Chemically based mathematical model for development of cerebral cortical folding patterns.
Directory of Open Access Journals (Sweden)
Deborah A Striegel
2009-09-01
Full Text Available The mechanism for cortical folding pattern formation is not fully understood. Current models represent scenarios that describe pattern formation through local interactions, and one recent model is the intermediate progenitor model. The intermediate progenitor (IP model describes a local chemically driven scenario, where an increase in intermediate progenitor cells in the subventricular zone correlates to gyral formation. Here we present a mathematical model that uses features of the IP model and further captures global characteristics of cortical pattern formation. A prolate spheroidal surface is used to approximate the ventricular zone. Prolate spheroidal harmonics are applied to a Turing reaction-diffusion system, providing a chemically based framework for cortical folding. Our model reveals a direct correlation between pattern formation and the size and shape of the lateral ventricle. Additionally, placement and directionality of sulci and the relationship between domain scaling and cortical pattern elaboration are explained. The significance of this model is that it elucidates the consistency of cortical patterns among individuals within a species and addresses inter-species variability based on global characteristics and provides a critical piece to the puzzle of cortical pattern formation.
Mathematical Modeling of Chemical Stoichiometry
Croteau, Joshua; Fox, William P.; Varazo, Kristofoland
2007-01-01
In beginning chemistry classes, students are taught a variety of techniques for balancing chemical equations. The most common method is inspection. This paper addresses using a system of linear mathematical equations to solve for the stoichiometric coefficients. Many linear algebra books carry the standard balancing of chemical equations as an…
Directory of Open Access Journals (Sweden)
Basuki Widodo
2012-02-01
Full Text Available Corrosion process is a natural case that happened at the various metals, where the corrosion process in electrochemical can be explained by using galvanic cell. The iron corrosion process is based on the acidity degree (pH of a condensation, iron concentration and condensation temperature of electrolyte. Those are applied at electrochemistry cell. The iron corrosion process at this electrochemical cell also able to generate electrical potential and electric current during the process takes place. This paper considers how to build a mathematical model of iron corrosion, electrical potential and electric current. The mathematical model further is solved using the finite element method. This iron corrosion model is built based on the iron concentration, condensation temperature, and iteration time applied. In the electric current density model, the current based on electric current that is happened at cathode and anode pole and the iteration time applied. Whereas on the potential electric model, it is based on the beginning of electric potential and the iteration time applied. The numerical results show that the part of iron metal, that is gristle caused by corrosion, is the part of metal that has function as anode and it has some influences, such as time depth difference, iron concentration and condensation temperature on the iron corrosion process and the sum of reduced mass during corrosion process. Moreover, difference influence of time and beginning electric potential has an effect on the electric potential, which emerges during corrosion process at the electrochemical cell. Whereas, at the electrical current is also influenced by difference of depth time and condensation temperature applied.Keywords: Iron Corrosion, Concentration of iron, Electrochemical Cell and Finite Element Method
Basuki Widodo
2012-01-01
Corrosion process is a natural case that happened at the various metals, where the corrosion process in electrochemical can be explained by using galvanic cell. The iron corrosion process is based on the acidity degree (pH) of a condensation, iron concentration and condensation temperature of electrolyte. Those are applied at electrochemistry cell. The iron corrosion process at this electrochemical cell also able to generate electrical potential and electric current during the process takes p...
Mathematical modeling a chemical engineer's perspective
Rutherford, Aris
1999-01-01
Mathematical modeling is the art and craft of building a system of equations that is both sufficiently complex to do justice to physical reality and sufficiently simple to give real insight into the situation. Mathematical Modeling: A Chemical Engineer's Perspective provides an elementary introduction to the craft by one of the century's most distinguished practitioners.Though the book is written from a chemical engineering viewpoint, the principles and pitfalls are common to all mathematical modeling of physical systems. Seventeen of the author's frequently cited papers are reprinted to illus
Identification of Chemical Reactor Plant’s Mathematical Model
Directory of Open Access Journals (Sweden)
Pyakillya Boris
2015-01-01
Full Text Available This work presents a solution of the identification problem of chemical reactor plant’s mathematical model. The main goal is to obtain a mathematical description of a chemical reactor plant from experimental data, which based on plant’s time response measurements. This data consists sequence of measurements for water jacket temperature and information about control input signal, which is used to govern plant’s behavior.
Chemical Graph Theory--The Mathematical Connection
Gutman, Ivan
The impact that research done in chemical graph theory (CGT) had and has on "serious" or "pure" mathematics is examined. Although this impact is minor, it is not fully negligible. By means of two case studies we intend to demonstrate the following general features of the CGT --> Mathematics connection: (a) Scholars familiar with chemistry design a mathematical model of the examined chemical phenomena; (b) such a model may require the usage of non-trivial mathematical objects and methods, and may lead to difficult and interesting mathematical problems; (c) in order to grasp the significance of a particular mathematical object/method/problem of CGT, mathematicians need a very long time, sometimes as much as 20-30 years; (d) once this significance is recognized, a vigorous mathematical research begins; (e) mathematicians usually generalize and extend the original object/method/problem of CGT, and the results they obtain may be lacking value for CGT. The two case studies pertain to the graph energy and the connectivity (or Randic) index.
Basitere, Moses; Ivala, Eunice
2015-01-01
This paper reports on a study carried out at a University of Technology, South Africa, aimed at identifying the existence of the mathematical knowledge gap and evaluating the intervention designed to bridge the knowledge gap amongst students studying first year mathematics at the Chemical Engineering Extended Curriculum Program (ECP). In this…
A New Mathematical Formulation of the Governing Equations for the Chemical Compositional Simulation
Bekbauov, Bakhbergen E; Berdyshev, Abdumauvlen
2015-01-01
It is the purpose of this work to develop new approach for chemical compositional reservoir simulation, which may be regarded as a sequential method. The development process can be roughly divided into the following two stages: (1) development of a new mathematical formulation for the sequential chemical compositional reservoir simulation, (2) implementation of a sequential solution approach for chemical compositional reservoir simulation based on the formulation described in this paper. This paper addresses the first stage of the development process by presenting a new mathematical formulation of the chemical compositional reservoir flow equations for the sequential simulation. The newly developed mathematical formulation is extended from the model formulation used in existing chemical compositional simulators. During the model development process, it was discovered that the currently used chemical compositional model estimates the adsorption effect on the transport of a component reasonably well but it viol...
Mathematical Modeling of Tin-Free Chemically-Active Antifouling Paint Behavior
DEFF Research Database (Denmark)
Yebra, Diego Meseguer; Kiil, Søren; Dam-Johansen, Kim;
2006-01-01
Mathematical modeling has been used to characterize and validate the working mechanisms of tin-free, chemically-active antifouling (AF) paints. The model-based analysis of performance data from lab-scale rotary experiments has shown significant differences between antifouling technologies as rega...... of Chemical Engineers....
Conceptualising inquiry based education in mathematics
DEFF Research Database (Denmark)
Blomhøj, Morten; Artigue, Michéle
2013-01-01
The terms inquiry-based learning (IBL) and inquiry-based education (IBE) have appeared with increasing frequency in educational policy and curriculum documents related to mathematics and science education over the past decade, indicating a major educational trend. We go back to the origin of...... frameworks in mathematics education. Six such frameworks are analysed from the perspective of inquiry: the problem-solving tradition, the Theory of Didactical Situations, the Realistic Mathematics Education programme, the mathematical modelling perspective, the Anthropological Theory of Didactics, and the...... inquiry as a pedagogical concept in the work of Dewey (e.g. 1916, 1938) to analyse and discuss its migration to science and mathematics education. For conceptualizing inquiry-based mathematics education (IBME) it is important to analyse how this concept resonates with already well-established theoretical...
Chemical Literacy Levels of Science and Mathematics Teacher Candidates
Celik, Suat
2014-01-01
The goal of this study was to investigate Turkish science and mathematics teacher candidates' levels of attainment in chemical literacy. These candidates had all studied the new Turkish chemistry curriculum in high school. The sample of the study consisted of 112 students, who were first-year students in the Department of Secondary Science…
Ge, Hao
2016-01-01
This paper studies a mathematical formalism of nonequilibrium thermodynamics for chemical reaction models with $N$ species, $M$ reactions, and general rate law. We establish a mathematical basis for J. W. Gibbs' macroscopic chemical thermodynamics under G. N. Lewis' kinetic law of entire equilibrium (detailed balance in nonlinear chemistry kinetics). In doing so, the equilibrium thermodynamics is then naturally generalized to nonequilibrium settings without detailed balance. The kinetic models are represented by a Markovian jumping process. A generalized macroscopic chemical free energy function and its associated balance equation with nonnegative source and sink are the major discoveries. The proof is based on the large deviation principle of this type of Markov processes. A general fluctuation dissipation theorem for stochastic reaction kinetics is also proved. The mathematical theory illustrates how a novel macroscopic dynamic law can emerges from the mesoscopic kinetics in a multi-scale system.
Mesoscopic Kinetic Basis of Macroscopic Chemical Thermodynamics: A Mathematical Theory
Ge, Hao
2016-01-01
From a mathematical model that describes a complex chemical kinetic system of $N$ species and $M$ elementrary reactions in a rapidly stirred vessel of size $V$ as a Markov process, we show that a macroscopic chemical thermodynamics emerges as $V\\rightarrow\\infty$. The theory is applicable to linear and nonlinear reactions, closed systems reaching chemical equilibrium, or open, driven systems approaching to nonequilibrium steady states. A generalized mesoscopic free energy gives rise to a macroscopic chemical energy function $\\varphi^{ss}(\\vx)$ where $\\vx=(x_1,\\cdots,x_N)$ are the concentrations of the $N$ chemical species. The macroscopic chemical dynamics $\\vx(t)$ satisfies two emergent laws: (1) $(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]\\le 0$, and (2)$(\\rd/\\rd t)\\varphi^{ss}[\\vx(t)]=\\text{cmf}(\\vx)-\\sigma(\\vx)$ where entropy production rate $\\sigma\\ge 0$ represents the sink for the chemical energy, and chemical motive force $\\text{cmf}\\ge 0$ is non-zero if the system is driven under a sustained nonequilibrium chemos...
Developing Mathematics Problems Based on Pisa Level
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Shahibul Ahyan
2014-01-01
Full Text Available This research aims to produce mathematics problems based on PISA level with valid and practical content of change and relationships and has potential effect for Junior High School students. A development research method developed by Akker, Gravemeijer, McKenney and Nieveen is used this research. In the first stage, the researcher analyzed students, algebra material in school-based curricula (KTSP and mathematics problems of PISA 2003 of change and relationships content. The second stage, the researcher designed 13 problems with content of change and relationships. The last, the researcher used formative evaluation design developed by Tessmer which includes self evaluation, one-to-one, expert review, small group, and field test. The data collect by walk through, interview, and questionnaire. The result of this research indicated that 12 mathematical problems based on PISA level of change and relationships content that developed have validity, practically, and potential effects for Junior High School students.
A mathematical model of symmetry based on mathematical definition
Institute of Scientific and Technical Information of China (English)
刘玉生; 杨将新; 吴昭同; 高曙明
2002-01-01
Tolerance is imperative for seamless integration of CAD/CAM(Computer Aided Disignd/Computer Aided Manufacture) which is just a text attribute and has no semantics in present CAD systems. There are many tolerance types, the relations between which are very complicated. In addition, the different principles of tolerance make study of tolerance difficult; and there may be various meanings or interpretation for the same type of tolerance beeanse of the literal definition. In this work, latest unambiguous mathematical definition was applied to study, explain and clarify: ( 1 ) the formation and representation of tolerance zone, and (2) the formation and representation of variational elements ; after which, the mathematical models of syrmmetry of different tolerance principles and different interpretations were derived. An example is given to illustrate the application of these models in tolerance analysis.
Mathematical programming solver based on local search
Gardi, Frédéric; Darlay, Julien; Estellon, Bertrand; Megel, Romain
2014-01-01
This book covers local search for combinatorial optimization and its extension to mixed-variable optimization. Although not yet understood from the theoretical point of view, local search is the paradigm of choice for tackling large-scale real-life optimization problems. Today's end-users demand interactivity with decision support systems. For optimization software, this means obtaining good-quality solutions quickly. Fast iterative improvement methods, like local search, are suited to satisfying such needs. Here the authors show local search in a new light, in particular presenting a new kind of mathematical programming solver, namely LocalSolver, based on neighborhood search. First, an iconoclast methodology is presented to design and engineer local search algorithms. The authors' concern about industrializing local search approaches is of particular interest for practitioners. This methodology is applied to solve two industrial problems with high economic stakes. Software based on local search induces ex...
From (Deductive) Fuzzy Logic to (Logic-Based) Fuzzy Mathematics
Czech Academy of Sciences Publication Activity Database
Cintula, Petr
Berlin: Springer, 2009 - (Sossai, C.; Chemello, G.) ISBN 978-3-642-02905-9. ISSN 0302-9743. [ECSQARU 2009. European Conference /10./. 01.07.2009-03.07. 2009, Verona] Institutional research plan: CEZ:AV0Z10300504 Keywords : fuzzy class theory * non-classical mathematics * logic-based fuzzy mathematics Subject RIV: BA - General Mathematics
Place-Based Mathematics Education: A Conflated Pedagogy?
Showalter, Daniel A.
2013-01-01
Place-based mathematics education (PBME) has the potential to engage students with the mathematics inherent in the local land, culture, and community. However, research has identified daunting barriers to this pedagogy, especially in abstract mathematics courses such as algebra and beyond. In this study, 15 graduates of a doctoral program in rural…
Biza, Irene; Nardi, Elena; Joel, Gareth
2015-01-01
In this paper we present the results from a study conducted in a UK institution in which 21mathematics pre-service teachers engage with two practice-based tasks featuring incidents where classroom management interferes with mathematical learning. We investigate their considerations when they make decisions in classroom situations and how these tasks can trigger their reflections on the teaching and learning of mathematics. In our analysis we used the constructs of social and sociomathematical...
Mathematical Expression Recognition based on Probabilistic Grammars
Álvaro Muñoz, Francisco
2015-01-01
[EN] Mathematical notation is well-known and used all over the world. Humankind has evolved from simple methods representing countings to current well-defined math notation able to account for complex problems. Furthermore, mathematical expressions constitute a universal language in scientific fields, and many information resources containing mathematics have been created during the last decades. However, in order to efficiently access all that information, scientific doc...
Paterson, Judy; Sneddon, Jamie
2011-01-01
This article reports on the learning conversations between a mathematician and a mathematics educator as they worked together to change the delivery model of a third year discrete mathematics course from a traditional lecture mode to team-based learning (TBL). This change prompted the mathematician to create team tasks which increasingly focused…
Ge, Hao; Qian, Hong
2016-01-01
This paper studies a mathematical formalism of nonequilibrium thermodynamics for chemical reaction models with $N$ species, $M$ reactions, and general rate law. We establish a mathematical basis for J. W. Gibbs' macroscopic chemical thermodynamics under G. N. Lewis' kinetic law of entire equilibrium (detailed balance in nonlinear chemistry kinetics). In doing so, the equilibrium thermodynamics is then naturally generalized to nonequilibrium settings without detailed balance. The kinetic model...
Teacher practice in an inquiry-based Mathematics classroom
Menezes, Luís; Oliveira, Hélia; Canavarro, Ana Paula
2012-01-01
This paper presents a framework for an inquiry-based approach to mathematics teaching. It was developed by combining theoretical perspectives and case studies of experienced teacher that usually conduct inquiry based teaching of mathematics. This framework describes the actions teachers intentionally perform with two identified purposes: to promote the mathematical learning of the students and to manage the students and the class as a whole.
A Study of Mathematics Web-Based Learning in Schools
Directory of Open Access Journals (Sweden)
Mansoor A.A Ali
2008-01-01
Full Text Available Teaching Mathematics to intermediate school boys is a challenging process which can greatly benefit from software technology and web-based learning. In this research we study the difficulties and opportunities of using this technology in teaching Mathematics to 13 year old boys studying Mathematics at school. For students' we identify the basic requirements at home, e.g., Mathematics computer software packages, availability of internet access and ability of the parents to provide computers, software and the internet for their sons. We assess the expected improvement in grades, motivation and communication between home and school. For the teaches', we assess the expected improvement in teachers' productivity, teachers' experience, qualifications in computing and Mathematics packages and their anticipated expectations such as improvement in problem solving, grades of students. Our main objective is to determine the expected results resulting from applying computer software and web-based learning in teaching Mathematics.
Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics
Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander
2010-01-01
We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to introduce students to mathematical methods beyond the interface of biology with calculus. Based on ongoing research, and designed to use the project-...
Web-Based Mathematics: Some "Dos" and "Don'ts"
Loong, Esther Yook-Kin
2011-01-01
This case study describes an "out of field" teacher's use of the Internet to teach a range of mathematical topics in a modified Year 8 mathematics class. It highlights the importance of three factors for implementing a discernible web-based teaching strategy: appropriate choice of web objects, effective "virtual" pedagogy, and technical support…
Inquiry-Based Learning and the Art of Mathematical Discourse
von Renesse, Christine; Ecke, Volker
2015-01-01
Our particular flavor of inquiry-based learning (IBL) uses mathematical discourse, conversations, and discussions to empower students to deepen their mathematical thinking, building on strengths of students in the humanities. We present an organized catalog of powerful questions, discussion prompts, and talk moves that can help faculty facilitate…
Lev, Felix M.
2014-01-01
Classical mathematics (involving such notions as infinitely small/large and continuity) is usually treated as fundamental while finite mathematics is treated as inferior which is used only in special applications. We first argue that the situation is the opposite: classical mathematics is only a degenerate special case of finite one and finite mathematics is more pertinent for describing nature than standard one. Then we describe results of a quantum theory based on finite mathematics. Implic...
Mathematical modeling of quartz particle melting process in plasma-chemical reactor
Energy Technology Data Exchange (ETDEWEB)
Volokitin, Oleg, E-mail: volokitin-oleg@mail.ru; Volokitin, Gennady, E-mail: vgg-tomsk@mail.ru; Skripnikova, Nelli, E-mail: nks2003@mai.ru; Shekhovtsov, Valentin, E-mail: shehovcov2010@yandex.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); Vlasov, Viktor, E-mail: rector@tsuab.ru [Tomsk State University of Architecture and Building, 2, Solyanaya Sq., 634003, Tomsk (Russian Federation); National Research Tomsk Polytechnic University, 30, Lenin Ave., 634050, Tomsk (Russian Federation)
2016-01-15
Among silica-based materials vitreous silica has a special place. The paper presents the melting process of a quartz particle under conditions of low-temperature plasma. A mathematical model is designed for stages of melting in the experimental plasma-chemical reactor. As calculation data show, quartz particles having the radius of 0.21≤ r{sub p} ≤0.64 mm completely melt at W = 0.65 l/s particle feed rate depending on the Nusselt number, while 0.14≤ r{sub p} ≤0.44 mm particles melt at W = 1.4 l/s. Calculation data showed that 2 mm and 0.4 mm quartz particles completely melted during and 0.1 s respectively. Thus, phase transformations occurred in silicon dioxide play the important part in its heating up to the melting temperature.
Mathematical modeling of quartz particle melting process in plasma-chemical reactor
Volokitin, Oleg; Vlasov, Viktor; Volokitin, Gennady; Skripnikova, Nelli; Shekhovtsov, Valentin
2016-01-01
Among silica-based materials vitreous silica has a special place. The paper presents the melting process of a quartz particle under conditions of low-temperature plasma. A mathematical model is designed for stages of melting in the experimental plasma-chemical reactor. As calculation data show, quartz particles having the radius of 0.21≤ rp ≤0.64 mm completely melt at W = 0.65 l/s particle feed rate depending on the Nusselt number, while 0.14≤ rp ≤0.44 mm particles melt at W = 1.4 l/s. Calculation data showed that 2 mm and 0.4 mm quartz particles completely melted during and 0.1 s respectively. Thus, phase transformations occurred in silicon dioxide play the important part in its heating up to the melting temperature.
Mathematical modeling of quartz particle melting process in plasma-chemical reactor
International Nuclear Information System (INIS)
Among silica-based materials vitreous silica has a special place. The paper presents the melting process of a quartz particle under conditions of low-temperature plasma. A mathematical model is designed for stages of melting in the experimental plasma-chemical reactor. As calculation data show, quartz particles having the radius of 0.21≤ rp ≤0.64 mm completely melt at W = 0.65 l/s particle feed rate depending on the Nusselt number, while 0.14≤ rp ≤0.44 mm particles melt at W = 1.4 l/s. Calculation data showed that 2 mm and 0.4 mm quartz particles completely melted during and 0.1 s respectively. Thus, phase transformations occurred in silicon dioxide play the important part in its heating up to the melting temperature
Mathematical Formulation of DMH-Based Inverse Optimization
Mihaylov, Ivaylo B.; Moros, Eduardo G.
2014-01-01
Purpose: To introduce the concept of dose–mass-based inverse optimization for radiotherapy applications. Materials and Methods: Mathematical derivation of the dose–mass-based formalism is presented. This mathematical representation is compared to the most commonly used dose–volume-based formulation used in inverse optimization. A simple example on digitally created phantom is presented. The phantom consists of three regions: a target surrounded by high- and low-density regions. The target ...
Mathematical modeling of the radiation-chemical behavior of Np(VI) in HNO3
International Nuclear Information System (INIS)
The literature contains many studies on the radiolytic behavior of Np(VI) in HNO3 solutions. These studies have been partially reviewed in a book. An attempt has been made to examine the mechanism of the radiation-chemical conversion of Np ions. However, the kinetic laws cannot be obtained and the mechanism of the reactions occurring cannot be accurately found without mathematical modeling. Mathematical modeling of the radiation-chemical behavior of Np(VI) in 0.5-6 M HNO3 is reported in the present article. Calculations using a special program were performed on an IBM PC/X5 personal computer
Akiba, Motoko; Chiu, Ya-Fang; Zhuang, Yue-Lin; Mueller, Heather E.
2008-01-01
Using the NAEP nationally-representative data collected from eighth-graders, we investigated the relative exposure of American Indian/Alaska Native (AIAN) students to mathematics teachers who are knowledgeable about standards, participate in standards-based professional development, and practice standards-based instruction; American Indian/Alaska…
Mathematical model on surface reaction diffusion in the presence of front chemical reaction
Permikin, D. V.; Zverev, V. S.
2013-01-01
The article discusses a mathematical model of solid-phase diffusion over substance surface accompanied a frontal chemical reaction. The purpose of our article is to describe the concentration distribution and surface reacted layer growth. The model is a system parabolic equations, complicated with the presence of mobile front. It takes account of diffusive fluxes redistribution, sublimation from the surface, chemical reaction reversibility. The asymptotic approximation of the obtained nonline...
A mathematical model for the transport and fate of organic chemicals in unsaturated/saturated soils.
Lindstrom, F T; Piver, W T
1985-01-01
A mathematical model, simulating the transport and fate of nonionizable organic compounds in unsaturated/saturated porous media (soils) in a terrestrial microcosm has been developed. Using the principles of water mass, momentum, heat energy and chemical mass balance, the three fields: moisture, temperature, and liquid phase chemical concentration are solved for simultaneously by coupling the soil slab to an environmentally realistic air-soil interface (a dynamic free boundary) conditions and ...
A New Activity-Based Cost (ABC) Mathematical Model
Institute of Scientific and Technical Information of China (English)
JIANG Shuo; SONG Lei
2003-01-01
Along with the product price competition growing intensely, it is apparently important for reasonably distributing and counting cost. But, in sharing indirect cost, traditional cost accounting unveils the limitations increasingly, especially in authenticity of cost information. And the accounting theory circles and industry circles begin seeking one kind of new accurate cost calculation method, and the activity-based cost (ABC) method emerges as the times require. In this paper, we will build its mathematical model by the basic principle of ABC, and will improve its mathematical model further. We will establish its comparison mathematical model and make the ABC method go a step further to its practical application.
Stein, Sherman K
2010-01-01
Anyone can appreciate the beauty, depth, and vitality of mathematics with the help of this highly readable text, specially developed from a college course designed to appeal to students in a variety of fields. Readers with little mathematical background are exposed to a broad range of subjects chosen from number theory, topology, set theory, geometry, algebra, and analysis. Starting with a survey of questions on weight, the text discusses the primes, the fundamental theorem of arithmetic, rationals and irrationals, tiling, tiling and electricity, probability, infinite sets, and many other topi
International Nuclear Information System (INIS)
The 1988 progress report of the Mathematics center (Polytechnic School, France), is presented. The Center is composed of different research teams: analysis, Riemann geometry, group theory, formal calculus and algorithm geometry, dynamical systems, topology and singularity. For each team, the members, the research topics, the national and international cooperations, are given. The papers concerning the investigations carried out in 1988, are listed
Intelligent Forecasting of Sintered Ore's Chemical Components Based on SVM
Institute of Scientific and Technical Information of China (English)
ZHONG Luo; WANG Qingbo; YUAN Jingling
2011-01-01
Using object mathematical model of traditional control theory can not solve the forecasting problem of the chemical components of sintered ore. In order to control complicated chemical components in the manufacturing process of sintered ore, some key techniques for intelligent forecasting of the chemical components of sintered ore are studied in this paper. A new intelligent forecasting system based on SVM is proposed and realized. The results show that the accuracy of predictive value of every component is more than 90%. The application of our system in related companies is for more than one year and has shown satisfactory results.
Resilience of chemical industrial areas through attenuation-based security
International Nuclear Information System (INIS)
This paper investigates the possibility of attenuation-based security within chemical industrial areas. Representing chemical industrial areas as mathematical networks, we prove by case-study that the resilience to disaster of such areas may follow a power-law distribution. Furthermore, we examine what happens to the network when highly hazardous installations would be intelligently protected against malicious acts: the network disintegrates into separate smaller networks. Hence, islands are formed with no escalation danger in between. We conclude that it is possible to protect chemical industrial areas in such a way that they are more resilient against terrorism
Problem-based learning and teacher training in mathematics
Cazzola, Marina
2008-01-01
Problem-based learning (PBL) is a constructivist learner-centered instructional approach based on the analysis, resolution and discussion of a given problem. It can be applied to any subject, indeed it is especially useful for the teaching of mathematics. When compared to ``traditional'' teaching, the PBL approach requires increased responsibility for the teachers (in addition to the presentation of mathematical knowledge, they need to engage students in gathering information and using their knowledge to solve given problems). It thus become crucial that the future teachers become aware of its effectiveness. One of the main obstacle to this awareness lies usually on the fact that future teachers did not find this methodology in their own pre-service training. In this paper we will describe the attempt to introduce PBL in University courses so to have future maths teacher ``experience mathematics'' themselves.
Mathematical model of non-isothermal creep based anisotropic damage
Галаган, Ю. Н.; Лысенко, С. В.; Львов, Г. И.
2008-01-01
А mathematical model of nonisothermic creep for anisotropic damage case is considered. Constitutive relation of creep rate and kinematic equation of damage evolution are assumed temperature dependent. A second range tensor is used for description damage. A technique based on existing experimental curves for the identification of material creep constants is presented.
Discipline-Based Remediation: Bridging the Mathematics Gap
Wenner, Jennifer M.; Baer, Eric M.; Burn, Helen E.
2013-10-01
Geoscience relies on numbers, data, equations, graphical representations, and other quantitative skills; therefore, introductory geoscience courses need to accurately portray the science as quantitative [e.g., Wenner et al., 2009]. However, up to 57% of students arrive at college underprepared to perform mathematics at the level necessary to succeed in introductory courses [ACT, 2011]. Although some institutions have turned to prerequisites as a way to ensure appropriate preparation, these extra courses can place undue financial, temporal, and academic burdens on interested students, keeping them from enrolling in science courses that may interest them. As an alternative to mathematics prerequisites, geoscience faculty at the University of Wisconsin Oshkosh and Highline Community College in Des Moines, Wash., funded by the National Science Foundation, developed a model of successful integration of discipline-based mathematics remediation into an introductory geoscience course: The Math You Need, When You Need It (TMYN; http://serc.carleton.edu/mathyouneed/).
Palinussa, Anderson L.
2013-01-01
This paper presents the findings of a quasi-experimental with pre-test-post-test design and control group that aims to assess students' critical mathematical thinking skills and character through realistic mathematics education (RME) culture-based. Subjects of this study were 106 junior high school students from two low and medium schools level in…
A mathematical model for targeting chemicals to tissues by exploiting complex degradation
Directory of Open Access Journals (Sweden)
Grodzinsky Alan J
2011-09-01
Full Text Available Abstract Background In many biological and therapeutic contexts, it is highly desirable to target a chemical specifically to a particular tissue where it exerts its biological effect. In this paper, we present a simple, generic, mathematical model that elucidates a general method for targeting a chemical to particular tissues. The model consists of coupled reaction-diffusion equations to describe the evolution within the tissue of the concentrations of three chemical species: a (concentration of free chemical, b (binding protein and their complex, c (chemical bound to binding protein. We assume that all species are free to diffuse, and that a and b undergo a reversible reaction to form c. In addition, the complex, c, can be broken down by a process (e.g. an enzyme in the tissue that results in the release of the chemical, a, which is then free to exert its biological action. Results For simplicity, we consider a one-dimensional geometry. In the special case where the rate of complex formation is small (compared to the diffusion timescale of the species within the tissue the system can be solved analytically. This analytic solution allows us to show how the concentration of free chemical, a, in the tissue can be increased over the concentration of free chemical at the tissue boundary. We show that, under certain conditions, the maximum concentration of a can occur at the centre of the tissue, and give an upper bound on this maximum level. Numerical simulations are then used to determine how the behaviour of the system changes when the assumption of negligible complex formation rate is relaxed. Conclusions We have shown, using our mathematical model, how complex degradation can potentially be exploited to target a chemical to a particular tissue, and how the level of the active chemical depends on factors such as the diffusion coefficients and degradation/production rates of each species. The biological significance of these results in terms of
Semantic Web Based Efficient Search Using Ontology and Mathematical Model
Directory of Open Access Journals (Sweden)
K.Palaniammal
2014-01-01
Full Text Available The semantic web is the forthcoming technology in the world of search engine. It becomes mainly focused towards the search which is more meaningful rather than the syntactic search prevailing now. This proposed work concerns about the semantic search with respect to the educational domain. In this paper, we propose semantic web based efficient search using ontology and mathematical model that takes into account the misleading, unmatched kind of service information, lack of relevant domain knowledge and the wrong service queries. To solve these issues in this framework is designed to make three major contributions, which are ontology knowledge base, Natural Language Processing (NLP techniques and search model. Ontology knowledge base is to store domain specific service ontologies and service description entity (SDE metadata. The search model is to retrieve SDE metadata as efficient for Education lenders, which include mathematical model. The Natural language processing techniques for spell-check and synonym based search. The results are retrieved and stored in an ontology, which in terms prevents the data redundancy. The results are more accurate to search, sensitive to spell check and synonymous context. This paper reduces the user’s time and complexity in finding for the correct results of his/her search text and our model provides more accurate results. A series of experiments are conducted in order to respectively evaluate the mechanism and the employed mathematical model.
Wardono; Waluya, S. B.; Mariani, Scolastika; Candra D, S.
2016-02-01
This study aims to find out that there are differences in mathematical literacy ability in content Change and Relationship class VII Junior High School 19, Semarang by Problem Based Learning (PBL) model with an Indonesian Realistic Mathematics Education (called Pendidikan Matematika Realistik Indonesia or PMRI in Indonesia) approach assisted Elearning Edmodo, PBL with a PMRI approach, and expository; to know whether the group of students with learning PBL models with PMRI approach and assisted E-learning Edmodo can improve mathematics literacy; to know that the quality of learning PBL models with a PMRI approach assisted E-learning Edmodo has a good category; to describe the difficulties of students in working the problems of mathematical literacy ability oriented PISA. This research is a mixed methods study. The population was seventh grade students of Junior High School 19, Semarang Indonesia. Sample selection is done by random sampling so that the selected experimental class 1, class 2 and the control experiment. Data collected by the methods of documentation, tests and interviews. From the results of this study showed average mathematics literacy ability of students in the group PBL models with a PMRI approach assisted E-learning Edmodo better than average mathematics literacy ability of students in the group PBL models with a PMRI approach and better than average mathematics literacy ability of students in the expository models; Mathematics literacy ability in the class using the PBL model with a PMRI approach assisted E-learning Edmodo have increased and the improvement of mathematics literacy ability is higher than the improvement of mathematics literacy ability of class that uses the model of PBL learning with PMRI approach and is higher than the improvement of mathematics literacy ability of class that uses the expository models; The quality of learning using PBL models with a PMRI approach assisted E-learning Edmodo have very good category.
Filler segmentation of SEM paper images based on mathematical morphology.
Ait Kbir, M; Benslimane, Rachid; Princi, Elisabetta; Vicini, Silvia; Pedemonte, Enrico
2007-07-01
Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators. PMID:17867540
Image Filtering Based on Mathematical Morphology and Visual Perception Principle
Institute of Scientific and Technical Information of China (English)
JINGXiaojun; YUNong; SHANGYong
2004-01-01
The operation of a morphological filter can be divided into two basic problems that include morphological operation and Structuring element (SE) selection. The rules for morphological operations are predefined, so the filter's properties depend merely on the selection of SE. How to design adaptively the optimal morphological filter so as to automatically and delicately complete the tasks of target detection and recognition, becomes one of the current research hotspots and subtle technical problems. Based on the filtering theory of the mathematical morphology, by introducing appropriate visual perception principle, this paper presents how to design the filtering architecture and its target detection model through the optimal parameter training. By this way it can provide good detection results and robust adaptability to image targets with clutter background. It is sure to provide a new approach to automatic target recognition with mathematical morphology theory.
Engaging Future Teachers in Problem-Based Learning with the Park City Mathematics Institute Problems
Pilgrim, Mary E.
2014-01-01
Problem-based learning (PBL) is a pedagogical technique recommended for K-12 mathematics classrooms. However, the mathematics courses in future teachers' degree programs are often lecture based. Students typically learn about problem-based learning in theory, but rarely get to experience it first-hand in their mathematics courses. The premise…
DEFF Research Database (Denmark)
Kiil, Søren
2011-01-01
A mathematical model, describing the curing behaviour of a two-component, solvent-based, thermoset coating, is used to conduct a parameter study. The model includes curing reactions, solvent intra-film diffusion and evaporation, film gelation, vitrification, and crosslinking. A case study with a...... concentration of solvent. Simulations of solvent evaporation are compared to experimental data from a previous investigation. As part of the parameter study, mechanisms of this complex coating system are discussed....
Modelling Amperometric Biosensors Based on Chemically Modified Electrodes
Baronas, Romas; Kulys, Juozas
2008-01-01
The response of an amperometric biosensor based on a chemically modified electrode was modelled numerically. A mathematical model of the biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments: an enzyme layer and an outer diffusion layer. In order to define the main governing parameters the corresponding dimensionless mathematical model was derived. The digital simulation was carried out using the finite difference technique. The adequacy of the model was evaluated using analytical solutions known for very specific cases of the model parameters. By changing model parameters the output results were numerically analyzed at transition and steady state conditions. The influence of the substrate and mediator concentrations as well as of the thicknesses of the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially when the biosensor acts under a mixed limitation of the diffusion and the enzyme interaction with the substrate.
PREFACE: Physics-Based Mathematical Models for Nanotechnology
Voon, Lok C. Lew Yan; Melnik, Roderick; Willatzen, Morten
2008-03-01
stain-resistant clothing, but with thousands more anticipated. The focus of this interdisciplinary workshop was on determining what kind of new theoretical and computational tools will be needed to advance the science and engineering of nanomaterials and nanostructures. Thanks to the stimulating environment of the BIRS, participants of the workshop had plenty of opportunity to exchange new ideas on one of the main topics of this workshop—physics-based mathematical models for the description of low-dimensional semiconductor nanostructures (LDSNs) that are becoming increasingly important in technological innovations. The main objective of the workshop was to bring together some of the world leading experts in the field from each of the key research communities working on different aspects of LDSNs in order to (a) summarize the state-of-the-art models and computational techniques for modeling LDSNs, (b) identify critical problems of major importance that require solution and prioritize them, (c) analyze feasibility of existing mathematical and computational methodologies for the solution of some such problems, and (d) use some of the workshop working sessions to explore promising approaches in addressing identified challenges. With the possibility of growing practically any shape and size of heterostructures, it becomes essential to understand the mathematical properties of quantum-confined structures including properties of bulk states, interface states, and surface states as a function of shape, size, and internal strain. This workshop put strong emphasis on discussions of the new mathematics needed in nanotechnology especially in relation to geometry and material-combination optimization of device properties such as electronic, optical, and magnetic properties. The problems that were addressed at this meeting are of immense importance in determining such quantum-mechanical properties and the group of invited participants covered very well all the relevant disciplines
Indian Academy of Sciences (India)
Aldona Krupska
2015-06-01
In this paper the arduous attempt to find a mathematical solution for the nonlinear autocatalytic chemical processes with a time-varying and oscillating inflow of reactant to the reaction medium has been taken. Approximate analytical solution is proposed. Numerical solutions and analytical attempts to solve the non-linear differential equation indicates a phase shift between the oscillatory influx of intermediate reaction reagent to the medium of chemical reaction and the change of its concentration in this medium. Analytical solutions indicate that this shift may be associated with the reaction rate constants 1 and 2 and the relaxation time . The relationship between the phase shift and the oscillatory flow of reactant seems to be similar to that obtained in the case of linear chemical reactions, as described previously, however, the former is much more complex and different. In this paper, we would like to consider whether the effect of forced phase shift in the case of nonlinear and non-oscillatory chemical processes occurring particularly in the living systems have a practical application in laboratory.
Ottmar, Erin R.; Rimm-Kaufman, Sara E.; Larsen, Ross A.; Berry, Robert Q.
2015-01-01
This study investigates the effectiveness of the Responsive Classroom (RC) approach, a social and emotional learning intervention, on changing the relations between mathematics teacher and classroom inputs (mathematical knowledge for teaching [MKT] and standards-based mathematics teaching practices) and student mathematics achievement. Work was…
Anderson L. Palinussa
2013-01-01
This paper presents the findings of a quasi-experimental with pre-testpost-test design and control group that aims to assess students’ critical mathematical thinking skills and character through realisticmathematics education (RME) culture-based. Subjects of this studywere 106 junior high school students from two low and medium schools level in Ambon. The instruments of the study are: students’ early math skills test, critical thinking skills mathematical test and perception scale of students...
Mathematical model for light scanning system based on circular laser
Institute of Scientific and Technical Information of China (English)
Peiquan Xu; Shun Yao; Fenggui Lu; Xinhua Tang; Wei Zhang
2005-01-01
A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built.This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams,escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in "spot" or "line" type laser trajectory. Three-dimensional (3D) model for welded seams could be recognized after depth recovery. The imaging error is investigated also.
Nonlinear State Estimation with Missing Observations Based on Mathematical Programming
Czech Academy of Sciences Publication Activity Database
Pavelková, Lenka
Praha : ÚTIA AV ČR, 2010 - (Janžura, M.; Ivánek, J.). s. 23-23 [6th International Workshop on Data – Algorithms – Decision Making. 02.12.2010-04.12.2010, Jindřichův Hradec] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : state filtering * bounded errors * missing measurements Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2010/AS/pavelkova-nonlinear state estimation with missing observations based on mathematical programming .pdf
Inquiry-based mathematics teaching: The case of Célia.
Menezes, Luis; Oliveira, Hélia; Canavarro, Ana Paula
2015-01-01
This chapter discusses the instructional practice of a primary school teacher. It is based on a framework that we developed in the project “Professional Practices of Mathematics Teachers”, which relates the teacher’s intentions to her actions in an inquiry-based mathematics classroom. The framework covers the promotion of mathematics learning as well as the class management. It details the instructional actions of the teacher in terms of the launching of the mathematical tas...
A cellular automata-based mathematical model for thymocyte development.
Directory of Open Access Journals (Sweden)
Hallan Souza-e-Silva
Full Text Available Intrathymic T cell development is an important process necessary for the normal formation of cell-mediated immune responses. Importantly, such a process depends on interactions of developing thymocytes with cellular and extracellular elements of the thymic microenvironment. Additionally, it includes a series of oriented and tunely regulated migration events, ultimately allowing mature cells to cross endothelial barriers and leave the organ. Herein we built a cellular automata-based mathematical model for thymocyte migration and development. The rules comprised in this model take into account the main stages of thymocyte development, two-dimensional sections of the normal thymic microenvironmental network, as well as the chemokines involved in intrathymic cell migration. Parameters of our computer simulations with further adjusted to results derived from previous experimental data using sub-lethally irradiated mice, in which thymus recovery can be evaluated. The model fitted with the increasing numbers of each CD4/CD8-defined thymocyte subset. It was further validated since it fitted with the times of permanence experimentally ascertained in each CD4/CD8-defined differentiation stage. Importantly, correlations using the whole mean volume of young normal adult mice revealed that the numbers of cells generated in silico with the mathematical model fall within the range of total thymocyte numbers seen in these animals. Furthermore, simulations made with a human thymic epithelial network using the same mathematical model generated similar profiles for temporal evolution of thymocyte developmental stages. Lastly, we provided in silico evidence that the thymus architecture is important in the thymocyte development, since changes in the epithelial network result in different theoretical profiles for T cell development/migration. This model likely can be used to predict thymocyte evolution following therapeutic strategies designed for recovery of the
Unraveling the Culture of the Mathematics Classroom: A Video-Based Study in Sixth Grade
Depaepe, Fien; De Corte, Erik; Verschaffel, Lieven
2007-01-01
Changing perspectives on mathematics teaching and learning resulted in a new generation of mathematics textbooks, stressing among others the importance of mathematical reasoning and problem-solving skills and their application to real-life situations. The article reports a study that investigates to what extent the reform-based ideas underlying…
A MATLAB-Aided Method for Teaching Calculus-Based Business Mathematics
Liang, Jiajuan; Pan, William S. Y.
2009-01-01
MATLAB is a powerful package for numerical computation. MATLAB contains a rich pool of mathematical functions and provides flexible plotting functions for illustrating mathematical solutions. The course of calculus-based business mathematics consists of two major topics: 1) derivative and its applications in business; and 2) integration and its…
Yüksel, Ismail
2014-01-01
The aim of this paper is to examine the impact of activity-based mathematics instruction on mathematics performance and investigate those factors, which contribute to the mathematics performance of a sample of children aged between 10 and 12 years. The study was designed to consider the impact of prior knowledge, self-regulation, prior attitude,…
Butkovich, Nancy J.
2015-01-01
Doctoral candidates may request short-term embargoes on the release of their dissertations in order to apply for patents. This study examines how often inventions described in dissertations in chemical engineering, chemistry, physics, and mathematics are converted into U.S. patent applications, as well as the relationship between dissertation…
Nanotube-Based Chemical and Biomolecular Sensors
Institute of Scientific and Technical Information of China (English)
J.Koh; B.Kim; S.Hong; H.Lim; H.C.Choi
2008-01-01
We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomolecular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) process or "surface programmed assembly" method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.
Mathematical Biology Modules Based on Modern Molecular Biology and Modern Discrete Mathematics
Robeva, Raina; Davies, Robin; Hodge, Terrell; Enyedi, Alexander
2010-01-01
We describe an ongoing collaborative curriculum materials development project between Sweet Briar College and Western Michigan University, with support from the National Science Foundation. We present a collection of modules under development that can be used in existing mathematics and biology courses, and we address a critical national need to…
Directory of Open Access Journals (Sweden)
Marković Jelena Đ.
2009-01-01
Full Text Available Membrane process efficiency in the dairy industry is impaired by the formation of deposits during filtration processes. This work describes cleaning procedures for ceramic tubular membrane (50 nm fouled with whey proteins. Also, mathematical modelling was performed to obtain models which allow deeper insight into the mechanisms involved during cleaning procedures. The caustic solutions (0.2%w/w, 0.4%w/w and 1.0%w/w NaOH and the mixture of two commercial detergents (0.8%w/w P3-ultrasil 69+0.5% w/w P3-ultrasil 67 and 1.2% P3-ultrasil 69+0.75 P3-ultrasil 67 were used as chemical cleaning agents. The results showed that the best flux recovery was achieved with 0.4%w/w NaOH solution. After analyzing the experimental data, five parameter and six parameter kinetic models were suggested for alkali and detergent cleaning, respectively. The changes of total and specific resistances, as well as the change of the effective pore diameter and deposit thickness during cleaning are estimated by applying these models.
Computer-Based Mathematics Instructions for Engineering Students
Khan, Mustaq A.; Wall, Curtiss E.
1996-01-01
Almost every engineering course involves mathematics in one form or another. The analytical process of developing mathematical models is very important for engineering students. However, the computational process involved in the solution of some mathematical problems may be very tedious and time consuming. There is a significant amount of mathematical software such as Mathematica, Mathcad, and Maple designed to aid in the solution of these instructional problems. The use of these packages in classroom teaching can greatly enhance understanding, and save time. Integration of computer technology in mathematics classes, without de-emphasizing the traditional analytical aspects of teaching, has proven very successful and is becoming almost essential. Sample computer laboratory modules are developed for presentation in the classroom setting. This is accomplished through the use of overhead projectors linked to graphing calculators and computers. Model problems are carefully selected from different areas.
Keyword and image-based retrieval of mathematical expressions
Zanibbi, Richard; Yuan, Bo
2011-01-01
Two new methods for retrieving mathematical expressions using conventional keyword search and expression images are presented. An expression-level TF-IDF (term frequency-inverse document frequency) approach is used for keyword search, where queries and indexed expressions are represented by keywords taken from LATEX strings. TF-IDF is computed at the level of individual expressions rather than documents to increase the precision of matching. The second retrieval technique is a form of Content-Based Image Retrieval (CBIR). Expressions are segmented into connected components, and then components in the query expression and each expression in the collection are matched using contour and density features, aspect ratios, and relative positions. In an experiment using ten randomly sampled queries from a corpus of over 22,000 expressions, precision-at-k (k = 20) for the keyword-based approach was higher (keyword: μ = 84.0, σ = 19.0, imagebased: μ = 32.0, σ = 30.7), but for a few of the queries better results were obtained using a combination of the two techniques.
Hodges, Thomas E.; Jong, Cindy
2014-01-01
The authors drew upon Remillard and Bryans' categorization of curriculum use in observating two middle-grade teachers' integration of Standards-based curriculum materials produced by the National Council of Teachers of Mathematics. Each teacher participated in a two-year professional development program focused on increasing content knowledge and…
Smith, Glenn Gordon; Ferguson, David; Caris, Mieke
2003-01-01
This study examined the instructor experience of teaching college courses (discussion-based and mathematics) over the Web, versus in the classroom, in terms of teaching, social issues, and emergent issues such as media effects. We interviewed, by e-mail and telephone, 22 college instructors who taught in both formats. We categorized interview…
Material Encounters with Mathematics: The Case for Museum Based Cross-Curricular Integration
de Freitas, Elizabeth; Bentley, Sean J.
2012-01-01
This paper reports on research from a network of high school and museum partnerships designed to explore techniques for integrating mathematics and physics learning experiences during the first year of high school. The foundation of the curriculum is a problem-based, museum-based, and hands-on approach to mathematics and physics. In this paper, we…
Mathematical model for flood routing based on cellular automaton
Directory of Open Access Journals (Sweden)
Xin CAI
2014-04-01
Full Text Available Increasing frequency and severity of flooding have caused tremendous damage in China, requiring more essential countermeasures to alleviate the damage. In this study, the dynamic simulation property of a cellular automaton was used to make further progress in flood routing. In consideration of terrain’s influence on flood routing, we regarded the terrain elevation as an auxiliary attribute of a two-dimensional cellular automaton in path selection for flood routing and developed a mathematical model based on a cellular automaton. A numerical case of propagation of an outburst flood in an area of the lower Yangtze River was analyzed with both the fixed-step and variable-step models. The results show that the flood does not spread simultaneously in all directions, but flows into the lower place first, and that the submerged area grows quickly at the beginning, but slowly later on. The final submerged areas obtained from the two different models are consistent, and the flood volume balance test shows that the flood volume meets the requirement of the total volume balance. The analysis of the case shows that the proposed model can be a valuable tool for flood routing.
Potential Accessibility of Web-based mathematical information resources
Centelles Velilla, Miquel; Ribera, Mireia; Rodríguez Santiago, Inmaculada
2014-01-01
This paper presents a research concerning the conversion of non-accessible web pages containing mathematical formulae into accessible versions through an OCR (Optical Character Recognition) tool. The objective of this research is twofold. First, to establish criteria for evaluating the potential accessibility of mathematical web sites, i.e. the feasibility of converting non-accessible (non-MathML) math sites into accessible ones (Math-ML). Second, to propose a data model and a mechanism to pu...
The mathematical investigation of the work of enzyme biosensors based on conductive polymers
Valentynovych Tkach, Volodymyr; Vasyl´ovych Nechyporuk, Vasyl´; Ivanovych Yagodynets, Petro
2012-01-01
The work of CP-based biosensors was described mathematically in potentiostatic and potentiodynamic mode with constant voltage was mathematically described. The mathematical models were analyzed by linear-stability theory and bifurcation analysis. The stable-state conditions were derived by using the stable-state requirements for 2-dimensional systems (for the potentiostatic mode) and Routh-Hurwitz criterion (for the potentiodynamic mode). The causes for the oscillatory behavior are the influe...
Modelling Amperometric Biosensors Based on Chemically Modified Electrodes
Directory of Open Access Journals (Sweden)
Juozas Kulys
2008-08-01
Full Text Available The response of an amperometric biosensor based on a chemically modified electrode was modelled numerically. A mathematical model of the biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments: an enzyme layer and an outer diffusion layer. In order to define the main governing parameters the corresponding dimensionless mathematical model was derived. The digital simulation was carried out using the finite difference technique. The adequacy of the model was evaluated using analytical solutions known for very specific cases of the model parameters. By changing model parameters the output results were numerically analyzed at transition and steady state conditions. The influence of the substrate and mediator concentrations as well as of the thicknesses of the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially when the biosensor acts under a mixed limitation of the diffusion and the enzyme interaction with the substrate.
Design of greenbelt for an industrial complex based on mathematical modelling.
Khan, F I; Abbasi, S A
2002-07-01
Greenbelt is a strip of vegetation for which species of trees and shrubs are scientifically chosen and planted to serve a designated purpose such as control of wind erosion, of dust, of noise etc. In the context of air pollution attenuation, greenbelts must be developed around a source of air pollutant in a manner so as to effectively reduce the pollution caused by that source. Design of effective greenbelts involves consideration of meteorological, physico-chemical, biological, and horticultural aspects relevant to pollutant source and the area where greenbelt has to be established. These authors have recently developed mathematical models for effective design of greenbelts. This paper presents an overview of the methodology based on the models, and describes a case study in which the methodology has been applied to design a greenbelt for a real-life situation. PMID:12164640
Directory of Open Access Journals (Sweden)
Edwin Musdi
2016-02-01
Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase. At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.
Development and Evaluation of Consumer-Based Mathematics Materials in Adult Basic Education.
Campbell, Patricia F.; Kulm, Gerald
1980-01-01
In creating mathematics materials for adult basic education students, researchers (1) interviewed students and teachers to determine needs and objectives; (2) developed materials based on consumer mathematics skills; and (3) evaluated effectiveness by a pretest/posttest and student, teacher, and administrator questionnaires. Results showed the…
Huang, Tzu-Hua; Liu, Yuan-Chen; Chang, Hsiu-Chen
2012-01-01
This study developed a computer-assisted mathematical problem-solving system in the form of a network instruction website to help low-achieving second- and third-graders in mathematics with word-based addition and subtraction questions in Taiwan. According to Polya's problem-solving model, the system is designed to guide these low-achievers…
Effect of Digital Game Based Learning on Ninth Grade Students' Mathematics Achievement
Swearingen, Dixie K.
2011-01-01
This experimental study examined the effect of an educational massive multiplayer online game (MMOG) on achievement on a standards-based mathematics exam. It also examined the interaction of student characteristics (gender and socioeconomic status) with digital game play on mathematics achievement. Two hundred eighty ninth grade students from a…
An Excel-Aided Method for Teaching Calculus-Based Business Mathematics
Liang, Jiajuan; Martin, Linda
2008-01-01
Calculus-based business mathematics is a required quantitative course for undergraduate business students in most AACSB accredited schools or colleges of business. Many business students, however, have relatively weak mathematical background or even display math-phobia when presented with calculus problems. Because of the popularity of Excel, its…
Directory of Open Access Journals (Sweden)
Alexey M. Lipanov
1997-10-01
Full Text Available In this paper, the laws of the unstable wave processes accompanying the combustion abnormal mode in the large-sized solid propellant rocket motor {SPRM pyrotechnical ignition system {IS are investigated by numerical method. The IS contains the main {cylindrical channel (MC having uniform perforation over the lateral surface, The left MC boundary is blocked and the right boundary is uniformly perforated. The whole perforation is hermetically sealed from outside. The additional {cylindrical channel {AC {an initial impulse amplifier with uniform perforation over the lateral surface is installed into the MC cavity, coaxially to MC. The right AC boundary is blocked, and the time-varying high-temperature gas flow, containing incandescent 'particles is supplied from initiator, equipped with a fast burning compound, through AC left perforated boundary. To imitate the exploitation conditions, the IS is placed in cylindrical imitation chamber {imitative SPRM. In a number of cases, before the beginning of the IS operation, a situation can be realised when the pelletised solid propellant {PSP mass is non-uniformly distributed along the IS AC length, and the greater part of the AC lateral perforation is blocked by the PSP inserted in the IS MC. Under these conditions, the effect of abnormal strengthening of the pressure waves at the AC boundaries is possible. For describing the abnormal nonstationary physico-chemical processes, a mathematical model is developed. For the check-up of this complex model, the numerical calculation results have been compared with the results of the fire stand tests for the regular IS and the engine. The numerical analysis of the unstable wave process development in the AC has shown that the rise of the pressure with an ever increasing amplitude is realised at the moment, when a shock wave reflects alternately, on the left and on the right AC boundaries. The effect of the pressure waves' abnormal strengthening can result in the
Use of PC Based Mathematics Software in the Undergraduate Curriculum.
Slaughter, Joseph M.; And Others
1991-01-01
Three mathematics software packages, MathCAD, Point Five, and TK Solver Plus, are described and compared. The packages were rated on the accompanying documentation, ease of learning, ease of use, matrix operations, equation solving capability, versatility, use of units, generation of graphs and tables, readability of output, and overall…
Chemical Sensors Based on Optical Ring Resonators
Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander
2005-01-01
Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong
Mathematical Modeling of Carcinogenesis Based on Chromosome Aberration Data
Institute of Scientific and Technical Information of China (English)
Xiao-bo Li
2009-01-01
Objective: The progression of human cancer is characterized by the accumulation of genetic instability. An increasing number of experimental genetic molecular techniques have been used to detect chromosome aberrations. Previous studies on chromosome abnormalities often focused on identifying the frequent loci of chromosome alterations, but rarely addressed the issue of interrelationship of chromosomal abnormalities. In the last few years, several mathematical models have been employed to construct models of carcinogenesis, in an attempt to identify the time order and cause-and-effect relationship of chromosome aberrations. The principles and applications of these models are reviewed and compared in this paper. Mathematical modeling of carcinogenesis can contribute to our understanding of the molecular genetics of tumor development, and identification of cancer related genes, thus leading to improved clinical practice of cancer.
A Library of OpenGL-Based Mathematical Image Filters
Von Gagern, Martin; Mercat, Christian
2010-01-01
There are a lot of transformations that can turn one raster image into a derived one in a mathematically interesting way. This article describes a collection of such filters, implemented in OpenGL in order to use the high degree of parallelism modern GPUs provide, thereby providing performance required to process e.g. live camera images in real-time. The filters contained in this library include wallpaper groups, conformal maps described by meromorphic functions, as well as hyperbolic symmetr...
Mathematical model of delay lines based on magnetostatic waves
Directory of Open Access Journals (Sweden)
E. V. Kudinov
2010-12-01
Full Text Available On the example of the delay line have demonstrated the possibility of applying the principle of decomposition to construct mathematical models of microwave devices using magnetostatic waves (MSW in a magnetized epitaxial ferrite films, which allows for a unified methodological basis and the lowest cost to the experimental optimization design of MSW devices for various applications
Mathematical model of delay lines based on magnetostatic waves
E. V. Kudinov
2010-01-01
On the example of the delay line have demonstrated the possibility of applying the principle of decomposition to construct mathematical models of microwave devices using magnetostatic waves (MSW) in a magnetized epitaxial ferrite films, which allows for a unified methodological basis and the lowest cost to the experimental optimization design of MSW devices for various applications
Mathematical Modeling of lndustrial Robots Based on Hamiltonian Mechanics
Czech Academy of Sciences Publication Activity Database
Záda, V.; Belda, Květoslav
Košice: Slovak Society for Applied Cybernetics and Informatics (SSAKI), 2016, s. 813-818. ISBN 978-1-4673-8606-7. [17th International Carpathian Control Conference (ICCC). Tatranská Lomnica (SK), 29.05.2016-01.06.2016] Institutional support: RVO:67985556 Keywords : Robot -manipulator * Hamiltonian formalism * mathematical modeling * PD control * model-oreinted motion control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2016/AS/belda-0459855.pdf
Amineborane Based Chemical Hydrogen Storage - Final Report
International Nuclear Information System (INIS)
The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also demonstrated
Carbon-Nanotube-Based Chemical Gas Sensor
Kaul, Arunpama B.
2010-01-01
Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.
Mathematical foundation of the optimization-based fluid animation method
DEFF Research Database (Denmark)
Erleben, Kenny; Misztal, Marek Krzysztof; Bærentzen, Jakob Andreas
2011-01-01
We present the mathematical foundation of a fluid animation method for unstructured meshes. Key contributions not previously treated are the extension to include diffusion forces and higher order terms of non-linear force approximations. In our discretization we apply a fractional step method to be...... stress tensor. Rather than applying a straightforward temporal finite difference method followed by a projection method to enforce incompressibility as done in the stable fluids method, the last step of the fractional step method is rewritten as an optimization problem to make it easy to incorporate non...
Hsu, Chun-Wei; Goh, Joshua O. S.
2016-01-01
When comparing between the values of different choices, human beings can rely on either more cognitive processes, such as using mathematical computation, or more affective processes, such as using emotion. However, the neural correlates of how these two types of processes operate during value-based decision-making remain unclear. In this study, we investigated the extent to which neural regions engaged during value-based decision-making overlap with those engaged during mathematical and emotional processing in a within-subject manner. In a functional magnetic resonance imaging experiment, participants viewed stimuli that always consisted of numbers and emotional faces that depicted two choices. Across tasks, participants decided between the two choices based on the expected value of the numbers, a mathematical result of the numbers, or the emotional face stimuli. We found that all three tasks commonly involved various cortical areas including frontal, parietal, motor, somatosensory, and visual regions. Critically, the mathematical task shared common areas with the value but not emotion task in bilateral striatum. Although the emotion task overlapped with the value task in parietal, motor, and sensory areas, the mathematical task also evoked responses in other areas within these same cortical structures. Minimal areas were uniquely engaged for the value task apart from the other two tasks. The emotion task elicited a more expansive area of neural activity whereas value and mathematical task responses were in more focal regions. Whole-brain spatial correlation analysis showed that valuative processing engaged functional brain responses more similarly to mathematical processing than emotional processing. While decisions on expected value entail both mathematical and emotional processing regions, mathematical processes have a more prominent contribution particularly in subcortical processes. PMID:27375466
Hsu, Chun-Wei; Goh, Joshua O S
2016-01-01
When comparing between the values of different choices, human beings can rely on either more cognitive processes, such as using mathematical computation, or more affective processes, such as using emotion. However, the neural correlates of how these two types of processes operate during value-based decision-making remain unclear. In this study, we investigated the extent to which neural regions engaged during value-based decision-making overlap with those engaged during mathematical and emotional processing in a within-subject manner. In a functional magnetic resonance imaging experiment, participants viewed stimuli that always consisted of numbers and emotional faces that depicted two choices. Across tasks, participants decided between the two choices based on the expected value of the numbers, a mathematical result of the numbers, or the emotional face stimuli. We found that all three tasks commonly involved various cortical areas including frontal, parietal, motor, somatosensory, and visual regions. Critically, the mathematical task shared common areas with the value but not emotion task in bilateral striatum. Although the emotion task overlapped with the value task in parietal, motor, and sensory areas, the mathematical task also evoked responses in other areas within these same cortical structures. Minimal areas were uniquely engaged for the value task apart from the other two tasks. The emotion task elicited a more expansive area of neural activity whereas value and mathematical task responses were in more focal regions. Whole-brain spatial correlation analysis showed that valuative processing engaged functional brain responses more similarly to mathematical processing than emotional processing. While decisions on expected value entail both mathematical and emotional processing regions, mathematical processes have a more prominent contribution particularly in subcortical processes. PMID:27375466
Mathematics achievement based on gender among eight grade school students in Jordan
Rabab'h, Belal Sadiq Hamed; Veloo, Arsaythamby; Perumal, Selvan
2015-05-01
The purpose of this study is to identify the differences in gender base on numbers, algebra, geometry and mathematics achievement among Jordanian 8th grade school students. The respondent of this study were 337 students from eight public secondary schools in Alkoura district and selected by using stratified random sampling. The study comprised of 179 (53%) males and 158 (47%) females students. The mathematics test comprises of 30 items which has eight items for numbers, 14 items for algebra and eight items for geometry. Finding from independent sample t-test shows that female student score higher than male students in numbers, algebra, mathematics achievement and spatial visualization. There is no significant difference in geometry base for gender. This study also indicates that numbers, algebra and mathematics achievement favorable to female and bias to male students. The main recommendations from this study are for teachers and other educational professionals to focus on the numbers and algebra for male students to improve the learning of mathematics, and feeding program through benefiting from tutorial classes to avoid of weakness in different aspects of mathematics achievement. Gender differences in mathematics in secondary school students in Jordan continue to exist and these differences may influence future educational and occupational pathways.
DiffGame: Game-based mathematics learning for physics
Pedersen, Mads Kock; Dohn, Niels Bonderup; Lieberoth, Andreas; Sherson, Jacob
2016-01-01
Differentiation is a mathematical skill applied throughout science in order to describe the change of a function with respect to a dependent variable. Thus, an intuitive understanding of differentiation is necessary to work with the mathematical frameworks used to describe physical systems in the higher levels of education. In order to obtain this intuition repeated practice is required. In this paper we present the development of DiffGame, which consists of a series of exercises that introduce the basic principles of differentiation for high-school students through game-like elements. DiffGame have been tested with 117 first-year students from a single Danish high school, who did not have any prior training in differentiation. The students' learning was assessed by the data obtained directly from DiffGame. The test demonstrated the efficacy of DiffGame, since students at all levels demonstrate a learning gain. In contrast to previous studies demonstrating most learning in the lower tier of students, we find ...
Analytical derivation: An epistemic game for solving mathematically based physics problems
Bajracharya, Rabindra R.; Thompson, John R.
2016-06-01
Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the analytical derivation game. This game involves deriving an equation through symbolic manipulations and routine mathematical operations, usually without any physical interpretation of the processes. This game often creates cognitive obstacles in students, preventing them from using alternative resources or better approaches during problem solving. We conducted hour-long, semi-structured, individual interviews with fourteen introductory physics students. Students were asked to solve four "pseudophysics" problems containing algebraic and graphical representations. The problems required the application of the fundamental theorem of calculus (FTC), which is one of the most frequently used mathematical concepts in physics problem solving. We show that the analytical derivation game is necessary, but not sufficient, to solve mathematically based physics problems, specifically those involving graphical representations.
A framework for designing a research-based "mathematics counsellor" teacher programme
DEFF Research Database (Denmark)
Niss, Mogens Allan; Thomas Jankvist, Uffe
2015-01-01
This article addresses one way in which decades of mathematics education research results can inform practice, by offering a framework for designing and implementing an in-service teacher education programme for upper secondary mathematics teachers in Denmark. The programme aims to educate a “task...... force” of so-called “maths counsellors”, i.e., mathematics teachers whose goal it is to help identify students with genuine learning difficulties in mathematics, investigate the nature of these difficulties, and carry out research-based interventions to assist the students in overcoming them. We present...... and discuss the various components of the programme, theoretical as well as practical, and account for how these make up a framework for designing a research-based “maths counsellor” teacher programme...
Math Play : growing and developing mathematics understanding in an emergent play-based environment
DeGroot, Kendra
2012-01-01
This project explores how mathematics growth and development can be supported, documented and assessed in an emergent play-based early childhood education environment inspired by the practices and principles of Reggio Emilia. Using the California Preschool Learning Foundations as a framework, Math Play includes developmentally appropriate activities and environments that support cognitive development within the mathematics domain. This curriculum documents how a classroom's emergent themes we...
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.
Chemical Sensors Based on Metal Oxide Nanostructures
Hunter, Gary W.; Xu, Jennifer C.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.; Kulis, Mike J.; Liu, Chung-Chiun
2006-01-01
This paper is an overview of sensor development based on metal oxide nanostructures. While nanostructures such as nanorods show significan t potential as enabling materials for chemical sensors, a number of s ignificant technical challenges remain. The major issues addressed in this work revolve around the ability to make workable sensors. This paper discusses efforts to address three technical barriers related t o the application of nanostructures into sensor systems: 1) Improving contact of the nanostructured materials with electrodes in a microse nsor structure; 2) Controling nanostructure crystallinity to allow co ntrol of the detection mechanism; and 3) Widening the range of gases that can be detected by using different nanostructured materials. It is concluded that while this work demonstrates useful tools for furt her development, these are just the beginning steps towards realizati on of repeatable, controlled sensor systems using oxide based nanostr uctures.
Opportunity-to-Learn Context-Based Tasks Provided by Mathematics Textbooks
Wijaya, Ariyadi; van den Heuvel-Panhuizen, Marja; Doorman, Michiel
2015-01-01
Based on the findings of an error analysis revealing that Indonesian ninth- and tenth-graders had difficulties in solving context-based tasks, we investigated the opportunity-to-learn offered by Indonesian textbooks for solving context-based mathematics tasks and the relation of this opportunity-to-learn to students' difficulties in solving these…
Directory of Open Access Journals (Sweden)
Johann Engelbrecht
2009-09-01
Full Text Available Following the political changes of 1994 in South Africa, the decision was taken to replace the traditional skills-based education system at primary and secondary school level (Grades 1 - 12 with an outcomes-based education system (OBE. The OBE approach, referred to as Curriculum 2005, was introduced into schools in 1998. The implementation of the OBE system did not occur without problems, giving rise to revised initiatives and a fair amount of criticism. The 2009 intake of students at universities is the ﬁrst group of students that had been subjected to the OBE approach for their entire school career. This is also the ﬁrst group of students for whom some form of mathematics was compulsory up to Grade 12 level in the form of mathematics or mathematical literacy. These students were characterised by the fact that their mathematics marks for Grade 12 were exceptionally high and that many more students qualiﬁed for university entrance. This article reports on the impact of this new education system on the mathematics prepared-ness of students entering university. The study involves an empirical analysis of the students in the ﬁrst-year mathematics course for engineering students at the University of Pretoria as well as an analysis of a questionnaire completed by experienced lecturers at this university. The question addressed in this article is how the 2009 intake of students cope with mathematics at university level with regard to Performance General attributes Mathematical attributes Content-related attributesResults indicate a decrease in mathematics performance of these students at university level and that the inﬂated matric marks result in unjustiﬁed expectations. However, it is not unusual for marks to decrease from school to university and there is still too little evidence for serious concern. The study also indicates that these students seem to be better equipped with regard to personal attributes such as self-conﬁdence and
Layout-based substitution tree indexing and retrieval for mathematical expressions
Schellenberg, Thomas; Yuan, Bo; Zanibbi, Richard
2012-01-01
We introduce a new system for layout-based (LATEX) indexing and retrieval of mathematical expressions using substitution trees. Substitution trees can efficiently store and find expressions based on the similarity of their symbols, symbol layout, sub-expressions and size. We describe our novel implementation and some of our modifications to the substitution tree indexing and retrieval algorithms. We provide an experiment testing our system against the TF-IDF keyword-based system of Zanibbi and Yuan and demonstrate that, in many cases, the quality of search results returned by both systems is comparable (overall means, substitution tree vs. keywordbased: 100% vs. 89% for top 1; 48% vs. 51% for top 5; 22% vs. 28% for top 20). Overall, we present a promising first attempt at layout-based substitution tree indexing and retrieval for mathematical expressions and believe that this method will prove beneficial to the field of mathematical information retrieval.
Mathematical thinking of maintenance. Problem setting and solving bases
International Nuclear Information System (INIS)
Plant or mechanical facility for maintenance became more complicated than before and consisted of many subsystems made of various equipments or facilities with parts, which were a system having complicated and hierarchical structure. Maintenance was required to be properly implemented to assure reliability of a system for a long period so as for each equipment to play a specified role for a stable operation of plant. Mathematical thinking using probability theory was rational to optimize maintenance action with failure rate function of system or part of equipment. Reliability function, maintainability function and availability of plant and equipment were defined. Unreliability function was called failure time distribution function (F(t)) and failure rate function (λ(t)) was defined as the ratio of failure time density distribution function (dF(t)/dt) to reliability function (1-F(t)). λ(t) could be expressed as a simple equation with Weibull parameter. Availability at steady state was attributed to ratio of average operating time to sum of operating time and maintenance time, i.e. MTBF/(MTBF+MTTR) where MTBF was mean time between failures and MTTR was mean time to repair. Optimization of system risk and maintenance action was encouraged using computational science simulating material degradation. (T. Tanaka)
Directory of Open Access Journals (Sweden)
Alexander B. Bakulev
2012-11-01
Full Text Available This article deals with mathematical models and algorithms, providing mobility of sequential programs parallel representation on the high-level language, presents formal model of operation environment processes management, based on the proposed model of programs parallel representation, presenting computation process on the base of multi-core processors.
Alexander B. Bakulev; Marina A. Bakuleva; Svetlana B. Avilkina
2012-01-01
This article deals with mathematical models and algorithms, providing mobility of sequential programs parallel representation on the high-level language, presents formal model of operation environment processes management, based on the proposed model of programs parallel representation, presenting computation process on the base of multi-core processors.
Discourses about School-Based Mathematics Teacher Education in Finland and Sweden
Ryve, Andreas; Hemmi, Kirsti; Borjesson, Mats
2013-01-01
In this cross-case study we focus on school-based teacher education in Sweden and Finland. Through the use of focus-group interviews with mathematics teacher educators in Finland and Sweden, the study shows that there are substantial differences in how school-based teacher education is introduced and portrayed in the discourse about teacher…
Data base of chemical explosions in Kazakhstan
Energy Technology Data Exchange (ETDEWEB)
Demin, V.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Malahova, M.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Martysevich, P.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Mihaylova, N.N. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Nurmagambetov, A. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Kopnichev, Yu.F. D. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan); Edomin, V.I. [National Nuclear Center of Republic of Kazakhstan Institute of Geophysical Researches (Kazakhstan)
1996-12-01
Within the bounds of this report, the following works were done: (1) Information about explosion quarries, located in Southern, Eastern and Northern Kasakstan was summarized. (2) The general information about seismicity of areas of location of explosion quarries was adduced. (3) The system of observation and seismic apparatus, recording the local earthquakes and quarry explosions at the territory of Kazakstan were described. (4) Data base of quarry explosions, that were carried out in Southern, Eastern and Northern Kazakstan during 1995 and first half of 1996 year was adduced. (5) Upon the data of registration of explosions in Southern Kazakstan the correlative dependences between power class of explosions and summary weight of charge were constructed. (6) Seismic records of quarry explosions were adduced. It is necessary to note, that the collection of data about quarry explosions in Kazakstan in present time is very difficult task. Organizations, that makes these explosions, are always suffering reorganizations and sometimes it is actually impossible to receive all the necessary information. Some quarries are situated in remote, almost inaccessible regions, and within the bounds of supplier financing not the every quarry was in success to visit. So the present data base upon the chemical explosions for 1995 is not full and in further it`s expansion is possible.
DEFF Research Database (Denmark)
Rees, Stephen Edward; Rychwicka-Kielek, Beate A; Andersen, Bjarne F;
2012-01-01
Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission for exacerbat......Abstract Background: Repeated arterial puncture is painful. A mathematical method exists for transforming peripheral venous pH, PCO2 and PO2 to arterial eliminating the need for arterial sampling. This study evaluates this method to monitor acid-base and oxygenation during admission...
der Schaft, Arjan van; Rao, Shodhan; Jayawardhana, Bayu
2011-01-01
Motivated by recent progress on the interplay between graph theory, dynamics, and systems theory, we revisit the analysis of chemical reaction networks described by mass action kinetics. For reaction networks possessing a thermodynamic equilibrium we derive a compact formulation exhibiting at the same time the structure of the complex graph and the stoichiometry of the network, and which admits a direct thermodynamical interpretation. This formulation allows us to easily characterize the set ...
Mathematical design of prokaryotic clone-based microarrays
Pieterse, B.; Quirijns, E.J.; Schuren, F.H.J.; Werf, M.J. van der
2005-01-01
Background: Clone-based microarrays, on which each spot represents a random genomic fragment, are a good alternative to open reading frame-based microarrays, especially for microorganisms for which the complete genome sequence is not available. Since the generation of a genomic DNA library is a rand
Directory of Open Access Journals (Sweden)
Reviandari Widyatiningtyas
2015-07-01
Full Text Available The study was report the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students’ prior mathematical ability to student’s mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from excellent and moderate school level. The research instruments a set of mathematical critical thinking ability test, and the data were analyzed by using two ways ANOVA and t-test. The research found that the problem based learning approach has significant impact to the ability of students’ mathematics critical thinking in terms of school level and students’ prior mathematical abilities. Furthermore. This research also found that there is no interaction between learning approach and school level, and learning approach and students’ prior mathematics ability to students’ mathematics critical thinking ability.
Mathematical Modelling of a Hybrid Micro-Cogeneration Group Based on a Four Stroke Diesel Engine
Directory of Open Access Journals (Sweden)
Apostol Valentin
2014-06-01
Full Text Available The paper presents a part of the work conducted in the first stage of a Research Grant called ”Hybrid micro-cogeneration group of high efficiency equipped with an electronically assisted ORC” acronym GRUCOHYB. The hybrid micro-cogeneration group is equipped with a four stroke Diesel engine having a maximum power of 40 kW. A mathematical model of the internal combustion engine is presented. The mathematical model is developed based on the Laws of Thermodynamics and takes into account the real, irreversible processes. Based on the mathematical model a computation program was developed. The results obtained were compared with those provided by the Diesel engine manufacturer. Results show a very high correlation between the manufacturer’s data and the simulation results for an engine running at 100% load. Future developments could involve using an exergetic analysis to show the ability of the ORC to generate electricity from recovered heat
Applying Mathematical Optimization Methods to an ACT-R Instance-Based Learning Model
Said, Nadia; Engelhart, Michael; Kirches, Christian; Körkel, Stefan; Holt, Daniel V.
2016-01-01
Computational models of cognition provide an interface to connect advanced mathematical tools and methods to empirically supported theories of behavior in psychology, cognitive science, and neuroscience. In this article, we consider a computational model of instance-based learning, implemented in the ACT-R cognitive architecture. We propose an approach for obtaining mathematical reformulations of such cognitive models that improve their computational tractability. For the well-established Sugar Factory dynamic decision making task, we conduct a simulation study to analyze central model parameters. We show how mathematical optimization techniques can be applied to efficiently identify optimal parameter values with respect to different optimization goals. Beyond these methodological contributions, our analysis reveals the sensitivity of this particular task with respect to initial settings and yields new insights into how average human performance deviates from potential optimal performance. We conclude by discussing possible extensions of our approach as well as future steps towards applying more powerful derivative-based optimization methods. PMID:27387139
Chemical sensors based on the modification of a resonator cavity
Hennig, Oliver; Mendes, Sergio B.; Fallahi, Mahmoud; Peyghambarian, Nasser
1999-02-01
In this paper, we present a chemical sensor based on the modification of an optical resonator: the optical path length of the resonant cavity is changed by the chemical in question, thus shifting its resonant frequency.
Developing Teaching Materials PISA-Based for Mathematics and Science of Junior High School
Somakim; Suharman, Andi; Madang, Kodri; Taufiq
2016-01-01
This research aims to develop valid and practical teaching materials for mathematics and science lesson PISA-based for junior high school students and to determine potential effects on students in scientific activity. Subjects of this study were students of Junior High School 9 Palembang (SMP Negeri 9 Palembang). The method used in this study is…
Hongli Liu; Xiong Zhou; Lei Xiao
2012-01-01
Adopting the microscopic observation imaging and digital image processing technologies, this paper researches a new measuring method of indoor inhalable particulate matter concentration and size distribution .It realizes denoising, binarization, filtering and edge detection to based on mathematical morphology, regional filled and calibration detection to particulate matter image, designs the parameters recognition algorithm for particulate matter size, fractal dimension ,shape factors and so ...
Modeling Zombie Outbreaks: A Problem-Based Approach to Improving Mathematics One Brain at a Time
Lewis, Matthew; Powell, James A.
2016-01-01
A great deal of educational literature has focused on problem-based learning (PBL) in mathematics at the primary and secondary level, but arguably there is an even greater need for PBL in college math courses. We present a project centered around the Humans versus Zombies moderated tag game played on the Utah State University campus. We discuss…
Analytical Derivation: An Epistemic Game for Solving Mathematically Based Physics Problems
Bajracharya, Rabindra R.; Thompson, John R.
2016-01-01
Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the "analytical derivation" game. This game involves deriving an…
Assessing Long-Term Effects of Inquiry-Based Learning: A Case Study from College Mathematics
Kogan, Marina; Laursen, Sandra L.
2014-01-01
As student-centered approaches to teaching and learning are more widely applied, researchers must assess the outcomes of these interventions across a range of courses and institutions. As an example of such assessment, this study examined the impact of inquiry-based learning (IBL) in college mathematics on undergraduates' subsequent grades…
Incikabi, Lutfi; Sancar Tokmak, Hatice
2012-01-01
This case study examined the educational software evaluation processes of pre-service teachers who attended either expertise-based training (XBT) or traditional training in conjunction with a Software-Evaluation checklist. Forty-three mathematics teacher candidates and three experts participated in the study. All participants evaluated educational…
Petersen, Richard H.
1997-01-01
The objectives of the Institute were: (a) increase participants' content knowledge about aeronautics, science, mathematics, and technology, (b) model and promote the use of scientific inquiry through problem-based learning, (c) investigate the use of instructional technologies and their applications to curricula, and (d) encourage the dissemination of TEI experiences to colleagues, students, and parents.
Mathematics Achievement with Digital Game-Based Learning in High School Algebra 1 Classes
Ferguson, Terri Lynn Kurley
2014-01-01
This study examined the impact of digital game-based learning (DGBL) on mathematics achievement in a rural high school setting in North Carolina. A causal comparative research design was used in this study to collect data to determine the effectiveness of DGBL in high school Algebra 1 classes. Data were collected from the North Carolina…
Exploring the Impact of Web-Based Learning Tools in Middle School Mathematics and Science Classrooms
Kay, Robin
2011-01-01
This study examines the impact of Web-Based Learning Tools (WBLTs), also known as learning objects, in middle school mathematics and science classrooms. Survey, qualitative, and student performance data were collected from a sample of 18 teachers and 443 students. Teachers were very positive about the learning benefits, quality of WBLTs, and…
Effects of Computer-Based Visual Representation on Mathematics Learning and Cognitive Load
Yung, Hsin I.; Paas, Fred
2015-01-01
Visual representation has been recognized as a powerful learning tool in many learning domains. Based on the assumption that visual representations can support deeper understanding, we examined the effects of visual representations on learning performance and cognitive load in the domain of mathematics. An experimental condition with visual…
Using GIS to Teach Place-Based Mathematics in Rural Classrooms
Leonard, Jacqueline; Russell, Nicole M.; Hobbs, Robert M.; Buchanan, Heather
2013-01-01
The purpose of this article is to promote the use of GIS and place-based education (PBE) in rural mathematics classrooms. The pedagogy of place is disappearing from rural communities because of declining enrollments, lack of support, and federal mandates to focus more on basic academic skills. However, PBE does not stand in opposition to…
An Analysis of the Competency-Based Secondary Mathematics Curriculum in Sri Lanka
Egodawatte, Gunawardena
2014-01-01
In education, there is a growing interest in the concept of "competency" especially in vocational training and professional development. The concept is strongly associated with the ability to apply knowledge and skills in effective ways in unanticipated situations. In Sri Lanka, a new competency-based mathematics curriculum was…
Number-free Mathematics Based on T-norm Fuzzy Logic
Czech Academy of Sciences Publication Activity Database
Běhounek, Libor
Granada: EUSFLAT, 2009 - (Carvalho, J.; Dubois, D.; Kaymak, U.; Sousa, J.), s. 449-454 ISBN 978-989-95079-6-8. [IFSA - EUSFLAT 2009. International Fuzzy Systems Association World Congress 2009, European Society for Fuzzy Logic and Technology Conference 2009. Lisabon (PT), 20.07.2009-24.07.2009] R&D Projects: GA AV ČR IAA100300503 Institutional research plan: CEZ:AV0Z10300504 Keywords : Fuzzy Class Theory * fuzzy mathematics * fuzzy set * real -valued function * similarity-based limit * t-norm fuzzy logic Subject RIV: BA - General Mathematics
Gultepe, Nejla; Yalcin Celik, Ayse; Kilic, Ziya
2013-01-01
The purpose of the study was to examine the effects of students' conceptual understanding of chemical concepts and mathematical processing skills on algorithmic problem-solving skills. The sample (N = 554) included grades 9, 10, and 11 students in Turkey. Data were collected using the instrument "MPC Test" and with interviews. The…
A method of building information extraction based on mathematical morphology and multiscale
Li, Jing-wen; Wang, Ke; Zhang, Zi-ping; Xue, Long-li; Yin, Shou-qiang; Zhou, Song
2015-12-01
In view of monitoring the changes of buildings on Earth's surface ,by analyzing the distribution characteristics of building in remote sensing image, combined with multi-scale in image segmentation and the advantages of mathematical morphology, this paper proposes a multi-scale combined with mathematical morphology of high resolution remote sensing image segmentation method, and uses the multiple fuzzy classification method and the shadow of auxiliary method to extract information building, With the comparison of k-means classification, and the traditional maximum likelihood classification method, the results of experiment object based on multi-scale combined with mathematical morphology of image segmentation and extraction method, can accurately extract the structure of the information is more clear classification data, provide the basis for the intelligent monitoring of earth data and theoretical support.
Chamberlin, Michelle T.
2013-01-01
In a mathematics course for prospective elementary teachers, we strove to model standards-based pedagogy. However, an end-of-class reflection revealed the prospective teachers were considering incorporating standards-based strategies in their future classrooms in ways different from our intent. Thus, we drew upon the framework presented by Simon,…
Polymers based on chemically modified starch
Czech Academy of Sciences Publication Activity Database
Horák, Pavel; Kruliš, Zdeněk; Šárka, E.; Kobera, Libor
Prague : Czech Chemical Society, 2014 - (Řápková, R.; Čopíková, J.; Šárka, E.), s. 88-90 ISBN 978-80-86238-70-8. [International Conference on Polysaccharides-Glycoscience /10./. Prague (CZ), 22.10.2014-24.10.2014] R&D Projects: GA TA ČR(CZ) TA04020853 Institutional support: RVO:61389013 Keywords : starch * chemical modification * degree of substitution Subject RIV: CD - Macromolecular Chemistry
Xianjun Li; Yongfeng Luo; Hongbin Chen; Xia He; Jianxiong Lv; Yiqiang Wu
2013-01-01
High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nanocomposites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased al...
Directory of Open Access Journals (Sweden)
M. N. Modebelu
2014-04-01
Full Text Available This study aimed at determining the effect of reform-based-instructional method learning styles on students’ achievement and retention in mathematics. A sample size of 119 students was randomly selected. The quasi-experimental design comprising pre-test, post-test, and randomized control group were employed. The Collin Rose learning styles identification and Mathematics instrument were used for data collection. Data collected were analyzed using mean, standard deviation and analysis of covariance. Results revealed that students taught Mathematics with reform-based instructional method performed better than students taught the same mathematics content with the traditional method. Also, students' achievement in mathematics was influenced by the students' leaning styles. For effective teaching and learning in Mathematics, there should be reforms in the instructional processes, taking into consideration the influence of the students' learning styles in particular.
A pilot home-based early intervention study to improve the mathematical skills of young children
Directory of Open Access Journals (Sweden)
Ayşegül Şükran Öz
2013-12-01
Full Text Available Children who come from low socioeconomic backgrounds and children with learning disabilities are found to be at risk for future failure in mathematics. Even though the mathematics scores increases over time the achievement gap remains between the various ethnic and socioeconomic groups. One way to prevent this failure is to identify the students who are at risk and provide them with effective early intervention. This study reports the results of a pilot early mathematics intervention study focusing on two Turkish families in the US. In this single-subject research, a multiple probe technique was used in order to examine the impact of the SRA DLM Math Pre-K CD-ROM in combination with parent scaffolding on young children’s number sense skills. Two parent-child dyads participated in this study. Two semi-structured interviews were conducted with the parents before and after the intervention. The child participants received 3 Mathematical Curriculum Based Measure (CBM every week to monitor their progress. Building Blocks Assessment was used to identify whether children were able to generalize the number sense skills developed during work sessions in different settings. This measure was administered both before and after the intervention.This study demonstrated that children’s and parents’ use of a software program where they work collaboratively at home resulted in increased number sense skills. These results were interpreted in the context of socio-cultural theory. The parents displayed different strategies during the mathematics work sessions, reflecting their own feelings about mathematics and technology.
PENGEMBANGAN WEB-BASED MATHEMATICS LEARNING SISWA KELAS V SDN KOTAGEDE 3 YOGYAKARTA
Directory of Open Access Journals (Sweden)
Titin Mulyaningsih
2015-07-01
Full Text Available Penelitian ini bertujuan untuk menghasilkan web-based mathematics learning yang layak untuk siswa kelas V di SD Kotagede 3 Yogyakarta. Disamping itu web-based mathematics learning yang dikembangkan dalam rangka menciptakan pembelajaran yang menyenangkan. Penelitian ini merupakan penelitian dan pengembangan yang terdiri dari 10 langkah kegiatan. Subjek penelitian ini adalah 32 siswa yang terdiri dari tiga siswa uji coba perorangan, 9 siswa uji coba kelompok kecil, dan 20 siswa uji coba lapangan. Instrumen yang digunakan dalam pengumpulan data adalah lembar validasi untuk ahli materi, ahli media dan angket tanggapan untuk siswa. Analisis data menggunakan analisis statistik deskripstif. Hasil validasi ahli materi menunjukkan skor rata-rata 80 yang termasuk kriteria sangat baik. Sedangkan hasil validasi ahli media menunjukkan skor rata-rata 70 termasuk dalam kriteria baik. Tanggapan siswa terhadap produk yang dikembangkan termasuk baik yaitu dengan perolehan skor rata-rata 17,9 atau sebesar 89,5% siswa menyatakan bahwa produk pengembangan ini layak untuk digunakan sebagai sumber belajar yang menyenangkan. Kata kunci: web-based learning, pembelajaran matematika DEVELOPING WEB-BASED MATHEMATICS LEARNING FOR THE FIFTH GRADE OF ELEMENTARY SCHOOL KOTAGEDE 3, YOGYAKARTA Abstract This study aims to produce a web-based mathematics learning viable for fifth grade students in elementary Kotagede 3 Yogyakarta. Besides, web-based learning mathematics developed in order to create a fun learning. This study is a research and development activities consist of 10 steps. The subjects were 32 students consisting of three students individual trials, nine trials a small group of students, and 20 students field trials. The instruments used in data collection is for the expert validation sheet material, media experts and questionnaire responses for the students. Analyzed using descriptive statistics. Matter expert validation results showed an average score of 80 which
Reviandari Widyatiningtyas; Yaya S. Kusumah; Utari Sumarmo; Jozua Sabandar
2015-01-01
The study was report the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students’ prior mathematical ability to student’s mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from excellent and moderate school level. The research instruments a set of mathematical critical thinking ability test, and the data were analyzed by us...
Revilla, Marta; Galán, Berta; Viguri, Javier R
2016-07-01
An integrated mathematical model is proposed for modelling a moving bed biofilm reactor (MBBR) for removal of chemical oxygen demand (COD) under aerobic conditions. The composite model combines the following: (i) a one-dimensional biofilm model, (ii) a bulk liquid model, and (iii) biological processes in the bulk liquid and biofilm considering the interactions among autotrophic, heterotrophic and predator microorganisms. Depending on the values for the soluble biodegradable COD loading rate (SCLR), the model takes into account a) the hydrolysis of slowly biodegradable compounds in the bulk liquid, and b) the growth of predator microorganisms in the bulk liquid and in the biofilm. The integration of the model and the SCLR allows a general description of the behaviour of COD removal by the MBBR under various conditions. The model is applied for two in-series MBBR wastewater plant from an integrated cellulose and viscose production and accurately describes the experimental concentrations of COD, total suspended solids (TSS), nitrogen and phosphorous obtained during 14 months working at different SCLRs and nutrient dosages. The representation of the microorganism group distribution in the biofilm and in the bulk liquid allow for verification of the presence of predator microorganisms in the second reactor under some operational conditions. PMID:27085154
Development of GaN-based micro chemical sensor nodes
Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.
2005-01-01
Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.
Using Inquiry-Based Learning to Support the Mathematical Learning of Students with SEBD
Directory of Open Access Journals (Sweden)
Jonathan Camenzuli
2014-11-01
Full Text Available This paper, which draws on action research methodology, explores the use of inquirybased learning (IBL in the teaching of mathematics to students with social, emotional and behavioural difficulties (SEBD. The year-long study was conducted in a Form 3 secondary class that grouped 13 male students with SEBD in a Maltese secondary school. After first creating an IBL-friendly classroom environment in the initial months, the actual implementation of IBL pedagogy in class began in the second term and spread over a 15 week period. The data included teacher observations that were recorded in a reflective research journal, two sessions of in-depth interviews with students, student journal writing, samples of students’ work and student marks in the school-based half yearly and annual mathematics examinations. The findings indicate that the use of IBL in the mathematics classroom can benefit students with SEBD in a number of ways. These include infusing a sense of enjoyment during lessons, improved student behaviour and motivation to learn, and facilitating the learning of mathematics which generally translated in higher achievement levels.
Polymer based on chemically modified starch
Czech Academy of Sciences Publication Activity Database
Horák, Pavel; Kruliš, Zdeněk; Šárka, E.; Kobera, Libor
Praha : Ústav makromolekulární chemie AV ČR, v. v. i, 2014. s. 82. ISBN 978-80-85009-81-1. [Česko-slovenská konference POLYMERY 2014 /8./. 06.10.2014-09.10.2014, Třešť] R&D Projects: GA TA ČR(CZ) TA04020853 Institutional support: RVO:61389013 Keywords : starch * chemical modification * degree of substitution Subject RIV: CD - Macromolecular Chemistry
Adaptive Segmentation Method for 2-D Barcode Image Base on Mathematic Morphological
Directory of Open Access Journals (Sweden)
Jianhua Li
2013-10-01
Full Text Available Segmentation is a key process of 2-D barcode identification. In this study we propose a fast adaptive segmentation method that is based on morphological method which is suitable for kinds of 2-D barcode images with different scale, angle and sort. The algorithm is based on mathematical morphology, the basic idea of the algorithm is to use Multi-scale open reconstruction of mathematical morphology to transform the image continuously, then choose whether to terminate by the results of the adjacent image transformation and finally get the final segmentation results by further processing of the images obtain from termination.The proposed approach is applied in experiments on 2-D barcodes with complicated background. The results indicated that the proposed method is very effective in adaptively 2-D barcode image segmentation.
Directory of Open Access Journals (Sweden)
Volodymyr Valentynovych Tkach
2012-07-01
Full Text Available The electroanalytic process of the detection of biosubstances, realized by the biosensor, based in conducting polyheterocyclic compounds, the function of which contained autocatalytic stage, was mathematically described. The correspondent mathematical model was analyzed by linear stability theory and bifurcational analysis. The electrochemical instabilities, capable to succeed in this process, were explained in the terms of this model.
Lin, Cheng-Yao
2008-01-01
This study explored the efficacy of web-based instruction in topics in elementary school mathematics in fostering teachers' confidence and competence in using instructional technology, and thereby promoting more positive attitudes toward using computers and Internet resources in the mathematics classroom. The results indicated that students who…
Widyatiningtyas, Reviandari; Kusumah, Yaya S.; Sumarmo, Utari; Sabandar, Jozua
2015-01-01
The study reported the findings of an only post-test control group research design and aims to analyze the influence of problem-based learning approach, school level, and students' prior mathematical ability to student's mathematics critical thinking ability. The research subjects were 140 grade ten senior high school students coming from…
DEFF Research Database (Denmark)
Palla, Mirko; Bosco, Filippo Giacomo; Yang, Jaeyoung; Rindzevicius, Tomas; Alstrøm, Tommy Sonne; Schmidt, Michael Stenbak; Lin, Qiao; Ju, Jingyue; Boisen, Anja
This paper presents the development of a novel statistical method for quantifying trace amounts of biomolecules by surface-enhanced Raman spectroscopy (SERS) using a rigorous, single molecule (SM) theory based mathematical derivation. Our quantification framework could be generalized for planar...... SERS substrates, in which the nanostructured features can be approximated as a closely spaced electromagnetic dimer problem. The potential for SM detection was also shown, which opens up an exciting opportunity in the field of SERS quantification....
How primary school teachers posed problems for inquiry based mathematics education
Czech Academy of Sciences Publication Activity Database
Hošpesová, A.; Samková, L.; Tichá, Marie; Roubíček, Filip
Prague: Charles University, Faculty of Education, 2015 - (Novotná, J.; Moraová, H.), s. 156-165 ISBN 978-80-7290-833-2. [SEMT'15 - International Symposium, Elementary Maths Teaching. Praha (CZ), 16.08.2015-21.08.2015] R&D Projects: GA ČR(CZ) GA14-01417S Institutional support: RVO:67985840 Keywords : inquiry based mathematics education * posing problems * primary school teacher training * pre-service and in-service teachers Subject RIV: AM - Education
Genevieve Lachance; Jean Ruel
2010-01-01
This paper presents an experimental study of three bioreactor configurations. The bioreactor is intended to be used for the development of tissue-engineered heart valve substitutes. Therefore it must be able to reproduce physiological flow and pressure waveforms accurately. A detailed analysis of three bioreactor arrangements is presented using mathematical models based on the windkessel (WK) approach. First, a review of the many applications of this approach in medical studies enhances its f...
Scenario Analysis of Web Service Composition based on Multi-Criteria Mathematical Goal Programming
LiYing Cui; Soundar Kumara; Dongwon Lee
2011-01-01
This paper addresses the web service composition problem considering multi-criteria regarding quality of services (QoS). Three different scenarios of multi-criteria mathematical programming models are explored under the framework of network based analysis in web service composition. This work takes care of the issues pertaining to inputs and outputs matching of web services and Quality-of-Service (QoS) at the same time. The multi-criteria programming models are explored to select the desirabl...
EXTENDING THE KNOWLEDGE BASE OF CHEMICAL ENGINEERING
Institute of Scientific and Technical Information of China (English)
Mooson Kwauk
2005-01-01
The obvious current reversion to micro-scale investigations in basic chemical engineering, combined with the need, of a quite different nature, in the rapid growth of high added-value and small-lot functional materials, have been pointing to an area not yet sufficiently covered by the unit operations, transport phenomena and chemical reaction engineering. Although it is difficult to define accurately this area, a cursory scan of the activities already in progress has revealed a few common attributes: multi-phased (structured), multi-scaled, multi-disciplined, nonlinear, needs for resolution to reductionism-solvable subsystems, and pervasive in the process industry. From these activities, the present paper drafts a tentative scheme for studying the related problems: first to dissect a problem into various scales - spatial, temporal or otherwise as best suits the case in hand- in order to identify pertinent parameters which are then organized into model formulations. Together with inter-scale model formulations, a zoom-in/zoom-out process is carried out between the scales, by trial-and-error and through reasoning, to arrive at a global formulation of a quantitative solution, in order to derive, eventually, the general from the particular.
Laursen, Sandra L.; Hassi, Marja-Liisa; Hough, Sarah
2016-02-01
This mixed-methods study describes classroom characteristics and student outcomes from university mathematics courses that are based in mathematics departments, targeted to future pre-tertiary teachers, and taught with inquiry-based learning (IBL) approaches. The study focused on three two-term sequences taught at two research universities, separately targeting elementary and secondary pre-service teachers. Classroom observation established that the courses were taught with student-centred methods that were comparable to those used in IBL courses for students in mathematics-intensive fields at the same institutions. To measure pre-service teachers' gains in mathematical knowledge for teaching, we administered the Learning Mathematics for Teaching (LMT) instrument developed by Hill, Ball and Schilling for in-service teacher professional development. Results from the LMT show that pre-service teachers made significant score gains from beginning to end of their course, while data from interviews and from surveys of learning gains show that pre-service teachers viewed their gains as relevant to their future teaching work. Measured changes on pre-/post-surveys of attitudes and beliefs were generally supportive of learning mathematics but modest in magnitude. The study is distinctive in applying the LMT to document pre-service teachers' growth in mathematical knowledge for teaching. The study also suggests IBL is an approach well suited to mathematics departments seeking to strengthen their pre-service teacher preparation offerings in ways consistent with research-based recommendations.
Applying Mathematical Optimization Methods to an ACT-R Instance-Based Learning Model.
Directory of Open Access Journals (Sweden)
Nadia Said
Full Text Available Computational models of cognition provide an interface to connect advanced mathematical tools and methods to empirically supported theories of behavior in psychology, cognitive science, and neuroscience. In this article, we consider a computational model of instance-based learning, implemented in the ACT-R cognitive architecture. We propose an approach for obtaining mathematical reformulations of such cognitive models that improve their computational tractability. For the well-established Sugar Factory dynamic decision making task, we conduct a simulation study to analyze central model parameters. We show how mathematical optimization techniques can be applied to efficiently identify optimal parameter values with respect to different optimization goals. Beyond these methodological contributions, our analysis reveals the sensitivity of this particular task with respect to initial settings and yields new insights into how average human performance deviates from potential optimal performance. We conclude by discussing possible extensions of our approach as well as future steps towards applying more powerful derivative-based optimization methods.
Chemical-Based Formulation Design: Virtual Experimentation
DEFF Research Database (Denmark)
Conte, Elisa; Gani, Rafiqul
This paper presents a software, the virtual Product-Process Design laboratory (virtual PPD-lab) and the virtual experimental scenarios for design/verification of consumer oriented liquid formulated products where the software can be used. For example, the software can be employed for the design......, the additives and/or their mixtures (formulations). Therefore, the experimental resources can focus on a few candidate product formulations to find the best product. The virtual PPD-lab allows various options for experimentations related to design and/or verification of the product. For example, the selection...... design, model adaptation). All of the above helps to perform virtual experiments by blending chemicals together and observing their predicted behaviour. The paper will highlight the application of the virtual PPD-lab in the design and/or verification of different consumer products (paint formulation...
Directory of Open Access Journals (Sweden)
Dina V. Lazareva
2015-06-01
Full Text Available A new mathematical model of asymmetric support structure frame type is built on the basis of numerical-analytical boundary elements method (BEM. To describe the design scheme used is the graph theory. Building the model taken into account is the effect of frame members restrained torsion, which presence is due to the fact that these elements are thin-walled. The built model represents a real object as a two-axle semi-trailer platform. To implement the BEM algorithm obtained are analytical expressions of the fundamental functions and vector load components. The effected calculations are based on the semi-trailer two different models, using finite elements and boundary elements methods. The analysis showed that the error between the results obtained on the basis of two numerical methods and experimental data is about 4%, that indicates the adequacy of the proposed mathematical model.
Bird, John
2014-01-01
A practical introduction to the core mathematics required for engineering study and practiceNow in its seventh edition, Engineering Mathematics is an established textbook that has helped thousands of students to succeed in their exams.John Bird's approach is based on worked examples and interactive problems. This makes it ideal for students from a wide range of academic backgrounds as the student can work through the material at their own pace. Mathematical theories are explained in a straightforward manner, being supported by practical engineering examples and applications in order to ensure
Geroch, Robert
1900-01-01
Mathematical Physics is an introduction to such basic mathematical structures as groups, vector spaces, topological spaces, measure spaces, and Hilbert space. Geroch uses category theory to emphasize both the interrelationships among different structures and the unity of mathematics. Perhaps the most valuable feature of the book is the illuminating intuitive discussion of the ""whys"" of proofs and of axioms and definitions. This book, based on Geroch's University of Chicago course, will be especially helpful to those working in theoretical physics, including such areas as relativity, particle
A FRET-based probe with a chemically deactivatable quencher.
Leriche, Geoffray; Budin, Ghyslain; Darwich, Zeinab; Weltin, Denis; Mély, Yves; Klymchenko, Andrey S; Wagner, Alain
2012-03-28
A new concept of a chemically deactivatable quencher is proposed for a FRET-based probe that turns-on its fluorescence by either an enzymatic cleavage or a chemical reagent (sodium dithionite). This concept allowed us to quantify the caspase-3 cleavage activity in solution and to reveal unreacted probes in cell experiments. PMID:22327268
A decision analytic approach to exposure-based chemical prioritization.
Directory of Open Access Journals (Sweden)
Jade Mitchell
Full Text Available The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess risks adequately are unavailable for the vast majority of chemicals in commerce. The US Environmental Protection Agency has initiated the ExpoCast Program to develop tools for rapid chemical evaluation based on potential for exposure. In this context, a model is presented in which chemicals are evaluated based on inherent chemical properties and behaviorally-based usage characteristics over the chemical's life cycle. These criteria are assessed and integrated within a decision analytic framework, facilitating rapid assessment and prioritization for future targeted testing and systems modeling. A case study outlines the prioritization process using 51 chemicals. The results show a preliminary relative ranking of chemicals based on exposure potential. The strength of this approach is the ability to integrate relevant statistical and mechanistic data with expert judgment, allowing for an initial tier assessment that can further inform targeted testing and risk management strategies.
Post secondary project-based learning in science, technology, engineering and mathematics
Rachel A Ralph
2016-01-01
Project-based learning (PjBL - to distinguish from problem-based learning - PBL) has become a recurrent practice in K-12 classroom environments. As PjBL has become prominent in K-12 classrooms, it has also surfaced in post-secondary institutions. The purpose of this paper is to examine the research that has studied a variety of science, technology, engineering and mathematic subjects using PjBL in post-secondary classrooms. Eleven articles (including qualitative, quantitative and mixed metho...
3DTS: A 3D tolerancing system based on mathematical definition
Institute of Scientific and Technical Information of China (English)
CAO Yan-long; LIU Yu-sheng; MAO Jian; YANG Jiang-xin
2006-01-01
Tolerance is almost ubiquitous during the whole product lift cycle and is imperative for seamless integration of CAD and CAM. Based on the mathematical definition of tolerance, a 3D tolerancing system, 3DTS, is presented with its design principle, system architecture and key functions. The following functional modules, tolerance modeling, semantics interpretation, 3D tolerance analysis, are described in detail. To make the tolerancing system robust and efficient, many techniques such as hierarchical tolerance representation, rule-based evaluation and non-intersection determination of tolerance zone have been devised.Tested by many samples, this system shows good robustness and practicability.
Nutti, Ylva Jannok
2013-03-01
The goal of Indigenous education is that it should be approached on the basis of the Indigenous language and culture; this is also the case with Sámi education. The Sámi School Board has stated that all teaching in Sámi schools should be culturally based, despite the fact that Sámi culture-based teaching is not specifically defined. Therefore, teachers themselves must adapt the teaching and as a result, usually no Sámi culture-based mathematics teaching takes place. The aim of this article is to discuss Indigenous teachers' experiences with designing and implementing culture-based mathematics activities in Sámi preschool and primary school. The teachers' work with culture-based mathematics activities took the form of Sámi cultural thematic work with ethnomathematical content, Multicultural school mathematics with Sámi cultural elements, and Sámi intercultural mathematics teaching. Culture-based mathematics activities took place within an action research study in the Swedish part of Sápmi. Sápmi comprises northern Norway, Sweden, and Finland, as well as the Kola Peninsula in Russia. In the action research study, six teachers conducted culture-based mathematics activities in preschool and primary school on the basis of the action research loop "plan-act-observe-reflect." During the study the teachers changed from a problem-focused perspective to a possibility-focused culture-based teaching perspective characterised by a self-empowered Indigenous teacher role, as a result of which they started to act as agents for Indigenous school change. The concept of "decolonisation" was visible in the teachers' narratives. The teachers' newly developed knowledge about the ethnomathematical research field seemed to enhance their work with Indigenous culture-based mathematics teaching.
Chemical Mixture Risk Assessment Additivity-Based Approaches
Powerpoint presentation includes additivity-based chemical mixture risk assessment methods. Basic concepts, theory and example calculations are included. Several slides discuss the use of "common adverse outcomes" in analyzing phthalate mixtures.
Rubin, Andrew
2014-01-01
This book presents concise descriptions and analysis of the classical and modern models used in mathematical biophysics. The authors ask the question "what new information can be provided by the models that cannot be obtained directly from experimental data?" Actively developing fields such as regulatory mechanisms in cells and subcellular systems and electron transport and energy transport in membranes are addressed together with more classical topics such as metabolic processes, nerve conduction and heart activity, chemical kinetics, population dynamics, and photosynthesis. The main approach is to describe biological processes using different mathematical approaches necessary to reveal characteristic features and properties of simulated systems. With the emergence of powerful mathematics software packages such as MAPLE, Mathematica, Mathcad, and MatLab, these methodologies are now accessible to a wide audience. Provides succinct but authoritative coverage of a broad array of biophysical topics and models Wr...
Thin-film chemical sensors based on electron tunneling
Khanna, S. K.; Lambe, J.; Leduc, H. G.; Thakoor, A. P.
1985-01-01
The physical mechanisms underlying a novel chemical sensor based on electron tunneling in metal-insulator-metal (MIM) tunnel junctions were studied. Chemical sensors based on electron tunneling were shown to be sensitive to a variety of substances that include iodine, mercury, bismuth, ethylenedibromide, and ethylenedichloride. A sensitivity of 13 parts per billion of iodine dissolved in hexane was demonstrated. The physical mechanisms involved in the chemical sensitivity of these devices were determined to be the chemical alteration of the surface electronic structure of the top metal electrode in the MIM structure. In addition, electroreflectance spectroscopy (ERS) was studied as a complementary surface-sensitive technique. ERS was shown to be sensitive to both iodine and mercury. Electrolyte electroreflectance and solid-state MIM electroreflectance revealed qualitatively the same chemical response. A modified thin-film structure was also studied in which a chemically active layer was introduced at the top Metal-Insulator interface of the MIM devices. Cobalt phthalocyanine was used for the chemically active layer in this study. Devices modified in this way were shown to be sensitive to iodine and nitrogen dioxide. The chemical sensitivity of the modified structure was due to conductance changes in the active layer.
Piezoresistive Chemical Sensors Based on Functionalized Hydrogels
Directory of Open Access Journals (Sweden)
Margarita Guenther
2014-06-01
Full Text Available Thin films of analyte-specific hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain chemomechanical sensors that can serve as selective biochemical sensors for a continuous monitoring of metabolites. The gel swelling pressure has been monitored in simulated physiological solutions by means of the output signal of piezoresistive sensors. The interference by fructose, human serum albumin, pH, and ionic concentration on glucose sensing was studied. With the help of a database containing the calibration curves of the hydrogel-based sensors at different values of pH and ionic strength, the corrected values of pH and glucose concentration were determined using a novel calibration algorithm.
Directory of Open Access Journals (Sweden)
Hongli Liu
2012-11-01
Full Text Available Adopting the microscopic observation imaging and digital image processing technologies, this paper researches a new measuring method of indoor inhalable particulate matter concentration and size distribution .It realizes denoising, binarization, filtering and edge detection to based on mathematical morphology, regional filled and calibration detection to particulate matter image, designs the parameters recognition algorithm for particulate matter size, fractal dimension ,shape factors and so on, then calculates the concentration and size distribution of particulate matter using data fusion method. The experimental results show that the method has advantages with intuitive, high precision, fast processing speed ,easily data statistics, clearly data analysis and stable measuring results.
New Mathematical Model Based on Affine Transformation for Remote Sensing Image with High Resolution
Institute of Scientific and Technical Information of China (English)
无
2003-01-01
This paper calculates the parameters of image position and orientation,proposes a mathematical model and adopts a new method with three steps of transformations based on parallel ray projection.Every step of the model is strict,and the map function of each transformation is the first order polynomials and other simple function.The final calculation of the parameters is for the linear equations with good status.As a result,the problem of the relativity of image parameter calculation is solved completely.Some experiments are carried out.
Firefly Optimization and Mathematical Modeling of a Vehicle Crash Test Based on Single-Mass
Andreas Klausen; Sondre Sanden Tørdal; Hamid Reza Karimi; Robbersmyr, Kjell G.; Mladen Jecmenica; Ole Melteig
2014-01-01
In this paper mathematical modeling of a vehicle crash test based on a single-mass is studied. The model under consideration consists of a single-mass coupled with a spring and/or a damper. The parameters for the spring and damper are obtained by analyzing the measured acceleration in the center of gravity of the vehicle during a crash. A model with a nonlinear spring and damper is also proposed and the parameters will be optimized with different damper and spring characteristics and optimiza...
Perspectives of IT Artefacts: Information Systems based on Complex Mathematical Models
DEFF Research Database (Denmark)
Carugati, Andrea
2002-01-01
A solution for production scheduling that is lately attracting the interests of the manufacturing industry involves the use of complex mathematical modeling techniques in scheduling software. However this technology is fairly unknown among manufacturing practitioners, as are the social problems o...... its development and use. The aim of this article is to show how an approach based on multiple perspectives can help understand the emergence of complex software and help understand why and how the reasons and motives of the different stakeholders are, at times, incompatible....
Mathematical model of turnout electric drive work based on a linear motor.
МАСЛИЙ, Ар С; МАСЛИЙ, Ан С; БУРЯКОВСКИЙ, С. Г.; Любарский, Б. Г.
2015-01-01
The article considers mathematical model of electric drive work based on a linear motor. Linear motors are electric induction motors that produce motion in a straight line rather than rotational motion. They are now used in all sorts of machines that require linear (as opposed to rotational) motion, including overhead traveling cranes and beltless conveyors for moving sheet metal. They are probably best known as the source of motive power in the latest generation of high-speed magnetic levita...
Phylogenetic Analysis of H7N9 Avian Influenza Virus Based on a Novel Mathematical Descriptor
Yusheng Bai; Tingting Ma; Yuhua Yao; Qi Dai; Ping-an He
2014-01-01
A new mathematical descriptor was proposed based on 3D graphical representation. Using the method, we construct the phylogenetic trees of nine proteins of H7N9 influenza virus to analyze the originated source of H7N9. The results show that the evolution route of H7N9 avian influenza is from America through Europe to Asia. Furthermore, two samples collected from environment in Nanjing and Zhejiang and one sample collected from chicken are the sources of H7N9 influenza virus that infected human...
Plasmonics Based Harsh Environment Compatible Chemical Sensors
Energy Technology Data Exchange (ETDEWEB)
Michael Carpenter
2012-01-15
Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500Â°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined
Nondestructive inspection of chemical warfare based on API-TOF
International Nuclear Information System (INIS)
Background: Real-time, fast, accurate, nondestructive inspection (NDI) and quantitative analysis for chemical warfare are very imperative for chemical defense, anti-terror and nation security. Purpose: Associated Particles Technique (APT)/Neutron Time of Flight (TOF) has been developed for non-invasive inspection of sealed containers with chemical warfare agents. Methods: A prototype equipment for chemical warfare is consisted of an APT neutron generator with a 3×3 matrix of semiconductor detectors of associated alpha-particles, the shielding protection of neutron and gamma-ray, arrayed NaI(Tl)-based detectors of gamma-rays, fully-digital data acquisition electronics, data analysis, decision-making software, support platform and remote control system. Inelastic scattering gamma-ray pulse height spectra of sarin, VX, mustard gas and adamsite induced by 14-MeV neutron are measured. The energies of these gamma rays are used to identify the inelastic scattering elements, and the intensities of the peaks at these energies are used to reveal their concentrations. Results: The characteristic peaks of inelastic scattering gamma-ray pulse height spectra show that the prototype equipment can fast and accurately inspect chemical warfare. Conclusion: The equipment can be used to detect not only chemical warfare agents but also other hazardous materials, such as chemical/toxic/drug materials, if their chemical composition is in any way different from that of the surrounding materials. (authors)
Utilization of chemical abstracts service (CAS) data bases
International Nuclear Information System (INIS)
A method is developed describing the economic utilization of the Chemical Abstracts Service data bases CA Condensates and Chemical Abstracts Subject Index Alertin order to supplement the data base of the IDC-Inorganica-Documentationsystem built up to meet the peculiarities of the inorganic chemistry. The method consists of EDP-Programs and processes at which special authority files for coded compound and subject entries play an important role. One of the advantages of the method is that the intellectual effort necessary to create such a data base is reduced to a minimum. The authority files may be also used for orther purposes. (orig.) 891 WB 892 MB
A novel mathematical technique to assess of the mitral valve dynamics based on echocardiography
Karvandi, Mersedeh; Hassantash, Seyed Ahmad; Foroughi, Mahnoosh
2015-01-01
Purpose: The mechanics of the mitral valve leaflet as a nonlinear, inelastic and anisotropic soft tissue results from an integrated response of many mathematical/physical indexes' that illustrate the tissue. In the past decade, finite element modeling of complete heart valves has greatly aided evaluation of heart valve surgery, design of bioprosthetic valve replacements, and general understanding of healthy and abnormal cardiac function. Such a model must be based on an accurate description of the mechanical behavior of the valve material. It is essential to calculate velocity/displacement and strain rate/strain at a component level that is to work at the cellular level. In this study we developed the first three-dimensional displacement vectors field in the characterization of mitral valve leaflets in continuum equations of inelasticity framework based on echocardiography. Method: Much of our knowledge of abnormal mitral valve function is based on surgical and post-mortem studies while these studies are quan...
Chemical Functionalization Effects on Cubane-Based Chain Electronic Transport
Konstantin P. Katin; Mikhail M. Maslov
2015-01-01
We report electronic structure calculations in chemically functionalized linear cubane-based chains. The effects of covalent chemical attachments on chain transport properties are examined with nonorthogonal tight-binding model (NTBM) considering Landauer-Büttiker formalism. The covalent bonding of even a single-type functional group is shown to considerably alter the conductance of the chain. For similar radical doping density, electronic characteristics are found to range from insulator to ...
Graphene Electronic Device Based Biosensors and Chemical Sensors
Jiang, Shan
2014-01-01
Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first...
Evaluation of thorium based nuclear fuel. Chemical aspects
International Nuclear Information System (INIS)
This report describes the chemical aspects of a thorium-based fuel cycle. It is part of a series devoted to the study of thorium-based fuel as a means to achieve a considerable reduction of the radiotoxicity of the waste from nuclear power production. Therefore special emphasis is placed on fuel (re-)fabrication and fuel reprocessing in the present work. (orig.)
M. N. Modebelu; C. C. Ogbonna
2014-01-01
This study aimed at determining the effect of reform-based-instructional method learning styles on students’ achievement and retention in mathematics. A sample size of 119 students was randomly selected. The quasi-experimental design comprising pre-test, post-test, and randomized control group were employed. The Collin Rose learning styles identification and Mathematics instrument were used for data collection. Data collected were analyzed using mean, standard deviation and analysis of covari...
International Nuclear Information System (INIS)
Mathematical methods are being increasingly employed in the efficiency calibration of gamma based systems for non-destructive assay (NDA) of radioactive waste and for the estimation of the Total Measurement Uncertainty (TMU). Recently, ASTM (American Society for Testing and Materials) released a standard guide for use of modeling passive gamma measurements. This is a testimony to the common use and increasing acceptance of mathematical techniques in the calibration and characterization of NDA systems. Mathematical methods offer flexibility and cost savings in terms of rapidly incorporating calibrations for multiple container types, geometries, and matrix types in a new waste assay system or a system that may already be operational. Mathematical methods are also useful in modeling heterogeneous matrices and non-uniform activity distributions. In compliance with good practice, if a computational method is used in waste assay (or in any other radiological application), it must be validated or benchmarked using representative measurements. In this paper, applications involving mathematical methods in gamma based NDA systems are discussed with several examples. The application examples are from NDA systems that were recently calibrated and performance tested. Measurement based verification results are presented. Mathematical methods play an important role in the efficiency calibration of gamma based NDA systems. This is especially true when the measurement program involves a wide variety of complex item geometries and matrix combinations for which the development of physical standards may be impractical. Mathematical methods offer a cost effective means to perform TMU campaigns. Good practice demands that all mathematical estimates be benchmarked and validated using representative sets of measurements. (authors)
Institute of Scientific and Technical Information of China (English)
LIN Hui; DU Pei-jun; ZHAO Chang-sheng; SHU Ning
2004-01-01
This paper puts forward an effective,specific algorithm for edge detection.Based on multi-structure elements of gray mathematics morphology,in the light of difference between noise and edge shape of RS images,the paper establishes multi-structure elements to detect edge by utilizing the grey form transformation principle.Compared with some classical edge detection operators,such as Sobel Edge Detection Operator,LOG Edge Detection Operator,and Canny Edge Detection Operator,the experiment indicates that this new algorithm possesses very good edge detection ability,which can detect edges more effectively,but its noise-resisting ability is relatively low.Because of the bigger noise of remote sensing image,the authors probe into putting forward other edge detection method based on combination of wavelet directivity checkout technology and small-scale Mathematical Morphology finally.So,position at the edge can be accurately located,the noise can be inhibited to a certain extent and the effect of edge detection is obvious.
Najman, Laurent
2013-01-01
Mathematical Morphology allows for the analysis and processing of geometrical structures using techniques based on the fields of set theory, lattice theory, topology, and random functions. It is the basis of morphological image processing, and finds applications in fields including digital image processing (DSP), as well as areas for graphs, surface meshes, solids, and other spatial structures. This book presents an up-to-date treatment of mathematical morphology, based on the three pillars that made it an important field of theoretical work and practical application: a solid theoretical foun
Computing multi-species chemical equilibrium with an algorithm based on the reaction extents
DEFF Research Database (Denmark)
Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.;
2013-01-01
A mathematical model for the solution of a set of chemical equilibrium equations in a multi-species and multiphase chemical system is described. The computer-aid solution of model is achieved by means of a Newton-Raphson method enhanced with a line-search scheme, which deals with the non-negative...
Review of Evidence-Based Mathematics Interventions for Students with Autism Spectrum Disorders
Hart Barnett, Juliet E.; Cleary, Shannon
2015-01-01
Students with autism spectrum disorders (ASD) are being included more frequently in the general educational setting, and are therefore increasingly expected to access and master core curricular content, including mathematics. However, mathematics often presents challenges to students with ASD. Interventions to improve the mathematics skills of…
Teaching Secondary School Mathematics and Statistics: Evidence-Based Practice. Volume 2
Averill, Robin; Harvey, Roger
2009-01-01
"We can never be sure that there is not some wild, untamed piece of mathematics ready to spring out on us... This is what keeps mathematics enchanting." This is how Jim Neyland, one of the contributing authors to this book, describes mathematics. His enthusiasm and energy are echoed throughout by many of the other writers. This is a book to…
Teaching Secondary School Mathematics and Statistics: Evidence-Based Practice. Volume 1
Averill, Robin; Harvey, Roger
2009-01-01
"Mathematics is more than skills... it is also the excitement of discovery." This is how Derek Holton, one of the contributing authors to this book, defines mathematics. His enthusiasm and energy are echoed throughout by many of the other writers. This is a book to delight mathematics teachers at all stages: experienced and inexperienced;…
Mathematical Modeling of Biosensors Based on an Array of Enzyme Microreactors
Baronas, Romas; Ivanauskas, Feliksas; Kulys, Juozas
2006-01-01
This paper presents a two-dimensional-in-space mathematical model of biosensors based on an array of enzyme microreactors immobilised on a single electrode. The modeling system acts under amperometric conditions. The microreactors were modeled by particles and by strips. The model is based on the diffusion equations containing a non-linear term related to the Michaelis-Menten kinetics of the enzymatic reaction. The model involves three regions: an array of enzyme microreactors where enzyme reaction as well as mass transport by diffusion takes place, a diffusion limiting region where only the diffusion takes place, and a convective region, where the analyte concentration is maintained constant. Using computer simulation, the influence of the geometry of the microreactors and of the diffusion region on the biosensor response was investigated. The digital simulation was carried out using the finite difference technique.
Mathematical Modeling of Biosensors Based on an Array of Enzyme Microreactors
Directory of Open Access Journals (Sweden)
Juozas Kulys
2006-04-01
Full Text Available This paper presents a two-dimensional-in-space mathematical model ofbiosensors based on an array of enzyme microreactors immobilised on a single electrode.The modeling system acts under amperometric conditions. The microreactors were modeledby particles and by strips. The model is based on the diffusion equations containing a non-linear term related to the Michaelis-Menten kinetics of the enzymatic reaction. The modelinvolves three regions: an array of enzyme microreactors where enzyme reaction as well asmass transport by diffusion takes place, a diffusion limiting region where only the diffusiontakes place, and a convective region, where the analyte concentration is maintained constant.Using computer simulation, the influence of the geometry of the microreactors and of thediffusion region on the biosensor response was investigated. The digital simulation wascarried out using the finite difference technique.
Charafi, My. M.; Sadok, A.; Kamal, A.; Menai, A.
A quasi-three-dimensional mathematical model has been developed to study the morphological processes based on equilibrium sediment transport method. The flow velocities are computed by a two-dimensional horizontal depth-averaged flow model (H2D) in combination with logarithmic velocity profiles. The transport of sediment particles by a flow water has been considered in the form of bed load and suspended load. The bed load transport rate is defined as the transport of particles by rolling and saltating along the bed surface and is given by the Van Rijn relationship (1987). The equilibrium suspended load transport is described in terms of an equilibrium sediment concentration profile (ce) and a logarithmic velocity (u). Based on the equilibrium transport, the bed change rate is given by integration of the sediment mass-balance equation. The model results have been compared with a Van Rijn results (equilibrium approach) and good agreement has been found.
International Nuclear Information System (INIS)
High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nano composites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied, and the temperature difference along the thickness direction of wood was very significant; The temperature with wood firstly increased and then gradually decreased from the wood surface to interior when the bilateral microwave heating was applied. Compared with the unilateral microwave heating, bilateral microwave heating is a better microwave heating method for the more uniform wood microwave pretreatment.
DEFF Research Database (Denmark)
Carugati, Andrea
2002-01-01
systems development. In a presented case the indications of the model are compared with the decisions taken during the development. The results highlight discrepancies between the structure and predictions of the model and the case observations, especially with regard to the importance given to the users......’ skills in the development process. Further observations also indicate that flexibility and adaptability, based on grounded theory, are valuable tools when information systems development involves a new technology....... has been initiated with the scope of investigating the questions that mathematical modelling technology poses to traditional information systems development projects. Based on the past body of research, this study proposes a framework to guide decision making for managing projects of information...
Structural and Chemical Diversity of Tl-Based Cuprate Superconductors
Institute of Scientific and Technical Information of China (English)
信赢
2003-01-01
The Tl-based cuprate superconductor family is the largest family in crystal structure and chemical composition among all high Tc cuprate superconductors. The Tl family can be divided into two sub-families, the Tl single layer family and the Tl double layer family, based on their crystal structural characteristics. The Tl single layer family is an ideal material for investigating the evolution of crystalline formation, charge carrier density, chemical composition, transport properties, superconductivity and their relationships. The Tl family contains almostall possible crystal structures discovered in high-Tc cuprate superconductors. Tl cuprate superconductors are of great importance not only in studying high-temperature superconductivity but also in commercial applications.
Chemical Functionalization Effects on Cubane-Based Chain Electronic Transport
Directory of Open Access Journals (Sweden)
Konstantin P. Katin
2015-01-01
Full Text Available We report electronic structure calculations in chemically functionalized linear cubane-based chains. The effects of covalent chemical attachments on chain transport properties are examined with nonorthogonal tight-binding model (NTBM considering Landauer-Büttiker formalism. The covalent bonding of even a single-type functional group is shown to considerably alter the conductance of the chain. For similar radical doping density, electronic characteristics are found to range from insulator to narrow-gap semiconductor depending on the nature of the covalent bonding. Therefore it has become possible to tune electronic properties of the cubane-based one-dimensional oligomers by the functionalization for nanoelectronic applications.
Directory of Open Access Journals (Sweden)
Sayantan Nath
2015-09-01
Full Text Available In this paper, integration between multiple functions of image processing and its statistical parameters for intelligent alarming series based fire detection system is presented. The proper inter-connectivity mapping between processing elements of imagery based on classification factor for temperature monitoring and multilevel intelligent alarm sequence is introduced by abstractive canonical approach. The flow of image processing components between core implementation of intelligent alarming system with temperature wise area segmentation as well as boundary detection technique is not yet fully explored in the present era of thermal imaging. In the light of analytical perspective of convolutive functionalism in thermal imaging, the abstract algebra based inter-mapping model between event-calculus supported DAGSVM classification for step-by-step generation of alarm series with gradual monitoring technique and segmentation of regions with its affected boundaries in thermographic image of coal with respect to temperature distinctions is discussed. The connectedness of the multifunctional operations of image processing based compatible fire protection system with proper monitoring sequence is presently investigated here. The mathematical models representing the relation between the temperature affected areas and its boundary in the obtained thermal image defined in partial derivative fashion is the core contribution of this study. The thermal image of coal sample is obtained in real-life scenario by self-assembled thermographic camera in this study. The amalgamation between area segmentation, boundary detection and alarm series are described in abstract algebra. The principal objective of this paper is to understand the dependency pattern and the principles of working of image processing components and structure an inter-connected modelling technique also for those components with the help of mathematical foundation.
Lee, Chang Jun
2015-01-01
In the fields of researches associated with plant layout optimization, the main goal is to minimize the costs of pipelines and pumping between connecting equipment under various constraints. However, what is the lacking of considerations in previous researches is to transform various heuristics or safety regulations into mathematical equations. For example, proper safety distances between equipments have to be complied for preventing dangerous accidents on a complex plant. Moreover, most researches have handled single-floor plant. However, many multi-floor plants have been constructed for the last decade. Therefore, the proper algorithm handling various regulations and multi-floor plant should be developed. In this study, the Mixed Integer Non-Linear Programming (MINLP) problem including safety distances, maintenance spaces, etc. is suggested based on mathematical equations. The objective function is a summation of pipeline and pumping costs. Also, various safety and maintenance issues are transformed into inequality or equality constraints. However, it is really hard to solve this problem due to complex nonlinear constraints. Thus, it is impossible to use conventional MINLP solvers using derivatives of equations. In this study, the Particle Swarm Optimization (PSO) technique is employed. The ethylene oxide plant is illustrated to verify the efficacy of this study. PMID:26027708
Optimization of Cooling Process of Iron Ore Pellets Based on Mathematical Model and Data Mining
Institute of Scientific and Technical Information of China (English)
Gui-ming YANG; Xiao-hui FAN; Xu-ling CHEN; Xiao-xian HUANG; Xi LI
2015-01-01
Cooling process of iron ore pellets in a circular cooler has great impacts on the pellet quality and systematic energy exploitation. However, multi-variables and non-visualization of this gray system is unfavorable to efifcient production. Thus, the cooling process of iron ore pellets was optimized using mathematical model and data mining techniques. A mathematical model was established and validated by steady-state production data, and the results show that the calculated values coincide very well with the measured values. Based on the proposed model, effects of important process parameters on gas-pellet temperature proifles within the circular cooler were analyzed to better understand the entire cooling process. Two data mining techniques—Associa-tion Rules Induction and Clustering were also applied on the steady-state production data to obtain expertise operating rules and optimized targets. Finally, an optimized control strategy for the circular cooler was proposed and an operation guidance system was developed. The system could realize the visualization of thermal process at steady state and provide operation guidance to optimize the circular cooler.
Improving Mathematical Optimization Techniques with the Aid of Exergy-Based Variables
Directory of Open Access Journals (Sweden)
George Tsatsaronis
2009-06-01
Full Text Available
The design optimization of energy conversion plants requires sophisticated optimization techniques. The usefulness of mathematical programming approaches has been discussed in several papers. Usually, the quality of the computed solutions, concerning global optimality and the convergence speed, is not discussed in these papers and even the existence of local optimal solutions is not mentioned. Indeed, the optimization of nonconvex mixed integer non-linear problems (MINLP, such as the structural and design optimization of power plants, is a very difficult problem. However, knowledge of the real optimization potential can assist the design engineer in better understanding the optimization procedure. This article deals with the use of exergetic variables for improving the quality of results obtained from mathematical optimization techniques and their convergence speed. LaGO, the solver used to compute the discussed results, can evaluate the obtained solution of the discussed minimization problems by calculating lower bounds of the original problem based on a relaxed convex objective function. Here, the use of exergetic variables can help to increase the lower bounds significantly and thus, to improve the evaluation of the computed solutions and the convergence speed. The method is applied to different optimization tasks.
Satellite-rocket docking ring recognition method based on mathematical morphology
Xu, Zhiqiang; Shang, Yang; Ma, Xuan
2015-10-01
Satellite-rocket docking ring recognition method based on mathematical morphology is presented in this paper, according to the geometric and grayscale characteristics of the docking ring typical structure. The docking ring used in this paper is a circle with a cross in the middle. Most of spacecrafts are transported into orbit by rocket, and they retain the connection component with the rocket. The tracing spacecraft should capture the target spacecraft first before operating the target spacecraft. The docking ring is one of the typical parts of a spacecraft, and it can be recognized automatically. Thereby we can capture the spacecraft through the information of the docking ring. Firstly a multi-step mathematical morphology processing is applied to the image of the target spacecraft with different structure element, followed by edge detection and line detection, and finally docking ring typical structure is located in the image by relative geometry analysis. The images used in this paper are taken of real satellite in lab. The docking ring can be recognized when the distance between the two spacecraft is different. The results of physical simulation experiment show that the method in this paper can recognize docking ring typical structure accurately when the tracing spacecraft is approaching the target spacecraft.
Modelers' perception of mathematical modeling in epidemiology: a web-based survey.
Directory of Open Access Journals (Sweden)
Gilles Hejblum
Full Text Available BACKGROUND: Mathematical modeling in epidemiology (MME is being used increasingly. However, there are many uncertainties in terms of definitions, uses and quality features of MME. METHODOLOGY/PRINCIPAL FINDINGS: To delineate the current status of these models, a 10-item questionnaire on MME was devised. Proposed via an anonymous internet-based survey, the questionnaire was completed by 189 scientists who had published in the domain of MME. A small minority (18% of respondents claimed to have in mind a concise definition of MME. Some techniques were identified by the researchers as characterizing MME (e.g. Markov models, while others-at the same level of sophistication in terms of mathematics-were not (e.g. Cox regression. The researchers' opinions were also contrasted about the potential applications of MME, perceived as highly relevant for providing insight into complex mechanisms and less relevant for identifying causal factors. The quality criteria were those of good science and were not related to the size and the nature of the public health problems addressed. CONCLUSIONS/SIGNIFICANCE: This study shows that perceptions on the nature, uses and quality criteria of MME are contrasted, even among the very community of published authors in this domain. Nevertheless, MME is an emerging discipline in epidemiology and this study underlines that it is associated with specific areas of application and methods. The development of this discipline is likely to deserve a framework providing recommendations and guidance at various steps of the studies, from design to report.
DEFF Research Database (Denmark)
Westphael, Henning; Mogensen, Arne
2013-01-01
In this article we present the notion of Mathematical competences as a tool to describe the mathematically gifted students.......In this article we present the notion of Mathematical competences as a tool to describe the mathematically gifted students....
Applied mathematics for science and engineering
Glasgow, Larry A
2014-01-01
Prepare students for success in using applied mathematics for engineering practice and post-graduate studies moves from one mathematical method to the next sustaining reader interest and easing the application of the techniques Uses different examples from chemical, civil, mechanical and various other engineering fields Based on a decade's worth of the authors lecture notes detailing the topic of applied mathematics for scientists and engineers Concisely writing with numerous examples provided including historical perspectives as well as a solutions manual for academic adopters
Chemical Information in Scirus and BASE (Bielefeld Academic Search Engine)
Bendig, Regina B.
2009-01-01
The author sought to determine to what extent the two search engines, Scirus and BASE (Bielefeld Academic Search Engines), would be useful to first-year university students as the first point of searching for chemical information. Five topics were searched and the first ten records of each search result were evaluated with regard to the type of…
Durable chemical sensors based on field-effect transistors
Reinhoudt, D.N.
1995-01-01
The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se
Kurtulus, Aytac
2013-01-01
The aim of this study was to investigate the effects of web-based interactive virtual tours on the development of prospective mathematics teachers' spatial skills. The study was designed based on experimental method. The "one-group pre-test post-test design" of this method was taken as the research model. The study was conducted with 3rd year…
Mathematical problems for chemistry students
Pota, Gyorgy
2006-01-01
Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistry students in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialists of the chemistry-related fields (physicists, mathematicians, biologists, etc.) into the world of the chemical applications. Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, other
Mathematical problems for chemistry students
Pota, Gyorgy
2011-01-01
Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we
Harper, Marc
2013-01-01
We show that individual topics and skills can have a dramatic effect on the outcomes of students in various mathematics courses at the University of Illinois. Data from the placement program at Illinois associates a knowledge state, a subset of 182 items and skills that a student is able to complete successfully and repeatedly, with their final grades in a variety of courses from college algebra through multivariate calculus. Using various conditional probabilities and odds ratios, we classify items based on their association with successful and unsuccessful course outcomes, showing that some skills that are advanced for some courses are fundamental or basic to more advanced courses. We examine the impact of specific items across the courses in the traditional college algebra, precalculus, and calculus sequence, as well as courses not typically covered by placement programs, such as higher calculus courses. Visualizations of the knowledge states associated to each student are given for some specific courses a...
Research on Routing Algorithm Based on Limitation Arrangement Principle in Mathematics
Directory of Open Access Journals (Sweden)
Jianhui Lv
2014-01-01
Full Text Available Since the research on information consistency of the whole network under OSPF protocol has been insufficient in recent years, an algorithm based on limitation arrangement principle for routing decision is proposed and it is a permutation and combination problem in mathematical area. The most fundamental function of this algorithm is to accomplish the information consistency of the whole network at a relatively fast speed. Firstly, limitation arrangement principle algorithm is proposed and proved. Secondly, LAP routing algorithm in single link network and LAP routing algorithm in single link network with multiloops are designed. Finally, simulation experiments are worked by VC6.0 and NS2, which proves that LAPSN algorithm and LAPSNM algorithm can solve the problem of information consistency of the whole network under OSPF protocol and LAPSNM algorithm is superior to Dijkstra algorithm.
Characterization of Chemical and Mechanical Properties of Polymer Based Nanocomposites
Wafy, Tamer
2013-01-01
Characterization of Chemical and Mechanical Properties of Polymer Based NanocompositesThe University of ManchesterTamer Wafy Doctor of Philosophy17 January, 2013One of the most significant issues in nanocomposite performance is improving the dispersion of carbon nanotubes (CNTs) in thermosetting or thermoplastic polymers in order to gain good mechanical properties. Several studies have investigated the fabrication of nanocomposites based on carbon nanotubes and analysed properties, but there ...
The Formalization of Syntax-Based Mathematical Algorithms Using Quotation and Evaluation
Farmer, William M.
2013-01-01
Algorithms like those for differentiating functional expressions manipulate the syntactic structure of mathematical expressions in a mathematically meaningful way. A formalization of such an algorithm should include a specification of its computational behavior, a specification of its mathematical meaning, and a mechanism for applying the algorithm to actual expressions. Achieving these goals requires the ability to integrate reasoning about the syntax of the expressions with reasoning about ...
A pilot home-based early intervention study to improve the mathematical skills of young children
Ayşegül Şükran Öz
2013-01-01
Children who come from low socioeconomic backgrounds and children with learning disabilities are found to be at risk for future failure in mathematics. Even though the mathematics scores increases over time the achievement gap remains between the various ethnic and socioeconomic groups. One way to prevent this failure is to identify the students who are at risk and provide them with effective early intervention. This study reports the results of a pilot early mathematics intervention study fo...
Liber Mathematicae: A Web-Based Documentation and Collaboration Project for Mathematics
Pflaum, Markus J
2011-01-01
Traditionally, mathematical knowledge is published in printed media such as books or journals. With the advent of the Internet, a new method of publication became available. To date, however, most online mathematical publications do not employ the full capabilities of the medium. We describe a project to modernize online mathematics presentation and build a community-focused environment in which the lines between "author" and "reader" are blurred, enhancing collaboration and improving publication quality.
Liber Mathematicae: A Web-Based Documentation and Collaboration Project for Mathematics
Pflaum, Markus J.; Tuley, John
2011-01-01
Traditionally, mathematical knowledge is published in printed media such as books or journals. With the advent of the Internet, a new method of publication became available. To date, however, most online mathematical publications do not employ the full capabilities of the medium. We describe a project to modernize online mathematics presentation and build a community-focused environment in which the lines between "author" and "reader" are blurred, enhancing collaboration and improving publica...
Mathematical Thinking in Chemistry
José L. Villaveces; Guillermo Restrepo
2012-01-01
Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffro...
Energy Technology Data Exchange (ETDEWEB)
Salloum, Maher N.; Gharagozloo, Patricia E.
2013-10-01
Metal particle beds have recently become a major technique for hydrogen storage. In order to extract hydrogen from such beds, it is crucial to understand the decomposition kinetics of the metal hydride. We are interested in obtaining a a better understanding of the uranium hydride (UH3) decomposition kinetics. We first developed an empirical model by fitting data compiled from different experimental studies in the literature and quantified the uncertainty resulting from the scattered data. We found that the decomposition time range predicted by the obtained kinetics was in a good agreement with published experimental results. Secondly, we developed a physics based mathematical model to simulate the rate of hydrogen diffusion in a hydride particle during the decomposition. We used this model to simulate the decomposition of the particles for temperatures ranging from 300K to 1000K while propagating parametric uncertainty and evaluated the kinetics from the results. We compared the kinetics parameters derived from the empirical and physics based models and found that the uncertainty in the kinetics predicted by the physics based model covers the scattered experimental data. Finally, we used the physics-based kinetics parameters to simulate the effects of boundary resistances and powder morphological changes during decomposition in a continuum level model. We found that the species change within the bed occurring during the decomposition accelerates the hydrogen flow by increasing the bed permeability, while the pressure buildup and the thermal barrier forming at the wall significantly impede the hydrogen extraction.
Directory of Open Access Journals (Sweden)
Özcan Dülger
2014-05-01
Full Text Available Predicting Mathematics 1 course success of students is very important to prepare them before the semester. It is difficult to obtain solution because of the non-linear property of data set. Fuzzy logic is one of the common methods for the problems which involve numeric values. In fuzzy logic, it is important to determine membership functions and their parameter's values correctly. This can be done by an expert or can be learned with a data set. In this study, we aimed to predict the Mathematics 1 course success of 434 students who enrolled to Engineering Faculty of Pamukkale University in 2007-2008 academic year by using their university exam data. For this, the adaptive-network-based fuzzy inference system (ANFIS which combines the important characteristics of artificial neural network and fuzzy logic was used. In training section, nine parameters which are selected from sixteen parameters in data set with different combinations were given to the ANFIS. When an ANFIS structure with nine input parameters has at least three membership functions for each input, it will have at least 3^9 fuzzy rules. Because of this, the training part is too slow and too much memory is needed. Instead of this inefficient structure, a hierarchical method was proposed. In this method, the ANFIS is partitioned to the sub-systems. Each sub-system performs some part of input parameters and sends their result to the final ANFIS structure to obtain the overall system output. After testing with one-third of data set, two best prediction results with ratio 77.77% and 78.47% are obtained. When these results are analyzed, it is seen that 64 successful students from 85 students and 48 unsuccessful students from 59 students in Mathematics 1 course were predicted truly in the result with ratio 77.77%. Similarly, 69 successful students from 85 students, and 44 unsuccessful students from 59 students were predicted truly in the result with ratio 78.47%.
[Medicinal values and their chemical bases of Paris].
Wang, Yue-hu; Niu, Hong-mei; Zhang, Zhao-yun; Hu, Xiang-yang; Li, Heng
2015-03-01
Medicinal values and their chemical bases of Paris (Trilliaceae) are reviewed. Paris plants include 40 species and varieties. Among them, 18 ones are medicinal plants with similarity in traditional uses. Fourteen species have been studied phytochemically, which led to isolation of 207 compounds including 121 steroidal saponins. These saponins are major active constituents from Paris plants, which can explain the traditional uses of the plants to treat cancer, malignant boil, bleeding, gastritis, and so on. The similarity in medicinal uses and chemical constituents of Paris plants implies the possibility of resource substitution among these species. It is worth to further investigate Paris plants in chemical constituents, pharmacological activity, biological property, and toxicology. PMID:26087542
Chemical interaction matrix between reagents in a Purex based process
International Nuclear Information System (INIS)
The United States Department of Energy (DOE) is the responsible entity for the disposal of the United States excess weapons grade plutonium. DOE selected a PUREX-based process to convert plutonium to low-enriched mixed oxide fuel for use in commercial nuclear power plants. To initiate this process in the United States, a Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF) is under construction and will be operated by Shaw AREVA MOX Services at the Savannah River Site. This facility will be licensed and regulated by the U.S. Nuclear Regulatory Commission (NRC). A PUREX process, similar to the one used at La Hague, France, will purify plutonium feedstock through solvent extraction. MFFF employs two major process operations to manufacture MOX fuel assemblies: (1) the Aqueous Polishing (AP) process to remove gallium and other impurities from plutonium feedstock and (2) the MOX fuel fabrication process (MP), which processes the oxides into pellets and manufactures the MOX fuel assemblies. The AP process consists of three major steps, dissolution, purification, and conversion, and is the center of the primary chemical processing. A study of process hazards controls has been initiated that will provide knowledge and protection against the chemical risks associated from mixing of reagents over the life time of the process. This paper presents a comprehensive chemical interaction matrix evaluation for the reagents used in the PUREX-based process. Chemical interaction matrix supplements the process conditions by providing a checklist of any potential inadvertent chemical reactions that may take place. It also identifies the chemical compatibility/incompatibility of the reagents if mixed by failure of operations or equipment within the process itself or mixed inadvertently by a technician in the laboratories. (authors)
Mathematical Modeling of Plant Allelopathic Hormesis Based on Ecological-Limiting-Factor Models
Liu, Yinghu; Chen, Xiaoqiu; Duan, Shunshan; Feng, Yuanjiao; An, Min
2010-01-01
Allelopathy arises from the release of chemicals by one plant species that affect other species in its vicinity, usually to their detriment. Allelopathic effects have been demonstrated to be limiting factors for species distributions and ecological processes in some natural or agricultural communities. Based on the biphasic hormetic responses of plants to allelochemicals, ecological-limiting-factor models were introduced into the An-Johnson-Lovett hormesis model to improve modelling the pheno...
A Systematic Methodology for Design of Emulsion Based Chemical Products
DEFF Research Database (Denmark)
Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul
2012-01-01
A systematic methodology for emulsion based chemical product design is presented. The methodology employs a model-based product synthesis/design stage and a modelexperiment based further refinement and/or validation stage. In this paper only the first stage is presented. The methodology employs a...... employed to obtain a list of formulations that satisfy constraints representing the desired needs (target properties). Through a conceptual case study dealing with the design of a sunscreen lotion, the application of this new methodology is illustrated....
A Systematic Methodology for Design of Emulsion Based Chemical Products
DEFF Research Database (Denmark)
Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul
A systematic methodology for emulsion based chemical product design is presented. The methodology employs a model-based product synthesis/design stage and a modelexperiment based further refinement and/or validation stage. In this paper only the first stage is presented. The methodology employs a...... employed to obtain a list of formulations that satisfy constraints representing the desired needs (target properties). Through a conceptual case study dealing with the design of a sunscreen lotion, the application of this new methodology is illustrated....
Ataei, Sh; Mahmud, Z.; Khalid, M. N.
2014-04-01
The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.
International Nuclear Information System (INIS)
The students learning outcomes clarify what students should know and be able to demonstrate after completing their course. So, one of the issues on the process of teaching and learning is how to assess students' learning. This paper describes an application of the dichotomous Rasch measurement model in measuring the cognitive process of engineering students' learning of mathematics. This study provides insights into the perspective of 54 engineering students' cognitive ability in learning Calculus III based on Bloom's Taxonomy on 31 items. The results denote that some of the examination questions are either too difficult or too easy for the majority of the students. This analysis yields FIT statistics which are able to identify if there is data departure from the Rasch theoretical model. The study has identified some potential misfit items based on the measurement of ZSTD where the removal misfit item was accomplished based on the MNSQ outfit of above 1.3 or less than 0.7 logit. Therefore, it is recommended that these items be reviewed or revised to better match the range of students' ability in the respective course.
Shein, E. V.
2015-07-01
The formation, development, and some problems of the current physically based models of water and solute transfer are considered in this review. These models appeared about a half century ago. They were based on the basic laws of soil physics and other branches of soil science (laws of balance, transfer, diffusion, hydrodynamic dispersion, etc.) described by the corresponding equations and programs and supported by the experimental data in the form of physically based parameters. At present, one of the main problems in the development, adaptation, and application of these models is that the current and future mathematical models should rest upon the experimental support with a clear physical basis characterizing the nature of the phenomenon described. This experimental support enables creating research models, drawing conceptual conclusions, and, hence, understanding, analyzing, and managing soil processes. This is apparently possible only if the set of methods for the experimental support of models is substantiated, preferably in direct physical experiments and under field conditions close to the future model prognoses.
A "Mathematics Background Check"
Hubisz, John
2009-01-01
Early in my career someone else reported that the best indicator of success in calculus-based physics (CBP) at our school was whether students had taken mathematics in a certain region of New Brunswick. I sat down with a very longtime mathematics teacher and asked him what he thought students should know in mathematics after high school to succeed…
Action-Based Digital Tools: Mathematics Learning in 6-Year-Old Children
Dejonckheere, Peter J. N.; Desoete, Annemie; Fonck, Nathalie; Roderiguez, Dave; Six, Leen; Vermeersch, Tine; Vermeulen, Lies
2014-01-01
Introduction: In the present study we used a metaphorical representation in order to stimulate the numerical competences of six-year-olds. It was expected that when properties of physical action are used for mathematical thinking or when abstract mathematical thinking is grounded in sensorimotor processes, learning gains should be more pronounced…
Ramnarain, Umesh
2014-01-01
A major impediment to problem solving in mathematics in the great majority of South African schools is that disadvantaged students from seriously impoverished learning environments are lacking in the necessary informal mathematical knowledge to develop their own strategies for solving non-routine problems. A randomized pretest-posttest control…
Mathematical Literacy Teachers' Engagement with Contextual Tasks Based on Personal Finance
Bansilal, Sarah; Mkhwanazi, Thokozani; Mahlabela, Patisizwe
2012-01-01
This article reports on a study carried out with a group of 108 practising Mathematical Literacy (ML) teachers who participated in an Advanced Certificate in Education (ACE) programme. The purpose of the qualitative study was to identify and describe the teachers' varying levels of engagement with mathematics tools and resources. The teachers were…
Students' Perceptions of the Learning Environment and Attitudes in Game-Based Mathematics Classrooms
Afari, Ernest; Aldridge, Jill M.; Fraser, Barry J.; Khine, Myint Swe
2013-01-01
We investigated whether the introduction of games into college-level mathematics classes in the United Arab Emirates (UAE) was effective in terms of improving students' perceptions of the learning environment and their attitudes towards of mathematics. A pre-post design involved the administration of English and Arabic versions of two surveys (one…
Powell, Sarah R.
2015-01-01
Over the past two decades, changes in legislation and mathematics standards, along with the increased placement of students with disabilities in general education settings, have resulted in higher expectations for what students with disabilities will be able to know and do related to mathematics. To adequately prepare for the demands of teaching…
The Use of ICT in Kindergarten for Teaching Addition Based on Realistic Mathematics Education
Zaranis, Nicholas
2016-01-01
The purpose of this study is to investigate if information and communications technology (ICT) helps improve kindergarten students' basic mathematical achievement regarding addition. Our research compares the level of mathematical competence of the students taught using our ICT oriented learning method which specifically takes advantage of…
Applying Mathematical Concepts with Hands-On, Food-Based Science Curriculum
Roseno, Ashley T.; Carraway-Stage, Virginia G.; Hoerdeman, Callan; Díaz, Sebastián R.; Geist, Eugene; Duffrin, Melani W.
2015-01-01
This article addresses the current state of the mathematics education system in the United States and provides a possible solution to the contributing issues. As a result of lower performance in primary mathematics, American students are not acquiring the necessary quantitative literacy skills to become successful adults. This study analyzed the…
Mindfulness-based cognitive therapy to treat multiple chemical sensitivities
DEFF Research Database (Denmark)
Skovbjerg, S; Hauge, Christian Riis; Rasmussen, Alice;
2012-01-01
of an 8-week mindfulness-based cognitive therapy program (MBCT) for adults with MCS and to evaluate possible effects on psychological distress and illness perception. The study design was a randomized clinical trial. The MBCT programme comprised 8 weekly sessions of 2½ hours. Forty-two adults were......Multiple chemical sensitivities (MCS) is a medically unexplained and socially disabling disorder characterized by negative health effects attributed to exposure to common airborne chemicals. Currently, there is no evidence-based treatment. The objectives of the study were to assess the feasibility...... screened for eligibility and 37 were included. Mean age of the participants was 51.6 years, 35 (94.6%) were female and 21 (56.8%) were unemployed. Measures of psychological distress and illness perceptions were assessed at baseline, 4 weeks, 8 weeks and at 3 months follow-up. No significant differences in...
Guided and Team-Based Learning for Chemical Information Literacy
Loo, Jeffery L.
2013-01-01
This case study recounts a process of course design, conduct, and evaluation for a single-session chemical information literacy class using guided and team-based learning. This approach incorporates active learning, worked examples, process worksheets, and POGIL elements. The instruction followed an iterative cycle of learning exercises whereby (1) the instructor introduces an information problem or task through a short presentation, (2) student teams collaboratively work through process work...
Van Eck, Richard
This study looked at the effect of contextual advisement and competition on transfer of mathematics skills in a computer-based instructional simulation game and simulation in which game participants helped their "aunt and uncle" fix up a house. Competition referred to whether or not the participant was playing against a computer character, and…
Kartashev, Alexander; Safonov, Evgeniy; Kartasheva, Marina
2011-01-01
The mathematical model describing the operation of the installation of selfcontained heating and hot water supply based on solar thermal collector with the system of accumulation of heat energy, monitoring and control of thermal conditions of building is developed. Modeling of operation of the installation in different conditions is realized.
Tandiseru, Selvi Rajuaty
2015-01-01
The problem in this research is the lack of creative thinking skills of students. One of the learning models that is expected to enhance student's creative thinking skill is the local culture-based mathematical heuristic-KR learning model (LC-BMHLM). Heuristic-KR is a learning model which was introduced by Krulik and Rudnick (1995) that is the…
Gann, Linda
2013-01-01
The research centered on secondary mathematics teachers' beliefs, attitudes, knowledge base, and practices in meeting the academic and language needs of English language learners. Using socio-cultural theory and social practice theory to frame the study, the research design employed a mixed methods approach incorporating self-reported…
Cheriani, Cheriani; Mahmud, Alimuddin; Tahmir, Suradi; Manda, Darman; Dirawan, Gufran Darma
2015-01-01
This study aims to determine the differences in learning output by using Problem Based Model combines with the "Buginese" Local Cultural Knowledge (PBL-Culture). It is also explores the students activities in learning mathematics subject by using PBL-Culture Models. This research is using Mixed Methods approach that combined quantitative…
Murni, Atma; Sabandar, Jozua; Kusumah, Yaya S.; Kartasamita, Bana Goerbana
2013-01-01
The aim of this study is to know the differences of enhancement in mathematical problem solving ability (MPSA) between the students who received soft skill- based metacognitive learning (SSML) with the students who got conventional learning (CL). This research is a quasi experimental design with pretest-postest control group. The population in…
BouJaoude, Saouma B.; Jurdak, Murad E.
2010-01-01
The purposes of this study were to understand the nature of discourse in terms of knowledge types and cognitive process, source of utterances (student or teacher), and time use in microcomputer-based labs (MBL) and verification type labs (VTL) and to gain an understanding of the role of MBL in promoting mathematization. The study was conducted in…
Tseng, Kuo-Hung; Chang, Chi-Cheng; Lou, Shi-Jer; Chen, Wen-Ping
2013-01-01
Many scholars claimed the integration of science, technology, engineering and mathematics (STEM) education is beneficial to the national economy and teachers and institutes have been working to develop integrated education programs. This study examined a project-based learning (PjBL) activity that integrated STEM using survey and interview…
Sapunov, Valentin; Dikinis, Alexandr; Voronov, Nikolai
2014-05-01
Russian Federation having giant area has low concentration of land meteorological check points. Net of monitoring is not enough for effective forecast and prediction of weather dynamics and extremely situations. Under increase of extremely situations and incidents - hurricanes et al (two times from begin of XXI century) reconstruction and "perestroika" of monitoring net is needful and necessary. The basis of such a progress is distant monitoring using planes and satellites adding land contact monitoring base on efforts of existed points and stations. Interaction of contact and distant views may make hydro meteorological data and prediction more fine and significant. Tradition physical methods must be added by new biological methods of modern study. According to gotten researches animal are able to predict extremely hazards of natural and anthropogenic nature basing of interaction between biological matter and probable physical field that is under primary study. For example it was animals which forecasted dropping of Chelyabinsk meteorite of 2013. Adding of biological indication with complex of meteorological data may increase significance of hazard prediction. The uniting of all data and approaches may become basis of proposed mathematical hydro meteorological weather models. Introduction to practice reported complex methods may decrease of loss from hydro meteorological risks and hazards and increase stability of country economics.
Problem-based learning in teaching Mathematics at the science-art centers
Directory of Open Access Journals (Sweden)
Ali İhsan BORAN
2008-06-01
Full Text Available It is known that approximately 5 percent of the population of a community is made up of gifted and mentally deficient people. Half of this includes the gifted and talented people. Yet, until now no due importance has been given to the education of gifted and talented people in our country. But recently this negligence has started to change with the foundation of independent special education centers, called “science and arts centers”, which specially serve to gifted students in pre-school, primary, and high school period in order to make them aware of their individual skills and use their full capacity by improving it without interrupting their formal education. These entirely new centers are facing a lot of problems, however. One of the major problems is the lack of exemplary activities to enable students to use and improve their potentials effectively. In this article, the role and importance of Problem Based Learning (PBL in teaching mathematics to gifted students is dealt with stressing its reasons and some sample Problem Based Learning (PBL activities applied in Malatya Science and Arts Center are given.
International Nuclear Information System (INIS)
The irradiation of materials and products 'off carrier' has historically been performed using a 'drop-and-read' methodology whereby the radioisotope source is raised and lowered repeatedly until the desired absorbed dose is achieved. This approach is time consuming from both a manpower and process perspective. Static irradiation-based processes can also be costly because of the need for repeated experimental verification of target dose delivery. In our paper we address the methods used for predicting Ethicon Endo Surgery's (EES's) off-carrier absorbed dose distributions. The scenarios described herein are complex due to the fact that the on-carrier process stream exhibits a wide range of densities and dose rates. The levels of observed complexity are attributed to the 'just-in-time' production strategy and its related requirements as they apply to the programming of EES's cobalt-60 irradiators. Validation of off-carrier processing methodologies requires sophisticated parametric-based systems utilizing mathematical algorithms that predict off-carrier absorbed dose rate relative to the on-carrier process stream components. Irradiation process simulation is achieved using a point kernel computer modeling approach, coupled with database generation and maintenance. Dose prediction capabilities are validated via routine and transfer standard dosimetry
Luther, Kenneth H.
2012-01-01
Mathematical modeling of groundwater flow is a topic at the intersection of mathematics and geohydrology and is rarely encountered in undergraduate mathematics. However, this subject is full of interesting and meaningful examples of truly "applied" mathematics accessible to undergraduates, from the pre-calculus to advanced mathematics levels. This…
Canelas, Ricardo; Heleno, Sandra; Pestana, Rita; Ferreira, Rui M. L.
2014-05-01
The objective of the present work is to devise a methodology to validate 2DH shallow-water models suitable to simulate flow hydrodynamics and channel morphology. For this purpose, a 2DH mathematical model, assembled at CEHIDRO, IST, is employed to model Tagus river floods over a 70 km reach and Synthetic Aperture Radar (SAR) images are collected to retrieve planar inundation extents. The model is suited for highly unsteady discontinuous flows over complex, time-evolving geometries, employing a finite-volume discretization scheme, based on a flux-splitting technique incorporating a reviewed version of the Roe Riemann solver. Novel closure terms for the non-equilibrium sediment transport model are included. New boundary conditions are employed, based on the Riemann variables associated the outgoing characteristic fields, coping with the provided hydrographs in a mathematically coherent manner. A high resolution Digital Elevation Model (DEM) is used and levee structures are considered as fully erodible elements. Spatially heterogeneous roughness characteristics are derived from land-use databases such as CORINE LandCover 2006. SAR satellite imagery of the floods is available and is used to validate the simulation results, with particular emphasis on the 2000/2001 flood. The delimited areas from the satellite and simulations are superimposed. The quality of the adjustment depends on the calibration of roughness coefficients and the spatial discretization of with small structures, with lengths at the order of the spatial discretization. Flow depths and registered discharges are recovered from the simulation and compared with data from a measuring station in the domain, with the comparison revealing remarkably high accuracy, both in terms of amplitudes and phase. Further inclusion of topographical detail should improve the comparison of flood extents regarding satellite data. The validated model was then employed to simulate 100-year floods in the same reach. The
Chemical Cytometry: Fluorescence-Based Single-Cell Analysis
Cohen, Daniella; Dickerson, Jane A.; Whitmore, Colin D.; Turner, Emily H.; Palcic, Monica M.; Hindsgaul, Ole; Dovichi, Norman J.
2008-07-01
Cytometry deals with the analysis of the composition of single cells. Flow and image cytometry employ antibody-based stains to characterize a handful of components in single cells. Chemical cytometry, in contrast, employs a suite of powerful analytical tools to characterize a large number of components. Tools have been developed to characterize nucleic acids, proteins, and metabolites in single cells. Whereas nucleic acid analysis employs powerful polymerase chain reaction-based amplification techniques, protein and metabolite analysis tends to employ capillary electrophoresis separation and ultrasensitive laser-induced fluorescence detection. It is now possible to detect yoctomole amounts of many analytes in single cells.
Institute of Scientific and Technical Information of China (English)
SHU Linsen; CAO Huajun; LI Xianchong; ZHANG Chenglong; LI Yuxia
2015-01-01
The current researches on the tooth surface mathematical equations and the theory of gearing malnly pay attention to the ordinary type worm gear set (e.g., ZN, ZA, or ZK). The research of forming mechanism and three-dimensional modeling method for the double pitch worm gear set is not enough. So there are some difficulties in mathematical model deducing and geometry modeling of double pitch ZN-type worm gear set based on generation mechanism. In order to establish the mathematical model and the precise geometric model of double pitch ZN-type worm gear set, the structural characteristics and generation mechanism of the double pitch ZN-type worm gear set are investigated. Mathematical model of the ZN-type worm gear set is derived based on its generation mechanism and the theory of gearing. According to the mathematical model of the worm gear set which has been developed, a geometry modeling method of the double pitch ZN-type worm and worm gear is presented. Furthermore, a geometrical precision calculate method is proposed to evaluate the geometrical quality of the double pitch worm gear set. As a result, the maximum error is less than 6´10–4 mm in magnitude, thus the model of the double pitch ZN-type worm gear set is avallable to meet the requirements of finite element analysis and engineering application. The derived mathematical model and the proposed geometrical modeling method are helpful to guiding the design, manufacture and contact analysis of the worm gear set.
International Nuclear Information System (INIS)
Mathematical model describing conditions of steam generator washing-out by chelates was used to consider problems of modelling of thermal-hydraulic and water-chemical processes in PGV-1000 steam generators. Steam generator is divided into 80 sections because the design features of steam generator are responsible for sufficient irregularities of thermal and hydrodynamic characteristics over its cross section. To describe process kinetics each section is supplied with its own system of differential equations. The structure of hydrodynamic overflows in steam generator volume was determined on the basis of three-dimensional model of steam generator taking into account the nonideal character of displacement. It is concluded that PGV steam generator contains regions, where circulation water flows converge, and where accumulation of impurities is possible
Mathematical modeling and analysis of EDM process parameters based on Taguchi design of experiments
Laxman, J.; Raj, K. Guru
2015-12-01
Electro Discharge Machining is a process used for machining very hard metals, deep and complex shapes by metal erosion in all types of electro conductive materials. The metal is removed through the action of an electric discharge of short duration and high current density between the tool and the work piece. The eroded metal on the surface of both work piece and the tool is flushed away by the dielectric fluid. The objective of this work is to develop a mathematical model for an Electro Discharge Machining process which provides the necessary equations to predict the metal removal rate, electrode wear rate and surface roughness. Regression analysis is used to investigate the relationship between various process parameters. The input parameters are taken as peak current, pulse on time, pulse off time, tool lift time. and the Metal removal rate, electrode wear rate and surface roughness are as responses. Experiments are conducted on Titanium super alloy based on the Taguchi design of experiments i.e. L27 orthogonal experiments.
Study of the Video Monitoring System Image Recognition Solutions Based on Mathematic models
Directory of Open Access Journals (Sweden)
Peilong Xu
2013-01-01
Full Text Available objective: Through establishment a set of image recognition system based on mathematic models, to develop a auto alarm solution for the video monitoring system. Methods: compare the images the video monitoring system collected according to the time sequences. Then after binaryzation and wave filtering, the images were converted into numerical values using autocorrelation function, and the alarm threshold value was confirmed by experiences. Results: Through experiments, the change ratios of the two images before and after image processing were inversely proportional to the autocorrelation function. When the function value is less than 0.8, it indicates that there is an object volumes larger than 1m3 has invaded into 15m distances, and when the function value is less than 0.6, it indicates that there is an object volumes larger than 1m3 has invaded into 30m distances. Conclusion: Through calculation of autocorrelation functions, auto alarm for the images collected by video monitoring system could be effectively realized.
The evaluation of mine geology disasters based on fuzzy mathematics and grey theory
Institute of Scientific and Technical Information of China (English)
L(U) Da-wei; WU Li-rong; LI Zeng-xue
2007-01-01
Mine geology disasters include mine water, mine solid waste, apron and slide,ground collapse sink and underground fracture, etc.. The subject was studied in many ways, and fuzzy mathematics was usually used. It may assure the result and distinguish the dangerous rank of different areas. But it has two defects: The first is the result is not very exact, especially the border; The second is it is short of quantity. Fuzzy mathematics and grey theory were used in order to solve the problem. Firstly, mathematical model was constructed by using grey theory, so as to evaluate and forecast the dangerous rank of mining geology disaster in different areas. Then different areas were analyzed and divided by fuzzy mathematics. By doing these, similitude rules are not only studied but also differences are discriminated. Through the practice it can be known that the result is more accurate than before.
Vula, Eda; Kingji-Kastrati , Jeta; Podvorica, Fitore
2015-01-01
This study analyses the presentation of fractions in Kosovar and Albanian mathematics textbooks designed for students of one to fifth-grade. Physical characteristics of the selected textbooks, the presentation of fractions and the nature of the problems were analysed as well. Findings showed that Albanian mathematics textbooks covered more lessons on fractions than Kosovar textbooks. Textbooks from both countries focus mostly on part whole and operator construction. Also, the majority of prob...
Directory of Open Access Journals (Sweden)
Tim Dunne
2012-10-01
Full Text Available The challenges inherent in assessing mathematical proficiency depend on a number of factors, amongst which are an explicit view of what constitutes mathematical proficiency, an understanding of how children learn and the purpose and function of teaching. All of these factors impact on the choice of approach to assessment. In this article we distinguish between two broad types of assessment, classroom-based and systemic assessment. We argue that the process of assessment informed by Rasch measurement theory (RMT can potentially support the demands of both classroom-based and systemic assessment, particularly if a developmental approach to learning is adopted, and an underlying model of developing mathematical proficiency is explicit in the assessment instruments and their supporting material. An example of a mathematics instrument and its analysis which illustrates this approach, is presented. We note that the role of assessment in the 21st century is potentially powerful. This influential role can only be justified if the assessments are of high quality and can be selected to match suitable moments in learning progress and the teaching process. Users of assessment data must have sufficient knowledge and insight to interpret the resulting numbers validly, and have sufficient discernment to make considered educational inferences from the data for teaching and learning responses.
Post secondary project-based learning in science, technology, engineering and mathematics
Directory of Open Access Journals (Sweden)
Rachel A Ralph
2016-03-01
Full Text Available Project-based learning (PjBL - to distinguish from problem-based learning - PBL has become a recurrent practice in K-12 classroom environments. As PjBL has become prominent in K-12 classrooms, it has also surfaced in post-secondary institutions. The purpose of this paper is to examine the research that has studied a variety of science, technology, engineering and mathematic subjects using PjBL in post-secondary classrooms. Eleven articles (including qualitative, quantitative and mixed methods were included. The format includes: an introduction and background (which defines PjBL and STEM, research methods, quality appraisal used, results, and a discussion, future research and a conclusion. Two tables and two figures are included. In this paper, theoretical backgrounds and key terms were identified, followed by a literature review discussing four themes: content knowledge, interdisciplinary skills, collaboration and skill development for future education and careers. Results suggested that there is a positive connection between content knowledge learning and PjBL in collaborative settings. Additionally, some negative perceptions arose regarding teamwork situations. Interdisciplinary skills were achieved, but quite limited in post-secondary classrooms. PjBL and STEM were perceived to be important for future education and careers. Future research needs to be completed and institutional curriculum changes informed by the results of this research need to occur to further explore interdisciplinary courses and the use of PjBL.
Driessche, Pauline; Wu, Jianhong
2008-01-01
Based on lecture notes of two summer schools with a mixed audience from mathematical sciences, epidemiology and public health, this volume offers a comprehensive introduction to basic ideas and techniques in modeling infectious diseases, for the comparison of strategies to plan for an anticipated epidemic or pandemic, and to deal with a disease outbreak in real time. It covers detailed case studies for diseases including pandemic influenza, West Nile virus, and childhood diseases. Models for other diseases including Severe Acute Respiratory Syndrome, fox rabies, and sexually transmitted infections are included as applications. Its chapters are coherent and complementary independent units. In order to accustom students to look at the current literature and to experience different perspectives, no attempt has been made to achieve united writing style or unified notation. Notes on some mathematical background (calculus, matrix algebra, differential equations, and probability) have been prepared and may be downlo...
Predictive spectroscopy and chemical imaging based on novel optical systems
Nelson, Matthew Paul
1998-10-01
This thesis describes two futuristic optical systems designed to surpass contemporary spectroscopic methods for predictive spectroscopy and chemical imaging. These systems are advantageous to current techniques in a number of ways including lower cost, enhanced portability, shorter analysis time, and improved S/N. First, a novel optical approach to predicting chemical and physical properties based on principal component analysis (PCA) is proposed and evaluated. A regression vector produced by PCA is designed into the structure of a set of paired optical filters. Light passing through the paired filters produces an analog detector signal directly proportional to the chemical/physical property for which the regression vector was designed. Second, a novel optical system is described which takes a single-shot approach to chemical imaging with high spectroscopic resolution using a dimension-reduction fiber-optic array. Images are focused onto a two- dimensional matrix of optical fibers which are drawn into a linear distal array with specific ordering. The distal end is imaged with a spectrograph equipped with an ICCD camera for spectral analysis. Software is used to extract the spatial/spectral information contained in the ICCD images and deconvolute them into wave length-specific reconstructed images or position-specific spectra which span a multi-wavelength space. This thesis includes a description of the fabrication of two dimension-reduction arrays as well as an evaluation of the system for spatial and spectral resolution, throughput, image brightness, resolving power, depth of focus, and channel cross-talk. PCA is performed on the images by treating rows of the ICCD images as spectra and plotting the scores of each PC as a function of reconstruction position. In addition, iterative target transformation factor analysis (ITTFA) is performed on the spectroscopic images to generate ``true'' chemical maps of samples. Univariate zero-order images, univariate first
Chemical sensors based on molecularly modified metallic nanoparticles
International Nuclear Information System (INIS)
This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)
Mathematical points as didactical ideas
DEFF Research Database (Denmark)
Mogensen, Arne
2012-01-01
Mathematics teaching in Denmark was recently recommended better organized in sequences with clear mathematical pedagogical goals and a focus on mathematical points. In this paper I define a mathematical point and inform on coding of transcripts in a video based Danish research study on grade 8...
Mathematical Footprints Discovering Mathematics Everywhere
Pappas, Theoni
1999-01-01
MATHEMATICAL FOOTPRINTS takes a creative look at the role mathematics has played since prehistoric times, and will play in the future, and uncovers mathematics where you least expect to find it from its many uses in medicine, the sciences, and its appearance in art to its patterns in nature and its central role in the development of computers. Pappas presents mathematical ideas in a readable non-threatening manner. MATHEMATICAL FOOTPRINTS is another gem by the creator of THE MATHEMATICS CALENDAR and author of THE JOY OF MATHEMATICS. "Pappas's books have been gold mines of mathematical ent
DEFF Research Database (Denmark)
Yuan, Zhihong; Chen, Bingzhen; Sin, Gürkan;
2012-01-01
Significant progress in the area of simultaneous design and control for chemical processes has been achieved and various methodologies have been put forward to address this issue over the last several decades. These methods can be classified in two categories (1) controllability indicator......‐based frameworks that are capable of screening alternative designs, and (2) optimization‐based frameworks that integrate the process design and control system design. The major objective is to give an up‐to‐date review of the state‐of‐the‐art and progress in the challenging area of optimization‐based simultaneous...... design and control. First, motivations and significances of simultaneous design and control are illustrated. Second, a general classification of existing methodologies of optimization‐based simultaneous design and control is outlined. Subsequently, the mathematical formulations and relevant theoretical...
Directory of Open Access Journals (Sweden)
Farideh Kamali-Mohammadzadeh
2014-02-01
Full Text Available Nowadays, one of the most important issues which have drawn the attention of educational planners is how education system should face the opportunities and threats arising from development of information and communication technology so as to make the best use of them. Teaching and learning mathematics by help of information technology is a modern approach. This paper attempts to study the effect of using Crocodile ICT 605 software in teaching flowchart, based on constructivism and in line with behavioral goals, on progress of students in mathematics. For this purpose, 55 girl students of the third year of high school in the field of mathematics in Tehran were selected by quasi-experimental method. The results obtained by the above mentioned software and teacher-made test as well as statistical results (with significance level of 0.05 revealed that the use of Crocodile ICT 605 software in teaching flowchart does not help the mathematics progress of students in the level of cognitive knowledge, but is effective in meta-knowledge level of students.
Reys, Robert; Reys, Rustin
2011-01-01
In their dual roles as mathematics teachers and tennis coaches, the authors have worked with tennis players who have never thought about how a knowledge of mathematics might help them become "better" tennis players. They have also worked with many mathematics students who have never considered how much mathematics is associated with tennis. This…
Photonic crystal fiber based chloride chemical sensors for corrosion monitoring
Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar
2016-04-01
Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.
Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications
Li, Jing; Lu, Yijiang
2009-01-01
A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.
Nagra/PSI Chemical Thermodynamic Data Base 01/01
International Nuclear Information System (INIS)
The Nagra/PSI Chemical Thermodynamic Data Base has been updated to support performance assessments of the planned Swiss repositories for radioactive waste. The update from version 05/92 to 01/01 involved major revisions for most of the actinides and fission products. Altogether, more than 70% of the database contents have been revised. Data for U, Np, Pu, Am and Tc recommended by the NEA TDB project were considered in the update. Thermodynamic data for Th, Sn, Eu, Pd, Al, and solubility and metal complexation of sulphides and silicates were extensively reviewed. Data for Zr, Ni and Se were examined less rigorously as these elements are currently being reviewed in phase II of the NEA TDB project. Our experiences from this two year team effort can be summarised as follows. Detailed in-house reviews and critical appraisal of NEA recommendations greatly improved the chemical consistency and quality of the selected data. On the other hand, we could discern major gaps in the data, especially missing carbonate complexes. In some systems, e.g. Th(IV)-H2O and U(IV)-H2O, experimental data could not be described by a unique set of thermodynamic constants. There, a pragmatic approach based on solubility data was chosen for application to performance assessment. The electronic version of our database and information concerning its full documentation is available on our PSI web site (http://www.psi.ch/les). (orig.)
Zirconia-based solid state chemical gas sensors
Zhuiykov, S
2000-01-01
This paper presents an overview of chemical gas sensors, based on solid state technology, that are sensitive to environmental gases, such as O sub 2 , SO sub x , NO sub x , CO sub 2 and hydrocarbons. The paper is focussed on performance of electrochemical gas sensors that are based on zirconia as a solid electrolyte. The paper considers sensor structures and selection of electrode materials. Impact of interfaces on sensor performance is discussed. This paper also provides a brief overview of electrochemical properties of zirconia and their effect on sensor performance. Impact of auxiliary materials on sensors performance characteristics, such as sensitivity, selectivity, response time and recovery time, is also discussed. Dual gas sensors that can be applied for simultaneous monitoring of the concentration of both oxygen and other gas phase components, are briefly considered
Zulfaneti, Rismen, Sefna; Suryani, Mulia
2016-02-01
The previous research showed that the teachers of the fourth grade at elementary school in West Sumatra need lesson plan and teaching materials which integrated with character education especially on mathematics subject. Teachers need teaching materials which encompasses the daily life problems (contextual) so that, it can increase students' understanding of mathematics. Realistic mathematics education is a solution to these problems. The aims of the research are to develop learning equipment, i. e lesson plan sand valid worksheets. Development model referred to the Plomp development model which consists of three phase namely preliminary research, prototyping phase, and assessment phase. However, in this research, it is only presented the results in the expert review which is in the part of prototyping phase. The instrument was the validation worksheet. Expert stated that each of lesson plan and students' worksheet were in valid criterion
Directory of Open Access Journals (Sweden)
Dinh An Nguyen
2012-07-01
Full Text Available Many of the Proton Exchange Membrane Fuel Cell (PEMFC models proposed in the literature consist of mathematical equations. However, they are not adequately practical for simulating power systems. The proposed model takes into account phenomena such as activation polarization, ohmic polarization, double layer capacitance and mass transport effects present in a PEM fuel cell. Using electrical analogies and a mathematical modeling of PEMFC, the circuit model is established. To evaluate the effectiveness of the circuit model, its static and dynamic performances under load step changes are simulated and compared to the numerical results obtained by solving the mathematical model. Finally, the applicability of our model is demonstrated by simulating a practical system.
Leifer, M S
2015-01-01
In this essay, I argue that mathematics is a natural science---just like physics, chemistry, or biology---and that this can explain the alleged "unreasonable" effectiveness of mathematics in the physical sciences. The main challenge for this view is to explain how mathematical theories can become increasingly abstract and develop their own internal structure, whilst still maintaining an appropriate empirical tether that can explain their later use in physics. In order to address this, I offer a theory of mathematical theory-building based on the idea that human knowledge has the structure of a scale-free network and that abstract mathematical theories arise from a repeated process of replacing strong analogies with new hubs in this network. This allows mathematics to be seen as the study of regularities, within regularities, within ..., within regularities of the natural world. Since mathematical theories are derived from the natural world, albeit at a much higher level of abstraction than most other scientif...
Wilfredo, Angulo
2014-01-01
We present some qualitative aspects concerning the solution to the mathematical model describing the dynamical behavior of the reversible chemical reaction SO2(g)+1/2O2(g)SO3(g) carried out in a catalytic reactor used in the process of sulfuric acid production.
Gene expression module-based chemical function similarity search
Li, Yun; Hao, Pei; Zheng, Siyuan; Tu, Kang; Fan, Haiwei; Zhu, Ruixin; Ding, Guohui; Dong, Changzheng; Wang, Chuan; Li, Xuan; Thiesen, H.-J.; Chen, Y. Eugene; Jiang, HuaLiang; Liu, Lei; Li, Yixue
2008-01-01
Investigation of biological processes using selective chemical interventions is generally applied in biomedical research and drug discovery. Many studies of this kind make use of gene expression experiments to explore cellular responses to chemical interventions. Recently, some research groups constructed libraries of chemical related expression profiles, and introduced similarity comparison into chemical induced transcriptome analysis. Resembling sequence similarity alignment, expression pat...
Key ideas in teaching mathematics: research-based guidance for ages 9-19
Watson, Anne; Jones, Keith; Pratt, Dave
2013-01-01
Big ideas in the mathematics curriculum for older school students, especially those that are hard to learn and hard to teach, are covered in this book. It is designed to be a first port of call for research about teaching big ideas for students from 9-19 and also has implications for a wider range of students. These are the ideas that really matter, that students get stuck on, and that can be obstacles to future learning. The book shows how students learn mathematics, why they sometimes get t...
Ozer, Eren; Sezer, Renan
2014-01-01
This study offers a comparative analysis of questions found in Turkish, Singaporean, and American mathematics textbooks and workbooks based on topics covered in the 8th grade mathematics curriculum in Turkey. To this end, the study utilizes the 3-dimensional framework developed by Li. When the questions in the textbooks and workbooks…
Barriteau Phaire, Candace
2013-01-01
The teaching and learning of mathematics has been the subject of debate for over 30 years and the most recent reform efforts are in response to concerns regarding the mathematical competence of students in the United States (Ball, Hill, & Bass, 2005; Battista, 1994; Cavanagh, 2008). Standards-based Instructional Materials (SBIM) allows…
Yuliani, Kiki; Saragih, Sahat
2015-01-01
The purpose of this research was to: 1) development of learning devices based guided discovery model in improving of understanding concept and critical thinking mathematically ability of students at Islamic Junior High School; 2) describe improvement understanding concept and critical thinking mathematically ability of students at MTs by using…
Kouropoulos, Giorgos
2014-01-01
At this article will be created a software written in visual basic for efficiency and penetration calculation in a fibrous filter medium for given values of particles diameter that are retained in the filter. Initially, will become report of mathematical models of air filtration in fibrous filters media and then will develop the code and the graphical interface of application, that are the base for software creation in the visual basic platform.
Cheriani Cheriani; Alimuddin Mahmud; Suradi Tahmir; Darman Manda; Gufran Darma Dirawan
2015-01-01
This study aims to determine the differences in learning output by using Problem Based Model combines with the “Buginese” Local Cultural Knowledge. (PBL-Culture) It is also explores the students activities in learning mathematics subject by using PBL-Culture Models. This research is using Mixed Methods approach that combined quantitative and qualitative methods and Sequential Explanatory Design (SED) Models that implemented at junior high school, at Bone Regency in South Sulawesi Province. Th...
Pawlus, Witold; Karimi, Hamid Reza; Robbersmyr, Kjell G.
2010-01-01
This paper investigates the usability of spring which exhibit nonlinear force-deflection characteristic in the area of mathematical modeling of vehicle crash. We present a method which allows us to obtain parameters of the spring-mass model basing on the full-scale experimental data analysis. Since vehicle collision is a dynamic event, it involves such phenomena as rebound and energy dissipation. Three different spring unloading scenarios (elastic, plastic, and elasto-plastic) are covered and...
2011-01-01
This paper investigates the usability of spring which exhibit nonlinear force-deflection characteristic in the area of mathematical modeling of vehicle crash. We present a method which allows us to obtain parameters of the spring-mass model basing on the full-scale experimental data analysis. Since vehicle collision is a dynamic event, it involves such phenomena as rebound and energy dissipation. Three different spring unloading scenarios (elastic, plastic, and elasto-plastic) are covered and...
Salar Faramarzi; Maryam Samadi; Ahmad Yarmohammadian; Salman Dezhara
2014-01-01
Target: With advances in cognitive neuroscience and the developing connection between neuroscience and education in recent years, new windows has been opened in the realm of teaching and learning for the education experts. So education has vastly benefited from the results of researches in neuroscience to improve learning. The study strived to investigate the effectiveness of “brain based teaching” on the executive functions of the students with mathematics learning disability in Isfahan city...
Farideh Kamali-Mohammadzadeh; Mohammad-Hassan Behzadi; Ahmad Shahvarani; Farhad Hosseinzadeh-Lotfi
2014-01-01
Nowadays, one of the most important issues which have drawn the attention of educational planners is how education system should face the opportunities and threats arising from development of information and communication technology so as to make the best use of them. Teaching and learning mathematics by help of information technology is a modern approach. This paper attempts to study the effect of using Crocodile ICT 605 software in teaching flowchart, based on constructivism and in line wit...
Directory of Open Access Journals (Sweden)
Blaženka Divjak
2011-06-01
Full Text Available Normal 0 21 false false false SH X-NONE X-NONE Information technologies are an integral part of a contemporary society which bases its progress on knowledge being one goal of education. Beside acquiring knowledge, skills and routines, the goal of education is to create a complete individual who can rationally and timely make decisions, purposefully react in new situations and be trained for life-long learning. In order to accomplish all this, it is necessary to make educational process more creative, contemporary and adjusted to new generations of computer literate pupils who demand quicker and more frequent interactions, a lot of information at the same time, generations who quickly acquire rules of computer games. Computer games meeting pedagogical criteria should become an integral part of learning. Teaching with mathematical computer games, which fulfil pedagogical criteria, influences pupils’ motivation, learning, retention and forgetting. This paper provides a review of literature in this field and determines whether the use of mathematical computer games contributes to more efficient realisation of educational goals at all level of education. Furthermore, considering prior research we have attempted to establish whether the use of mathematical games for teaching has an impact on the formation of a positive attitude of pupils of different ages toward the subject of mathematics, their motivation and knowledge acquisition when compared to learning without computer games. Finally, we have analysed different research methods concerning this issue and assessed the impact of pedagogically designed mathematical computer games on the realisation of educational goals and quality improvement of teaching and learning.
Graphene-Based Chemical Vapor Sensors for Electronic Nose Applications
Nallon, Eric C.
chemiresistor device and used as a chemical sensor, where its resistance is temporarily modified while exposed to chemical compounds. The inherent, broad selective nature of graphene is demonstrated by testing a sensor against a diverse set of volatile organic compounds and also against a set of chemically similar compounds. The sensor exhibits excellent selectivity and is capable of achieving high classification accuracies. The kinetics of the sensor's response are further investigated revealing a relationship between the transient behavior of the response curve and physiochemical properties of the compounds, such as the molar mass and vapor pressure. This kinetic information is also shown to provide important information for further pattern recognition and classification, which is demonstrated by increased classification accuracy of very similar compounds. Covalent modification of the graphene surface is demonstrated by means of plasma treatment and free radical exchange, and sensing performance compared to an unmodified graphene sensor. Finally, the first example of a graphene-based, cross-reactive chemical sensor array is demonstrated by applying various polymers as coatings over an array of graphene sensors. The sensor array is tested against a variety of compounds, including the complex odor of Scotch whiskies, where it is capable of perfect classification of 10 Scotch whiskey variations.
Nutti, Ylva Jannok
2013-01-01
The goal of Indigenous education is that it should be approached on the basis of the Indigenous language and culture; this is also the case with Sámi education. The Sámi School Board has stated that all teaching in Sámi schools should be culturally based, despite the fact that Sámi culture-based teaching is not specifically defined. Therefore, teachers themselves must adapt the teaching and as a result, usually no Sámi culture-based mathematics teaching takes place. The aim of ...
Mechanism-based bioanalysis and biomarkers for hepatic chemical stress.
Antoine, D J; Mercer, A E; Williams, D P; Park, B K
2009-08-01
Adverse drug reactions, in particular drug-induced hepatotoxicity, represent a major challenge for clinicians and an impediment to safe drug development. Novel blood or urinary biomarkers of chemically-induced hepatic stress also hold great potential to provide information about pathways leading to cell death within tissues. The earlier pre-clinical identification of potential hepatotoxins and non-invasive diagnosis of susceptible patients, prior to overt liver disease is an important goal. Moreover, the identification, validation and qualification of biomarkers that have in vitro, in vivo and clinical transferability can assist bridging studies and accelerate the pace of drug development. Drug-induced chemical stress is a multi-factorial process, the kinetics of the interaction between the hepatotoxin and the cellular macromolecules are crucially important as different biomarkers will appear over time. The sensitivity of the bioanalytical techniques used to detect biological and chemical biomarkers underpins the usefulness of the marker in question. An integrated analysis of the biochemical, molecular and cellular events provides an understanding of biological (host) factors which ultimately determine the balance between xenobiotic detoxification, adaptation and liver injury. The aim of this review is to summarise the potential of novel mechanism-based biomarkers of hepatic stress which provide information to connect the intracellular events (drug metabolism, organelle, cell and whole organ) ultimately leading to tissue damage (apoptosis, necrosis and inflammation). These biomarkers can provide both the means to inform the pharmacologist and chemist with respect to safe drug design, and provide clinicians with valuable tools for patient monitoring. PMID:19621999
ŞENGÜL, Sare; Öz, Caner
2013-01-01
This research aims to instruct "fractions" to 6th graders in a learning environmentsbased on "Multiple Intelligences Theory" and investigate the effect of such anenvironment on the mathematics achievement and retention levels of 6th graders. Theresearch was conducted in a school in the İzmit Kocaeli area in two Grade 6 sections witha total of 70 students. At the beginning of the study, the experimental groups and controlgroups were given a Preliminary Mathematics Test, "Multiple Intelligences...
Jackson, Karen Latrice Terrell
2014-01-01
Students' perceptions influence their expectations and values. According to Expectations and Values Theory of Achievement Motivation (EVT-AM), students' expectations and values impact their behaviors (Eccles & Wigfield, 2002). This study seeks to find students' perceptions of developmental mathematics in a mastery learning computer-based…
Characterizing Instructor Gestures in a Lecture in a Proof-Based Mathematics Class
Weinberg, Aaron; Fukawa-Connelly, Tim; Wiesner, Emilie
2015-01-01
Researchers have increasingly focused on how gestures in mathematics aid in thinking and communication. This paper builds on Arzarello's (2006) idea of a "semiotic bundle" and several frameworks for describing individual gestures and applies these ideas to a case study of an instructor's gestures in an undergraduate abstract algebra…
Leveraging Quiz-Based Multiple-Prize Web Tournaments for Reinforcing Routine Mathematical Skills
Gonzalez-Tablas, Ana I.; de Fuentes, Jose M.; Hernandez-Ardieta, Jorge L.; Ramos, Benjamin
2013-01-01
In Higher Education Engineering studies, there exists the need of engaging students in performing drill and practice activities with the goal of reinforcing routine mathematical skills. The usual optionality of these tasks entails the risk of students not fulfilling them in an effective way. Although competitive approaches are not a trend in…
Thanheiser, Eva; Browning, Christine; Edson, Alden J.; Kastberg, Signe; Lo, Jane-Jane
2013-01-01
This survey of the literature summarizes and reflects on research findings regarding elementary preservice teachers' (PSTs') mathematics conceptions and the development thereof. Despite the current focus on teacher education, peer-reviewed journals offer a surprisingly sparse insight in these areas. The limited research that exists…
DEFF Research Database (Denmark)
Friesel, Anna
. However, in order to understand complexity of control systems, the students need to possess an analytical understanding of abstract mathematical problems. Our main goal is to illustrate the theory through the robot project, but at the same time we force our students to train their analytical skills by...
Czech Academy of Sciences Publication Activity Database
Balek, V.; Zeleňák, V.; Mitsuhashi, T.; Beckman, I. N.; Haneda, H.; Bezdička, Petr
2002-01-01
Roč. 67, č. 1 (2002), s. 63-72. ISSN 1418-2874 R&D Projects: GA ČR GA104/00/1046 Institutional research plan: CEZ:AV0Z4032918 Keywords : emanation thermal analysis * hydrous titania * mathematical modeling Subject RIV: CA - Inorganic Chemistry Impact factor: 0.598, year: 2002
Digital assessment-driven examples-based mathematics for computer science students
A. Heck; N. Brouwer
2015-01-01
nnovation, inclusion, sharing and diversity are some of the words that briefly and suitably characterize the ICTMT series of biennial international conferences - the International Conference on Technology in Mathematics Teaching. Being the twelfth of a series which began in Birmingham, UK, in 1993,
40 CFR 749.68 - Hexavalent chromium-based water treatment chemicals in cooling systems.
2010-07-01
... Cooling Systems § 749.68 Hexavalent chromium-based water treatment chemicals in cooling systems. (a... distribution in commerce of hexavalent chromium-based water treatment chemicals for use in cooling systems. (d... holds hexavalent chromium-based water treatment chemicals for use in cooling systems. (6) Cooling...
Finite mathematics models and applications
Morris, Carla C
2015-01-01
Features step-by-step examples based on actual data and connects fundamental mathematical modeling skills and decision making concepts to everyday applicability Featuring key linear programming, matrix, and probability concepts, Finite Mathematics: Models and Applications emphasizes cross-disciplinary applications that relate mathematics to everyday life. The book provides a unique combination of practical mathematical applications to illustrate the wide use of mathematics in fields ranging from business, economics, finance, management, operations research, and the life and social sciences.
Chemical Signaling and Functional Activation in Colloidosome-Based Protocells.
Sun, Shiyong; Li, Mei; Dong, Faqin; Wang, Shengjie; Tian, Liangfei; Mann, Stephen
2016-04-01
An aqueous-based microcompartmentalized model involving the integration of partially hydrophobic Fe(III)-rich montmorillonite (FeM) clay particles as structural and catalytic building blocks for colloidosome membrane assembly, self-directed membrane remodeling, and signal-induced protocell communication is described. The clay colloidosomes exhibit size- and charge-selective permeability, and show dual catalytic functions involving spatially confined enzyme-mediated dephosphorylation and peroxidase-like membrane activity. The latter is used for the colloidosome-mediated synthesis and assembly of a temperature-responsive poly(N-isopropylacrylamide)(PNIPAM)/clay-integrated hybrid membrane. In situ PNIPAM elaboration of the membrane is coupled to a glucose oxidase (GOx)-mediated signaling pathway to establish a primitive model of chemical communication and functional activation within a synthetic "protocell community" comprising a mixed population of GOx-containing silica colloidosomes and alkaline phosphatase (ALP)-containing FeM-clay colloidosomes. Triggering the enzyme reaction in the silica colloidosomes gives a hydrogen peroxide signal that induces polymer wall formation in a coexistent population of the FeM-clay colloidosomes, which in turn generates self-regulated membrane-gated ALP-activity within the clay microcompartments. The emergence of new functionalities in inorganic colloidosomes via chemical communication between different protocell populations provides a first step toward the realization of interacting communities of synthetic functional microcompartments. PMID:26923794
Chemistry research and chemical techniques based on research reactors
International Nuclear Information System (INIS)
Chemistry has occupied an important position historically in the sciences associated with nuclear reactors and it continues to play a prominent role in reactor-based research investigations. This Panel of prominent scientists in the field was convened by the International Atomic Energy Agency (IAEA) to assess the present state of such chemistry research for the information of its Member States and others interested in the subject. There are two ways in which chemistry is associated with nuclear reactors: (a) general applications to many scientific fields in which chemical techniques are involved as essential service functions; and (b) specific applications of reactor facilities to the solution of chemical problems themselves. Twenty years of basic research with nuclear reactors have demonstrated a very widespread, and still increasing, demand for radioisotopes and isotopically-labelled molecules in all fields of the physical and biological sciences. Similarly, the determination of the elemental composition of a material through the analytical technique of activation analysis can be applied throughout experimental science. Refs, figs and tabs
Medical Service
2002-01-01
It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546
Limiting factors for carbon based chemical double layer capacitors
Rose, M. Frank; Johnson, C.; Owens, T.; Stevens, B.
1993-01-01
The Chemical Double Layer (CDL) capacitor improves energy storage density dramatically when compared with conventional electrolytic capacitors. When compared to batteries, the CDL Capacitor is much less energy dense; however, the power density is orders of magnitude better. As a result, CDL-battery combinations present an interesting pulse power system with many potential applications. Due to the nature of the CDL it is inherently a low voltage device. The applications of the CDL can be tailored to auxiliary energy and burst mode storages which require fast charge/discharge cycles. Typical of the applications envisioned are power system backup, directed energy weapons concepts, electric automobiles, and electric actuators. In this paper, we will discuss some of the general characteristics of carbon-based CDL technology describing the structure, performance parameters, and methods of construction. Further, analytical and experimental results which define the state of the art are presented and described in terms of impact on applications.
Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction
Directory of Open Access Journals (Sweden)
Aleksandar Sabljic
2004-12-01
Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.
International Nuclear Information System (INIS)
A computer code REACT-Mod which simulates various chemical reactions in an aqueous nitric acid solution involving uranium, plutonium, neptunium, technetium etc. e.g., redox, radiolytic and disproportionation reactions of 68, was developed based on the kinetics model. The numerical solution method adopted in the code are two, a kinetics model totally based on the rate law of which differential equations are solved by the modified Porsing method, and a two-step model based on both the rate law and equilibrium law. Only the former treats 27 radiolytic reactions. The latter is beneficially used to have a quick and approximate result by economical computation. The present report aims not only to explain the concept, chemical reactions treated and characteristics of the model but also to provide details of the program for users of the REACT-Mod code. (author)
Java Based Computer Algorithms for the Solution of a Business Mathematics Model
Directory of Open Access Journals (Sweden)
A. D. Chinedu
2014-10-01
Full Text Available A novel approach is proposed as a framework for working out uncertainties associated with decisions between the choices of leasing and procurement of capital assets in a manufacturing industry. The mathematical concept of the tool is discussed while the technique adopted is much simpler to implement and initialize. The codes were developed in Java-programming language and text-run and executed on a computer system running on Windows 7 operating system. This was done in order to solve a model that illustrates a case study in actuarial mathematics. Meanwhile the solution obtained proves to be stable and proffers to suit the growing frenzy for software for similar recurring cases in business. In addition, it speeds up the computational results. The results obtained using the empirical method is compared with the output and adjudged excellent in terms of accuracy and adoption.
Paranin, Y.; Burmistrov, A.; Salikeev, S.; Fomina, M.
2015-08-01
Basic propositions of calculation procedures for oil free scroll compressors characteristics are presented. It is shown that mathematical modelling of working process in a scroll compressor makes it possible to take into account such factors influencing the working process as heat and mass exchange, mechanical interaction in working chambers, leakage through slots, etc. The basic mathematical model may be supplemented by taking into account external heat exchange, elastic deformation of scrolls, inlet and outlet losses, etc. To evaluate the influence of procedure on scroll compressor characteristics calculations accuracy different calculations were carried out. Internal adiabatic efficiency was chosen as a comparative parameter which evaluates the perfection of internal thermodynamic and gas-dynamic compressor processes. Calculated characteristics are compared with experimental values obtained for the compressor pilot sample.
DEFF Research Database (Denmark)
Friesel, Anna
2013-01-01
This paper presents the contents and the teaching methods used in the fourth semester course - REG4E - an important subject in engineering, namely Control Theory and Dynamical Systems. Control Theory courses in engineering education are usually related to exercises in the laboratory or to projects....... However, in order to understand complexity of control systems, the students need to possess an analytical understanding of abstract mathematical problems. Our main goal is to illustrate the theory through the robot project, but at the same time we force our students to train their analytical skills by...... mandatory exercises including problems of abstract mathematics. This paper describes our effort to motivate students to work with the theory. We conclude with our and students' own opinion on their work during the semester. Ideas for future development of this course are presented....
Harper, Marc; Reddy, Alison Ahlgren
2013-01-01
We show that individual topics and skills can have a dramatic effect on the outcomes of students in various mathematics courses at the University of Illinois. Data from the placement program at Illinois associates a knowledge state, a subset of 182 items and skills that a student is able to complete successfully and repeatedly, with their final grades in a variety of courses from college algebra through multivariate calculus. Using various conditional probabilities and odds ratios, we classif...
Hou, Xin-wen; Yin, Zhi-xuan; Zhang, Jian-Wei; Yuan, Xi-long; Yin, Ming-quan; Li, Qing-Ping; Dong, Jie
2010-01-01
Fuzzy mathematics comprehensive evaluation method is used to evaluate the geological environment suitability of rural urbanization in Qingdao City, China. A total of 5 first-level evaluation factors are selected, including environmental geological condition, geological resources, engineering geological condition, geological disaster and environmental geological problem, and human engineering activity. And there are 27 second-level evaluation factors, such as topography, land type and vegetati...
A QFD-Based Mathematical Model for New Product Development Considering the Target Market Segment
Liang-Hsuan Chen; Cheng-Nien Chen
2014-01-01
Responding to customer needs is important for business success. Quality function deployment provides systematic procedures for converting customer needs into technical requirements to ensure maximum customer satisfaction. The existing literature mainly focuses on the achievement of maximum customer satisfaction under a budgetary limit via mathematical models. The market goal of the new product for the target market segment is usually ignored. In this study, the proposed approach thus consider...
Lee, Chang Jun
2015-01-01
In the fields of researches associated with plant layout optimization, the main goal is to minimize the costs of pipelines and pumping between connecting equipment under various constraints. However, what is the lacking of considerations in previous researches is to transform various heuristics or safety regulations into mathematical equations. For example, proper safety distances between equipments have to be complied for preventing dangerous accidents on a complex plant. Moreover, most rese...
Mathematical modelling of flat and long hot rolling based on finite element methods (FEM
Directory of Open Access Journals (Sweden)
R. Fabík
2012-07-01
Full Text Available The aim of this paper is to critically assess the potential of mathematical modelling which uses finite element method software for solving operation problems in the hot rolling of flat and long products. We focused on concrete issues faced by rolling plants in the Moravian-Silesian region (Czech Republic. The investigation was always combined with field or pilot measurements or laboratory experiments.
Giannessi, Massimo
2010-01-01
In the last years of research, I focused my studies on different physiological problems. Together with my supervisors, I developed/improved different mathematical models in order to create valid tools useful for a better understanding of important clinical issues. The aim of all this work is to develop tools for learning and understanding cardiac and cerebrovascular physiology as well as pathology, generating research questions and developing clinical decision support systems useful for in...
Rasmussen, Svend; Damgaard, Martin
2008-01-01
This paper describes a cost function approach to modelling production and resource use at the level of the individual farm firm. The procedure for deriving the supply function using mathematical programming under fairly general condition of a convex input set is shown, and the model is demonstrated. It is suggested that the model is used as the basic building block in agricultural sector models, the advantage being that the technology is modelled as a production frontier providing better oppo...
Nasini, Stefano
2015-01-01
The thesis deals with the theoretical and practical study of mathematical programming methodologies to the analysis complex networks and their application in economic and social problems. More specifically, it applies models and methods for solving linear and integer programming problems to network models exploiting the matrix structure of such models, resulting in efficient computational procedures and small processing time. As a consequence, it allows the study of larger and more complex n...
... this page: //medlineplus.gov/ency/article/001534.htm Mathematics disorder To use the sharing features on this page, please enable JavaScript. Mathematics disorder is a condition in which a child's ...
Mathematics disorder is a condition in which a child's math ability is far below normal for their ... Children who have mathematics disorder have trouble with simple ... disorder may appear with: Developmental coordination ...
Wright, Vince
2014-01-01
Pirie and Kieren (1989 "For the learning of mathematics", 9(3)7-11, 1992 "Journal of Mathematical Behavior", 11, 243-257, 1994a "Educational Studies in Mathematics", 26, 61-86, 1994b "For the Learning of Mathematics":, 14(1)39-43) created a model (P-K) that describes a dynamic and recursive process by which…
Trinajstić, Nenad; Gutman, Ivan
2002-01-01
A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...
Directory of Open Access Journals (Sweden)
Salar Faramarzi
2014-04-01
Full Text Available Target: With advances in cognitive neuroscience and the developing connection between neuroscience and education in recent years, new windows has been opened in the realm of teaching and learning for the education experts. So education has vastly benefited from the results of researches in neuroscience to improve learning. The study strived to investigate the effectiveness of “brain based teaching” on the executive functions of the students with mathematics learning disability in Isfahan city. Method: To this end, three students with mathematical learning disability were selected using purposeful sampling. In this investing used a single subject with A-B design. Intervention was started after determining the base-line. The “brain based teaching” package was taught to each single participant for 26 intervention sessions. And 1 month after the intervention period follow-up test was performed. The instruments used, included, Raven intelligence test, The Iran key math diagnostic arithmetic and Conner’s questionnaire neuropsychological. The gathered data was analyzed using descriptive statistics and visual analysis. Results: Based on that, Results revealed that during the visual analysis of data graphs for executive function deficits, the study intervention was significantly effective for all 3 participants. Conclusions: This study showed that brain based teaching improves the executive functions of the students and thus, could be used in educating children with learning disabilities.
Plofker, Kim
2009-01-01
Based on extensive research in Sanskrit sources, Mathematics in India chronicles the development of mathematical techniques and texts in South Asia from antiquity to the early modern period. Kim Plofker reexamines the few facts about Indian mathematics that have become common knowledge--such as the Indian origin of Arabic numerals--and she sets them in a larger textual and cultural framework. The book details aspects of the subject that have been largely passed over in the past, including the relationships between Indian mathematics and astronomy, and their cross-fertilizations with Islamic sc
DEFF Research Database (Denmark)
Winsløw, Carl
2015-01-01
Mathematics is studied in universities by a large number of students. At the same time it is a field of research for a (smaller) number of university teachers. What relations, if any, exist between university research and teaching of mathematics? Can research “support” teaching? What research and...... what teaching? In this presentation we propose a theoretical framework to study these questions more precisely, based on the anthropological theory of didactics. As a main application, the links between the practices of mathematical research and university mathematics teaching are examined, in...
Kilpatrick, Jeremy
2014-01-01
This paper addresses the contested way that ethnomathematics has sometimes been received by mathematicians and others and what that disagreement might suggest about issues in mathematics education; namely, (a) the relation of ethnomathematics to academic mathematics; (b) recent efforts to reform secondary school mathematics so that it prepares…
Modeling release of chemicals from multilayer materials into food
Directory of Open Access Journals (Sweden)
Huang Xiu-Ling
2016-01-01
Full Text Available The migration of chemicals from materials into food is predictable by various mathematical models. In this article, a general mathematical model is developed to quantify the release of chemicals through multilayer packaging films based on Fick's diffusion. The model is solved numerically to elucidate the effects of different diffusivity values of different layers, distribution of chemical between two adjacent layers and between material and food, mass transfer at the interface of material and food on the migration process.
Graphene Electronic Device Based Biosensors and Chemical Sensors
Jiang, Shan
Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their
Energy Technology Data Exchange (ETDEWEB)
Mielke, S.P.; Krishnan, V.V. [Biophysics Graduate Group, University of California, Davis (United States)], E-mail: krish@llnl.gov
2004-10-15
Random coil chemical shifts are commonly used to detect protein secondary structural elements in chemical shift index (CSI) calculations. Though this technique is widely used and seems reliable for folded proteins, the choice of reference random coil chemical shift values can significantly alter the outcome of secondary structure estimation. In order to evaluate these effects, we present a comparison of secondary structure content calculated using CSI, based on five different reference random coil chemical shift value sets, to that derived from three-dimensional structures. Our results show that none of the reference random coil data sets chosen for evaluation fully reproduces the actual secondary structures. Among the reference values generally available to date, most tend to be good estimators only of helices. Based on our evaluation, we recommend the experimental values measured by Schwarzinger et al. (2000), and statistical values obtained by Lukin et al. (1997), as good estimators of both helical and sheet content.
Mathematics Education in Argentina
Varsavsky, Cristina; Anaya, Marta
2009-01-01
This article gives an overview of the state of mathematics education in Argentina across all levels, in the regional and world contexts. Statistics are drawn from Mercosur and UNESCO data bases, World Education Indicators and various national time-series government reports. Mathematics results in national testing programmes, Programme for…
Business Mathematics Curriculum.
EASTCONN Regional Educational Services Center, North Windham, CT.
This curriculum guide for teaching business mathematics in the Connecticut Vocational-Technical School System is based on the latest thinking of instructors in the field, suggestions from mathematics authorities, and current instructional approaches in education. The curriculum guide consists of six sections: (1) career relationships and…
Educating mathematics teacher educators
DEFF Research Database (Denmark)
Højgaard, Tomas; Jankvist, Uffe Thomas
2014-01-01
The paper argues for a three-dimensional course design structure for future mathematics teacher educators. More precisely we describe the design and implementation of a course basing itself on: the two mathematical competencies of modelling and problem tackling, this being the first dimension; the...
Panza, Marco
2003-01-01
The aim I am pursuing here is to describe some general aspects of mathematical proofs. In my view, a mathematical proof is a warrant to assert a non-tautological statement which claims that certain objects (possibly a certain object) enjoy a certain property. Because it is proved, such a statement is a mathematical theorem. In my view, in order to understand the nature of a mathematical proof it is necessary to understand the nature of mathematical objects. If we understand them as external e...
Rezaei, Roya
2013-01-01
Demands for efficient, greener, economical and sustainable production of chemicals, materials and energy have led to development of industrial biotechnology as a key technology area to provide such products from bio-based raw materials from agricultural-, forestry- and related industrial residues and by-products. For the bio-based industry, it is essential to develop a number of building blocks or platform chemicals for C2-C6 chemicals and even aromatic chemicals. 3-hydroxypropionaldehyde (3H...
Yilmaz, Suha; Tekin-Dede, Ayse
2016-01-01
Mathematization competency is considered in the field as the focus of modelling process. Considering the various definitions, the components of the mathematization competency are determined as identifying assumptions, identifying variables based on the assumptions and constructing mathematical model/s based on the relations among identified…
DEFF Research Database (Denmark)
Sørensen, John Aasted
2011-01-01
The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able to...... accomplish the following: -Understand and apply formal representations in discrete mathematics. -Understand and apply formal representations in problems within discrete mathematics. -Understand methods for solving problems in discrete mathematics. -Apply methods for solving problems in discrete mathematics......; construct a finite state machine for a given application. Apply these concepts to new problems. The teaching in Discrete Mathematics is a combination of sessions with lectures and students solving problems, either manually or by using Matlab. Furthermore a selection of projects must be solved and handed in...
DEFF Research Database (Denmark)
Blomhøj, Morten
2004-01-01
Developing competences for setting up, analysing and criticising mathematical models are normally seen as relevant only from and above upper secondary level. The general belief among teachers is that modelling activities presuppose conceptual understanding of the mathematics involved. Mathematical...... modelling, however, can be seen as a practice of teaching that place the relation between real life and mathematics into the centre of teaching and learning mathematics, and this is relevant at all levels. Modelling activities may motivate the learning process and help the learner to establish cognitive...... roots for the construction of important mathematical concepts. In addition competences for setting up, analysing and criticising modelling processes and the possible use of models is a formative aim in this own right for mathematics teaching in general education. The paper presents a theoretical...
Directory of Open Access Journals (Sweden)
Halim CEYLAN
2007-02-01
Full Text Available This study develops approximate mathematical expressions for delay components at signalized intersections. Delay components are solved with the coordinate transformation method. The performance indicators for the signalized intersection are determined as an oversaturated and under saturated cases. During the analysis, the steady-state and the deterministic queuing theory are investigated first, and then time-dependent transformation is made. Developed model, called YHM, is applied to an example signalized intersection. Results are compared with the current situation and the Webster method. YHM is improved the intersection performance by about 500 % for this example. Moreover, signal parameters are significantly differs from the current and Webster signal control.
Directory of Open Access Journals (Sweden)
Vijay Nehra
2014-04-01
Full Text Available A large number of diverse engineering applications are frequently modeled using different approaches, viz., a differential equation or by a transfer function and state space. All these descriptions provide a great deal of information about the system, such as stability of the system, its step or impulse response, and its frequency response. The present paper addresses different approaches used to derive mathematical models of first and second order system, developing MATLAB script implementation and building a corresponding Simulink model. The dynamic analysis of electric circuit and system using MATLAB/Simulink has been investigated using different approaches for chosen system parameters.
Özcan Dülger
2014-01-01
Predicting Mathematics 1 course success of students is very important to prepare them before the semester. It is difficult to obtain solution because of the non-linear property of data set. Fuzzy logic is one of the common methods for the problems which involve numeric values. In fuzzy logic, it is important to determine membership functions and their parameter's values correctly. This can be done by an expert or can be learned with a data set. In this study, we aimed to predict the Mathemati...
Semi-Automated Correction Tools for Mathematics-Based Exercises in MOOC Environments
Directory of Open Access Journals (Sweden)
Alberto Corbi
2015-06-01
Full Text Available Massive Open Online Courses (MOOCs allow the participation of hundreds of students who are interested in a wide range of areas. Given the huge numbers enrolled, it is almost impossible to give complex homework to students and have it carefully corrected and reviewed by a tutor or assistant professor. In this paper, we present a software framework that aims at assisting teachers in MOOCs during correction tasks for mathematics exercises. This framework might suit maths, physics or technical subjects. As a test experience, we apply it to 300+ physics homework bulletins from 80+ students. Test results show our solution can prove very useful in guiding assistant teachers during correction shifts.
Mathematical modeling and computational intelligence in engineering applications
Silva Neto, Antônio José da; Silva, Geraldo Nunes
2016-01-01
This book brings together a rich selection of studies in mathematical modeling and computational intelligence, with application in several fields of engineering, like automation, biomedical, chemical, civil, electrical, electronic, geophysical and mechanical engineering, on a multidisciplinary approach. Authors from five countries and 16 different research centers contribute with their expertise in both the fundamentals and real problems applications based upon their strong background on modeling and computational intelligence. The reader will find a wide variety of applications, mathematical and computational tools and original results, all presented with rigorous mathematical procedures. This work is intended for use in graduate courses of engineering, applied mathematics and applied computation where tools as mathematical and computational modeling, numerical methods and computational intelligence are applied to the solution of real problems.
Chase, Norma
2011-11-01
Data spanning fifteen semesters and including more than 1200 students showed far less than the anticipated difference in performance between students with quite diverse levels of physics preparation. Students ranged from those with no prior physics course work to those with two or more years of HS physics and prior courses in college physics. Less prior physics training frequently coincided with better performance in the first calculus-based course. Preparation in mathematics, on the other hand, appeared critically important; students at the extremes of the math preparation spectrum were concentrated at the corresponding extremes of the physics grade distribution.
Mentoring in mathematics education
Hyde, Rosalyn
2013-01-01
Designed to support both teachers and university-based tutors in mentoring pre-service and newly qualified mathematics teachers at both primary and secondary levels, Mentoring Mathematics Teachers offers straightforward practical advice that is based on practice, underpinned by research, and geared specifically towards this challenging subject area.Developed by members of The Association of Mathematics Education Teachers, the authors draw upon the most up-to-date research and theory to provide evidence-based practical guidance. Themes covered include:
基于GUI的高等数学实验教学系统%Teaching System of Advanced Mathematics Experiment Based on GUI
Institute of Scientific and Technical Information of China (English)
唐世星; 刘颖华
2012-01-01
根据高等数学实验教学系统的设计原则与结构，建立了基于Matlab GUI高等数学实验教学系统，并结合具体实例说明了GUI在高等数学实验教学中的应用。%According to design principle and structure of the teaching system of advanced mathematics experiment, the paper established a teaching system of advanced mathematics experiment based on Matlab GUI, and illustrated the application of GUI in teaching of advanced mathematics experiment combined with specific examples.
Mathematical Thinking in Chemistry
Directory of Open Access Journals (Sweden)
José L. Villaveces
2012-05-01
Full Text Available Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffroy's affinity table, Lavoisier's classification of substances and their relationships, Mendeleev's periodic table, Cayley's enumeration of alkanes, Sylvester's association of algebra and chemistry, and Wiener's relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a century of history.
Stöltzner, Michael
Answering to the double-faced influence of string theory on mathematical practice and rigour, the mathematical physicists Arthur Jaffe and Frank Quinn have contemplated the idea that there exists a `theoretical' mathematics (alongside `theoretical' physics) whose basic structures and results still require independent corroboration by mathematical proof. In this paper, I shall take the Jaffe-Quinn debate mainly as a problem of mathematical ontology and analyse it against the backdrop of two philosophical views that are appreciative towards informal mathematical development and conjectural results: Lakatos's methodology of proofs and refutations and John von Neumann's opportunistic reading of Hilbert's axiomatic method. The comparison of both approaches shows that mitigating Lakatos's falsificationism makes his insights about mathematical quasi-ontology more relevant to 20th century mathematics in which new structures are introduced by axiomatisation and not necessarily motivated by informal ancestors. The final section discusses the consequences of string theorists' claim to finality for the theory's mathematical make-up. I argue that ontological reductionism as advocated by particle physicists and the quest for mathematically deeper axioms do not necessarily lead to identical results.
Energy Technology Data Exchange (ETDEWEB)
Partridge, G.P. Jr.
1987-01-01
In the spray dryer, flue gas from a coal-fired boiler is contacted with an atomized lime slurry; during this contact SO/sub 2/ absorbs and reacts with dissolved Ca(OH)/sub 2/. The mathematical model developed in this activity superimposes SO/sub 2/ absorption and reaction phenomena on existing mathematical descriptions of spray dryer operation. The SO/sub 2/ removal appears to occur primarily in the constant rate period where a continuous liquid phase exists in the atomized slurry droplet. The constant rate period proceeds until evaporation has reduced the liquid phase volume to the point where the Ca(OH)/sub 2/ sorbent particles touch and the diffusion paths for reactants are restricted. The SO/sub 2/ absorption flux involves liquid phase as well as gas phase resistances. The liquid phase resistance includes mass transfer and chemical reaction phenomena associated with the absorption and reaction of SO/sub 2/ and Ca(OH)/sub 2/ and the dissolution of Ca(OH)/sub 2/. Instantaneous reaction occurs between SO/sub 2/ and Ca(OH)/sub 2/ in the liquid phase. Solid dissolution in the liquid film is unimportant and solid dissolution and reaction occur in series. A comprehensive model was developed for the constant rate period. The model is based on film theory and treats the atomized slurry droplet as a sphere of discrete sorbent particles with the fluid phase uniformly distributed around the individual sorbent particles. This concept allows prediction of the mass transfer coefficients and the enhancement due to increasing solids concentration as evaporation proceeds. Efficiency predicts using the model were compared with pilot plant data taken at different inlet flue gas temperatures, stoichiometric ratios and slurry flow rates.
Solovyova, N. V.; Lobkovsky, L. I.
2015-09-01
This paper proposes a method of mathematical modelling of ecological risk based on a synthesis of dynamic and probabilistic risk assessment techniques. The probability of assessment of an acceptable probability of an anthropogenic impact to minimize economic costs is proposed. The dependence of an acceptable probability of an anthropogenic impact on the ecological risk is demonstrated with an example calculation. The results of the modelling of the state of a shelf ecosystem based on the dynamic model are used for the calculation as source information. Based on this synthesis, the calculation results bring about the opportunity to balance ecological-economic goals of achieving safe development of the shelf and to satisfy the involuntary necessity to reduce the costs on environmental protection measures, while maintaining the priority of environmental requirements.
SOIL QUALITY ASSESSMENT BASED ON CHEMICAL, ENZYMATIC AND BACTERIOLOGICAL ANALYSIS
Directory of Open Access Journals (Sweden)
Sofia-Paulina BALAURE
2012-01-01
Full Text Available This study highlights the problem of soil pollution as the result of human activities. Soil pollutans may be either chemicals or biological in nature. microbial enzymatic activities are often proposed as indicators of environmental stress. The soil samples were submitted by chemical, microbiological and enzymatic analyses. Chemical analyses were been made for determinating the heavy metals. Heavy metals from the forest soil were represented by Cu, Zn, Mn, Ni, Pb, Cd and Cr. To evaluate the concentration in heavy metals from the filtrate, we used a acetylene-nitrous oxide flame atomic absorption spectrophotometry. Potential dehydrogenase activity, the only indicator of the possible sources of pollution, excluded the presence of either chemical or biological pollution. The number of bacteria involved in the biogeochemical cycle of nitrogen in the analyzed soil indicated a high efficiency regarding the mineralization of the organic residues of plant and animal origin.
DEFF Research Database (Denmark)
Sørensen, John Aasted
2011-01-01
The objectives of Discrete Mathematics (IDISM2) are: The introduction of the mathematics needed for analysis, design and verification of discrete systems, including the application within programming languages for computer systems. Having passed the IDISM2 course, the student will be able to...... accomplish the following: -Understand and apply formal representations in discrete mathematics. -Understand and apply formal representations in problems within discrete mathematics. -Understand methods for solving problems in discrete mathematics. -Apply methods for solving problems in discrete mathematics...... natural numbers. Apply these concepts to new problems. Division and factorizing: Define a prime number and apply Euclid´s algorithm for factorizing an integer. Regular languages: Define a language from the elements of a set; define a regular language; form strings from a regular language; construct...
DEFF Research Database (Denmark)
Misfeldt, Morten; Zacho, Lis
2016-01-01
In this article, we address how the design of educational scenarios can support teachers’ adoption of both technology and open-ended projects indorsing creativity and innovation. We do that by describing how groups of teachers develop digital learning environments supporting using a combination of...... development and testing through qualitative means, aiming to describe the teachers’ appropriation of (1) GeoGebra as a tool for doing and teaching mathematics, and (2) game as a metaphor supporting open-ended projects addressing creativity and innovation in the classroom. The data from the project suggest...... that the notion of “game” can support collaborative scenario design is a viable way of introducing technology and open-ended projects to primary school teachers....
Complex networks and SOA: Mathematical modelling of granularity based web service compositions
Indian Academy of Sciences (India)
S Chatla; S Kadam; D Kolluru; S Sinha; A Viswandhuni; A Vaidya
2011-08-01
Service Oriented Architecture (SOA) can be deﬁned as a way of deﬁning and implementing enterprise applications that deals with the intercommunication of loosely coupled, coarse grained (business level), reusable artifacts (services). In this paper, we attempt to mathematically model the preliminary steps in the larger problem of providing an optimal architecture. The problem is treated as a complex network, particularly a process-task-network. We employ statistical and graph-theoretic methods namely, Jaccard’s distance analysis, Multiple Correspondence method and the Minimum Spanning Tree method, to ﬁnd appropriate clusters. These methods are used to cluster tasks across business processes to propose services. Additional properties and features of these clusters are discussed. We propose a leverage factor which demonstrates the importance of a task within the service and its impact on service composition.
Jung-Woon Yoo, John
2016-06-01
Since customer preferences change rapidly, there is a need for design processes with shorter product development cycles. Modularization plays a key role in achieving mass customization, which is crucial in today's competitive global market environments. Standardized interfaces among modularized parts have facilitated computational product design. To incorporate product size and weight constraints during computational design procedures, a mixed integer programming formulation is presented in this article. Product size and weight are two of the most important design parameters, as evidenced by recent smart-phone products. This article focuses on the integration of geometric, weight and interface constraints into the proposed mathematical formulation. The formulation generates the optimal selection of components for a target product, which satisfies geometric, weight and interface constraints. The formulation is verified through a case study and experiments are performed to demonstrate the performance of the formulation.
A QFD-Based Mathematical Model for New Product Development Considering the Target Market Segment
Directory of Open Access Journals (Sweden)
Liang-Hsuan Chen
2014-01-01
Full Text Available Responding to customer needs is important for business success. Quality function deployment provides systematic procedures for converting customer needs into technical requirements to ensure maximum customer satisfaction. The existing literature mainly focuses on the achievement of maximum customer satisfaction under a budgetary limit via mathematical models. The market goal of the new product for the target market segment is usually ignored. In this study, the proposed approach thus considers the target customer satisfaction degree for the target market segment in the model by formulating the overall customer satisfaction as a function of the quality level. In addition, the proposed approach emphasizes the cost-effectiveness concept in the design stage via the achievement of the target customer satisfaction degree using the minimal total cost. A numerical example is used to demonstrate the applicability of the proposed approach and its characteristics are discussed.
Social Justice Lessons and Mathematics
Johnson, Jason D.
2011-01-01
Assigning activities based on current or past events allows students to explore mathematics in a social context. Using social justice events in the mathematics classroom is a way for teachers to provide contextual problems that will reach all students and promote equity. Learning mathematics in an environment in which social issues are explored…
Pappas, Theoni
1997-01-01
In this highly readable volume of vignettes of mathematical scandals and gossip, Theoni Pappas assembles 29 fascinating stories of intrigue and the bizarre ? in short, the human background of the history of mathematics. Might a haberdasher have changed Einstein's life? Why was the first woman mathematician murdered? How come there's no Nobel Prize in mathematics?Mathematics is principally about numbers, equations, and solutions, all of them precise and timeless. But, behind this arcane matter lies the sometimes sordid world of real people, whose rivalries and deceptions
Stroud, K A
2013-01-01
A groundbreaking and comprehensive reference that's been a bestseller since it first debuted in 1970, the new seventh edition of Engineering Mathematics has been thoroughly revised and expanded. Providing a broad mathematical survey, this innovative volume covers a full range of topics from the very basic to the advanced. Whether you're an engineer looking for a useful on-the-job reference or want to improve your mathematical skills, or you are a student who needs an in-depth self-study guide, Engineering Mathematics is sure to come in handy time and time again.
Jothi, A Lenin
2009-01-01
Financial services, particularly banking and insurance services is the prominent sector for the development of a nation. After the liberalisation of financial sector in India, the scope of getting career opportunities has been widened. It is heartening to note that various universities in India have introduced professional courses on banking and insurance. A new field of applied mathematics has come into prominence under the name of Financial Mathematics. Financial mathematics has attained much importance in the recent years because of the role played by mathematical concepts in decision - m
Mathematics of aperiodic order
Lenz, Daniel; Savinien, Jean
2015-01-01
What is order that is not based on simple repetition, that is, periodicity? How must atoms be arranged in a material so that it diffracts like a quasicrystal? How can we describe aperiodically ordered systems mathematically? Originally triggered by the – later Nobel prize-winning – discovery of quasicrystals, the investigation of aperiodic order has since become a well-established and rapidly evolving field of mathematical research with close ties to a surprising variety of branches of mathematics and physics. This book offers an overview of the state of the art in the field of aperiodic order, presented in carefully selected authoritative surveys. It is intended for non-experts with a general background in mathematics, theoretical physics or computer science, and offers a highly accessible source of first-hand information for all those interested in this rich and exciting field. Topics covered include the mathematical theory of diffraction, the dynamical systems of tilings or Delone sets, their cohomolog...
A paradigm-based evolution of chemical engineering
Institute of Scientific and Technical Information of China (English)
Alexandru Woinaroschy
2016-01-01
A short presentation of chemical engineering evolution, as guided by its paradigms, is exposed. The first paradigm–unit operations–has emerged as a necessity of systematization due to the explosion of chemical industrial applica-tions at the end of 19th century. The birth in the late 1950s of the second paradigm–transport phenomena–was the consequence of the need for a deep, scientific knowledge of the phenomena that explain what happens inside of unit operations. In the second part of 20th century, the importance of chemical product properties and qualities has become essential y in the market fights. Accordingly, it was required with additional and even new fundamen-tal approaches, and product engineering was recognized as the third paradigm. Nowadays chemical industry, as a huge materials and energy consumer, and with a strong ecological impact, couldn't remain outside of sustainability requirements. The basics of the fourth paradigm–sustainable chemical engineering–are now formulated.
Directory of Open Access Journals (Sweden)
Viktor Freiman
2011-12-01
Full Text Available Many educational systems consider using one-to-one access to the laptop as a way to improve teaching and learning. A two-year action research project on the use of laptop computers by New Brunswick (Canada grade 7 and 8 Francophone students aimed to better understand the impact of laptops on learning. Two problem-based learning (PBL interdisciplinary scenarios (math, science, language arts were implemented in eight experimental classes to measure and document students’ actual learning process, particularly in terms of their ability to scientifically investigate authentic problems, to reason mathematically, and to communicate. On-site observations, video-recording, journals, samples of students’ work, and interviews were used to collect qualitative data. Based on our findings, we argue that laptops in and of themselves may not automatically lead to better results on standardized tests, but rather create opportunities to enrich learning with more open-ended, constructive, collaborative, reflective, and cognitively complex learning tasks.
Biodistribution of radiopharmaceuticals - mathematic models
International Nuclear Information System (INIS)
Characteristic biodistributions of radiopharmaceuticals were investigated by means of mathematical pharmacokinetics. Beside linear concentration dependent transport processes the existence of chemical equilibria in corresponding compartments producing chemically different transport and permeating species were included. The derived relations have been demonstrated by mathematical organ models comprising the renal excretion, the distribution of an osteotropic radiopharmaceutical between the skelet and the tumour compartment as well as a kidney model. (author)
Mathematical Thinking and Creativity through Mathematical Problem Posing and Solving
Directory of Open Access Journals (Sweden)
María F. Ayllón
2016-04-01
Full Text Available This work shows the relationship between the development of mathematical thinking and creativity with mathematical problem posing and solving. Creativity and mathematics are disciplines that do not usually appear together. Both concepts constitute complex processes sharing elements, such as fluency (number of ideas, flexibility (range of ideas, novelty (unique idea and elaboration (idea development. These factors contribute, among others, to the fact that schoolchildren are competent in mathematics. The problem solving and posing are a very powerful evaluation tool that shows the mathematical reasoning and creative level of a person. Creativity is part of the mathematics education and is a necessary ingredient to perform mathematical assignments. This contribution presents some important research works about problem posing and solving related to the development of mathematical knowledge and creativity. To that end, it is based on various beliefs reflected in the literature with respect to notions of creativity, problem solving and posing.
Experimental Mathematics and Mathematical Physics
Energy Technology Data Exchange (ETDEWEB)
Bailey, David H.; Borwein, Jonathan M.; Broadhurst, David; Zudilin, Wadim
2009-06-26
One of the most effective techniques of experimental mathematics is to compute mathematical entities such as integrals, series or limits to high precision, then attempt to recognize the resulting numerical values. Recently these techniques have been applied with great success to problems in mathematical physics. Notable among these applications are the identification of some key multi-dimensional integrals that arise in Ising theory, quantum field theory and in magnetic spin theory.
My contribution to broadening the base of chemical engineering.
Sargent, Roger W H
2011-01-01
This paper is a short account, from a personal viewpoint, of the various contributions I have made to expand the academic basis of chemical engineering from its origin in the unifying concept of unit operations, focussed on process design, to encompassing all the professional activities of industrial chemical engineers. This includes all aspects of planning and scheduling the operations as well as designing and controlling the process plant. The span of my career also happens to include the birth of the age of computing, with all the consequential implications. PMID:22432607
Directory of Open Access Journals (Sweden)
Annabelle Ballesta
2011-09-01
Full Text Available Circadian timing largely modifies efficacy and toxicity of many anticancer drugs. Recent findings suggest that optimal circadian delivery patterns depend on the patient genetic background. We present here a combined experimental and mathematical approach for the design of chronomodulated administration schedules tailored to the patient molecular profile. As a proof of concept we optimized exposure of Caco-2 colon cancer cells to irinotecan (CPT11, a cytotoxic drug approved for the treatment of colorectal cancer. CPT11 was bioactivated into SN38 and its efflux was mediated by ATP-Binding-Cassette (ABC transporters in Caco-2 cells. After cell synchronization with a serum shock defining Circadian Time (CT 0, circadian rhythms with a period of 26 h 50 (SD 63 min were observed in the mRNA expression of clock genes REV-ERBα, PER2, BMAL1, the drug target topoisomerase 1 (TOP1, the activation enzyme carboxylesterase 2 (CES2, the deactivation enzyme UDP-glucuronosyltransferase 1, polypeptide A1 (UGT1A1, and efflux transporters ABCB1, ABCC1, ABCC2 and ABCG2. DNA-bound TOP1 protein amount in presence of CPT11, a marker of the drug PD, also displayed circadian variations. A mathematical model of CPT11 molecular pharmacokinetics-pharmacodynamics (PK-PD was designed and fitted to experimental data. It predicted that CPT11 bioactivation was the main determinant of CPT11 PD circadian rhythm. We then adopted the therapeutics strategy of maximizing efficacy in non-synchronized cells, considered as cancer cells, under a constraint of maximum toxicity in synchronized cells, representing healthy ones. We considered exposure schemes in the form of an initial concentration of CPT11 given at a particular CT, over a duration ranging from 1 to 27 h. For any dose of CPT11, optimal exposure durations varied from 3h40 to 7h10. Optimal schemes started between CT2h10 and CT2h30, a time interval corresponding to 1h30 to 1h50 before the nadir of CPT11 bioactivation rhythm in
International Nuclear Information System (INIS)
The X-ray free-electron laser XFEL that is being planned at the DESY research center in cooperation with European partners will produce high-intensity ultra-short Xray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. SIMCON (SIMulator and CONtroller) is the project of the fast, low latency digital controller dedicated for LLRF system in VUV FEL experiment based on modern FPGA chips It is being developed by ELHEP group in Institute of Electronic Systems at Warsaw University of Technology. The main purpose of the project is to create a controller for stabilizing the vector sum of fields in cavities of one cryomodule in the experiment. The device can be also used as the simulator of the cavity and testbench for other devices. Flexibility and computation power of this device allow implementation of fast mathematical algorithms. This paper describes the concept, implementation and tests of universal mathematical library for FPGA algorithm implementation. It consists of many useful components such as IQ demodulator, division block, library for complex and floating point operations, etc. It is able to speed up implementation time of many complicated algorithms. Library have already been tested using real accelerator signals and the performance achieved is satisfactory. (Orig.)
Directory of Open Access Journals (Sweden)
Youxin Luo
2013-01-01
Full Text Available The pose of the moving platform in parallel robots is possible thanks to the strong coupling, but it consequently is very difficult to obtain its forward displacement. Different methods establishing forward displacement can obtain different numbers of variables and different solving speeds with nonlinear equations. The nonlinear equations with nine variables for forward displacement in the general 6‐6 type parallel mechanism were created using the rotation transformation matrix R , translation vector P and the constraint conditions of the rod length. Given the problems of there being only one solution and sometimes no convergence when solving nonlinear equations with the Newton method and the quasi‐Newton method, the Euler equation for free rotation in a rigid body was applied to a chaotic system by using chaos anti‐control and chaotic sequences were produced. Combining the characteristics of the chaotic sequence with the mathematical programming method, a new mathematical programming method was put forward, which was based on chaos anti‐control with the aim of solving all real solutions of nonlinear equations for forward displacement in the general 6‐6 type parallel mechanism. The numerical example shows that the new method has some positive characteristics such as that it runs in the initial value range, it has fast convergence, it can find all the possible real solutions that be found out and it proves the correctness and validity of this method when compared with other methods.
Institute of Scientific and Technical Information of China (English)
曹春艳; 张定强
2012-01-01
Based on dimensions of mathematics test scores and mathematics test anxiety to discuss factors of affecting mathematics adversity quotient will benefit to reveal the internal mechanisms of mathematics learning and explore large area strategy of improving mathematics levels.165 students were conducted by self-edited mathematics adversity quotient questionnaire,mathematics test anxiety questionnaire and mid-term test scores.Results show that：there is a significant positive correlation between mathematics adversity quotient and mathematics test scores（P 0.01）,the latter has some influence on the former;there is a significant negative correlation between mathematics adversity quotient and mathematics test anxiety（P 0.01）, the relief of the latter will help the improvement of the former.%基于数学考试成绩和数学考试焦虑的维度探讨影响数学逆商的因素有利于揭示初中生数学学习过程中的真实状态,探寻大面积提高学生数学学习水平的方略.采用自编的数学逆商调查量表、数学考试焦虑量表以及学生期中数学考试成绩等对初中生进行调查.发现：初中生的数学逆商和数学考试成绩呈显著正相关（P〈0.01）,数学考试成绩对数学逆商具有显著影响作用.初中生的数学逆商和数学考试焦虑呈显著负相关（P〈0.01）,数学考试焦虑的缓解有利于数学逆商的提升.
Prochazka, Helen
2004-01-01
One section of this "scrapbook" section describes Pythagoras' belief in the connections between music and mathematics -- that everything in the universe was a series of harmonies and regulated by music. Another section explains why Phythagoras felt it important for women to be encouraged to learn mathematics. At least 28 women were involved in his…
Thurston, William P.
2005-01-01
This essay, originally published in the Sept 1990 Notices of the AMS, discusses problems of our mathematical education system that often stem from widespread misconceptions by well-meaning people of the process of learning mathematics. The essay also discusses ideas for fixing some of the problems. Most of what I wrote in 1990 remains equally applicable today.
Kleene, Stephen Cole
2002-01-01
Undergraduate students with no prior instruction in mathematical logic will benefit from this multi-part text. Part I offers an elementary but thorough overview of mathematical logic of 1st order. Part II introduces some of the newer ideas and the more profound results of logical research in the 20th century. 1967 edition.
Investigation of the Bose–Einstein condensation based on fractality using fractional mathematics
International Nuclear Information System (INIS)
Although atomic Bose gases are investigated in the dilute gas regime, the physical properties of the Bose–Einstein condensates are affected by interparticle interactions and the fractal nature of the space where the Bose systems are evolving. Theoretical predictions of the traditional Bose–Einstein thermostatistics do not account for the deviations from the experimental results, which are related to internal energy, specific heat, transition temperature, etc. On the other hand, in this study, fractional calculus is introduced where effects of the fractality of space are taken into account. Meanwhile, the order of the fractional derivative α is handled as a measure of the fractality of space. In this content, some improvements which take into account the effects of the fractal nature of the system are made in the standard physical results of the Bose–Einstein condensation phenomena. As an example, for the dilute atomic gas 7Li, the measured transition temperature of Bose–Einstein condensation could be obtained for the value of α ≈ 0.976, and one could predict that the interparticle interactions have a weak attractive nature consistent with experiment (Bradley et al 1995 Phys. Rev. Lett. 75 1687). Thus, a fractional mathematical theory is established in coherence with experimental results of Bose–Einstein condensation
Ping, Qingyun; Abu-Reesh, Ibrahim M; He, Zhen
2016-11-01
Boron removal is an arising issue in desalination plants due to boron's toxicity. As an emerging treatment concept, bioelectrochemical systems (BES) can achieve potentially cost-effective boron removal by taking advantage of cathodic-produced alkali. Prior studies have demonstrated successful removal of boron in microbial desalination cells (MDCs) and microbial fuel cells (MFCs), both of which are representative BES. Herein, mathematical models were developed to further evaluate boron removal by different BES and understand the key operating factors. The models delivered very good prediction of the boron concentration in the MDC integrated with Donnan Dialysis (DD) system with the lowest relative root-mean-square error (RMSE) of 0.00%; the predication of the MFC performance generated the highest RMSE of 18.55%. The model results of salt concentration, solution pH, and current generation were well fitted with experimental data for RMSE values mostly below 10%. The long term simulation of the MDC-DD system suggests that the accumulation of salt in the catholyte/stripping solution could have a positive impact on the removal of boron due to osmosis-driven convection. The current generation in the MDC may have little influence on the boron removal, while in the MFC the current-driven electromigration can contribute up to 40% of boron removal. Osmosis-induced convection transport of boron could be the major driving force for boron removal to a low level 22.2 in order to avoid boron accumulation in the anolyte effluent. PMID:27387806
Institute of Scientific and Technical Information of China (English)
2010-01-01
Fuzzy mathematics comprehensive evaluation method is used to evaluate the geological environment suitability of rural urbanization in Qingdao City,China.A total of 5 first-level evaluation factors are selected,including environmental geological condition,geological resources,engineering geological condition,geological disaster and environmental geological problem,and human engineering activity.And there are 27 second-level evaluation factors,such as topography,land type and vegetation,nature reserve,water source protection area,groundwater quality division,and major engineering project.Qingdao City is divided into four districts of suitable area,relatively suitable area,moderately suitable area and relatively unsuitable area of ecological environment.And their characteristics are introduced.Suggestions for the developing direction of urban construction are put forward.Region of Laoshan District lying to the west of the Shilaoren is suitable to set up high-rise building;west Hongshiya may establish a waste landfill site;Jiaozhou Bay,the downstream of Dagu River,and Jihongtan Reservoir should be built as the key geological environment protection area and water source protection area.And the north Hongdao should be strictly monitored in order to control the expansion of urban construction to Jihongtan Reservoir.Mocheng District and the area north of it,Jiaozhou District and the area east of it are the ideal urban construction development areas in Qingdao City in the future.
A string matching based algorithm for performance evaluation of mathematical expression recognition
Indian Academy of Sciences (India)
P Pavan Kumar; Arun Agarwal; Chakravarthy Bhagvati
2014-02-01
In this paper, we have addressed the problem of automated performance evaluation of Mathematical Expression (ME) recognition. Automated evaluation requires that recognition output and ground truth in some editable format like LaTeX, MathML, etc. have to be matched. But standard forms can have extraneous symbols or tags. For example,
Model Based Monitoring and Control of Chemical and Biochemical Processes
DEFF Research Database (Denmark)
Huusom, Jakob Kjøbsted
This presentation will give an overview of the work performed at the department of Chemical and Biochemical Engineering related to process control. A research vision is formulated and related to a number of active projects at the department. In more detail a project describing model estimation and...
A Polygeneration System Based on Multi-Input Chemical Looping Combustion
Xiaosong Zhang; Sheng Li; Hongguang Jin
2014-01-01
This paper proposes a polygeneration system based on a multi-input chemical looping combustion system, which generates methanol and electricity, through the use of natural gas and coal. In this system, the chemical looping hydrogen (CLH) production system and the coal-based methanol production system are integrated. A high quality fuel, natural gas, is used to improve the conversion ratio of coal. The Gibbs energy of the two kinds of fuels is fully used. Benefitting from the chemical looping ...
Chemical Response of CESM/CAM-Chem to MOPITT CO Ensemble-based Chemical Data Assimilation
Gaubert, B.; Arellano, A. F.; Barré, J.; Worden, H. M.; Emmons, L. K.; Tilmes, S.; Buchholz, R. R.; Wiedinmyer, C.; Vitt, F.; Anderson, J. L.; Deeter, M. N.; Edwards, D. P.
2015-12-01
Carbon Monoxide is a key component in tropospheric chemistry. It plays an important role by affecting the oxidative capacity through its reaction with OH and being a precursor of tropospheric ozone. One year of multispectral retrievals of CO partial columns obtained from the MOPITT instrument have been assimilated into the Community Atmosphere Model with Chemistry (CAM-Chem). The assimilation is carried out using an Ensemble Adjustment Kalman Filter algorithm within the Data Assimilation Research Testbed (DART) package. Two assimilation experiments have been performed: 1) assimilation of meteorological observations and 2) joint assimilation of meteorological observations and MOPITT CO. We first evaluate the assimilation performance by investigating skill scores and other statistics for the two experiments, and comparing to independent CO datasets such as surface (WDCGG), aircraft (MOZAIC-IAGOS), and FTS (NDACC). Our results clearly demonstrate an overall improvement for spatio-temporal magnitude and variability in representing CO abundance in CAM-Chem. We then investigate the response of CAM-Chem to changes in CO fields (via CO assimilation) focusing mainly on the oxidative capacity (i.e., OH distribution, methane lifetime) and CO chemical production and loss (i.e., regional to global budget). This is carried out by analyzing the mean 6-hourly forecast adjustments as reflected between the two experiments. We show that changes in CO directly impact OH abundance, with subsequent non-linear responses in CO chemical production (CO from methane and VOCs) and CO loss. This is clearly evident in NOx-limited regions (e.g., Southern Hemisphere, remote sites). Such analysis has direct implications on the consistencies in inverse modeling estimates of CO sources through improved representation of chemical response (including full chemistry) in atmospheric chemistry models and through multi-species constraints.
International Nuclear Information System (INIS)
Highlights: • Moving bed reducer maximizes solids conversion and maintains full fuel conversion. • 850+ Operating hours completed in 25-kWth sub-pilot chemical looping units. • Full solid and gaseous fuel conversion achieved in sub-pilot chemical looping units. • Fully integrated, pressurized 250-kWth pilot SCL unit construction initiated. • Extensive techno-economic analysis performed on CDCL and SCL process configurations. - Abstract: The increasing demands for energy and concern of global warming are intertwined issues of critical importance. With the pressing need for clean, efficient, and cost-effective energy conversion processes, the chemical looping strategy has evolved as a promising alternative to the traditional carbonaceous fuel conversion processes. Chemical looping processes utilize oxygen carrier particles to indirectly convert carbonaceous fuels while capturing CO2 for sequestration and/or utilization. Throughout its development, multiple oxygen carrier compositions and reactor configurations have been studied and demonstrated. The Ohio State University (OSU) chemical looping technologies have received significant attention over the recent years. OSU’s unique moving-bed chemical looping technologies coupled with iron-based oxygen carrier particles capable of sustaining hundreds of redox cycles have the advantage of converting a variety of carbonaceous fuels, such as natural gas, coal and biomass, to electricity, H2, liquid fuels, or any combination thereof with zero to negative net CO2 emissions. Specifically, two chemical looping processes are being developed and studied, the syngas chemical looping (SCL) and the coal direct chemical looping (CDCL) technologies. Over the past 14 years, these processes have developed from a novel concept to successful sub-pilot (25 kWth) demonstrations. With the support of the Advanced Research Projects Agency – Energy (ARPA-E) of the US Department of Energy (USDOE), a 250 kWth high pressure SCL pilot
Amplifying the SERS signal of DNA bases via the chemical resonance
Freeman, Lindsay M.; Pang, Lin; Fainman, Yeshaiahu
2015-03-01
Label-free detection methods of DNA bases using surface-enhanced Raman spectroscopy (SERS) have yet to be successfully utilized due to inconsistent signal readouts. We have identified the primary reason for the discrepancies in the SERS signals of nucleic acids as being caused by the charge-transfer chemical resonance of the base silver system which is dependent on excitation wavelength. Time-dependent density functional theory (TD-DFT) methods to calculate the electronic transitions and resonance Raman spectra of base silver complexes are performed, and the optimal excitation wavelength for the charge-transfer electronic transition is found for each base silver complex. The enhancement caused by the chemical resonance is then experimentally measured for adenine, cytosine, guanine and thymine at multiple excitation wavelengths. The dependence of the Raman intensity on excitation wavelength shows good agreement with the TD-DFT calculations. In order to fully achieve the maximum Raman intensity, both the electromagnetic and chemical resonance must be enhanced by the appropriate wavelength selection. Based on the optimal chemical resonance Raman wavelength, we design a SERS substrate which has an electromagnetic maximum wavelength that matches the chemical resonance wavelength. By aligning both resonances, the highest Raman intensity can be found for each base silver system. We have proven that the variance in DNA bases' Raman intensities are caused by chemical enhancement. By incorporating the chemical resonance and optimizing both the chemical and electromagnetic resonance, we believe a label-free DNA SERS based detection method can be realized.
Dambacher, Jeffrey M; Rothlisberg, Peter C; Loneragan, Neil R
2015-01-01
A major decline in the catch of the banana prawn [shrimp], Penaeus (Fenneropenaeus) merguiensis, occurred over a six-year period in the Weipa region of the northeastern Gulf of Carpentaria, Australia. Three main hypotheses have been developed to explain this decline: (1) prawn recruitment collapsed due to overfishing; (2) recruitment collapsed due to a change in the prawn's environment; and (3) adult banana prawns were still present, but fishers could no longer effectively find or catch them. Qualitative mathematical models were used to link population biology, environmental factors, and fishery dynamics to evaluate the alternative hypotheses. This modeling approach provides the means to rapidly integrate knowledge across disciplines and consider alternative hypotheses about how the structure and function of an ecosystem affects its dynamics. Alternative models were constructed to address the different hypotheses and also to encompass a diversity of opinion about the underlying dynamics of the system. Key findings from these analyses are that: instability in the system can arise when discarded fishery bycatch supports relatively high predation pressure; system stability can be enhanced by management of fishing effort or stock catchability; catch per unit effort is not necessarily a reliable indicator of stock abundance; a change in early-season rainfall should affect all stages in the banana prawn's life cycle; and a reduced catch in the Weipa region can create and reinforce a shift in fishing effort away from Weipa. Results from the models informed an approach to test the hypotheses (i.e., an experimental fishing program), and promoted understanding of the system among researchers, management agencies, and industry. The analytical tools developed in this work to address stages of a prawn life cycle and fishery dynamics are generally applicable to any exploited natural. resource. PMID:26255373
Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling
Energy Technology Data Exchange (ETDEWEB)
Randall S. Seright
2007-09-30
This final technical progress report describes work performed from October 1, 2004, through May 16, 2007, for the project, 'Aperture-Tolerant, Chemical-Based Methods to Reduce Channeling'. We explored the potential of pore-filling gels for reducing excess water production from both fractured and unfractured production wells. Several gel formulations were identified that met the requirements--i.e., providing water residual resistance factors greater than 2,000 and ultimate oil residual resistance factors (F{sub rro}) of 2 or less. Significant oil throughput was required to achieve low F{sub rro} values, suggesting that gelant penetration into porous rock must be small (a few feet or less) for existing pore-filling gels to provide effective disproportionate permeability reduction. Compared with adsorbed polymers and weak gels, strong pore-filling gels can provide greater reliability and behavior that is insensitive to the initial rock permeability. Guidance is provided on where relative-permeability-modification/disproportionate-permeability-reduction treatments can be successfully applied for use in either oil or gas production wells. When properly designed and executed, these treatments can be successfully applied to a limited range of oilfield excessive-water-production problems. We examined whether gel rheology can explain behavior during extrusion through fractures. The rheology behavior of the gels tested showed a strong parallel to the results obtained from previous gel extrusion experiments. However, for a given aperture (fracture width or plate-plate separation), the pressure gradients measured during the gel extrusion experiments were much higher than anticipated from rheology measurements. Extensive experiments established that wall slip and first normal stress difference were not responsible for the pressure gradient discrepancy. To explain the discrepancy, we noted that the aperture for gel flow (for mobile gel wormholing through concentrated
Higher engineering mathematics
John Bird
2014-01-01
A practical introduction to the core mathematics principles required at higher engineering levelJohn Bird's approach to mathematics, based on numerous worked examples and interactive problems, is ideal for vocational students that require an advanced textbook.Theory is kept to a minimum, with the emphasis firmly placed on problem-solving skills, making this a thoroughly practical introduction to the advanced mathematics engineering that students need to master. The extensive and thorough topic coverage makes this an ideal text for upper level vocational courses. Now in
Transition to abstract mathematics learning mathematical thinking and writing
Maddox, Randall
2008-01-01
Constructing concise and correct proofs is one of the most challenging aspects of learning to work with advanced mathematics. Meeting this challenge is a defining moment for those considering a career in mathematics or related fields. Mathematical Thinking and Writing teaches readers to construct proofs and communicate with the precision necessary for working with abstraction. It is based on two premises: composing clear and accurate mathematical arguments is critical in abstract mathematics, and that this skill requires development and support. Abstraction is the destination, not the starting
Calculations of NMR chemical shifts with APW-based methods
Laskowski, Robert; Blaha, Peter
2012-01-01
We present a full potential, all electron augmented plane wave (APW) implementation of first-principles calculations of NMR chemical shifts. In order to obtain the induced current we follow a perturbation approach [Pickard and Mauri, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.63.245101 63, 245101 (2001)] and extended the common APW + local orbital (LO) basis by several LOs at higher energies. The calculated all-electron current is represented in traditional APW manner as Fourier series in the interstitial region and with a spherical harmonics representation inside the nonoverlapping atomic spheres. The current is integrated using a “pseudocharge” technique. The implementation is validated by comparison of the computed chemical shifts with some “exact” results for spherical atoms and for a set of solids and molecules with available published data.
Process Design and Evaluation for Chemicals Based on Renewable Resources
DEFF Research Database (Denmark)
Fu, Wenjing
One of the key steps in process design is choosing between alternative technologies, especially for processes producing bulk and commodity chemicals. Recently, driven by the increasing oil prices and diminishing reserves, the production of bulk and commodity chemicals from renewable feedstocks has...... well as to match different catalyst conditions. These kinds of problems are crucial, especially at the early stages of process development, when information is limited. This thesis describes a methodological framework for dealing with the challenges and giving direction to research in the process...... process design of the synthesis 2,5-furandicarboxylic acid (FDA) from glucose. By using the selected case study, the complexity and challenges for the process engineer to choose between different alternative routes and technologies as well as to combine two different kinds of catalysis (enzymatic...
Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.
2015-04-01
This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the
International Nuclear Information System (INIS)
An idealized mathematical model for carcinogenesis is proposed, based on age-time patterns of excess solid cancer risk seen in the Radiation Effects Research Foundation data on A-bomb survivors. The primary component is similar to the Armitage-Doll multistage model, with the interpretation that the events in that model are somatic mutations. The manner of extending this model to incorporate effects of a specific carcinogen, here an acute irradiation, is novel in the sense that the irradiation can cause any one of the mutations in the multi-event process. The motivation for this formulation is the observation that the excess solid cancer rate associated with radiation exposure appears largely to depend only on attained age, rather than on age at exposure and time since exposure. The model is fitted to the A-bomb survivor data on a class of cancers consisting of the major non-sex-specific types. (author)
International Nuclear Information System (INIS)
The present research develops new statistical methodology, mathematical models, and data bases of relevance to the assessment of health impacts of energy technologies, and uses these to identify, quantify, and pedict adverse health effects of energy related pollutants. Efforts are in five related areas including: (1) evaluation and development of statistical procedures for the analysis of death rate data, disease incidence data, and large scale data sets; (2) development of dose response and demographic models useful in the prediction of the health effects of energy technologies; (3) application of our method and models to analyses of the health risks of energy production; (4) a reanalysis of the Tri-State leukemia survey data, focusing on the relationship between myelogenous leukemia risk and diagnostic x-ray exposure; and (5) investigation of human birth weights as a possible early warning system for the effects of environmental pollution
Design of LTCC-based Ceramic Structure for Chemical Microreactor
D. Belavic; Hrovat, M.; G. Dolanc; Santo Zarnik, M.; Holc, J.; Makarovic, K.
2012-01-01
The design of ceramic chemical microreactor for the production of hydrogen needed in portable polymer-electrolyte membrane (PEM) fuel cells is presented. The microreactor was developed for the steam reforming of liquid fuels with water into hydrogen. The complex three-dimensional ceramic structure of the microreactor includes evaporator(s), mixer(s), reformer and combustor. Low-temperature co-fired ceramic (LTCC) technology was used to fabricate the ceramic structures with buried cavities and...
Czech Academy of Sciences Publication Activity Database
Prasanna, M. D.; Vondrášek, Jiří; Wlodawer, A.; Rodriguez, H.; Bhat, T. N.
2006-01-01
Roč. 63, č. 4 (2006), s. 907-917. ISSN 0887-3585 Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV * AIDS * drug discovery * chemical data-tree Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.730, year: 2006
Logan, J David
2013-01-01
Praise for the Third Edition"Future mathematicians, scientists, and engineers should find the book to be an excellent introductory text for coursework or self-study as well as worth its shelf space for reference." -MAA Reviews Applied Mathematics, Fourth Edition is a thoroughly updated and revised edition on the applications of modeling and analyzing natural, social, and technological processes. The book covers a wide range of key topics in mathematical methods and modeling and highlights the connections between mathematics and the applied and nat
Virdi, Surinder
2006-01-01
Taking a starting point below that of GCSE level, by assuming no prior mathematical knowledge, Surinder Virdi and Roy Baker take the reader step by step through the mathematical requirements for Level 2 and 3 Building and Construction courses.Unlike the majority of basic level maths texts available, this book focuses exclusively on mathematics as it is applied in actual construction practice. As such, topics specific to the construction industry are presented, as well as essential areas for Level 2 craft NVQs - for example, costing calculations, labor costs, cost of materials and setting out o
Handley, Bill
2012-01-01
This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud
Mathematical statistics with applications
Ramachandran, KM
2009-01-01
Mathematical Statistics with Applications provides a calculus-based theoretical introduction to mathematical statistics while emphasizing interdisciplinary applications as well as exposure to modern statistical computational and simulation concepts that are not covered in other textbooks. Includes the Jackknife, Bootstrap methods, the EM algorithms and Markov chain Monte Carlo methods. Prior probability or statistics knowledge is not required.* Step-by-step procedure to solve real problems, making the topic more accessible* Exercises blend theory and modern applications*
Resilience and vulnerability to a natural hazard: A mathematical framework based on viability theory
Rougé, Charles; Mathias, Jean-Denis; Deffuant, Guillaume
2013-04-01
This deals with the response of a coupled human and natural system (CHANS) to a natural hazard by using the concepts of resilience and vulnerability within the mathematical framework of viability theory. This theory applies to time-evolving systems such as CHANS and assumes that their desirable properties can be defined as a subset of their state space. Policies can also apply to influence the dynamics of such systems: viability theory aims at finding the policies which keep the properties of a controlled dynamical system for so long as no disturbance hits it. The states of the system such that the properties are guaranteed constitute what is called the viability kernel. This viability framework has been extended to describe the response to a perturbation such as a natural hazard. Resilience describes the capacity of the CHANS to recover by getting back in the viability kernel, where its properties are guaranteed until the onset of the next major event. Defined for a given controlled trajectory that the system may take after the event ends, resilience is (a) whether the system comes back to the viability kernel within a given budget such as a time constraint, but also (b) a decreasing function of vulnerability. Computed for a given trajectory as well, vulnerability is a measure of the consequence of violating a property. We propose a family of functions from which cost functions and other vulnerability indicators can be derived for a certain trajectory. There can be several vulnerability functions, representing for instance social, economic or ecological vulnerability, and each representing the violation of an associated property, but these functions need to be ultimately aggregated as a single indicator. Computing the resilience and vulnerability of a trajectory enables the viability framework to describe the response of both deterministic and stochastic systems to hazards. In the deterministic case, there is only one response trajectory for a given action policy
Forrest, Jay; Bazylewski, Paul; Bauer, Robert; Hong, Seongjin; Kim, Chang Yong; Giesy, John P; Khim, Jong Seong; Chang, Gap Soo
2014-01-01
Here, we present a novel model to predict the toxicity and bioavailability of polychlorinated biphenyls (PCBs) as model compounds based on a first principles approach targeting basic electronic characteristics. The predictive model is based on an initio density functional theory. The model suggests HOMO-LUMO energy gap as the overarching indicator of PCBs toxicity, which was shown to be the primary factor predicting toxicity, but not the only factor. The model clearly explains why chlorinatio...
Rosa, Milton; Orey, Daniel Clark
2015-01-01
In an ethnomathematics-based program there exists the need for teachers to identify pedagogical actions in the form of teaching-learning practices. In this theoretical paper we outline a curriculum proposal based on D'Ambrosio's "Trivium," composed of "literacy," "matheracy," and "technoracy." The Trivium…
Nutti, Ylva Jannok
2013-01-01
The goal of Indigenous education is that it should be approached on the basis of the Indigenous language and culture; this is also the case with Sami education. The Sami School Board has stated that all teaching in Sami schools should be culturally based, despite the fact that Sami culture-based teaching is not specifically defined. Therefore,…
Raman-spectroscopy-based chemical contaminant detection in milk powder
Dhakal, Sagar; Chao, Kuanglin; Qin, Jianwei; Kim, Moon S.
2015-05-01
Addition of edible and inedible chemical contaminants in food powders for purposes of economic benefit has become a recurring trend. In recent years, severe health issues have been reported due to consumption of food powders contaminated with chemical substances. This study examines the effect of spatial resolution used during spectral collection to select the optimal spatial resolution for detecting melamine in milk powder. Sample depth of 2mm, laser intensity of 200mw, and exposure time of 0.1s were previously determined as optimal experimental parameters for Raman imaging. Spatial resolution of 0.25mm was determined as the optimal resolution for acquiring spectral signal of melamine particles from a milk-melamine mixture sample. Using the optimal resolution of 0.25mm, sample depth of 2mm and laser intensity of 200mw obtained from previous study, spectral signal from 5 different concentration of milk-melamine mixture (1%, 0.5%, 0.1%, 0.05%, and 0.025%) were acquired to study the relationship between number of detected melamine pixels and corresponding sample concentration. The result shows that melamine concentration has a linear relation with detected number of melamine pixels with correlation coefficient of 0.99. It can be concluded that the quantitative analysis of powder mixture is dependent on many factors including physical characteristics of mixture, experimental parameters, and sample depth. The results obtained in this study are promising. We plan to apply the result obtained from this study to develop quantitative detection model for rapid screening of melamine in milk powder. This methodology can also be used for detection of other chemical contaminants in milk powders.
A MEMS Based Hybrid Preconcentrator/Chemiresistor Chemical Sensor
Energy Technology Data Exchange (ETDEWEB)
HUGHES,ROBERT C.; PATEL,SANJAY V.; MANGINELL,RONALD P.
2000-06-12
A hybrid of a microfabricated planar preconcentrator and a four element chemiresistor array chip has been fabricated and the performance as a chemical sensor system has been demonstrated. The close proximity of the chemiresistor sensor to the preconcentrator absorbent layer allows for fast transfer of the preconcentrated molecules during the heating and resorption step. The hybrid can be used in a conventional flow sampling system for detection of low concentrations of analyte molecules or in a pumpless/valveless mode with a grooved lid to confine the desorption plume from the preconcentrator during heating.
Sneyd, James
2009-01-01
There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...
Institute of Scientific and Technical Information of China (English)
无
2004-01-01
Puzzles of purely logical nature are distinguished from most mathematical puzzles,in that thought rather than memory, that is,native mental ingenuity rather than a store of acquired information, is the key to their solution.
Viader Canals, Pelegrí
2013-01-01
Apunts de l'assignatura Mathematics III del Grau en International Business Economics del curs 2012-2013. Conté : Diagonalization, Difference Equations, Differential Equations, Lagrange-Kuhn-Tucker, Second order Difference Equations.
2016-01-01
This book provides a thorough introduction to the challenge of applying mathematics in real-world scenarios. Modelling tasks rarely involve well-defined categories, and they often require multidisciplinary input from mathematics, physics, computer sciences, or engineering. In keeping with this spirit of modelling, the book includes a wealth of cross-references between the chapters and frequently points to the real-world context. The book combines classical approaches to modelling with novel areas such as soft computing methods, inverse problems, and model uncertainty. Attention is also paid to the interaction between models, data and the use of mathematical software. The reader will find a broad selection of theoretical tools for practicing industrial mathematics, including the analysis of continuum models, probabilistic and discrete phenomena, and asymptotic and sensitivity analysis.
Energy Technology Data Exchange (ETDEWEB)
Magdzinski, L. (ed.)
2007-07-01
This workshop was held to establish commercial processes for the generation of sustainable chemical feedstock from pulp mills. The workshop was attended by over 60 participants from the pulp and paper industry as well as members of the chemical, forestry, and industrial biotechnology industries. Representatives from governments and academic institutions also attended. Links were established between the Ontario forest sector and the Ontario chemical and and polymer sectors. The workshop presented a range of topics for discussion among participants, including issues related to the development of industrial chemicals from pulp mills and methods of sustainably extracting chemicals from hemicellulose. Issues related to the development of bioplastics from pulp production were discussed as well as new developments in wood-derived pharmaceuticals and nutraceuticals. Ontario forestry resources were reviewed, and a Paprican biorefinery agenda was presented. Current pulp mill bio-based chemicals were discussed, and sustainable feedstocks for the production of chemicals were identified. Industrial bioconversion processes were also outlined.
DEFF Research Database (Denmark)
Sørensen, John Aasted
2010-01-01
The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Spring 2010 Ectent: 5 ects Class size: 18...
DEFF Research Database (Denmark)
Sørensen, John Aasted
2010-01-01
The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15......The introduction of the mathematics needed for analysis, design and verification of discrete systems, including applications within programming languages for computer systems. Course sessions and project work. Semester: Autumn 2010 Ectent: 5 ects Class size: 15...
Berman, Elizabeth
1979-01-01
Mathematics Revealed focuses on the principles, processes, operations, and exercises in mathematics.The book first offers information on whole numbers, fractions, and decimals and percents. Discussions focus on measuring length, percent, decimals, numbers as products, addition and subtraction of fractions, mixed numbers and ratios, division of fractions, addition, subtraction, multiplication, and division. The text then examines positive and negative numbers and powers and computation. Topics include division and averages, multiplication, ratios, and measurements, scientific notation and estim
Modeling and computational simulation of adsorption based chemical heat pumps
International Nuclear Information System (INIS)
In this study a methodology is developed for the design of a packed bed reactor to be used in a Chemical Heat Pump (CHP). Adsorption and desorption of ethanol on active carbon packing in the reactor are investigated. Depending on the cycle, i.e. adsorption or desorption, cooling or heating of the reactor material is modeled through transient energy equation. The parameters associated with the vapor-carbon adsorption kinetics are experimentally determined. Then spatial distribution of temperature and adsorbed vapor amount are obtained with respect to time in adsorption–desorption cycles. These profiles are used to predict heating or cooling powers and COP for different adsorbent bed geometries and adsorption/desorption cycle times. Strong effect of heat transfer resistance of the packing, hence reactor size, on the system performance is observed. - Highlights: ► Performance of a chemical pump reactor is investigated theoretically. ► Ethanol adsorption/desorption on active carbon packing is modeled and simulated. ► Adsorption/desorption kinetics and equilibrium relations are found experimentally.
Sayantan Nath; Sonali Agarwal; G.N. Pandey
2015-01-01
In this paper, integration between multiple functions of image processing and its statistical parameters for intelligent alarming series based fire detection system is presented. The proper inter-connectivity mapping between processing elements of imagery based on classification factor for temperature monitoring and multilevel intelligent alarm sequence is introduced by abstractive canonical approach. The flow of image processing components between core implementation of intelligent alarming ...
Inquiry based learning in science education and mathematics for developing bilinguals
Directory of Open Access Journals (Sweden)
Nataliya H. Pavlova
2015-09-01
Full Text Available This article studies the problem of teaching bilingual children. A definition of “developing bilingual” is proposed. The article presents an example of the application of inquiry based learning through which students develop not only math skills but also lexical capabilities. This study offers levels of differentiation in different groups of students. The paper determines advantages and disadvantages of the use of Inquiry Based Learning in developing bilingual groups.
Liu, Yewei; YIN Ting; Feng, Yuanbo; Cona, Marlein Miranda; Huang, Gang; Liu, Jianjun; Song, Shaoli; Jiang, Yansheng; Xia, Qian; Swinnen, Johannes V; Bormans, Guy; Himmelreich, Uwe; Oyen, Raymond; Ni, Yicheng
2015-01-01
Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-spe...
Christensen, Anders S
2015-01-01
This report covers the development of a new, fast method for calculating the backbone amide proton chemical shifts in proteins. Through quantum chemical calculations, structure-based forudsiglese the chemical shift for amidprotonen in protein has been parameterized. The parameters are then implemented in a computer program called Padawan. The program has since been implemented in protein folding program Phaistos, wherein the method andvendes to de novo folding of the protein structures and to refine the existing protein structures.
Carbon Nanostructure-Based Field-Effect Transistors for Label-Free Chemical/Biological Sensors
PingAn Hu; Jia Zhang; Le Li; Zhenlong Wang; William O’Neill; Pedro Estrela
2010-01-01
Over the past decade, electrical detection of chemical and biological species using novel nanostructure-based devices has attracted significant attention for chemical, genomics, biomedical diagnostics, and drug discovery applications. The use of nanostructured devices in chemical/biological sensors in place of conventional sensing technologies has advantages of high sensitivity, low decreased energy consumption and potentially highly miniaturized integration. Owing to their particular structu...
Directory of Open Access Journals (Sweden)
Liu Cong
2011-12-01
Full Text Available Abstract Background Elucidating the effects of drugs on solid tumours is a highly challenging multi-level problem, since this involves many complexities associated with transport and cellular response, which in turn is characterized by highly non-linear chemical signal transduction. Appropriate systems frameworks are needed to seriously address the sources of these complexities, especially from the cellular side. Results We develop a skeletal modelling framework incorporating interstitial drug transport, intracellular signal processing and cell population descriptions. The descriptions aim to appropriately capture the nature of information flow. The model is deliberately formulated to start with simple intracellular descriptions so that additional features can be incorporated in a modular fashion. Two kinds of intracellular signalling modules which describe the drug effect were considered, one a monostable switch and the other a bistable switch. Analysis of our model revealed how different drug stimuli can lead to cell killing in the tumour. Interestingly both modules considered exhibited similar trends. The effects of important parameters were also studied. Conclusions We have created a predictive systems platform integrating drug transport and cellular response which can be systematically augmented to include additional layers of cellular complexity. Our results indicate that intracellular signalling models which are qualitatively different can give rise to similar behaviour to simple (and typical stimuli, and that validating intracellular descriptions must be performed with care by considering a variety of drug stimuli.
Design of LTCC-based Ceramic Structure for Chemical Microreactor
Directory of Open Access Journals (Sweden)
D. Belavic
2012-04-01
Full Text Available The design of ceramic chemical microreactor for the production of hydrogen needed in portable polymer-electrolyte membrane (PEM fuel cells is presented. The microreactor was developed for the steam reforming of liquid fuels with water into hydrogen. The complex three-dimensional ceramic structure of the microreactor includes evaporator(s, mixer(s, reformer and combustor. Low-temperature co-fired ceramic (LTCC technology was used to fabricate the ceramic structures with buried cavities and channels, and thick-film technology was used to make electrical heaters, temperature sensors and pressure sensors. The final 3D ceramic structure consists of 45 LTCC tapes. The dimensions of the structure are 75 × 41 × 9 mm3 and the weight is about 73 g.
SDG-based Model Validation in Chemical Process Simulation
Institute of Scientific and Technical Information of China (English)
张贝克; 许欣; 马昕; 吴重光
2013-01-01
Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a soft-ware environment that can automate the validation activity. This paper is concentrated on the pretreatment of the model validation. We use the validation scenarios and standard sequences generated by well-established SDG model to validate the trends fitted from the simulation model. The results are helpful to find potential problems, as-sess possible bugs in the simulation model and solve the problem effectively. A case study on a simulation model of boiler is presented to demonstrate the effectiveness of this method.
Roth McDuffie, Amy; Foote, Mary Q.; Bolson, Catherine; Turner, Erin E.; Aguirre, Julia M.; Bartell, Tonya Gau; Drake, Corey; Land, Tonia
2014-01-01
As part of a larger research project aimed at transforming preK-8 mathematics teacher preparation, the purpose of this study was to examine the extent to which prospective teachers notice children's competencies related to children's mathematical thinking, and children's community, cultural, and linguistic funds of knowledge or what…
Street, Garrett M.; Laubach, Timothy A.
2013-01-01
We provide a 5E structured-inquiry lesson so that students can learn more of the mathematics behind the logistic model of population biology. By using models and mathematics, students understand how population dynamics can be influenced by relatively simple changes in the environment.
Rattanatumma, Tawachai; Puncreobutr, Vichian
2016-01-01
The objective of this study was to compare the effectiveness of teaching methods in improving Mathematics Learning Achievement and Problem solving ability of students at an international college. This is a Quasi-Experimental Research which was done the study with the first year students who have registered to study Mathematics subject at St.…
Pieters, Stefanie; Roeyers, Herbert; Rosseel, Yves; Van Waelvelde, Hilde; Desoete, Annemie
2015-01-01
A relationship between motor and mathematical skills has been shown by previous research. However, the question of whether subtypes can be differentiated within developmental coordination disorder (DCD) and/or mathematical learning disability (MLD) remains unresolved. In a sample of children with and without DCD and/or MLD, a data-driven…
Visualization and mathematics III
Polthier, Konrad
2003-01-01
This research book on Mathematical Visualization contains state of the art presentations on visualization problems in mathematics, on fundamental mathematical research in computer graphics, and on software frameworks for the application of visualization to real-world problems. All contributions were written by leading experts in the field and peer-refereed by an international editorial team. The book grew out of the third international workshop "Visualization and Mathematics", which was held from May 22-25, 2002 in Berlin. The themes of the book cover important recent developments on - Geometry and Combinatorics of Meshes - Discrete Vector Fields and Topology - Geometric Modelling - Image Based Visualization - Software Environments and Applications - Education and Communication The variety of topics makes the book a suitable resource for researchers, lecturers, and practitioners; http://www-sfb288.math.tu-berlin.de/vismath/
Mathematical methods for physicists
Arfken, George B
2005-01-01
This best-selling title provides in one handy volume the essential mathematical tools and techniques used to solve problems in physics. It is a vital addition to the bookshelf of any serious student of physics or research professional in the field. The authors have put considerable effort into revamping this new edition.* Updates the leading graduate-level text in mathematical physics* Provides comprehensive coverage of the mathematics necessary for advanced study in physics and engineering* Focuses on problem-solving skills and offers a vast array of exercises * Clearly illustrates and proves mathematical relationsNew in the Sixth Edition:* Updated content throughout, based on users'' feedback * More advanced sections, including differential forms and the elegant forms of Maxwell''s equations* A new chapter on probability and statistics* More elementary sections have been deleted
Designing of the chemical composition of steels basing on the hardenability of constructional steels
International Nuclear Information System (INIS)
The paper presents the original method of modelling of the relationships between chemical composition of alloy constructional steel and its hardenability, employing neural networks. Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. (author)
DEFF Research Database (Denmark)
Carugati, Andrea
the boundary conditions of the most commonly used methodologies to understand whether they could be used for the development of systems based on (1) AMM and where the development organization is both (2) loosely coupled and (3) distributed. The boundary conditions identified for existing methodologies show...... that none of them is apt to deal with these three issues concurrently. The main goal, and hence the result, of this dissertation has therefore become the design of an information systems development methodology that concurrently addresses the issues of developing systems based on AMM and development...... to observe and analyze the workings of a development project. I have been working as part of the team assembled for the development of the information system based on AMM for a period of three years. My active participation in the development project granted me access to all the actors involved. In my role I...
Inquiry-Based Examination of Chemical Disruption of Bacterial Biofilms
Redelman, Carly V.; Hawkins, Misty A. W.; Drumwright, Franklin R.; Ransdell, Beverly; Marrs, Kathleen; Anderson, Gregory G.
2012-01-01
Inquiry-based instruction in the sciences has been demonstrated as a successful educational strategy to use for both high school and college science classrooms. As participants in the NSF Graduate STEM Fellows in K-12 Education (GK-12) Program, we were tasked with creating novel inquiry-based activities for high school classrooms. As a way to…
SYNTHESIS OF PROTEINS BY NATIVE CHEMICAL LIGATION USING FMOC-BASED CHEMISTRY
Energy Technology Data Exchange (ETDEWEB)
Camarero, J A; Mitchell, A R
2005-01-20
C-terminal peptide {alpha}-thioesters are valuable intermediates in the synthesis/semisynthesis of proteins by native chemical ligation. They are prepared either by solid-phase peptide synthesis (SPPS) or biosynthetically by protein splicing techniques. The present paper reviews the different methods available for the chemical synthesis of peptide {alpha}-thioesters using Fmoc-based SPPS.
Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game
Orbey, Nese; Clay, Molly; Russell, T.W. Fraser
2014-01-01
An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…
77 FR 18752 - Benzidine-Based Chemical Substances; Di-n
2012-03-28
...'-[2-(2-hydroxy-1- naphthalenyl)diazenyl][1,1 '-biphenyl]-4-yl]diazenyl]- , lithium salt (1:3) 68214-82...)(2) SNUR for the benzidine-based chemical substances listed at Sec. 721.1660 (61 FR 52287, October 7...; Significant New Uses of Certain Chemical Substances; Final Rule (61 FR 52287, October 7, 1996). F. What...
Dialogue-Based Activities and Manipulatives to Engage Liberal Arts Majors in Mathematics
Price, James C.
2015-01-01
This article presents four inquiry-based learning activities developed for a liberal arts math course. The activities cover four topics: the Pythagorean theorem, interest theory, optimization, and the Monty Hall problem. Each activity consists of a dialogue, with a theme and characters related to the topic, and a manipulative, that allow students…
Xavier, P.; Annaraja, P.
2007-01-01
Multiple Intelligence Based Teaching (MIBT) applies the multiple intelligence theory in the process of teaching and learning. MIBT explores and develops the intelligence of the students. Also, it teaches the content in a multiple way to the students. The objective of the present study is to find out the effectiveness of multiple intelligence based…
Mathematization in introductory physics
Brahmia, Suzanne M.
doing physics. It contrasts with their more common experience with mathematics as the practice of specified procedures to improve efficiency. This paper describes new curricular materials based on invention instruction provide students with opportunities to generate mathematical relationships in physics, and the paper presents preliminary evidence of the effectiveness of this method with mathematically underprepared engineering students.
Monaghan, John
2013-01-01
This paper offers a framework, an extension of Valsiner's "zone theory", for the analysis of joint student-teacher development over a series of technology-based mathematics lessons. The framework is suitable for developing research studies over a moderately long period of time and considers interrelated student-teacher development as…
Robinson, Michael; Tibanyendera, Basil; Seltzer-Kelly, Debbie
2007-01-01
This article reports the effects of a science, technology, and society (STS) teaching approach on the knowledge and attitudes of preservice science and mathematics teachers in Uganda toward global science and technology-based problems and/or threats. The responses of a baseline or control group (N = 50) and an experimental group (N = 50) to five…
Braden, Sharon Smith
2012-01-01
The purpose of this research was to investigate the differences in perceptions of learning and achievement of students and teachers in "Project-Based Learning" and Balanced Mathematics classrooms. The study utilized quantitative and qualitative surveys or a mixed method approach to gathering data relative to the perceptions of students…
Directory of Open Access Journals (Sweden)
Olga A. Iarmonova
2013-01-01
Full Text Available A fast mathematical model simulation module based on LabVIEW graphical programming environment has been developed. The module will be used for gas turbine and electrical power system co-simulation, and for testing automation of gas turbine automatic control systems.
Mathematical Modeling and Simulation of SWRO Process Based on Simultaneous Method
Jiang, Aipeng; Ding, Qiang; Wang, Jian; Jiangzhou, Shu; Cheng, Wen; Xing, Changxin
2014-01-01
Reverse osmosis (RO) technique is one of the most efficient ways for seawater desalination to solve the shortage of freshwater. For prediction and analysis of the performance of seawater reverse osmosis (SWRO) process, an accurate and detailed model based on the solution-diffusion and mass transfer theory is established. Since the accurate formulation of the model includes many differential equations and strong nonlinear equations (differential and algebraic equations, DAEs), to solve the pro...
Mathematical Modeling and Simulation of SWRO Process Based on Simultaneous Method
Aipeng Jiang; Qiang Ding; Jian Wang; Shu Jiangzhou; Wen Cheng; Changxin Xing
2013-01-01
Reverse osmosis (RO) technique is one of the most efficient ways for seawater desalination to solve the shortage of freshwater. For prediction and analysis of the performance of seawater reverse osmosis (SWRO) process, an accurate and detailed model based on the solution-diffusion and mass transfer theory is established. Since the accurate formulation of the model includes many differential equations and strong nonlinear equations (differential and algebraic equations, DAEs), to solve the pro...
Mathematical Modeling of a developed Central Receiver Based on Evacuated Solar Tubes
Ali Basil. H.; Gilani S. I.; Al-Kayiem Hussain H.
2016-01-01
Solar central receiver plays a considerable role in the plant output power; it is one of the most important synthesis in the solar power tower plants. Its performance directly affects the efficiency of the entire solar power generation system. In this study, a new designed receiver model based on evacuated solar tube was proposed, and the dynamic characteristics of the developed receiver were investigated. In order to optimise and evaluate the dynamic characteristics of solar power plant comp...
Witt, Marcus
2011-01-01
Working memory is a complex cognitive system responsible for the concurrent storage and processing of information. Ggiven that a complex cognitive task like mental arithmetic clearly places demands on working memory (e.g., in remembering partial results, monitoring progress through a multi-step calculation), there is surprisingly little research exploring the possibility of increasing young children’s working memory capacity through systematic school-based training. Tthis study reports the pr...
Jost, Jürgen
2015-01-01
The main intention of this book is to describe and develop the conceptual, structural and abstract thinking of mathematics. Specific mathematical structures are used to illustrate the conceptual approach; providing a deeper insight into mutual relationships and abstract common features. These ideas are carefully motivated, explained and illustrated by examples so that many of the more technical proofs can be omitted. The book can therefore be used: · simply as an overview of the panorama of mathematical structures and the relations between them, to be supplemented by more detailed texts whenever you want to acquire a working knowledge of some structure · by itself as a first introduction to abstract mathematics · together with existing textbooks, to put their results into a more general perspective · to gain a new and hopefully deeper perspective after having studied such textbooks Mathematical Concepts has a broader scope and is less detaile...
Chemical spill responder's use of website data bases
International Nuclear Information System (INIS)
The Emergency Response Team (ERT) of the US Environmental Protection Agency provides technical assistance to state and local government agencies. It has also provided hazardous waste and emergency response assistance to countries in North America, Central America, South America, Europe, Africa and Asia. In order to address the increased level of involvement in multi-governmental response activities and counter terrorist incidents, ERT has developed a responder's technical assistance website. The site contains 6 links that can be divided into the following three information support areas: (1) generation information about ERT, (2) a response resources site which provides information regarding air sampling, monitoring plans, phytoremediation, and information related to oil spill incidents where physical and chemical properties of specific petroleum products are needed. The health and safety section of this site links to the Environment Canada Emergencies Science Division (ESD) website. The ESD site has a document entitled Properties of Crude Oils and Oil Products which provides information on Louisiana crude. This site also provides links to all Federal agency websites that have hazardous waste operations and emergency response requirements or guidelines, and (3) the Weather Information Program (WIP) and Response Operation and Validation Retriever (ROVR) service which provides interactive response pages for Federal on-scene coordinators, remedial project managers and the general public. This paper also described the next generation of ROVR and WIP interactive function involving real-time on-site air plume modeling
Qingtongxia Aluminum Carrying Out Off-site Renovation in Ningdong Energy & Chemical Base
Institute of Scientific and Technical Information of China (English)
2008-01-01
<正>Recently,the off-site renovation project of Qingtongxia Aluminum commenced the con- struction in Linhe General Industrial Park of Ningdong Energy & Chemical Base,symboliz- ing a concrete step of Qingtongxia Aluminum
Advances and trends in ionophore-based chemical sensors
Mikhelson, K. N.; Peshkova, M. A.
2015-06-01
The recent advances in the theory and practice of potentiometric, conductometric and optical sensors based on ionophores are critically reviewed. The role of the heterogeneity of the sensor/sample systems is emphasized, and it is shown that due to this heterogeneity such sensors respond to the analyte activities rather than to concentrations. The basics of the origin of the response of all three kinds of ionophore-based sensors are briefly described. The use of novel sensor materials, new preparation and application techniques of the sensors as well as advances in theoretical treatment of the sensor response are analyzed using literature sources published mainly from 2012 to 2014. The basic achievements made in the past are also addressed when necessary for better understanding of the trends in the field of ionophore-based sensors. The bibliography includes 295 references.
Vivaldi, Franco
2014-01-01
This book teaches the art of writing mathematics, an essential -and difficult- skill for any mathematics student. The book begins with an informal introduction on basic writing principles and a review of the essential dictionary for mathematics. Writing techniques are developed gradually, from the small to the large: words, phrases, sentences, paragraphs, to end with short compositions. These may represent the introduction of a concept, the abstract of a presentation or the proof of a theorem. Along the way the student will learn how to establish a coherent notation, mix words and symbols effectively, write neat formulae, and structure a definition. Some elements of logic and all common methods of proofs are featured, including various versions of induction and existence proofs. The book concludes with advice on specific aspects of thesis writing (choosing of a title, composing an abstract, compiling a bibliography) illustrated by large number of real-life examples. Many exercises are included; over 150...
Cahill, Kevin
2013-01-01
Unique in its clarity, examples and range, Physical Mathematics explains as simply as possible the mathematics that graduate students and professional physicists need in their courses and research. The author illustrates the mathematics with numerous physical examples drawn from contemporary research. In addition to basic subjects such as linear algebra, Fourier analysis, complex variables, differential equations and Bessel functions, this textbook covers topics such as the singular-value decomposition, Lie algebras, the tensors and forms of general relativity, the central limit theorem and Kolmogorov test of statistics, the Monte Carlo methods of experimental and theoretical physics, the renormalization group of condensed-matter physics and the functional derivatives and Feynman path integrals of quantum field theory.
Faria, Ana; Bateira, Carlos; Laura, Soares; Fernandes, Joana; Gonçalves, José; Marques, Fernando
2016-04-01
The work focuses the evaluation of landslide susceptibility in Douro Region agricultural terraces, supported by dry stone walls and earth embankments, using two physically based models. The applied models, SHALSTAB (Montgomery et al.,1994; Dietrich et al., 1995) and SINMAP (PACK et al., 2005), combine an infinite slope stability model with a steady state hydrological model, and both use the following geophysical parameters: cohesion, friction angle, specific weight and soil thickness. The definition of the contributing areas is different in both models. The D∞ methodology used by SINMAP model suggests a great influence of the terraces morphology, providing a much more diffuse flow on the internal flow modelling. The MD8 used in SHALSTAB promotes an important degree of flow concentration, representing an internal flow based on preferential paths of the runoff as the areas more susceptible to saturation processes. The model validation is made through the contingency matrix method (Fawcett, 2006; Raia et al., 2014) and implies the confrontation with the inventory of past landslides. The True Positive Rate shows that SHALSTAB classifies 77% of the landslides on the high susceptibility areas, while SINMAP reaches 90%. The SINMAP has a False Positive Rate (represents the percentage of the slipped area that is classified as unstable but without landslides) of 83% and the SHALSTAB has 67%. The reliability (analyzes the areas that were correctly classified on the total area) of SHALSTAB is better (33% against 18% of SINMAP). Relative to Precision (refers to the ratio of the slipped area correctly classified over the whole area classified as unstable) SHALSTAB has better results (0.00298 against 0.00283 of SINMAP). It was elaborate the index TPR/FPR and better results obtained by SHALSTAB (1.14 against 1.09 of SINMAP). SHALSTAB shows a better performance in the definition of susceptibility most prone areas to instability processes. One of the reasons for the difference of
The Internet accessible mathematical computation framework
Institute of Scientific and Technical Information of China (English)
Paul S. Wang; Simon Gray; Norbert Kajler; Dongdai Lin; Weidong Liao; Xiao Zou
2004-01-01
The Internet Accessible Mathematical Computation (IAMC) framework aims to make it easy to supply mathematical computing powers over the Internet/Web. The protocol-based IAMC framework enables developers to create interoperable clients and servers easily and independently. Presented are conceptual and experimental work on the IAMC framework architecture and major components: the Mathematical Computation Protocol (MCP), a client prototype (Dragonfly), a server prototype (Starfish), a mathematical encoding converter (XMEC), and an open mathematical compute engine interface (OMEI).
Engineering Model Reduction and Entropy-based Lyapunov Functions in Chemical Reaction Kinetics
Hangos, Katalin M.
2010-01-01
In this paper, the structural properties of chemical reaction systems obeying the mass action law are investigated and related to the physical and chemical properties of the system. An entropy-based Lyapunov function candidate serves as a tool for proving structural stability, the existence of which is guaranteed by the second law of thermodynamics. The commonly used engineering model reduction methods, the so-called quasi equilibrium and quasi steady state assumption based reductions, togeth...
Electronic and chemical properties of graphene-based structures:
DEFF Research Database (Denmark)
Vanin, Marco
In the present thesis several aspects of graphene-based structures have been investigated using density functional theory calculations to solve the electronic structure problem. A review of the implementation of a localized basis-set within the projector augmented wave method - the way of describ...... are attractive candidates although issues regarding the poisoning of the active site remain to be addressed....
Bartocci, Claudio; Guerraggio, Angelo; Lucchetti, Roberto; Williams, Kim
2011-01-01
Steps forward in mathematics often reverberate in other scientific disciplines, and give rise to innovative conceptual developments or find surprising technological applications. This volume brings to the forefront some of the proponents of the mathematics of the twentieth century, who have put at our disposal new and powerful instruments for investigating the reality around us. The portraits present people who have impressive charisma and wide-ranging cultural interests, who are passionate about defending the importance of their own research, are sensitive to beauty, and attentive to the soci
Green, George
2005-01-01
An almost entirely self-taught mathematical genius, George Green (1793 -1841) is best known for Green's theorem, which is used in almost all computer codes that solve partial differential equations. He also published influential essays, or papers, in the fields of hydrodynamics, electricity, and magnetism. This collection comprises his most significant works.The first paper, ""An Essay on the Application of Mathematical Analysis to the Theories of Electricity and Magnetism,"" which is also the longest and perhaps the most Important, appeared In 1828. It introduced the term potential as desig
DEFF Research Database (Denmark)
Triantafyllou, Evangelia; Misfeldt, Morten; Timcenko, Olga
2015-01-01
approach in didactics. This theoretical framework defines the “atoms” of mathematical practice and discourse in terms of tasks, techniques, technologies and theories. We present a didactical scenario when Unity is used for introducing the calculation of reflection and refraction vectors and then we use...... the anthropological approach to present the practices in calculating these vectors with traditional mathematics and constructing them in Unity. Then, we discuss the differences between the two cases, when we argue that Unity can benefit Media Technology students, who use mathematics as a tool. However...
Mathematical definition of general systems based on semiotics and set theory (part of statics)
Zou, D D
2009-01-01
According to the relation between objects and time, our category of general systems theory was divided into three parts: statics, kinematics, and dynamics. In this part, beginning with clarifying fundamental in epistemology and semiotics, we gave the connections of measurements, partitions and functions. And conforming to customs, we defined the terms of quantity and value by our understanding of functions. Then the concept of relation quantity was coined to describe the relationship like distance and force. Farther more, we discussed correspondences established between two quantities, and the definitions and theorems of complete set based on it. Finally, we present the structure which can afford the obligation of general system, and also the definitions of subsystem and isomorphism.
On religion and language evolutions seen through mathematical and agent based models
Ausloos, M
2011-01-01
(shortened version) Religions and languages are social variables, like age, sex, wealth or political opinions, to be studied like any other organizational parameter. In fact, religiosity is one of the most important sociological aspects of populations. Languages are also a characteristics of the human kind. New religions, new languages appear though others disappear. All religions and languages evolve when they adapt to the society developments. On the other hand, the number of adherents of a given religion, the number of persons speaking a language is not fixed. Several questions can be raised. E.g. from a macroscopic point of view : How many religions/languages exist at a given time? What is their distribution? What is their life time? How do they evolve?. From a microscopic view point: can one invent agent based models to describe macroscopic aspects? Does it exist simple evolution equations? It is intuitively accepted, but also found through from statistical analysis of the frequency distribution that an ...
Institute of Scientific and Technical Information of China (English)
Gao Ning; Sun Wei
2015-01-01
Based on the study of supply chain (SC) and SC optimization in engineering projects, a mixed integer nonlinear programming (MINLP) optimization model is developed to minimize the total SC cost for international petrochemical en-gineering projects. A steam cracking project is selected and analyzed, from which typical SC characteristics in international engineering projects in the area of petrochemical industry are summarized. The MINLP model is therefore developed and applied to projects with detailed data. The optimization results are analyzed and compared by the MINLP model, indicat-ing that they are appropriate to SC management practice in engineering projects, and are consistent with the optimal price-effective strategy in procurement. As a result, the model could provide useful guidance to SC optimization of international engineering projects in petrochemical industry, and improve SC management by selecting more reliable and qualiifed part-ner enterprises in SC for the project.
Mathematical Model For Autoclave Curing Of Unsaturated Polyester Based Composite Materials
Directory of Open Access Journals (Sweden)
Adnan A. Abdul Razak
2013-05-01
Full Text Available Heat transfer process involved in the autoclave curing of fiber-reinforced thermosetting composites is investigated numerically. A model for the prediction of the temperature and the extent of the reaction across the laminate thickness during curing process in the autoclave of unsaturated polyester based composite has been developed. The governing equation for one dimensional heat transfer, and accounting for the heat generation due to the exothermic cure reaction in the composites had been used. It was found that the temperature at the central of the laminate increases up to the external imposed temperature, because of the thermal conductivity of the resin and fiber. The heat generated by the exothermic reaction of the resin is not adequately removed; the increase in the temperature at the center increases the resins rate reaction, which in turn generates more heat.
Mathematical Modeling of a developed Central Receiver Based on Evacuated Solar Tubes
Directory of Open Access Journals (Sweden)
Ali Basil. H.
2016-01-01
Full Text Available Solar central receiver plays a considerable role in the plant output power; it is one of the most important synthesis in the solar power tower plants. Its performance directly affects the efficiency of the entire solar power generation system. In this study, a new designed receiver model based on evacuated solar tube was proposed, and the dynamic characteristics of the developed receiver were investigated. In order to optimise and evaluate the dynamic characteristics of solar power plant components, the model investigates the solar radiation heat conversion process through the developed receiver, where the energy and mass conservation equations are used to determine the working fluid temperature and state through the receiver parts, beside the calculation and analysis of the thermal losses.
Semiconductor device-based sensors for gas, chemical, and biomedical applications
Ren, Fan
2011-01-01
Sales of U.S. chemical sensors represent the largest segment of the multi-billion-dollar global sensor market, which includes instruments for chemical detection in gases and liquids, biosensors, and medical sensors. Although silicon-based devices have dominated the field, they are limited by their general inability to operate in harsh environments faced with factors such as high temperature and pressure. Exploring how and why these instruments have become a major player, Semiconductor Device-Based Sensors for Gas, Chemical, and Biomedical Applications presents the latest research, including or
Mindfulness-based cognitive therapy for multiple chemical sensitivity
DEFF Research Database (Denmark)
Hauge, Christian R; Bonde, Jens Peter E; Rasmussen, Alice;
2012-01-01
no evidence-based treatments for MCS. Nevertheless, there is a substantial need for a treatment, because the condition can be severely disabling and can greatly reduce the quality of life (QOL) for those affected.In this study, we aim to assess the effects of a mindfulness-based cognitive therapy...... (MBCT) program on the impact of MCS on the participants' lives, symptoms, QOL, perceived stress, psychological distress, illness perceptions, and work ability. METHODS: Using a randomized controlled design (RCT), we will compare MBCT with treatment as usual (TAU). The MBCT intervention will include 8...... or to TAU. The primary outcome measure will be the impact of MCS on the participants' lives. The secondary outcome measures are symptoms of psychological distress, perceived stress, illness perceptions, QOL, and work ability. Lastly, we will assess whether any effect of MBCT on the primary effect...
The EDKB: an established knowledge base for endocrine disrupting chemicals
Bearden Edward D; Harris Steve; Perkins Roger; Hong Huixiao; Fang Hong; Xu Lei; Ding Don; Shi Leming; Tong Weida
2010-01-01
Abstract Background Endocrine disruptors (EDs) and their broad range of potential adverse effects in humans and other animals have been a concern for nearly two decades. Many putative EDs are widely used in commercial products regulated by the Food and Drug Administration (FDA) such as food packaging materials, ingredients of cosmetics, medical and dental devices, and drugs. The Endocrine Disruptor Knowledge Base (EDKB) project was initiated in the mid 1990’s by the FDA as a resource for the ...
Thin metal films in resistivity-based chemical sensing
Podešva, P. (Pavel); Foret, F
2013-01-01
Thin metal layers are widely utilized in a number of modern applications in electronics, optics, chemistry and many other applications. At present the thin layers of metals serve in applications spanning from simple electrodes to surface plasmon resonance (SPR) or giant magnetoresistance (GMR) based sensors [1, 2]. Thin films allow monitoring redox processes in the vicinity of electrodes, adsorption/desorption equilibria of ions, organic compounds, gases, and more recently also interactio...
Real, Joaquin; Morales, Marco; Garcia, Alicia; Garofano, Virginia; Martinez-Capel, Francisco; Frances, Felix
2010-05-01
Initially riparian vegetation modeling was focused on the study of ecological patches without taking into account the interactive effects of structures and processes in between them (Tabacchi et al., 1998). One of the greatest challenges, when carrying out a riparian ecosystem restoration, is to understand the physical and ecological processes of a system and the interaction and feedback within these processes. Jorde (2002) pointed out the importance of addressing complex linkages between processes and biotic interactions in research and in the development of restoration projects over larger spatial and temporal scales in the future. According to Tabacchi et al. (2000), the water cycle in riparian zones depends on three important relations: the water absorption by the plants, water storage and atmospherical return by evaporation. During recent years a variety of ecological models have taken into account the changes in the plant species as consequence of changes in the environmental variables and hydrological alterations (Baptist, 2005; Braatne et al., 2002; Glenz, 2005; Hooke et al., 2005; Murphy et al., 2006). Most of these models are based on functional relationships between river hydrology and vegetation species or communities. In semiarid regions we make the hypothesis transpiration will be one of the key factors determining the riparian vegetation presence and therefore, we will not consider in our model other factors as recruitment, flood damages, etc. The objectives of this work are: firstly to develop a model capable of simulating several riparian vegetation types which can be applied in a wide range of conditions across Mediterranean environments; and secondly to calibrate and to validate the model in several Mediterranean river stretches of the Iberian Peninsula, both in undisturbed and disturbed flow regimes. To achieve these objectives the following methodology has been applied. The model has been conceptualized as a static tank flow model based on the
Systematic quantum chemical study of DNA-base tautomers.
Piacenza, M; Grimme, S
2004-01-15
The relative energies of the energetically low-lying tautomers of pyridone, cytosine, uracil, thymine, guanine, and iso-cytosine are studied by a variety of different quantum chemical methods. In particular, we employ density functional theory (DFT) using the six functionals HCTH407, PBE, BP86, B-LYP, B3-LYP, and BH-LYP, and the ab initio methods Hartree-Fock (HF), standard second-order Møller-Plesset perturbation theory (MP2), an improved version of it (SCS-MP2), and quadratic configuration interaction including single and double excitations (QCISD) and perturbative triple corrections [QCISD(T)]. A detailed basis set study is performed for the formamide/formamidic acid tautomeric pair. In general, large AO basis sets of at least valence triple-zeta quality including f-functions (TZV) are employed, which are found to be necessary for an accurate energetic description of the various structures. The performance of the more approximate methods is evaluated with QCISD(T)/TZV(2df,2dp) data taken as reference. In general it is found that DFT is not an appropriate method for the problem. For the tautomers of pyridone and cytosine, most density functionals, including the popular B3-LYP hybrid, predict a wrong energetic order, and only for guanine, the correct sequence of tautomers is obtained with all functionals. Out of the density functionals tested, BH-LYP, which includes a rather large fraction of HF exchange, performs best. A consistent description of the nonaromatic versus aromatic tautomers seems to be a general problem especially for pure, nonhybrid functionals. Tentatively, this could be assigned to the exchange potentials used while the functional itself, including the correlation part, seems to be appropriate. Out of the ab initio methods tested, the new SCS-MP2 approach seems to perform best because it effectively reduces some outliers obtained with standard MP2. It outperforms the much more costly QCISD method and seems to be a very good compromise between
Directory of Open Access Journals (Sweden)
Ines Thiele
2009-03-01
Full Text Available Metabolic network reconstructions represent valuable scaffolds for '-omics' data integration and are used to computationally interrogate network properties. However, they do not explicitly account for the synthesis of macromolecules (i.e., proteins and RNA. Here, we present the first genome-scale, fine-grained reconstruction of Escherichia coli's transcriptional and translational machinery, which produces 423 functional gene products in a sequence-specific manner and accounts for all necessary chemical transformations. Legacy data from over 500 publications and three databases were reviewed, and many pathways were considered, including stable RNA maturation and modification, protein complex formation, and iron-sulfur cluster biogenesis. This reconstruction represents the most comprehensive knowledge base for these important cellular functions in E. coli and is unique in its scope. Furthermore, it was converted into a mathematical model and used to: (1 quantitatively integrate gene expression data as reaction constraints and (2 compute functional network states, which were compared to reported experimental data. For example, the model predicted accurately the ribosome production, without any parameterization. Also, in silico rRNA operon deletion suggested that a high RNA polymerase density on the remaining rRNA operons is needed to reproduce the reported experimental ribosome numbers. Moreover, functional protein modules were determined, and many were found to contain gene products from multiple subsystems, highlighting the functional interaction of these proteins. This genome-scale reconstruction of E. coli's transcriptional and translational machinery presents a milestone in systems biology because it will enable quantitative integration of '-omics' datasets and thus the study of the mechanistic principles underlying the genotype-phenotype relationship.
Typhoon eye trajectory based on a mathematical model: comparing with observational data
Rozanova, Olga S; Hu, Chin-Kun
2010-01-01
We propose a model based on the primitive system of the Navier-Stokes equations in a bidimensional framework as the $l$ - plane approximation, which allows us to explain the variety of tracks of tropical cyclones (typhoons). Our idea is to construct special analytical solutions with a linear velocity profile for the Navier-Stokes systems. The evidence of the structure of linear velocity near the center of vortex can be proven by the observational data. We study solutions with the linear-velocity property for both barotropic and baroclinic cases and show that they follow the same equations in describing the trajectories of the typhoon eye at the equilibrium state (that relates to the conservative phase of the typhoon dynamics). Moreover, at the equilibrium state, the trajectories can be viewed as a superposition of two circular motions: one has period $2\\pi/l,$ the other one has period $2\\pi/b_0,$ where $l$ is the Coriolis parameter and $b_0$ is the height-averaged vorticity at the center of cyclone. Also, we ...
Mathematical Modeling and Simulation of SWRO Process Based on Simultaneous Method
Directory of Open Access Journals (Sweden)
Aipeng Jiang
2014-01-01
Full Text Available Reverse osmosis (RO technique is one of the most efficient ways for seawater desalination to solve the shortage of freshwater. For prediction and analysis of the performance of seawater reverse osmosis (SWRO process, an accurate and detailed model based on the solution-diffusion and mass transfer theory is established. Since the accurate formulation of the model includes many differential equations and strong nonlinear equations (differential and algebraic equations, DAEs, to solve the problem efficiently, the simultaneous method through orthogonal collocation on finite elements and large scale solver were used to obtain the solutions. The model was fully discretized into NLP (nonlinear programming with large scale variables and equations, and then the NLP was solved by large scale solver of IPOPT. Validation of the formulated model and solution method is verified by case study on a SWRO plant. Then simulation and analysis are carried out to demonstrate the performance of reverse osmosis process; operational conditions such as feed pressure and feed flow rate as well as feed temperature are also analyzed. This work is of significant meaning for the detailed understanding of RO process and future energy saving through operational optimization.
International Nuclear Information System (INIS)
Radon-222 is a radionuclide exhaled from phosphogypsum by-produced at phosphate fertilizer industries. Alternative large-scale application of this waste may indicate a material substitute for civil engineering provided that environmental issues concerning its disposal and management are overcome. The first part of this paper outlines a steady-state two-dimensional model for 222Rn transport through porous media, inside which emanation (source term) and decay (sink term) exist. Boussinesq approach is evoked for the laminar buoyancy-driven interstitial air flow, which is also modeled according to Darcy-Brinkman formulation. In order to account for simultaneous effects of entailed physical parameters, governing equations are cast into dimensionless form. Apart from usual controlling parameters like Reynolds, Prandtl, Schmidt, Grashof and Darcy numbers, three unconventional dimensionless groups are put forward. Having in mind 222Rn transport in phosphogypsum-bearing porous media, the physical meaning of those newly introduced parameters and representative values for the involved physical parameters are presented. A limiting diffusion-dominated scenario is addressed, for which an analytical solution is deduced for boundary conditions including an impermeable phosphogypsum stack base and a non-zero fixed concentration activity at the stack top. Accordingly, an expression for the average Sherwood number corresponding to the normalized 222Rn exhalation rate is presented
Vogt, Gregory L.
2001-01-01
If you go to the country, far from city lights, you can see about 3,000 stars on a clear night. If your eyes were bigger, you could see many more stars. With a pair of binoculars, an optical device that effectively enlarges the pupil of your eye by about 30 times, the number of stars you can see increases to the tens of thousands. With a medium-sized telescope with a light-collecting mirror 30 centimeters in diameter, you can see hundreds of thousands of stars. With a large observatory telescope, millions of stars become visible. This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy--astronomical observations made from outer space. It is not intended to serve as a curriculum. Instead, teachers should select activities from this guide that support and extend existing study. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. It tells, rather, the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. Teachers are encouraged to adapt these activities for the particular needs of their students. When selected activities from this guide are used in conjunction with traditional astronomy curricula, students benefit from a more complete experience.
Directory of Open Access Journals (Sweden)
Atma Murni
2013-07-01
Full Text Available The aim of this study is to know the differences of enhancement inmathematical problem solving ability (MPSA between the studentswho received soft skill- based metacognitive learning (SSML with thestudents who got conventional learning (CL. This research is a quasiexperimental design with pretest-postest control group. The populationin this study is the students of Junior High School in Pekanbaru city.The sample consist of 135 students, 68 of them are from the high-levelschool, and 67 students are from the middle-level school. The instruments are mathematical prior knowledge (MPK test, MPSA test,instruction observation sheet, students journal about the lesson, and the guideline for interview. The data was analyzed using t-test and two way ANOVA. The result of data analysis indicates: (1 overall, theenhancement of students’ MPSA with SSML approach significantly ishigher than those with conventional learning (CL; (2 there is nointeraction between the learning approach (SSML and CL with theschool level (high and middle toward the enhancement of MPSA; (3there is no interaction between the learning approach (SSML and CLwith MPK (upper, middle, and low toward the enhancement of MPSA.
Rodenbusch, Stacia E; Hernandez, Paul R; Simmons, Sarah L; Dolan, Erin L
2016-01-01
National efforts to transform undergraduate biology education call for research experiences to be an integral component of learning for all students. Course-based undergraduate research experiences, or CUREs, have been championed for engaging students in research at a scale that is not possible through apprenticeships in faculty research laboratories. Yet there are few if any studies that examine the long-term effects of participating in CUREs on desired student outcomes, such as graduating from college and completing a science, technology, engineering, and mathematics (STEM) major. One CURE program, the Freshman Research Initiative (FRI), has engaged thousands of first-year undergraduates over the past decade. Using propensity score-matching to control for student-level differences, we tested the effect of participating in FRI on students' probability of graduating with a STEM degree, probability of graduating within 6 yr, and grade point average (GPA) at graduation. Students who completed all three semesters of FRI were significantly more likely than their non-FRI peers to earn a STEM degree and graduate within 6 yr. FRI had no significant effect on students' GPAs at graduation. The effects were similar for diverse students. These results provide the most robust and best-controlled evidence to date to support calls for early involvement of undergraduates in research. PMID:27252296
Zhang, Zili; Gao, Chao; Liu, Yuxin; Qian, Tao
2014-09-01
Ant colony optimization (ACO) algorithms often fall into the local optimal solution and have lower search efficiency for solving the travelling salesman problem (TSP). According to these shortcomings, this paper proposes a universal optimization strategy for updating the pheromone matrix in the ACO algorithms. The new optimization strategy takes advantages of the unique feature of critical paths reserved in the process of evolving adaptive networks of the Physarum-inspired mathematical model (PMM). The optimized algorithms, denoted as PMACO algorithms, can enhance the amount of pheromone in the critical paths and promote the exploitation of the optimal solution. Experimental results in synthetic and real networks show that the PMACO algorithms are more efficient and robust than the traditional ACO algorithms, which are adaptable to solve the TSP with single or multiple objectives. Meanwhile, we further analyse the influence of parameters on the performance of the PMACO algorithms. Based on these analyses, the best values of these parameters are worked out for the TSP. PMID:24613939
Directory of Open Access Journals (Sweden)
Mario Tirso Oscar Baltra San Martín
2010-05-01
Full Text Available This study analyzes the performance profile of Chilean city-school students from different socioeconomic strata, in relation to different sets of cognitive abilities specified in the curriculum framework for mathematics education in their country. The study is correlational and ex post facto in type, derived from the results of the math test of the System for Measuring Educational Quality (SIMCE applied to second-semester students of the 2001 school year. The percentage of students at each performance level was calculated, based on each student’s probability of correctly answering each of the test questions, using logistic function, associated with the two-parameter model of the Item Response Theory (IRT. The results show that regardless of the set of cognitive abilities in question, the performance profile follows a similar pattern. It was found that in general, there is a linear decrease in the percentage of those who achieve superior performances among students from low and medium-low strata, and exponential increases for middle-class students.
International Nuclear Information System (INIS)
Ant colony optimization (ACO) algorithms often fall into the local optimal solution and have lower search efficiency for solving the travelling salesman problem (TSP). According to these shortcomings, this paper proposes a universal optimization strategy for updating the pheromone matrix in the ACO algorithms. The new optimization strategy takes advantages of the unique feature of critical paths reserved in the process of evolving adaptive networks of the Physarum-inspired mathematical model (PMM). The optimized algorithms, denoted as PMACO algorithms, can enhance the amount of pheromone in the critical paths and promote the exploitation of the optimal solution. Experimental results in synthetic and real networks show that the PMACO algorithms are more efficient and robust than the traditional ACO algorithms, which are adaptable to solve the TSP with single or multiple objectives. Meanwhile, we further analyse the influence of parameters on the performance of the PMACO algorithms. Based on these analyses, the best values of these parameters are worked out for the TSP. (paper)
Representations used by mathematics student teachers in mathematical modeling process
Directory of Open Access Journals (Sweden)
Aytuğ Özaltun
2014-02-01
Full Text Available The purpose of this study is to determine representations used by mathematics student teachers in steps of mathematical modeling process based on their solutions of problems formed in the context of different classification of modeling. The study was conducted with fifteen secondary mathematics student teachers given a Mathematical Modeling course. The participants were separated into five collaboration groups of three students. Data were collected with the detailed written papers given by the groups for the problems and GeoGebra solution files. The groups benefited from verbal, algebraic, figural, tabular and dynamic representations while they were solving the problems. Considering all steps of the process, groups at most used verbal and algebraic representations. While they used only verbal representation in analyzing the problem, they benefited from at most verbal representation and then figural representation in establishing the systematic structure. The most used is algebraic and then verbal representations in the steps of mathematization, meta-mathematization, and mathematical analysis. In the steps of interpretation/evaluation and the model verification, the groups mainly benefited from verbal and then algebraic representations. Further researches towards why representations are preferred in the specific steps of the mathematical modeling process are suggested.Key Words: Mathematical modeling, modeling problems, mathematics student teachers, representations.
Hadlock, Charles R
2013-01-01
The movement of groundwater in underground aquifers is an ideal physical example of many important themes in mathematical modeling, ranging from general principles (like Occam's Razor) to specific techniques (such as geometry, linear equations, and the calculus). This article gives a self-contained introduction to groundwater modeling with…
Fujita, Shinsaku
2015-01-01
Chirality and stereogenicity are closely related concepts and their differentiation and description is still a challenge in chemoinformatics. A new stereoisogram approach, developed by the author, is introduced in this book, providing a theoretical framework for mathematical aspects of modern stereochemistry. The discussion covers point-groups and permutation symmetry and exemplifies the concepts using organic molecules and inorganic complexes.
St Hilaire, Melissa A.; Klerman, Elizabeth B.; Khalsa, Sat Bir; Wright, Kenneth P.; Czeisler, Charles A.; Kronauer, Richard E.
2007-01-01
Mathematical models have become vital to the study of many biological processes in humans due to the complexity of the physiological mechanisms underlying these processes and systems. While our current mathematical representation of the human circadian pacemaker has proven useful in many experimental situations, it uses as input only a direct effect of light on the circadian pacemaker. Although light (a photic stimulus) has been shown to be the primary synchronizer of the circadian pacemaker ...
Dmytro Stechenko; Olga Omelchenko
2013-01-01
The approach to the restructuring of engineering enterprises on the basis of economic and mathematical models complex and scenarios for its implementation are given in the article. The structure and features of the formation of organizational restructuring and economic provision are described. The components of economic and mathematical methods of restructuring are considered: a general model of restructuring, that determines the design of its planning, development and implementation; the ove...
International Nuclear Information System (INIS)
A new model has been developed in this work which is capable of simulating the precipitation kinetics of brittle phases, especially TCP-phases (topologically close packed phases) in ruthenium containing superalloys. The model simultaneously simulates the nucleation and the growth stage of precipitation for any number of precipitating phases. The CALPHAD method (Calculation of Phase Diagrams) is employed to calculate thermodynamic properties, such as the driving force or phase compositions in equilibrium. For calculation of diffusion coefficients, kinetic mobility databases which are also based on the CALPHAD-method are used. The model is fully capable of handling multicomponent effects, which are common in complex superalloys. Metastable phases can be treated and will automatically be dissolved if they get unstable. As the model is based on the general CALPHAD method, it can be applied to a broad range of precipitation processes in different alloys as long as the relevant thermodynamic and kinetic databases are available. The developed model proves that the TCP-phases precipitate in a sequence of phases. The first phase that is often formed is the metastable σ-phase because it has the lowest interface energy due to low-energy planes at the interface between matrix and precipitate. After several hundred hours the stable μ- and P-phases start to precipitate by nucleating at the σ-phase which is energetically favourable. During the growth of these stable phases the sigma-phase is continuously dissolved. It can be shown by thermodynamic CALPHAD calculations that the sigma-phase has a lower Gibbs free enthalpy than the μ- and P-phase. All required parameters of the model, such as interface energy and nucleate densities, have been estimated. The mechanisms of suppression of TCP-phase precipitation in the presence of ruthenium in superalloys were investigated with the newly developed model. It is shown by the simulations that ruthenium mostly affects the nucleation
基于数学任务情境的乐高机器人课程初探%Lego Robotics Course Based on Mathematical Task Situation
Institute of Scientific and Technical Information of China (English)
邱雅番
2012-01-01
随着机器人教育在我国基础教育的不断探索与实践，机器人走进了中小学的课堂，走进了不同的学科。笔者通过研读小学数学教材，以新课程标准为依据，将数学与机器人教学结合，设计出基于数学任务情境下的机器人课程，旨在让学生通过机器人制作与任务完成，形成数学学习的积极性和主动性。对一线从事机器人教育的教师具有一定的参考价值和实践指导意义。%Robotics education in basic education in China continues to explore and practice, the robot into the primary and secondary school classroom, into the different disciplines. Through the study of elementary school mathematics textbooks, the new curriculum standards based on the combination of mathematics and robot teaching robotics curriculum design based on the context of mathematical tasks, designed to allow students to be completed by robot production and tasks, the formation of mathematics learning enthusiasm and initiative. First-line robot education teachers with a certain reference value and practical significance.
DEFF Research Database (Denmark)
Haahr, Anne-Mette; Madsen, Henrik; Smedsgaard, Jørn;
2003-01-01
that of the flavor detection threshold. An application study on the release of menthone and menthol from chewing gum by a group of six test persons was performed. Flavored chewing gum was used as a model matrix because of the long chewing periods and the simplicity of the system. It is concluded that...... the interface and the method can be used to measure breath from the nose. A mathematical model of the data was developed to give a quantitative method for description and characterization of the release of flavor compounds. The release profiles consisted of two sequences, one for a chewing period, and...
Development of a chemical microthruster based on pulsed detonation
International Nuclear Information System (INIS)
The development of a microthruster based on gaseous pulsed detonation is presented in this study. The feasibility of cyclic valveless pulsed detonation at frequencies over 100 Hz is first experimentally investigated in a microchannel with 1 mm × 0.6 mm rectangular cross-section. Highly reactive ethylene/oxygen mixtures are utilized to reduce the time and distance required for the reaction wave to run up to detonation in a smooth channel. High-speed visualizations have shown that the reaction waves reach detonative state through highly repeatable flame acceleration and deflagration-to-detonation transition processes in the channel. The validated concepts are implemented for the development of an integrated pulsed detonation microthruster. The microthruster was fabricated using low temperature co-fired ceramic tape technology. The volume of the reaction channel in the microthruster was 58 mm3. Spark electrodes and ion probes were embedded in the ceramic microthruster. The channel and via holes were fabricated using laser cutting techniques. Ion probe measurements showed that the reaction wave propagated at velocities larger than 2000 m s−1 before reaching the channel exit. The pulsed detonation microthruster has been successfully operated at frequencies as high as 200 Hz. (paper)
Application-Oriented Chemical Optimization of a Metakaolin Based Geopolymer
Directory of Open Access Journals (Sweden)
Raffaele Cioffi
2013-05-01
Full Text Available In this study the development of a metakaolin based geopolymeric mortar to be used as bonding matrix for external strengthening of reinforced concrete beams is reported. Four geopolymer formulations have been obtained by varying the composition of the activating solution in terms of SiO2/Na2O ratio. The obtained samples have been characterized from a structural, microstructural and mechanical point of view. The differences in structure and microstructure have been correlated to the mechanical properties. A major issue of drying shrinkage has been encountered in the high Si/Al ratio samples. In the light of the characterization results, the optimal geopolymer composition was then applied to fasten steel fibers to reinforced concrete beams. The mechanical behavior of the strengthened reinforced beams was evaluated by four-points bending tests, which were performed also on reinforced concrete beams as they are for comparison. The preliminary results of the bending tests point out an excellent behavior of the geopolymeric mixture tested, with the failure load of the reinforced beams roughly twice that of the control beam.
Climate-based archetypes for the environmental fate assessment of chemicals.
Ciuffo, Biagio; Sala, Serenella
2013-11-15
Emissions of chemicals have been on the rise for years, and their impacts are greatly influenced by spatial differentiation. Chemicals are usually emitted locally but their impact can be felt both locally and globally, due to their chemical properties and persistence. The variability of environmental parameters in the emission compartment may affect the chemicals' fate and the exposure at different orders of magnitude. The assessment of the environmental fate of chemicals and the inherent spatial differentiation requires the use of multimedia models at various levels of complexity (from a simple box model to complex computational and high-spatial-resolution models). The objective of these models is to support ecological and human health risk assessment, by reducing the uncertainty of chemical impact assessments. The parameterisation of spatially resolved multimedia models is usually based on scenarios of evaluative environments, or on geographical resolutions related to administrative boundaries (e.g. countries/continents) or landscape areas (e.g. watersheds, eco-regions). The choice of the most appropriate scale and scenario is important from a management perspective, as a balance should be reached between a simplified approach and computationally intensive multimedia models. In this paper, which aims to go beyond the more traditional approach based on scale/resolution (cell, country, and basin), we propose and assess climate-based archetypes for the impact assessment of chemicals released in air. We define the archetypes based on the main drivers of spatial variability, which we systematically identify by adopting global sensitivity analysis techniques. A case study that uses the high resolution multimedia model MAPPE (Multimedia Assessment of Pollutant Pathways in the Environment) is presented. Results of the analysis showed that suitable archetypes should be both climate- and chemical-specific, as different chemicals (or groups of them) have different traits
KÖROĞLU, Hayrettin; YEŞİLDERE, Sibel
2004-01-01
The only way to be able to succeed in mathematics is to understand its nature. If you cannot discover the beauty of mathematics and make students curious about it, mathematics education may not be realized. The aim of mathematics must be solving to learn, not learning to solve. It is not possible to convince students that “mathematics is joyful” before they are made a part of it. Multiple Intelligences Theory may be useful to realize this part of mathematical charasteristics. Mathematics...
Novel fluorescence-based integrated sensor for chemical and biological agent detection
Frye-Mason, Greg; Leuschen, Martin; Wald, Lara; Paul, Kateri; Hancock, Lawrence F.; Fagan, Steve; Krouse, Justin; Hutchinson, Kira D.
2004-12-01
There is a renewed interest in the development of chemical and biological agent sensors due to the increased threat of weapons deployment by terrorist organizations and rogue states. Optically based sensors address the needs of military and homeland security forces in that they are reliable, rapidly deployed, and can provide continuous monitoring with little to no operator involvement. Nomadics has developed optically based chemical weapons sensors that utilize reactive fluorescent chromophores initially developed by Professor Tim Swager at MIT. The chromophores provide unprecedented sensitivity and selectivity toward toxic industrial chemicals and certain chemical weapon agents. The selectivity is based upon the reactivity of the G-class nerve agents (phosphorylation of acetylcholinesterase enzyme) that makes them toxic. Because the sensor recognizes the reactivity of strong electrophiles and not molecular weight, chemical affinity or ionizability, our system detects a specific class of reactive agents and will be able to detect newly developed or modified agents that are not currently known. We have recently extended this work to pursue a combined chemical/biological agent sensor system incorporating technologies based upon novel deep ultraviolet (UV) light emitting diodes (LEDs) developed out of the DARPA Semiconductor UV Optical Sources (SUVOS) program.
Mathematical simulation of oil reservoir properties
International Nuclear Information System (INIS)
The study and computational representation of porous media properties are very important for many industries where problems of fluid flow, percolation phenomena and liquid movement and stagnation are involved, for example, in building constructions, ore processing, chemical industries, mining, corrosion sciences, etc. Nevertheless, these kinds of processes present a noneasy behavior to be predicted and mathematical models must include statistical analysis, fractal and/or stochastic procedures to do it. This work shows the characterization of sandstone berea core samples which can be found as a porous media (PM) in natural oil reservoirs, rock formations, etc. and the development of a mathematical algorithm for simulating the anisotropic characteristics of a PM based on a stochastic distribution of some of their most important properties like porosity, permeability, pressure and saturation. Finally a stochastic process is used again to simulated the topography of an oil reservoir
Mathematical simulation of oil reservoir properties
Energy Technology Data Exchange (ETDEWEB)
Ramirez, A. [Instituto Politecnico Nacional (SEPI-ESQIE-UPALM-IPN), Unidad Profesional Zacatenco, Laboratorio de Analisis Met., Edif. ' Z' y Edif. 6 planta baja., Mexico City c.p. 07300 (Mexico)], E-mail: adalop123@mailbanamex.com; Romero, A.; Chavez, F. [Instituto Politecnico Nacional (SEPI-ESQIE-UPALM-IPN), Unidad Profesional Zacatenco, Laboratorio de Analisis Met., Edif. ' Z' y Edif. 6 planta baja., Mexico City c.p. 07300 (Mexico); Carrillo, F. [Instituto Politecnico Nacional (CICATA-IPN, Altamira Tamaulipas) (Mexico); Lopez, S. [Instituto Mexicano del Petroleo - Molecular Engineering Researcher (Mexico)
2008-11-15
The study and computational representation of porous media properties are very important for many industries where problems of fluid flow, percolation phenomena and liquid movement and stagnation are involved, for example, in building constructions, ore processing, chemical industries, mining, corrosion sciences, etc. Nevertheless, these kinds of processes present a noneasy behavior to be predicted and mathematical models must include statistical analysis, fractal and/or stochastic procedures to do it. This work shows the characterization of sandstone berea core samples which can be found as a porous media (PM) in natural oil reservoirs, rock formations, etc. and the development of a mathematical algorithm for simulating the anisotropic characteristics of a PM based on a stochastic distribution of some of their most important properties like porosity, permeability, pressure and saturation. Finally a stochastic process is used again to simulated the topography of an oil reservoir.
Mathematics for physics with calculus
Das, Biman
2005-01-01
Designed for students who plan to take or who are presently taking calculus-based physics courses. This book will develop necessary mathematical skills and help students gain the competence to use precalculus, calculus, vector algebra, vector calculus, and the statistical analysis of experimental data. Students taking intermediate physics, engineering, and other science courses will also find the book useful-and will be able to use the book as a mathematical resource for these intermediate level courses. The book emphasizes primarily the use of mathematical techniques and mathematical concepts in Physics and does not go into their rigorous developments.
An introduction to mathematical cryptography
Hoffstein, Jeffrey; Silverman, Joseph H
2014-01-01
This self-contained introduction to modern cryptography emphasizes the mathematics behind the theory of public key cryptosystems and digital signature schemes. The book focuses on these key topics while developing the mathematical tools needed for the construction and security analysis of diverse cryptosystems. Only basic linear algebra is required of the reader; techniques from algebra, number theory, and probability are introduced and developed as required. This text provides an ideal introduction for mathematics and computer science students to the mathematical foundations of modern cryptography. The book includes an extensive bibliography and index; supplementary materials are available online. The book covers a variety of topics that are considered central to mathematical cryptography. Key topics include: classical cryptographic constructions, such as Diffie–Hellmann key exchange, discrete logarithm-based cryptosystems, the RSA cryptosystem, and digital signatures; fundamental mathematical tools for cr...
DEFF Research Database (Denmark)
Mattei, Michele; Hill, Michael; Kontogeorgis, Georgios;
2013-01-01
An extended systematic methodology for the design of emulsion-based Chemical products is presented. The methodology consists of a model-based framework involving seven sequential hierarchical steps: starting with the identification of the needs to be satisfied by the product and then adding one......-by-one the different classes of chemicals, until a formulation is obtained, the stability of which as en emulsion is finally checked with appropriate models. Structured databases, appropriate pure component as well as mixture property models, rule-based selection criteria and CAMD techniques are employed...
Bartelet, Dimona; Ghysels, Joris; Groot, Wim; Haelermans, Carla; van den Brink, Henriëtte Maassen
2016-01-01
This article examines an educational experiment with a unique combination of 3 elements: homework, the use of information and communication technology and a large degree of freedom of choice (student autonomy). More particularly, we study the effectiveness of a web-based intelligent tutoring system (ITS) that a school offers to its students as…
Chemicals identified in human biological media: a data base. Third annual report, October 1981
Energy Technology Data Exchange (ETDEWEB)
Cone, M.V.; Baldauf, M.F.; Martin, F.M. (comps.)
1981-12-01
Data from almost 1600 of the 3800 body-burden documents collected to date have been entered in the data base as of October 1981. The emphasis on including recent literature and significant research documents has resulted in a chronological mix of articles from 1974 to the present. When body-burden articles are identified, data are extracted and entered in the data base by chemical and tissue/body fluid. Each data entry comprises a single record (or line entry) and is assigned a record number. If a particular document deals with more than one chemical and/or tissue, there will be multiple records for that document. For example, a study of 5 chemicals in each of 3 tissues has 15 different records (or 15 line entries) in the data base with 15 record numbers. Record numbers are assigned consecutively throughout the entire data base and appear in the upper left corner of the first column for each record.
基于几何与数学特征的人脸识别%Face recognition based on geometric and mathematics features
Institute of Scientific and Technical Information of China (English)
梁奔香; 蔡晓东; 朱利伟
2015-01-01
提出了一种新的基于几何与数学特征相融合的人脸识别算法，分别提出了眉毛几何特征、人脸个性几何特征以及数学特征在人脸比对时的比对策略，采用打分的机制记录特征比对的结果。为了融合几何与数学特征，提出了基于权值的几何特征与数学特征的融合策略。实验结果表明，采用几何特征与数学特征相融合进行人脸识别比使用单一人脸特征进行人脸识别时有更高的识别率。%Presents a new face recognition algorithm based on geometry and mathematical characteristics. The contrast strategy of the geometric feature of eyebrows, face personality geometry characteristics and the characteristics of mathematics were put forward. A weight scoring mechanism was used to record the comparison results of characteristics. In order to fusion with the facial geometric features and mathematical characteristics, a fusion strategy of the weights was proposed based on the geometrical characteristics and mathematical characteristics. The experimental results show that the geometric feature and the integration of mathematical characteristics for face recognition has higher recognition rate than using a single face feature for face recognition.
Resonant absorption of a chemically sensitive layer based on waveguide gratings
Davoine, Laurent; Paeder, Vincent; Basset, Guillaume; Schnieper, Marc; Herzig, Hans Peter
2013-01-01
A colorimetric sensor providing a direct visual indication of chemical contamination was developed. The sensor is a combination of a chemically sensitive dye layer and a resonant waveguide grating. Enhancement of the light absorption by the photonic structure can be clearly seen. The detection is based on the color change of the reflected light after exposure to a gas or a liquid. Low-cost fabrication and compatibility with environments where electricity cannot be used make this device very a...
Model based fault diagnosis for hybrid systems : application on chemical processes
Olivier Maget, Nelly; Hétreux, Gilles; Le Lann, Jean-Marc
2009-01-01
The complexity and the size of the industrial chemical processes induce the monitoring of a growing number of process variables. Their knowledge is generally based on the measurements of system variables and on the physico-chemical models of the process. Nevertheless, this information is imprecise because of process and measurement noise. So the research ways aim at developing new and more powerful techniques for the detection of process fault. In this work, we present a method for the fault ...