvester allows for maximum energy output in a limited size. This paper studies the influence of the number of cam protrusions and the length of the cylindrical permanent magnet on the output voltage signal at different rotation speeds. When the number of cam protrusions is 3 and the length of the cylindrical magnet is 10 mm, the maximum peak-to-peak voltages of the piezoelectric and the electromagnetic power generation unit are 53.74 V and 3.16 V, respectively. The effective value power of the hybrid energy harvester can be obtained as 1.49 mW. A series of application experiments were carried out to verify the performance of the C-HEH. The hybrid energy harvester can easily light up 86 light-emitting diodes (LEDs) lights and make the scientific calculators work stably after rectification. These results demonstrate the giant prospect of piezoelectric-electromagnetic energy harvesters for supplying wireless sensor networks and low-power electronic devices.

To Evaluate Knowledge, Attitude, Practice of Natural Family Planning Method and Associated Factors among Reproductive Age Group of Women’s at Jimma Town, Jimma Zone, South West Ethiopia

Background: The high fertility rate leading to the rapid growth of country’s population is a major hindrance towards the development of a nation. Sub-Saharan Africa has the highest fertility rate in the world, which is further promoted by the low utilization of contraceptive methods. Yet, many communities claim to have natural methods of family planning that pre-date the introduction of modern contraceptives, implying that contraception is a culturally acceptable norm.
 Objective: To Evaluate the Knowledge, Attitude and Practice towards Natural family planning among reproductive age women of Jimma town, Oromia, Ethiopia.
 Methods: Across sectional community based quantitative study was done in Jimma town, among reproductive age group women from February to March; 2020. A total of3 99 sample size is calculated using single population proportion formula with a proportion (P) of 50 %.Systematic random sampling technique issued to draw the study participants among the target population. The data was collected using structured questionnaire adapted from similar and the tools modified to fit the local context. The collected data was tallied and analyzed by using scientific calculator.
 Results: From the total of 399 respondents who responded the questionnaire Majority, 90% of women in Jimma town had a good level of knowledge of natural family planning methods. A positive attitude towards natural family planning methods was seen in (68%) of the respondents.
 Conclusion: A fair level of knowledge of natural family planning methods is seen among reproductive women in Jimma town, yet differences in knowledge of specific natural family planning methods exist. Therefore, physicians and other health care providers‟ limited knowledge of and experience with Natural family planning methods inhibits broader use as reproductive age women reported getting information about NFFP methods from health providers and friends, therefore, their level of knowledge will depend largely on the information received.

The Impact of Personal Computer on Students’ Academic Performance

ABSTRACT
 This study aimed to determine the effects of Personal Computer on students' academic performance of the Grade 11 Senior High School students at MSU-Maguindanao. Specifically, this study identified the uses of Personal Computers as rated by the students in their studies, the academic performance of respondents with Personal Computer, the academic performance of respondents without Personal Computer, and the significant difference in academic performance of respondents with and without Personal Computer. Survey questionnaire was used as an instrument in gathering data. The questionnaire contains ten (10) related to the uses of computer in the students’ studies. The 10 questions are measured in terms of a 4- point scale such as: 1 for always, 2 for often, 3 for seldom and 4 for never. The statistical tools used in the analysis of data are the frequency count and the mean to describe the effects of personal computer on Senior High School students’ academic performance. The data gathered were consolidated and tabulated. The computations were done manually with the aid of scientific calculator. Findings show that the academic performance of the students with personal computer is generally higher than those without personal computer. Therefore, personal computer has effects in improving the students' academic performance.
 Keywords: Impact, Personal Computer, Students’ Academic Performance

Solving the Widlar current source transcendental equation using normal scientific calculators

The Widlar current mirror circuit is considered one of the basic circuits that STEM students encounter while learning about current sources circuits. Despite the simplicity of the circuit, the output current is given in terms of a transcendental equation in which the unknown current being calculated is inside the equation itself, in exams and in practical applications students have to solve the problem using an iterative method which sometimes gets really tedious, in this paper I am presenting a fast and accurate way for calculating the Widlar current using only a normal scientific calculator in table mode. This method is also iterative but all the steps are done using the calculator which would increase calculation speed substantially.

Effect of Micronutrient Supplements on Female Fertility

Introduction: Over the last few decades, fertility has declined globally to unprecedented low levels. Objective: Main goal was to determine whether the micronutrient supplements have any impact on female fertility. Method: This prospective observational study was conducted at the Department of Gynae and Obs, Dhaka Medical College Hospital, Dhaka, Bangladesh. Total 142 patients were enrolled in the study, during July 2019 to June 2020. Analysis of different variables were done according to standard statistical tool Spss and calculations were done using scientific calculators & using MS-excel program in computer. The present study was conducted after receiving approval from the Medical and Health Research Ethics Committee (MHREC). Result: For vitamins C and E, mean nutritional intake surpassed the estimated average requirement (EAR). There were no variations in antioxidant consumption across the groups. In multivariable models, women with a body mass index (BMI) of R25 kg/m2 had shorter TTP when they took vitamin B6 from dietary supplements. Vitamin C from dietary supplements was also linked to a shorter TTP among women with a BMI of less than 25 kg/m2. Conclusion: Women with a BMI of 25 kg/m2 had a shorter TTP when their vitamin C intake increased, while women with a BMIR of 25 kg/m2 had a shorter TTP when their vitamin B6 intake increased.

STUDENTS’ DIFFICULTIES IN UNDERSTANDING STATISTICAL CALCULATION

The paper entitled “Students’ Difficulties in Understanding Statistical Calculation” is conducted to analyze the students’ difficulty in understanding statistical calculation and the causes of it. The research is applied to the seventh semester students of English Education Study Program, Faculty of Teacher Training and Educational Sciences, Pakuan University. Students who got low score in statistics subject are chosen as the participants. Descriptive method is used in conducting this research. Questionnaire and interview are used to collect the data of this research. The result of this research shows that the students get difficulties in understanding statistical calculation. The problems are students are not able to answer statistics questions. Additionally, they are not able to understand the statistical formulas, not able to use scientific calculator, and not able to absorb the material that was taught well. Then, the causes are they are not interested in statistical calculation, they are not taught by interesting method, they were weak in calculating, and they are not familiar with scientific calculator.

A stretchable triboelectric nanogenerator made of silver-coated glass microspheres for human motion energy harvesting and self-powered sensing applications.

Wearable triboelectric nanogenerators (TENGs) have recently attracted great interest because they can convert human biomechanical energy into sustainable electricity. However, there is a need for improvement regarding the output performance and the complex fabrication of TENG devices. Here, a triboelectric nanogenerator in single-electrode mode is fabricated by a simple strategy, which involves a sandwich structure of silicone rubber and silver-coated glass microspheres (S-TENG). The S-TENG exhibits a remarkable performance in harvesting human motion energy and as flexible tactile sensor. By optimizing the device parameters and operating conditions, the maximum open-circuit voltage and short-circuit current of the S-TENG can reach up to 370 V and 9.5 μA, respectively. The S-TENG with good stretchability (300%) can be produced in different shapes and placed on various parts of the body to harvest mechanical energy for charging capacitors and powering LED lights or scientific calculators. In addition, the good robustness of the S-TENG satisfies the needs of reliability for flexible tactile sensors in realizing human–machine interfaces. This work expands the potential application of S-TENGs from wearable electronics and smart sensing systems to real-time robotics control and virtual reality/augmented reality interactions.

Proposing A Table for Weighing The Characteristics of Stratified Samples Instead of Mathematical Equations to Study Soil Characteristics Statistically

We sampled a total of four sites and four soil characteristics were selected to review some results and how to calculate the weight of these characteristics. This method of weighing soil characteristics can used in some soil surveys and classification studies, especially with regard to land evaluation and degradation studies, as well as characteristic variations, especially the delineation of soil horizons are affected by lateral and vertical variation in soil properties, which are texture, gypsum, lime, ECe, ESP, and CEC as their importance increases at the soil surface and decreases with depth as it is related to plant growth and nutrient processing, and thus it was given more weight in the upper horizons and less weight with depth, as well as studies that are concerned with finding a single value representing the pedon and not depending on the value of the characteristic in the surface horizon only. This suggested table helps in making the calculations easier and eliminates the use of the scientific calculator by converting the results of the equations in the form of a table that contains all the possibilities of variation in the thickness of the horizons. These values have been set to more than the effective depth of the soil, which is adopted within the first meter. The table has been designed for a depth of two meters in case the study requires more depths.

Methodology to improve the teaching of mathematical theories in schoolchildren, through the use of programming techniques

The science courses are and will be the basis of the students' knowledge, in this sense the mathematics course is considered the most important course because in its content it presents topics related to calculus, making their learning of vital importance in the design of educational processes. Finance a review of the state of the art we find a series of works dedicated to being able to enhance the mechanisms used for teaching, from the use of scientific calculators to reaching certain computer programs of common use, in this work a methodology is developed to be able to enhance the programming skills that teachers have in a specific area of programming, where we can consider any programming language but also any computer tool such as Excel spreadsheets. The methodology proposes the organization of topics as specific theories, such as algebra, arithmetic, trigonometry, geometry, where specific functions are developed for each specific topic, with the intention that they can be understood more easily and in turn not complicated. to the teacher in his process of adaptation of the materials and in the development of the classes. The intention is to enhance the knowledge that teachers have instead of presenting a new programming language and that they can learn in order to teach. The results show that by using the knowledge they have regarding some computer tool, we managed to organize the study materials so that it is more understandable at the time of the classes. As a conclusion we can indicate that in these times of the COVID-19 product pandemic, the methodology that is presented becomes more important because the classes are online and can help the learning of mathematics with the help of these mechanisms to organize the study materials and improve the learning processes of the math course. © 2021 Karadeniz Technical University. All rights reserved.

Impact of Scientific Calculators in Mathematics among Low- Achieving Students in a Secondary School in Kajang, Selangor

This study aims to investigate the effects of scientific calculators on mathematics achievement in support of problem-solving instructions. In this study, 49 low achieving mathematics students aged 14 years were selected from a secondary school in Kajang, Selangor, Malaysia. A pre-test post-test quasi-experimental design with two groups was employed in this action research study. The experimental group learned solid geometry and statistics topics, with the aid of a scientific calculator; while the control group did not use any technological aid to learn these topics. By controlling the pre-test score, the ANCOVA two-way test was applied to the post-test results. A positive significant difference was reported in favour of the experimental group. However, no significant interactions were noted between group and gender. The analysis results indicate that the use of a scientific calculator in the integrated teaching and learning of mathematics helped the students improved their mathematics achievements. These findings have important implications in the educational setting, particularly for educators to support and facilitate low-achieving students in mathematics.

The Learning Communities Scientific Calculator (LCSC) 45 Webinar on Problem-Solving in Mathematics

The LCSC 45 webinar was a joint community service activity between Casio Education Indonesia and Sampoerna University. This activity was held in the form of online sharing session for mathematics teachers, with the topic Problem-Solving in Mathematics. The LCSC 45 webinar aimed to share ideas and build awareness of the importance of Problem-Solving in Mathematics. Most participants were very satisfied with the speaker’s facilitation and sure that they understood mathematical problem-solving. The webinar activities were rated as attractive because of its rich contents, challenging problem-solving questions, the use of Padlet and sharing links via barcode. However, some obstacles were still encountered, such as unstable internet connections and limited webinar time duration. For future improvement, it was suggested to fully assist teachers in designing and implementing problem-solving in a mathematics lesson.