• Title/Summary/Keyword: American mathematics

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Application of waste tire rubber aggregate in porous concrete

  • Shariati, Mahdi;Heyrati, Arian;Zandi, Yousef;Laka, Hossein;Toghroli, Ali;Kianmehr, Peiman;Safa, Maryam;Salih, Musab N.A.;Poi-Ngian, Shek
    • Smart Structures and Systems
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    • v.24 no.4
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    • pp.553-566
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    • 2019
  • This study aimed to categorize pervious rubberized concrete into fresh and hardened concrete analyzing its durability, permeability and strength. During the globalization of modern life, growing population and industry rate have signified a sustainable approach to all aspects of modern life. In recent years, pervious concrete (porous concrete) has significantly substituted for pavements due to its mechanical and environmental properties. On the other hand, scrap rubber tire has been also contributed with several disposal challenges. Considering the huge amount of annually tire wastes tossing out, the conditions become worse. Pervious concrete (PC) gap has graded surface assisted with storm water management, recharging groundwater sources and alleviate water run-offs. The results have shown that the use of waste tires as aggregate built into pervious concrete has tremendously reduced the scrap tire wastes enhancing environmental compliance.

Review for the Curriculum and License Exam of Physical Therapists in the United States

  • Choi, Chi-Whan;Jeong, Yeon-Gyu
    • The Journal of Korean Physical Therapy
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    • v.31 no.4
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    • pp.184-192
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    • 2019
  • Purpose: This study was conducted to review the curriculum and license examination of physical therapists in the United States. Methods: The doctor of physical therapy (DPT) curriculum was evaluated by a review Course Work Tool version 6 (CWT6) data and current physical therapy licensure examination (National Physical Therapy Exam, NPTE) category in the United States. Results: The results indicated that they were required to meet the doctor of physical therapist degree based on 'Guide to Physical Therapist Practice' of American Physical Therapy Association (APTA). This includes general education in the areas of communications and humanities, physical science, biological science, social and behavioral science, and mathematics. A minimum of one course must be completed successfully in each area of general education. Moreover, there should be at least 68 didactic credits of professional education and 22 clinical education credits, which is a minimum of two full-time clinical internships with no less than 1050 hours in total, which were supervised by a physical therapist. Regarding the physical therapy licensure examination, National Physical Therapy Exam (NPTE, 2016) consisted of a physical therapy examination (26.5%), evaluation, differential diagnosis, baseline of prognosis (32.5%), intervention (28.5%), protection, responsibility, and research (6.5%) based on the 'Guide to Physical Therapist Practice'. Conclusion: Based on the study results provided above, it is considered a standard to meet domestic reality as the Guide to Physical Therapist Practice of APTA for South Korean physical therapists.

Development, validation and implementation of multiple radioactive particle tracking technique

  • Mehul S. Vesvikar;Thaar M. Aljuwaya;Mahmoud M. Taha;Muthanna H. Al-Dahhan
    • Nuclear Engineering and Technology
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    • v.55 no.11
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    • pp.4213-4227
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    • 2023
  • Computer Automated Radioactive Particle Tracking (CARPT) technique has been successfully utilized to measure the velocity profiles and mixing parameters in different multiphase flow systems where a single radioactive tracer is used to track the tagged phase. However, many industrial processes use a wide range of particles with different physical properties where solid particles could vary in size, shape and density. For application in such systems, the capability of current single tracer CARPT can be advanced to track more than one particle simultaneously. Tracking multiple particles will thus enable to track the motion of particles of different size shape and density, determine segregation of particles and probing particle interactions. In this work, a newly developed Multiple Radioactive Particle Tracking technique (M-RPT) used to track two different radioactive tracers is demonstrated. The M-RPT electronics was developed that can differentiate between gamma counts obtained from the different radioactive tracers on the basis of their gamma energy peak. The M-RPT technique was validated by tracking two stationary and moving particles (Sc-46 and Co-60) simultaneously. Finally, M-RPT was successfully implemented to track two phases, solid and liquid, simultaneously in three phase slurry bubble column reactors.

A Comparative Analysis of Introducing Addition and Subtraction in the Korean, Singaporean, American, and Japanese Elementary Textbooks (한국, 싱가포르, 미국, 일본의 초등학교 교과서에 제시된 덧셈과 뺄셈 도입에 대한 비교분석)

  • Pang, JeongSuk;Kim, Leena;Kim, SoHyeon
    • Communications of Mathematical Education
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    • v.36 no.2
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    • pp.229-252
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    • 2022
  • This study analyzed the introduction of addition and subtraction, including the composition and decomposition of numbers in the Korean, Singaporean, American, and Japanese elementary mathematics textbooks. The analytic foci of this study included visual models and their connections with the given problem contexts, the introduction of addition/subtraction or addition/subtraction sentences and their connections with the visual models, and additional activities for students to develop a relational understanding of the equal sign. The results of the analysis demonstrated diverse connections, mainly because the problem contexts, visual models, and the introduction of addition/subtraction or addition/subtraction sentences were implemented differently for each textbook. There were differences among the textbooks in what order of problem contexts were presented. Regarding the use of visual models, two textbooks tended to use one model consistently, whereas the other textbooks used various models depending on the problem contexts. There were subtle but significant differences in introducing addition/subtraction or addition/subtraction sentences. For a relational understanding of the equal sign, all textbooks included activities emphasizing that both sides of the equal sign are equal. Based on the results of this study, this paper closes with several implications related to the problem contexts to introduce addition/subtraction and addition/subtraction sentences as well as the use of visual models, which can serve as a basis for a new unit for the subsequent textbook.

Survey of American food trends and the growing obesity epidemic

  • Shao, Qin;Chin, Khew-Voon
    • Nutrition Research and Practice
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    • v.5 no.3
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    • pp.253-259
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    • 2011
  • The rapid rise in the incidence of obesity has emerged as one of the most pressing global public health issues in recent years. The underlying etiological causes of obesity, whether behavioral, environmental, genetic, or a combination of several of them, have not been completely elucidated. The obesity epidemic has been attributed to the ready availability, abundance, and overconsumption of high-energy content food. We determined here by Pearson's correlation the relationship between food type consumption and rising obesity using the loss-adjusted food availability data from the United States Department of Agriculture (USDA) Economic Research Services (ERS) as well as the obesity prevalence data from the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health and Nutrition Examination Survey (NHANES) at the Centers for Disease Control and Prevention (CDC). Our analysis showed that total calorie intake and consumption of high fructose com syrup (HFCS) did not correlate with rising obesity trends. Intake of other major food types, including chicken, dairy fats, salad and cooking oils, and cheese also did not correlate with obesity trends. However, our results surprisingly revealed that consumption of com products correlated with rising obesity and was independent of gender and race/ethnicity among population dynamics in the U.S. Therefore, we were able to demonstrate a novel link between the consumption of com products and rising obesity trends that has not been previously attributed to the obesity epidemic. This correlation coincides with the introduction of bioengineered corns into the human food chain, thus raising a new hypothesis that should be tested in molecular and animal models of obesity.

Comparison of survival prediction models for pancreatic cancer: Cox model versus machine learning models

  • Kim, Hyunsuk;Park, Taesung;Jang, Jinyoung;Lee, Seungyeoun
    • Genomics & Informatics
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    • v.20 no.2
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    • pp.23.1-23.9
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    • 2022
  • A survival prediction model has recently been developed to evaluate the prognosis of resected nonmetastatic pancreatic ductal adenocarcinoma based on a Cox model using two nationwide databases: Surveillance, Epidemiology and End Results (SEER) and Korea Tumor Registry System-Biliary Pancreas (KOTUS-BP). In this study, we applied two machine learning methods-random survival forests (RSF) and support vector machines (SVM)-for survival analysis and compared their prediction performance using the SEER and KOTUS-BP datasets. Three schemes were used for model development and evaluation. First, we utilized data from SEER for model development and used data from KOTUS-BP for external evaluation. Second, these two datasets were swapped by taking data from KOTUS-BP for model development and data from SEER for external evaluation. Finally, we mixed these two datasets half and half and utilized the mixed datasets for model development and validation. We used 9,624 patients from SEER and 3,281 patients from KOTUS-BP to construct a prediction model with seven covariates: age, sex, histologic differentiation, adjuvant treatment, resection margin status, and the American Joint Committee on Cancer 8th edition T-stage and N-stage. Comparing the three schemes, the performance of the Cox model, RSF, and SVM was better when using the mixed datasets than when using the unmixed datasets. When using the mixed datasets, the C-index, 1-year, 2-year, and 3-year time-dependent areas under the curve for the Cox model were 0.644, 0.698, 0.680, and 0.687, respectively. The Cox model performed slightly better than RSF and SVM.

Static analysis of nonlinear FG-CNT reinforced nano-composite beam resting on Winkler/Pasternak foundation

  • Mostefa Sekkak;Rachid Zerrouki;Mohamed Zidour;Abdelouahed Tounsi;Mohamed Bourada;Mahmoud M Selim;Hosam A. Saad
    • Advances in nano research
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    • v.16 no.5
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    • pp.509-519
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    • 2024
  • In this study, the static analysis of carbon nanotube-reinforced composites (CNTRC) beams resting on a Winkler-Pasternak elastic foundation is presented. The developed theories account for higher-order variation of transverse shear strain through the depth of the beam and satisfy the stress-free boundary conditions on the top and bottom surfaces of the beam. To study the effect of carbon nanotubes distribution in functionally graded (FG-CNT), we introduce in the equation of CNT volume fraction a new exponent equation. The SWCNTs are assumed to be aligned and distributed in the polymeric matrix with different patterns of reinforcement. The rule of mixture is used to describe the material properties of the CNTRC beams. The governing equations were derived by employing Hamilton's principle. The models presented in this work are numerically provided to verify the accuracy of the present theory. The analytical solutions are presented, and the obtained results are compared with the existing solutions to verify the validity of the developed theories. Many parameters are investigated, such as the Pasternak shear modulus parameter, the Winkler modulus parameter, the volume fraction, and the order of the exponent in the volume fraction equation. New results obtained from bending and stresses are presented and discussed in detail. From the obtained results, it became clear the influence of the exponential CNTs distribution and Winkler-Pasternak model improved the mechanical properties of the CNTRC beams.

School Earth Science Curriculum Reflected in Exhibits and an Educational Analysis of Exhibition Methods: Cases of Natural History Museums in the U.S. (자연사 박물관 전시물의 학교 지구과학 교육과정 반영 정도와 전시 방법의 교육적 분석: 미국의 사례를 중심으로)

  • Kim, Chan-Jong;Shin, Myeong-Kyeong;Lee, Chang-Zin;Cha, Hyun-Jeong
    • Journal of the Korean earth science society
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    • v.27 no.2
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    • pp.130-139
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    • 2006
  • Natural history museums used to be called an "informal learning institute". It is based on the assumption that their exhibition and exhibits are supposed to reflect school science curriculum and support school science programs. This study is to explore how this assumption is verified in terms of content-wise connections between school science and museum exhibits. In this study, 461 Earth Science related exhibits were selected from the Smithonian Museums and the American Museum of Natural History in the U.S. and analyzed with several instruments. The instrument targeting on Earth Science curriculum was framed based on the Third International Mathematics and Science Study (1993) and the National Science Curriculum Standards (1996). Other than content-wise connections, this study investigated exhibition characteristics related to better learning of science: these characteristics were types of activities, exhibition media, exhibition technology, and presentation methods. The nature of science shown in exhibits were examined as well. Natural history museums were reconsidered for their relevance and potential as informal educational venues from this study.