WorldWideScience

Sample records for twelfth grade material

  1. Omani Twelfth Grade Students' Most Common Misconceptions in Chemistry

    Science.gov (United States)

    Al-Balushi, Sulaiman M.; Ambusaidi, Abdullah K.; Al-Shuaili, Ali H.; Taylor, Neil

    2012-01-01

    The current study, undertaken in the Sultanate of Oman, explored twelfth grade students' common misconceptions in seven chemistry conceptual areas. The sample included 786 twelfth grade students in Oman while the instrument was a two-tier test called Chemistry Misconceptions Diagnostic Test (CMDT), consisting of 25 items with 12 items…

  2. Causal Factors Influencing Adversity Quotient of Twelfth Grade and Third-Year Vocational Students

    Science.gov (United States)

    Pangma, Rachapoom; Tayraukham, Sombat; Nuangchalerm, Prasart

    2009-01-01

    Problem statement: The aim of this research was to study the causal factors influencing students' adversity between twelfth grade and third-year vocational students in Sisaket province, Thailand. Six hundred and seventy two of twelfth grade and 376 third-year vocational students were selected by multi-stage random sampling techniques. Approach:…

  3. NAEP Fourth-, Eighth-, and Twelfth-Grade Reading Scores by Gender: 2005, 2007, 2009, 2011, 2013

    Science.gov (United States)

    Klecker, Beverly M.

    2014-01-01

    This paper describes a secondary analysis of the National Assessment of Educational Progress (NAEP) reading scores by gender. Data were national public 4th- and 8th-grade reading scores from composite and subscales for 2005, 2007, 2009, 2011, and 2013. Twelfth-grade scores for composite and literary experience from 2005, 2009, and 2013 and gain…

  4. Twelfth grade follow-up of the effectiveness of a middle school-based substance abuse prevention program.

    Science.gov (United States)

    Shope, J T; Copeland, L A; Kamp, M E; Lang, S W

    1998-01-01

    A twelfth-grade follow-up afforded the opportunity to assess the long-term effects of substance abuse prevention delivered in sixth and seventh grades. A social pressures resistance skills curriculum implemented by classroom teachers had been evaluated with short-term positive results previously reported. Students completed self-administered questionnaires at sixth grade pre- and posttests, and at seventh and twelfth-grade posttests. Curriculum group students received lessons on alcohol, tobacco (cigarettes and smokeless), marijuana, and cocaine, which were later incorporated into the Michigan Model for Comprehensive School Health Education. This evaluation used data from 262 students who completed all four questionnaires and who received the complete two-year intervention or no intervention. Repeated measures analyses of variance demonstrated that significant effects evident at seventh grade for alcohol use and misuse, as well as cigarette, cocaine, and other drug use were generally not maintained through twelfth grade. Ongoing reinforcement of effective prevention is recommended.

  5. Exploring the Effect of Reader Response Plus on Twelfth Grade Students with Disabilities' Reading Comprehension and Attitudes toward Reading

    Science.gov (United States)

    Granger, Noelle; Black, Alison; Miller, Jane

    2007-01-01

    The purpose of the study was to examine how reader response journals followed by classroom discussion ("Reader Response Plus") contributed to students' reading comprehension and to their attitudes toward reading. The study was conducted in a rural school in upstate New York. The twelfth grade class that participated in the study…

  6. Academic Adjustment of Gifted and Non-Gifted Ninth-, Tenth-, Eleventh-, and Twelfth-Grade Students Placed in Accelerated Mathematics Courses

    Science.gov (United States)

    Speer, Emily M.

    2013-01-01

    This study investigated the academic adjustment of gifted and non-gifted ninth-, tenth-, eleventh-, and twelfth-grade students placed in accelerated mathematics courses. Using Van Eman's research, the investigation of the social and emotional effects of mathematics acceleration through academic adjustment included the following positive indicators…

  7. Impact of writing about mathematics in a humanistic context on mathematical self-concept: A twelfth-grade pilot study

    Directory of Open Access Journals (Sweden)

    Kadijević Đorđe M.

    2004-01-01

    Full Text Available As one’s learning results from a complex interplay among his/her cognitive metacognitive and affective domains, the last of which determines the global context where cognition takes place monitored and controlled by metacognition, the learning outcomes may primarily be interpreted in affective terms. Having in mind a strong positive relation between mathematical self and mathematical achievement as well as that a humanistic approach to mathematics teaching/learning would promote higher mathematical self, this study examined whether writing about mathematics in a humanistic context influences mathematical self. This question was answered by comparing mathematical self of twelfth-grade gymnasium (high-school students who wrote their matura works on mathematical themes (N = 10 with that of their classmates who did that in other subjects (N = 72. A higher mathematical self was found for these ten students, which may be commented with "those who chose to write matura works in mathematics were simply those with higher mathematical self and the writing contributed nothing to the outcome". The values of other control variables measured in grades 9-12 evidence that it is more likely that this finding was influenced by the treatment.

  8. Functionally graded materials

    CERN Document Server

    Mahamood, Rasheedat Modupe

    2017-01-01

    This book presents the concept of functionally graded materials as well as their use and different fabrication processes. The authors describe the use of additive manufacturing technology for the production of very complex parts directly from the three dimension computer aided design of the part by adding material layer after layer. A case study is also presented in the book on the experimental analysis of functionally graded material using laser metal deposition process.

  9. Functionally Graded Material: An overview

    CSIR Research Space (South Africa)

    Mahamood, RM

    2012-07-01

    Full Text Available Functionally Graded Material (FGM) belongs to a class of advanced material characterized by variation in properties as the dimension varies. The overall properties of FMG are unique and different from any of the individual material that forms it...

  10. Controlling Weapons-Grade Fissile Material

    Science.gov (United States)

    Rotblat, J.

    1977-01-01

    Discusses the problems of controlling weapons-grade fissionable material. Projections of the growth of fission nuclear reactors indicates sufficient materials will be available to construct 300,000 atomic bombs each containing 10 kilograms of plutonium by 1990. (SL)

  11. Thermal rectification in graded materials.

    Science.gov (United States)

    Wang, Jiao; Pereira, Emmanuel; Casati, Giulio

    2012-07-01

    In order to identify the basic conditions for thermal rectification we investigate a simple model with nonuniform, graded mass distribution. The existence of thermal rectification is theoretically predicted and numerically confirmed, suggesting that thermal rectification is a typical occurrence in graded systems, which are likely to be natural candidates for the actual fabrication of thermal diodes. In view of practical implications, the dependence of rectification on the asymmetry and system's size is studied.

  12. The Effect of the Involvement within Career Academies by Elective Participation of Eleventh and Twelfth Grade High School Students during the Implementation Year

    Science.gov (United States)

    Johnston, Nancy A.

    2010-01-01

    The purpose of this study was to determine the effect of elective participation in one of three implementation year Career Academies, Education, Entrepreneurship, or Finance, on upper-class high school academic grades, Grade Point Average, and school academy participation measures. Significance of the junior and senior year of high school, the…

  13. An Investigation of the Perceptions of Students' Proficiency in Reading and Writing as Indicated by Twelfth Grade English Teachers and College English Composition Instructors

    Science.gov (United States)

    Charbonnet, Lara King

    2013-01-01

    The purpose of this study was to examine the differences in perceptions regarding students' proficiency in reading and writing skills between 12th grade English teachers and college English Composition instructors. A purposive, nonrandom sample of 12th grade English teachers and college English Composition instructors from West Tennessee were…

  14. Dental implants from functionally graded materials.

    Science.gov (United States)

    Mehrali, Mehdi; Shirazi, Farid Seyed; Mehrali, Mohammad; Metselaar, Hendrik Simon Cornelis; Kadri, Nahrizul Adib Bin; Osman, Noor Azuan Abu

    2013-10-01

    Functionally graded material (FGM) is a heterogeneous composite material including a number of constituents that exhibit a compositional gradient from one surface of the material to the other subsequently, resulting in a material with continuously varying properties in the thickness direction. FGMs are gaining attention for biomedical applications, especially for implants, owing to their reported superior composition. Dental implants can be functionally graded to create an optimized mechanical behavior and achieve the intended biocompatibility and osseointegration improvement. This review presents a comprehensive summary of biomaterials and manufacturing techniques researchers employ throughout the world. Generally, FGM and FGM porous biomaterials are more difficult to fabricate than uniform or homogenous biomaterials. Therefore, our discussion is intended to give the readers about successful and obstacles fabrication of FGM and porous FGM in dental implants that will bring state-of-the-art technology to the bedside and develop quality of life and present standards of care.

  15. Functionally graded materials produced by laser cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  16. Functionally graded materials with laser cladding

    NARCIS (Netherlands)

    de Hosson, J.T.M.; Pei, Y.T.; Brebbia, CA

    2001-01-01

    Al-40 w/o Si functionally graded materials (FGMs) were produced by a onestep laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surro

  17. Functionally graded materials produced by laser cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  18. Functionally Graded Materials Produced by Laser Cladding

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2000-01-01

    AlSi40 functionally graded materials (FGMs) were produced by a one-step laser cladding process on cast Al-alloy substrate as a possible solution for interfacial problems often present in laser coatings. The microstructure of the FGMs consists of a large amount of silicon primary particles surrounded

  19. Micromechanical models for graded composite materials

    DEFF Research Database (Denmark)

    Reiter, T; Dvorak, G.J.; Tvergaard, Viggo

    1997-01-01

    Elastic response of selected plane-array models of graded composite microstructures is examined under both uniform and linearly varying boundary tractions and displacements, by means of detailed finite element studies of large domains containing up to several thousand inclusions. Models consisting...... fields are predicted by Mori-Tanaka estimates. On the other hand, the response of graded materials with a skeletal microstructure in a wide transition zone between clearly defined matrix phases is better approximated by the self-consistent estimates. Certain exceptions are noted for loading by overall...

  20. Modeling Bamboo as a Functionally Graded Material

    Science.gov (United States)

    Silva, Emílio Carlos Nelli; Walters, Matthew C.; Paulino, Glaucio H.

    2008-02-01

    Natural fibers are promising for engineering applications due to their low cost. They are abundantly available in tropical and subtropical regions of the world, and they can be employed as construction materials. Among natural fibers, bamboo has been widely used for housing construction around the world. Bamboo is an optimized composite material which exploits the concept of Functionally Graded Material (FGM). Biological structures, such as bamboo, are composite materials that have complicated shapes and material distribution inside their domain, and thus the use of numerical methods such as the finite element method and multiscale methods such as homogenization, can help to further understanding of the mechanical behavior of these materials. The objective of this work is to explore techniques such as the finite element method and homogenization to investigate the structural behavior of bamboo. The finite element formulation uses graded finite elements to capture the varying material distribution through the bamboo wall. To observe bamboo behavior under applied loads, simulations are conducted considering a spatially-varying Young's modulus, an averaged Young's modulus, and orthotropic constitutive properties obtained from homogenization theory. The homogenization procedure uses effective, axisymmetric properties estimated from the spatially-varying bamboo composite. Three-dimensional models of bamboo cells were built and simulated under tension, torsion, and bending load cases.

  1. Photothermal characterization of functionally graded materials (FGM)

    Science.gov (United States)

    Jumel, J.; Terrien, N.; Arnould, O.; Krapez, J. C.; Lepoutre, F.

    2002-05-01

    This paper deals with the photothermal characterization of functionally graded materials (FGM) whose thermal properties are varying parallel to the sample surface. Simple experimental configurations and associated inversion procedures are proposed either for thermal mapping or for pitch-catch imaging mode. The photothermally induced periodic temperature field at the sample surface is first calculated using a specific code, then the inversion procedures are checked using a simulated set of data. Preliminary experimental results are presented outlining need of specific filter to cope with experimental noise.

  2. Probabilistic Modeling of Graded Timber Material Properties

    DEFF Research Database (Denmark)

    Faber, M. H.; Köhler, J.; Sørensen, John Dalsgaard

    2004-01-01

    The probabilistic modeling of timber material characteristics is considered with special emphasis to the modeling of the effect of different quality control and selection procedures used as means for quality grading in the production line. It is shown how statistical models may be established...... an important role in the overall probabilistic modeling. Therefore a scheme for estimating the parameters of probability distribution parameters focusing on the tail behavior has been established using a censored Maximum Likelihood estimation technique. The proposed probabilistic models have been formulated...

  3. Aeroelastic Tailoring of a Plate Wing with Functionally Graded Materials

    Science.gov (United States)

    Dunning, Peter D.; Stanford, Bret K.; Kim, H. Alicia; Jutte, Christine V.

    2014-01-01

    This work explores the use of functionally graded materials for the aeroelastic tailoring of a metallic cantilevered plate-like wing. Pareto trade-off curves between dynamic stability (flutter) and static aeroelastic stresses are obtained for a variety of grading strategies. A key comparison is between the effectiveness of material grading, geometric grading (i.e., plate thickness variations), and using both simultaneously. The introduction of material grading does, in some cases, improve the aeroelastic performance. This improvement, and the physical mechanism upon which it is based, depends on numerous factors: the two sets of metallic material parameters used for grading, the sweep of the plate, the aspect ratio of the plate, and whether the material is graded continuously or discretely.

  4. Metallic Functionally Graded Materials: A Specific Class of Advanced Composites

    Institute of Scientific and Technical Information of China (English)

    Jerzy J.Sobczak; Ludmil Drenchev

    2013-01-01

    Functionally graded materials,including their characterization,properties and production methods are a new rapidly developing field of materials science.The aims of this review are to systematize the basic production techniques for manufacturing functionally graded materials.Attention is paid to the principles for obtaining graded structure mainly in the metal based functionally graded materials.Several unpublished results obtained by the authors have been discussed briefly.Experimental methods and theoretical analysis for qualitative and quantitative estimation of graded properties have also been presented.The article can be useful for people who work in the field of functionally graded structures and materials,and who need a compact informative review of recent experimental and theoretical activity in this area.

  5. Asymptotic modelling of some functionally graded materials

    OpenAIRE

    Wozniak, Czeslaw; Wagrowska, Monika

    2010-01-01

    International audience; The object of analysis is a multilayered functionally graded laminated heat conductor. Region occupied by this heat conductor is denoted by Ω=(0, L)× Ξ, where Ξ is a region on the 0ξ1ξ2 plane and x∈(0, L). Region Ω is divided into n layers of the same thicknesses λ ...

  6. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Ocelik, V.; Pei, Y.T.; de Hosson, J.T.M.; Popoola, O; Dahotre, NB; Midea, SJ; Kopech, HM

    2003-01-01

    Two functionally graded coatings were prepared by different laser surface engineering techniques. Laser cladding of AlSi40 powder leads to the formation of functionally graded material (FGM) coating on AI-Si cast alloy substrate. Mapping of strain fields near the laser clad track using the digital i

  7. Africa South of the Sahara. Grade Twelve. [Resource Unit IV.] Project Social Studies.

    Science.gov (United States)

    Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

    This is the fourth of seven resource units for a twelfth grade course on value conflicts and policy decisions. The topic for this unit is Africa south of the Sahara. The objectives are listed as to generalizations, skills, and values. The double-page format relates objectives to pertinent content, teaching procedures, and instructional materials.…

  8. NONLINEAR BUCKLING CHARACTERISTIC OF GRADED MULTIWEB STRUCTURE OF HETEROGENEOUS MATERIALS

    Institute of Scientific and Technical Information of China (English)

    LI Yong; ZHANG Zhi-min

    2005-01-01

    The graded multiweb structure of heterogeneous anisotropic materials, which makes full use of the continuous, gradual and changing physical mechanical performance of material properties, has a widespread application in aeroplane aerofoil structure and automobile lightweight structure. On the basis of laminate buckling theory,the equivalent rigidity method is adopted to establish the corresponding constitutive relation and the non-linear buckling governing equation for the graded multiweb structure. In finding the solution, the critical load of buckling under different complicated boundary conditions together with combined loads were obtained and testification of the experimental analysis shows that the calculation results can satisfy the requirements of engineering design in a satisfactory way. Results obtained from the research say that: graded materials can reduce the concentrated stress on the interface in an effective way and weaken the effect of initial defect in materials and thereby improve the strength and toughness of materials.

  9. Ceramic/polymer functionally graded material (FGM) lightweight armor system

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, J.J.; McClellan, K.J.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

  10. Ceramic/polymer functionally graded material (FGM) lightweight armor system

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, J.J.; McClellan, K.J.

    1998-12-31

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and with liquid polymers at room temperature. Thus, they were able to demonstrate the feasibility of producing boron carbide-aluminum and boron carbide-polymer functionally graded materials.

  11. Designing functionally graded materials with superior load-bearing properties.

    Science.gov (United States)

    Zhang, Yu; Sun, Ming-Jie; Zhang, Denzil

    2012-03-01

    Ceramic prostheses often fail from fracture and wear. We hypothesize that these failures may be substantially mitigated by an appropriate grading of elastic modulus at the ceramic surface. In this study, we elucidate the effect of elastic modulus profile on the flexural damage resistance of functionally graded materials (FGMs), providing theoretical guidelines for designing FGMs with superior load-bearing property. The Young's modulus of the graded structure is assumed to vary in a power-law relation with a scaling exponent n; this is in accordance with experimental observations from our laboratory and elsewhere. Based on the theory for bending of graded beams, we examine the effect of n value and bulk-to-surface modulus ratio (E(b)/E(s)) on stress distribution through the graded layer. Theory predicts that a low exponent (0.15graded materials with various n values and E(b)/E(s) ratios can be fabricated by infiltrating alumina and zirconia with a low-modulus glass. Flexural tests show that graded alumina and zirconia with suitable values of these parameters exhibit superior load-bearing capacity, 20-50% higher than their homogeneous counterparts. Improving load-bearing capacity of ceramic materials could have broad impacts on biomedical, civil, structural, and an array of other engineering applications.

  12. Overview: Damage resistance of graded ceramic restorative materials.

    Science.gov (United States)

    Zhang, Yu

    2012-08-01

    Improving mechanical response of materials is of great interest in a wide range of disciplines, including biomechanics, tribology, geology, optoelectronics, and nanotechnology. It has been long recognized that spatial gradients in surface composition and structure can improve the mechanical integrity of a material. This review surveys recent results of sliding-contact, flexural, and fatigue tests on graded ceramic materials from our laboratories and elsewhere. Although our findings are examined in the context of possible applications for next-generation, graded all-ceramic dental restorations, implications of our studies have broad impact on biomedical, civil, structural, and an array of other engineering applications.

  13. Direct-write graded index materials realized in protein hydrogels

    Science.gov (United States)

    Kaehr, Bryan; Scrymgeour, David A.

    2016-09-01

    The ability to create optical materials with arbitrary index distributions would prove transformative for optics design and applications. However, current fabrication techniques for graded index (GRIN) materials rely on diffusion profiles and therefore are unable to realize arbitrary distribution GRIN design. Here, we demonstrate the laser direct writing of graded index structures in protein-based hydrogels using multiphoton lithography. We show index changes spanning a range of 10-2, which is comparable with laser densified glass and polymer systems. Further, we demonstrate the conversion of these written density variation structures into SiO2, opening up the possibility of transforming GRIN hydrogels to a wide range of material systems.

  14. Experimental Tape Casting of Adjacently Graded Materials for Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Bulatova, Regina

    graded thin films. The motivation to create such adjacently segmented structures stemmed from a search of material and a materials design alternative to the expensive rare earth element gadolinium which is widely used as a magnetic regenerator in the emerging magnetic refrigeration technology...

  15. Multi-Cultural Resource Center Materials Handbook, Grades K-3.

    Science.gov (United States)

    Gillespie, Mary F.; Barrientos, Anita

    This annotated bibliography cites multicultural materials whose themes correlate with basic concepts taught in the primary grades. The items are in the Multi-Cultural Resource Center of the Toledo, Ohio public schools. The purpose of the bibliography is to help teachers integrate materials into their classroom. Films, filmstrips, books, study…

  16. Higher-Order Theory for Functionally Graded Materials

    Science.gov (United States)

    Aboudi, J.; Pindera, M. J.; Arnold, Steven M.

    2001-01-01

    Functionally graded materials (FGM's) are a new generation of engineered materials wherein the microstructural details are spatially varied through nonuniform distribution of the reinforcement phase(s). Engineers accomplish this by using reinforcements with different properties, sizes, and shapes, as well as by interchanging the roles of the reinforcement and matrix phases in a continuous manner (ref. 1). The result is a microstructure that produces continuously or discretely changing thermal and mechanical properties at the macroscopic or continuum scale. This new concept of engineering the material's microstructure marks the beginning of a revolution both in the materials science and mechanics of materials areas since it allows one, for the first time, to fully integrate the material and structural considerations into the final design of structural components. Functionally graded materials are ideal candidates for applications involving severe thermal gradients, ranging from thermal structures in advanced aircraft and aerospace engines to computer circuit boards. Owing to the many variables that control the design of functionally graded microstructures, full exploitation of the FGM's potential requires the development of appropriate modeling strategies for their response to combined thermomechanical loads. Previously, most computational strategies for the response of FGM's did not explicitly couple the material's heterogeneous microstructure with the structural global analysis. Rather, local effective or macroscopic properties at a given point within the FGM were first obtained through homogenization based on a chosen micromechanics scheme and then subsequently used in a global thermomechanical analysis.

  17. Hybrid graded element model for transient heat conduction in functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    Lei-Lei Cao; Qing-Hua Qin; Ning Zhao

    2012-01-01

    This paper presents a hybrid graded element model for the transient heat conduction problem in functionally graded materials (FGMs).First,a Laplace transform approach is used to handle the time variable.Then,a fundamental solution in Laplace space for FGMs is constructed.Next,a hybrid graded element is formulated based on the obtained fundamental solution and a frame field.As a result,the graded properties of FGMs are naturally reflected by using the fundamental solution to interpolate the intra-element field.Further,Stefest's algorithm is employed to convert the results in Laplace space back into the time-space domain.Finally,the performance of the proposed method is assessed by several benchmark examples.The results demonstrate well the efficiency and accuracy of the proposed method.

  18. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    De Hosson, JTM; Pei, YT; Ocelik, [No Value; Sudarshan, TS; Stiglich, JJ; Jeandin, M

    2002-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-sitit microstructural observations during straining in an FEG-ESEM

  19. Functionally graded materials produced with high power lasers

    NARCIS (Netherlands)

    de Hosson, J.T.M.; Pei, Y.T.; Kumar, A; Chung, YW; Moore, JJ; Doll, GL; Yatsui, K; Misra, DS

    2002-01-01

    With a well-controlled laser melt injection (LMI) process, for the first time the feasibility is demonstrated to produce SiC particles (SiCp) reinforced Ti6Al4V functionally graded materials (FGMs). SiCp are injected just behind the laser beam into the extended part of the laser melt pool that is fo

  20. Functionally graded materials produced with high power lasers

    NARCIS (Netherlands)

    De Hosson, JTM; Ocelík, Vašek; Chandra, T; Torralba, JM; Sakai, T

    2003-01-01

    In this keynote paper two examples will be present of functionally graded materials produced with high power Nd:YAG lasers. In particular the conditions for a successful Laser Melt Injection (LMI) of SiC and WC particles into the melt pool of A18Si and Ti6Al4V alloys are presented. The formation of

  1. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    Pei, Y. T.; Ocelik, V.; De Hosson, J. T. M.

    2003-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-situ microstructural observations during straining in a field-emission

  2. Interfacial adhesion of laser clad functionally graded materials

    NARCIS (Netherlands)

    De Hosson, JTM; Pei, YT; Ocelik, [No Value; Sudarshan, TS; Stiglich, JJ; Jeandin, M

    2002-01-01

    Specially designed samples of laser clad AlSi40 functionally graded materials (FGM) are made for evaluating the interfacial adhesion. To obtain the interfacial bond strength notches are made right at the interface of the FGMs. In-sitit microstructural observations during straining in an FEG-ESEM (fi

  3. Fabrication and characteristics of alumina-iron functionally graded materials

    DEFF Research Database (Denmark)

    He, Zeming; Ma, J.; Tan, G.E.B.

    2009-01-01

    . The microstructure and the composition of the prepared component were studied, and its flexural strength, fracture toughness, and fracture energy were tested and evaluated. The relative density and the Vickers hardness of each layer in the graded material were also measured. The correlation between microstructure...

  4. Bibliography of Spanish Materials for Students, Grades Seven through Twelve.

    Science.gov (United States)

    California State Dept. of Education, Sacramento.

    This annotated bibliography of Spanish materials for students in grades seven through twelve is divided into the following categories: (1) Art, Drama, Music, and Poetry; (2) Books in Series; (3) Culture; (4) Dictionaries and Encyclopedias; (5) Literature; (6) Mathematics; (7) Physical Education, Health, and Recreation; (8) Reading and Language…

  5. Effective Dielectric Response of Composites with Graded Material

    Institute of Scientific and Technical Information of China (English)

    YANG Zi-Dong; WEI En-Bo; SONG Jin-Bao

    2004-01-01

    The effective dielectric response of linear composites containing graded material is investigated under an applied electric field Eo. For the cylindrical inclusion with gradient dielectric function, εi(r) = b+cr, randomly embedded in a host with dielectric constant εm, we have obtained the exact solution of local electric potential of the composite media regions, which obeys a linear constitutive relation D= εE, using hypergeometric function. In dilute limit, we have derived the effective dielectric response of the linear composite media. Furthermore, for larger volume fraction, the formulas of effective dielectric response of the graded composite media are given.

  6. Supersonic flutter analysis of thin cracked functionally graded material plates

    CERN Document Server

    Natarajan, S; Bordas, S

    2012-01-01

    In this paper, the flutter behaviour of simply supported square functionally graded material plates immersed in a supersonic flow is studied. An enriched 4-noded quadrilateral element based on field consistency approach is used for this study and the crack is modelled independent of the underlying mesh. The material properties are assumed to be temperature dependent and graded only in the thickness direction. The effective material properties are estimated using the rule of mixtures. The formulation is based on the first order shear deformation theory and the shear correction factors are evaluated employing the energy equivalence principle. The influence of the crack length, the crack orientation, the flow angle and the gradient index on the aerodynamic pressure and the frequency are numerically studied. The results obtained here reveal that the critical frequency and the critical pressure decreases with increase in crack length and it is minimum when the crack is aligned to the flow angle.

  7. Thermal Characterization of Functionally Graded Materials: Design of Optimum Experiments

    Science.gov (United States)

    Cole, Kevin D.

    2003-01-01

    This paper is a study of optimal experiment design applied to the measure of thermal properties in functionally graded materials. As a first step, a material with linearly-varying thermal properties is analyzed, and several different tran- sient experimental designs are discussed. An optimality criterion, based on sen- sitivity coefficients, is used to identify the best experimental design. Simulated experimental results are analyzed to verify that the identified best experiment design has the smallest errors in the estimated parameters. This procedure is general and can be applied to design of experiments for a variety of materials.

  8. Plasma spray forming of functionally graded materials mould

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zi-yu; FANG Jian-cheng; LI Hong-you

    2005-01-01

    A new technology of functionally graded materials(FGM) mould fabricated by plasma spraying and arc spraying was developed. According to applied characteristic of plastic mould, the reasonable coatings of FGM were designed and their microstructures were analyzed. At the same time, some key problems were solved including spray mould fabricating, FGM forming and demoulding, etc. The results show that the service performance of the FGM mould is much more excellent than the one composed of the traditional materials, and the life span can also be greatly increased. The technology will have a significant influence on materials development in mould industry.

  9. Love wave propagation in functionally graded piezoelectric material layer.

    Science.gov (United States)

    Du, Jianke; Jin, Xiaoying; Wang, Ji; Xian, Kai

    2007-03-01

    An exact approach is used to investigate Love waves in functionally graded piezoelectric material (FGPM) layer bonded to a semi-infinite homogeneous solid. The piezoelectric material is polarized in z-axis direction and the material properties change gradually with the thickness of the layer. We here assume that all material properties of the piezoelectric layer have the same exponential function distribution along the x-axis direction. The analytical solutions of dispersion relations are obtained for electrically open or short circuit conditions. The effects of the gradient variation of material constants on the phase velocity, the group velocity, and the coupled electromechanical factor are discussed in detail. The displacement, electric potential, and stress distributions along thickness of the graded layer are calculated and plotted. Numerical examples indicate that appropriate gradient distributing of the material properties make Love waves to propagate along the surface of the piezoelectric layer, or a bigger electromechanical coupling factor can be obtained, which is in favor of acquiring a better performance in surface acoustic wave (SAW) devices.

  10. Controlling Electromagnetic Field by Graded Meta-materials

    Science.gov (United States)

    Sun, Lei

    Metamaterials , i.e. artificial materials with electromagnetic properties not readily available in nature, have become a major research topic in both scientific and engineering communities. Being different from conventional materials, metamaterials possess peculiar electromagnetic properties, e.g. negative refractive index, depending on their structures. In particular, metamaterials form a basis for achieving cloaking device that makes an object invisible or transparency to the probing electromagnetic wave. This topic has significant impact on various fields ranging from optics, medicine, biology to nanotechnology. Several cloaking techniques have been proposed by different research groups, namely, anomalous localized resonance, transformation optics, and scattering cancellation, etc. Each of them has its own advantages and disadvantages. For instance, the limitation in working frequency is a primary disadvantage of them. This thesis is concentrated on controlling electromagnetic field by graded metamaterials, i.e, metamaterials with graded structures, with the objective to realize the broadband electromagnetic transparency by extending the working frequency. Regarding the limitations of existing cloaking techniques, we propose the graded model based on the scattering cancellation technique, because it does not rely on resonant phenomena, and is fairly robust to relatively high variations of the shape and electromagnetic properties of the cloaked object. We modify the original Mie theory and Rayleigh scattering theory to deal with the graded metamaterial structures, and calculate the scattering cross section of graded isotropic and anisotropic spherical structures, an alytically and numerically. For the graded isotropic spherical structure, we achieve the exact analytic expressions for both full-wave and Rayleigh scattering cross sections, within our modified Mie theory and Rayleigh scattering theory. The numerical studies on the scattering cross sections clearly

  11. Twelfth degree spline with application to quadrature.

    Science.gov (United States)

    Mohammed, P O; Hamasalh, F K

    2016-01-01

    In this paper existence and uniqueness of twelfth degree spline is proved with application to quadrature. This formula is in the class of splines of degree 12 and continuity order [Formula: see text] that matches the derivatives up to order 6 at the knots of a uniform partition. Some mistakes in the literature are pointed out and corrected. Numerical examples are given to illustrate the applicability and efficiency of the new method.

  12. THERMAL POST-BUCKLING OF FUNCTIONALLY GRADED MATERIAL TIMOSHENKO BEAMS

    Institute of Scientific and Technical Information of China (English)

    LI Shi-rong; ZHANG Jing-hua; ZHAO Yong-gang

    2006-01-01

    Analysis of thermal post-buckling of FGM (Functionally Graded Material)Timoshenko beams subjected to transversely non-uniform temperature rise is presented.By accurately considering the axial extension and transverse shear deformation in the sense of theory of Timoshenko beam, geometrical nonlinear governing equations including seven basic unknown functions for functionally graded beams subjected to mechanical and thermal loads were formulated. In the analysis, it was assumed that the material properties of the beam vary continuously as a power function of the thickness coordinate. By using a shooting method, the obtained nonlinear boundary value problem was numerically solved and thermal buckling and post-buckling response of transversely non-uniformly heated FGM Timoshenko beams with fixed-fixed edges were obtained. Characteristic curves of the buckling deformation of the beam varying with thermal load and the power law index are plotted. The effects of material gradient property on the buckling deformation and critical temperature of beam were discussed in details. The results show that there exists the tension-bend coupling deformation in the uniformly heated beam because of the transversely non-uniform characteristic of materials.

  13. Optimum Weight Design of Functionally Graded Material Gears

    Institute of Scientific and Technical Information of China (English)

    JING Shikai; ZHANG He; ZHOU Jingtao; SONG Guohua

    2015-01-01

    Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials (FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization (GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem.

  14. Japanese Language and Culture: 9-Year Program Classroom Assessment Materials, Grade 4

    Science.gov (United States)

    Alberta Education, 2008

    2008-01-01

    This document is designed to provide assessment materials for specific Grade 4 outcomes in the Japanese Language and Culture Nine-year Program, Grades 4-5-6. The assessment materials are designed for the beginner level in the context of teaching for communicative competence. Grade 4 learning outcomes from the Japanese Language and Culture…

  15. Method of lines for temperature field of functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    DAI Yao; SUN Qi; HAO Gui-xiang; YAN Xiu-fa; LI Yong-dong

    2005-01-01

    The finite element method (FEM) and the boundary element method (BEM) are often adopted. Howev er, they are not convenient to spatially vary thermal properties of functionally graded material (FGM). Therefore, the method of lines (MOL) is introduced to solve the temperature field of FGM. The basic idea of the method is to semi-discretize the governing equation into a system of ordinary differential equations (ODEs) defined on discrete lines by means of the finite difference method. The temperature field of FGM can be obtained by solving the ODEs. The functions of thermal properties are directly embodied in these equations and these properties are not discretized in the domain. Thus, difficulty of FEM and BEM is overcome by the method. As a numerical example, the temperature field of a plane problem is analyzed for FGMs through varying thermal conductivity coefficient by the MOL.

  16. Thermal post-bunkling analyses of functionally graded material rod

    Institute of Scientific and Technical Information of China (English)

    ZHAO Feng-qun; WANG Zhong-min; LIU Hong-zhao

    2007-01-01

    The non-linear governing differential equations of immovably simply supported functionally graded material (FGM) rod subjected to thermal loads were derived.The thermal post-buckling behaviors of FGM rod made of ZrO2 and Ti-6A1-4Vwere analyzed by shooting method. Firstly, the thermal post-buckling equilibrium paths of the FGM rod with different gradient index in the uniform temperature field were plotted,and compared with the behaviors of the homogeneous rods made of ZrO2 and Ti-6A1-4V materials, respectively. For given value of end rotation angles, the influence of gradient index on the thermal post-buckling behaviors of FGM rod was discussed. Secondly, the thermal post-buckling characteristics of the FGM rod were analyzed when the temperature difference parameter is changed while the bottom temperature parameter remains constant, and when the bottom temperature parameter is changed while the temperature difference parameter remains constant, and compared with the characteristics of the two homogeneous material rods.

  17. Synthesis of functionally graded materials via electrophoretic deposition and sintering

    Science.gov (United States)

    Wang, Xuan

    In this research, both the experiments and the modeling aspects of the net-shape fabrication of Functionally Graded Materials (FGM) by Electrophoretic Deposition (EPD) and consecutive sintering have been investigated. In order to obtain FGMs with desired final shape and properties, the issues regarding the shape evolution during sintering, the optimization of initial properties and composition profiles, and the fabrication of green components by EPD have been analyzed. In order to fabricate FGMs by the proposed technological sequence (EPD with the following sintering), the initial shape has to be optimized prior to sintering. In this research, the formulations to simulate sintering of an FGM were developed based on the continuum theory of sintering. A finite element sintering-modeling subroutine has been created and linked to the commercial finite element package ABAQUS. The shape changes of FGM disks during sintering were simulated. In order to obtain the desired final shape after sintering, an inverse modeling methodology was developed to optimize the initial shape. In order to fabricate the optimized initial shape of a green FGM specimen determined by the inverse continuum modeling of sintering, EPD of a number of FGMs was investigated. The FGM green specimens made of Al2O 3 and ZrO2 with the initial shape predicted by the inverse modeling, were deposited using self-designed equipments. The acetone-based suspension with n-butylamine as a particle-charging additive was used. The comparison of the shape between the sintered and the green FGM indicated that the developed experimental-theoretical methodology provided a reliable solution for near net shaping of complex 3-D FGM components. Other applications of EPD, such as in electronic packaging materials and zeolites, were also investigated. In order to fabricate functionally graded materials based on aligned porous structures, unidirectional freezing followed by freeze-drying and sintering has been investigated

  18. Dynamic fracture of functionally graded magnetoelectroelastic composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Stoynov, Y. [Faculty of Applied Mathematics and Informatics, Technical University of Sofia (Bulgaria); Dineva, P. [Institute of Mechanics, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2014-11-12

    The stress, magnetic and electric field analysis of multifunctional composites, weakened by impermeable cracks, is of fundamental importance for their structural integrity and reliable service performance. The aim is to study dynamic behavior of a plane of functionally graded magnetoelectroelastic composite with more than one crack. The coupled material properties vary exponentially in an arbitrary direction. The plane is subjected to anti-plane mechanical and in-plane electric and magnetic load. The boundary value problem described by the partial differential equations with variable coefficients is reduced to a non-hypersingular traction boundary integral equation based on the appropriate functional transform and frequency-dependent fundamental solution derived in a closed form by Radon transform. Software code based on the boundary integral equation method (BIEM) is developed, validated and inserted in numerical simulations. The obtained results show the sensitivity of the dynamic stress, magnetic and electric field concentration in the cracked plane to the type and characteristics of the dynamic load, to the location and cracks disposition, to the wave-crack-crack interactions and to the magnitude and direction of the material gradient.

  19. Bone remodeling induced by dental implants of functionally graded materials.

    Science.gov (United States)

    Lin, Daniel; Li, Qing; Li, Wei; Swain, Michael

    2010-02-01

    Functionally graded material (FGM) had been developed as a potential implant material to replace titanium for its improved capability of initial osseointegration. The idea behind FGM dental implant is that its properties can be tailored in accordance with the biomechanical needs at different regions adapting to its hosting bony tissues, therefore creating an improved overall integration and stability in the entire restoration. However, there have been very few reports available so far on predicting bone remodeling induced by FGM dental implants. This article aims to evaluate bone remodeling when replacing the titanium with a hydroxyapatite/collagen (HAP/Col) FGM model. A finite element model was constructed in the buccal-lingual section of a dental implant-bone structure generated from in vivo CT scan images. The remodeling simulation was performed over a 4 year healing period. Comparisons were made between the titanium implant and various FGM implants of this model. The FGM implants showed an improved bone remodeling outcome. The study is expected to provide a basis for future development of FGM implants.

  20. Fabrication of Mo-Ti functionally graded material

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Molybdenum alloys and titanium alloys were sintered at 1473K for 1 h under a pressure of 30 MPa. It was found that the addition of Al can increase evidently the relative density of sintered Mo-Fe alloys. The Fe-Al additives are also suitable for the sintering of titanium alloys, and the Mo alloy and Ti alloy can be densified concurrently with the same additives 3 % Fe-1.5 % Al. The experimental results also showed that during the sintering of Mo-Ti alloys the Fe-Al sintering aids promoted the formation of Mo-Ti solid solution, but the solid solution reaction occurred at the low sintering temperature of 1 473 K is inadequate. Finally, Mo-Ti system functionally graded material has been successfully fabricated. Its density changed gradually from 9.52 g/ cm3 to 4.48 g/cm3 in thickness direction. Such a material can be used in dynamic high-pressure technology.

  1. Twelfth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Rivera, J. (Stanford Geothermal Program)

    1987-01-22

    Preface The Twelfth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 20-22, 1987. The year ending December 1986 was very difficult for the domestic geothermal industry. Low oil prices caused a sharp drop in geothermal steam prices. We expected to see some effect upon attendance at the Twelfth Workshop. To our surprise, the attendance was up by thirteen from previous years, with one hundred and fifty-seven registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, Japan, Mexico, New Zealand, and Turkey. Despite a worldwide surplus of oil, international geothermal interest and development is growing at a remarkable pace. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Seven technical papers not presented at the Workshop are also published; they concern geothermal developments and research in Iceland, Italy, and New Zealand. In addition to these forty-eight technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was John R. Berg from the Department of Energy. We thank him for sharing with the Workshop participants his thoughts on the expectations of this agency in the role of alternative energy resources, specifically geothermal, within the country???s energy framework. His talk is represented as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: M. Gulati, K. Goyal, G.S. Bodvarsson, A.S. Batchelor, H. Dykstra, M.J. Reed, A. Truesdell, J.S. Gudmundsson, and J.R. Counsil. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank Jean Cook, Marilyn King, Amy Osugi, Terri Ramey, and Rosalee Benelli for their valued help with the meeting

  2. Twelfth Thermal and Fluids Analysis Workshop

    Science.gov (United States)

    Majumdar, Alok (Compiler)

    2002-01-01

    The Twelfth Thermal and Fluids Analysis Workshop (TFAWS 01) was held at the Bevill Center, The University of Alabama in Huntsville, Huntsville, Alabama, September 10-14, 2001. The theme for the hands-on training workshop and conference was "Engineering Excellence and Advances in the New Millenium." Forty-five technical papers were presented in four sessions: (1) Thermal Spacecraft/Payloads, (2) Thermal Propulsion/Vehicles, (3) Interdisciplinary Papers, and (4) Fluids Papers. Thirty-nine papers were published in these proceedings. The remaining six papers were not available in electronic format at the time of publication. In addition to the technical papers, there were (a) nine hands-on classes on thermal and flow analyses software, (b) thirteen short courses and product overview lectures, (c) five keynote lectures and, (d) panel discussions consisting of eight presentations. The workshop resulted in participation of 195 persons representing NASA Centers, Government agencies, aerospace industries, academia, software providers, and private corporations.

  3. misconceptions of twelfth grade students on selected chemistry ...

    African Journals Online (AJOL)

    Preferred Customer

    diagnostic tests in measuring students' misconceptions and performance in terms of ... to be mostly attributed to the type of the diagnostic methods employed in each study .... proportions of students' scores and misconceptions were computed in terms of each tier ... and in which homonuclear bond don't exist, its valence and.

  4. Fabrication and Microstructure of W/Cu Functionally Graded Material

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    W/Cu functionally gradient material (FGM) has excellent mech anical properties since it can effectively relax interlayer thermal st resses caused by the mismatch between their thermal expansion coeffici ents. W/Cu FGM combines the advantages of tungsten such as high meltin g point and service strength, with heat conductivity and plasticity of copper at room temperature. Thus it demonstrates satisfactory heat co rrosion and thermal shock resistance and will be a promising candidate as divertor component in thermonuclear device. Owing to the dramatic difference of melting point between tungsten and copper, conventional processes meet great difficulties in fabricating this kind of FGMs. A new approach termed graded sintering under ultra-high pressure (GSUHP) is proposed, with which a near 96% relative density of W/Cu FGM that contains a full distribution spectrum (0€?00%W) has been successfully fabricated. Suitable amount of transition metals (such as nickel, zir conium, vanadium) is employed as additives to activate tungsten's sint ering, enhance phase wettability and bonding strength between W and Cu . Densification effects of different layer of FGM were investigated. M icrostructure morphology and interface elements distribution were obse rved and analyzed. The thermal shock performance of W/Cu FGM was also preliminarily tested.

  5. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  6. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  7. “Textile Industry Twelfth Five Year Development Plan” issued

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Recently, the "Textile Industry Twelfth Five Year Development Plan" (hereinafter "Plan") has been issued by the Ministry of Industry and Information Technology, has been published to the public. The Plan highlights the restructuring, innovation, brand building

  8. Kinder Lernen Deutsch Materials Evaluation Project: Grades K-8.

    Science.gov (United States)

    American Association of Teachers of German.

    The Kinder Lernen Deutsch (Children Learn German) project, begun in 1987, is designed to promote German as a second language in grades K-8. The project is premised on the idea that the German program will contribute to the total development of the child and the child's personality. Included in this guide are a selection of recommended core…

  9. Three-dimensional Analysis of Functionally Graded Piezoelectric Plate with Arbitrarily Distributed Material Properties

    Institute of Scientific and Technical Information of China (English)

    LIU Wuxiang; MA Shaokun; WU Hao

    2014-01-01

    An orthotropic functionally graded piezoelectric rectangular plate with arbitrarily distributed material properties was studied, which is simply supported and grounded (electrically) on its four lateral edges. The state equations of the functionally graded piezoelectric material were obtained using the state-space approach, and a Peano-Baker series solution was obtained for the coupled electroelastic fields of the functionally graded piezoelectric plate subjected to mechanical and electric loading on its upper and lower surfaces. The influence of different distributions of material properties on the structural response of the plate was studied using the obtained solutions.

  10. Reducing Test Anxiety among 12th Grade Students: Iraqi Kurdistan Region/Soran City as an Example

    Science.gov (United States)

    Faqe, Chiayee Khorshid; Moheddin, Kurdistan Rafiq; Kakamad, Karwan Kakabra

    2016-01-01

    This study aims at reducing test anxiety among twelfth grade students at Soran city high schools. Throughout the study both quantitative and qualitative methods used to collect data. The participants were 450 twelfth grade students in five schools at Soran City-Kurdistan region of Iraq. Non-random purposive sampling because the students needed…

  11. Graded territories: Towards the design, specification and simulation of materially graded bending active structures

    DEFF Research Database (Denmark)

    Nicholas, Paul; Tamke, Martin; Ramsgaard Thomsen, Mette

    2012-01-01

    The ability to make materials with bespoke behavior affords new perspectives on incorporating material properties within the design process not available through natural materials. This paper reports the design and assembly of two bending-active, fibre-reinforced composite structures. Within...

  12. [Brief introduction of research methods of commodity specification and grade of Chinese medicinal materials].

    Science.gov (United States)

    Zhao, Hua-ye; Yan, Pei-pei; Yang, Wen-hua; Li, Chao-feng; Qi, Shu-ya; Li, Yan-qi; Cao, Jun-ling

    2015-02-01

    The commodity specification and grade of Chinese medicinal materials is a measure of the quality of traditional Chinese medicines (TCMs), which directly impacts on the safety and effectiveness of clinical medicines. It is an urgent problem to establish a set of standards which can both interpret the scientific connotation of the commodity specification and grade of Chinese medicinal materials and play a significant role on clinical medicines as well as markets. This paper reviews the research methods of the commodity specification and grade of Chinese medicinal materials such as sensory evaluation, chemical assessment, biological evaluation, and cited the applications of various methods for the classification of TCMs. It provides technical support for establishing standards of the commodity specification and grade of Chinese medicinal materials, and also constructs scientific basis for clinical rational drug use.

  13. Finite Element Analysis of Functionally Graded Material to Reduce Crazing in Transparent Armor

    Science.gov (United States)

    2015-09-01

    UNCLASSIFIED AD-E403 681 Technical Report ARMET-TR-14042 FINITE ELEMENT ANALYSIS OF FUNCTIONALLY GRADED MATERIAL TO REDUCE...prevent disclosure of its contents or reconstruction of the document. Do not return to the originator. UNCLASSIFIED REPORT DOCUMENTATION PAGE Form...September 2012 to April 2013 4. TITLE AND SUBTITLE FINITE ELEMENT ANALYSIS OF FUNCTIONALLY GRADED MATERIAL TO REDUCE CRAZING IN TRANSPARENT ARMOR

  14. Fundamental formulation for frictional contact with graded materials

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young’s modulus is assumed to vary in the form of E(y)=E0eαy and Poisson’s ratio is assumed to be constant. On the basis of the fundamental solutions, the singular integral equations are formulated for the unknown traction distributions with Green’s function method. From the fundamental integral equations, a series of integral equat...

  15. Effective dielectric response of graded composite materials containing anisotropic particles

    Institute of Scientific and Technical Information of China (English)

    Sang Zhi-Fang; Li Zhen-Ya

    2005-01-01

    The effective dielectric response of granular composites, in which spheroidal particles with graded shells are randomly distributed in a host matrix, is investigated. General expressions for the effective dielectric constant of the composites and partial resonant condition are obtained in the dilute limit by use of a quasi-static approximation. In particular, spheroidal particles with a power-law gradation profile in the shells are studied in detail. We find that, by adjusting the dielectric gradient profile in the shells, the shape and structure of particles, it is possible to enhance the effective dielectric constant of the composite and to realize partial resonance. Under the partial resonant conditions,the coated spheroidal particles with graded shells within the host matrix can be regarded as equivalent homogeneous spheroids embedded in the same host. The equivalent spheroids have the same dielectric constant as the original cores and semiaxes equal to those of the original shells: i.e., the partial resonant system behaves as if the cores of the particles were enlarged and the shells were absent.

  16. Optimal Experiment Design for Thermal Characterization of Functionally Graded Materials

    Science.gov (United States)

    Cole, Kevin D.

    2003-01-01

    The purpose of the project was to investigate methods to accurately verify that designed , materials meet thermal specifications. The project involved heat transfer calculations and optimization studies, and no laboratory experiments were performed. One part of the research involved study of materials in which conduction heat transfer predominates. Results include techniques to choose among several experimental designs, and protocols for determining the optimum experimental conditions for determination of thermal properties. Metal foam materials were also studied in which both conduction and radiation heat transfer are present. Results of this work include procedures to optimize the design of experiments to accurately measure both conductive and radiative thermal properties. Detailed results in the form of three journal papers have been appended to this report.

  17. Propagation of ultrasonic Love waves in nonhomogeneous elastic functionally graded materials.

    Science.gov (United States)

    Kiełczyński, P; Szalewski, M; Balcerzak, A; Wieja, K

    2016-02-01

    This paper presents a theoretical study of the propagation behavior of ultrasonic Love waves in nonhomogeneous functionally graded elastic materials, which is a vital problem in the mechanics of solids. The elastic properties (shear modulus) of a semi-infinite elastic half-space vary monotonically with the depth (distance from the surface of the material). The Direct Sturm-Liouville Problem that describes the propagation of Love waves in nonhomogeneous elastic functionally graded materials is formulated and solved by using two methods: i.e., (1) Finite Difference Method, and (2) Haskell-Thompson Transfer Matrix Method. The dispersion curves of phase and group velocity of surface Love waves in inhomogeneous elastic graded materials are evaluated. The integral formula for the group velocity of Love waves in nonhomogeneous elastic graded materials has been established. The effect of elastic non-homogeneities on the dispersion curves of Love waves is discussed. Two Love wave waveguide structures are analyzed: (1) a nonhomogeneous elastic surface layer deposited on a homogeneous elastic substrate, and (2) a semi-infinite nonhomogeneous elastic half-space. Obtained in this work, the phase and group velocity dispersion curves of Love waves propagating in the considered nonhomogeneous elastic waveguides have not previously been reported in the scientific literature. The results of this paper may give a deeper insight into the nature of Love waves propagation in elastic nonhomogeneous functionally graded materials, and can provide theoretical guidance for the design and optimization of Love wave based devices.

  18. Production of battery grade materials via an oxalate method

    Energy Technology Data Exchange (ETDEWEB)

    Belharouak, Ilias; Amine, Khalil

    2016-05-17

    An active electrode material for electrochemical devices such as lithium ion batteries includes a lithium transition metal oxide which is free of sodium and sulfur contaminants. The lithium transition metal oxide is prepared by calcining a mixture of a lithium precursor and a transition metal oxalate. Electrochemical devices use such active electrodes.

  19. Bibliography of Spanish Materials for Children: Kindergarten Through Grade Six.

    Science.gov (United States)

    Gonsalves, Julia, Comp.; And Others

    This annotated bibliography of instructional materials, intended for students, teachers, and native speakers of Spanish, contains more than 400 items emphasizing both language and culture. The entries are arranged alphabetically in sections including: (1) books in series; (2) children's literature; (3) dictionaries and encyclopedias; (4)…

  20. Alumina/Ce-Tzp Functionally Graded Materials by Electrophoretic Deposition

    Institute of Scientific and Technical Information of China (English)

    C.Zhao, J.Vleugels; O.Van Der Biest

    2000-01-01

    Cylindrical Al2O3/Ce-TZP functionally graded composites were fabricated by electrophoretic deposition and pressureless sintering in air. A continuous change in composition was realized by changing the composition of the suspension during deposition. In order to achieve full densification, a temperature above 1550℃ was necessary. The resultant FGM cylinder with a diameter of 5.6 mm shows the following structure: a central hole with a diameter less than 0.5 mm, a tough Ce-ZrO2 core with a diameter of about 3 mm, a gradient layer of about 1 mm, and a hard Al2O3-rich surface layer. The Ce-ZrO2 core has a Vickers hardness between 10and 11 GPa and an excellent toughness (>10 MPa√m). In the gradient layer, hardness and toughness vary continuously along the radius. The surface layer has a hardness of 15.5 GPa and a modest toughness of 2.5MPa√m.

  1. Calculation of the Composition Profile of a Functionally Graded Material Produced by Centrifugal Casting

    NARCIS (Netherlands)

    Biesheuvel, P. Maarten; Verweij, H.

    2000-01-01

    Functionally graded materials have designed inhomogeneous distributions of different components on the scale of the material. They can be made by suspension processing, in which particles are stacked in a controlled manner. Segregation effects can be used to obtain the required gradient if the parti

  2. Prediction of the adhesive behavior of bio-inspired functionally graded materials against rough surfaces

    Directory of Open Access Journals (Sweden)

    Chen Peijian

    2014-06-01

    Full Text Available Roughness effect and adhesion properties are important characteristics to be accessed in the development of functionally graded materials for biological and biomimetic applications, particularly for the hierarchical composition in biomimetic gecko robot. A multi-asperities adhesion model to predict the adhesive forces is presented in this work. The effect of surface roughness and graded material properties, which significantly alter the adhesive strength between contact bodies, can be simultaneously considered in the generalized model. It is found that proper interfacial strength can be controlled by adjusting surface roughness σ / R, graded exponent k and material parameter E*R / Δγ. The results should be helpful in the design of new biomimetic materials and useful in application of micro functional instruments.

  3. Surface Wave Speed of Functionally Graded Magneto-Electro-Elastic Materials with Initial Stresses

    Directory of Open Access Journals (Sweden)

    Li Li

    2014-09-01

    Full Text Available The shear surface wave at the free traction surface of half- infinite functionally graded magneto-electro-elastic material with initial stress is investigated. The material parameters are assumed to vary ex- ponentially along the thickness direction, only. The velocity equations of shear surface wave are derived on the electrically or magnetically open circuit and short circuit boundary conditions, based on the equations of motion of the graded magneto-electro-elastic material with the initial stresses and the free traction boundary conditions. The dispersive curves are obtained numerically and the influences of the initial stresses and the material gradient index on the dispersive curves are discussed. The investigation provides a basis for the development of new functionally graded magneto-electro-elastic surface wave devices.

  4. The grain grading model and prediction of deleterious porosity of cement-based materials

    Institute of Scientific and Technical Information of China (English)

    FENG Qi; LIU Jun-zhe

    2008-01-01

    The calculating model for the packing degree of spherical particles system was modified. The grain grading model of cement-based materials was established and could be applied in the global grading system as well as in the nano-fiber reinforced system. According to the grain grading model, two kinds of mortar were de-signed by using the global grain materials and nano-fiber materials such as fly ash, silica fume and NR powder.In this paper, the densities of two above systems cured for 90d were tested and the relationship of deleterious porosity and the total porosity of hardened mortar was discussed. Research results show that nano-fiber materialsuch as NR powder can increase the density of cement-based materials. The relationship of deleterious porosity and the total porosity of hardened mortar accords with logarithmic curve. The deleterious porosity and the ration-ality of the grading can be roughly predicted through calculating the packing degree by the grain grading model of cement-based materials.

  5. Fabrication of Al/Diamond Particles Functionally Graded Materials by Centrifugal Sintered-Casting Method

    Science.gov (United States)

    Watanabe, Yoshimi; Shibuya, Masafumi; Sato, Hisashi

    2013-03-01

    The continuous graded structure of functionally graded materials (FGMs) can be created under a centrifugal force. Centrifugal sintered-casting (CSC) method, proposed by the authors, is one of the fabrication methods of FGM under centrifugal force. This method is a combination of the centrifugal sintering method and centrifugal casting method. In this study, Al/diamond particle FGM was fabricated by the proposed method.

  6. Functionally Graded Materials by Laser Metal Deposition (PREPRINT)

    Science.gov (United States)

    2010-03-01

    A similar work carried out by Domack et al [14] showed macroscopic cracking in powder blends containing 40-60 percent Inconel 718 on Ti6Al4V...composition of Fe-82 wt% V (powder-1) and Inconel -625 (powder-2) powders are listed in Table 1. The substrate materials used for the experiment were cold...like laser power, travel speed and powder feed rate is yet to be determined to obtain a successful FGM. Inconel -625 deposits showed macro-cracks

  7. SUPER-THIN COATING MATERIAL FOR HIGH-GRADE HIGHWAY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the destroyed thin road surface, in which polymers and steel-fibers are added into ordinary concrete to form a steel fiber reinforced polymer-cement-based composite. the composite was successfully used to repair road surface. Microstructure and mechanical properties of the composites are measured and analyzed.

  8. Calculation of the Composition Profile of a Functionally Graded Material Produced by Co-sedimentation

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A sedimentation method is proposed to fabricate functionally graded materials (FGMs) with the continuous andsmooth variations of composition. The relations between the compositional distribution of deposited body and thepowder characteristics of raw materials as well as settling parameters are derived. Subsequently, the mathematicalmodel of forming FGM based on the co-sedimentation has been established. At last, numerical simulations areconducted to explore the effects of the particle sizes of raw materials and suspension height on the compositionaldistribution of final products.

  9. Understanding Thermal Transport in Graded, Layered and Hybrid Materials

    Science.gov (United States)

    2014-04-01

    Trindade B, Weißgärber T, Kieback B (2008) Mater Sci Eng A 475:39-44. 11 Schubert T, Ciupiński Ł, Zieliński W, Michalski A, Weißgärber T, Kieback B (2008...2011) 1097–1100. 14 Ł. Ciupiński, D. Siemiaszko, M. Rosiński, A. Michalski and K.J. Kurzydłowski, Advanced Materials Research Vol. 59 (2009) pp 120...Trindade B, Weißgärber T, Kieback B (2008) Mater Sci Eng A 475:39-44. 18 Schubert T, Ciupiński Ł, Zieliński W, Michalski A, Weißgärber T, Kieback B (2008

  10. Polymer composites filled with powders as polymer graded materials

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2010-11-01

    Full Text Available Purpose: The goal of this paper is to present general overview of research results on Polymeric Gradient Materials (PGMs performed in Division of Metallic and Polymeric Materials Processing of Silesian University of Technology. Achievements in research on production technologies, compositions and properties are presented.Design/methodology/approach: Two basic technologies that were used for preparing polymeric gradient composites filled with powders are presented (centrifugal and gravity casting. Composites based on epoxy resin and filled with iron, ferrite, graphite, coal powders are characterized. Among other, the following properties were tested: surface resistivity, coefficient of friction, magnetic induction, filler particles distribution in polymeric matrix and others.Findings: Casting methods presented in this article can successfully be used to produce polymer composites characterized by gradual distribution of powder content and by this way by gradual distribution of properties. Results show that it is possible not only to achieve but also in some extend to control gradient of filler concentration. Especially in centrifugal casting is possible to influence gradient of filler concentration and in this way gradient of many properties.Research limitations/implications: The main problem in presented researches was to introduce higher quantities of filler. The side effect of high filler content was high viscosity. Filler particles were added to the epoxy matrix in range from 3vol.% to 50vol.% depending on filler properties, method of casting etc.Practical implications: Elaborated PGMs may be applied in many fields such as medicine, electronics, mining industry, machine building industry and many others.Originality/value: New type of polymeric gradient composites were achieved using centrifugal and gravity casting technique. Influence of casting parameters, concentration and type of filler on composites properties was researched.

  11. Basic solution of two parallel Mode-I cracks in functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    LIANG Jun

    2008-01-01

    The solution of two parallel cracks in functionally graded materials subjected to a tensile stress loading is derived in this paper. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with coordinate parallel to the crack. The problem is formulated through Fourier transform into four pairs of dual integral equations, in which the unknown variables are jumps of displace- ments across crack surfaces. To solve the dual integral equations, the jumps of displacements across crack surfaces are directly expanded as s series of Jacobi polynomials to obtain the shielding effects of the two parallel cracks in functionally graded materials.

  12. Basic solution of two parallel Mode-I cracks in functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The solution of two parallel cracks in functionally graded materials subjected to a tensile stress loading is derived in this paper. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with coordinate parallel to the crack. The problem is formulated through Fourier transform into four pairs of dual integral equations, in which the unknown variables are jumps of displace-ments across crack surfaces. To solve the dual integral equations, the jumps of displacements across crack surfaces are directly expanded as a series of Jacobi polynomials to obtain the shielding effects of the two parallel cracks in functionally graded materials.

  13. Material and Thickness Grading for Aeroelastic Tailoring of the Common Research Model Wing Box

    Science.gov (United States)

    Stanford, Bret K.; Jutte, Christine V.

    2014-01-01

    This work quantifies the potential aeroelastic benefits of tailoring a full-scale wing box structure using tailored thickness distributions, material distributions, or both simultaneously. These tailoring schemes are considered for the wing skins, the spars, and the ribs. Material grading utilizes a spatially-continuous blend of two metals: Al and Al+SiC. Thicknesses and material fraction variables are specified at the 4 corners of the wing box, and a bilinear interpolation is used to compute these parameters for the interior of the planform. Pareto fronts detailing the conflict between static aeroelastic stresses and dynamic flutter boundaries are computed with a genetic algorithm. In some cases, a true material grading is found to be superior to a single-material structure.

  14. Generalized thermoelastic interaction in functional graded material with fractional order three-phase lag heat transfer

    Institute of Scientific and Technical Information of China (English)

    Ibrahim A. Abbas

    2015-01-01

    The present work is concerned with the solution of a problem on thermoelastic interactions in a functional graded material due to thermal shock in the context of the fractional order three-phase lag model. The governing equations of fractional order generalized thermoelasticity with three-phase lag model for functionally graded materials (FGM) (i.e., material with spatially varying material properties) are established. The analytical solution in the transform domain is obtained by using the eigenvalue approach. The inversion of Laplace transform is done numerically. The graphical results indicate that the fractional parameter has significant effects on all the physical quantities. Thus, we can consider the theory of fractional order generalized thermoelasticity an improvement on studying elastic materials.

  15. Chosen manufacture methods of Polymeric Graded Materials with electrical and magnetic properties gradation

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2012-10-01

    Full Text Available Purpose: The purpose of the paper is to present main results of Polymeric Graded Materials (PGMs investigations realized in Silesian University of Technology, Division of Metallic and Polymeric Materials Processing. Methods of PGMs manufacture with electrical and magnetic properties gradation are mainly discussed.Design/methodology/approach: In short introduction general remarks on functionally graded materials (FGMs and PGMs are presented. Next, methods used to prepare PGMs are presented together with physical basics determining composition, structure and properties gradation. Research methodology and chosen results showing PGMs structure and properties are also presented.Findings: Achieved results show that it is possible do design graded material structure and composition and to manufacture PGM that not precisely but in high extend meets designed requirements. The basic condition to accomplish this task is that physical basics of structure and composition gradient formation are known and relations between technological process parameters and ready material characteristics are properly applied.Research limitations/implications: Only chosen methods of PGMs manufacture are presented and only chosen PGMs characteristics are discussed.Practical implications: Presented technologies are widely used in industry to processing polymeric materials. Defined changes in parameters and properly designed composition will allow to utilize these technologies to PGMs manufacture. Ready parts with properties gradation may be applied in almost all industry branches. Few possible applications are presented in the text.Originality/value: New types of PGMs are described in the paper. Attention is paid mainly to materials with gradation of electrical and magnetic properties. The paper may be interesting for scientists involved in PGMs and for industry engineers looking for materials with electrical and magnetic properties gradation.Keywords: Multifunctional materials

  16. Tunable photonic band-gaps in one-dimensional photonic crystals containing linear graded index material

    Science.gov (United States)

    Singh, Bipin K.; Kumar, Pawan; Pandey, Praveen C.

    2014-12-01

    We have demonstrated control of the photonic band gaps (PBGs) in 1-D photonic crystals using linear graded index material. The analysis of PBG has been done in THz region by considering photonic crystals in the form of ten periods of second, third and fourth generation of the Fibonacci sequence as unit cell. The unit cells are constituted of two kinds of layers; one is taken of linear graded index material and other of normal dielectric material. For this investigation, we used a theoretical model based on transfer matrix method. We have obtained a large number of PBGs and their bandwidths can be tuned by changing the grading profile and thicknesses of linear graded index layers. The number of PBGs increases with increase in the thicknesses of layers and their bandwidths can be controlled by the contrast of initial and final refractive index of the graded layers. In this way, we provide more design freedom for photonic devices such as reflectors, filters, optical sensors, couplers, etc.

  17. Twelfth night of 1917 and the Moscow art theatre Twelfth night of 1917 and the Moscow art theatre

    Directory of Open Access Journals (Sweden)

    Arkady Ostrovsky

    2008-04-01

    Full Text Available On 15 September, 1917, in a letter to Nemirovich-Danchenko, Stanislavsky renounced the stage of the Moscow Art Theatre: I cannot think about any other roles, because I will never be able to do anything, at least in the Moscow Art Theatre. Maybe in some other area or some other place I will be able to rise. Of course I do not mean in other theatres, but in the studios. Othello — free!...1 After the tragedy Stanislavsky had endured with Selo Stepanchikovo, he threw himself into Studio work. He started rehearsing Twelfth Night, a play he had put on at the Society of Art and Literature in 1897. The Studio production of Twelfth Night was played on 25 December 1917, two months to the day after the Revolution. A few months later, Nikolai Efros published a book about the First Studio. It was dedicated to The Cricket on the Hearth but the words Efros used to describe the atmosphere in which Dickens’s production had opened were equally suitable for Twelfth Night: ‘You remember what sort of days those were? On 15 September, 1917, in a letter to Nemirovich-Danchenko, Stanislavsky renounced the stage of the Moscow Art Theatre: I cannot think about any other roles, because I will never be able to do anything, at least in the Moscow Art Theatre. Maybe in some other area or some other place I will be able to rise. Of course I do not mean in other theatres, but in the studios. Othello — free!...1 After the tragedy Stanislavsky had endured with Selo Stepanchikovo, he threw himself into Studio work. He started rehearsing Twelfth Night, a play he had put on at the Society of Art and Literature in 1897. The Studio production of Twelfth Night was played on 25 December 1917, two months to the day after the Revolution. A few months later, Nikolai Efros published a book about the First Studio. It was dedicated to The Cricket on the Hearth but the words Efros used to describe the atmosphere in which Dickens’s production had opened

  18. Keying Results on the CELT-Structure Test to U.S. Grade Level Instructional Materials

    Science.gov (United States)

    Moran, Ross T.

    1978-01-01

    It would be beneficial for ESL instructors to know the U.S. grade equivalent English ability of their students for placement purposes, especially if their instructional materials are keyed for U.S. classrooms. For this purpose, the Stanford Intermediate Level I Reading Comprehension Test was compared with the CELT-Structure Test. (Author/RM)

  19. Electromagnetic Spectrum. 7th and 8th Grade Agriculture Science Curriculum. Teacher Materials.

    Science.gov (United States)

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    This curriculum guide, the second in a set of six, contains teacher and student materials for a unit on the electromagnetic spectrum prepared as part of a seventh- and eighth-grade agricultural science curriculum that is integrated with science instruction. The guide contains the state goals and sample learning objectives for each goal for…

  20. SiCp/Ti6Al4V functionally graded materials produced by laser melt injection

    NARCIS (Netherlands)

    Pei, Y.T.; Ocelik, V.; Hosson, J.Th.M. De

    2002-01-01

    With a well-controlled laser melt injection (LMI) process, for the first time the feasibility is demonstrated to produce SiC particles (SiCp) reinforced Ti6Al4V functionally graded materials (FGMs). SiCp are injected just behind the laser beam into the extended part of the laser melt pool that is fo

  1. Functionally graded piezoelectric materials for modal transducers for exciting bulk and surface acoustic waves.

    Science.gov (United States)

    Yang, Jiashi; Jin, Zhihe; Li, Jiangyu

    2008-07-01

    We show that functionally graded piezoelectric materials can be used to make modal actuators through theoretical analyses of the excitation of extensional motion in an elastic rod and Rayleigh surface waves over an elastic half-plane. The results suggest alternatives with certain advantages for the excitation of bulk and surface acoustic waves.

  2. Five-Fold Branched Si Particles in Laser Clad AlSi Functionally Graded Materials

    NARCIS (Netherlands)

    Pei, Y.T.; Hosson, J.Th.M. De

    2001-01-01

    Many five-fold branched Si particles (Sip) were observed in Al–40 wt% Si functionally graded materials produced by a single-step laser cladding process on cast Al-alloy substrate. In this paper the five-fold twinning and growth features of Sip are scrutinized with orientation imaging microscopy and

  3. Damage tolerant functionally graded materials for advanced wear and friction applications

    Science.gov (United States)

    Prchlik, Lubos

    The research work presented in this dissertation focused on processing effects, microstructure development, characterization and performance evaluation of composite and graded coatings used for friction and wear control. The following issues were addressed. (1) Definition of prerequisites for a successful composite and graded coating formation by means of thermal spraying. (2) Improvement of characterization methods available for homogenous thermally sprayed coating and their extension to composite and graded materials. (3) Development of novel characterization methods specifically for FGMs, with a focus on through thickness property measurement by indentation and in-situ curvature techniques. (4) Design of composite materials with improved properties compared to homogenous coatings. (5) Fabrication and performance assessment of FGM with improved wear and impact damage properties. Materials. The materials studied included several material systems relevant to low friction and contact damage tolerant applications: MO-Mo2C, WC-Co cermets as materials commonly used sliding components of industrial machinery and NiCrAlY/8%-Yttria Partially Stabilized Zirconia composites as a potential solution for abradable sections of gas turbines and aircraft engines. In addition, uniform coatings such as molybdenum and Ni5%Al alloy were evaluated as model system to assess the influence of microstructure variation onto the mechanical property and wear response. Methods. The contact response of the materials was investigated through several techniques. These included methods evaluating the relevant intrinsic coating properties such as elastic modulus, residual stress, fracture toughness, scratch resistance and tests measuring the abrasion and friction-sliding behavior. Dry-sand and wet two-body abrasion testing was performed in addition to traditional ball on disc sliding tests. Among all characterization techniques the spherical indentation deserved most attention and enabled to

  4. Experiences with the characterization of new and ex-service grade 91 material

    Energy Technology Data Exchange (ETDEWEB)

    Bruycker, Evy de; Huysmans, Staf [Laborelec, Linkebeek (Belgium)

    2010-07-01

    Martensitic Grade 91 steel is intensively used for tubes and pipes as a replacement for Grade 22 and in the new ultra super critical power plants for components subject to temperatures up to 600 C. This relatively new material is more complex than its predecessors, as its high temperature strength depends on the precise distribution of fine precipitates. Hence small deviations in composition or heat treatment can have a significant influence on, for example, the creep strength. As the amount of available data on ex-service components in Grade 91 is still limited, a characterization of two ex-service materials and a comparison with new material was carried out. The chemical composition, microstructure, creep strength, mechanical properties and hardness of two new tubes, one new pipe, one ex-service tube and one ex-service pipe in Grade 91 were determined. For the determination of the creep strength the stress relaxation testing technique was used and compared with conventional creep tests on the same material. Stress relaxation testing proved to be an adequate technique to determine the current creep strength of Grade 91 material. A strong dependency of small deviations in composition on the creep strength was noted. A low carbon content seemed to decrease the creep strength significantly. The distribution of the precipitates was investigated with TEM for one new and one ex-service tube. The ex-service tube did show a slight coarsening of the M{sub 23}C{sub 6} compared to the new tube. However, the overall amount of precipitates (fine MX and M{sub 23}C{sub 6}) was larger for the ex-service tube, which had a higher amount of carbon. This could explain the higher creep strength of this tube. (orig.)

  5. Material Structure of a Graded Refractive Index Lens in Decapod Squid

    Science.gov (United States)

    Cai, Jing; Heiney, Paul; Sweeney, Alison

    2013-03-01

    Underwater vision with a camera-type eye that is simultaneously acute and sensitive requires a spherical lens with a graded distribution of refractive index. Squids have this type of lens, and our previous work has shown that its optical properties are likely achieved with radially variable densities of a single protein with multiple isoforms. Here we measure the spatial organization of this novel protein material in concentric layers of the lens and use these data to suggest possible mechanisms of self-assembly of the proteins into a graded refractive index structure. First, we performed small angle x-ray scattering (SAXS) to study how the protein is spatially organized. Then, molecular dynamic simulation allowed us to correlate structure to the possible dynamics of the system in different regions of the lens. The combination of simulation and SAXS data in this system revealed the likely protein-protein interactions, resulting material structure and its relationship to the observed and variable optical properties of this graded index system. We believe insights into the material properties of the squid lens system will inform the invention of self-assembling graded index devices.

  6. Analysis of polarization offsets observed for temperature-graded ferroelectric materials

    Science.gov (United States)

    Chen, Hui; Cheng, Taimin; Zheng, Hanlei; Zhang, Xinxin

    2016-04-01

    A transverse Ising model in the framework of the mean field approximation is developed to analyze the polarization offsets phenomena in temperature-graded ferroelectric materials. A function of two-spin exchange interaction strength has been introduced to describe the ferroelectric distortion due to the distribution of temperature gradients in materials. Comparisons of the computational results with the experimental data reveal some fundamental factors in the formation of polarization offsets. It is shown that ferroelectric distortion has influenced much on polarization offsets in temperature-graded ferroelectric materials. When quantum fluctuation effect as well as ferroelectric distortion is considered, we have successfully reproduced the experimental observations qualitatively, especially for the indistinguishable polarization offsets from the background at small temperature gradients, which were not successfully reproduced in prior theoretical studies.

  7. Functionally graded materials for orthopedic applications - an update on design and manufacturing.

    Science.gov (United States)

    Sola, Antonella; Bellucci, Devis; Cannillo, Valeria

    2016-01-01

    Functionally graded materials (FGMs) are innovative materials whose composition and/or microstructure gradually vary in space according to a designed law. As a result, also the properties gradually vary in space, so as to meet specific non-homogeneous service requirements without any abrupt interface at the macroscale. FGMs are emerging materials for orthopedic prostheses, since the functional gradient can be adapted to reproduce the local properties of the original bone, which helps to minimize the stress shielding effect and, at the same time, to reduce the shear stress between the implant and the surrounding bone tissue, two critical prerequisites for a longer lifespan of the graft. After a brief introduction to the origin of the FGM concept, the review surveys some representative examples of graded systems which are present in nature and, in particular, in the human body, with a focus on bone tissue. Then the rationale for using FGMs in orthopedic devices is discussed more in detail, taking into account both biological and biomechanical requirements. The core of the paper is dedicated to two fundamental topics, which are essential to benefit from the use of FGMs for orthopedic applications, namely (1) the computational tools for materials design and geometry optimization, and (2) the manufacturing techniques currently available to produce FGM-based grafts. This second part, in its turn, is structured to consider the production of functionally graded coatings (FGCs), of functionally graded 3D parts, and of special devices with a gradient in porosity (functionally graded scaffolds). The inspection of the literature on the argument clearly shows that the integration of design and manufacturing remains a critical step to overpass in order to achieve effective FGM-based implants.

  8. Ductile fracture toughness of modified A 302 grade B plate materials. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, D.E.; Manneschmidt, E.T.; Swain, R.L.

    1997-02-01

    The objective of this work was to develop ductile fracture toughness data in the form of J-R curves for modified A 302 grade B plate materials typical of those used in fabricating reactor pressure vessels. A previous experimental study at Materials Engineering Associates (MEA) on one particular heat of A 302 grade B plate showed decreasing J-R curves with increased specimen thickness. This characteristic has not been observed in numerous tests made on the more recent production materials of A 533 grade B and A 508 class 2 pressure vessel steels. It was unknown if the departure from norm for the MEA material was a generic characteristic for all heats of A 302 grade B steels or just unique to that one particular plate. Seven heats of modified A 302 grade B steel and one heat of vintage A 533 grade B steel were provided to this project by the General Electric Company of San Jose, California. All plates were tested for chemical content, tensile properties, Charpy transition temperature curves, drop-weight nil-ductility transition (NDT) temperature, and J-R curves. Tensile tests were made in the three principal orientations and at four temperatures, ranging from room temperature to 550{degrees}F (288{degrees}C). Charpy V-notch transition temperature curves were obtained in longitudinal, transverse, and short transverse orientations. J-R curves were made using four specimen sizes (1/2T, IT, 2T, and 4T). None of the seven heats of modified A 302 grade showed size effects of any consequence on the J-R curve behavior. Crack orientation effects were present, but none were severe enough to be reported as atypical. A test temperature increase from 180 to 550{degrees}F (82 to 288{degrees}C) produced the usual loss in J-R curve fracture toughness. Generic J-R curves and mathematical curve fits to the same were generated to represent each heat of material. This volume is a compilation of all data developed.

  9. Fracture analysis of a functionally graded interfacial zone between two dissimilar homogeneous materials

    Institute of Scientific and Technical Information of China (English)

    CHENG Zhanqi; ZHONG Zheng

    2006-01-01

    In this paper the plane elasticity problem for a functionally graded interfacial zone containing a crack between two dissimilar homogeneous materials has been considered. It is assumed that in the interfacial zone the reciprocal of the shear modulus is a linear function of the coordinate, while Possion's ratio keeps constant. By utilizing the Fourier transformation technique and the transfer matrix method, the mixed boundary problem is reduced to a system of singular integral equations that are solved numerically.The influences of the geometric parameters and the graded parameter on the stress intensity factors are investigated. The numerical results show that the graded parameters,the thickness of interfacial zone, the crack size and location have significant effects on the stress intensity factors.

  10. Fabrication of metal/metal functionally graded materials with a high melting point difference

    Institute of Scientific and Technical Information of China (English)

    Zhangjian Zhou; Changchun Ge

    2005-01-01

    Three kinds of full compositional distribution (from 0 to 100wt%W) W/Cu FGMs (functionally graded materials) with high density is fabricated by resistance sintering under ultra-high pressure. Microstructure analysis showed that the good grading composition of all FGMs has been obtained. The sintering mechanism of W is mainly solid state sintering. Thermal shock test in air demonstrated that the grading at the interface between W and Cu is effective for the reduction of thermal stress, but obvious transverse and vertical cracks occur in the pure W layer. The oxidation of the W60Cu40 layer and the W40Cu60 layer is heavier than that of the other layers.

  11. Fracture and fatigue analysis of functionally graded and homogeneous materials using singular integral equation approach

    Science.gov (United States)

    Zhao, Huaqing

    There are two major objectives of this thesis work. One is to study theoretically the fracture and fatigue behavior of both homogeneous and functionally graded materials, with or without crack bridging. The other is to further develop the singular integral equation approach in solving mixed boundary value problems. The newly developed functionally graded materials (FGMs) have attracted considerable research interests as candidate materials for structural applications ranging from aerospace to automobile to manufacturing. From the mechanics viewpoint, the unique feature of FGMs is that their resistance to deformation, fracture and damage varies spatially. In order to guide the microstructure selection and the design and performance assessment of components made of functionally graded materials, in this thesis work, a series of theoretical studies has been carried out on the mode I stress intensity factors and crack opening displacements for FGMs with different combinations of geometry and material under various loading conditions, including: (1) a functionally graded layer under uniform strain, far field pure bending and far field axial loading, (2) a functionally graded coating on an infinite substrate under uniform strain, and (3) a functionally graded coating on a finite substrate under uniform strain, far field pure bending and far field axial loading. In solving crack problems in homogeneous and non-homogeneous materials, a very powerful singular integral equation (SEE) method has been developed since 1960s by Erdogan and associates to solve mixed boundary value problems. However, some of the kernel functions developed earlier are incomplete and possibly erroneous. In this thesis work, mode I fracture problems in a homogeneous strip are reformulated and accurate singular Cauchy type kernels are derived. Very good convergence rates and consistency with standard data are achieved. Other kernel functions are subsequently developed for mode I fracture in

  12. Three-Dimensional Interfacial Green’s Function for Exponentially Graded Transversely Isotropic Bi-Materials

    Directory of Open Access Journals (Sweden)

    Farzad Akbari

    2016-06-01

    Full Text Available By virtue of a complete set of two displacement potentials, an analytical derivation of the elastostatic Green’s functions of an exponentially graded transversely isotropic bi-material full-space was presented. Three-dimensional point-load Green’s functions for stresses and displacements were given in line-integral representations. The formulation included a complete set of transformed stress-potential and displacement-potential relations, with the utilization of Fourier series and Hankel transform. As illustrations, the present Green’s functions were analytically degenerated into special cases, such as exponentially graded half-space and homogeneous full-space bi-material Green’s functions. Owing to the complicated integrand functions, the integrals were evaluated numerically, and in computing the integrals numerically, a robust and effective methodology was laid out which provided the necessary account of the presence of singularities of integration. Some typical numerical examples were also illustrated to demonstrate the general features of the exponentially graded bi-material Green’s functions which will be recognized by the effect of degree of variation of material properties.

  13. Determination of the Local Thermal Conductivity of Functionally Graded Materials by a Laser Flash Method

    DEFF Research Database (Denmark)

    Zajas, Jan Jakub; Heiselberg, Per

    2013-01-01

    Determination of thermal conductivity of construction materials is essential to estimate their insulation capabilities. In most cases, homogenous materials are used and well developed methods exist for measurements of their thermal conductivity. The task becomes more challenging when dealing with...... applied to create a map of thermal conductivity of a functionally graded material sample.......Determination of thermal conductivity of construction materials is essential to estimate their insulation capabilities. In most cases, homogenous materials are used and well developed methods exist for measurements of their thermal conductivity. The task becomes more challenging when dealing...... by scanning them point by point and determining the thermal conductivity as a function of the spatial dimensions. The method proves to be repeatable and of reasonable accuracy and can be used to determine the local thermal properties on a scale of millimeters. In this study, the method was successfully...

  14. 3D analytical solution for a rotating transversely isotropic annular plate of functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    CHEN Jiang-ying; CHEN Wei-qiu

    2007-01-01

    The analytical solution for an annular plate rotating at a constant angular velocity is derived by means of direct displacement method from the elasticity equations for axisymmetric problems of functionally graded transversely isotropic media.The displacement components are assumed as a linear combination of certain explicit functions of the radial coordinate, with seven undetermined coefficients being functions of the axial coordinate z. Seven equations governing these z-dependent functions are derived and solved by a progressive integrating scheme. The present solution can be degenerated into the solution of a rotating isotropic functionally graded annular plate. The solution also can be degenerated into that for transversely isotropic or isotropic homogeneous materials. Finally, a special case is considered and the effect of the material gradient index on the elastic field is illustrated numerically.

  15. CRACK PROPAGATING IN FUNCTIONALLY GRADED COATING WITH ARBITRARILY DISTRIBUTED MATERIAL PROPERTIES BONDED TO HOMOGENEOUS SUBSTRATE

    Institute of Scientific and Technical Information of China (English)

    Zhanqi Cheng; Danying Gao; Zheng Zhong

    2010-01-01

    In this paper,a finite crack with constant length(Yoffe type crack)propagating in a functionally graded coating with spatially varying elastic properties bonded to a homoge-neous substrate of finite thickness under anti-plane loading was studied.A multi-layered model is employed to model arbitrary variations of material properties based on two linearly-distributed material compliance parameters.The mixed boundary problem is reduced to a system of singular integral equations that are solved numerically.Some numerical examples are given to demonstrate the accuracy,efficiency and versatility of the model.The numerical results show that the graded parameters,the thicknesses of the interracial layer and the two homogeneous layers,the crack size and speed have significant effects on the dynamic fracture behavior.

  16. Pure bending of simply supported circular plate of transversely isotropic functionally graded material

    Institute of Scientific and Technical Information of China (English)

    LI Xiang-yu; DING Hao-jiang; CHEN Wei-qiu

    2006-01-01

    This paper considers the pure bending problem of simply supported transversely isotropic circular plates with elastic compliance coefficients being arbitrary functions of the thickness coordinate. First, the partial differential equation, which is satisfied by the stress functions for the axisymmetric deformation problem is derived. Then, stress functions are obtained by proper manipulation. The analytical expressions of axial force, bending moment and displacements are then deduced through integration.And then, stress functions are employed to solve problems of transversely isotropic functionally graded circular plate, with the integral constants completely determined from boundary conditions. An elasticity solution for pure bending problem, which coincides with the available solution when degenerated into the elasticity solutions for homogenous circular plate, is thus obtained.A numerical example is finally presented to show the effect of material inhomogeneity on the elastic field in a simply supported circular plate of transversely isotropic functionally graded material (FGM).

  17. Free-edge stress analysis of functionally graded material layered biocomposite laminates.

    Science.gov (United States)

    Huang, Bin; Kim, Heung Soo

    2014-10-01

    A stress function based theory is proposed to obtain free-edge stress distributions for three-dimensional, orthotropic, linearly elastic rectangular biocomposite laminates with surface-bonded functionally graded materials (FGM). The assumed stress fields automatically satisfy the pointwise equilibrium equation, as well as traction-free and free edge boundary conditions. The complementary virtual work principle, followed by the general eigenvalue solution procedure, is used to obtain 3-D free edge stress states. A typical stacking sequence of composite laminate is used as numerical investigation with surface bonded FGMs. It is shown that with proper exponential factor of FGMs, the interlaminar stresses at the FGM layer interface can be reduced significantly, in return to prevent debonding of FGM layers. This approach can be useful in the design of functionally graded material layered biocomposite structures.

  18. Preparation of Al/Si functionally graded materials using ultrasonic separation method

    Directory of Open Access Journals (Sweden)

    Zhang Zhongtao

    2008-08-01

    Full Text Available Functionally graded materials (FGM have been widely used in many industries such as aerospace, energy and electronics. In this experimental study of fabricating FGM, an approach was developed to prepare Al/Si FGM using power ultrasonic separation method. Material sample with continuously changing composition and performance/properties was successfully produced. Results showed that the microstructure of the FGM sample transited, from its top to bottom, from the hypereutectic structure with a large quantity of primary Si gradually to the eutectic, and fi nally to the hypoeutectic with numerous primary Al dendrites. The distribution of primary Si and microhardness of the FGM sample also presented graded characteristics, resulting that the wear resistance of the FGM sample decreased from top to bottom. Preliminary discussion was made on the mechanism of the formation of Al/Si FGM.

  19. Preparation of Al/Si functionally graded materials using ultrasonic separation method

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhongtao; LI Tingju; Yue Hongyun; Zhang Jian; Li Jie

    2008-01-01

    Functionally graded materials (FGM) have been widely used in many industries such as aerospace, energy and electronics. In this experimental study of fabricating FGM, an approach was developed to prepare Al/Si FGM using power ultrasonic separation method. Material sample with continuously changing composition and performance/properties was successfully produced. Results showed that the microstructure of the FGM sample transited, from its top to bottom, from the hypereutectic structure with a large quantity of primary Si gradually to the eutectic, and finally to the hypoeutectic with numerous primary AI dendrites. The distribution of primary Si and microhardness of the FGM sample also presented graded characteristics, resulting that the wear resistance of the FGM sample decreased from top to bottom. Preliminary discussion was made on the mechanism of the formation of Al/Si FGM.

  20. Stresses and Displacements in Functionally Graded Materials of Semi-Infinite Extent Induced by Rectangular Loadings

    Directory of Open Access Journals (Sweden)

    Zhong-Qi Yue

    2012-01-01

    Full Text Available This paper presents the stress and displacement fields in a functionally graded material (FGM caused by a load. The FGM is a graded material of Si3N4-based ceramics and is assumed to be of semi-infinite extent. The load is a distributed loading over a rectangular area that is parallel to the external surface of the FGM and either on its external surface or within its interior space. The point-load analytical solutions or so-called Yue’s solutions are used for the numerical integration over the distributed loaded area. The loaded area is discretized into 200 small equal-sized rectangular elements. The numerical integration is carried out with the regular Gaussian quadrature. Weak and strong singular integrations encountered when the field points are located on the loaded plane, are resolved with the classical methods in boundary element analysis. The numerical integration results have high accuracy.

  1. Sound radiation of a functionally graded material cylindrical shell in water by mobility method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Based on the fundamental dynamic equations of functionally graded material (FGM) cylindrical shell, this paper investigates the sound radiation of vibrational FGM shell in water by mobility method. This model takes into account the exterior fluid loading due to the sound press radiated by the FGM shell. The FGM cylindrical shell was excited by a harmonic line radial force uniformly distributing along the generator. The FGM shell equations of motion, the Helmholtz equation in the exterior fluid medium and th...

  2. A theoretical study of the propagation of Rayleigh waves in a functionally graded piezoelectric material (FGPM).

    Science.gov (United States)

    Ben Salah, Issam; Njeh, Anouar; Ben Ghozlen, Mohamed Hédi

    2012-02-01

    An exact approach is used to investigate Rayleigh waves in a functionally graded piezoelectric material (FGPM) layer bonded to a semi infinite homogenous solid. The piezoelectric material is polarized when the six fold symmetry axis is put along the propagation direction x(1). The FGPM character imposes that the material properties change gradually with the thickness of the layer. Contrary to the analytical approach, the adopted numerical methods, including the ordinary differential equation (ODE) and the stiffness matrix method (SMM), treat separately the electrical and mechanical gradients. The influences of graded variations applied to FGPM film coefficients on the dispersion curves of Rayleigh waves are discussed. The effects of gradient coefficients on electromechanical coupling factor, displacement fields, stress distributions and electrical potential, are reported. The obtained deviations in comparison with the ungraded homogenous film are plotted with respect to the dimensionless wavenumber. Opposite effects are observed on the coupling factor when graded variations are applied separately. A particular attention has been devoted to the maximum of the coupling factor and it dependence on the stratification rate and the gradient coefficient. This work provides with a theoretical foundation for the design and practical applications of SAW devices with high performance.

  3. A new design of cemented stem using functionally graded materials (FGM).

    Science.gov (United States)

    Hedia, H S; Aldousari, S M; Abdellatif, A K; Fouda, N

    2014-01-01

    One of the most frequent complications of total hip replacement (THR) is aseptic loosening of femoral component which is primarily due to changes of post-operative stress distribution pattern with respect to intact femur. Stress shielding of the femur is known to be a principal factor in aseptic loosening of hip replacements. Many designers show that a stiff stem shields the surrounding bone from mechanical loading causing stress shielding. Others show that reducing stem stiffness promotes higher proximal interface shear stress which increases the risk of proximal interface failure. Therefore, the task of this investigation is to solve these conflicting problems appeared in the cemented total hip replacement. The finite element method and optimization technique are used in order to find the optimal stem material which gives the optimal available stress distribution between the proximal medial femoral bone and the cement mantle interfaces. The stem is designed using the concept of functionally graded material (FGM) instead of using the conventional most common used stem material. The results showed that there are four feasible solutions from the optimization runs. The best of these designs is to use a cemented stem graded from titanium at the upper stem layer to collagen at the lower stem layer. This new cemented stem design completely eliminates the stress shielding problem at the proximal medial femoral region. The stress shielding using the cemented functionally graded stem is reduced by 98% compared to titanium stem.

  4. Twelfth annual US DOE low-level waste management conference

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The papers in this document comprise the proceedings of the Department of Energy's Twelfth Annual Low-Level Radioactive Waste Management Conference, which was held in Chicago, Illinois, on August 28 and 29, 1990. General subjects addressed during the conference included: mixed waste, low-level radioactive waste tracking and transportation, public involvement, performance assessment, waste stabilization, financial assurance, waste minimization, licensing and environmental documentation, below-regulatory-concern waste, low-level radioactive waste temporary storage, current challenges, and challenges beyond 1990.

  5. Twelfth cranial nerve involvement in Guillian Barre syndrome

    Directory of Open Access Journals (Sweden)

    Subrat Kumar Nanda

    2013-01-01

    Full Text Available Guillian Barre Syndrome (GBS is associated with cranial nerve involvement. Commonest cranial nerves involved were the facial and bulbar (IXth and Xth. Involvement of twelfth cranial nerve is rare in GBS. We present a case of GBS in a thirteen years old boy who developed severe tongue weakness and wasting at two weeks after the onset of GBS. The wasting and weakness of tongue improved at three months of follow up. Brief review of the literature about XIIth cranial nerve involvement in GBS is discussed.

  6. 78 FR 8684 - Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S

    Science.gov (United States)

    2013-02-06

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S AGENCY... RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is issuing this notice to advise the public of the twelfth meeting of the RTCA Special Committee 222, Inmarsat AMS(R)S. DATES: The...

  7. Twelfth nerve paresis induced by an unusual posterior fossa arachnoid cyst: case report and literature review.

    Science.gov (United States)

    Tarantino, Roberto; Marruzzo, Daniele; Colistra, Davide; Mancarella, Cristina; Delfini, Roberto

    2014-08-01

    There are only three cases of arachnoid cysts inducing twelfth nerve paresis described in English medical literature. We herein report one more instance. Six weeks after surgery, the patient has almost fully recovered. This case underlines the importance of considering the arachnoid cyst as a possible cause of twelfth nerve paresis.

  8. Static Response of Functionally Graded Material Plate under Transverse Load for Varying Aspect Ratio

    Directory of Open Access Journals (Sweden)

    Manish Bhandari

    2014-01-01

    Full Text Available Functionally gradient materials (FGM are one of the most widely used materials in various applications because of their adaptability to different situations by changing the material constituents as per the requirement. Nowadays it is very easy to tailor the properties to serve specific purposes in functionally gradient material. Most structural components used in the field of engineering can be classified as beams, plates, or shells for analysis purposes. In the present study the power law, sigmoid law and exponential distribution, is considered for the volume fraction distributions of the functionally graded plates. The work includes parametric studies performed by varying volume fraction distributions and aspect ratio. The FGM plate is subjected to transverse UDL (uniformly distributed load and point load and the response is analysed.

  9. An exact analysis of surface acoustic waves in a plate of functionally graded materials.

    Science.gov (United States)

    Gao, Liming; Wang, Ji; Zhong, Zheng; Du, Jianke

    2009-12-01

    Some traditional applications of structures and devices with homogeneous materials are being gradually replaced by functionally graded materials (FGM) with spatial variation of properties. The analysis of SAW propagating in FGM structures will be different primarily due to variations of material properties and resulting differential equations with variable coefficients. To provide an effective method and accurate results for the analysis of SAWs in FGM structures, we employed the Frobenius method as the only available method for a detailed analysis of SAW in materials with property variations in a linear pattern. Analytical examples are presented to demonstrate the effectiveness of the method and the effect of FGM on changes of surface displacements in SAW propagation.

  10. The nonlocal theory solution of a Mode-I crack in functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    LIANG Jun

    2009-01-01

    The behavior of a Mode-I finite crack in functionally graded materials is investigated using the non-local theory. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with coordinate vertical to the crack. The problem in this paper can be solved through the Fourier transform with the help of two pairs of dual integral equations, in which the unknown variables are jumps of displacements across crack surfaces. To solve dual integral equations, the jumps of displacements across crack surfaces are directly expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularities are present at crack tips. The non-local elastic solutions yield a finite stress at crack tips, thus allowing us to use the maximum stress as a fracture criterion. Numerical examples are provided to show the effects of the crack length, the parameter describing the functionally graded materials, the lattice parameter of materials and the materials constants upon the stress fields near crack tips.

  11. The nonlocal theory solution of a Mode-I crack in functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The behavior of a Mode-I finite crack in functionally graded materials is investigated using the non-local theory. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with coordinate vertical to the crack. The problem in this paper can be solved through the Fourier transform with the help of two pairs of dual integral equations, in which the unknown variables are jumps of dis- placements across crack surfaces. To solve dual integral equations, the jumps of displacements across crack surfaces are directly expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularities are present at crack tips. The non-local elastic solu- tions yield a finite stress at crack tips, thus allowing us to use the maximum stress as a fracture crite- rion. Numerical examples are provided to show the effects of the crack length, the parameter describ- ing the functionally graded materials, the lattice parameter of materials and the materials constants upon the stress fields near crack tips.

  12. Bleustein-Gulyaev waves in a functionally graded piezoelectric material layered structure

    Institute of Scientific and Technical Information of China (English)

    CAO Xiaoshan; JIN Feng; WANG ZiKun; LU TianJian

    2009-01-01

    This work presents a theoretical study of the propagation behavior of Bleustein-Gulyaev waves in a layered structure consisting of a functionally graded piezoelectric material (FGPM) layer and a trans-versely isotropic piezoelectric substrate. The influence of the graded variation of FGPM coefficients on the dispersion relations of Bleustein-Gulyaev waves in the layered structure is investigated. It is dem-onstrated that, for a certain frequency range of Bleustein-Gulyaev waves, the mechanical perturbations of the particles are restricted in the FPGM layer and the phase velocity is independent of the electrical boundary conditions at the free surface. Results presented in this study can not only provide further Insight on the electromechanical coupling behavior of surface waves in FGPM layered structures, but also lend a theoretical basis for the design of high-performance surface acoustic wave (SAW) devices.

  13. Bleustein-Gulyaev waves in a functionally graded piezoelectric material layered structure

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This work presents a theoretical study of the propagation behavior of Bleustein-Gulyaev waves in a layered structure consisting of a functionally graded piezoelectric material(FGPM) layer and a transversely isotropic piezoelectric substrate. The influence of the graded variation of FGPM coefficients on the dispersion relations of Bleustein-Gulyaev waves in the layered structure is investigated. It is demonstrated that,for a certain frequency range of Bleustein-Gulyaev waves,the mechanical perturbations of the particles are restricted in the FPGM layer and the phase velocity is independent of the electrical boundary conditions at the free surface. Results presented in this study can not only provide further insight on the electromechanical coupling behavior of surface waves in FGPM layered structures,but also lend a theoretical basis for the design of high-performance surface acoustic wave(SAW) devices.

  14. Optimization of Natural Frequencies and Sound Power of Beams Using Functionally Graded Material

    Directory of Open Access Journals (Sweden)

    Nabeel T. Alshabatat

    2014-01-01

    Full Text Available This paper presents a design method to optimize the material distribution of functionally graded beams with respect to some vibration and acoustic properties. The change of the material distribution through the beam length alters the stiffness and the mass of the beam. This can be used to alter a specific beam natural frequency. It can also be used to reduce the sound power radiated from the vibrating beam. Two novel volume fraction laws are used to describe the material volume distributions through the length of the FGM beam. The proposed method couples the finite element method (for the modal and harmonic analysis, Lumped Parameter Model (for calculating the power of sound radiation, and an optimization technique based on Genetic Algorithm. As a demonstration of this technique, the optimization procedure is applied to maximize the fundamental frequency of FGM cantilever and clamped beams and to minimize the sound radiation from vibrating clamped FGM beam at a specific frequency.

  15. Production of solar grade silicon in an arc furnace using high purity starting materials

    Science.gov (United States)

    Aulich, H. A.; Dietze, W.; Eisenbith, K.-H.; Schafer, J.; Schulze, F. W.; Urbach, H.-P.

    Solar cell-grade Si has been produced, using high purity SiO2 and C raw materials, by means of carbothermic reduction. The process involves the production of glass fibers from a melt of ordinary silica sand and glass-forming oxides, whose impurities are then leached out through treatment of the fibers with hot HCl. The high purity carbon is also prepared by treating carbon black with hot HCl. The purified SiO2 and C materials are reacted in an arc surface, yielding Si impurity concentrations corresponding to those of the highly purified materials. A three-phase, 550 kVA-arc furnace was constructed to prepare Si on a large scale.

  16. Analysis of macro and micro residual stresses in functionally graded materials by diffraction methods

    CERN Document Server

    Dantz, D; Reimers, W

    1999-01-01

    The residual stress state in microwave sintered metal-ceramic functionally graded materials (FGM) consisting of 8Y-ZrO/sub 2//Ni and 8Y-ZrO/sub 2//NiCr8020, respectively, was analysed by non- destructive diffraction methods. In $9 order to get knowledge of the complete residual stress state in the near surface region as well as in the interior of the material, complementary methods were applied. Whereas the surface was characterised by X-ray techniques using $9 conventional sources, the stresses within the bulk of the material were investigated by means of high energy synchrotron radiation. The stress state was found to obey the differences in the coefficients of thermal expansion $9 (micro-stresses) on the one hand and the inhomogeneous cooling conditions (macrostresses) on the other hand. (7 refs).

  17. Stress singularity in a top of composite wedge with internal functionally graded material

    Directory of Open Access Journals (Sweden)

    Victor V. Tikhomirov

    2015-10-01

    Full Text Available The antiplane problem of the composite wedge consisting of two homogeneous external wedge-shaped areas and an intermediate zone of the interphase is studied. The interphase material is assumed functionally graded. It is shown that the problem in each area is harmonic within the quadratic law of inhomogeneity of the material in the transverse direction. The influence of the interphase on the stress state at the top of the wedge is analyzed. As compared to the ideal contact of external materials, the presence of the interphase leads both to decrease and increase in the singularity exponent. Moreover, the stress asymptotic may have two singular terms for some values of the composite parameters.

  18. Evaluation of Fracture Parameters for Cracks in Coupled Thermoelasticity for Functionally Graded Materials

    Directory of Open Access Journals (Sweden)

    Repka M.

    2015-11-01

    Full Text Available The finite element method (FEM is developed for coupled thermoelastic crack problems if material properties are continuously varying. The weak form is utilized to derive the FEM equations. In conventional fracture theories the state of stress and strain at the crack tip vicinity is characterized by a single fracture parameter, namely the stress intensity factor or its equivalent, J-integral. In the present paper it is considered also the second fracture parameter called as the T-stress. For evaluation of both fracture parameters the quarter-point crack tip element is developed. Simple formulas for both fracture parameters are derived comparing the variation of displacements in the quarter-point element with asymptotic expression of displacement at the crack tip vicinity. The leading terms of the asymptotic expansions of fields in the crack-tip vicinity in a functionally graded material (FGM are the same as in a homogeneous one with material coefficients taken at the crack tip.

  19. Material and Geometric Nonlinear Analysis of Functionally Graded Plate-Shell Type Structures

    Science.gov (United States)

    Moita, J. S.; Araújo, A. L.; Mota Soares, C. M.; Mota Soares, C. A.; Herskovits, J.

    2016-08-01

    A nonlinear formulation for general Functionally Graded Material plate-shell type structures is presented. The formulation accounts for geometric and material nonlinear behaviour of these structures. Using the Newton-Raphson incremental-iterative method, the incremental equilibrium path is obtained, and in case of snap-through occurrence the automatic arc-length method is used. This simple and fast element model is a non-conforming triangular flat plate/shell element with 24 degrees of freedom for the generalized displacements. It is benchmarked in the solution of some illustrative plate- shell examples and the results are presented and discussed with numerical alternative models. Benchmark tests with material and geometrically nonlinear behaviour are also proposed.

  20. 2D crack problems in functionally graded magnet-electro-elastic materials

    Science.gov (United States)

    Stoynov, Yonko

    2016-12-01

    Magneto-electro-elastic composite materials have extensive application in modern smart structures, because they possess good coupling between mechanical, electrical and magnetic fields. This new effect was reported for the first time by Van Suchtelen [1] in 1972. Due to their ceramic structure cracks inevitably exists in these materials. In this study we consider functionally graded magneto-electro-elastic materials subjected to anti-plane time harmonic load. We use Boundary integral equation method (BIEM) to evaluate the dependence of stress concentration near the crack tip on the frequency of the applied external load. For complex crack configurations numerical calculations are tedious and need too much time. Here we present a new analytical approach that will significantly improve the numerical procedure for calculation of stress intensity factors (SIF).

  1. Thermal Buckling and Free Vibration Analysis of Heated Functionally Graded Material Beams

    Directory of Open Access Journals (Sweden)

    Khalane Sanjay Anandrao

    2013-05-01

    Full Text Available The effect of temperature dependency of material properties on thermal buckling and free vibration of functionally graded material (FGM beams is studied. The FGM beam is assumed to be at a uniform through thickness temperature, above the ambient temperature. Finite element system of equations based on the first order shear deformation theory is developed. FGM beam with axially immovable ends having the classical boundary conditions is analysed. An exhaustive set of numerical results, in terms of buckling temperatures and frequencies, is presented, considering the temperature independent and temperature dependent material properties. The buckling temperature and fundamental frequency obtained using the temperature independent material properties is higher than that obtained by using the temperature dependent material properties, for all the material distributions, geometrical parameters in terms of length to thickness ratios and the boundary conditions considered. It is also observed that the frequencies of the FGM beam will reduce with the increase in temperature. This observation is applicable for the higher modes of vibration also. The necessity of considering the temperature dependency of material properties in determining thermal buckling and vibration characteristics of FGM beams is clearly demonstrated.Defence Science Journal, 2013, 63(3, pp.315-322, DOI:http://dx.doi.org/10.14429/dsj.63.2370

  2. Natural frequencies of cracked functionally graded material plates by the extended finite element method

    CERN Document Server

    Natarajan, S; Bordas, S; Rabczuk, T; Kerfriden, P

    2011-01-01

    In this paper, the linear free flexural vibration of cracked functionally graded material plates is studied using the extended finite element method. A 4-noded quadrilateral plate bending element based on field and edge consistency requirement with 20 degrees of freedom per element is used for this study. The natural frequencies and mode shapes of simply supported and clamped square and rectangular plates are computed as a function of gradient index, crack length, crack orientation and crack location. The effect of thickness and influence of multiple cracks is also studied.

  3. Laser Rapid Manufacturing of Stainless Steel 316L/Inconel718 Functionally Graded Materials: Microstructure Evolution and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Dongjiang Wu

    2010-01-01

    Full Text Available Two patterns of functionally graded materials (FGMs were successfully fabricated whose compositions gradually varied from 100% stainless steel 316L to 100% Inconel718 superalloy using laser engineered net shaping process. The microstructure characterization, composition analysis, and microhardness along the graded direction were investigated. The comparison revealed the distinctions in solidification behavior, microstructure evolution of two patterns. In the end, the abrasive wear resistance of the material was investigated.

  4. Material properties of Grade 91 steel at elevated temperature and their comparison with a design code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeong Yeon; Kim, Woo Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Han Sang; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of)

    2013-10-15

    In this study, the material properties of tensile strength, creep properties, and creep crack growth model for Gr.91 steel at elevated temperature were obtained from material tests at KAERI, and the test data were compared with those of the French elevated temperature design code, RCC-MRx. The conservatism of the material properties in the French design code is highlighted. Mod.9Cr-1Mo (ASME Grade 91; Gr.91) steel is widely adopted as candidate material for Generation IV nuclear systems as well as for advanced thermal plants. In a Gen IV sodium-cooled fast reactor of the PGSFR (Prototype Gen IV Sodium-cooled Fast Reactor) being developed by KAERI (Korea Atomic Energy Research Institute), Gr.91 steel is selected as the material for the steam generator, secondary piping, and decay heat exchangers. However, as this material has a relatively shorter history of usage in an actual plant than austenitic stainless steel, there are still many issues to be addressed including the long-term creep rupture life extrapolation and ratcheting behavior with cyclic softening characteristics.

  5. SCATTERING OF THE HARMONIC STRESS WAVE BY CRACKS IN FUNCTIONALLY GRADED PIEZOELECTRIC MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Ma Li; Nie Wu; Wu Linzhi; Zhou Zhengong

    2005-01-01

    The present paper considers the scattering of the time harmonic stress wave by a single crack and two collinear cracks in functionally graded piezoelectric material (FGPM).It is assumed that the properties of the FGPM vary continuously as an exponential function.By using the Fourier transform and defining the jumps of displacements and electric potential components across the crack surface as the unknown functions, two pairs of dual integral equations are derived. To solve the dual integral equations, the jumps of the displacement and electric potential components across the crack surface are expanded in a series of Jacobi polynomials.Numerical examples are provided to show the influences of material properties on the dynamic stress and the electric displacement intensity factors.

  6. Transverse Vibration of Axially Moving Functionally Graded Materials Based on Timoshenko Beam Theory

    Directory of Open Access Journals (Sweden)

    Suihan Sui

    2015-01-01

    Full Text Available The transverse free vibration of an axially moving beam made of functionally graded materials (FGM is investigated using a Timoshenko beam theory. Natural frequencies, vibration modes, and critical speeds of such axially moving systems are determined and discussed in detail. The material properties are assumed to vary continuously through the thickness of the beam according to a power law distribution. Hamilton’s principle is employed to derive the governing equation and a complex mode approach is utilized to obtain the transverse dynamical behaviors including the vibration modes and natural frequencies. Effects of the axially moving speed and the power-law exponent on the dynamic responses are examined. Some numerical examples are presented to reveal the differences of natural frequencies for Timoshenko beam model and Euler beam model. Moreover, the critical speed is determined numerically to indicate its variation with respect to the power-law exponent, axial initial stress, and length to thickness ratio.

  7. Energy trapping of thickness-shear vibration modes of elastic plates with functionally graded materials.

    Science.gov (United States)

    Wang, Ji; Yang, Jiashi; Li, Jiangyu

    2007-03-01

    Energy trapping has important applications in the design of thickness-shear resonators. Considerable efforts have been made for the effective utilization and improvement of energy trapping with variations of plate configurations, such as adding electrodes and contouring. As a new approach in seeking improved energy trapping feature, we analyze thickness-shear vibrations in an elastic plate with functionally graded material (FGM) of in-plane variation of mechanical properties, such as elastic constants and density. A simple and general equation governing the thickness-shear modes is derived from a variational analysis. A plate with piecewise constant material properties is analyzed as an example. It is shown that such a plate can support thickness-shear vibration modes with obvious energy trapping. Bechmann's number for the existence of only one trapped mode also can be determined accordingly.

  8. Optimization of Sound Transmission Loss through a Thin Functionally Graded Material Cylindrical Shell

    Directory of Open Access Journals (Sweden)

    Ali Nouri

    2014-01-01

    Full Text Available The maximizing of sound transmission loss (TL across a functionally graded material (FGM cylindrical shell has been conducted using a genetic algorithm (GA. To prevent the softening effect from occurring due to optimization, the objective function is modified based on the first resonant frequency. Optimization is performed over the frequency range 1000–4000 Hz, where the ear is the most sensitive. The weighting constants are chosen here to correspond to an A-weighting scale. Since the weight of the shell structure is an important concern in most applications, the weight of the optimized structure is constrained. Several traditional materials are used and the result shows that optimized shells with aluminum-nickel and aluminum-steel FGM are the most effective at maximizing TL at both stiffness and mass control region, while they have minimum weight.

  9. Optimum gradient material for a functionally graded dental implant using metaheuristic algorithms.

    Science.gov (United States)

    Sadollah, Ali; Bahreininejad, Ardeshir

    2011-10-01

    Despite dental implantation being a great success, one of the key issues facing it is a mismatch of mechanical properties between engineered and native biomaterials, which makes osseointegration and bone remodeling problematical. Functionally graded material (FGM) has been proposed as a potential upgrade to some conventional implant materials such as titanium for selection in prosthetic dentistry. The idea of an FGM dental implant is that the property would vary in a certain pattern to match the biomechanical characteristics required at different regions in the hosting bone. However, matching the properties does not necessarily guarantee the best osseointegration and bone remodeling. Little existing research has been reported on developing an optimal design of an FGM dental implant for promoting long-term success. Based upon remodeling results, metaheuristic algorithms such as the genetic algorithms (GAs) and simulated annealing (SA) have been adopted to develop a multi-objective optimal design for FGM implantation design. The results are compared with those in literature.

  10. Enriched Element-Free Galerkin Method for Fracture Analysis of Functionally Graded Piezoelectric Materials

    Directory of Open Access Journals (Sweden)

    Guang Wei Meng

    2015-01-01

    Full Text Available A new method using the enriched element-free Galerkin method (EEFGM to model functionally graded piezoelectric materials (FGPMs with cracks was presented. To improve the solution accuracy, extended terms were introduced into the approximation function of the conventional element-free Galerkin method (EFGM to describe the displacement and electric fields near the crack. Compared with the conventional EFGM, the new approach requires smaller domain to describe the crack-tip singular field. Additionally, the domain of the nodes was not affected by the crack. Therefore, the visibility method and the diffraction method were no longer needed. The mechanical response of FGPM was discussed, when its material parameters changed exponentially in a certain direction. The modified J-integrals for FGPM were deduced, whose results were compared with the results of the conventional EFGM and the analytical solution. Numerical example results illustrated that this method is feasible and precise.

  11. Synthesis and Characterization of High Aluminum Zeolite X from Technical Grade Materials

    Directory of Open Access Journals (Sweden)

    Seyed Kamal Masoudian

    2013-06-01

    Full Text Available Zeolites are widely used as ion exchangers, adsorbents, separation materials and catalyst due to their well-tailored and highly-reproducible structures; therefore, the synthesis of zeolite from low grade resources can be interested. In the present work, high aluminum zeolite X was prepared from mixing technical grade sodium aluminate and sodium silicate solutions at temperatures between 70°C and 100°C. The synthesized zeolite X was characterized by SEM and X-ray methods according to ASTM standard procedures. The results showed that aging of the synthesis medium at the room temperature considerably increased the selectivity of zeolite X formation. On the other hand, high temperature of reaction mixture during crystallization formed zeolite A in the product; therefore, it decreased the purity of zeolite X. In addition, it was found that increasing H2O/Na2O and decreasing Na2O/SiO2 molar ratios in the reaction mixture resulted product with higher purity. © 2013 BCREC UNDIP. All rights reservedReceived: 7th January 2013; Revised: 7th April 2013; Accepted: 19th April 2013[How to Cite: Masoudian, S. K., Sadighi, S., Abbasi, A. (2013. Synthesis and Characterization of High Alu-minum Zeolite X from Technical Grade Materials. Bulletin of Chemical Reaction Engineering & Catalysis, 8 (1: 54-60. (doi:10.9767/bcrec.8.1.4321.54-60][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.8.1.4321.54-60] | View in  |

  12. Hygrothermal Fracture Analysis of Orthotropic Functionally Graded Materials Using Jk-Integral-Based Methods

    Directory of Open Access Journals (Sweden)

    Serra Topal

    2013-01-01

    Full Text Available This paper puts forward two different Jk-integral-based methods, which can be used to perform mixed-mode fracture analysis of orthotropic functionally graded materials subjected to hygrothermal stresses. The first method requires the evaluation of both components of Jk-integral, whereas the second method employs the first component J1 and the asymptotic crack tip displacement fields. Plane orthotropic hygrothermoelasticity is the basic theory behind the Jk-integral formulation, which is carried out by assuming that all material properties are functions of the spatial coordinates. Developed procedures are implemented by means of the finite element method and integrated into a general purpose finite element analysis software. Temperature and specific moisture concentration fields needed in the fracture analyses are also computed through finite element analysis. Each of the developed methods is utilized in conjunction with the superposition technique to calculate the hygrothermal fracture parameters. An inclined crack located in a hygrothermally loaded orthotropic functionally graded layer is examined in parametric analyses. Comparisons of the results generated by the proposed methods do indicate that both methods lead to numerical results of high accuracy and that the developed form of the Jk-integral is domain independent. Further results are presented so as to illustrate the influences of crack inclination angle, crack length, and crack location upon the modes I and II stress intensity factors.

  13. Design of new generation femoral prostheses using functionally graded materials: a finite element analysis.

    Science.gov (United States)

    Oshkour, A A; Abu Osman, N A; Yau, Y H; Tarlochan, F; Abas, W A B Wan

    2013-01-01

    This study aimed to develop a three-dimensional finite element model of a functionally graded femoral prosthesis. The model consisted of a femoral prosthesis created from functionally graded materials (FGMs), cement, and femur. The hip prosthesis was composed of FGMs made of titanium alloy, chrome-cobalt, and hydroxyapatite at volume fraction gradient exponents of 0, 1, and 5, respectively. The stress was measured on the femoral prosthesis, cement, and femur. Stress on the neck of the femoral prosthesis was not sensitive to the properties of the constituent material. However, stress on the stem and cement decreased proportionally as the volume fraction gradient exponent of the FGM increased. Meanwhile, stress became uniform on the cement mantle layer. In addition, stress on the femur in the proximal part increased and a high surface area of the femoral part was involved in absorbing the stress. As such, the stress-shielding area decreased. The results obtained in this study are significant in the design and longevity of new prosthetic devices because FGMs offer the potential to achieve stress distribution that more closely resembles that of the natural bone in the femur.

  14. Le mythe comme détour dans Twelfth Night The Myth as a Diversion in Twelfth Night

    Directory of Open Access Journals (Sweden)

    Cécile Mauré

    2009-06-01

    Full Text Available Being only rarely mentioned in the text, the myth might seem an anecdotal and trivial detail. The study of the myth of Echo and Narcissus in Twelfth Night shows us however that it is a decisive element in the reading and the understanding of the play. The references are numerous and often implicit. The characters themselves alternately play the roles of Echo and Narcissus. The play is structured as if it were a mirror in which the characters endlessly duplicate each other and echo their own words. Shakespeare plays with the different versions of the myth that he often blends with subtlety. For the sake of comedy, he dares to parody and demythologize Ovid’s story. The myth seems to divert our attention from the direction of the text but closer analysis suggests the reverse and invites us to find the meaning of the play which can be seen as a real labyrinth.

  15. A numerical study on the application of the functionally graded materials in the stent design.

    Science.gov (United States)

    Khosravi, Arezoo; Bahreinizad, Hossein; Bani, Milad Salimi; Karimi, Alireza

    2017-04-01

    Undesirable deformation of the stent can induce a significant amount of injure not only to the blood vessel but also to the plaque. The objective of this study was to reduce/minimize these undesirable deformations by the application of Functionally Graded Materials (FGM). To do this, Finite Element (FE) method was employed to simulate the expansion of a stent and the corresponding displacement of the stenosis plaque. Three hyperelastic plaque types as well as five elastoplastic stents were simulated. Dogboning, foreshortening, maximum stress in the plaque, and the pressure which is needed to fully expand the stent for different stent materials, were acquired. While all FGMs had lower dogboning in comparison to the stents made of the uniform materials, the stent with the lowest heterogeneous index displayed the lowest amount of dogboning. Steel stent showed the lowest foreshortening and fully expansion pressure but the difference was much lower than that the one for dogboning. Therefore, the FGM with the heterogeneous index of 0.5 is expected to exhibit the most suitable results. In addition, the results revealed that the material parameters has crucial effects on the deformation of the stent and, as a result, as a design point of view the FGM parameters can be tailored to achieve the goal of the biomechanical optimization.

  16. Thermoelastic buckling analysis of pre-twisted functionally graded beams with temperature-dependent material properties

    Science.gov (United States)

    Shenas, Amin Ghorbani; Malekzadeh, Parviz; Ziaee, Sima

    2017-04-01

    As a first endeavor, the thermal buckling behavior of pre-twisted functionally graded (FG) beams with temperature-dependent material properties is investigated. The governing stability equations are derived based on the third-order shear deformation theory (TSDT) in conjunction with the adjacent equilibrium state criterion under the von Kármán's nonlinear kinematic assumptions using the Chebyshev-Ritz method. The Chebyshev polynomials multiplied with some suitable boundary functions are used as the basis functions, which allow one to analyze the beams with different boundary conditions. The extracted system of nonlinear algebraic eigenvalue equations is solved iteratively to obtain the critical temperature rise. The convergence behavior together with accuracy of the solution method and the correctness of formulation are demonstrated through different examples. Then, the influences of the linear and nonlinear variation of the angle of twist along the beam axis, the value of twist angle, length-to-thickness ratio, thickness-to-width ratio, material gradient index and temperature dependence of material properties on the critical temperature rise of the pre-twisted FG beams under different boundary conditions are investigated. It is shown that the pre-twist angle increases the thermal buckling resistance of the pre-twisted FG beams, but the temperature dependence of material properties reduces it.

  17. Transverse vibration of pipe conveying fluid made of functionally graded materials using a symplectic method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhong-Min, E-mail: wangzhongm@xaut.edu.cn; Liu, Yan-Zhuang

    2016-03-15

    Highlights: • We investigate the transverse vibration of FGM pipe conveying fluid. • The FGM pipe conveying fluid can be classified into two cases. • The variations between the frequency and the power law exponent are obtained. • “Case 1” is relatively more reasonable than “case 2”. - Abstract: Problems related to the transverse vibration of pipe conveying fluid made of functionally graded material (FGM) are addressed. Based on inside and outside surface material compositions of the pipe, FGM pipe conveying fluid can be classified into two cases. It is hypothesized that the physical parameters of the material along the direction of the pipe wall thickness change in the simple power law. A differential equation of motion expressed in non-dimensional quantities is derived by using Hamilton's principle for systems of changing mass. Using the assuming modal method, the pipe deflection function is expanded into a series, in which each term is expressed to admissible function multiplied by generalized coordinate. Then, the differential equation of motion is discretized into the two order differential equations expressed in the generalized coordinates. Based on symplectic elastic theory and the introduction of dual system and dual variable, Hamilton's dual equations are derived, and the original problem is reduced to eigenvalue and eigenvector problem in the symplectic space. Finally, a symplectic method is employed to analyze the vibration and stability of FGM pipe conveying fluid. For a clamped–clamped FGM pipe conveying fluid in “case 1” and “case 2”, the dimensionless critical flow velocity for first-mode divergence and the critical coupled-mode flutter flow velocity are obtained, and the variations between the real part and imaginary part of dimensionless complex frequency and fluid velocity, mass ratio and the power law exponent (or graded index, volume fraction) for FGM pipe conveying fluid are analyzed.

  18. PREFACE: 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM 2012)

    Science.gov (United States)

    Zhou, Zhangjian; Li, Jingfeng; Zhang, Lianmeng; Ge, Changchun

    2013-03-01

    The 12th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials (FGM-2012) was held in Beijing, China, from 22-36 October 2012. This was part of a series of conferences organized every two years endorsed by International Advisory Committee for FGM's, which serves as a forum for scientists, educators, engineers and young students interested in the development of functionally graded materials (FGM). The series continues from the previous international symposium on FGM held in Sendai, Japan (1990), San Francisco, USA (1992), Lausanne, Switzerland (1994), Tsukuba, Japan (1996), Dresden, Germany (1998), Estes Park, USA (2000), Beijing, China (2002), Leuven, Belgium (2004), Hawaii, USA (2006), Sendai, Japan (2008) and Guimaraes, Portugal (2010). Functionally graded materials are non-uniform materials which are designed with embodied continuous spatial variations in composition and microstructure for the specific purpose of adjusting their thermal, structural, mechanical, biological or functional response to specific application conditions. Such multi-phase materials cover a range of space and time scales, and are best understood by means of a comprehensive multiscale, multiphysics approach. These kinds of materials are presently in the forefront of materials research, receiving worldwide attention. They have a broad range of applications including for example, biomedical, biomechanical, automotive, aerospace, mechanical, civil, nuclear, and naval engineering. New applications are continuously being discovered and developed. The objective of the FGM-2012 intends to provide opportunities for exchanging ideas and discussing state-of-the-art theories, techniques and applications in the fields of multiscale, multifunctional and FGM, through invited lectures, oral and poster presentations. FGM-2012 was organized and hosted by University of Science and Technology Beijing, China, together with Tsing-hua University and Wuhan University of

  19. Buckling Analysis of Functionally Graded Material Plates Using Higher Order Shear Deformation Theory

    Directory of Open Access Journals (Sweden)

    B. Sidda Reddy

    2013-01-01

    Full Text Available The prime aim of the present study is to present analytical formulations and solutions for the buckling analysis of simply supported functionally graded plates (FGPs using higher order shear deformation theory (HSDT without enforcing zero transverse shear stresses on the top and bottom surfaces of the plate. It does not require shear correction factors and transverse shear stresses vary parabolically across the thickness. Material properties of the plate are assumed to vary in the thickness direction according to a power law distribution in terms of the volume fractions of the constituents. The equations of motion and boundary conditions are derived using the principle of virtual work. Solutions are obtained for FGPs in closed-form using Navier’s technique. Comparison studies are performed to verify the validity of the present results from which it can be concluded that the proposed theory is accurate and efficient in predicting the buckling behavior of functionally graded plates. The effect of side-to-thickness ratio, aspect ratio, modulus ratio, the volume fraction exponent, and the loading conditions on the critical buckling load of FGPs is also investigated and discussed.

  20. Design and Synthesis of Ti-ZrO2 Functionally Graded Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Functionally graded materials (FGMs) based on titanium-zirconia system have been prepared by powder metallurgical method. The graded interlayer number and the compositional distribution have been designed by elastic finite element method. The interfacial microstructure between layers, the combining state of phases between Ti and ZrO2 have been investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy dispersive spectrometer) and so on. The co-existing region of Ti and ZrO2 has been determined by thermodynamic calculation to control the sintering atmosphere. The experimental results show that the joint between Ti and ZrO2 phases is physical in this composite and ZrO2 mainly exists as tetragonal phase. The microstructure of Ti-ZrO2 system FGM exhibits a transition from a zirconia particle dispersion in a titanium matrix to an inverse dispersion of titanium in zirconia. The gradient structure of titanium and zirconia can relieve thermal stress.

  1. Love waves in functionally graded piezoelectric materials by stiffness matrix method.

    Science.gov (United States)

    Ben Salah, Issam; Wali, Yassine; Ben Ghozlen, Mohamed Hédi

    2011-04-01

    A numerical matrix method relative to the propagation of ultrasonic guided waves in functionally graded piezoelectric heterostructure is given in order to make a comparative study with the respective performances of analytical methods proposed in literature. The preliminary obtained results show a good agreement, however numerical approach has the advantage of conceptual simplicity and flexibility brought about by the stiffness matrix method. The propagation behaviour of Love waves in a functionally graded piezoelectric material (FGPM) is investigated in this article. It involves a thin FGPM layer bonded perfectly to an elastic substrate. The inhomogeneous FGPM heterostructure has been stratified along the depth direction, hence each state can be considered as homogeneous and the ordinary differential equation method is applied. The obtained solutions are used to study the effect of an exponential gradient applied to physical properties. Such numerical approach allows applying different gradient variation for mechanical and electrical properties. For this case, the obtained results reveal opposite effects. The dispersive curves and phase velocities of the Love wave propagation in the layered piezoelectric film are obtained for electrical open and short cases on the free surface, respectively. The effect of gradient coefficients on coupled electromechanical factor, on the stress fields, the electrical potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the well known heterostructure PZT-5H/SiO(2), the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Love wave propagation behaviour.

  2. High Efficient Enrichment and Activated Dissolution of Refractory Low Grade Rh-containing Material

    Institute of Scientific and Technical Information of China (English)

    WU Xiaofeng; DONG Haigang; TONG Weifeng; ZHAO Jiachun; ZENG Rui

    2012-01-01

    Aiming to the low-grade rhodium-containing waste materials,a new process was proposed to enrich and activate rhodium by smelting using iron oxide as a trapping agent and activator.A rhodium concentrate was obtained by the separation of base metals and precious metals.The concentrate was reacted with dilute aqua regia to obtain rhodium solution.The factors influencing the enrichment and activation effects were discussed in this paper.The results showed that the dissolution rate is greater than 99% under the optimum conditions.In this process,the activation of rhodium was finished in the enrichment process.The iron oxide is both a trapping agent and activator,which simplifies the process and reduce the cost.

  3. Numerical simulation of thermal fracture in functionally graded materials using element-free Galerkin method

    Indian Academy of Sciences (India)

    SAHIL GARG; MOHIT PANT

    2017-03-01

    In the present work, element-free Galerkin method (EFGM) has been extended and implemented to simulate thermal fracture in functionally graded materials. The thermo-elastic fracture problem is decoupled into two separate parts. Initially, the temperature distribution over the domain is obtained by solving the heat transfer problem. The temperature field so obtained is then employed as input for the mechanical problem to determine the displacement and stress fields. The crack surfaces are modelled as non-insulated boundaries; hence the temperature field remains undisturbed by the presence of crack. A modified conservative M-integral technique has been used in order to extract the stress intensity factors for the simulated problems. The present analysisshows that the results obtained by EFGM are in good agreement with those available in the literature.

  4. Quantum cascade emission in the III-nitride material system designed with effective interface grading

    Energy Technology Data Exchange (ETDEWEB)

    Song, Alex Y., E-mail: alexys@stanford.edu; Huang, Tzu-Yung; Zah, Chung-En; Gmachl, Claire F. [Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08540 (United States); Bhat, Rajaram; Wang, Jie [Corning Incorporated, Corning, New York 14831 (United States); Allerman, Andrew A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2015-09-28

    We report the realization of quantum cascade (QC) light emission in the III-nitride material system, designed with effective interface grading (EIG). EIG induces a continuous transition between wells and barriers in the quantum confinement, which alters the eigenstate system and even delocalizes the states with higher energy. Fully transverse-magnetic spontaneous emission is observed from the fabricated III-nitride QC structure, with a center wavelength of ∼4.9 μm and a full width at half maximum of ∼110 meV, both in excellent agreement with theoretical predictions. A multi-peak photo-response spectrum is also measured from the QC structure, which again agrees well with theoretical calculations and verifies the effects of EIG.

  5. Quantum cascade emission in the III-nitride material system designed with effective interface grading

    Science.gov (United States)

    Song, Alex Y.; Bhat, Rajaram; Allerman, Andrew A.; Wang, Jie; Huang, Tzu-Yung; Zah, Chung-En; Gmachl, Claire F.

    2015-09-01

    We report the realization of quantum cascade (QC) light emission in the III-nitride material system, designed with effective interface grading (EIG). EIG induces a continuous transition between wells and barriers in the quantum confinement, which alters the eigenstate system and even delocalizes the states with higher energy. Fully transverse-magnetic spontaneous emission is observed from the fabricated III-nitride QC structure, with a center wavelength of ˜4.9 μm and a full width at half maximum of ˜110 meV, both in excellent agreement with theoretical predictions. A multi-peak photo-response spectrum is also measured from the QC structure, which again agrees well with theoretical calculations and verifies the effects of EIG.

  6. On the Effect of Functionally Graded Materials on Resonances of Rotating Beams

    Directory of Open Access Journals (Sweden)

    Arnaldo J. Mazzei Jr.

    2012-01-01

    Full Text Available Radially rotating beams attached to a rigid stem occur in several important engineering applications. Some examples include helicopter blades, turbine blades and certain aerospace applications. In most studies the beams have been treated as homogeneous. Here, with a goal of system improvement, non-homogeneous beams made of functionally graded materials are explored. The effects on the natural frequencies of the system are investigated. Euler-Bernoulli theory, including an axial stiffening effect and variations of both Young's modulus and density, is employed. An assumed mode approach is utilized, with the modes taken to be beam characteristic orthogonal polynomials. Results are obtained via Rayleigh-Ritz method and are compared for both the homogeneous and non-homogeneous cases. It was found, for example, that allowing Young's modulus and density to vary by approximately 2.15 and 1.15 times, respectively, leads to an increase of 23% in the lowest bending rotating natural frequency of the beam.

  7. Analysis of Unsteady Propagation of Mode Ⅲ Crack in Arbitrary Direction in Functionally Graded Materials

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Ho [Kyungpook National University, Daegu (Korea, Republic of); Cho, Sang Bong [Kyungnam University, Changwon (Korea, Republic of); Hawong, Jai Sug [Yeungnam University, Gyungsan (Korea, Republic of)

    2015-02-15

    The stress and displacement fields at the crack tip were studied during the unsteady propagation of a mode Ⅲ crack in a direction that was different from the property graduation direction in functionally graded materials (FGMs). The property graduation in FGMs was assumed based on the linearly varying shear modulus under a constant density and the exponentially varying shear modulus and density. To obtain the solution of the harmonic function, the general partial differential equation of the dynamic equilibrium equation was transformed into a Laplace equation. Based on the Laplace equation, the stress and displacement fields, which depended on the time rates of change in the crack tip speed and stress intensity factor, were obtained through an asymptotic analysis. Using the stress and displacement fields, the effects of the angled property variation on the stresses, displacements, and stress intensity factors are discussed.

  8. Influence of Inclusion Shape on Thermoelasto-Plastic Optimun Design of Ceramic Metal Functionally Graded Materials

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A nonlinear finite element method is applied to observe how inclusion shape influence the thermal response of a ceramic-metal functionally graded material (FGM).The elastic and plastic behaviors of the layers which are two-phase isotropic composites consisting of randomly oriented elastic spheroidal inclusions and a ductile matrix are predicted by a mean field method.The prediction results show that inclusion shape has remarkable influence on the overall behavior of the composite.The consequences of the thermal response analysis of the FGM are that the response is dependent on inclusion shape and its composition profile cooperatively and that the plastic behavior of each layer should be taken into account in optimum design of a ceramic-metal FGM.

  9. Bending and vibration of functionally graded material sandwich plates using an accurate theory

    CERN Document Server

    Natarajan, S

    2012-01-01

    In this paper, the bending and the free flexural vibration behaviour of sandwich functionally graded material (FGM) plates are investigated using QUAD-8 shear flexible element developed based on higher order structural theory. This theory accounts for the realistic variation of the displacements through the thickness. The governing equations obtained here are solved for static analysis considering two types of sandwich FGM plates, viz., homogeneous face sheets with FGM core and FGM face sheets with homogeneous hard core. The in-plane and rotary inertia terms are considered for vibration studies. The accuracy of the present formulation is tested considering the problems for which three-dimensional elasticity solutions are available. A detailed numerical study is carried out based on various higher-order models to examine the influence of the gradient index and the plate aspect ratio on the global/local response of different sandwich FGM plates.

  10. Geometrically Nonlinear Static Analysis of Edge Cracked Timoshenko Beams Composed of Functionally Graded Material

    Directory of Open Access Journals (Sweden)

    Şeref Doğuşcan Akbaş

    2013-01-01

    Full Text Available Geometrically nonlinear static analysis of edge cracked cantilever Timoshenko beams composed of functionally graded material (FGM subjected to a nonfollower transversal point load at the free end of the beam is studied with large displacements and large rotations. Material properties of the beam change in the height direction according to exponential distributions. The cracked beam is modeled as an assembly of two subbeams connected through a massless elastic rotational spring. In the study, the finite element of the beam is constructed by using the total Lagrangian Timoshenko beam element approximation. The nonlinear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The convergence study is performed for various numbers of finite elements. In the study, the effects of the location of crack, the depth of the crack, and various material distributions on the nonlinear static response of the FGM beam are investigated in detail. Also, the difference between the geometrically linear and nonlinear analysis of edge cracked FGM beam is investigated in detail.

  11. Design optimization of cementless metal-backed cup prostheses using the concept of functionally graded material

    Energy Technology Data Exchange (ETDEWEB)

    Hedia, H S; El-Midany, T T; Shabara, M A N; Fouda, N [Production Engineering and M/C Design Department, Faculty of Engineering, Mansoura University, Mansoura (Egypt)

    2006-09-15

    Metal backing has been widely used in acetabular cup design. A stiff backing for a polyethylene liner was initially believed to be mechanically favourable. Yet, recent studies of the load transfer around acetabular cups have shown that a stiff backing causes two problems. It generates higher stress peaks around the acetabular rim than those caused by full polyethylene cups and reduces the stresses transferred to the dome of the acetabulum causing stress shielding. The aim of this study is to overcome these two problems by improving the design of cementless metal-backed acetabular cups using the two-dimensional functionally graded material (FGM) concept through finite-element analysis and optimization techniques. It is found that the optimal 2D FGM model must have three bioactive materials of hydroxyapatite, Bioglass and collagen. This optimal material reduces the stress shielding at the dome of the acetabulum by 40% and 37% compared with stainless steel and titanium metal backing shells, respectively. In addition, using the 2D FGM model reduces the maximum interface shear stress in the bone by 31% compared to the titanium metal backing shell.

  12. Design optimization of cementless metal-backed cup prostheses using the concept of functionally graded material.

    Science.gov (United States)

    Hedia, H S; El-Midany, T T; Shabara, M A N; Fouda, N

    2006-09-01

    Metal backing has been widely used in acetabular cup design. A stiff backing for a polyethylene liner was initially believed to be mechanically favourable. Yet, recent studies of the load transfer around acetabular cups have shown that a stiff backing causes two problems. It generates higher stress peaks around the acetabular rim than those caused by full polyethylene cups and reduces the stresses transferred to the dome of the acetabulum causing stress shielding. The aim of this study is to overcome these two problems by improving the design of cementless metal-backed acetabular cups using the two-dimensional functionally graded material (FGM) concept through finite-element analysis and optimization techniques. It is found that the optimal 2D FGM model must have three bioactive materials of hydroxyapatite, Bioglass and collagen. This optimal material reduces the stress shielding at the dome of the acetabulum by 40% and 37% compared with stainless steel and titanium metal backing shells, respectively. In addition, using the 2D FGM model reduces the maximum interface shear stress in the bone by 31% compared to the titanium metal backing shell.

  13. An analysis of surface acoustic wave propagation in a plate of functionally graded materials with a layered model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In a homogeneous plate, Rayleigh waves will have a symmetric and anti-symmetric mode regarding to the mid-plane with different phase velocities. If plate properties vary along the thickness, or the plate is of functionally graded material (FGM), the symmetry of modes and frequency behavior will be modified, thus producing dif-ferent features for engineering applications such as amplifying or reducing the velocity and deformation. This kind of effect can also be easily realized by utilizing a layered structure with desired material properties that can produce these effects in terms of velocity and displacements, since Rayleigh waves in a solid with gen-eral material property grading schemes are difficult to analyze with known methods. Solutions from layered structures with exponential and polynomial property grad-ing schemes are obtained from the layered model and comparisons with known analytical results are made to validate the method and examine possible applica-tions of such structures in engineering.

  14. Improved design of cementless hip stems using two-dimensional functionally graded materials.

    Science.gov (United States)

    Hedia, H S; Shabara, M A N; El-Midany, T T; Fouda, N

    2006-10-01

    Increasingly, it is acknowledged that bone resorption around cementless hip implants may cause future problems. The solution is frequently sought in reducing implant stiffness. However, this confronts the designer with a true design conflict: how to reduce the stiffness without excessively loading the proximal bone/prosthesis interface? The aim of this work is to improve the design of cementless hip stem material, using two-dimensional (2D) functionally graded material (FGM) concept in order to solve the above problems. Two models were used in this analysis, using three materials with different elastic moduli, E(1), E(2), and E(3). In model I, the elastic moduli E(1) and E(2) gradually change along the upper stem surface, while E(3) is maintained constant along all the lower surface of the stem. However, in model II, the elastic moduli E(1) and E(2) gradually change along the lower stem surface, while E(3) is maintained constant all along the upper stem surface. It is found that the recommended model is model I, which has three distinct materials of hydroxyapatite, Bioglass, and collagen. The recommended design of 2D FGM is expected to reduce the stress shielding by 91% and 12%, respectively, compared with titanium stem and model II of FGM. It is found that this new design reduces the maximum interface shear stress at the lateral and medial sides of the femur by about 50%, compared with titanium stem. Furthermore, the maximum interface shear stress is reduced by about 17% and 11% at the lateral and medial sides of the femur, respectively, compared with that of model II of FGM.

  15. Twelfth International Symposium on Recent Advances in Environmental Health Research.

    Science.gov (United States)

    Tchounwou, Paul B

    2016-05-04

    During the past century, environmental hazards have become a major concern, not only to public health professionals, but also to the society at large because of their tremendous health, socio-cultural and economic impacts. Various anthropogenic or natural factors have been implicated in the alteration of ecosystem integrity, as well as in the development of a wide variety of acute and/or chronic diseases in humans. It has also been demonstrated that many environmental agents, acting either independently or in combination with other toxins, may induce a wide range of adverse health outcomes. Understanding the role played by the environment in the etiology of human diseases is critical to designing cost-effective control/prevention measures. This special issue of International Journal of Environmental Research and Public Health includes the proceedings of the Twelfth International Symposium on Recent Advances in Environmental Health Research. The Symposium provided an excellent opportunity to discuss the scientific advances in biomedical, environmental, and public health research that addresses global environmental health issues.

  16. Influence of Thermal Aging on Material Strength Behavior in Grade 91 Steel

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeong-Yeon; Kim, Woo-Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    In this study, the influence of thermal aging on yield strength and ductility for Grade 91 steel has been investigated. Service exposed Gr.91 steel materials sampled from a piping system of an ultra-supercritical plant over 73716 hours were used for material testing. The test results were compared with those of the virgin Gr.91 steel and those data were compared with RCC-MRx data. In this study, thermal aging effect of Gr.91 steel on the strength and ductility has been investigated. It was shown that yield strength has dropped as much as 35.8% over the service exposed duration of 8.4 years while ductility has been improved up to 23%. Since the present design rules of ASME Code and RCC-MRx do not provide concrete strength reduction factors for the thermal aging, it was shown to be necessary based on the findings of the present study to take this thermal aging influence into account in those design codes so that the design outcomes are to be more reliable.

  17. Analysis of Sigmoid Functionally Graded Material (S-FGM Nanoscale Plates Using the Nonlocal Elasticity Theory

    Directory of Open Access Journals (Sweden)

    Woo-Young Jung

    2013-01-01

    Full Text Available Based on a nonlocal elasticity theory, a model for sigmoid functionally graded material (S-FGM nanoscale plate with first-order shear deformation is studied. The material properties of S-FGM nanoscale plate are assumed to vary according to sigmoid function (two power law distribution of the volume fraction of the constituents. Elastic theory of the sigmoid FGM (S-FGM nanoscale plate is reformulated using the nonlocal differential constitutive relations of Eringen and first-order shear deformation theory. The equations of motion of the nonlocal theories are derived using Hamilton’s principle. The nonlocal elasticity of Eringen has the ability to capture the small scale effect. The solutions of S-FGM nanoscale plate are presented to illustrate the effect of nonlocal theory on bending and vibration response of the S-FGM nanoscale plates. The effects of nonlocal parameters, power law index, aspect ratio, elastic modulus ratio, side-to-thickness ratio, and loading type on bending and vibration response are investigated. Results of the present theory show a good agreement with the reference solutions. These results can be used for evaluating the reliability of size-dependent S-FGM nanoscale plate models developed in the future.

  18. Porosity-dependent nonlinear forced vibration analysis of functionally graded piezoelectric smart material plates

    Science.gov (United States)

    Qing Wang, Yan; Zu, Jean W.

    2017-10-01

    This work investigates the porosity-dependent nonlinear forced vibrations of functionally graded piezoelectric material (FGPM) plates by using both analytical and numerical methods. The FGPM plates contain porosities owing to the technical issues during the preparation of FGPMs. Two types of porosity distribution, namely, even and uneven distribution, are considered. A modified power law model is adopted to describe the material properties of the porous FGPM plates. Using D’Alembert’s principle, the out-of-plane equation of motion is derived by taking into account the Kármán nonlinear geometrical relations. After that, the Galerkin method is used to discretize the equation of motion, resulting in a set of ordinary differential equations with respect to time. These ordinary differential equations are solved analytically by employing the harmonic balance method. The approximate analytical results are verified by using the adaptive step-size fourth-order Runge–Kutta method. By means of the perturbation technique, the stability of approximate analytical solutions is examined. An interesting nonlinear broadband vibration phenomenon is detected in the FGPM plates with porosities. Nonlinear frequency-response characteristics of the present smart structures are investigated for various system parameters including the porosity type, the porosity volume fraction, the electric potential, the external excitation, the damping and the constituent volume fraction. It is found that these parameters have significant effects on the nonlinear vibration characteristics of porous FGPM plates.

  19. Lamb waves propagation in functionally graded piezoelectric materials by Peano-series method.

    Science.gov (United States)

    Ben Amor, Morched; Ben Ghozlen, Mohamed Hédi

    2015-01-01

    The Peano-series expansion is used to investigate the propagation of the lowest-order symmetric (S0) and antisymmetric (A0) Lamb wave modes in a functionally graded piezoelectric material (FGPM) plate. Aluminum nitride has been retained for illustration, it is polarized along the thickness axis, and at the same time the material properties change gradually perpendicularly to the plate with an exponential variation. The effects of the gradient variation on the phase velocity and the coupling electromechanical factor are obtained. Appropriate curves are given to reflect their behavior with respect to frequency. The highest value of the electromechanical coupling factor has been observed for S0 mode, it is close to six percent, conversely for A0 mode it does not exceed 1.5%. The coupling factor maxima undergo a shift toward the high frequency area when the corresponding gradient coefficient increases. The Peano-series method computed under Matlab software, gives rapid convergence and accurate phase velocity when analysing Lamb waves in FGPM plate. The obtained numerical results can be used to design different sensors with high performance working at different frequency ranges by adjusting the extent of the gradient property.

  20. Analysis of Dynamic Fracture Parameters in Functionally Graded Material Plates with Cracks by Graded Finite Element Method and Virtual Crack Closure Technique

    Directory of Open Access Journals (Sweden)

    Li Ming Zhou

    2016-01-01

    Full Text Available Based on the finite element software ABAQUS and graded element method, we developed a dummy node fracture element, wrote the user subroutines UMAT and UEL, and solved the energy release rate component of functionally graded material (FGM plates with cracks. An interface element tailored for the virtual crack closure technique (VCCT was applied. Fixed cracks and moving cracks under dynamic loads were simulated. The results were compared to other VCCT-based analyses. With the implementation of a crack speed function within the element, it can be easily expanded to the cases of varying crack velocities, without convergence difficulty for all cases. Neither singular element nor collapsed element was required. Therefore, due to its simplicity, the VCCT interface element is a potential tool for engineers to conduct dynamic fracture analysis in conjunction with commercial finite element analysis codes.

  1. Development of Functionally Graded Materials for Manufacturing Tools and Dies and Industrial Processing Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Lherbier, Louis, W.; Novotnak, David, J.; Herling, Darrell, R.; Sears, James, W.

    2009-03-23

    Hot forming processes such as forging, die casting and glass forming require tooling that is subjected to high temperatures during the manufacturing of components. Current tooling is adversely affected by prolonged exposure at high temperatures. Initial studies were conducted to determine the root cause of tool failures in a number of applications. Results show that tool failures vary and depend on the operating environment under which they are used. Major root cause failures include (1) thermal softening, (2) fatigue and (3) tool erosion, all of which are affected by process boundary conditions such as lubrication, cooling, process speed, etc. While thermal management is a key to addressing tooling failures, it was clear that new tooling materials with superior high temperature strength could provide improved manufacturing efficiencies. These efficiencies are based on the use of functionally graded materials (FGM), a new subset of hybrid tools with customizable properties that can be fabricated using advanced powder metallurgy manufacturing technologies. Modeling studies of the various hot forming processes helped identify the effect of key variables such as stress, temperature and cooling rate and aid in the selection of tooling materials for specific applications. To address the problem of high temperature strength, several advanced powder metallurgy nickel and cobalt based alloys were selected for evaluation. These materials were manufactured into tooling using two relatively new consolidation processes. One process involved laser powder deposition (LPD) and the second involved a solid state dynamic powder consolidation (SSDPC) process. These processes made possible functionally graded materials (FGM) that resulted in shaped tooling that was monolithic, bi-metallic or substrate coated. Manufacturing of tooling with these processes was determined to be robust and consistent for a variety of materials. Prototype and production testing of FGM tooling showed the

  2. A study of optical reflectance and localization modes of 1-D Fibonacci photonic quasicrystals using different graded dielectric materials

    Science.gov (United States)

    Singh, Bipin K.; Pandey, Praveen C.

    2014-06-01

    In this paper, we present an analytical study on the reflection properties of light through one-dimensional (1-D) quasi-periodic multilayer structures. The considered structures are as follows: F7, F8, F9, (F2)10, (F3)10 and some combinations such as: [(F2)10 (F7) (F2)10], [(F2)10 (F8) (F2)10], [(F3)10 (F7) (F3)10], [(F3)10 (F8) (F3)10], [(F2)10(F3)10], [(F2)10 (F7) (F3)10] and [(F2)10 (F8) (F3)10], where (Fj)n represents n period of the Fibonacci sequence of jth generation. These multilayer structures are considered of two types of layers. One type of layer is considered of graded material like normal, linear or exponential graded material, and the second type of layer is considered of constant refractive index material. Transfer matrix method is utilized to calculate the reflection spectra and localization modes of such structures in the frequency range 150-450 THz. This work would provide the basis of understanding of the effect of graded materials on the reflection and localization modes in Fibonacci photonic quasicrystal structures and obtained spectra can be used in the recognition of grading of materials. The considered heterostructures provide the broad reflection band and some localization modes in the calculated region.

  3. Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties.

    Science.gov (United States)

    Godoy, R F; Coathup, M J; Blunn, G W; Alves, A L; Robotti, P; Goodship, A E

    2016-04-13

    We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 µmØ pores (TiMac400) and 850-1000 µmØ pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-Growth® and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-Growth® showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration.

  4. Research on Current Status of Fabrication Methods for Functionally Graded Material%功能梯度材料制备方法的研究现状

    Institute of Scientific and Technical Information of China (English)

    张勇

    2012-01-01

    介绍了功能梯度材料的基本概念,综述了该材料的制备方法,提出了其发展方向.%The basic concept of functionally graded material was introduced, the different fabrication methods for functionally graded material were described, and the development direction of the material was put forward.

  5. DEVELOPING SIGNS AND SONGS MATERIALS DEALING WITH THE 2013 CURRICULUM FOR THE SEVENTH GRADE STUDENTS IN MTSN BALANG-BALANG

    Directory of Open Access Journals (Sweden)

    Mardiana

    2016-04-01

    Full Text Available This research aimed to develop Signs and Songs Materials based on 2013 curriculum for the Seventh Grade Student at MTsN. BalangBalang, Gowa. It was Research and Development (R&D applied ADDIE model standing for Analysis, Design, Develop, Implement, and Evaluate. The procedures were; 1 analyzing materials needed by students; 2designing the blueprint; 3 developing the materials through the syllabus of 2013 Curriculum; 4 implementing the product (try-out product; and 5 evaluating the product. The product was tried out to the seventh grade students at MTsN Balang-balang. Type of data obtained in this study was qualitative. The instruments used in this study were questionnaire and rubrics for teacher and expert. Then, the teacher and expert were involved in order to validate the product. They validated three systematic aspects of the product, namely; the organization of the Materials, English Teaching strategies or method, and the content of the materials. Finally, based on the teacher and expert judgment as well as try-out design result, it was found that the developed materials were applicable to be taught for the Seventh Grade of Junior High School as additional learning and teaching materials which help both students and teachers in learning process based on 2013 Curriculum.

  6. Basic solutions of multiple parallel symmetric mode-III cracks in functionally graded piezoelectric/piezomagnetic material plane

    Institute of Scientific and Technical Information of China (English)

    泮世东; 周振功; 吴林志

    2013-01-01

    The Schmidt method is adopted to investigate the fracture problem of mul-tiple parallel symmetric and permeable finite length mode-III cracks in a functionally graded piezoelectric/piezomagnetic material plane. This problem is formulated into dual integral equations, in which the unknown variables are the displacement jumps across the crack surfaces. In order to obtain the dual integral equations, the displacement jumps across the crack surfaces are directly expanded as a series of Jacobi polynomials. The results show that the stress, the electric displacement, and the magnetic flux intensity factors of cracks depend on the crack length, the functionally graded parameter, and the distance among the multiple parallel cracks. The crack shielding effect is also obviously presented in a functionally graded piezoelectric/piezomagnetic material plane with mul-tiple parallel symmetric mode-III cracks.

  7. ‘Big Books’ as Mother Tongue-Based Instructional Materials in Bicol for Grade One Pupils

    Directory of Open Access Journals (Sweden)

    Magdalena M. Ocbian,

    2015-11-01

    Full Text Available Language experts claim that it is easier for pupils to learn when the mother tongue is used in the teaching learning process including the learning of a second language. This study determined the reading comprehension level of Grade I pupils in Bulusan Central School for school year 2013-2014 as input in developing big books written in the vernacular that can be used as reading materials for Grade 1 pupils. Results of the evaluation revealed that they belong to the frustration and instructional levels in the literal skill; mostly are frustration readers along interpretative and evaluative skills; but are independent readers along applied skills; hence, they have low level of reading comprehension. Based on the result of the study, three big books as MTB-MLE instructional materials in Bicol were produced to develop or enhance Grade 1 pupils’ reading comprehension. Teaching guides were likewise developed.

  8. Research on Experimental and Application for the High Efficient Enrichment of the Low-grade Precious Metal Materials

    Institute of Scientific and Technical Information of China (English)

    FAN Xingxiang; FU Guangqiang; DONG Haigang; WU Yuedong; LIU Yang; ZHAO Jiachun; WU Xiaofeng; LI Bojie; TONG Weifeng

    2012-01-01

    On the basis of reviewing the progress in the high efficient enrichment from secondary resources of low-grade precious metals at home and abroad,a process route of the high efficient enrichment precious metals from secondary resources of low-grade metals by adding iron oxide as the trapping agent,reducing agent,additive,mixing uniformly and grinding,pelletizing,reduction,grinding and separation,and selectively acid leaching iron has been put forward in this paper.The experiments of reduction,grinding and separation,and selectively acid leaching iron were carried out mainly.Under the decided experiment parameters and conditions,iron generated during the reduction can trap precious metals during reduction,high active alloy powders were obtained from the reduced products by grinding and separation,the concentration of precious metals was obtained by acid leaching high active alloy powders.The better enrichment effect was obtained by adopting the technical route of processing.Other low grade noble metal materials and enrichment ratio of precious metals from the materials to acid products was high through acid leaching.This process has the advantages of simple process,environmental-friendly,strong adaptability of raw materials,high concentration ratio,which was regarded as a kind of the general efficient enrichment technology of low grade precious metal materials.

  9. Sex and Grade Level Differences in Marijuana Use among Youth

    Science.gov (United States)

    King, Keith A.; Vidourek, Rebecca A.; Hoffman, Ashlee R.

    2012-01-01

    A total of 54,361 students in seventh through twelfth grades completed a survey examining the impact of perceived harm of marijuana use, ease of access in obtaining marijuana, and perceived parent/peer disapproval of marijuana use on youth involvement in annual and recent marijuana use. Results indicated that 1 in 6 (16%) students used marijuana…

  10. Sex and Grade Level Differences in Marijuana Use among Youth

    Science.gov (United States)

    King, Keith A.; Vidourek, Rebecca A.; Hoffman, Ashlee R.

    2012-01-01

    A total of 54,361 students in seventh through twelfth grades completed a survey examining the impact of perceived harm of marijuana use, ease of access in obtaining marijuana, and perceived parent/peer disapproval of marijuana use on youth involvement in annual and recent marijuana use. Results indicated that 1 in 6 (16%) students used marijuana…

  11. Fabrication of Al2O3-W Functionally Graded Materials by Slipcasting Method

    Science.gov (United States)

    Katayama, Tomoyuki; Sukenaga, Sohei; Saito, Noritaka; Kagata, Hajime; Nakashima, Kunihiko

    2011-10-01

    We have successfully fabricated a functionally graded material (FGM) from tungsten and alumina powders by a slip-casting method. This FGM has applications as a sealing and conducting component for high-intensity discharge lamps (HiDLs) that have a translucent alumina envelope. Two types of W powder, with different oxidizing properties, were used as the raw powders for the Al2O3-W FGM. "Oxidized W" was prepared by heat-treatment at 200 °C for 180 min in air. Alumina and each of the W powders were mixed in ultrapure water by ultrasonic stirring. The slurry was then cast into a cylindrical acrylic mold, which had a base of porous alumina, under controlled pressure. The green compacts were subsequently dried, and then sintered using a vacuum furnace at 1600 °C for a fixed time. The microstructures of the FGMs were observed by scanning electron microscopy (SEM) of the polished section. The Al2O3-W FGM with the "oxidized W" powder resulted in a microscopic compositional gradient. However, the FGM with "as-received W" showed no compositional gradient. This result was mainly attributed to the difference between the ζ-potentials of the W powders with the different oxidizing conditions; basically "oxidized W" powder tends to disperse because of the larger ζ-potential of the oxide layer coated on the W powder core.

  12. Vibration analysis of nonlocal beams made of functionally graded material in thermal environment

    Science.gov (United States)

    Ebrahimi, Farzad; Reza Barati, Mohammad

    2016-08-01

    In this paper, thermal vibration behavior of functionally graded (FG) nanobeams exposed to various kinds of thermo-mechanical loading including uniform, linear and non-linear temperature rise embedded in a two-parameter elastic foundation are investigated based on third-order shear deformation beam theory which considers the influence of shear deformation without the need to shear correction factors. Material properties of FG nanobeam are supposed to be temperature-dependent and vary gradually along the thickness according to the Mori-Tanaka homogenization scheme. The influence of small scale is captured based on nonlocal elasticity theory of Eringen. The nonlocal equations of motion are derived through Hamilton's principle and they are solved applying analytical solution. The comparison of the obtained results is conducted with those of nonlocal Euler-Bernoulli beam theory and it is demonstrated that the proposed modeling predicts correctly the vibration responses of FG nanobeams. The influences of some parameters including gradient index, nonlocal parameter, mode number, foundation parameters and thermal loading on the thermo-mechanical vibration characteristics of the FG nanobeams are presented.

  13. Thermal stresses in functionally graded materials caused by a laser thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Elperin, T.; Rudin, G. [Department of Mechanical Engineering, Pearlstone Center for Aeronautical Engineering Studies Ben-Gurion University of the Negev, Beer-Sheva (Israel)

    2002-08-01

    Mathematical simulation of a thermal shock method for reliability testing of functionally graded material (FGM) is performed with the end to determine operating parameters of the testing device (power of a laser, laser beam radius, duration of heating) and to investigate the effect of the composition of FGM on a magnitude of thermal stresses in a coating. An analytical method for solution of the thermal elasticity problem is developed whereby the approach of a multilayer plate is used for determining temperature and thermal stresses distributions in a coating. We considered the limiting case of the obtained solution when the thickness of a layer is infinitesimally small and the number of layers tends to infinity. This procedure allowed us to obtain the thermal stresses distribution in a FGM coating. The results for the FGM coating composed of WC (tungsten carbide) ceramics and HS-steel are presented. It is showed that variation of the volume content of ceramics strongly affects thermal stresses in a coating and they decrease significantly in the case of the uniform spatial distribution of ceramics. (orig.)

  14. The First Cycle of Developing Teaching Materials for Fractions in Grade Five Using Realistic Mathematics Education

    Directory of Open Access Journals (Sweden)

    Hongki Julie

    2013-07-01

    Full Text Available There are three questions that will be answered in this study, namely (1 what are the contexts that can be used to introduce the meaning of multiplication of two fractions and to find the result of multiplying two fractions, (2 how to use these contexts to help students construct the understanding of the meaning of multiplication of two fractions and find the result of multiplying two fractions, and (3 what is the impact of the teaching-learning process that has been designed by researchers on the process of students' knowledge construction. Learning approach which was used in developing teaching materials about fractions is realistic mathematics approach. Lesson plan was created for fifth grade elementary school students. The type of research used is developmental research. According to Gravemeijer and Cobb (in Akker, Gravemeijer, McKeney, and Nieveen, 2006 there are three phases in development research, namely (1 preparation of the trial design, (2 the trial design, and (3 retrospective analysis. This paper presents the results of the first cycle of three cycles that have been planned.Key words: fractions, realistic mathematics education, design research. DOI: http://dx.doi.org/10.22342/jme.4.2.415.172-187

  15. Strand I: Physical Health Nutrition. Health Curriculum Materials. Grades 7-9.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    GRADES OR AGES: Grades 7, 8, and 9. SUBJECT MATTER: Physical health and nutrition. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into five sections: nutritional states, adequate diet, nutrition in adolescence, the achievement and maintainance of correct weight, and environmental factors which affect nutritional health. The publication…

  16. Strand III, Mental Health: Health Curriculum Materials for Grades 4, 5, 6.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Elementary Curriculum Development.

    This mental health curriculum guide, intended for use with children in grades four through six, further develops the concepts and understandings introduced in the primary grades. The contents of the guide are presented in outline form and cover the family as a social unit, role arrangements in family life, and the construct of personality. For…

  17. Dynamic behavior of two collinear interface cracks between two dissimilar functionally graded piezoelectric/piezomagnetic material strips

    Institute of Scientific and Technical Information of China (English)

    ZHANG Pei-wei; ZHOU Zhen-gong; WANG Biao

    2007-01-01

    The dynamic interaction oftwo collinear interface cracks between two dislar.functionally graded piezoelectric/piezomagnetic material strips subjected to the anti-plane shear harmonic stress waves was investigated.By using the Fourier transform, unknown variable is jump of displacement across the crack surfaces.These equations are solved using the Schmidt method.Numerical examples are provided to show the effect of the functionally graded parameter,the circular frequency of the incident waves and the thickness of the strip upon stress,electric displacement and magnetic flux intensity factors of cracks.

  18. S1-ZGV Modes of a Linear and Nonlinear Profile for Functionally Graded Material Using Power Series Technique

    Directory of Open Access Journals (Sweden)

    M. Zagrouba

    2014-01-01

    Full Text Available The present work deals with functionally graded materials (FGM isotropic plates in the neighborhood of the first-order symmetric zero group velocity (S1-ZGV point. The mechanical properties of functionally graded material (FGM are assumed to vary continuously through the thickness of the plate and obey a power law of the volume fraction of the constituents. Governing equations for the problem are derived, and the power series technique (PST is employed to solve the recursive equations. The impact of the FGM basic materials properties on S1-ZGV frequency of FGM plate is investigated. Numerical results show that S1-ZGV frequency is comparatively more sensitive to the shear modulus. The gradient coefficient p does not affect the linear dependence of ZGV frequency fo as function of cut-off frequency fc; only the slope is slightly varied.

  19. Behavior of two parallel symmetry permeable cracks in functionally graded piezoelectric materials subjected to an anti-plane shear loading

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The behavior of two parallel symmetry permeable cracks in functionally graded piezoelectric materials subjected to an anti-plane shear loading was investigated. To make the analysis tractable, it was assumed that the material properties varied exponentially with coordinate vertical to the crack. By using the Fourier transform, the problem could be solved with the help of two pairs of dual integral equations, in which the unknown variables were the jumps of the displacements across the crack surfaces. To solve the dual integral equations, the displacement on the crack surfaces expanded in a series of Jacobi polynomials. The normalized stress and electrical displacement intensity factors were determined for different geometric and property parameters for permeable electric boundary conditions. Numerical examples were provided to show the effect of the geometry of the interacting cracks and the functionally graded material parameter upon the stress intensity factors of cracks.

  20. [Study on status of criteria for formulating specification and grade of Chinese medicinal materials based on filed survey in medicine market].

    Science.gov (United States)

    Yang, Guang; Wang, Nuo; Zhan, Zhi-Lai; Wang, Hai-Yang; Jin, Yan

    2016-03-01

    The commodity specification and grade is an important factor affecting the price of Chinese medicinal materials. Specification and grade standard play an important role in transferring quality information in Chinese medicinal market, which is characterized by highly information asymmetry. This paper analyses and expounds six classification methods of commodity specification and grade of Chinese medicinal materials based on the market investigation carried out in the medicine markets in Anguo, Bozhou, Yulin, Chengdu and so on. This study proposes that to formulate the commodity specification and grade standard of Chinese medicinal materials, their efficacy, inspection, purity and beauty should be taken into account orderly. Copyright© by the Chinese Pharmaceutical Association.

  1. Optical reflectance and omnidirectional bandgaps in Fibonacci quasicrystals type 1-D multilayer structures containing exponentially graded material

    Science.gov (United States)

    Singh, Bipin K.; Thapa, Khem B.; Pandey, Praveen C.

    2013-06-01

    A theoretical study of optical reflectance and reflection bands of 1-D photonic quasi-crystals (Fibonacci type arrangement) composed of exponentially graded material is presented. The proposed structures consist of two different layers, one of them is of constant refractive index (L) and the other one is of exponentially graded refractive index (S) dielectric materials. Four different generations (2nd, 3rd, 4th and 5th) of the Fibonacci sequence for 10 periods in one dimension (1-D) are considered and compared in view of their optical reflectance and bandgaps for both TE and TM polarisations. Also, we proposed some heterostructures made by the combination of different Fibonacci generations and their periods to obtain suitable omnidirectional reflection band. We used the transfer matrix method (TMM) to obtain the reflectance, bandgaps and omnidirectional reflectional bandgaps (ODR) of such structures in near infrared spectrum (800-2200 nm) at different angles of incidence. We show that ODR exists in these types of structures. The number of ODRs and total bandgap depend on the Fibonacci generations. Extraordinary ODR bandgaps are obtained in the case of heterostructures formed by the combination of different generations of the Fibonacci sequence. The ODR for these structures is similar to the ODR of photonic crystals containing left-handed materials. This work would be useful to study the Fibonacci type photonic crystals having graded index materials and also it will open new window to design several photonic crystal devices like sensors, reflectors, etc. in the infrared region.

  2. Measuring Engagement in Fourth to Twelfth Grade Classrooms: The Classroom Engagement Inventory

    Science.gov (United States)

    Wang, Ze; Bergin, Christi; Bergin, David A.

    2014-01-01

    Research on factors that may promote engagement is hampered by the absence of a measure of classroom-level engagement. Literature has suggested that engagement may have 3 dimensions--affective, behavioral, and cognitive. No existing engagement scales measure all 3 dimensions at the classroom level. The Classroom Engagement Inventory (CEI) was…

  3. Measuring Engagement in Fourth to Twelfth Grade Classrooms: The Classroom Engagement Inventory

    Science.gov (United States)

    Wang, Ze; Bergin, Christi; Bergin, David A.

    2014-01-01

    Research on factors that may promote engagement is hampered by the absence of a measure of classroom-level engagement. Literature has suggested that engagement may have 3 dimensions--affective, behavioral, and cognitive. No existing engagement scales measure all 3 dimensions at the classroom level. The Classroom Engagement Inventory (CEI) was…

  4. The Perspectives of Twelfth-Grade Students toward the Acquisition of Algebraic Skills throughout High School

    Science.gov (United States)

    Johnson, Melloney W. A.

    2017-01-01

    Too many students do not learn algebra and therefore do not graduate from high school. This basic qualitative study conducted in a large suburban public school district explored the perspectives of high school seniors who were at least 18 years old and at risk for not graduating from high school because they had not demonstrated an adequate…

  5. SCATTERING OF HARMONIC ANTI-PLANE SHEAR STRESS WAVES BY A CRACK IN FUNCTIONALLY GRADED PIEZOELECTRIC/PIEZOMAGNETIC MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Liang Jun

    2007-01-01

    In this paper, the dynamic behavior of a permeable crack in functionally graded piezoelectric/piezomagnetic materials is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with the coordinate parallel to the crack. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations in which the unknown is the jump of displacements across the crack surfaces. These equations are solved to obtain the relations between the electric filed, the magnetic flux field and the dynamic stress field near the crack tips using the Schmidt method. Numerical examples are provided to show the effect pf the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack.

  6. SCATTERING OF ANTI-PLANE SHEAR WAVES IN A FUNCTIONALLY GRADED MATERIAL STRIP WITH AN OFF-CENTER VERTICAL CRACK

    Institute of Scientific and Technical Information of China (English)

    LI Lin; ZHOU Zhen-gong; WANG Biao

    2006-01-01

    The scattering problem of anti-plane shear waves in a functionally graded material strip with an off-center crack is investigated by use of Schmidt method. The crack is vertically to the edge of the strip. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations that the unknown variable is the jump of the displacement across the crack surfaces. To solve the dual integral equations, the jump of the displacement across the crack surfaces was expanded in a series of Jacobi polynomials. Numerical examples were provided to show the effects of the parameter describing the functionally graded materials, the position of the crack and the frequency of the incident waves upon the stress intensity factors of the crack.

  7. Characterization of W/Fe functionally graded materials manufactured by resistance sintering under ultra-high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Dandan [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Zhou, Zhangjian, E-mail: zhouzhangjianustb@163.com [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Tan, Jun [School of Materials Science and Engineering, University of Science and Technology Beijing, 100083 Beijing (China); Aktaa, Jarir [Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2015-02-15

    Highlights: • W/Fe functionally graded material (FGM) are fabricated well by resistance sintering under ultra-high pressure (RSUHP). • The whole sintering time is less than 3 min and cost-effective. • We research the W/Fe interface and the formation of intermetallic at the interface. In addition, we explain the possible method to avoid the formation of brittle intermetallic. • Vickers hardness of W/Fe FGM before and after heat treatment are investigated here. - Abstract: W/Fe-based components are considered as primary structural materials for the future fusion reactor. A five-layer W/Fe functional graded material (FGM) with W volume fraction of 0%, 25%, 50%, 75% and 100%, respectively, have been fabricated by a novel sintering method combining resistance sintering with ultra-high pressure. The sintering was carried out under pressures of 9 GPa and an input power of 11 kW for 60 s. The microstructure of cross-section observed by SEM shows a well-graded transition. The relative density of each layer is more than 97%. A brittle phase Fe{sub 7}W{sub 6} is formed at the interface of W particles and Fe particles, and this intermetallic phase coats Fe particles homogeneously with a thickness of 1–5 μm. It is possible to avoid the brittle phase by choosing appropriate particle size and sintering parameters. In addition, Vickers hardness of W/Fe FGM was investigated before and after heat treatment.

  8. Elastodynamic wave propagation in graded materials: simulations, experiments, phenomena, and applications.

    Science.gov (United States)

    Vollmann, Jacqueline; Profunser, Dieter M; Bryner, Jürg; Dual, Jürg

    2006-12-22

    A two-dimensional numerical simulation model for the elastodynamic wave propagation in two linear elastic, isotropic, joint half-spaces is presented. The border between the two half-spaced is graded in a way, that the values of the elastic properties and the densities vary smoothly (sinusoidally) from the values of one continuum to the values of the other continuum within a transition zone of a defined thickness. It is demonstrated, that a graded layer leads to a frequency and wavelength dependent refraction and reflection behavior of elastodynamic waves. Numerical results show that wavelengths which are long compared with the transition layer thickness are dominantly reflected whereas short waves are dominantly transmitted, a phenomena which does not occur in the case of an infinitely thin transition layer. Furthermore the frequency dependent reflection and transmission behavior of elastodynamic waves is verified experimentally. There the interface between two vapor deposited films is graded due to intermetallic diffusion effects. These graded microstructures are analyzed with a short-pulse-laser-acoustic set-up. The corresponding frequencies of the elastodynamic waves which are filtered with these functionally graded microstructures are in the range of 0.5 THz.

  9. Thermal Stress Calculation and Fabrication of 6063 Al/60SiC-35Al-5Si Graded Materials by Spark Plasma Sintering

    Science.gov (United States)

    Dongming, Zhang; Lianmeng, Zhang; Xiaofeng, Gu; Fei, Chen

    2008-02-01

    The high intensity of thermal stress was generated during fabrication of 6063 aluminum/60SiC-35Al-5Si double-layer material. In order to decrease the thermal stress, graded materials of Al/60SiC-35Al-5Si was fabricated by spark plasma sintering. The CTE in the graded layer was controlled by SiC fraction and particle sizes. The calculation results indicate that the net stress of more than 800 MPa was generated in the double-layer materials, but it decreased to 170 MPa or less in the graded materials. So the stability can be guaranteed in the graded composites. The graded layers also have the potential for high thermal conductivity, more than 180W/Mk for every layer, which satisfies the application.

  10. Thermoelectric properties of p—type Bi—Sb—Te Compositionally Graded thermodelectric materials with different barriers

    Institute of Scientific and Technical Information of China (English)

    GuyingXu; ChangchunGe; 等

    2002-01-01

    In order to find more suitable materials as barriers and to improve the thermoelectric properties,p-type(Bi1-xSbx)2Te3(x=0.85,0.9) two segments compositionally graded thermoelectric materials(CGTM) with different barriers were fabricated by conventional hot pressure method.Metals Fe,Co,Cu and Al were used as barriers between two segments.The effects of different barriers on thermoelectric properties of CGTM were investigated.The results show that metal Fe is more stable and suitable as the barrier.

  11. Thermoelectric properties of p-type Bi-Sb-Te compositionally graded thermoelectric materials with different barriers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to find more suitable materials as barriers and to improve the thermoelectric properties, p-type (BiSb)2Te3 (0.85, 0.9) two segments compositionally graded thermoelectric materials (CGTM) with different barriers were fabricated by conventional hot pressure method. Metals Fe, Co, Cu and Al were used as barriers between two segments. The effects of different barriers on thermoelectric properties of CGTM were investigated. The results show that metal Fe is more stable and suitable as the barrier.

  12. 76 FR 79754 - Twelfth Meeting: RTCA Special Committee 220, Automatic Flight Guidance and Control

    Science.gov (United States)

    2011-12-22

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 220, Automatic Flight Guidance and Control AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION... Return to general plenary meeting Review of WG 2 status--progress, issues and plan Review of WG 3...

  13. 78 FR 16031 - Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems...

    Science.gov (United States)

    2013-03-13

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 225, Rechargeable Lithium Battery and Battery Systems--Small and Medium Size AGENCY: Federal Aviation Administration (FAA), U.S... Lithium Battery and Battery Systems--Small and Medium Size. SUMMARY: The FAA is issuing this notice to...

  14. Microwave synthesis and mechanical characterization of functionally graded material for applications in fusion devices

    Indian Academy of Sciences (India)

    Charu Lata Dube; Yashashri Patil; Shailesh Kanpara; Samir S Khirwadkar; Subhash C Kashyap

    2014-12-01

    Functionally graded tungsten–copper bimetallic compact with fine microstructure and good mechanical property has been synthesized by employing microwave heating method at a temperature of 800 °C and in a short processing time of 30 min. Scanning electron microscopy and energy dispersive X-ray analysis revealed the graded structure of synthesized sample. The fine microstructure of tungsten in each layer is caused by arrested grain growth because of the short sintering time. The overall relative density of the W/Cu functionally graded sample has reached 87% of the theoretical density. Vickers microhardness measurements, across the length of a compact, show increase in hardness value of the sample with the increase in tungsten content. The experimental hardness values match well with the theoretically calculated hardness values.

  15. Thermo-Elastic Analysis Of A Rotating Hollow Cylinder Made Of Arbitrary Functionally Graded Materials*

    Directory of Open Access Journals (Sweden)

    Arefi Mohammad

    2015-12-01

    Full Text Available Thermo-mechanical analysis of the functionally graded orthotropic rotating hollow structures, subjected to thermo-mechanical loadings is studied in this paper. The relations were derived for both plane strain and plane stress conditions as a cylinder and disk, respectively. Non homogeneity was considered arbitrary through thickness direction for all mechanical and thermal properties. The responses of the system including temperature distribution, radial displacement and radial and circumferential stresses were derived in the general state. As case study, power law gradation was assumed for functionally graded cylinder and the mentioned results were evaluated in terms of parameters of the system such as non-homogeneous index and angular velocity.

  16. Screening of various low-grade biomass materials for low temperature gasification: Method development and application

    DEFF Research Database (Denmark)

    Thomsen, Tobias Pape; Ravenni, Giulia; Holm, Jens Kai;

    2015-01-01

    method and the subsequent use of the method to identify promising e but currently unproven, low-grade biomass resources for conversion in Pyroneer systems. The technical assessment is conducted by comparing the results from a series of physical-mechanical and thermochemical experiments to a set of proven...... references. The technical assessment is supplemented by an evaluation of practical application and overall energy balance. Applying the developed method to 4 references and 18 unproven low-grade potential fuels, indicated that one of these unproven candidates was most likely unsuited for Pyroneer...

  17. Development of Integrated Natural Science Teaching Materials Webbed Type with Applying Discourse Analysis on Students Grade VIII in Physics Class

    Science.gov (United States)

    Sukariasih, Luh

    2017-05-01

    This study aims to produce teaching materials integrated natural science (IPA) webbed type of handout types are eligible for use in integrated science teaching. This type of research IS a kind of research and development / Research and Development (R & D) with reference to the 4D development model that is (define, design, develop, and disseminate). Data analysis techniques used to process data from the results of the assessment by the validator expert, and the results of the assessment by teachers and learners while testing is limited (12 students of class VIII SMPN 10 Kendari) using quantitative descriptive data analysis techniques disclosed in the distribution of scores on the scale of five categories grading scale that has been determined. The results of due diligence material gain votes validator material in the category of “very good” and “good”, of the data generated in the feasibility test presentation obtained the category of “good” and “excellent”, from the data generated in the feasibility of graphic test obtained the category of “very good “and” good “, as well as of the data generated in the test the feasibility of using words and language obtained the category of“very good “and” good “, so with qualifications gained the teaching materials IPA integrated type webbed by applying discourse analysis on the theme of energy and food for Junior High School (SMP) grade VIII suitable as teaching materials. In limited testing, data generated in response to a science teacher at SMPN 10 Kendari to product instructional materials as “excellent”, and from the data generated while testing is limited by the 12 students of class VIII SMPN 10 Kendari are more students who score indicates category “very good”, so that the qualification obtained by the natural science (IPA) teaching material integrated type webbed by applying discourse analysis on the theme of energy and food for SMP / class VIII fit for use as teaching material.

  18. The Grading Entropy-based Criteria for Structural Stability of Granular Materials and Filters

    Directory of Open Access Journals (Sweden)

    Janos Lőrincz

    2015-05-01

    Full Text Available This paper deals with three grading entropy-based rules that describe different soil structure stability phenomena: an internal stability rule, a filtering rule and a segregation rule. These rules are elaborated on the basis of a large amount of laboratory testing and from existing knowledge in the field. Use is made of the theory of grading entropy to derive parameters which incorporate all of the information of the grading curve into a pair of entropy-based parameters that allow soils with common behaviours to be grouped into domains on an entropy diagram. Applications of the derived entropy-based rules are presented by examining the reason of a dam failure, by testing against the existing filter rules from the literature, and by giving some examples for the design of non-segregating grading curves (discrete particle size distributions by dry weight. A physical basis for the internal stability rule is established, wherein the higher values of base entropy required for granular stability are shown to reflect the closeness between the mean and maximum grain diameters, which explains how there are sufficient coarser grains to achieve a stable grain skeleton.

  19. Consumer Law-Related Education Materials (Grades 4-7). Okeechobee County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    These teacher-developed learning activities for grades 4-7 deal with consumer law-related topics. The self-contained activities are organized into five sections. Section one contains a role-playing card game that helps students examine rules and feelings. For example, one role-playing situation involves a confrontation between a student and a bus…

  20. Consumer Law-Related Education Materials (Grades 4-7). Hardee County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    Intended for students in grades 4-7, the lessons in this guide focus on law related education. Major objectives are for students to gain an understanding of (1) the laws and legal practices in a democratic society; (2) the concepts of authority, order, property, and justice in the operation of institutions; and (3) the processes and functions of…

  1. Consumer Law-Related Education Materials (Grades 4-7). Highlands County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    Intended for students in grades 4-7, the lessons in this guide focus on consumer law-related education. Major objectives are for students to gain an understanding of (1) the laws and legal practices in a democratic society; (2) the concepts of authority, order, property, and justice in the operation of institutions; and (3) the processes and…

  2. Functionally Graded Thermoelectric Material though One Step Band Gap and Dopant Engineering

    DEFF Research Database (Denmark)

    Jensen, Ellen Marie; Borup, Kasper Andersen; Cederkrantz, Daniel

    gradients. It has previously been shown that a large functionally graded thermoelectric single crystal can be synthesized by the Czochralski method (1). Utilizing element gradients inherent to the Czochralski process we have synthesized a Ge1-xSix:B crystal with a continuously varying x, band gap...

  3. Strand I, Physical Health: Health Status. Health Curriculum Materials for Grades 4-6.

    Science.gov (United States)

    New York State Education Dept., Albany. Curriculum Development Center.

    This health curriculum guide, intended for use with children in grades four through six, contends that the school is in a unique position to supplement efforts by home and community in raising the levels of physical, mental, and social-emotional health for each child. The contents of the guide are presented in outline form and cover observing…

  4. Consumer Law-Related Education Materials (Grades 4-7). Hardee County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    Intended for students in grades 4-7, the lessons in this guide focus on law related education. Major objectives are for students to gain an understanding of (1) the laws and legal practices in a democratic society; (2) the concepts of authority, order, property, and justice in the operation of institutions; and (3) the processes and functions of…

  5. Consumer Law-Related Education Materials (Grades 4-7). Okeechobee County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    These teacher-developed learning activities for grades 4-7 deal with consumer law-related topics. The self-contained activities are organized into five sections. Section one contains a role-playing card game that helps students examine rules and feelings. For example, one role-playing situation involves a confrontation between a student and a bus…

  6. Consumer Law-Related Education Materials (Grades 4-7). Highlands County.

    Science.gov (United States)

    Allen, Rodney F., Ed.; Landry, Russell H., Ed.

    Intended for students in grades 4-7, the lessons in this guide focus on consumer law-related education. Major objectives are for students to gain an understanding of (1) the laws and legal practices in a democratic society; (2) the concepts of authority, order, property, and justice in the operation of institutions; and (3) the processes and…

  7. Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material

    CERN Document Server

    Dalarsson, Mariana; 10.1364/OE.17.006747

    2012-01-01

    We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results obtained by accurate numerical simulations. Our model straightforwardly allows for arbitrary spectral dispersion.

  8. High-temperature thermo-mechanical behavior of functionally graded materials produced by plasma sprayed coating: Experimental and modeling results

    Science.gov (United States)

    Choi, Kang Hyun; Kim, Hyun-Su; Park, Chang Hyun; Kim, Gon-Ho; Baik, Kyoung Ho; Lee, Sung Ho; Kim, Taehyung; Kim, Hyoung Seop

    2016-09-01

    Thermal barrier coatings are widely used in aerospace industries to protect exterior surfaces from harsh environments. In this study, functionally graded materials (FGMs) were investigated with the aim to optimize their high temperature resistance and strength characteristics. NiCrAlY bond coats were deposited on Inconel-617 superalloy substrate specimens by the low vacuum plasma spraying technique. Functionally graded Ni-yttria-stabilized zirconia (YSZ) coatings with gradually varying amounts of YSZ (20%-100%) were fabricated from composite powders by vacuum plasma spraying. Heat shield performance tests were conducted using a high- temperature plasma torch. The temperature distributions were measured using thermocouples at the interfaces of the FGM layers during the tests. A model for predicting the temperature at the bond coating-substrate interface was established. The temperature distributions simulated using the finite element method agreed well with the experimental results.

  9. Demonstration and Validation of Stainless Steel Materials for Critical Above Grade Piping in Highly Corrosive Locations

    Science.gov (United States)

    2017-05-01

    Prepared for Office of the Secretary of Defense (OUSD(AT&L)) Washington, DC 20301-3090 Under Project F07-AR15, “ Advanced Corrosion-Resistant Steel for...world for steel infrastruc- ture . Highly corroded carbon steel pipes at the site were replaced with two grades of stainless steel, and minor corrosion...mitigation modifications were made to pipe supports. After the rehabilitated system was commis- sioned, the pipes were inspected and tested according

  10. The method of fundamental solutions for transient heat conduction in functionally graded materials: some special cases

    Directory of Open Access Journals (Sweden)

    Mohammad Nili Ahmadabadi

    2014-05-01

    Full Text Available In this paper, the Method of Fundamental Solutions (MFS is extended to solve some special cases of the problem of transient heat conduction in functionally graded mate- rials. First, the problem is transformed to a heat equation with constant coecients using a suitable new transformation and then the MFS together with the Tikhonov regularization method is used to solve the resulting equation

  11. Embedding Designed Deformation: towards the computational design of graded material components

    DEFF Research Database (Denmark)

    Nicholas, Paul

    2011-01-01

    Recognising that the process of making materials affords opportunities not available when using existing natural or off-the-shelf materials, the focus of this paper is upon abstraction strategies by which the mechanical properties of composite materials might be engaged within digital architectural...

  12. Optimization design and residual thermal stress analysis of PDC functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    CAO Pin-lu; LIU Bao-chang; YIN Kun; ZHANG Zu-pei

    2006-01-01

    The distribution of thermal stresses in functionally graded polycrystalline diamond compact (PDC) and in single coating of PDC are analyzed respectively by thermo-mechanical finite element analysis (FEA). It is shown that they each have a remarkable stress concentration at the edge of the interfaces. The diamond coatings usually suffer premature failure because of spallation, distortion or defects such as cracks near the interface due to these excessive residual stresses. Results showed that the axial tensile stress in FGM coating is reduced from 840 MPa to 229 MPa compared with single coating, and that the shear stress is reduced from 671 MPa to 471 MPa. Therefore, the single coating is more prone to spallation and cracking than the FGM coating.The effects of the volume compositional distribution factor (n) and the number of the graded layers (L) on the thermal stresses in FGM coating are also discussed respectively. Modelling results showed that the optimum value of the compositional distribution factor is 1.2, and that the best number of the graded layers is 6.

  13. Suitability of Different Food Grade Materials for the Encapsulation of Some Functional Foods Well Reported for Their Advantages and Susceptibility.

    Science.gov (United States)

    Wani, Touseef Ahmed; Shah, Adil Gani; Wani, Sajad Mohd; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad; Nissar, Nazia; Shagoo, Mudasir Ahmad

    2016-11-17

    Functional foods find a very important place in the modern era, where different types of cancer, diabetes, cardiovascular diseases, etc. are on a high. Irrespective of the abundance of bioactive components in different fruits and vegetables, their low solubility in aqueous solution, vulnerability to destruction in different environmental and gastrointestinal conditions and a low intestinal absorption becomes a concern. Because it is quite difficult to commercialize non food materials for the food encapsulation purposes due to their safety concerns in the human body, scientists in the recent times have come up with the idea of encapsulating the different bioactive components in different food grade materials that are able to safeguard these bioactive components against the different environmental and gastrointestinal conditions and ensure their safe and targeted delivery at their absorption sites. Different food grade encapsulation materials including various oligosaccharides, polysaccharides (starch, cyclodextrins, alginates, chitosan, gum arabic, and carboxymethyl cellulose) and proteins and their suitability for encapsulating various bioactive components like flavonoids (catechins, rutin, curcumin, hesperetin, and vanillin), nonflavonoids (resveratrol), carotenoids (β-carotene, lycopene, and lutein), and fatty acids (fish oil, flaxseed oil, and olive oil) of high medical and nutritional value are reviewed here.

  14. Twelfth Semiannual Report of the Commission to the Congress. Major Activities in the Atomic Energy Programs, January - June 1952

    Energy Technology Data Exchange (ETDEWEB)

    Dean, Gordon

    1952-07-01

    The document represents the twelfth semiannual Atomic Energy Commission (AEC) report to Congress. The report sums up the major activities and developments in the national atomic energy program covering the period January - June 1952.

  15. Surface modifications of fusion reactor relevant materials on exposure to fusion grade plasma in plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Niranjan, Ram, E-mail: niranjan@barc.gov.in [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rout, R.K.; Srivastava, R. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chakravarthy, Y. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Mishra, P. [Materials Processing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kaushik, T.C.; Gupta, Satish C. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-11-15

    Graphical abstract: - Highlights: • Exposure of materials (W, Ni, SS, Mo and Cu) to fusion plasma in a plasma focus device. • The erosion and the formations of blisters, pores, craters, micro-cracks after irradiation. • The structural phase transformation in the SS sample after irradiation. • The surface layer alloying of the samples with the plasma focus anode material. - Abstract: An 11.5 kJ plasma focus (PF) device was used here to irradiate materials with fusion grade plasma. The surface modifications of different materials (W, Ni, stainless steel, Mo and Cu) were investigated using various available techniques. The prominent features observed through the scanning electron microscope on the sample surfaces were erosions, cracks, blisters and craters after irradiations. The surface roughness of the samples increased multifold after exposure as measured by the surface profilometer. The X-ray diffraction analysis indicated the changes in the microstructures and the structural phase transformation in surface layers of the samples. We observed change in volumes of austenite and ferrite phases in the stainless steel sample. The energy dispersive X-ray spectroscopic analysis suggested alloying of the surface layer of the samples with elements of the PF anode. We report here the comparative analysis of the surface damages of materials with different physical, thermal and mechanical properties. The investigations will be useful to understand the behavior of the perspective materials for future fusion reactors (either in pure form or in alloy) over the long operations.

  16. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

  17. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Among the...

  18. 3D analysis of functionally graded material plates with complex shapes and various holes

    Institute of Scientific and Technical Information of China (English)

    Zhi-yuan CAO; Shou-gao TANG; Guo-hua CHENG

    2009-01-01

    In this paper, the basic formulae for the semi-analytical graded FEM on FGM members are derived. Since FGM parameters vary along three space coordinates, the parameters can be integrated in mechanical equations. Therefore with the parameters of a given FGM plate, problems of FGM plate under various conditions can be solved. The approach uses 1D discretization to obtain 3D solutions, which is proven to be an effective numerical method for the mechanical analyses of FGM structures. Examples of FGM plates with complex shapes and various holes are presented.

  19. Next Generation Solar Cells Based on Graded Bandgap Device Structures Utilising Rod-Type Nano-Materials

    Directory of Open Access Journals (Sweden)

    Imyhamy M. Dharmadasa

    2015-06-01

    Full Text Available Current solar cells under research and development utilise mainly one absorber layer limiting the photon harvesting capabilities. In order to develop next generation solar cells, research should move towards effective photon harvesting methods utilising low-cost solar energy materials. This will lead to reduce the $W−1 figure for direct solar energy conversion to electrical energy. In this work, a graded bandgap solar cell has been designed to absorb all photons from the UV, visible and IR regions. In addition, impurity PV effect and impact ionisation have been incorporated to enhance charge carrier creation within the same device. This new design has been experimentally tested using the most researched MOCVD grown GaAs/AlGaAs system, in order to confirm its validity. Devices with high Voc ~ 1175 mV and the highest possible FF ~ (0.85–0.87 have been produced, increasing the conversion efficiency to ~20% within only two growth runs. These devices were also experimentally tested for the existence of impurity PV effect and impact ionisation. The devices are PV active in complete darkness producing over 800 mV, Voc indicating the harvesting of IR radiation from the surroundings through impurity PV effect. The quantum efficiency measurements show over 140% signal confirming the contribution to PV action from impact ionisation. Since the concept is successfully proven, the low-cost and scalable electrodeposited semiconducting layers are used to produce graded bandgap solar cell structures. The utilisation of nano- and micro-rod type materials in graded bandgap devices are also presented and discussed in this paper. Preliminary work on glass/FTO/n-ZnS/n-CdS/n-CdTe/Au graded bandgap devices show 10%–12% efficient devices indicating extremely high Jsc values ~48 mA·cm−2, showing the high potential of these devices in achieving higher efficiencies. The detailed results on these low-cost and novel graded bandgap devices are presented in a separate

  20. Playing the role: Power of love and love of power in Shakespeare's Twelfth Night

    Directory of Open Access Journals (Sweden)

    Ljubica Matek

    2014-12-01

    Full Text Available The author uses a methodological approach similar to one of New Historicism to give a new reading of Shakespeare’s comedy Twelfth Night, or What You Will. The play represents both a literary and a historical document which repeats the pattern of appropriating and exercising power used by Queen Elizabeth I. This reading reveals a new interpretative layer of Shakespeare’s seemingly apolitical comedy about mistaken identity and unrequited love which is resolved in a likewise seemingly typical happy ending that includes three marriages. A parallel analysis of text and context will show that Twelfth Night is a socially subversive text which points to the conclusion that masking seems to be a necessary prerequisite for achieving personal and political goals, both in the fictional context of the play and in the historical context of Elizabethan England.

  1. Introduction and session summaries for the proceedings of the twelfth symposium on biotechnology fuels and chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E. (Oak Ridge National Lab., TN (USA)); Wyman, C.E. (Solar Energy Research Inst., Golden, CO (USA))

    1990-01-01

    This Twelfth Symposium on Biotechnology for Fuels and Chemicals continues to provide an annual forum for researchers from industry, universities, and government laboratories to exchange information on recent developments in emerging bioprocessing technologies. As in the past, innovative processing concepts are stressed that are in the early stages of development. The meeting began with a session on Thermal, Chemical, and Biological Processing, followed by two sessions on Applied Biological Research. Next, topics in Bioengineering Research were presented, and a special session on Biotechnology, Bioengineering, and the Solution of Environmental Problems concluded the Twelfth Symposium. Both presentations and posters provided information exchange among meeting participants, and several discussion groups were organized to consider special topics of interest to the meeting participants. This paper presents a brief description of the discussions.

  2. Three-Dimensional Elasticity Solutions for Sound Radiation of Functionally Graded Materials Plates considering State Space Method

    Directory of Open Access Journals (Sweden)

    Tieliang Yang

    2016-01-01

    Full Text Available This paper presents an analytical study for sound radiation of functionally graded materials (FGM plate based on the three-dimensional theory of elasticity. The FGM plate is a mixture of metal and ceramic, and its material properties are assumed to have smooth and continuous variation in the thickness direction according to a power-law distribution in terms of volume fractions of the constituents. Based on the three-dimensional theory of elasticity and state space method, the governing equations with variable coefficients of the FGM plate are derived. The sound radiation of the vibration plate is calculated with Rayleigh integral. Comparisons of the present results with those of solutions in the available literature are made and good agreements are achieved. Finally, some parametric studies are carried out to investigate the sound radiation properties of FGM plates.

  3. Functionally graded polymeric materials: A brif review of current fabrication methods and introduction of a novel fabrication method.

    Science.gov (United States)

    Almasi, Davood; Sadeghi, Maliheh; Lau, Woei Jye; Roozbahani, Fatemeh; Iqbal, Nida

    2016-07-01

    The present work reviews the current fabrication methods of the functionally graded polymeric material (FGPM) and introduces a novel fabrication method that is versatile in applications as compared to those of existing used methods. For the first time electrophoresis was used to control the distribution of the tetracycline hydrochloride (TC) in a film made of polylactic acid (PLA), aiming to induce antimicrobial effect on the film prepared. The elemental analysis on the film surface showed that by employing electrophoresis force, higher amount of TC was detected near the top surface of the film. Results also showed that the FGPM samples with higher percentage of the TC on the film surface were highly effective to minimize the growth of Escherichia coli. These findings are useful and important to improve dispersion quality of the particles in the composite material and further enhance its antibacterial property.

  4. Property Estimation of Functionally Graded Materials Between M2 Tool Steel and Cu Fabricated by Powder Metallurgy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jong-Seol; Shin, Ki-Hoon [Seoul National University of Science and Technology, Seoul (Korea, Republic of)

    2014-09-15

    The use of functionally graded materials (FGMs) may enhance thermal conductivity without reducing the desired strength in many applications such as injection molds embedding conformal cooling channels and cutting tools with heat sinks (or cooling devices). As a fundamental study for cutting tools having FGM heat sinks between M2 tool steel and Cu, six FGM specimens (M2 and Cu powders were premixed such that the relative compositions of M2 and Cu were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt%) were fabricated by powder metallurgy in this study. The cross sections of these specimens were observed by optical microscopy, and then the material properties (such as thermal conductivity, specific heat, and coefficient of thermal expansion) related to heat transfer were measured and analyzed.

  5. Optical and spectroscopic characterizations of Algerian silica raw material to predict high quality solar-grade silicon

    Science.gov (United States)

    Kheloufi, A.; Bobocioiu, E.; Kerkar, F.; Kefaifi, A.; Anas, S.; Medjahed, S. A.; Belkacem, Y.; Keffous, A.

    2017-03-01

    We assess the potential use as raw material for photovoltaics of Algerian silica samples from the quartz veins of the Tirek deposit and quartz sandstones of the Ain Barda deposit. With 97-98% purity, they all require enrichment before their industrial utilization. Acid leaching and gravimetric separation are used to remove the impurities at the grain boundaries and within the crystal lattice. We obtain course, middle, and fine products. The acid leaching process and the gravimetric separation increase the content of SiO2 up to 99.68%; the residue concentration of iron, alumina and zirconium is decreased to 70, 72 and 58 ppm respectively. These values are in agreement with requirements for silica as raw material destined for solar-grade silicon production.

  6. Thermoelastic Theory for the Response of Materials Functionally Graded in Two Directions with Applications to the Free-Edge Problem

    Science.gov (United States)

    Aboudi, Jacob; Pindera, Marek-Jerzy; Arnold, Steven M.

    1995-01-01

    A recently developed micromechanical theory for the thermoelastic response of functionally graded composites with nonuniform fiber spacing in the through-thickness direction is further extended to enable analysis of material architectures characterized by arbitrarily nonuniform fiber spacing in two directions. In contrast to currently employed micromechanical approaches applied to functionally graded materials, which decouple the local and global effects by assuming the existence of a representative volume element at every point within the composite, the new theory explicitly couples the local and global effects. The analytical development is based on volumetric averaging of the various field quantities, together with imposition of boundary and interfacial conditions in an average sense. Results are presented that illustrate the capability of the derived theory to capture local stress gradients at the free edge of a laminated composite plate due to the application of a uniform temperature change. It is further shown that it is possible to reduce the magnitude of these stress concentrations by a proper management of the microstructure of the composite plies near the free edge. Thus by an appropriate tailoring of the microstructure it is possible to reduce or prevent the likelihood of delamination at free edges of standard composite laminates.

  7. SCOPE FOUR-STATE PROFILE, GRADE TWELVE 1966, CALIFORNIA, ILLINOIS, MASSACHUSETTS, NORTH CAROLINA.

    Science.gov (United States)

    TILLERY, DALE; AND OTHERS

    A FOUR-STATE STUDY OF NINTH AND TWELFTH GRADE STUDENTS WAS MADE BY SCOPE (SCHOOL TO COLLEGE--OPPORTUNITIES FOR POSTSECONDARY EDUCATION) TO DISCOVER HOW, WHEN, AND WHY STUDENTS MAKE DECISIONS ABOUT POST-HIGH SCHOOL EDUCATION AND CAREERS. THE INFLUENCE OF PARENTS, SCHOOLS, AND PEERS UPON THE NATURE OF THESE DECISIONS IS ALSO EXAMINED. A COMPOSITE…

  8. Materials characterization and fracture mechanics of a space grade dielectric silicone insulation

    Science.gov (United States)

    Abdel-Latif, A. I.; Tweedie, A. T.

    1982-01-01

    The present investigation is concerned with the DC 93-500 high voltage silicone insulation material employed to pot the gun and the collector end of a traveling wave tube (TWT) used on the Landsat D Satellite. The fracture mechanics behavior of the silicone resin was evaluated by measuring the slow crack velocity as a function of the opening mode of the stress intensity factor at +25 and -10 C, taking into account various uniaxial discrete strain values. It was found that the silicone resins slow crack growth is faster than that for a high voltage insulation polyurethane material at the same stress intensity factor value and room temperature.

  9. The nonlocal solution of two parallel cracks in functionally graded materials subjected to harmonic anti-plane shear waves

    Institute of Scientific and Technical Information of China (English)

    Jun Liang; Shiping Wu; Shanyi Du

    2007-01-01

    In this paper, the dynamic interaction of two parallel cracks in functionally graded materials (FGMs) is investigated by means of the non-local theory. To make the analysis tractable, the shear modulus and the material den-sity are assumed to vary exponentially with the coordinate vertical to the crack. To reduce mathematical difficulties, a one-dimensional non-local kemel is used instead of a two-dimensional one for the dynamic problem to obtain stress fields near the crack tips. By use of the Fourier transform,the problem can be solved with the help of two pairs of dual integral equations, in which the unknown variables are the jumps of displacements across the crack surfaces. To solve the dual integral equations, the jumps of displace-ments across the crack surfaces are expanded in a series of Jacobi polynomials. Unlike the classical elasticity solu-tions, it is found that no stress singularity is present at the crack tips. The non-local elastic solutions yield a finite hoop stress at the crack tips. The present result provides theoret-ical references helpful for evaluating relevant strength and preventing material failure of FGMs with initial cracks. The magnitude of the finite stress field depends on relevant param-eters, such as the crack length, the distance between two parallel cracks, the parameter describing the FGMs, the fre-quency of the incident waves and the lattice parameter of materials.

  10. Membranes for periodontal regeneration: From commercially available to spatially designed and functionally graded materials

    Science.gov (United States)

    Bottino, Marco Cicero

    The aging of the global population will lead to a considerable increase in the number of surgical and restorative procedures related to oral rehabilitation or periodontal regeneration. Periodontitis is one of the most aggressive pathologies that concern the integrity of the periodontal system that can lead to the destruction of the periodontium. Guided tissue and guided bone regeneration (GTR/GBR) have been used for the repair and regeneration of periodontal tissues by utilizing an occlusive membrane. The goal of this dissertation is to advance the knowledge in the area of periodontal regeneration by investigating the properties of a commercially available freeze-dried collagen-based graft (AlloDermRTM) and by designing/fabricating a functionally graded membrane (FGM) via multilayer electrospinning. The effects of different rehydration times and of a simultaneous rehydration/crosslinking procedure on the biomechanical properties and matrix stability of the commercially available membrane were investigated. The results revealed that there are significant changes on the biomechanical properties of the graft as rehydration time increases. Moreover, it was demonstrated that the simultaneous rehydration/crosslinking protocol has a synergistic effect in terms of enhancing biomechanical properties. A FGM consisting of a core-layer (CL) and two functional surface-layers (SL) was fabricated via sequential electrospinning. Hydroxyapatite nanoparticles (n-HAp) were incorporated to enhance bone formation (SL facing bone defect), and metronidazole benzoate (MET) was added to prevent bacterial colonization (SL facing the epithelial tissue). Degradation studies performed on both the CL and the FGM confirmed that the design holds promise in terms of providing the required mechanical stability to avoid membrane collapse and, therefore, enhance bone regeneration. Finally, it was demonstrated that MET incorporation into the SL that would face epithelial tissue is effective in

  11. Japan and Georgia: Economic Partners. For Students in Grade Eight. Instructional Materials about Japan (IMAJ).

    Science.gov (United States)

    Haywood, Jane; Morgan, Nancy

    This manual provides suggestions and materials for teaching about Japan. Designed as a supplement to typical textbook treatments, the lessons provide a range of readings, visuals, and activities to enrich and deepen student learning about Japan. Organized around topics dealing with history, geography, government, economics, and culture, the…

  12. The First Cycle of Developing Teaching Materials for Fractions in Grade Five Using Realistic Mathematics Education

    Directory of Open Access Journals (Sweden)

    Hongki Julie

    2013-07-01

    Full Text Available There are 3 questions that will be answered in this study, namely (1what are the contexts that can be used to introduce the meaning ofmultiplication of two fractions and to find the result of multiplying two fractions, (2 how to use these contexts to help students construct the understanding of the meaning of multiplication of two fractions and find the result of multiplying two fractions, and (3 what is the impact of the teaching-learning process that has been designed by researchers on the process of students’ knowledge construction.Learning approach which was used in developing teaching materialsabout fractions is realistic mathematics approach. Lesson plan wascreated for fifth grade elementary school students. The type of research used is development research. According to Gravemeijer and Cobb (in Akker, Gravemeijer, McKeney, and Nieveen, 2006 there are three phases in development research, namely (1 preparation of the trial design, (2 the trial design, and (3 a retrospective analysis. This paper presents the results of the first cycle of three cycles that have been planned.

  13. Preparation and Mechanical Characterization of Cu-Al2O3 Functionally Graded Material for electrical contact applications

    Directory of Open Access Journals (Sweden)

    Abdul Raheem. K. Abid Ali

    2017-07-01

    Full Text Available In this study, five-layered stepwise Cu/Al2O3 as functionally graded materials have been prepared from copper powder with with five percentage of alumina powder as (5 ,10 ,20 ,30 and 40 Wt% by using powder metallurgy technique. Mixing of copper (34.32 µm and alumina (1.439 µm powders for two hours and then several disk sample with dimensions (14mm diameter and 10 thickness have been compacting at different compacting stresses (550, 650 and 750 MPa. However, sintering of specimens for three hours at 850 under vacuum about has been achieved. The Porosity and density before and after sintering have been calculated. X-ray diffraction analysis showed that tests before and after sintering is similar, there is no new phase formed after sintering. Scanning electron microscopy technique is used to characterize the surface of each layer. Hardness test showed slight linear graded microhardness across the layers without any obvious jumps throughout the thickness. Pin on disc method have been used in determining the wear or material removal of prepared FGM samples. In addition, it was examined thermal conductivity and the electrical resistance have been done in preparing samples from composite and functionally graded material. From the experimental results, it is clear that hardness results change in each layer by producing FGM according to the percentage of the harder constituent (i.e. Al2O3 from 53 to 113 Hv. While Thermal conductivity decrease with the increasing addition weight percentage for α-Al2O3. And Electrical resistance increased when alumina content increased for (5% to 40%. Wear rate improved with the increasing additive percentage of alumina from 0.507 for layer 1 to 0.15 for layer five at 15N and 25 min. Smoothly gradual change of the composition in the Cu/Al2O3 FGM can eliminate the microscopic interface, such as a result as that traditional Cu-Al2O3 joint.

  14. Nutrition Education Printed Materials and Audiovisuals: Grades 7-12, January 1979-May 1990. Quick Bibliography Series: QB 90-80.

    Science.gov (United States)

    Evans, Shirley King

    This annotated bibliography contains 203 citations from AGRICOLA, the U.S. Department of Agriculture database, dating from January 1979 through May 1990. The bibliography cites books, print materials, and audiovisual materials on the subject of nutrition education for grades 7-12. Each citation contains complete bibliographic information,…

  15. Meshless Local Petrov-Galerkin Method for Shallow Shells with Functionally Graded and Orthotropic Material Properties

    Science.gov (United States)

    Sladek, J.; Sladek, V.; Zhang, Ch.

    2008-02-01

    A meshless local Petrov-Galerkin (MLPG) formulation is presented for analysis of shear deformable shallow shells with orthotropic material properties and continuously varying material properties through the shell thickness. Shear deformation of shells described by the Reissner theory is considered. Analyses of shells under static and dynamic loads are given here. For transient elastodynamic case the Laplace-transform is used to eliminate the time dependence of the field variables. A weak formulation with a unit test function transforms the set of the governing equations into local integral equations on local subdomains in the plane domain of the shell. The meshless approximation based on the Moving Least-Squares (MLS) method is employed for the implementation.

  16. Optimizing the design of bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations.

    Science.gov (United States)

    Cui, Chang; Sun, Jian

    2014-01-01

    Due to elastic modulus mismatch between the different layers in all-ceramic dental restorations, high tensile stress concentrates at the interface between the ceramic core and cement. In natural tooth structure, stress concentration is reduced by the functionally graded structure of dentin-enamel junction (DEJ) which interconnects enamel and dentin. Inspired by DEJ, the aim of this study was to explore the optimum design of a bio-inspired functionally graded material (FGM) layer in all-ceramic dental restorations to achieve excellent stress reduction and distribution. Three-dimensional finite element model of a multi-layer structure was developed, which comprised bilayered ceramic, bio-inspired FGM layer, cement, and dentin. Finite element method and first-order optimization technique were used to realize the optimal bio-inspired FGM layer design. The bio-inspired FGM layer significantly reduced stress concentration at the interface between the crown and cement, and stresses were evenly distributed in FGM layer. With the optimal design, an elastic modulus distribution similar to that in DEJ occurred in the FGM layer.

  17. Fabrication of ZrO2/Mo-Si/Ni Functionally Graded Material by Dip-Coating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A slurry dip-coating technique was developed for fabrication of ZrO2/Mo-Si/Ni functionally graded material (FGM)on the stainless steel substrate. The rheological behavior of ZrO2-Ni-ethanol slurry was characterized by viscositytest. The amount of polyvinyl butyral (PVB) additives, which served as the dispersant and binder in ZrO2-Ni-ethanolslurry, was optimized. The results showed that the characters of mixed slurries with added 9 vol. pct (relativelyto total powders) MoSi2 powders prepared by mechanical alloying changed little. The stainless steel substrate wascoated several times by dipping in the slurries, and followed by drying in air every dipping. After debinding in Arin graphite die, the coated FGM plate was finally hot pressed at 1300℃ for 1 h under the pressure of 5 MPa in Arin the same die. Microstructural observations of the sintered FGM specimens revealed that the graded layers wereformed on the stainless steel substrate, in which no cracks were observed.

  18. Nanoscale Graphene Disk: A Natural Functionally Graded Material-How is Fourier's Law Violated along Radius Direction of 2D Disk.

    Science.gov (United States)

    Yang, Nuo; Hu, Shiqian; Ma, Dengke; Lu, Tingyu; Li, Baowen

    2015-10-07

    In this Paper, we investigate numerically and analytically the thermal conductivity of nanoscale graphene disks (NGDs), and discussed the possibility to realize functionally graded material (FGM) with only one material, NGDs. Different from previous studies on divergence/non-diffusive of thermal conductivity in nano-structures with different size, we found a novel non-homogeneous (graded) thermal conductivity along the radius direction in a single nano-disk structure. We found that, instead of a constant value, the NGD has a graded thermal conductivity along the radius direction. That is, Fourier's law of heat conduction is not valid in two dimensional graphene disk structures Moreover, we show the dependent of NGDs' thermal conductivity on radius and temperature. Our study might inspire experimentalists to develop NGD based versatile FGMs, improve understanding of the heat removal of hot spots on chips, and enhance thermoelectric energy conversion efficiency by two dimensional disk with a graded thermal conductivity.

  19. Cracks Near Interfaces in Composites: A Focus on Optical Materials with Graded Microstructures

    Science.gov (United States)

    2010-02-12

    microstructural development of transparent magnesium aluminate spinel; progress was made to understand the specific role of LiF in developing 1. REPORT DATE...develop a fundamental understanding of crack growth near interfaces in optically transparent materials. Transparent magnesium aluminate spinel and a...transparent magnesium aluminate spinel (strength, transparency) is to understand the role of LiF in processing. The PIs continue to reveal the complex

  20. Microstructure and Resisting Thermal Shock Behaviors of TiC-Al2O3/Fe Functionally Graded MaterialsPrepared by SHS/PHIP

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The microstructure and composition of TiC-Al2O3/Fe functionally graded materials (FGM) prepared by self-propagating high temperature synthesis and pseudo-hot isostatic pressing (SHS/PHIP) were studied, and the resisting thermal shock behaviors were analyzed. The results show that TiC-Al2O3/Fe FGM has graded composition distribution. No cross-section crack through the layers was found in the tests of thermal shock and fatigue.

  1. A Novel Fabrication Method for Functionally Graded Materials under Centrifugal Force: The Centrifugal Mixed-Powder Method

    Directory of Open Access Journals (Sweden)

    Eri Miura-Fujiwara

    2009-12-01

    Full Text Available One of the fabrication methods for functionally graded materials (FGMs is a centrifugal solid-particle method, which is an application of the centrifugal casting technique. However, it is the difficult to fabricate FGMs containing nano-particles by the centrifugal solid-particle method. Recently, we proposed a novel fabrication method, which we have named the centrifugal mixed-powder method, by which we can obtain FGMs containing nano-particles. Using this processing method, Cu-based FGMs containing SiC particles and Al-based FGMs containing TiO2 nano-particles on their surfaces have been fabricated. In this article, the microstructure and mechanical property of Cu/SiC and Al/TiO2 FGMs, fabricated by the centrifugal mixed-powder method are reviewed.

  2. Stability and Bifurcation for a Simply Supported Functionally Graded Material Plate with One-to-One Internal Resonance

    Directory of Open Access Journals (Sweden)

    Dongmei Zhang

    2014-01-01

    Full Text Available Stability and bifurcation behaviors for a model of simply supported functionally graded materials rectangular plate subjected to the transversal and in-plane excitations are studied by means of combination of analytical and numerical methods. The resonant case considered here is 1 : 1 internal resonances and primary parametric resonance. Two types of degenerated equilibrium points are studied in detail, which are characterized by a double zero and two negative eigenvalues, and a double zero and a pair of pure imaginary eigenvalues. For each case, the stability regions of the initial equilibrium solution and the critical bifurcation curves are obtained in terms of the system parameters which may lead to Hopf bifurcation and 2D torus. With both analytical and numerical methods, bifurcation behaviors on damping parameters and detuning parameters are studied, respectively. A time integration scheme is used to find the numerical solutions for these bifurcation cases, and numerical results agree with the analytic predictions.

  3. Energy resources of low-grade wood, small wood and waste materials. [Scots Pine; Norway Spruce; Birch

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, A.P.; Sviridyuk, E.P.

    1980-01-01

    An account is made of recent Finnish work on the potential of low-grade wood, small-dimension wood and waste material (of Scots pine, Norway spruce and birch) for power production, in the context of the current world energy crisis. The physical and economic aspects are considered, and the relevance of the Finnish research for the USSR is discussed. In 1978, wood accounted for only 1.4% of the energy balance of the USSR. Taking one t of 'standard fuel' as equal to 7000 kcal for the purposes of calculation, the energy potential of bark alone in the USSR is 13.6 million t/yr. (Refs. 6).

  4. Effects of Varied Shear Correction on the Thermal Vibration of Functionally-Graded Material Shells in an Unsteady Supersonic Flow

    Directory of Open Access Journals (Sweden)

    Chih Chiang Hong

    2017-03-01

    Full Text Available A model is presented for functionally-graded material (FGM, thick, circular cylindrical shells under an unsteady supersonic flow, following first-order shear deformation theory (FSDT with varied shear correction coefficients. Some interesting vibration results of the dynamics are calculated by using the generalized differential quadrature (GDQ method. The varied shear correction coefficients are usually functions of FGM total thickness, power law index, and environment temperature. Two parametric effects of the environmental temperature and FGM power law index on the thermal stress and center deflection are also presented. The novelty of the paper is that the maximum flutter value of the center deflection amplitude can be predicted and occurs at a high frequency of applied heat flux for a supersonic air flow.

  5. Effect of initial stress on Love waves in a piezoelectric structure carrying a functionally graded material layer.

    Science.gov (United States)

    Qian, Zheng-Hua; Jin, Feng; Lu, Tianjian; Kishimoto, Kikuo; Hirose, Sohichi

    2010-01-01

    The effect of initial stress on the propagation behavior of Love waves in a piezoelectric half-space of polarized ceramics carrying a functionally graded material (FGM) layer is analytically investigated in this paper from the three-dimensional equations of linear piezoelectricity. The analytical solutions are obtained for the dispersion relations of Love wave propagating in this kind of structure with initial stress for both electrical open case and electrical short case, respectively. One numerical example is given to graphically illustrate the effect of initial stress on dispersive curve, phase velocity and electromechanical coupling factor of the Love wave propagation. The results reported here are meaningful for the design of surface acoustic wave (SAW) devices with high performance.

  6. Thermal analysis of a functionally graded material subject to a thermal gradient using the boundary element method

    Science.gov (United States)

    Goldberg, Robert K.; Hopkins, Dale A.

    1994-01-01

    The boundary element method is utilized in this study to conduct thermal analysis of functionally graded composites, materials in which the internal microstructure or properties are explicitly tailored in order to obtain an optimal response, on the micromechanical (constituent) scale. A unique feature of the boundary element formulations used here is the use of circular shape functions to convert the two-dimensional integrations of the composite fibers to one dimensional integrations. Using the computer code BEST-CMS, the through the thickness temperature profiles are computed for a representative material with varying numbers of fibers and fiber spacing in the thickness direction. The computed temperature profiles are compared to those obtained using an alternate analytical theory which explicitly couples the heterogeneous microstructure to the global analysis. The boundary element results compared favorably to the analytical calculations, with discrepancies that are explainable based on the boundary element formulation. The results serve both to demonstrate the ability of the boundary element method to analyze these types of materials, and to verify the accuracy of the analytical theory.

  7. Sintering properties of functionally graded materials using coal fly ash and NiCr-based alloy powder

    Energy Technology Data Exchange (ETDEWEB)

    Hasezaki, K.; Nakashita, A.; Kaneko, G.Y.; Kakuda, H. [Shimane University, Shimane (Japan). Dept. of Material Science

    2007-12-15

    Functionally graded materials (FGMs) were prepared by spark plasma sintering using coal fly ash and NiCr alloy powder. The coal fly ash was produced by Misumi coal thermal power station (Chugoku Electric Power Co., Inc.), and 80 mass% nickel and 20 mass% chromium (Fukuda Metal Foil & Powder Co., Ltd) were used as source materials. The sintering was done at 1000{sup o}C in a graphite die. X-ray diffraction patterns of the sintered coal fly ash materials indicated that the mullite (3Al{sub 2}O{sub 3}.2SiO{sub 2}) and silica (SiO{sub 2}) phases were predominant. Direct joining of coal fly ash and NiCr causes a fracture at the interface due to a mismatch of thermal expansion. Cracks in the FGMs were observed between the two layers when the difference of linear thermal expansion coefficient (a) was over 4.2 x 10{sup -6} K{sup -1}, while no cracks were detected in stable FGMs when the difference was less than 4.0 x 10{sup -6} K{sup -1}.

  8. Studies on Interfacial Phenomena in Titanium Carbide/Liquid Steel Systems for Development of Functionally Graded Material

    Science.gov (United States)

    Kiviö, Miia; Holappa, Lauri; Louhenkilpi, Seppo; Nakamoto, Masashi; Tanaka, Toshihiro

    2016-08-01

    In modern materials' applications, versatile, often contradictory requirements are set for properties like high strength, hardness, and toughness. However, e.g., in steel castings, typically only certain surfaces should be hard and wear resistant, whereas the other "bulk" might have only standard properties. Then the critical parts of the surface should be "locally reinforced" to get functionally graded material. Expensive alloying elements are saved, and manufacturing stages are minimized. Titanium carbide is an extremely hard material widely applied in carbide tools. It could be used to reinforce steel castings. When TiC particles are added to liquid steel, wettability, stability, and dissolution are key phenomena that should be understood to better design and control manufacturing processes. In this work, the interfacial phenomena and reactions between TiC and iron/steel melts were examined by wetting experiments with special emphasis on the influence of Cr, Ni, and Mo. No significant effect on wettability was observed by Ni or Mo. High Cr melts showed somewhat higher contact angles. Partial penetration of liquid metal took place in the substrate along the grain boundaries. Ni seemed to promote penetration. During longer experiments, re-precipitation of carbides occurred on the liquid droplet influencing the apparent wetting angle. Cr and Mo promoted carbide formation.

  9. In-situ Al/24Si Functional Graded Materials Prepared by Electromagnetic Separation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Cylinder-like in-situ Al/24Si FGMs were produced by using electromagnetic separating process. Si primary phasereinforced layer with volume fraction as high as 16 pct was formed at the outer region of the cylinder-like sampleswhere the local hardness and wear resistance were enhanced remarkably. Moreover, both of strength and ductility inthe inner region provided insurance of reliable strength for this as-cast gradient material. It indicated that generalmechanical properties such as good wear resistance at the outer region and good ductility in the central part couldbe obtained with the optimized redistribution of the Si primary particles under the electromagnetic force.

  10. Fabrication of W-Cu/Mo-Cu functionally graded materials by explosive consolidation

    Science.gov (United States)

    Chen, Pengwan; Jiang, Zhiming; Shen, Weiping; Yang, Jun; Huang, Fenglei

    2007-06-01

    Attempts are made to use explosive consolidation to fabricate high quality W-Cu/Mo-Cu FGMs. Tungsten powder with 99%purity and a particle size of 3˜25μm and molybdenum/copper powder with >=99% purity and a particle size of 74μm are used as starting powder. A novel technique, called bidirectional underwater shockwave explosive consolidation, is developed. Two water chambers are placed in both sides of the sample. Detonation-generated shock waves are attenuated by the water chambers before acting on the samples. Through adjusting the height of the water columns, the applied pressure can be adjusted. A self-propagating reaction system is used to provide temperature compensation and to enhance consolidation quality. Flash X-ray photography is used to observe the process of explosive consolidation. Various techniques are used to characterize the recovered samples including optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy spectrum analysis, hardness measurement and density measurement. The explosive consolidation methods developed in the paper can be used to other hard-to-consolidate powder materials.

  11. Fracture of functionally graded materials: application to hydrided zircaloy; Fissuration des materiaux a gradient de proprietes: application au zircaloy hydrure

    Energy Technology Data Exchange (ETDEWEB)

    Perales, F

    2005-12-15

    This thesis is devoted to the dynamic fracture of functionally graded materials. More particularly, it deals with the toughness of nuclear cladding at high burnup submitted to transient loading. The fracture is studied at local scale using cohesive zone model in a multi body approach. Cohesive zone models include frictional contact to take into account mixed mode fracture. Non smooth dynamics problems are treated within the Non-Smooth Contact Dynamics framework. A multi scale study is necessary because of the dimension of the clad. At microscopic scale, the effective properties of surface law, between each body, are obtained by periodic numerical homogenization. A two fields Finite Element formulation is so written. An extended formulation of the NSCD framework is obtained. The associated software allows to simulate, in finite deformation, from the crack initiation to post-fracture behavior in heterogeneous materials. At microscopic scale, random RVE calculations are made to determine effective properties. At macroscopic scale, calculations of part of clad are made to determine the role of the mean hydrogen concentration and gradient of hydrogen parameters in the toughness of the clad under dynamic loading. (author)

  12. Investigation on 316L/W functionally graded materials fabricated by mechanical alloying and spark plasma sintering

    Science.gov (United States)

    Tan, Chao; Wang, Guoyu; Ji, Lina; Tong, Yangang; Duan, Xuan-Ming

    2016-02-01

    316L-W (Tungsten) composite materials were fabricated by spark plasma sintering (SPS) of mechanically alloyed 316L-W powders for the development of functionally graded materials (FGMs). The effect of milling parameters on the morphology of the blended 316L/W powders and its subsequent effect on the transition between 316L and W particles during the SPS process were investigated. Samples were characterized by SEM, EDS and XRD analyses. The results so obtained show that with the increase of milling time, the mechanically activated W powder particles become thinner and smoother, with some broken fragments aggregated or inserted in the severely deformed 316L particles. A further SPS process under the conditions of 1050 °C × 45.5 MPa × 5 min leads to the densification of the powder compact and the formation of a distinguishable gray belt surrounding the retained W particles. Such a belt, which has a width of about 2-8 μm depending on different milling parameters and mainly contains Fe7W6, Fe3W3C and Fe2W phases, is bound to be a transitional region between the retained W particles and the 316L matrix. This favorable behavior with regards to the formation of a transitional belt, is accompanied by a substantial increase in the hardness values of the composite.

  13. Twelfth symposium on biotechnology for fuels and chemicals: Program and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Scheitlin, F.M. (ed.)

    1990-01-01

    This report is the program and abstracts of the twelfth symposium on biotechnology for fuels and chemicals, held on May 7--11, 1990, at Gatlinburg, Tennessee. The symposium, sponsored by the Department of Energy, Oak Ridge National Laboratory, Solar Energy Research Institute, Badger Engineers, Inc., Gas Research Institute, and American Chemical Society, consists of five sessions: Session 1, thermal, chemical, and biological processing; Session 2 and 3, applied biological research; Session 4, bioengineering research; and Session 5, biotechnology, bioengineering, and the solution of environmental problems. It also consists of a poster session of the same five subject categories.

  14. NAEP Writing Computer-Based Assessment: An Overview for Grades 8 and 12. NCES 2010-470

    Science.gov (United States)

    National Assessment of Educational Progress (NAEP), 2010

    2010-01-01

    In today's society, writing with paper and pencil has largely been replaced by writing using a computer. Students are expected to compose on a computer as they move through school and into the workforce. Reflecting the changes in technology, eighth- and twelfth-grade students taking the National Assessment of Educational Progress (NAEP) writing…

  15. The Nation's Report Card: Writing 2011. National Assessment of Educational Progress at Grades 8 and 12. NCES 2012-470

    Science.gov (United States)

    National Center for Education Statistics, 2012

    2012-01-01

    This report presents results of the 2011 National Assessment of Educational Progress (NAEP) in writing at grades 8 and 12. In this new national writing assessment sample, 24,100 eighth-graders and 28,100 twelfth-graders engaged with writing tasks and composed their responses on computer. The assessment tasks reflected writing situations common to…

  16. Grade 12 Diploma Examination: Physics 30. June 1986. = Examen en vue du Diplome Douzieme Annee: Physique 30. Juin 1986.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Physics 30 is a twelfth-grade physics course for students in Alberta, Canada. This document is a final test for the course. Both English and French versions of the test are provided. Intended for administration during June 1986, it contains 56 multiple-choice questions and four written-response problems. Two-and-one-half hours are allowed for…

  17. Grade 12 Diploma Examination: Physics 30. January 1987 = Examen en vue du Diplome Douzieme Annee: Physique 30. Janvier 1987.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Physics 30 is a twelfth-grade physics course for students in Alberta, Canada. This document is the major examination for the course. Both English and French versions of the test are provided. Intended for administration during January, 1987, it contains 56 multiple-choice questions and three written-response questions. Two-and-one-half hours are…

  18. Grade 12 Diploma Examination: Mathematics 30. June 1986. = Examen en vue du Diplome Douzieme Annee: Mathematiques 30. Juin 1986.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This is the final test for students in the twelfth-grade course Mathematics 30, offered in schools in Alberta, Canada. Intended for administration in June 1986, it is available in both English and French. It contains 52 multiple-choice questions and five written-response problems, with two-and-one-half hours allowed for completion. Approved…

  19. Grade 12 Diploma Examination: Mathematics 30. January 1988 = Examen en vue du Diplome Douzieme Annee: Mathematiques 30. Janvier 1988.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This is the final test for students in the twelfth grade course Mathematics 30, offered in schools in Alberta, Canada. Intended for administration in 1988, it is available in both English and French. It contains 52 multiple-choice questions and 3 written-response problems, with 2.5 hours allowed for completion. Approved calculators may be used.…

  20. Grade 12 Diploma Examination. Mathematics 30. June 1988 = Examen en vue du Diplome Douzieme Annee. Mathematiques 30. Juin 1988.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This twelfth grade diploma examination is written in both French and English. The test consists of 52 multiple-choice items and three written response questions. Two and one-half hours are provided for taking the test; approved calculators may be used. The test content covers a wide range of mathematical topics including: geometry; trigonometry;…

  1. Grade 12 Diploma Examination: Mathematics 30. January 1987 = Examen en vue du Diplome Douzieme Annee: Mathematiques 30. Janvier 1987.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This is the final test for students in the twelfth-grade course Mathematics 30, offered in schools in Alberta, Canada. Intended for administration in January 1987, it is available in both English and French. It contains 52 multiple-choice questions and 3 written-response problems, with 2.5 hours allowed for completion. Approved calculators may be…

  2. Grade 12 Diploma Examination: Chemistry 30. June 1986. = Examen en vue du Diplome Douzieme Annee: Chimie 30. Juin 1986.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a twelfth-grade chemistry course for students in Alberta, Canada. This document is a final test for the course. Both English and French versions of the test are provided. Intended for administration during June 1986, it contains 56 multiple-choice questions and three written-response problems. Two-and-one-half hours are allowed for…

  3. Qinghai Newly Adds 1 Million Tonnes of Copper and 2 Million Tonnes of Lead Zinc In the “Twelfth Five Year Plan” period

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    The reporter recently learned from Qinghai Province Geological Prospecting Bureau that Qinghai’s geological prospecting for the"Twelfth Five Year Plan"period had made significant breakthroughs,and newly submitted58 orefields.It has been learned that,during the"Twelfth

  4. La Desercion Escolar en los Niveles de Sexto y Noveno Grado: Una Comparacion Entre Zonas Rurales y Urbanas. Boletin 219 (The Educational Desertion in the 6th and 9th Grades: A Comparison Between Rural and Urban Zones. Bulletin 219).

    Science.gov (United States)

    Lopez, Maria I. Hernandez; And Others

    In 1962 and again in 1965, a group of sixth and ninth grade students in selected schools in four Puerto Rican communities were interviewed to investigate the factors influencing students' decision to withdraw from school before completing twelfth grade and to identify some characteristics of dropouts. Of 616 students interviewed in 1962, 20.9% of…

  5. La Desercion Escolar en los Niveles de Sexto y Noveno Grado: Una Comparacion Entre Zonas Rurales y Urbanas. Boletin 219 (The Educational Desertion in the 6th and 9th Grades: A Comparison Between Rural and Urban Zones. Bulletin 219).

    Science.gov (United States)

    Lopez, Maria I. Hernandez; And Others

    In 1962 and again in 1965, a group of sixth and ninth grade students in selected schools in four Puerto Rican communities were interviewed to investigate the factors influencing students' decision to withdraw from school before completing twelfth grade and to identify some characteristics of dropouts. Of 616 students interviewed in 1962, 20.9% of…

  6. The Roots of Fencing from the Twelfth to the Fourteenth Centuries in the French Language Area

    Directory of Open Access Journals (Sweden)

    Dupuis Olivier

    2015-05-01

    Full Text Available This article offers a partial overview on fencing, as recognized through archive records, as well as French epics and romances from the twelfth to the early fourteenth century. In the twelfth century, fencing was only attested through knightly vocabulary as a way to describe actions performed during single combats involving a combination of shield and another weapon, most commonly a sword. Fencing was progressively dissociated from the knightly arts and there were even few mentions of its use by common people. There are archive records from the thirteenth century of individuals bearing the nickname “fencer”, although there is rarely enough context to be certain that they were really practicing the art. At the end of the thirteenth century, archives and narrative fiction show an established fashion for a certain form of fencing with a short round shield, the buckler. This is clearly established in London where surviving manuscripts include many regulations on fencing, however the fashion was also spread in the continent, even though it seems to be less documented.

  7. Before Grosseteste: Roger of Hereford and calendar reform in eleventh- and twelfth-century England.

    Science.gov (United States)

    Moreton, J.

    1995-12-01

    The existence in the West Country - that area of England that is nearest to the Welsh border - in the eleventh and twelfth centuries of a group of scholars with scientific interests has long been recognized. The part that compotus played in the development of these interests was noted, but it has not been studied in any detail. It was here that a proposal for a reform of the ecclesiastical calendar, based not only on the reckoning traditionally attributed to Dionysius Exiguus but relating also to observed phenomena, was arrived at, then verified with the use of newly available scientific ideas from Arabic sources. One reason for the neglect of this topic is that three very important computistical treatises - the eleventh-century Compotus of Gerland and those of Roger of Hereford and the writer who has been identified with a certain "Constabularius", both from the twelfth century - have not been printed. The aim of this article is to explain why the study of compotus flourished in the West Country and then to examine its development in these and related treatises.

  8. Idiopathic Ninth, Tenth, and Twelfth Cranial Nerve Palsy with Ipsilateral Headache: A Case Report

    Directory of Open Access Journals (Sweden)

    Sun Seung-Ho

    2012-12-01

    Full Text Available Objective: This case report is to report the effect of Korean traditional treatment for idiopathic ninth, tenth, and twelfth cranial nerve palsy with ipsilateral headache. Methods: The medical history and imaging and laboratory test of a 39-year-old man with cranial palsy were tested to identify the cause of disease. A 0.2-mL dosage of Hwangyeonhaedoktang pharmacopuncture was administered at CV23 and CV17, respectively. Acupuncture was applied at P06, Li05, TE05, and G37 on the right side of the body. Zhuapiandutongbang (左偏頭痛方 was administered at 30 minutes to 1 hour after mealtime three times a day. The symptoms were investigated using Visual Analogue Scale (VAS. Results: The results of magnetic resonance imaging (MRI, computed tomography (CT, and laboratory tests were normal. The medical history showed no trauma, other illnesses, family history of diseases, medications, smoking, drinking and so on. All symptoms disappeared at the 10th day of treatment. Conclusion: Korean traditional treatment such as acupuncture, pharmcopuncture, and herbal medicine for the treatment of ninth, tenth, and twelfth cranial nerve palsy of unknown origin is suggested to be effective even though this conclusion is based on a single.

  9. Gender-Based Content of Educational Materials for the Study of Serbian Language in Lower-Stage Grades of Elementary Education

    Science.gov (United States)

    Trifunovic, Vesna; Petrovic, Ruzica

    2014-01-01

    This paper presents the results of analysis of educational materials for the study of Serbian language in lower-stage grades of elementary education (intended for students from 7 through 11 years old) from gender perspective. The first part of the paper presents the process of institutionalization of gender-based education in the Republic of…

  10. Using Graded Peer Evaluation to Improve Students' Writing Skills, Critical Thinking Ability, and Comprehension of Material in a Principles of Public Relations Course

    Science.gov (United States)

    Todd, Vicki; Hudson, Jerry C.

    2007-01-01

    This peer-evaluation assignment encouraged students to think critically, synthesize information and write about public relations course material rather than incorporate surface information into written assignments. Because peer reviewers can improve the grades on their final papers by offering concrete suggestions to the original authors, students…

  11. Research Examination of the Options to Increase the Education Effectiveness in the Technical Subjects at the 7th Grade of Elementary School Using Hypertext Educational Material

    Science.gov (United States)

    Žácok, L'ubomir

    2010-01-01

    The utilization of hypertext educational material is going to be solved in this paper as a source using which the effectiveness of education the technical subjects at the 7th grade of elementary school can be increased. As a comparison between reached results in the control and experimental groups of pupils we used final didactical examination,…

  12. Fabrication of Al-Al3Ti/Ti3Al Functionally Graded Materials under a Centrifugal Force

    Directory of Open Access Journals (Sweden)

    Yoshimi Watanabe

    2010-09-01

    Full Text Available Fabrication of Al-Al3Ti functionally graded materials (FGMs under the centrifugal force has recently attracted some attention. The controlled compositional gradient of the fabricated FGMs, the low cost of the process, and the good mold filling, are the main advantages of the centrifugal method (CM. Using the conventional CM techniques such as the centrifugal solid-particle method and centrifugal in-situ method, FGMs rings with gradually distributed properties could be achieved. As a more practical choice, the centrifugal mixed-powder method (CMPM was recently proposed to obtain FGMs containing nano-particles selectively dispersed in the outer surface of the fabricated parts. However, if a control of the particles morphology, compound formulas or sizes, is desired, another CM technique is favored. As a development of CMPM, our novel reaction centrifugal mixed-powder method (RCMPM has been presented. Using RCMPM, Al‑Al3Ti/Ti3Al FGMs with good surface properties and temperature controlled compositional gradient could be achieved. In this short review, this novel method will be discussed in detail and the effect of RCMPM processing temperature on the reinforcement particles morphology, size and distribution through the fabricated samples, will be reviewed.

  13. Multiscale Modeling of Structurally-Graded Materials Using Discrete Dislocation Plasticity Models and Continuum Crystal Plasticity Models

    Science.gov (United States)

    Saether, Erik; Hochhalter, Jacob D.; Glaessgen, Edward H.

    2012-01-01

    A multiscale modeling methodology that combines the predictive capability of discrete dislocation plasticity and the computational efficiency of continuum crystal plasticity is developed. Single crystal configurations of different grain sizes modeled with periodic boundary conditions are analyzed using discrete dislocation plasticity (DD) to obtain grain size-dependent stress-strain predictions. These relationships are mapped into crystal plasticity parameters to develop a multiscale DD/CP model for continuum level simulations. A polycrystal model of a structurally-graded microstructure is developed, analyzed and used as a benchmark for comparison between the multiscale DD/CP model and the DD predictions. The multiscale DD/CP model follows the DD predictions closely up to an initial peak stress and then follows a strain hardening path that is parallel but somewhat offset from the DD predictions. The difference is believed to be from a combination of the strain rate in the DD simulation and the inability of the DD/CP model to represent non-monotonic material response.

  14. Fabrication of Al/Al3Ti Functionally Graded Materials by Reaction Centrifugal Mixed-Powder Method

    Science.gov (United States)

    El-Hadad, Shimaa; Sato, Hisashi; Miura-Fujiwara, Eri; Watanabe, Yoshimi

    2011-01-01

    Formation of compositional gradient in Al/Al3Ti Functionally graded materials (FGMs) fabricated by the centrifugal method (CM) depends mainly on the centrifugal force and the processing temperature. In this study, a novel centrifugal method, reaction centrifugal mixed-powder method (RCMPM), was proposed to fabricate Al/Al3Ti FGMs under fixed centrifugal force (G=80). The effects of RCMPM processing temperature on the formation of Al3Ti intermetallics, its morphology and its distribution in the fabricated Al/Al3Ti FGMs have been investigated. Fine granular Al3Ti were observed at relatively lower processing temperature while the known coarse platelet-like particles of Al3Ti could be achieved at higher casting temperatures. Moreover, Ti3Al intermetallics compound and unreacted Ti phases are also observed along with Al3Ti particles. In addition, distribution of Al3Ti intermetallics size and their volume fraction showed a significant change when the Al/Al3Ti FGMs processed at different temperatures relative to the liquidus temperature of the master alloy.

  15. THE FOOTWEAR DESIGNING SESSION USING CRISPIN DYNAMICS ENGINEER. PART II: Creating the parts, Estimating the material consumption, Grading

    Directory of Open Access Journals (Sweden)

    IOVAN-DRAGOMIR Alina

    2015-05-01

    Full Text Available The diversification and customization of products are important characteristic of the modern economy and especially of the fashion industry. Because of this, the lifetime of the footwear product is very short and result the necessity to cut the design and production time. By classic methodology, designing footwear is a very complex and laborious activity. That is because classic methodology requires many graphic executions using manual means, which consume a lot of the producer’s time. With CRISPIN Dynamics, one can visualize a range of designs on-screen; work out the costs of a new style and even cut out sample shoe components. Reliance on manual skills is largely eliminated, so the staff can work creatively, but with increased accuracy and productivity. One can even send designs to a distant office or manufacturing centre in a matter of minutes. This paper presents the basic function of CRISPIN Dynamics CAD Suite Engineer for footwear design. The process of new product development has six stapes: digitized form of the medium copy, last flatting, model drawing, creation and management of individual parts, estimation of material consumption, multiplying the designed footwear product’s pattern. This product has been developed for shoemakers who wish to ensure that their business remains competitive by increasing the efficiency, speed and accuracy of pattern development and grading.

  16. Optimization of Electrode Material for EDM Die-sinking of Titanium Alloy Grade 5 - Ti6Al4V

    Directory of Open Access Journals (Sweden)

    Sangeeth Suresh

    2016-08-01

    Full Text Available Titanium alloy grade 5, Ti6Al4V, is extensively gaining importance in the industrial environment, specifically in aerospace, medical and automotive domains, mainly due to its exceptional blend of mechanical properties like high hardness which is further heat treatable, high strength-to-weight ratio which makes it light, high corrosion and temperature resistance etc. However, the same properties undervalue Ti6Al4V as a conventionally difficult-to-machine material. Rapid tool wear, excessive heat generation, dimensional instability and loss of surface integrity are the issues that plague the conventional machining of Ti6Al4V.  In view of these facts, non-traditional machining processes like electron discharge machining (EDM - die sinking and wire cut prove to be a substitute for the conventional machining. In this study, an experimental optimization of EDM die-sinking electrode materials among copper, brass and graphite, is carried out. Experimental design is created using a statistical tool and actual machining is carried out to record the surface roughness, variations on the surface hardness and dimensional stability. Quality evaluation and statistical analysis substantiates graphite electrodes to produce better surface finish-Ra 2.05microns with minimal dimensional variation-less than 10%-when operated at minimum spark gaps. It is inferred that graphite electrodes exhibit higher resistivity towards current than its counterparts thus passing minimum spark energy preventing excessive self-wear and a dimensionally accurate workpiece. The depth of machining highly impacts the variations on the surface hardness post machining.

  17. Strand V: Education for Survival. First Aid and Survival Education. Health Curriculum Materials Grades 10-12.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    GRADES OR AGES: Grades 10-12. SUBJECT MATTER: First aid and survival education. ORGANIZATION AND PHYSICAL APPEARANCE: The guide is divided into six sections: transportation of the injured, automobile accidents, conditions resulting from nuclear explosion, chemical warfare, natural catastrophes, and psychological first aid. The publication format…

  18. Computer Assisted Educational Material Preparation for Fourth Grade Primary School Students’ English Language Class in Teaching Numbers

    Directory of Open Access Journals (Sweden)

    Abdulkadir Yüzen

    2016-03-01

    Full Text Available In this study, using ADDIE instructional design model, it is aimed to prepare English language educational material for 4th grade primary students to teach them numbers. At the same time, ARCS model of motivation’s attention, relevance and satisfaction phases are also taken into consideration. This study also comprises of Design Based Research which includes design, theory and application processes. The first phase of the ADDIE method is the analysis where there is a discussion with primary school English language teachers so as to determine the topic, the content and the target groups. During the design phase; objectives, strategies, activities, assessments, and methods of learning are determined to organize and present the content on the basis of learning objectives. In the development phase; images, animations and user interface are created in accordance with students’ ages. Additionally, sounds including the pronunciation of digits and numbers are created and the codes of the visual scenarios that are designed are written in ActionScript 2.0 in Adobe Flash CS3 Professional. At the implementation phase, some of the target group students are tested with prototype material that has been implemented. In the classroom, students learn both the pronunciation and the spelling of the numbers. After checking their spelling and typing errors of numbers with quizzes, the students repeat what they have learned and then they take the spelling quizzes. The program checks the misspelled words. Students who correctly complete the quizzes are entitled to have one flag. And when they have all the flags (4 flag, they receive a certificate of achievement. With this rewarding technique, it is intended to raise the motivation of the students. Finally, at the evaluation step, the observed problems in the materials are revised. At every stage of the process, expert evaluations are consulted. With this study that is based on ADDIE instructional designed model and

  19. The non-local theory solution of a Griffith crack in functionally graded materials subjected to the harmonic anti-plane shear waves

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the dynamic stress field near crack tips in the functionally graded materials subjected to the harmonic anti-plane shear stress waves was investi- gated by means of the non-local theory. The traditional concepts of the non-local theory were extended to solve the fracture problem of functionally graded materials. To make the analysis tractable, it was assumed that the material properties vary exponentially with coordinate parallel to the crack. By use of the Fourier transform, the problem can be solved with the help of a pair of dual integral equations, in which the unknown variable was the displacement on the crack surfaces. To solve the dual integral equations, the displacement on the crack surfaces was expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularities are present at crack tips. The non-local elastic solutions yield a finite hoop stress at crack tips, thus allowing us to use the maximum stress as a fracture criterion. The magnitude of the finite dynamic stress field depends on the crack length, the parameter describing the functionally graded materials, the circular frequency of the incident waves and the lattice parameter of materials.

  20. The non-local theory solution of a Griffith crack in functionally graded materials subjected to the harmonic anti-plane shear waves

    Institute of Scientific and Technical Information of China (English)

    ZHANG PeiWei; ZHOU ZhenGong; WU LinZhi

    2007-01-01

    In this paper, the dynamic stress field near crack tips in the functionally graded materials subjected to the harmonic anti-plane shear stress waves was investigated by means of the non-local theory. The traditional concepts of the non-local theory were extended to solve the fracture problem of functionally graded materials.To make the analysis tractable, it was assumed that the material properties vary exponentially with coordinate parallel to the crack. By use of the Fourier transform,the problem can be solved with the help of a pair of dual integral equations, in which the unknown variable was the displacement on the crack surfaces. To solve the dual integral equations, the displacement on the crack surfaces was expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularities are present at crack tips. The non-local elastic solutions yield a finite hoop stress at crack tips, thus allowing us to use the maximum stress as a fracture criterion. The magnitude of the finite dynamic stress field depends on the crack length, the parameter describing the functionally graded materials, the circular frequency of the incident waves and the lattice parameter of materials.

  1. 76 FR 17473 - Twelfth Meeting: RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data...

    Science.gov (United States)

    2011-03-29

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 214: Working Group 78: Standards...: Notice of RTCA Special Committee 214: Working Group 78: Standards for Air Traffic Data Communication... Committee 214: Working Group 78: Standards for Air Traffic Data Communication Services. DATES: The...

  2. Comparison of Political Attitudes of German and American Twelfth Year Students: Perspectives on the Rights of Individuals.

    Science.gov (United States)

    Hepburn, Mary A.

    A broad survey of democratic political attitudes of United States and West German students was developed jointly by the Governmental Education Division of the Vinson Institute of Government at the University of Georgia and the Bundeszentrale fur politische Bildung in Bonn. This survey sought to probe twelfth-year students' attitudes toward…

  3. 75 FR 11116 - Certain Pasta from Italy: Notice of Amended Final Results of the Twelfth Antidumping Duty...

    Science.gov (United States)

    2010-03-10

    ... Results of the Twelfth Administrative Review, 75 FR 6352 (February 9, 2010) (Final Results). We are... Antidumping Duty Changed Circumstances Review and Revocation, in Part, 74 FR 41120 (August 14, 2009). The... clarified its ``automatic assessment''' regulation on May 6, 2003 (68 FR 23954). This clarification...

  4. The Twelfth US Air Force. Tactical and Operational Innovations in the Mediterranean Theater of Operations, 1943-1944

    Science.gov (United States)

    2007-02-01

    Husky was a strategic success, contributing to the resignation of Italian dictator Benito Mussolini on 25 July 1943, and the 30 OPERATION HUSKY AND... Mussolini and the surrender of Italy. The Italian capitulation forced the Germans to defend Italy alone with overstretched forces. The Twelfth Air Force

  5. The properties of thickness-twist (TT) wave modes in a rotated Y-cut quartz plate with a functionally graded material top layer.

    Science.gov (United States)

    Wang, Bin; Qian, Zhenghua; Li, Nian; Sarraf, Hamid

    2016-01-01

    We propose the use of thickness-twist (TT) wave modes of an AT-cut quartz crystal plate resonator for measurement of material parameters, such as stiffness, density and material gradient, of a functionally graded material (FGM) layer on its surface, whose material property varies exponentially in thickness direction. A theoretical analysis of dispersion relations for TT waves is presented using Mindlin's plate theory, with displacement mode shapes plotted, and the existence of face-shear (FS) wave modes discussed. Through numerical examples, the effects of material parameters (stiffness, density and material gradient) on dispersion curves, cutoff frequencies and mode shapes are thoroughly examined, which can act as a theoretical reference for measurements of unknown properties of FGM layer.

  6. Forecast of Grain Production of China during the Twelfth Five-Year Plan Period

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to the latest revised agricultural economic statistical data in China Statistical Yearbook-2010,by selecting and establishing the square root-treated grey model,the empirical analysis and forecast research on the grain output of China from 2011 to 2015 are conducted.The results show that the grain output of China in 2011 will reach 557.739 million tons,and it will break through 600 million tons at 605.617 million tons in 2015.The persistent and stable grain output will ensure that the national economy develops in normal during the twelfth five-year plan period and remit the world grain crisis efficiently;meanwhile,the problem of exorbitant grain prices should be remitted in some level.

  7. Proceedings of the twelfth international symposium on remote sensing of environment

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This is the third of three volumes of the proceedings of the Twelfth International Symposium on Remote Sensing of Environment, held 20 to 26 April 1978 in Manila, Philippines. This symposium is part of a continuing program investigating current activities in the field of remote sensing. The meeting is intended to promote increased international cooperation in research, development and application of this technology, and to stimulate an exchange of information on all aspects of this multidisciplinary field through the presentation of reports on work planned, in progress or completed. Presentations include those concerned with the utilization of this technology in various national and international programs as well as in numerous applications for monitoring and managing the earth's resources and man's global environment. Ground-based, airborne, and spaceborne sensor systems and both manual and machine-assisted data analysis and interpretation are included. All papers included in their entirety were abstracted and indexed for EDB/ERA.

  8. Special issue “International Geomagnetic Reference Field—the twelfth generation”

    DEFF Research Database (Denmark)

    Thébault, E.; Finlay, C. C.; Toh, H.

    2015-01-01

    is a series of standard mathematical models describing the large scale internal part of the Earth’s magnetic field between epochs 1900.0 and 2015.0 with a forecast to epoch 2020.0. This activity has been maintained since 1968 by a working group of volunteer scientists from several international institutions......This special issue of Earth, Planets and Space, synthesizes the efforts made during the construction of the twelfth generation of the International Geomagnetic Reference Field (IGRF-12) that was released online in December 2014 (http://www.ngdc.noaa.gov/IAGA/vmod/ igrf.html). The IGRF-12...... and Geophysics/Union Internationale de Géodésie et Géophysique (IUGG/UIGG), an “international organization dedicated to advancing, promoting, and communicating knowledge of the Earth system, its space environment, and the dynamical processes causing change” (http://www.iugg.org/)....

  9. Influence of graded index materials on the photonic localization in one-dimensional quasiperiodic (Thue-Mosre and Double-Periodic) photonic crystals

    Science.gov (United States)

    Singh, Bipin K.; Pandey, Praveen C.

    2014-12-01

    In this paper, we present the investigation on the photonic localization and band gaps in quasi-periodic photonic crystals containing graded index materials using a transfer matrix method in region 150-750 THz of the electromagnetic spectrum. The graded layers have a space dispersive refractive index, which vary in a linear and exponential fashion as a function of the depth of layer. The considered quasiperiodic structures are taken in the form of Thue-Morse and Double-Periodic sequences. The grading profile in the layers affects the position of reflection dips and forbidden bands, and frequency region of the bands. We observed that vast number of forbidden band gaps and dips are developed in its reflection spectra by increasing the number of quasi-periodic generation. Moreover, we compare the total forbidden bandwidths with increasing the generation of the quasi-periodic sequences for the structures with linear and exponential graded layer. Results show that the different graded profiles with same boundary refractive index can change the position of localization modes, number of photonic bands and change the frequency region of the bands. Therefore, we can achieve suitable photonic band gaps and modes by choosing the different gradation profiles of the refractive index and generation of the quasi-periodic sequences.

  10. Design of Co-sedimentation Experiments Used to Fabricate Functionally Graded Materials with a Continuous Change of Composition

    Institute of Scientific and Technical Information of China (English)

    YANG Zhong-min; GONG Dao-ren; ZHANG Lian-meng

    2004-01-01

    In the process of particle settling in a dilute,a density graded distribution of the liquid below the suspension needs to be designed according to the gravity of the suspension prior to sedimentation.In the present paper a compositionally graded W-Mo composite was formed via the settling of the W and Mo particles,with a density gradient distributed in the initial clear liquid along the settling direction.

  11. Comparison of Two Small-Group Learning Methods in 12th-Grade Physics Classes Focusing on Intrinsic Motivation and Academic Performance

    Science.gov (United States)

    Berger, Roland; Hanze, Martin

    2009-01-01

    Twelfth-grade physics classes with 344 students participated in a quasi-experimental study comparing two small-group learning settings. In the jigsaw classroom, in contrast to the cyclical rotation method, teaching expectancy as well as resource interdependence is established. The study is based on the self-determination theory of motivation,…

  12. Supply of equipment and components, materials of dedicated commercial grade, other services; Suministro de equipos y respuestos. Materiales de grado comercial dedicados. Otros servicios

    Energy Technology Data Exchange (ETDEWEB)

    Perdices, D.; Perez Medina, E.

    2014-10-01

    The following article describes the course of action of Tecnatom as Procurement Agent and Manufacturing Manager for the supply materials, equipment and components for the Spanish Nuclear Power Plants. We have devoted a special mention to the supply of dedicated commercial grade items (CGI), bringing together the services of Manufacturing Manager, Engineering service and testing facilities, simplifying the control of the supply chain with total warranty. (Author)

  13. Oxidation behavior of nuclear graphite and the improvement of corrosion resistance and thermal shock resistance of graphite materials by compositionally graded SiC coating

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Kimio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-08-01

    Since nuclear grade graphite is a porous solid, its oxidation is a good example of a heterogeneous reaction between gases and a porous solid. Changes in properties of graphite and carbon materials caused by corrosion reactions with water vapor or air cannot be evaluated simply on the basis of weight loss only, because the manner in which the corrosion proceeds into the interior of the materials is quite different from one grade to another. In the reaction at higher temperatures, oxygen reacts with carbon at the surface of graphite and the grains are removed gradually, leading to what is called decrease in thickness'. In this case, although specimen or component made of graphite becomes thinner or decreases its dimensions, its properties such as mechanical strength and thermal conductivity are unaltered. On the other hand, at lower temperatures there are little dimensional changes found in graphite, but corrosion reaction proceeds into the interior of the material because of the relatively low corrosion rate at the surface. Besides, the binder region is preferentially corroded so that the binding force between the grains decreases, causing the separation of grains to lead to significant losses of strength and thermal conductivity. For this reason, it is essential to pay attention to the corrosion in the interior of the material as well as temperature and atmosphere, when it is used for structural components. This report summarizes the results obtained in the experiments in which several nuclear-grade graphites are corroded with water vapor or air in the chemical reaction control and in-pore diffusion control regimes. (1) Difference in the corrosion behavior among the graphite grades is clarified and the relationship between the total weight loss and penetration depth was examined by introducing a parameter common to all the graphite grades, characteristic corrosion length, L{sub B}. (2) Measurements of the surface area of corroded specimens led us find the

  14. Localized corrosion studies on materials proposed for a safety-grade sodium-to- air decay-heat removal system for fast breeder reactors

    Science.gov (United States)

    Kamachi Mudali, U.; Khatak, H. S.; Dayal, R. K.; Gnanamoorthy, J. B.

    1993-02-01

    The present investigation was carried out to assess the localized corrosion resistance of materials proposed for the construction of the safety-grade sodium-to-air decay-heat removal system for fast breeder reactors. The materials, such as Alloy 800,9Cr-lMo steel, and type 316LN stainless steel, in different microstructural conditions were assessed for pitting and stress-corrosion cracking resistances in a chloride medium. The results indicated that 9Cr-lMo steel in the normalized and tempered condition can be considered for the above application from the standpoint of corrosion resistance.

  15. Mechanical analyses of pipeline repair and reinforcement with use of composite functionally graded materials; Analise mecanica de reforco de dutos submarinos com materiais compositos com gradacao funcional

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcos S.M. [Sondotecnica Engenharia de Solos S.A., Rio de Janeiro, RJ (Brazil); Roehl, Deane de Mesquita [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2008-07-01

    This work presents a methodology for design of stiffener sleeve constituted by functionally graded composite materials in offshore pipelines located in extreme-deep waters, where high mechanical resistance allied to an efficient system of thermal isolation is necessary, in view of the excellent thermomechanical behavior of composites. For the case of FGMs, due to continuous variation in its featuring, is necessary to employ an adapted model, based on a model typically adopted for conventional composites (Rule of Mixture), as the model idealized by Tamura, Tomato e Ozawa, the TTO model. In this report, the influence of geometric and materials parameters in mechanical behavior of pipelines under propagating collapse is analyzed. (author)

  16. Change in Selected Characteristics of Students Between Ninth and Twelfth Grade as Related to High School Curriculum.

    Science.gov (United States)

    Strickler, Robert E.

    The research reported in this monograph was conducted as a part of the longitudinal Vocational Development Study (VDS) undertaken by the Department of Vocational Education at Pennsylvania State University. The purpose of this project is to conduct ongoing longitudinal research focused upon uncovering the effects of the senior high school…

  17. Improving the Acquisition and Retention of Science Material by Fifth Grade Students through the Use of Imagery Interventions

    Science.gov (United States)

    Cohen, Marisa T.; Johnson, Helen L.

    2012-01-01

    This study examined the effect of imagery interventions for the presentation of novel science vocabulary to fifth grade learners. Eighty-nine students from two schools in Long Island participated in this study and were randomly assigned to four different instructional interventions: a Picture Presentation method, in which a word was paired with a…

  18. Roman vs. Arabic Computistics in Twelfth-Century England: A Newly Discovered Source (Collatio Compoti Romani et Arabici).

    Science.gov (United States)

    Nothaft, C Philipp E

    2015-01-01

    A frequently overlooked aspect of the knowledge transfer from Arabic into Latin in the twelfth century is the introduction of the Islamo-Arabic calendar, which confronted Western computists with a radically different scheme of lunar reckoning that was in some ways superior to the 19-year lunar cycle of the Roman Church. One of the earliest sources to properly discuss this new system and compare it to the old one is the anonymous Collatio Compoti Romani et Arabici, found in a manuscript from Tewkesbury Abbey, Gloucestershire. This article contains the first edition and translation of this previously unknown text, preceded by an analysis of its content and sources. As will be argued, the text was written in the second quarter of the twelfth century as a reaction to the astronomical tables of al-Khwāizmī, recently translated by Adelard of Bath, as well as to eclipse observations that had exposed the flaws of the 'Roman' computation.

  19. Produksi Functionally Graded Material (FGM dari Hydroxyapatite-Serat Sutra untuk Aplikasi di Bidang Biomaterial dengan Teknik Pulse Electric Current Sintering

    Directory of Open Access Journals (Sweden)

    Tjokorda Gde Tirta Nindhia

    2006-01-01

    Full Text Available This research is intended to produce functionally graded material (FGM of Hydroxyapatite (Hap-silk fibroin by pulse electric current sintering in facing the need in biomaterial application. The sample is created with 4 layers with the thickness for each layer is 0,625 mm, so that the total samples thickness become 2.5mm, with diameter 15 mm. The carbon die is used to compact the sample. The composition of lower layer is 100% silk fibroin, after that 90% silk fibroin +10% Hap, third layer was 80% silk fibroin + 20%Hap, and 70% silk fibroin +30% Hap for the upper layer. The properties of the FGM product was characterized by optical microscope and scanning electron microscope (SEM, three point bend with single-edge beam fracture toughness test (KIC. The grade of the FGM material is proven by using electron probe micro analyzer (EPMA. The value of fracture toughness is 0.45 MPa.m1/2. The sample still can support the load after maximum load is reached. Optical micrograph and SEM, and result from EPMA indicate that the Hap-silk fibroin FGM can be produce perfectly by using the method that is introduced in this research. Abstract in Bahasa Indonesia : Penelitian ini bertujuan memproduksi functionally graded material (FGM dari hydroxyapatite (Hap-serat sutra, melalui teknik pulse electric current sintering untuk memenuhi tantangan kebutuhan akan bahan jenis ini untuk digunakan dibidang biomaterial. Benda uji terdiri dari 4 lapis dengan ketebalan sama untuk tiap lapisnya sehingga tebal total menjadi 2.5 mm dengan diameter 15 mm. Komposisi lapisan paling bawah adalah 100% serat sutra, setelah itu 90% serat sutra + 10% Hap. Lapisan ketiga dengan komposisi 80% serat sutra + 20% Hap, dan 70% serat sutra + 30% Hap untuk lapisan paling atas. Perilaku produk FGM ini dikarakterisasikan dengan mikroskop optik, mikroskop electron, uji ketangguhan retak three point bend with single-edge. Gradasi (grade dari FGM dibuktikan dengan electron probe micro analyzer (EPMA

  20. Thermoelectric properties of p-type (Bi0.15Sb0.85)2Te3-PbTe graded thermoelectric materials with different barriers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The p-type (Bi0.15Sb0.85)2Te3 and PbTe are typical thermoelectric materials used for low and middle temperature range and functional graded materials (FGM) is an inevitable way to widen the working temperature range. Here two segments graded thermoelectric materials (GTM) consisting of (Bi0.15Sb0.85)2Te3, PbTe and different barriers were fabricated by the common hot pressure method. Metals Fe, Mg and Ni were used as barriers between the two segments. The diffusion of different barriers between the barriers and bases were analyzed by electron microprobe analysis (EMA). The phase and crystal structures were determined by X-ray diffraction analysis (XRD). The thermoelectric properties were measured at 303 K along the direction parallel to the pressing direction.The results show that the compositional diffusion occurs when there is no barrier at the interface of the two segments, and the diffusion of Pb is most obvious; as the barrier material, the diffusion of metals Fe, Mg and Ni between different bases is not very obvious,and the thermoelectric properties of GTM is much better than that of the original segment.

  1. Shakespeare revisité, entre fidélité et parodie : de La Nuit des Rois à Shake de Dan Jemmett Shakespeare Revisited, Between Fidelity and Parody: From Twelfth Night to Shake by Dan Jemmett

    Directory of Open Access Journals (Sweden)

    Isabelle Schwartz-Gastine

    2009-11-01

    Full Text Available William Shakespeare himself was a master of re-writing older material as he abundantly used this technique, which was totally justified at the Renaissance, to compose his poems or plays, from various sources whether literary (prose or verse, historical, or any other—and sometimes most unusual—background.The play I am considering in this paper is a very recent re-writing in English by Dan Jemmett (Peter Brook’s son-in-law, but performed in Marie-Paul Remo’s French translation at the Vidy Theatre in Lausanne during the 2001 season. It is called Shake, with a modest sub-title « around Twelfth Night », but which is indeed at the heart of the topic.Through the exploration of three themes: symmetry (of situations, of twin binarities, love’s misunderstanding, and music, I will argue that this comedy, whose title is a mix between the name of the Bard and the etymological meaning of the verb “to shake” as far as traditions are concerned, is faithful to the spirit (rather than the letter of the Shakespearean original in a very healthy comic vein.It is not worth wondering if the spectators fully understood the meaning of this comedy in which the four actors change roles all the time: their frequent bursts of laughter clearly showed that they enjoyed the spirit of the comedy, whether they knew Twelfth Night or not.

  2. Comparison of one-dimensional and two-dimensional functionally graded materials for the backing shell of the cemented acetabular cup.

    Science.gov (United States)

    Hedia, H S

    2005-08-01

    Among the factors that have been suggested as contributing to the failure of a total joint replacement are stress shielding and the subsequent bone resorption. Recent studies have shown that when a backing shell made from a Ti alloy is used, high stresses are generated in the cement at the edges of the cup, and low stresses are generated at the dome of the bone in the acetabulum; thus, the bone at the dome suffers stress shielding and the cement edge suffers high stresses. The aim of this study was to investigate the effect of using a functionally graded material (FGM), instead of Ti alloy, for the backing shell (BS) on the stress distribution in the BS-cement-bone system. Finite-element and optimization techniques were used to obtain the optimal distribution of materials in the tangential direction only of the backing (1D FGM) as well as in the tangential and radial directions of the backing (2D FGM). It was found that the stress distribution in the BS-cement-bone system was about the same, regardless of whether the BS was fabricated from a 1D or 2D FGM. The stress-shielding factor in the bone at the dome of the acetabulum and the maximum von Mises stress in cement at the cement interfaces for 1D and 2D FGM were reduced by about 51%, 69%, and 50%, respectively, compared to the case when the shell was fabricated from a Ti alloy. The optimal elastic modulus of the 1D FGM was obtained with the materials graded from HA at the dome of the acetabulum to a Ti alloy at the rim of the shell. The optimal elastic modulus of the 2D FGM was obtained with the materials graded from Ti alloy at the right edge of the rim, to Bioglass 45S5 at the left edge of the rim, and to HA at the dome of the shell.

  3. Drying of a tape-cast layer: Numerical modelling of the evaporation process in a graded/layered material

    DEFF Research Database (Denmark)

    Jabbaribehnam, Mirmasoud; Jambhekar, V. A.; Hattel, Jesper Henri;

    2016-01-01

    Evaporation of water from a ceramic layer is a key phenomenon in the drying process for the manufacturing of water-based tape cast ceramics. In this paper we present a coupled free-flow-porous-media model on the Representative Elementary Volume (REV) scale for coupling non-isothermal multi...... in accordance with the available results from the literature. We elaborate on and discuss the characteristic drying-rate curve for a single layer ceramic, and compare it with that of a graded/layered ceramic. We, moreover, show the influence of the mean diameter of particles of the porous medium (dp) — which...... directly affects the intrinsic permeability (K) based on the well-known Ergun's equation — of each single ceramic layer on the drying behaviour of a graded/layered ceramic....

  4. Micro-mechanical investigation of the effect of fine content on mechanical behavior of gap graded granular materials using DEM

    Science.gov (United States)

    Taha, Habib; Nguyen, Ngoc-Son; Marot, Didier; Hijazi, Abbas; Abou-Saleh, Khalil

    2017-06-01

    In this paper, we present a micro-mechanical study of the effect of fine content on the behavior of gap graded granular samples by using numerical simulations performed with the Discrete Element Method. Different samples with fine content varied from 0% to 30% are simulated. The role of fine content in reinforcing the granular skeleton and in supporting the external deviatoric stress is then brought into the light.

  5. Hebrew and Latin astrology in the twelfth century: the example of the location of pain.

    Science.gov (United States)

    Burnett, Charles

    2010-06-01

    The formative period of Latin and Hebrew astrology occurred virtually simultaneously in both cultures. In the second quarter of the twelfth century the terminology of the subject was established and the textbooks which became authoritative were written. The responsibility for this lay almost entirely with two scholars: John of Seville for the Latins, and Abraham ibn Ezra for the Jews. It is unlikely to have been by coincidence that the same developments in astrology occurred in these two cultures. John of Seville and Abraham ibn Ezra were both brought up within the Islamic culture of Spain, and their astrology was Arabic astrology. Moreover, some scholars have thought that John's origins were Jewish, while Ibn Ezra is known to have collaborated with Latin scholars (whose names are not recorded). It cannot be a coincidence that they forged the science of astrology for their respect co-religionists at almost the same time. Yet, very little research has been done on the possible relations between the two scholars. The purpose of this paper is to begin to explore this relationship, and to illustrate it in particular by their shared doctrine concern the location of pain.

  6. Stability analysis of axially moving Timoshenko beam made of functionally graded material%轴向运动功能梯度Timoshenko梁稳定性分析

    Institute of Scientific and Technical Information of China (English)

    赵凤群; 王忠民; 路小平

    2014-01-01

    由Hamilton原理建立轴向运动功能梯度Timoshenko梁运动微分方程组,通过引入新未知函数,将方程组化为该函数的四阶偏微分方程。用WDQ(Wavelet Differential Guadreture)法获得简支FGM(Functional Graded Material) Timoshenko梁特征方程及复频率与轴向运动速度变化关系。分析梁随轴向运动速度变化的失稳形式,并与均质材料梁进行比较。分析梯度指标、梁长高比对FGM Timoshenko梁动力稳定性影响。%The governing differential equations of axially moving Timoshenko beam made of functionally graded material were presented based on the Hamilton principle.A single fourth-order partial differential equation was derived by introducing a new unknown function.For simply supported functional graded material (FGM)Timoshenko beam,the characteristic equation was obtained by using wavelet differential guadreture (WDQ)method,and the relation of the first three orders of complex frequencies of the beam with axial movement speed was provided.The instability form of the FGM Timoshenko beam at different axial movement speeds was analyzed in detail,and the results was compared with that of homogeneous material beam.The effects of length-to-height ratio and gradient index on the stability of FGM Timoshenko beam were discussed.

  7. Study of Concentrations of Available Cations and Anions in PM2.5 in the Air of Twelfth Region of Tehran City

    Directory of Open Access Journals (Sweden)

    Hossean Arfaeinia

    2017-04-01

    Full Text Available Background: In the last few decades, the city's air quality has become a major concern; especially there is strong evidence about health effects of particulate matter in urban communities.In addition to suspended particles concentration, the ionic part of suspended particles is also very important, So that some studies  ions like Sulfate is the reson of increasing the respiratory diseases.So the aim of this study was to study of concentration of PM2.5 particles and their ionic componentsincluding major anions and cations in twelfth region of Tehran city in 2013. Materials & Methods: This cross - sectional study was conducted in the air of twelfth region of Tehran. PM2.5 concentration was calculated with sampling by frmOMNITMAmbient Air Sampler with PTFE filter with a diameter of 47 mm and through the weight measurement.Concentration of anions and cations which had associated with PM2.5 particles was read after collected sample preparation and injection to device Ion Chromatography (IC Metrohm 850 model. Correlation matrix was calculated between anions and cations. Data analysis was carried out by Excel and SPSS version 18 and One-Way ANOVA test. Results: The mean daily concentration of PM2.5 particles was 19.41 µg/m3 during the study. One-Way ANOVA test showed a significant difference at the 0.05 level between PM2.5 concentrations on different days of the week. Concentrations for sodium, potassium, ammonium, calcium, magnesium, sulfate, nitrate, chloride were obtained 0.28, 0.06, 0.49, 0.87, 0.63, 56.3, 1.43 and 0.71 µg/m3, respectively, and no value was detected for fluoride and nitrite. Balance between anions and cations were calculated and the correlation coefficient (R2 were obtained 0.972 between the anions and cations. Conclusion The mean concentrations of PM2.5 was higher than the air standards in Iran and WHO guidelines (25 µg/m3 and EPA standards (35 µg/m3. In a study reported that the One-Way ANOVA test between particle

  8. Effect of gradient dielectric coefficient in a functionally graded material (FGM) substrate on the propagation behavior of love waves in an FGM-piezoelectric layered structure.

    Science.gov (United States)

    Cao, Xiaoshan; Shi, Junping; Jin, Feng

    2012-06-01

    The propagation behavior of Love waves in a layered structure that includes a functionally graded material (FGM) substrate carrying a piezoelectric thin film is investigated. Analytical solutions are obtained for both constant and gradient dielectric coefficients in the FGM substrate. Numerical results show that the gradient dielectric coefficient decreases phase velocity in any mode, and the electromechanical coupling factor significantly increases in the first- and secondorder modes. In some modes, the difference in Love waves' phase velocity between these two types of structure might be more than 1%, resulting in significant differences in frequency of the surface acoustic wave devices.

  9. The Insertion of Local Wisdom into Instructional Materials of Bahasa Indonesia for 10th Grade Students in Senior High School

    Science.gov (United States)

    Anggraini, Purwati; Kusniarti, Tuti

    2015-01-01

    This current study aimed at investigating Bahasa Indonesia textbooks with regards to local wisdom issues. The preliminary study was utilized as the basis for developing instructional materials of Bahasa Indonesia that are rich of characters. Bahasa Indonesia instructional materials containing local wisdoms not only equip students with broad…

  10. Rubric for Evaluating Reading/Language Arts Instructional Materials for Kindergarten to Grade 5. REL 2017-219

    Science.gov (United States)

    Foorman, Barbara R.; Smith, Kevin G.; Kosanovich, Marcia L.

    2017-01-01

    The implementation of effective instructional materials, such as a core reading program, by a qualified teacher is an important part of improving students' reading achievement. But selecting those instructional materials can be time-consuming. Regional Educational Laboratory (REL) Southeast created this rubric for evaluating reading/language arts…

  11. Manufacturing Materials and Processes. Grade 11-12. Course #8165 (Semester). Technology Education Course Guide. Industrial Arts/Technology Education.

    Science.gov (United States)

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Vocational Education.

    This guide is intended for use in teaching an introductory course in manufacturing materials and processes. The course centers around four basic materials--metallics, polymers, ceramics, and composites--and seven manufacturing processes--casting, forming, molding, separating, conditioning, assembling, and finishing. Concepts and classifications of…

  12. Optimization of a Functionally Graded Material Stem in the Femoral Component of a Cemented Hip Arthroplasty: Influence of Dimensionality of FGM.

    Science.gov (United States)

    Ait Moussa, Abdellah; Yadav, Rohan

    2017-01-01

    The longevity of hip prostheses is contingent on the stability of the implant within the cavity of the femur bone. The cemented fixation was mostly adopted owing to offering the immediate stability from cement-stem and cement-bone bonding interfaces after implant surgery. Yet cement damage and stress shielding of the bone were proven to adversely affect the lifelong stability of the implant, especially among younger subjects who tend to have an active lifestyle. The geometry and material distribution of the implant can be optimized more efficiently with a three-dimensional realistic design of a functionally graded material (FGM). We report an efficient numerical technique for achieving this objective, for maximum performance stress shielding and the rate of early accumulation of cement damage were concurrently minimized. Results indicated less stress shielding and similar cement damage rates with a 2D-FGM implant compared to 1D-FGM and Titanium alloy implants.

  13. High Heat Flux Testing of B4C/Cu and SiC/Cu Functionally Graded Materials Simulated by Laser and Electron Beam

    Institute of Scientific and Technical Information of China (English)

    刘翔; 谌继明; 张斧; 许增裕; 葛昌纯; 李江涛

    2002-01-01

    B4C, SiC and C, Cu functionally graded-materials (FGMs) have been developed by plasma spraying and hot pressing. Their high-heat flux properties have been investigated by high energy laser and electron beam for the simulation of plasma disruption process of the future fusion reactors, And a study on eroded products of B4C/Cu FGM under transient thermal load of electron beam was performed. In the experiment, SEM and EDS analysis indicated that B4C and SiC were decomposed, carbon was preferentially evaporated under high thermal load, and a part of Si and Cu were melted, in addition, the splash of melted metal and the particle emission of brittle destruction were also found. Different erosive behaviors of carbon-based materials (CBMs) caused by laser and electron beam were also discussed.

  14. The Effect of Different Storage Conditions on the Physical Properties of Pigmented Medical Grade I Silicone Maxillofacial Material

    OpenAIRE

    2013-01-01

    Objective. This study aimed to evaluate the effect of different storage solutions that simulate acidic, alkaline, and sebum conditiions on the physical properties of pigmented (colorant elastomer) cosmesil M511 maxillofacial prosthetic material. Materials and Methods. Sixty specimens were prepared according to the manufacturer's instructions and were tested before and after immersion of different storage conditions for six months at 37 °C. The following tests were performed: color changes (gr...

  15. Functionally Graded Media

    OpenAIRE

    Campos, Cédric M.; Epstein, Marcelo; De León, Manuel

    2007-01-01

    The notions of uniformity and homogeneity of elastic materials are reviewed in terms of Lie groupoids and frame bundles. This framework is also extended to consider the case Functionally Graded Media, which allows us to obtain some homogeneity conditions.

  16. Testing of nuclear grade lubricants and their effects on A540 B24 and A193 B7 bolting materials

    Energy Technology Data Exchange (ETDEWEB)

    Czajkowski, C.J.

    1985-01-01

    An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanical properties of common bolting materials; that MoS/sub 2/ can hydrolyze to form H/sub 2/S at 100/sup 0/C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H/sub 2/O at 280/sup 0/C in notched tensile tests.

  17. Standard test method for analysis of isotopic composition of uranium in nuclear-grade fuel material by quadrupole inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method is applicable to the determination of the isotopic composition of uranium (U) in nuclear-grade fuel material. The following isotopic weight percentages are determined using a quadrupole inductively coupled plasma-mass spectrometer (Q-ICP-MS): 233U, 234U, 235U, 236U, and 238U. The analysis can be performed on various material matrices after acid dissolution and sample dilution into water or dilute nitric (HNO3) acid. These materials include: fuel product, uranium oxide, uranium oxide alloys, uranyl nitrate (UNH) crystals, and solutions. The sample preparation discussed in this test method focuses on fuel product material but may be used for uranium oxide or a uranium oxide alloy. Other preparation techniques may be used and some references are given. Purification of the uranium by anion-exchange extraction is not required for this test method, as it is required by other test methods such as radiochemistry and thermal ionization mass spectroscopy (TIMS). This test method is also described i...

  18. In vivo micronucleus studies with 6 titanium dioxide materials (3 pigment-grade & 3 nanoscale) in orally-exposed rats.

    Science.gov (United States)

    Donner, E M; Myhre, A; Brown, S C; Boatman, R; Warheit, D B

    2016-02-01

    Six pigment-grade (pg) or ultrafine (uf)/nanoscale (anatase and/or rutile) titanium dioxide (TiO2) particulates were evaluated for in vivo genotoxicity (OECD 474 Guidelines) in male and female rats by two different laboratories. All test materials were robustly characterized. The BET surface areas of the pg and uf samples ranged from 7 to 17 m(2)/g and 50 to 82 m(2)/g respectively. The materials were assessed for induction of micronuclei and toxicity in bone marrow by analyzing peripheral blood reticulocytes (RETs) by flow cytometry. Single oral gavage doses of 500, 1000 or 2000 mg/kg body weight (bw) of each material were implemented with concurrent negative (water) and positive controls (cyclophosphamide). Approximately 48 and 72 h after exposure, blood samples were collected and 20,000 RETs per animal were analyzed. For each of the six tests, there were no biologically or toxicologically relevant increases in the micronucleated RET frequency in any TiO2 exposed group at either time point at any dose level. In addition, there were a lack of biologically relevant decreases in %RETs among total erythrocytes. All six TiO2 test substances were negative for in vivo genotoxicity effects; however, it is noted that the exposure to target tissues was likely negligible. One pigment grade and one ultrafine material each were evaluated for potential systemic exposure/uptake from the gastrointestinal tract by analysis of TiO2 into blood and liver. No significant increases in TiO2 over controls were measured in blood (48 or 72 h) or liver (72 h) following exposures to 2000 mg/kg bw TiO2. These data indicate that there was no absorption of the test material from the gastrointestinal tract into the blood circulation and the lack of genotoxic effects is therefore attributed to a lack of exposure due to the inability of the test material to migrate from the gastrointestinal tract into the blood and then into target tissues.

  19. Japanese Culture: Tradition and Change. For Students in Grades Nine through Twelve. Instructional Materials about Japan (IMAJ).

    Science.gov (United States)

    Clark, Ray W.; Reeves, William; Settles, Lois; Sheehan, Valerie Henderson; Spellman, Steve

    This manual provides suggestions and materials for teaching about Japan. Designed as a supplement to typical textbook treatments, the lessons provide a range of readings, visuals, and activities to enrich and deepen student learning about Japan. Organized around topics dealing with history, geography, government, economics, and culture, the…

  20. Government and Politics in Japan. For Students in Grades Nine through Twelve. Instructional Materials about Japan (IMAJ).

    Science.gov (United States)

    Clark, Ray W.; Reeves, William; Settles, Lois; Sheehan, Valerie Henderson; Spellman, Steve

    This manual provides suggestions and materials for teaching about Japan. Designed as a supplement to typical textbook treatments, the lessons provide a range of readings, visuals, and activities to enrich and deepen student learning about Japan. Organized around topics dealing with history, geography, government, economics, and culture, the…

  1. Japan: The Land and Its People. For Students in Grades Six and Seven. Instructional Materials about Japan (IMAJ).

    Science.gov (United States)

    Blankenship, Glen; Edwards, Barbara; Hutchenson, Gwen; Moffitt, Louisa; Ratliff, Penny

    This manual provides suggestions and materials for teaching about Japan. Designed as a supplement to typical textbook treatments, the lessons provide a range of readings, visuals, and activities to enrich and deepen student learning about Japan. Organized around topics dealing with history, geography, government, economics, and culture, the…

  2. Non-local dynamic solution of two parallel cracks in a functionally graded piezoelectric material under harmonic anti-plane shear wave

    Science.gov (United States)

    Liu, Hai-Tao; Sang, Jian-Bing; Zhou, Zhen-Gong

    2016-10-01

    This paper investigates a functionally graded piezoelectric material (FGPM) containing two parallel cracks under harmonic anti-plane shear stress wave based on the non-local theory. The electric permeable boundary condition is considered. To overcome the mathematical difficulty, a one-dimensional non-local kernel is used instead of a two-dimensional one for the dynamic fracture problem to obtain the stress and the electric displacement fields near the crack tips. The problem is formulated through Fourier transform into two pairs of dual-integral equations, in which the unknown variables are jumps of displacements across the crack surfaces. Different from the classical solutions, that the present solution exhibits no stress and electric displacement singularities at the crack tips.

  3. A nonlinear Hermitian transfinite element method for transient behavior analysis of hollow functionally graded cylinders with temperature-dependent materials under thermo-mechanical loads

    Energy Technology Data Exchange (ETDEWEB)

    Shariyat, M. [Faculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)], E-mail: m_shariyat@yahoo.com

    2009-04-15

    In the present paper, an algorithm for nonlinear transient behavior analysis of thick functionally graded cylindrical vessels or pipes with temperature-dependent material properties under thermo-mechanical loads is presented. In contrast to researches presented so far, a Hermitian transfinite element method is proposed to improve the accuracy and to prevent artificial interference or cohesion formation at the mutual boundaries of the elements. Time variations of the temperatures, displacements, and stresses are obtained through a numerical Laplace inversion. Another novelty of the present research is using the transfinite element method to solve nonlinear problems. A sensitivity analysis includes investigating effects of the volume fraction index, dimensions, and temperature-dependency of the material properties is performed. Results confirm the efficiency of the present algorithm and reveal the significant effects of the temperature-dependency of the material properties and the elastic wave reflections and interferences on the responses. In comparison to other techniques, the present technique may be used to obtain relatively accurate and stable results in a less computational time.

  4. Preparation of Functionally Graded Materials (FGMs) Using Coal Fly Ash and NiCr-Based Alloy Powder by Spark Plasma Sintering (SPS)

    Science.gov (United States)

    Kaneko, Gen-yo; Kitagawa, Hiroyuki; Hasezaki, Kazuhiro; Ito, Yuji; Kakuda, Hideaki

    2008-02-01

    Functionally Graded Materials (FGMs) were prepared by spark plasma sintering (SPS) using coal fly ash and NiCr alloy powder. The coal fly ash was produced by the Misumi Coal Thermal Power Station (Chugoku Electric Power Co., Inc.), with 80 wt% nickel and 20 wt% chromium (Fukuda Metal Foil & Powder Co., Ltd.) used as source materials. The sintering temperature in the graphite die was 1000 °C. X-ray diffraction patterns of the sintered coal fly ash materials indicated that mullite (3Al2O3ṡ2SiO2) and silica (SiO2) phases were predominant. Direct joining of coal fly ash and NiCr causes fracture at the interface. This is due to the mismatch in the thermal expansion coefficients (CTE). A crack in the FGM was observed between the two layers with a CTE difference of over 4.86×10-6 K-1, while a crack in the FGM was difficult to detect when the CTE difference was less than 2.77×10-6 K-1.

  5. Experimental Investigation of Effect of Process Parameters on Mrr and Surface Roughness In Turning Operation on Conventional Lathe Machine For Aluminum 6082 Grade Material Using Taguchi Method

    Directory of Open Access Journals (Sweden)

    Mihir T. Patel

    2014-01-01

    Full Text Available In this study, the effect of the machining parameters like spindle speed, feed, depth of cut and nose radius on material removal rate and surface roughness are investigated, also optimum process parameters are studied. An L8 orthogonal array (mixed level design, analysis of variance (ANOVA and the signal –to-noise (S/N ratio are used in this study. Mixed levels of machining parameters are used and experiments are done on conventional lathe machine. Aluminum Alloy - Al 6082 grade material is used in high stress applications, Trusses, Bridges, Cranes, Transport applications, Ore skips, Beer barrels, Milk churns etc. The most significant parameters for material removal rate are speed, depth of cut and least significant factor for MRR is nose radius For surface roughness speed, nose radius are the most significant parameters and least significant factor for surface roughness is depth of cut. The mathematical model obtained as a result of regression analysis can be reliable to predict MRR and surface roughness Ra.

  6. Student’s Misconception of Digestive System Materials in MTs Eight Grade of Malang City and the Role of Teacher’s Pedadogic Competency in MTs

    Directory of Open Access Journals (Sweden)

    Yuswa Istikomayanti

    2017-07-01

    Full Text Available Misconception research has important value in the development of students' thinking processes especially in science field. As the identification of important concepts that must be mastered by the students can be done, the teacher will easily able to emphasis the important or main concepts. This study aims to identify the students’ misconception in digestive system materials in eight grade of MTs and teacher pedagogic competence role. The survey was conducted in 8A (16 students and 8B (17 students MTs Muhammadiyah 1 and 8E (19 students Surya Buana Malang. The stages of research survey were: preparation of research goals (formulation, sample determination, preparation and instruments validation, data collection, and data analysis. The instruments used were: misconception test, student response questionnaire, learning observation guide, and teacher pedagogic competency form. The findings of the learning outcomes were discussed with the observer team, which then were assessed by using the assessment rubric and classified into the categories of student misconceptions. The results showed that the three teachers, neither certified nor uncertified were proved to be limited in overcoming misconceptions in the learning process; meanwhile, the results of students’ misconception test were mostly reach only level 3 (medium. Thus, the study of misconceptions of the digestive system material or other physiological material matter needs to get the attention of the teachers and educational practitioners.

  7. Direct laser metal sintering as a new approach to fabrication of an isoelastic functionally graded material for manufacture of porous titanium dental implants.

    Science.gov (United States)

    Traini, T; Mangano, C; Sammons, R L; Mangano, F; Macchi, A; Piattelli, A

    2008-11-01

    This work focuses on a titanium alloy implants incorporating a gradient of porosity, from the inner core to the outer surface, obtained by laser sintering of metal powder. Surface appearance, microstructure, composition, mechanical properties and fractography were evaluated. All the specimens were prepared by a selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 1-10 microm. The morphological and chemical analyses were performed by SEM and energy dispersive X-ray spectroscopy. The flexure strength was determined by a three-point bend test using a universal testing machine. The surface roughness was investigated using a confocal scanning laser microscope. The surface roughness variation was statistically evaluated by use of a Chi square test. A p value of metal core consisted of columnar beta grains with alpha and beta laths within the grains. The alloy was composed of 90.08% Ti, 5.67% Al and 4.25% V. The Young's modulus of the inner core material was 104+/-7.7 GPa; while that of the outer porous material was 77+/-3.5 GPa. The fracture face showed a dimpled appearance typical of ductile fracture. In conclusion, laser metal sintering proved to be an efficient means of construction of dental implants with a functionally graded material which is better adapted to the elastic properties of the bone. Such implants should minimize stress shielding effects and improve long-term performance.

  8. Satellite NO2 retrievals suggest China has exceeded its NOx reduction goals from the twelfth Five-Year Plan

    Science.gov (United States)

    de Foy, Benjamin; Lu, Zifeng; Streets, David G.

    2016-01-01

    China’s twelfth Five-Year Plan included pollution control measures with a goal of reducing national emissions of nitrogen oxides (NOx) by 10% by 2015 compared with 2010. Multiple linear regression analysis was used on 11-year time series of all nitrogen dioxide (NO2) pixels from the Ozone Monitoring Instrument (OMI) over 18 NO2 hotspots in China. The regression analysis accounted for variations in meteorology, pixel resolution, seasonal effects, weekday variability and year-to-year variability. The NO2 trends suggested that there was an increase in NO2 columns in most areas from 2005 to around 2011 which was followed by a strong decrease continuing through 2015. The satellite results were in good agreement with the annual official NOx emission inventories which were available up until 2014. This shows the value of evaluating trends in emission inventories using satellite retrievals. It further shows that recent control strategies were effective in reducing emissions and that recent economic transformations in China may be having an effect on NO2 columns. Satellite information for 2015 suggests that emissions have continued to decrease since the latest inventories available and have surpassed the goals of the twelfth Five-Year Plan. PMID:27786278

  9. Satellite NO2 retrievals suggest China has exceeded its NOx reduction goals from the twelfth Five-Year Plan.

    Science.gov (United States)

    de Foy, Benjamin; Lu, Zifeng; Streets, David G

    2016-10-27

    China's twelfth Five-Year Plan included pollution control measures with a goal of reducing national emissions of nitrogen oxides (NOx) by 10% by 2015 compared with 2010. Multiple linear regression analysis was used on 11-year time series of all nitrogen dioxide (NO2) pixels from the Ozone Monitoring Instrument (OMI) over 18 NO2 hotspots in China. The regression analysis accounted for variations in meteorology, pixel resolution, seasonal effects, weekday variability and year-to-year variability. The NO2 trends suggested that there was an increase in NO2 columns in most areas from 2005 to around 2011 which was followed by a strong decrease continuing through 2015. The satellite results were in good agreement with the annual official NOx emission inventories which were available up until 2014. This shows the value of evaluating trends in emission inventories using satellite retrievals. It further shows that recent control strategies were effective in reducing emissions and that recent economic transformations in China may be having an effect on NO2 columns. Satellite information for 2015 suggests that emissions have continued to decrease since the latest inventories available and have surpassed the goals of the twelfth Five-Year Plan.

  10. Materials

    Science.gov (United States)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  11. Effects of brewers` condensed solubles (BCS) on the production of ethanol from low-grade starch materials

    Energy Technology Data Exchange (ETDEWEB)

    Choi, C.H.; Chung, D.S.; Seib, P.A. [Kansas State Univ., Manhattan, KS (United States)] [and others

    1995-02-01

    Yeast fermentation was performed on grain and bakery byproducts with and without adding the same volume of brewers` condensed solubles (BCS). Starch material in the grain and bakery byproducts effectively was converted to fermentable sugars with conversion ratios of 93-97% by successive treatments of samples with bacterial {alpha}-amylase and fungal glucoamylase. The yeast fermentation of these enzyme-digested byproducts alone showed that ethanol concentrations of 16.4-42.7 mL/100 g dry solid in the broth were achieved with fermentation efficiencies of 87-96%. Addition of BCS to the grain byproducts increased ethanol concentration by 10-86% by increasing the potential glucose content of the broth. The rates of fermentation measured by CO{sub 2} gas production demonstrated that BCS addition to bakery byproducts reduced the fermentation time from 62-72 h to 34-35 h. In bakery byproducts that were low in amino nitrogen, exhaustion of nitrogenous compounds in substrates was found to be a limiting factor for yeast growth. Because BCS is a rich source of nitrogen, adding BCS to these substrates markedly increased the fermentation rate. 15 refs., 4 figs., 3 tabs.

  12. Elementary Mathematics, Grades 1-6.

    Science.gov (United States)

    Nederland Independent School District, TX.

    GRADES OR AGES: Grades 1-6. SUBJECT MATTER: Elementary math. ORGANIZATION AND PHYSICAL APPEARANCE: Introductory material focuses on the philosophy and objectives of instructional material. The guide is divided into six units covering grades 1-6. Each unit presents the general goals, materials needed, minimum program, skills to be developed,…

  13. 压电功能梯度材料中的SH表面波%SH surface wave in piezoelec-elastic functionally graded materials

    Institute of Scientific and Technical Information of China (English)

    董小峰; 禹建功; 丁俊才

    2011-01-01

    Functionally graded piezoelectric materials (FGPM) have been widely used in SAW devices in order to improve their efficiency and features. The research on surface wave propagation behavior becoming more and more important, in this paper, the propagation behavior of SH surface waves in FGPM is studied. Based on electro-elasticity, the SH wave equation of transversely isotropy piezoelectric-piezomagnetic graded plate is obtained. The Laguerre orthogonal polynomial series expansion approach is employed to derive its solution, and the dispersion curves, displacement curves and electric potential in cases of linear, quadratic and cubic material characteristics variation are obtained. The influence of material constant gradient on the SH wave is investigated and the results have been compared with the ones early.%为了提高声表面波器件的性能,压电功能梯度材料(FGPM)被广泛应用在声表面波(SAW)技术上,因此,压电功能梯度材料中表面波的传播特性研究变得十分重要.研究了压电功能梯度材料中SH(Shear Horizontal)波的传播特性.对于材料特性沿厚度方向为线性函数、二次函数和三次函数变化的三种形式,基于压电-弹性理论,得到了横向各向同性压电功能梯度材料半空间中的SH表面波的控制方程,并利用拉盖尔正交多项式法求得了三种不同特性梯度材料中波的频散曲线、质点位移和电势.与已知的结果比较,证明了这种方法的可行性;并且对不同特性梯度材料中波的特性的比较,研究了材料梯度对SH表面波传播特性的影响.

  14. 功能梯度材料飞轮转子优化设计%Optimum Design of Flywheel Rotor Made of Functionally Graded Materials

    Institute of Scientific and Technical Information of China (English)

    闫晓磊; 钟志华; 查云飞; 莫旭辉; 孙光永

    2011-01-01

    Functionally graded materials(FGMs) are new materials whose properties change continuously in the spatial position.Using FGMs instead of uniform materials for high speed energy storage flywheel rotor can reduce stress concentration effectively and give full play to the material properties, thereby improving the rotor performance.In view of the big error of plane stress(PS) solution when the axial thickness of flywheel rotor is big compared to its radius, a three-dimensional semi-analytical solution that is a modified plane stress(MPS) solution of FGMs flywheel rotor is derived by dividing the rotor into finite ring elements with constant thickness and homogeneous material, and then its accuracy is verified by finite element method.At last, by taking thickness, material volume fraction and rotating speed as design variables, and maximized energy storage density of the rotor as objective function, both shape and material distribution are optimized for FGMs flywheel rotor by using sequential quadratic programming(SQP) method, in addition, the effect of material properties on optimization results are also analyzed.Calculation results indicate that rational shape and material distribution can make stress distribution more even, and greatly increase the energy storage performance of flywheel rotor.%功能梯度材料(Functionally graaed materials,FGMs)是一种材料属性在空间位置上连续变化的新型材料.与均匀材料相比,高速储能飞轮转子采用FGMs可以有效地减少应力集中,充分发挥材料性能,从而改善转子的工作性能.针对飞轮转子轴向厚度相对较厚时平面应力方法误差较大的问题,通过将转子离散为有限个等厚匀质微环的方法,推得变厚度FGMs飞轮转子的三维半解析解--修正平面应力(Modified plane stress,MPS)解,并采用有限元法验证其精确性.应用序列二次规划(Sequential quadratic programming,SQP)优化方法,以飞轮转子的厚度、材料体积分数和

  15. Microstructures of Al-Al3Ti functionally graded materials fabricated by centrifugal solid-particle method and centrifugal in situ method

    Science.gov (United States)

    Watanabe, Yoshimi; Zhou, Qi; Sato, Hisashi; Fujii, Toshiyuki; Inamura, Tomonari

    2017-01-01

    Methods of fabrication by centrifugal casting for functionally graded materials (FGMs) can be classified into two categories on the basis of the relationship between the process temperature and the liquidus temperature of a master alloy. They are the centrifugal solid-particle method and centrifugal in situ method, which could be carried out at process temperatures lower and higher than the liquidus temperature of the master alloy, respectively. In a previous study, it was found that the microstructures of Al-Al3Ti FGMs fabricated by the centrifugal in situ method processed at 1600 °C were different from those fabricated by the centrifugal solid-particle method processed at 800 °C. Although it is expected that the FGMs fabricated by the centrifugal in situ method processed at approximately the liquidus temperature should show extraordinary microstructures, those microstructures have not been observed. In this study, the microstructures of Al-Al3Ti FGMs fabricated at 1000 °C (centrifugal solid-particle method) and 1200 °C (centrifugal in situ method) were investigated.

  16. Fabrication and mechanical properties of Al2O3/SiC/ZrO2 functionally graded material by electrophoretic deposition.

    Science.gov (United States)

    Askari, E; Mehrali, M; Metselaar, I H S C; Kadri, N A; Rahman, Md M

    2012-08-01

    This study describes the synthesis of Al(2)O(3)/SiC/ZrO(2) functionally graded material (FGM) in bio-implants (artificial joints) by electrophoretic deposition (EPD). A suitable suspension that was based on 2-butanone was applied for the EPD of Al(2)O(3)/SiC/ZrO(2), and a pressureless sintering process was applied as a presintering. Hot isostatic pressing (HIP) was used to densify the deposit, with beneficial mechanical properties after 2 h at 1800 °C in Ar atmosphere. The maximum hardness in the outer layer (90 vol.% Al(2)O(3)+10 vol.% SiC) and maximum fracture toughness in the core layer (75 vol.% Al(2)O(3)+10 vol.% SiC + 15 vol.% ZrO(2)) composite were 20.8±0.3 GPa and 8±0.1 MPa m(1/2), respectively. The results, when compared with results from Al(2)O(3)/ZrO(2) FGM, showed that SiC increased the compressive stresses in the outer layers, while the inner layers were under a residual tensile stress.

  17. 用Timoshenko梁修正理论研究功能梯度材料梁的动力响应%Dynamic responses of a beam with functionally graded materials with Timoshenko beam correction theory

    Institute of Scientific and Technical Information of China (English)

    吴晓; 罗佑新

    2011-01-01

    The dynamic response of a beam with functionally graded materials was studied with Timoshenko beam correction theory. The neutral plane site of the beam with functionally graded materials was determined with the static equilibrium equations, and the vibration equations of the beam with functionally graded materials were established with Timoshenko beam correction theory, the expression for the natural frequencies of the beam with functionally graded materials and the analytical solution to forced vibration of the beam under the action of harmonic load were obtained. The effect of neutral plane site and gradient index on the dynamic responses of the beam were discussed, and Timoshenko beam correction theory was verified with finite element method. Analysis of examples indicated that the neutral plane site has larger influence on the dynamic responses of the beam with functionally graded materials.%采用Timoshenko梁修正理论研究了功能梯度材料梁的动力响应问题,利用静力方程确定了功能梯度材料梁的中性轴位置,在此基础上应用Timoshenko梁修正理论建立了功能梯度材料梁的振动方程,求得其自振频率表达式及其在简谐荷载作用下强迫振动的解析解.分析了中性面位置、梯度指数等因素对功能梯度材料梁的动力响应的影响,并用有限元法验证Timoshenko梁修正理论.通过实例计算,得到了中性轴位置对功能梯度材料梁动力响应有较大影响.

  18. Tumor Grade

    Science.gov (United States)

    ... Other Funding Find NCI funding for small business innovation, technology transfer, and contracts Training Cancer Training at ... much of the tumor tissue has normal breast (milk) duct structures Nuclear grade : an evaluation of the ...

  19. Mechanical and physical behavior of newly developed functionally graded materials and composites of stainless steel 316L with calcium silicate and hydroxyapatite.

    Science.gov (United States)

    Ataollahi Oshkour, Azim; Pramanik, Sumit; Mehrali, Mehdi; Yau, Yat Huang; Tarlochan, Faris; Abu Osman, Noor Azuan

    2015-09-01

    This study aimed to investigate the structural, physical and mechanical behavior of composites and functionally graded materials (FGMs) made of stainless steel (SS-316L)/hydroxyapatite (HA) and SS-316L/calcium silicate (CS) employing powder metallurgical solid state sintering. The structural analysis using X-ray diffraction showed that the sintering at high temperature led to the reaction between compounds of the SS-316L and HA, while SS-316L and CS remained intact during the sintering process in composites of SS-316L/CS. A dimensional expansion was found in the composites made of 40 and 50 wt% HA. The minimum shrinkage was emerged in 50 wt% CS composite, while the maximum shrinkage was revealed in samples with pure SS-316L, HA and CS. Compressive mechanical properties of SS-316L/HA decreased sharply with increasing of HA content up to 20 wt% and gradually with CS content up to 50 wt% for SS-316L/CS composites. The mechanical properties of the FGM of SS-316L/HA dropped with increase in temperature, while it was improved for the FGM of SS-316L/CS with temperature enhancement. It has been found that the FGMs emerged a better compressive mechanical properties compared to both the composite systems. Therefore, the SS-316L/CS composites and their FGMs have superior compressive mechanical properties to the SS-316L/HA composites and their FGMs and also the newly developed FGMs of SS-316L/CS with improved mechanical and enhanced gradation in physical and structural properties can potentially be utilized in the components with load-bearing application.

  20. United States Air Force Statistical Digest, Fiscal Year 1957. Twelfth Edition

    Science.gov (United States)

    1957-09-30

    11.2 2.5 10,353 16.~ 41.6 42.0 Interested In AV1.ation R1.d Fl;ying 1,431 97.6 1.6 0.8 2ll ~5.6 38.9 5.5 Securit ;y ~ AF tare 4,464 78.6 16.8 4.6 4,410...1952 THROUGH FY 1957 AGE OROUP GRADE TOTAL 17 2G 2’ ’G " 4G 4, ,G 55’nlrough - _""h - Through Through Through Thro»gh AndI, 24 2’ ," " .. 4, 54 oieee...181 4G 122 7 , 2 1 - - - Airman Third Class 116 59 50 4 2 1 - - - - Airman BasIc J1 15 12 , 1 - - - - - Aviation Cadet 10 - 10 - - - - - - - LAST HALP

  1. Energy drink use is associated with alcohol and substance use in eighth, tenth, and twelfth graders

    Directory of Open Access Journals (Sweden)

    Kathryn Polak

    2016-12-01

    Full Text Available The increasing prevalence of energy drink (ED use and its link with negative behaviors and adverse health outcomes has garnered much attention. Use of EDs combined with alcohol among college students has been of particular interest. It is unclear if these relationships develop in the context of college, or if similar associations exist in younger individuals. The present study examined associations between ED consumption patterns and other substance use in an adolescent, school-based sample. Participants were N = 3743 students attending 8th, 10th or 12th grade in a suburban central Virginia public school system who completed a prevention needs assessment survey in 2012. Chi-square analyses and logistic regressions were used to compare rates of alcohol, tobacco and other drug use across three ED use groups: moderate/heavy (12.6%, light (30.5%, and non-users (57%. Over 40% of the sample reported recent (past month ED use, with males more likely to report moderate/heavy ED use than females (14.0% and 11.1%, respectively; p = 0.02. After adjusting for gender and grade, ED use group predicted lifetime alcohol, tobacco and other drug use (all p < 0.001. Moderate/heavy ED users were most likely and ED non-users were least likely to report using each of the 13 substances in the survey, with light ED users intermediate to the other two groups. Moderate/heavy ED users were consistently most likely to report licit and illicit substance use. Additional research is needed to better understand which adolescents are at greatest risk for adverse health behaviors associated with ED use.

  2. Bypass Flow Computations using a One-Twelfth Symmetric Sector For Normal Operation in a 350 MWth VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Richard W. Johnson; Hiroyuki Sato

    2010-10-01

    Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in their construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are computed by varying the gap width from zero to 5 mm, varying the total heat generation rate to examine average and peak radial generation rates and variation of the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling to the near-gap region. The maximum outlet coolant temperature variation is increased by the presence of gap flow and also by an increase in total heat generation with a gap present. The effect of block shrinkage is actually to decrease maximum fuel temperature compared to a similar reference case.

  3. Bypass Flow Computations using a One-Twelfth Symmetric Sector For Normal Operation in a 350 MWth VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Richard W. Johnson; Hiroyuki Sato

    2012-10-01

    Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in their construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are computed by varying the gap width from zero to 5 mm, varying the total heat generation rate to examine average and peak radial generation rates and variation of the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling to the near-gap region. The maximum outlet coolant temperature variation is increased by the presence of gap flow and also by an increase in total heat generation with a gap present. The effect of block shrinkage is actually to decrease maximum fuel temperature compared to a similar reference case.

  4. Developmental toxicity studies with 6 forms of titanium dioxide test materials (3 pigment-different grade & 3 nanoscale) demonstrate an absence of effects in orally-exposed rats.

    Science.gov (United States)

    Warheit, D B; Boatman, R; Brown, S C

    2015-12-01

    Six different commercial forms and sizes of titanium dioxide particles were tested in separate developmental toxicity assays. The three pigment-grade (pg) or 3 ultrafine (uf)/nanoscale (anatase and/or rutile) titanium dioxide (TiO2) particle-types were evaluated for potential maternal and developmental toxicity in pregnant rats by two different laboratories. All studies were conducted according to OECD Guideline 414 (Prenatal Developmental Toxicity Study). In addition, all test materials were robustly characterized. The BET surface areas of the pg and uf samples ranged from 7 to 17 m(2)/g and 50-82 m(2)/g respectively (see Table 1). The test substances were formulated in sterile water. In all of the studies, the formulations were administered by oral gavage to time-mated rats daily beginning around the time of implantation and continuing until the day prior to expected parturition. In 3 of the studies (uf-1, uf-3, & pg-1), the formulations were administered to Crl:CD(SD) rats beginning on gestation day (GD) 6 through GD 20. In 3 additional studies (uf-2, and pg-2, pg-3 TiO2 particles), the formulations were administered to Wistar rats beginning on GD 5 through 19. The dose levels used in all studies were 0, 100, 300, or 1000 mg/kg/day; control group animals were administered the vehicle. During the in-life portions of the studies, body weights, food consumption, and clinical observations before and after dosing were collected on a daily basis. All dams were euthanized just prior to expected parturition (GD 21 for Crl:CD(SD) rats and GD 20 for Wistar rats). The gross necropsies included an examination and description of uterine contents including counts of corpora lutea, implantation sites, resorptions, and live and dead fetuses. All live fetuses were sexed, weighed, and examined externally and euthanized. Following euthanasia, fresh visceral and head examinations were performed on selected fetuses. The fetal carcasses were then processed and examined for skeletal

  5. U.S. Energy Policy -- Which Direction? Grades 11 and 12. Interdisciplinary Student/Teacher Materials in Energy, the Environment, and the Economy.

    Science.gov (United States)

    National Science Teachers Association, Washington, DC.

    This instructional unit for use in 11th and 12th grade social studies and science courses contains six classroom lessons dealing with United States energy policy. The overall objective is to help students understand how circumstances, present and proposed legislation, political action, and the Constitution itself become linked in the development…

  6. Materialien und Modelle fuer den Franzoesischunterricht in der Sekundarstufe Zwei (Materials and Models for Teaching French in Grades 11-13)

    Science.gov (United States)

    Frei, Alfons

    1978-01-01

    Texts available for French courses in the highest grades are listed according to topics, which include: position of women, today's youth, the language of advertising, French colonialism, holidays and tourism, modern city living, criminality, French politics. Hints for the teacher are included. (Text is in German.) (IFS/WGA)

  7. Functionally Graded Mo sintered steels

    Directory of Open Access Journals (Sweden)

    Manuel Cisneros-Belmonte

    2016-12-01

    Full Text Available Functionally graded materials (FGM, the multi-materials, strive to satisfy the numerous requirements demanded of parts in a given combination of compositions and microstructures. The required material compatibility lead the manufacturing process and the achieving of an interface, not always diffuse. Powder metallurgy is one of the techniques used in manufacturing functionally graded materials, in particular the compaction matrix of the possible techniques for forming these materials. In this paper, a process of forming a functionally graded steel based on the use of a high molybdenum steel with cooper and other steel with copper, without molybdenum, is proposed with the aim of concentrating this element to the surface of the workpiece, increasing the mechanical strength. The study is completed with the evaluation of physical properties (density and porosity distribution, mechanical properties (hardness, tensile strength and elongation and microstructural analysis by optical and scanning electron microscopy.

  8. RESEARCH AND DEVELOPMENT OF QIAOXING GRADE A1 INCOMBUSTIBLE HEAT INSULATING MATERIAL AND ITS PRODUCTS%侨兴A1级不燃保温材料及制品的研发

    Institute of Scientific and Technical Information of China (English)

    龙文志

    2011-01-01

    The independently innovated and developed Qiaoxing grade A1 incombustible heat insulating material is a kind of external heat insulating material on external wall, having excellent "incombustible, heat insulating, environmentally-friendly and economic" characteristics. This material and its products successfully solve the fireproof and heat insulation problem of high-rise building. The development of Qiaoxing grade A1 incombustible heat insulating material and its products are still in the preliminary phase and more efforts shall be made for further development and promotion in the future.%通过自主创新研发的侨兴A1级不燃保温材料和制品是具有“不燃、保温、环保、经济”四性皆优的外墙外保温材料,解决了高层建筑既防火又保温这一难题.侨兴A1级不燃保温材料和制品开发尚刚起步,今后发展、推广还需继续加强和努力.

  9. Fiscal transfers based on inputs or outcomes? Lessons from the Twelfth and Thirteenth Finance Commission in India.

    Science.gov (United States)

    Fan, Victoria Y; Iyer, Smriti; Kapur, Avani; Mahbub, Rifaiyat; Mukherjee, Anit

    2017-08-30

    There is limited empirical evidence about the efficacy of fiscal transfers for a specific purpose, including for health which represents an important source of funds for the delivery of public services especially in large populous countries such as India. To examine two distinct methodologies for allocating specific-purpose centre-to-state transfers, one using an input-based formula focused on equity and the other using an outcome-based formula focused on performance. We examine the Twelfth Finance Commission (12FC)'s use of Equalization Grants for Health (EGH) as an input-based formula and the Thirteenth Finance Commission (13FC)'s use of Incentive Grants for Health (IGH) as an outcome-based formula. We simulate and replicate the allocation of these two transfer methodologies and examine the consequences of these fiscal transfer mechanisms. The EGH placed conditions for releasing funds, but states varied in their ability to meet those conditions, and hence their allocations varied, eg, Madhya Pradesh received 100% and Odisha 67% of its expected allocation. Due to the design of the IGH formula, IGH allocations were unequally distributed and highly concentrated in 4 states (Manipur, Sikkim, Tamil Nadu, Nagaland), which received over half the national IGH allocation. The EGH had limited impact in achieving equalization, whereas the IGH rewards were concentrated in states which were already doing better. Greater transparency and accountability of centre-to-state allocations and specifically their methodologies are needed to ensure that allocation objectives are aligned to performance. © 2017 The Authors. The International Journal of Health Planning and Management published by John Wiley & Sons Ltd.

  10. Bypass flow computations using a one-twelfth symmetric sector for normal operation in a 350 MWth prismatic VHTR

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Richard W., E-mail: rich.johnson@inl.gov [Idaho National Laboratory, P.O. Box 1625, M.S. 3855, Idaho Falls, ID (United States); Sato, Hiroyuki, E-mail: sato.hiroyuki09@jaea.go.jp [Idaho National Laboratory, P.O. Box 1625, M.S. 3855, Idaho Falls, ID (United States)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer CFD calculations are made of bypass flow between graphite blocks in VHTR. Black-Right-Pointing-Pointer Parameters varied include bypass gap width, heat generation and geometry. Black-Right-Pointing-Pointer Bypass flow causes lateral temperature gradients in graphite block. Black-Right-Pointing-Pointer Bypass flow causes increases in max fuel and coolant temperatures. Black-Right-Pointing-Pointer Bypass flow causes large increase in outlet coolant temperature variation - Abstract: Significant uncertainty exists about the effects of bypass flow in a prismatic gas-cooled very high temperature reactor (VHTR). Bypass flow is the flow in the gaps between prismatic graphite blocks in the core. The gaps are present because of variations in graphite block construction, imperfect installation and expansion and shrinkage from thermal heating and neutron fluence. Calculations are performed using computational fluid dynamics (CFD) for flow of the helium coolant in the gap and coolant channels along with conjugate heat generation and heat transfer in the fuel compacts and core graphite. A commercial CFD code is used for all of the computations. A one-twelfth sector of a standard hexagonal block column is used for the CFD model because of its symmetry. Various scenarios are investigated including varying the gap width, varying the total heat generation between average and peak rates and varying the graphite block geometry to account for the effects of shrinkage caused by irradiation. The calculations are for a 350 MWth prismatic reactor. It is shown that the effect of increasing gap width, while maintaining the same total mass flow rate, causes increased maximum fuel temperature while providing significant cooling to the near-gap region. The maximum outlet coolant temperature variation is increased by the presence of gap flow and also by an increase in total heat generation. The effect of block shrinkage is actually to decrease maximum

  11. An exploratory curriculum analysis of thirteen virtual schools, online homeschools and online curriculum providers' science curriculum from kindergarten through twelfth grade

    Science.gov (United States)

    Jones, Dussy L.

    2007-12-01

    The purpose of this study is to describe and examine various Internet-based science curricula in terms of their educational value and comprehensiveness. Thirteen online homeschool providers' science curricula were analyzed through an examination of the content and organization of instruction and through a comparison with the seven National Science Education Standards (NSES) in order to assess the pedagogical and developmental appropriateness of online science curriculum, to find the ideological perspectives exhibited by each curriculum, and to identify implications for the future of homeschooling regarding children who use an online science curriculum as the basis of their science education. The results reveal that only a few online schools incorporate all seven NSES in their science curriculum; most online schools' content and instruction have a traditional/behavioral perspective; and the Systematizer theoretical perspective was prevalent in online schools' science curricula. This study investigates the issue of whether online homeschooling can accurately be termed homeschooling. A discussion of education and schooling according to Holt (1976), Illich (1972), and Moore and Moore (1975) explore this issue. The findings from this discussion suggest that the online homeschool movement may be an undiscovered form of "schooling" and that parents, educators, researchers, curriculum developers, and specialists should be aware of the implications online homeschooling has on homeschooling's philosophy of education.

  12. Use of photography to support the learning process of science teachers of ninth through twelfth grades in the schools of Kuwait

    Science.gov (United States)

    Alenizi, Abdulaziz

    The purpose of the study was to investigate the relevance of teachers in Kuwait when utilizing photographic aids in the classroom. Specifically, this study assessed learning outcomes of teachers amongst high school students in schools at Kuwait. The learning outcomes were then compared with teachers who are barred from using photographic aids. The research utilized a descriptive quantitative research design. The number of participants was limited to an acceptable number in the range of 250--300. Data were collected through a questionnaire and analyses were conducted using various types of statistical designs for interpretation, specifically Spearman correlation analysis. The study revealed that visual media such as images and photographs made it easy for the students to understand the concepts of science subjects, specifically biology, physics, and chemistry. Visual media should be included in the curriculum to enhance the comprehension level of students. The government of Kuwaiti, therefore, should to encourage the use of visual aids in schools to enhance learning. The research did not indicate a capacity of skills students and teachers can employ effectively when using visual aids. There also remains a gap between possessing the skills and applying them in the school. Benefits associated with visuals aids in teaching are evident in the study. With the adoption of audio-visual methods of learning, students are presented with opportunities to develop their own ideas and opinions, thus boosting their own interpersonal skills while at the same time questioning the authenticity and relevance of the concepts at hand. The major merit of audio-visual platforms in classroom learning is they cause students to break complex science concepts into finer components that can be easily understood.

  13. Know the Code. Twelfth Grade--Principles of American Democracy Lesson. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    MacDonald, David R.

    In response to campus crime schools across the United States have instituted rigorous dress codes, and, in some cases, have required students to wear uniforms to school. The president of the local school board has received petitions from several groups wishing to speak at the next school board meeting. The president's political survival rests upon…

  14. Which Country Will Make You the Most Money? Ninth-Twelfth Grade Activity. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    Drieberg, Denver

    Foreign Currency Exchange is the largest business in the world. The New York Institute of Finance estimates that somewhere around 1.5 trillion dollars changes hands every 24 hours. The trading of international currencies has made overnight millionaires. No other marketplace in the world can give a person more significant opportunity to make money…

  15. Pedal Power Goes Global. Twelfth Grade Economics Lesson Plan. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    Antillas, Madeline

    Many factors must be considered when a company decides to market its product in another country. It must research the targeted country to determine if there is a demand for the product, decide on product modifications needed to match the new market, and develop a plan to market and distribute the product in this new business environment. In this…

  16. The Bill of Rights. Twelfth Grade--Principles of American Democracy Lesson. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.

    Science.gov (United States)

    Houghton, Robert

    When George Washington was sworn in as the first President of the United States on April 30, 1789, the U.S. Constitution had already been ratified, yet the future of the new country was at risk. Some people wanted a bill of rights added to the U.S. Constitution to guarantee individual liberties. Two groups opposed each other--the Federalists…

  17. A summary of the Proceedings of the Twelfth International Symposium on the Neurobiology and Neuroendocrinology of Aging, Bregenz, Austria July 27-August 1, 2014.

    Science.gov (United States)

    Brown-Borg, Holly M; Borg, Kurt E

    2015-08-01

    A summary of the Twelfth International Symposium on the Neurobiology and Neuroendocrinology of Aging that was held July 27-August 1, 2014 in Bregenz, Austria, is presented. Fifteen of the speakers that presented at the conference submitted review papers covering the topic of their presentation as well as an overview of their respective fields and are included in this special issue. The abstracts from each poster presentation as well as seven of the speakers' abstracts are also included at the end of the preface to the special issue.

  18. Aerospace Grade Carbon Felt Preform Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fiber Materials, Inc. (FMI) will develop an aerospace-grade carbon felt preform by employing application specific materials with effective processes and fabrication...

  19. Improving Grading Consistency through Grade Lift Reporting

    Science.gov (United States)

    Millet, Ido

    2010-01-01

    We define Grade Lift as the difference between average class grade and average cumulative class GPA. This metric provides an assessment of how lenient the grading was for a given course. In 2006, we started providing faculty members individualized Grade Lift reports reflecting their position relative to an anonymously plotted school-wide…

  20. Report on the results of the twelfth medical examination of atomic bomb survivors residing in North America

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yasuji [Hiroshima Prefectural Medical Association (Japan); Ohama, Koso; Fujiwara, Saeko (and others)

    2000-06-01

    The twelfth medical examination of atomic bomb survivors residing in North America, was conducted in San Francisco and Seattle from May 20 through June 2 1999, and in Los Angeles and Hawaii from June 9 through 23 1999, The examination included an interview, measurement of height, weight, and blood pressure, an ECG, urine and stool tests, blood tests, a physical examination, examination of the breast, thyroid, and rectum by a surgeon, and screening for uterine cancer and a gynecological interview and examination by an obstetrician and gynecologist. The total confirmed number of A-bomb survivors residing in North America as of the end of June 1999 was 1076. Of the 1062 survivors that remained after excluding the 14 subjects whose survey was incomplete, 279 males and 654 females had been exposed in Hiroshima, and 10 males and 119 females in Nagasaki. The peak age at the time of exposure in both sexes was 15-19 years, followed by 10-14 years. The number of survivors exposed <2000 m from the hypocenter was 236, accounting for 21.9% of the total. The confirmed number of survivors exposed in utero was 26. The survivors' age (mean {+-}S.D.) was: 69.0{+-}8.69 years; males, 68.4{+-}80.5 years; females, 69.2{+-}8.91 years. A total of 414 survivors were examined (male 129; female 285; mean age 68.0 years). Approximately 80% of the examinees had experienced at least one general symptom. Many still complain of symptoms that suggest possible posttraumatic stress disorder as a result of exposure to the A-bomb. It will be necessary to consider providing mental health care by psychiatrists beginning with the next examination. The prevalence of life-style diseases has been gradually increased with age. A previous history of cancer was found in 9.2% of the examinees. The most prevalent was of breast cancer, followed by malignant tumors of the colon, rectum, uterus, brain, stomach, and thyroid. The need for cancer screening and promotion of life-style education was keenly felt. (K.H.)

  1. Construction of sequences of exact analytical solutions for heat diffusion in graded heterogeneous materials by the Darboux transformation method. Examples for half-space

    Science.gov (United States)

    Krapez, J.-C.

    2016-09-01

    The Darboux transformation is a differential transformation which, like other related methods (supersymmetry quantum mechanics-SUSYQM, factorization method) allows generating sequences of solvable potentials for the stationary 1D Schrodinger equation. It was recently shown that the heat equation in graded heterogeneous media, after a Liouville transformation, reduces to a pair of Schrödinger equations sharing the same potential function, one for the transformed temperature and one for the square root of effusivity. Repeated joint PROperty and Field Darboux Transformations (PROFIDT method) then yield two sequences of solutions: one of new solvable effusivity profiles and one of the corresponding temperature fields. In this paper we present and discuss the outcome in the case of a graded half-space domain. The interest in this methodology is that it provides closed-form solutions based on elementary functions. They are thus easily amenable to an implementation in an inversion process aimed, for example, at retrieving a subsurface effusivity profile from a modulated or transient surface temperature measurement (photothermal characterization).

  2. Probing the Efficientway of Writing into the Eight Grade Language Material Composition%八年级语文材料作文的高效写作方式探究

    Institute of Scientific and Technical Information of China (English)

    邓清幼

    2014-01-01

    材料作文通过文字资料或图画的形式呈现写作主题,目的是培养学生良好的总结能力和想象能力。将从八年级语文材料作文写作中存在的问题和如何探索高效写作方式来具体论述。%Through the material composition of written information or pictures in the form of writing subject,the purpose is to cultivate students good summary of skills and the ability to imagine. It will from grade eight Chinese problems existing in the material composition writing and how to explore the efficient way of writing paper.

  3. SIMULATION AND OPTIMIZATION OF THERMAL RESIDUAL STRESS IN COATING STRUCTURE WITH FUNCTIONALLY GRADED MATERIAL LAYER%含FGM的涂层结构中热残余应力的分析与优化

    Institute of Scientific and Technical Information of China (English)

    张榕京; 黄晨光; 段祝平

    2001-01-01

    An elasto-plastic finite element method is developed to predict the thermal residual stress of thermal spraying coatings with functionally graded material (FGM) layer. The optimized distribution form and parameter p about the volume fractions of various constituents in the FGM are obtained by the first order optimization method in the AL2O3 -Ni model system. The effects of geometry and material behavior on the optimization results are investigated numerically, including the temperature sensitivity of FGM and substrate material. It is found that the optimization of the constituent contents in FGM reduces the magnitude of residual stresses to a large degree. And the maximum residual stresses shun the weakest part of the coating structure by the optimization designing. When the length of specimen, the thickness of FGM layer and the thermal expansion coefficient of the substrate increase, while the distribution parameter p decreases. The results presented in this paper are useful for the design of thermal spraying coatings.%本文利用有限元方法和优化理论,对含FGM(Functionally Graded Materials)层的热喷涂构件中的残余应力进行了数值分析,并获得了FGM内各组份体积含量分布的最优化形式和参数p。同时,我们也研究了喷涂构件的几何形状、涂层及基底的材料性能对于p的影响规律。在本文的分析中,考虑了基底材料和FGM的塑性变形以及其性能对于温度的依赖。本文的工作将有利于含FGM层的热喷涂构件的设计与生产。

  4. 聚变堆第一壁连续W/Cu梯度材料的热工性能优化%Thermo-technical performance optimization on first wall in fusion reactor applied with continuous W/Cu functionally graded material

    Institute of Scientific and Technical Information of China (English)

    赵永强; 黄生洪; 汪卫华

    2016-01-01

    针对不同体积分布指数p的W/Cu连续功能梯度材料的偏滤器第一壁结构,采用有限元软件计算了8MW.m−2稳态运行热加载以及等离子体破裂条件下1GW.m−2热流冲击下的力学响应。相同稳态加载条件下,W/Cu连续功能梯度材料的最优分布指数与分层梯度材料存在较大差异,其最优等效应力比分层梯度材料要小26%,表现出更优异的性能。在热冲击响应过程中,连续梯度W/Cu材料塑性损伤随p值不同也存在较大变化,其最优p值与其稳态运行时热应力最优p值存在一定差异,从第一壁应用条件考虑,应综合选取,最佳p值在1.2附近。综合来看,连续梯度W/Cu材料具有更连续变化的热物理属性及力学性能,在聚变堆第一壁结构设计中具有更大的应用潜力。%The thermo-technical performance optimization on first wall in fusion reactor made by such continuous W/Cu graded material with different composition distribution parameterp was descrided The thermal/mechanical responses of the first wall mockup under steady-state heat loads of 8MW.m−2and heat shock loads of 1GW.m−2during plasma disruptions are computed numerically with the finite element method. Under the same steady heat load conditions, the optimized composition distribution parameterp for composition continuous W/Cu graded material is very different with that of previous quasi-continuous W/Cu graded material. A 26%reducing in thermal stress is observed for first wall with composition continuous W/Cu graded material, demonstrating a more excellent performance. In the process of heat shock, the damage degree measured by volume fraction of plastic deformation is changing with different composition distribution parameterp, its optimized value is different with that obtained in steady state conditions. In consideration of environment conditions endured by first wall, the optimized value should be chosen to be close to 1.2. In general

  5. The Influence of Al2O3 Powder Morphology on the Properties of Cu-Al2O3 Composites Designed for Functionally Graded Materials (FGM)

    Science.gov (United States)

    Strojny-Nędza, Agata; Pietrzak, Katarzyna; Węglewski, Witold

    2016-08-01

    In order to meet the requirements of an increased efficiency applying to modern devices and in more general terms science and technology, it is necessary to develop new materials. Combining various types of materials (such as metals and ceramics) and developing composite materials seem to be suitable solutions. One of the most interesting materials includes Cu-Al2O3 composite and gradient materials (FGMs). Due to their potential properties, copper-alumina composites could be used in aerospace industry as rocket thrusters and components in aircraft engines. The main challenge posed by copper matrix composites reinforced by aluminum oxide particles is obtaining the uniform structure with no residual porosity (existing within the area of the ceramic phase). In the present paper, Cu-Al2O3 composites (also in a gradient form) with 1, 3, and 5 vol.% of aluminum oxide were fabricated by the hot pressing and spark plasma sintering methods. Two forms of aluminum oxide (αAl2O3 powder and electrocorundum) were used as a reinforcement. Microstructural investigations revealed that near fully dense materials with low porosity and a clear interface between the metal matrix and ceramics were obtained in the case of the SPS method. In this paper, the properties (mechanical, thermal, and tribological) of composite materials were also collected and compared. Technological tests were preceded by finite element method analyses of thermal stresses generated in the gradient structure, and additionally, the role of porosity in the formation process of composite properties was modeled. Based on the said modeling, technological conditions for obtaining FGMs were proposed.

  6. 浅谈现代医院物资供应链中二级库管理%Grade Ⅱ Storehouse Management in Material Supply Chains of the Modern Hospital

    Institute of Scientific and Technical Information of China (English)

    李维嘉; 张雷; 钱建国; 吴正灏

    2016-01-01

    The promotion of Grade Ⅱ storehouse in the hospital makes the management of products supply chain more perfect and realizes full-round tracking from the warehouse to the department and from the department to the patient, which provided a powerful data support for accounting management. The function of the Grade Ⅱ storehouse adopted modular design, including department requirement management, Grade Ⅱ storehouse management, comprehensive business queries, statistics report, and basic data maintenance. Moreover, personalized management of Grade Ⅱ storehouse was realized and code management, intelligent reminder function and integration of multi-system interface was developed according to different clinical requirements. In order to realize the medical products elaborating management and zero inventory, modern methods and Grade Ⅱ storehouse management should be adopted to continuously optimize the material supply chain.%二级库管理的推广使得医院在物资供应链上的管理更加全面,完成了从库房到科室、从科室到病人的全跟踪。为核算管理提供了有力的数据支持。二级库管理系统的功能采用模块化设计,包括科室需求管理、二级库管理、综合业务查询、报表统计、基础数据维护。此外实现二级库个性化管理,根据不同临床需求开发一物一码管理、智能化提醒功能和多系统界面整合。用现代化手段和二级库管理不断优化物资供应链,实现医疗物资精细化管理、“零库存”目标。

  7. Cytological grading of breast carcinoma on fine needle aspirates and its relation with histological grading

    Directory of Open Access Journals (Sweden)

    Jyoti Prakash Phukan

    2015-01-01

    Full Text Available Background: Grading of breast carcinoma on fine needle aspiration cytology (FNAC is beneficial for selecting patients for neoadjuvant chemotherapy. Aims: To grade the breast carcinoma on FNAC using Robinson grading system and to assess the concordance of cytological grading (CG with histological grading (HG using Elston-Ellis modification of Scarff-Bloom-Richardson grading system. Materials and Methods: The study was conducted for 1-year, comprising of 50 female patients attending outpatient departments (OPD as well as admitted in various surgical wards of a teaching hospital, diagnosed as breast carcinoma. FNAC smears were stained with May-Grunwald-Giemsa and Papanicolaou (Pap stains and CG was done using Robinson system on Pap stained smears. The results were compared with HG system after resection of tumors. Results: Of 50 cases, 14 (28% cases were graded as grade I, 24 (48% grade II, and 12 (24% grade III by CG, whereas 9 (18%, 28 (56% and 13 (26% cases were graded as grade I, II and III by HG. The result showed overall 72% concordance of CG with HG, with grade II and grade III showing highest degree of concordance (83.33%, which is comparable to previous studies. Kappa measurement showed a higher degree of agreement in high-grade tumors compared with low-grade tumors (0.73 in grade III, 0.53 in grade II and 0.39 in grade I. Conclusion: Cytological grading is comparable to HG in majority of cases. Because neoadjuvant chemotherapy is becoming increasingly popular as primary treatment modality of breast cancer, CG could be a useful parameter in selecting the mode of therapy and predicting tumor behavior.

  8. Multi-Objective Optimization ( Surface Roughness & Material Removal Rate of Aisi 202 Grade Stainless Steel in Cnc Turning Using Extended Taguchi Method And Grey Analysis

    Directory of Open Access Journals (Sweden)

    Er.Ankush Aggarwal

    2014-07-01

    Full Text Available The present study applied Taguchi method through a case study in straight turning of AISI 202 stainless steel bar on CNC Machine ( Mfd by ACE DESIGNERS using Titanium Carbide tool for the optimization of Material removal rate, Surface Roughness and tool wear process parameter.The study aimed at evaluating the best process environment which could simultaneously satisfy requirements of both quality as well as productivity with special emphasis on maximizing material removal rate and minimizing surface roughness and tool flank wear at various combination of cutting speed, feed, depth of cut. The predicted optimal setting ensured maximum MRR and minimum surface roughness and tool wear. Since optimum material removal rate is desired, so higher the better criteria of Taguchi signal to noise ratio is used for MRR – SNs = -10 log(Sy2 /n

  9. Study on the thermal conductivity of diamond-like carbon functionally graded material on copper substrate%铜基类金刚石膜功能梯度材料作为散热材料的研究

    Institute of Scientific and Technical Information of China (English)

    王静; 刘贵昌; 李红玲; 侯保荣

    2012-01-01

    随着电子技术、信息产业的发展,Cu在微型散热材料、电子封装材料上应用日益广泛.Cu在应用过程中存在强度低、易氧化、易磨损等缺点.采用等离子体复合沉积技术,在铜基体上制备了Ti/TiC/DLC功能梯度材料,改善铜基体与美金刚石(DLC)膜的结合力,强化了铜的机械性能.瞬态热反射法检测结果表明,DLC功能梯度材料不会影响铜基体的散热效果.%In recent years, with the rapid development of electronic technology and digital network information, copper has increasing applications in micro-electronics, micro-electro-mechanical systems and Hi-tech materials. However copper has its material limitations. In particular, it has relatively low hardness, high oxidation and wear rate, which have severely restricted its widespread applications. In this paper, aiming at difficulties of copper applications, Ti/TiC/DLC has been proposed as functionally graded material to deposit on the copper substrate with plasma depositing method, which intensifies the adhesion between DLC film and copper substrate and improves the properties of copper. The maximal value of thermal conductivity of DLC film with optimized parameter of graded intermediate layer is 3.63 Wm-1.K-1, which enhances the heat transfer effect of copper substrate.

  10. Graded Density Carbon Bonded Carbon Fiber (CBCF) Preforms for Lightweight Ablative Thermal Protection Systems (TPS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — FMI has developed graded density CBCF preforms for graded density phenolic impregnated carbon ablator (PICA) material to meet NASA's future exploration mission...

  11. Cytological grading of breast cancers and comparative evaluation of two grading systems

    Directory of Open Access Journals (Sweden)

    Wani Farooq

    2010-01-01

    Full Text Available Aim: To evaluate and compare the cytograding of breast cancers using Robinson′s and Mouriquand′s grading methods. Materials and Methods: A 5-year retrospective (from Oct 2000 to Sept 2005 and 1-year prospective study (from Oct 2005 to Oct 2006. A total of 110 fine-needle aspiration cytology (FNAC cases of breast cancers were studied. These were graded according to Robinson′s and Mouriquand′s grading methods (grade I-III followed by comparison of the two methods. Results: Of the 110 cases graded according to Robinson′s method, 28 (25.45% cases were grade I, 46 (41.81% grade II, and 36 (32.72% were grade III, whereas using Mouriquand′s grading methods, 28 (25.45%, 42 (38.18%, and 40 (36.36% cases were graded as grade I, II, and III, respectively. A high degree of concordance was observed between the two grading methods (90.9%. A highly significant relationship between the scores obtained by two methods was also observed (P=0.004. Conclusions: A comprehensive cytological grading of breast cancers is possible by using two different methods proposed by Robinson and Mouriquand. In spite of a high degree of concordance between the two methods, the Robinson′s grading system has been found to be easier and better because of more objective set of criteria and easy reproducibility.

  12. Decreased group velocity in compositionally graded films.

    Science.gov (United States)

    Gao, Lei

    2006-03-01

    A theoretical formalism is presented that describes the group velocity of electromagnetic signals in compositionally graded films. The theory is first based on effective medium approximation or the Maxwell-Garnett approximation to obtain the equivalent dielectric function in a z slice. Then the effective dielectric tensor of the graded film is directly determined, and the group velocities for ordinary and extraordinary waves in the film are derived. It is found that the group velocity is sensitively dependent on the graded profile. For a power-law graded profile f(x)=ax(m), increasing m results in the decreased extraordinary group velocity. Such a decreased tendency becomes significant when the incident angle increases. Therefore the group velocity in compositionally graded films can be effectively decreased by our suitable adjustment of the total volume fraction, the graded profile, and the incident angle. As a result, the compositionally graded films may serve as candidate material for realizing small group velocity.

  13. Mechanics of Graded Wrinkles

    Science.gov (United States)

    Raayai-Ardakani, Shabnam; Boyce, Mary

    2013-03-01

    Shark skin is known for its anti-fouling and self-cleaning properties. In attempts to mimic this pattern for getting similar properties, different surface patterns such as Sharklet and wrinkles have been previously introduced. Wrinkled patterns have gained importance in applications such as microfluidics, wetting and adhesion. Through buckling of a thin film of stiff material on a substrate of softer material, and maintaining symmetric geometries, ordered wrinkled patterns can be created. However, it can be shown that using the same principle, by changing the geometry of the surface, the dimensions of the wrinkles can be altered. This alteration turns ordered wrinkles into graded wrinkles which have more resemblance to shark skin than the ordered wrinkles, maintaining the same wave length while each wave having different amplitude. Here using finite element models, experiments and analytical solutions, the relations between different geometries and the resulting patterns were investigated.

  14. Investigation of the mechanical and chemical characteristics of nanotubular and nano-pitted anodic films on grade 2 titanium dental implant materials.

    Science.gov (United States)

    Weszl, Miklós; Tóth, Krisztián László; Kientzl, Imre; Nagy, Péter; Pammer, Dávid; Pelyhe, Liza; Vrana, Nihal E; Scharnweber, Dieter; Wolf-Brandstetter, Cornelia; Joób F, Árpád; Bognár, Eszter

    2017-09-01

    The objective of this study was to investigate the reproducibility, mechanical integrity, surface characteristics and corrosion behavior of nanotubular (NT) titanium oxide arrays in comparison with a novel nano-pitted (NP) anodic film. Surface treatment processes were developed to grow homogenous NT and NP anodic films on the surface of grade 2 titanium discs and dental implants. The effect of process parameters on the surface characteristics and reproducibility of the anodic films was investigated and optimized. The mechanical integrity of the NT and NP anodic films were investigated by scanning electron microscopy, surface roughness measurement, scratch resistance and screwing tests, while the chemical and physicochemical properties were investigated in corrosion tests, contact angle measurement and X-ray photoelectron spectroscopy (XPS). The growth of NT anodic films was highly affected by process parameters, especially by temperature, and they were apt to corrosion and exfoliation. In contrast, the anodic growth of NP film showed high reproducibility even on the surface of 3-dimensional screw dental implants and they did not show signs of corrosion and exfoliation. The underlying reason of the difference in the tendency for exfoliation of the NT and NP anodic films is unclear; however the XPS analysis revealed fluorine dopants in a magnitude larger concentration on NT anodic film than on NP surface, which was identified as a possible causative. Concerning other surface characteristics that are supposed to affect the biological behavior of titanium implants, surface roughness values were found to be similar, whereas considerable differences were revealed in the wettability of the NT and NP anodic films. Our findings suggest that the applicability of NT anodic films on the surface of titanium bone implants may be limited because of mechanical considerations. In contrast, it is worth to consider the applicability of nano-pitted anodic films over nanotubular arrays

  15. Studies on the production of building material grade slag from hazardous-waste incineration plants; Untersuchungen zur Herstellung einer Schlacke mit Baustoffqualitaet aus Sondermuellverbrennungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Reich, J.; Herbel, J.D.; Pasel, C. [Duisburg Univ. (Gesamthochschule) (Germany). Fachgebiet Abfalltechnik

    1998-09-01

    In an attempt to restore the competitive power of hazardous-waste incineration within the present legal framework, plant operators have in some cases lowered disposal prices below the break-even point; in this respect there is no further room for improvement. One approach towards a new marketable solution could be to use rotary kilns not only for disposal but also as production plants. This could be achieved by means of input control and loading materials. If, for example, the slag remaining after combustion could be made to meet building material specifications, thus providing a marketable product, then rotary kilns would be able to serve as production plants for a secondary raw material. If it should prove possible in the course of manufacturing campaigns to develop slags from hazardous-waste incineration plants to a marketable product, then operators will thus have complied to the demand of the Law on Recycling and Waste Management for waste avoidance and that of the Emission Control Law for residue recycling. Targeted use of suitable loading materials for quality improvement could enable operators of hazardous-waste incineration plants to secure a new strategic position on the market as building material manufacturers and utilise existing plant capacities. [Deutsch] Um die Sonderabfallverbrennung im Rahmen der rechtlichen Vorgaben wieder konkurrenzfaehig zu machen, haben die Anlagenbetreiber die Entsorgungspreise teilweise unter die Grenze der Kostendeckung zurueckgenommen; hier besteht kein Spielraum mehr. Ein neuer, marktgerechter Ansatz koennte sich dann ergeben, wenn die Drehrohroefen statt als Beseitigungsaggregate durch Inputsteuerung und Zuschlaege eventuell auch als Produktionsanlagen einzusetzen waeren. Wenn z.B. die Schlacke, als Rueckstand aus der Verbrennung, als ein im Baustoffmarkt absetzbares Produkt nach Qualitaetskriterien gezielt hergestellt wuerde, koennte der Drehrohrofen als Produktionsanlage fuer einen Sekundaerrohstoff betrieben werden

  16. Forecast and Analysis of the Main Indicators for the Development of Ocean Fishery in China during the Twelfth Five-Year Plan Period

    Institute of Scientific and Technical Information of China (English)

    Xianghong; LIN; Zhankun; WANG; Weiling; SONG; Congchun; XU

    2013-01-01

    The ocean fishery is an important part of the marine economy and an important source of human food.The leaders at all levels attach great importance to the development and utilization of ocean fishery resources.Using the regression analysis method,we forecast the main indicators for the development of ocean fishery during the Twelfth Five-Year Plan period.Through the study,it is found that in 2015,the value added of ocean fishery in China is expected to exceed 360 billion yuan,and the output of marine products will exceed 30 million tons.The marine products make stable contribution to the marine economy and the residents’nutrient composition,conducive to maintaining the stable supply of the market and meeting the residents’daily needs for marine products.

  17. Graded/Gradient Porous Biomaterials

    Directory of Open Access Journals (Sweden)

    Xigeng Miao

    2009-12-01

    Full Text Available Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young’s moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering.

  18. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt;

    2000-01-01

    was moderately reproduced (kappa = 0.59). Vascular grade was significantly associated with axillary node involvement, tumour size, malignancy grade, oestrogen receptor status and histological type. In univariate analyses vascular grade significantly predicted recurrence free survival and overall survival for all...... patients (P analysis showed that vascular grading contributed with independent prognostic value in all patients (P

  19. Asterisk Grade Study Report.

    Science.gov (United States)

    Kokorsky, Eileen A.

    A study was conducted at Passaic County Community College (PCCC) to investigate the operation of a grading system which utilized an asterisk (*) grade to indicate progress in a course until a letter grade was assigned. The study sought to determine the persistence of students receiving the "*" grade, the incidence of cases of students receiving…

  20. Processing of W-Cu functionally graded materials (FGM) through the powder metallurgy route: application as plasma facing components for ITER-like thermonuclear fusion reactor; Elaboration de materiaux W-Cu a gradient de proprietes fonctionnelles (FGM) par metallurgie des poudres: application en tant que composants face au plasma de machines de fusion thermonucleaire de type Iter

    Energy Technology Data Exchange (ETDEWEB)

    Raharijaona, J.J.

    2009-11-15

    The aim of this study was to study and optimize the sintering of W-Cu graded composition materials, for first wall of ITER-like thermonuclear reactor application. The graded composition in the material generates graded functional properties (Functionally Graded Materials - FGM). Rough thermomechanical calculations have shown the interest of W-Cu FGM to improve the lifetime of Plasma Facing Components (PFC). To process W-Cu FGM, powder metallurgy route was analyzed and optimized from W-CuO powder mixtures. The influence of oxide reduction on the sintering of powder mixtures was highlighted. An optimal heating treatment under He/H{sub 2} atmosphere was determined. The sintering mechanisms were deduced from the analysis of the effect of the Cu-content. Sintering of W-Cu materials with a graded composition and grain size has revealed two liquid migration steps: i) capillary migration, after the Cu-melting and, ii) expulsion of liquid, at the end of sintering, from the dense part to the porous part, due to the continuation of W-skeleton sintering. These two steps were confirmed by a model based on capillary pressure calculation. In addition, thermal conductivity measurements were conducted on sintered parts and showed values which gradually increase with the Cu-content. Hardness tests on a polished cross-section in the bulk are consistent with the composition profiles obtained and the differential grain size. (author)

  1. Raw Materials Selection, Formula Design and Quality Control for Producing Electronic-grade Glass Fibers%电子级玻璃纤维生产原料选用、配方设计及质量控制

    Institute of Scientific and Technical Information of China (English)

    梁红

    2013-01-01

    介绍了电子级玻璃纤维实际生产新原料的选用、配方设计、熔制氧化-还原状态量化管理。探讨各种原料质量控制。对比不同原料配方生产的拉丝成品率、满筒率、中空纤维、能耗等。阐述了各项控制指标的配合应用、精细化玻璃纤维生产管理。%An introduction is made to the raw materials selection, formula design, quantitative management of melt-ing oxidation-reduction as well as the quality control of various raw materials for actual production of electronic-grade glass fibers. . The glass strand yield, full package rate, hollow fiber percentage and energy consumption in the cases of using different formulas are conpared. Furthermore, the combination of various controls and meticulous management of glass fiber production are elaborated.

  2. Surface mechanical properties, corrosion resistance, and cytocompatibility of nitrogen plasma-implanted nickel-titanium alloys: a comparative study with commonly used medical grade materials.

    Science.gov (United States)

    Yeung, K W K; Poon, R W Y; Chu, P K; Chung, C Y; Liu, X Y; Lu, W W; Chan, D; Chan, S C W; Luk, K D K; Cheung, K M C

    2007-08-01

    Stainless steel and titanium alloys are the most common metallic orthopedic materials. Recently, nickel-titanium (NiTi) shape memory alloys have attracted much attention due to their shape memory effect and super-elasticity. However, this alloy consists of equal amounts of nickel and titanium, and nickel is a well known sensitizer to cause allergy or other deleterious effects in living tissues. Nickel ion leaching is correspondingly worse if the surface corrosion resistance deteriorates. We have therefore modified the NiTi surface by nitrogen plasma immersion ion implantation (PIII). The surface chemistry and corrosion resistance of the implanted samples were studied and compared with those of the untreated NiTi alloys, stainless steel, and Ti-6Al-4V alloy serving as controls. Immersion tests were carried out to investigate the extent of nickel leaching under simulated human body conditions and cytocompatibility tests were conducted using enhanced green fluorescent protein mice osteoblasts. The X-ray photoelectron spectroscopy results reveal that a thin titanium nitride (TiN) layer with higher hardness is formed on the surface after nitrogen PIII. The corrosion resistance of the implanted sample is also superior to that of the untreated NiTi and stainless steel and comparable to that of titanium alloy. The release of nickel ions is significantly reduced compared with the untreated NiTi. The sample with surface TiN exhibits the highest amount of cell proliferation whereas stainless steel fares the worst. Compared with coatings, the plasma-implanted structure does not delaminate as easily and nitrogen PIII is a viable way to improve the properties of NiTi orthopedic implants.

  3. A study of student attitudes toward physics and classroom environment based on gender and grade level among senior secondary education students in Indonesia

    Science.gov (United States)

    Chaerul, Andrie

    The main purposes of the present study are to investigate the differences on student's attitudes toward physics and their perceptions regarding classroom climate during physics classes based on gender and grade level. In addition, the study also explores female students' opinions about physics, and examines to what extent this factor might influence their decision to choose or not to choose physics or physics-related fields for their career choices in the future. A group of approximately 864 male and female students, equally proportioned by gender, were assigned to take part in this study. Two standardized instruments, namely the Individualized Classroom Environment Questionnaire (ICEQ) and the Test of Science Related Attitudes (TOSRA), have been employed to collect data. A combination of quantitative and qualitative methods was used to analyze the collected data resulting from the questionnaires as well as from the interviews. The study found, first, regardless of their gender and grade level differences, students expected a more positive classroom climate during learning physics. Also, it has been found that male students experience a more positive classroom environment than female students. Second, the study found that male students do show more positive attitudes toward physics than their female counterparts. Meanwhile, twelfth-grade students show a more positive attitude toward physics than eleventh-graders. Third, the study found that most female students do not like physics based on several reasons such as physics is a hard, monotonous and boring subject. Although eleventh-grade female students do not like physics, most of them intended to choose science as their major in the next grade. Surprisingly, a majority of twelfth-grade female students who are majoring in science have no intention to choose physics or physics-related subjects either for their prospective major at the university or for their career choices in the future.

  4. Asymmetric acoustic transmission in graded beam

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Li, E-mail: lj94172350@hotmail.com [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Wu, Jiu Hui, E-mail: ejhwu@mail.xjtu.edu.cn [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Guan, Dong; Lu, Kuan [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Gao, Nansha [School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072 (China); Songhua, Cao [School of Mechanical Engineering and State Key laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China)

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  5. Asymmetric acoustic transmission in graded beam

    Science.gov (United States)

    Jing, Li; Wu, Jiu Hui; Guan, Dong; Lu, Kuan; Gao, Nansha; Songhua, Cao

    2016-12-01

    We demonstrate the dynamic effective material parameters and vibration performance of a graded beam. The structure of the beam was composed of several unit cells with different fill factors. The dispersion relations and energy band structures of each unit cell were calculated using the finite element method (FEM). The dynamic effective material parameters in each unit cell of the graded beam were determined by the dispersion relations and energy band structures. Longitudinal wave propagation was investigated using a numerical method and FEM. The results show that the graded beam allows asymmetric acoustic transmission over a wide range of frequencies.

  6. Development and experiment of the grading machine for ordinary tea leaf material%大宗茶鲜叶原料分级机的研制与实验

    Institute of Scientific and Technical Information of China (English)

    任广鑫; 范起业; 何鑫; 何雪军; 李文萃; 王进; 唐小林

    2013-01-01

    机采大宗茶鲜叶长短不一、老嫩不同,以此为原料制得的茶叶品质较低,为此研制了一种新型的抛掷式大宗茶鲜叶分级机,该机由分级槽体、传动机构、摇杆和机架等部分组成,通过抛掷的方式对茶鲜叶进行分级.结果表明,使用第二批次茶鲜叶进行分级,投叶量为5kg/min、振动频率为50Hz时,分级机的平均分净率最高,达79.04%,挂网率为3.60%.可见,该机能较好地实现机采大宗茶鲜叶的分级.%Machine-plucked tea possessed different lengths and with varied tenderness,such material would surely result in poor tea quality.To solve this problem,a new grading machine which worked according to the casting principle was developed.lt was composed of a classification trough, a power transmission line, a rocker and a frame.The results showed that when the second batch of fresh leaf material was treated, and with a feed rate 5kg/min and vibration frequency 50Hz,the average classification rate was as high as 79.04% ,and materials caught in the net was 3.60%.Above all,it was a machine which can effectively realize the classification of the machine-plucked tea leaves.

  7. 高中信息技术教材评价体系构建与等级测定%High School Information Technology Teaching Materials Evaluation System Strucuture and Grade Estimation

    Institute of Scientific and Technical Information of China (English)

    刘力; 张晓卉

    2011-01-01

    教材评价是教材研究的重要内容,是教育评价的重要组成部分,高中信息技术教材的评价和选用对于信息技术课程质量、教学效果和学生学习有着十分重要的作用.结合高中信息技术课程的特点,借鉴其他学科的研究成果,以作为参考基准,从知识与技能、思想与文化内涵、认知与心理规律、编制水平、可行性与效果等5个维度进行归纳提炼,构建高中信息技术教材评价体系,并以高中信息技术教师为评价主体,对当前使用的新课程标准下高中信息技术实验教材进行等级测定与评价过程分析.结果显示,高中信息技术教材评价体系的有效性、准确性比较理想,评价方法切实可行.教师对教材的较高的认可程度有利于实验教材的推广和高中信息技术课程有效实施.%Teaching materials evaluation is an important content of the teaching materials research and education evaluation.Evaluating and selecting high school information technology teaching materials play a very important role in information technology curriculum quality, teaching effect and students' learning.Combined with the characteristics of high school information technology course, draw lessons from other disciplines of research results, with the high school curriculum standard of information technology as the reference datum.Summarized and refined from knowledge and skills, and taking five aspects as thought and culture connotation, cognitive and psychological law, staffing levels, feasibility and effect, we construct evaluation system of high school information technology teaching materials.Based on the constructing evaluation system of high school information technology teaching materials, high school teachers, as subject, evaluate the grade of high school information technology experimental teaching materials accounting to new curriculum standard.This paper analyses the evaluation process,concludes that evaluation system

  8. Almost Graded Prime Ideals

    Directory of Open Access Journals (Sweden)

    Ameer Jaber

    2008-01-01

    Full Text Available Problem Statement: Graded commutative ring with unity over an abelian group were introduced by many authors such as T. Y. Lam and C. T. C. Wall, and almost prime ideals over commutative rings with unity were introduced by S.M. Batwadeker and P.K. Sharma, and this forced us to try to extend the theory of almost and n-almost prime ideals to the graded case. Approach: We develop the theory of almost and n-almost prime ideals to the graded case. Results: We extended some basic results about almost and n-almost prime ideals to the graded case, and then we gave a relationship between n-almost graded prime ideals and weakly graded prime ideals. Conclusion: The extended results about almost and n-almost graded prime ideals allow us to classify further properties about almost graded prime ideals. 2000 AMS Mathematics Subject Classification: 13 A 02.

  9. CT Grading of Otosclerosis

    National Research Council Canada - National Science Library

    Lee, T.C; Aviv, R.I; Chen, J.M; Nedzelski, J.M; Fox, A.J; Symons, S.P

    2009-01-01

    ...: The CT grading system for otosclerosis was proposed by Symons and Fanning in 2005. The purpose of this study was to determine if this CT grading system has high interobserver and intraobserver agreement...

  10. Gleason grading system

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000920.htm Gleason grading system To use the sharing features on this page, ... score of between 5 and 7. Gleason Grading System Sometimes, it can be hard to predict how ...

  11. The Effect Of Ceramic In Combination Of Two Sigmoid Functionally Graded Rotating Disks With Variable Thickness

    DEFF Research Database (Denmark)

    Bayat, M.; Sahari, B. B.; Saleem, M.

    2012-01-01

    In this paper the elastic solutions of a disk composed of FGM – Functionaly Graded Material, is presented.......In this paper the elastic solutions of a disk composed of FGM – Functionaly Graded Material, is presented....

  12. Colorado Student Assessment Program: 2001 Released Passages, Items, and Prompts. Grade 4 Reading and Writing, Grade 4 Lectura y Escritura, Grade 5 Mathematics and Reading, Grade 6 Reading, Grade 7 Reading and Writing, Grade 8 Mathematics, Reading and Science, Grade 9 Reading, and Grade 10 Mathematics and Reading and Writing.

    Science.gov (United States)

    Colorado State Dept. of Education, Denver.

    This document contains released reading comprehension passages, test items, and writing prompts from the Colorado Student Assessment Program for 2001. The sample questions and prompts are included without answers or examples of student responses. Test materials are included for: (1) Grade 4 Reading and Writing; (2) Grade 4 Lectura y Escritura…

  13. GRADE Equity Guidelines 3

    DEFF Research Database (Denmark)

    Welch, Vivian A; Akl, Elie A; Pottie, Kevin

    2017-01-01

    OBJECTIVE: The aim of this paper is to describe a conceptual framework for how to consider health equity in the GRADE (Grading Recommendations Assessment and Development Evidence) guideline development process. STUDY DESIGN AND SETTING: Consensus-based guidance developed by the GRADE working grou...

  14. [Grading of prostate cancer].

    Science.gov (United States)

    Kristiansen, G; Roth, W; Helpap, B

    2016-07-01

    The current grading of prostate cancer is based on the classification system of the International Society of Urological Pathology (ISUP) following a consensus conference in Chicago in 2014. The foundations are based on the frequently modified grading system of Gleason. This article presents a brief description of the development to the current ISUP grading system.

  15. Numerical Evaluations of Functionally Graded RC Slabs

    Directory of Open Access Journals (Sweden)

    M. Mastali

    2014-01-01

    Full Text Available Nowadays, using fibrous materials is used widely in strengthening applications such as cross-section enlargement and using functionally graded reinforced concrete. Functionally graded reinforced concrete is used as multireinforced concrete layers that can be reinforced by different fiber types. The objective of this research was to address the structural benefits of functionally graded concrete materials by performing analytical simulations. In order to achieve this purpose, in the first stage of this study, three functionally graded reinforced concretes by steel and polypropylene (PP were experimentally tested under flexural loading. Inverse analysis was applied to obtain the used material properties of reinforced concrete by FEMIX software. After obtaining the material properties, to assess the performance of proposed slabs, some other cases were proposed and numerically evaluated under flexural and shear loading. The results showed that increasing steel fiber in reinforced entire cross section led to achieve better shear and flexural performance while the best performance of reinforced functionally graded slabs was achieved for slab at 1% fiber content. In the second stage, nineteen reinforced functionally graded RC slabs with steel bars were simulated and assessed and some other cases were considered which were not experimentally tested.

  16. Engaging in Argument from Evidence and the Ocean Sciences Sequence for Grades 3-5: A case study in complementing professional learning experiences with instructional materials aligned to instructional goals

    Science.gov (United States)

    Schoedinger, S. E.; Weiss, E. L.

    2016-12-01

    K-5 science teachers, who often lack a science background, have been tasked with a huge challenge in implementing NGSS—to completely change their instructional approach from one that views science as a body of knowledge to be imparted to one that is epistemic in nature. We have found that providing high-quality professional learning (PL) experiences is often not enough and that teachers must have instructional materials that align with their instructional goals. We describe a case study in which the Lawrence Hall of Science (the Hall) used the Hall-developed Ocean Sciences Sequence for Grades 3-5 (OSS 3-5) to support a rigorous PL program for grade 3-5 teachers focused on the NGSS science and engineering practice, engaging in argument from evidence. Developed prior to the release of NGSS, the Ocean Literacy Framework and the NGSS precursor, A Framework for K-12 Science Education, informed the content and instructional approaches of OSS 3-5. OSS 3-5 provides a substantial focus on making evidence-based explanations (and other science practices), while building students' ocean sciences content knowledge. From 2013-2015, the Hall engaged cohorts of teachers in a rigorous PL experience focused on engaging in argument from evidence. During the summer, teachers attended a week-long institute, in which exemplar activities from OSS 3-5 were used to model instructional practices to support arguing from evidence and related practices, e.g., developing and using models and constructing explanations. Immediately afterward, teachers enacted what they'd learned during a two-week summer school practicum. Here, they team-taught the OSS 3-5 curriculum, participated in video reflection groups, and received coaching and just-in-time input from instructors. In the subsequent academic year, many teachers began by teaching OSS 3-5 so that they could practice engaging students in argumentation in curriculum they'd already used for that purpose. Throughout the year, teachers

  17. The Weight of Evidence Does Not Support the Listing of Styrene as “Reasonably Anticipated to be a Human Carcinogen” in NTP's Twelfth Report on Carcinogens

    Science.gov (United States)

    Rhomberg, Lorenz R.; Goodman, Julie E.; Prueitt, Robyn L.

    2013-01-01

    Styrene was listed as “reasonably anticipated to be a human carcinogen” in the twelfth edition of the National Toxicology Program's Report on Carcinogens based on what we contend are erroneous findings of limited evidence of carcinogenicity in humans, sufficient evidence of carcinogenicity in experimental animals, and supporting mechanistic data. The epidemiology studies show no consistent increased incidence of, or mortality from, any type of cancer. In animal studies, increased incidence rates of mostly benign tumors have been observed only in certain strains of one species (mice) and at one tissue site (lung). The lack of concordance of tumor incidence and tumor type among animals (even within the same species) and humans indicates that there has been no particular cancer consistently observed among all available studies. The only plausible mechanism for styrene-induced carcinogenesis—a non-genotoxic mode of action that is specific to the mouse lung—is not relevant to humans. As a whole, the evidence does not support the characterization of styrene as “reasonably anticipated to be a human carcinogen,” and styrene should not be listed in the Report on Carcinogens. PMID:23335843

  18. Are grades really oppressive?

    Institute of Scientific and Technical Information of China (English)

    张心宇

    2015-01-01

    Are grades really oppressive? The broad question's answer is of course open: it varies in different condition and in prerequisites. Like in Daily Californian,"Why Grades are Oppressive", the title tells us it standing: yes, grades are oppressive. In the article, the authors (this article was written by 16 students of the class) pointed out that the grading system has had a violent and powerfully destructive effect on our lives. Because grading focuses our attention on class requirements that we have no say in determination. And this makes many students equate their self-worth with the grades they get in exams. Besides, grades are intimately connected with a larger system of control in community, which trains students to be submissive and not to question or challenge it. In the end, the authors conclude that they should take responsibility for evaluating their own learning process.

  19. Clinical grades: upward bound.

    Science.gov (United States)

    Walsh, Catherine M; Seldomridge, Lisa A

    2005-04-01

    This study examined the relationship of grades earned in paired theory and clinical courses. Data collected during academic years 1997 to 2002 confirmed that grade inflation exists in clinical nursing courses. Problems involved in awarding grades for clinical performance are discussed (e.g., standards of clinical performance, methods used in evaluation of clinical performance, the impossibility of faculty omnipresence, the influence of student effort in grading, the effect of recency, the challenges of keeping good anecdotal records). Solutions to grading problems are proposed, including dividing up performance into agreed-on elements, measurement of these elements on a grading scale that allows for more differentiation of quality in evaluating clinical performance, assigning grades from the beginning of a clinical course, emphasizing all three domains of clinical practice, and evaluating student performance in both laboratory and, clinical settings.

  20. Robinson′s cytological grading on aspirates of breast carcinoma: Correlation with Bloom Richardson′s histological grading

    Directory of Open Access Journals (Sweden)

    Sinha S

    2009-01-01

    Full Text Available Background : Cytological grading (CG on aspirates of breast carcinoma is a useful tool for surgical maneuver and prognosis. Aims : An endeavor was made to use CG on aspirates of breast carcinoma using Robinson′s grade and to correlate it with Bloom Richardsons′ histopathological grading. Materials and Methods : A total of 59 patients of breast carcinoma, aged 28-57 years, were aspirated and the smears were graded using Robinson′s criteria. All the cases were correlated with Bloom Richardson′s grade on histopathology in mastectomy specimens. Lymphadenopathy in 38 cases was aspirated and stained with Papanicolaou and Romanowsky stain. Results : Robinson′s CG correlated well with Bloom Richardson′s histopathological grading. For grade I and II tumors, there was substantial strength of agreement between cytology and histopathology, while in grade III, the concordance was nearly perfect. Lymph node metastasis was found in 27 of 32 axillary nodes, three of five cervical nodes and the only palpable supraclavicular node. Lymph node metastasis was observed in three with cytological grade II, 28 of grade III and none of grade I. All grade I had stage A, two of grade II had stage B, while all grade III had either stage B or stage C disease. Conclusions : Thus, CG of breast carcinoma correlates well with histopathological grading and may well be useful as a prognostic marker.

  1. Drama Curriculum--V and VI [Grades Five and Six], Teacher's Guides; Supplementary Materials: The Magic Drum, The Squire's Bride, The Fool of the World and The Flying Ship; The Cat Who Walked by Himself, The Story of Keesh.

    Science.gov (United States)

    Oregon Univ., Eugene. Oregon Elementary English Project.

    These curriculum guides are designed to introduce drama to students at the fifth and sixth grade level. The teacher's guide for each of the two grade levels presents 41 lessons. Each lesson includes a description of objectives and various exercises, including movement warm-ups, concentration warm-ups, descriptions of the character type to be…

  2. THE MORE CAPABLE LEARNER, GRADE 3.

    Science.gov (United States)

    KELLENBERGER, DARIUS; AND OTHERS

    THE COLLECTION OF MATERIALS PROVIDES ENRICHMENT ACTIVITIES FOR THIRD GRADE PUPILS. AN INTRODUCTORY SECTION OFFERS AIDS TO THE TEACHER IN IDENTIFYING THE MORE ABLE STUDENT AND IN TEACHING SOCIAL STUDIES, ART APPRECIATION, ARITHMETIC, AND HAIKU - A POETRY FORM. THE SECOND SECTION IS A COMPILATION OF SAMPLE COPIES OF PUPIL MATERIALS. THE MATERIALS…

  3. THE MORE CAPABLE LEARNER, GRADE 4.

    Science.gov (United States)

    SELDERS, HAL; AND OTHERS

    THE COLLECTION OF MATERIALS PROVIDES ENRICHMENT ACTIVITIES FOR THE FOURTH GRADE STUDENT. THE TEACHER'S SECTION INCLUDES--SUGGESTIONS FOR USING THE PUPIL MATERIALS, CHARACTERISTICS OF THE MORE ABLE LEARNER, A CHECK LIST FOR IDENTIFYING THE MORE ABLE LEARNER, AND AN ACTIVITIES CHART SHOWING THE OVERLAPPING USE OF VARIOUS ACTIVITIES TO AID IN THE…

  4. Functionally Graded Adhesives for Composite Joints

    Science.gov (United States)

    Stapleton, Scott E.; Waas, Anthony M.; Arnold, Steven M.

    2012-01-01

    Adhesives with functionally graded material properties are being considered for use in adhesively bonded joints to reduce the peel stress concentrations located near adherend discontinuities. Several practical concerns impede the actual use of such adhesives. These include increased manufacturing complications, alterations to the grading due to adhesive flow during manufacturing, and whether changing the loading conditions significantly impact the effectiveness of the grading. An analytical study is conducted to address these three concerns. An enhanced joint finite element, which uses an analytical formulation to obtain exact shape functions, is used to model the joint. Furthermore, proof of concept testing is conducted to show the potential advantages of functionally graded adhesives. In this study, grading is achieved by strategically placing glass beads within the adhesive layer at different densities along the joint.

  5. Contract grading in clinical evaluation.

    Science.gov (United States)

    Schoolcraft, V; Delaney, C

    1982-01-01

    The use of contracts in grading clinical performance has provided faculty with a solution to two important problems. One has been how to ensure that students are graded consistently among the various faculty who are grading the same clinical component of a course. The second has been to increase the opportunity for individualized attention to student learning needs. We have been pleased to see all the faculty members increase their input and involvement in the continuing modifications of the contract. Although we have taken the major responsibility for the semi-annual revisions of the contract, other faculty members have been increasingly more explicit in their evaluations and suggestions as their experience with the contract has expanded. Their confidence in this method of clinical evaluation has increased with each semester of use. We plan to continue in the refinement of the instrument and will develop materials for the use of other faculty groups who are interested in developing similar contracts. We are also designing a survey to attempt to discover how widespread is the use of contract grading in clinical areas.

  6. A Simple Alternative to Grading

    Science.gov (United States)

    Potts, Glenda

    2010-01-01

    In this article, the author investigates whether an alternative grading system (contract grading) would yield the same final grades as traditional grading (letter grading), and whether or not it would be accepted by students. The author states that this study demonstrated that contract grading was widely, and for the most part, enthusiastically…

  7. 基于功能梯度材料的充液圆柱壳耦合振动研究%Coupled Vibration of Fluid-filled Functionally Graded Material Cylindrical Shell

    Institute of Scientific and Technical Information of China (English)

    梁斌; 李戎; 张伟

    2011-01-01

    根据Love壳体理论研究了基于功能梯度材料的充液圆柱壳的耦合振动特性.利用波动法,推导出考虑液体影响时FG圆柱壳耦合系统的振动方程.通过变换轴向波数,得到不同边界条件下充液FG圆柱壳的固有频率.与已有文献的分析结果进行对比,验证了文中研究的准确性.研究表明,液体对FG圆柱壳的固有频率有着明显的影响,轴向半波数、边界条件和壳体长度与半径比对固有频率的影响主要表现在周向波数较小的情况下.%The coupled vibration of fluid-filled cylindrical shell based on functionally graded material (FG) is presented.The study is carried out using Love's thin shell theory.Based on wave propagation method the equation of motion of the coupled system with the fluid effect is derived.By means of conversion switch on axial wave number,the coupled frequency of FG cylindrical shell with various boundary conditions is obtained.Then the frequency of fluid-filled FG cylindrical shell with different boundary conditions is illustrated by examples.The present analysis is validated by comparing results with those in the literature.The results show that the influences of liquids on natural frequencies of fluid-filled FG cylindrical shell are obvious.The effects of axial half wave number,boundary condition and ratio of length to radius on natural frequencies have mainly manifested in the cases of low circumferential wave numbers.

  8. Plasma Nitriding of CP Titanium Grade-2 and Ti-6Al-4V Grade-5

    Science.gov (United States)

    Deepak, J. R.; Bupesh Raja, V. K.; Senthil Kumar, J.; Thomas, Subin; Raju Vithaiyathil, Thomas

    2017-05-01

    Titanium metal is considered to be asset material due to its high tribological properties. Since these tribological properties like hardness, roughness, wear resistance etc. are influenced by the surface properties of the material, so obviously any changes in the surface of the material has direct impact on the tribological properties too. Nitriding is a heat-treating process that diffuses nitrogen into the surface of a metal to create a case hardened surface. The main objective is that to implement the plasma nitriding process to both CP Titanium grade-2 and Ti-6Al-4V grade-5 and to observe the improvements in the tribological properties with respect to the parent materials.

  9. Correlation between cytological and histological grading of breast cancer and its role in prognosis

    Science.gov (United States)

    Pal, Shweta; Gupta, Mohan Lal

    2016-01-01

    Context: Assigning grade to breast cancer on FNAC provides prognostic information and guides optimal therapy. Aims: The present study was undertaken to grade breast carcinoma on cytology by Robinson's grading system and correlate it with Elstons modified Bloom Richardson histological grading system. Settings and Design: It is a prospective study done on fifty cases of breast cancer reported on cytology. Materials and Methods: Fifty patients who underwent FNAC and mastectomy for breast carcinoma were cytologically and histologically graded. Correlation between cytological and histological grading system was determined. Sensitivity and specificity of Robinson's cytological grading system was calculated in each grade. All cases evaluated for presence of metastasis to axillary lymph nodes. Statistical Analysis Used: Correlation between cytological and histological grading was established using the non parametric Spearman’ s correlation coefficient. Results: Concordance rate between cytological and histological grade was 78%. The coefficient of correlation between cytological grade and histological grade was 0.804 and P value was <0.001 which indicated a strong correlation and significant association between the cytological and histological grade. Sensitivity was maximum in cytological grade I tumors (100%) and least in cytological grade III tumors (45.45%). Specificity was maximum in cytological grade III tumors (94.87%) and least in cytological grade II tumors (72.72%). The incidence of axillary lymph node metastasis was maximum in cytological grade III tumors and grade I tumors. Conclusions: Cytological grade strongly predicts histological grade and is useful in selecting neoadjuvant chemotherapy. PMID:28028331

  10. The Twelfth Five-Year Plan of China's dyeing and finishing industry%印染行业“十二五”发展规划

    Institute of Scientific and Technical Information of China (English)

    中国印染行业协会

    2012-01-01

    During the " Eleventh Five-Year" period, the production and marketing of China's dyeing and finishing industry kept sustained growth, structural adjustment gained substantial achievements, energy saving and emission reduction firmly pushed forward. The development model appeared to transform from quantity-oriented growth pattern to quality-oriented one. During the " Twelfth Five-Year" period, the dyeing and finishing industry should put more emphasis on technology advance, product research and development, resource saving and environment protection The industry need to promote the products' quality and added values, increase the production efficiency, reduce the production cost and the pollutant release, improve profitability and the quality and efficiency of economic growth, and speed up the transformation from quantity-oriented growth pattern to quality-oriented one%“十一五”期间,我国印染行业生产销售持续增长,经济效益稳步提高,产业结构调整取得成效,节能减排扎实推进;产业发展从数量型增长向质量效益型增长转变明显.“十二五”期间,印染行业应更加注重科技进步,注重产品研发和市场营销,注重资源节约和环境保护,提升产品质量和附加值,提高生产效率,降低生产成本,减少污染物排放,提升企业的赢利能力和水平,提高经济增长的质量和效益,推动行业由资源数量型增长向质量效益型增长转变.

  11. Materials for Fusion Applications

    Directory of Open Access Journals (Sweden)

    Jiří Matějíček

    2013-01-01

    Full Text Available An overview of materials foreseen for use or already used in fusion devices is given. The operating conditions, material requirements and characteristics of candidate materials in several specific application segments are briefly reviewed. These include: construction materials, electrical insulation, permeation barriers and plasma facing components. Special attention will be paid to the latter and to the issues of plasma-material interaction, materials joining and fuctionally graded interlayers.

  12. Classroom: Efficient Grading

    Science.gov (United States)

    Shaw, David D.; Pease, Leonard F., III.

    2014-01-01

    Grading can be accelerated to make time for more effective instruction. This article presents specific time management strategies selected to decrease administrative time required of faculty and teaching assistants, including a multiple answer multiple choice interface for exams, a three-tier grading system for open ended problem solving, and a…

  13. Pallet part grading trainer

    Science.gov (United States)

    Deborah F. Cook; Philip A. Araman; Matthew F. Winn

    2000-01-01

    A computerized pallet grading training system was developed to facilitate the production of higher quality pallets. Higher quality pallets would be more durable and could be re-used many times, resulting in long-term savings. Schmoldt et al. (1993) evaluated the economic impact of grading and sorting pallet parts. They determined that higher quality pallets produced by...

  14. Beef grading by ultrasound

    Science.gov (United States)

    Gammell, P. M.

    1981-01-01

    Reflections in ultrasonic A-scan signatures of beef carcasses indicate USDA grade. Since reflections from within muscle are determined primarily by fat/muscle interface, richness of signals is direct indication of degree of marbling and quality. Method replaces subjective sight and feel tests by individual graders and is applicable to grade analysis of live cattle.

  15. Grading Exceptional Learners

    Science.gov (United States)

    Jung, Lee Ann; Guskey, Thomas R.

    2010-01-01

    Teachers often grapple with the challenge of giving report card grades to students with learning disabilities and English language learners. The authors offer a five-step model that "offers a fair, accurate, and legal way to adapt the grading process for exceptional learners." The model begins with a high-quality reporting system for all students…

  16. Minimum Grading, Maximum Learning

    Science.gov (United States)

    Carey, Theodore; Carifio, James

    2011-01-01

    Fair and effective schools should assign grades that align with clear and consistent evidence of student performance (Wormeli, 2006), but when a student's performance is inconsistent, traditional grading practices can prove inadequate. Understanding this, increasing numbers of schools have been experimenting with the practice of assigning minimum…

  17. 内蒙古自治区“十二五”期间煤电发展空间测算%Calculation of coal power development during the “Twelfth Five Planning” in Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    卢艳丽; 宋志博

    2015-01-01

    根据内蒙古自治区2010年的 SO2和 NOx 排放现状,结合现行减排政策和排放标准要求,分析“十二五”期间内蒙古现役源的 SO2和 NOx 减排潜力。根据“十二五”SO2和 NOx 总量控制目标,分析新源可用的排放指标空间。测算“十二五”期间非电力行业的污染物排放增量,在此基础上分析电力行业排放指标空间可供发展的新建燃煤机组规模。%According to the SO2 and NOx emission status of the Inner Mongolia in 2010,according to the current emission reduction policies and emission standards, SO2 and NOx emission reduction potential of Inner Mongolia active source analysis of the " Twelfth Five Planning " period. According to the SO2 and NOx total control objectives of the "Twelfth Five Planning ", analysis of space available source emission index. Calculation of the " Twelfth Five Planning " period in nonpower industry increment of pollutant emissions, the scale of the new coal-fired units on the basis of analysis of emission index of electric power industry for the development of space.

  18. 亚表面异质缺陷对功能梯度材料表面温度场的影响%Influence of inclusion in functionally graded materials on the surface temp erature distributions

    Institute of Scientific and Technical Information of China (English)

    马晓波; 王飞; 陈德珍

    2014-01-01

    基于双曲型热传导方程,采用镜像法和波函数展开法,求解了含亚表面异质圆柱缺陷的半无限功能梯度材料的表面温度场,给出了功能梯度材料中热波散射的一般解。分析了亚表面异质圆柱缺陷的几何参数(如埋藏深度)和热物理参数(如导热系数、热扩散长度、热扩散率及热弛豫时间等)对功能梯度材料表面温度场的影响。温度波由调制的超短脉冲激光在功能梯度材料表面激发,异质圆柱缺陷表面的边界条件为导热边界。研究结果可望为功能梯度材料的红外热波无损检测、导热反问题提供计算方法和参考数据。%In this paper, based on the hyperbolic equation of heat conduction, utilizing the image method and the wave function expansion method, the temperature distributions on the surface of a functionally graded material(FGM) containing a cylindrical inclusion are investigated. According to the model of thermal waves, a general solution of scattered fields of thermal waves is obtained. Effects of different physical parameters (such as the depth of buried inclusion, the thermal conductivity, the thermal diffusion length, the thermal diffusivity, and the thermal relaxation time) on the distribution of temperature are analyzed. The thermal waves are excited on the surface of the FGM by a periodically modulated laser. A cylindrical defect is taken as an inclusion under a thermal conduction condition. Results are expected to provide calculation methods and reference data for infrared thermal wave nondestructive evaluation of an FGM and the inverse problems in mathematical physics.

  19. Characterizations of Graded Distributive Modules

    Institute of Scientific and Technical Information of China (English)

    Qinghua Chen; Chang'an Li

    2002-01-01

    In this paper, we give some characterizations of graded distributive modules, prove some interesting results between graded rings (modules) and lattices under finiteness conditions, and investigate the direct sum of graded distributive modules in terms of orders of graded submodules and homomorphisms of graded factor modules.

  20. Paperless Grades and Faculty Development.

    Science.gov (United States)

    Hardy, James C.; Jones, Dennis; Turner, Sandy

    2003-01-01

    Provides overview of process of switching from paper-based grade reporting to computer-based grading. Authors found that paperless grading decreased number of errors, made student access more immediate, and reduced costs incurred by purchasing and storing grade-scanning sheets. Authors also argue that direct entry grading encourages faculty to…

  1. Grading for Understanding - Standards-Based Grading

    Science.gov (United States)

    Zimmerman, Todd

    2017-01-01

    Standards-based grading (SBG), sometimes called learning objectives-based assessment (LOBA), is an assessment model that relies on students demonstrating mastery of learning objectives (sometimes referred to as standards). The goal of this grading system is to focus students on mastering learning objectives rather than on accumulating points. I have used SBG in an introductory physics course for the past five years and worked with several physics faculty members to implement SBG in the first and second semester of algebra-based and calculus-based introductory physics courses at a primarily undergraduate comprehensive public university with class sizes of 48 students. In this article I will discuss methods for implementing SBG in a physics class.

  2. Nebraska Science Standards: Grades K-12

    Science.gov (United States)

    Nebraska Department of Education, 2010

    2010-01-01

    This publication presents the Nebraska Science Standards for Grades K-12. The standards are presented according to the following grades: (1) Grades K-2; (2) Grades 3-5; (3) Grades 6-8; and (4) Grades 9-12.

  3. Composition and bandgap-graded semiconductor alloy nanowires.

    Science.gov (United States)

    Zhuang, Xiujuan; Ning, C Z; Pan, Anlian

    2012-01-03

    Semiconductor alloy nanowires with spatially graded compositions (and bandgaps) provide a new material platform for many new multifunctional optoelectronic devices, such as broadly tunable lasers, multispectral photodetectors, broad-band light emitting diodes (LEDs) and high-efficiency solar cells. In this review, we will summarize the recent progress on composition graded semiconductor alloy nanowires with bandgaps graded in a wide range. Depending on different growth methods and material systems, two typical nanowire composition grading approaches will be presented in detail, including composition graded alloy nanowires along a single substrate and those along single nanowires. Furthermore, selected examples of applications of these composition graded semiconductor nanowires will be presented and discussed, including tunable nanolasers, multi-terminal on-nanowire photodetectors, full-spectrum solar cells, and white-light LEDs. Finally, we will make some concluding remarks with future perspectives including opportunities and challenges in this research area.

  4. Comparative evaluation of various cytomorphological grading systems in breast carcinoma

    Directory of Open Access Journals (Sweden)

    P Arul

    2016-01-01

    Full Text Available Background: The diagnosis of breast carcinoma can be reliably made by fine needle aspiration cytology (FNAC. Grading usually done in histological samples for the selection of therapy but not in cytology. Various cytological grading systems have been proposed; however, none of them is presently considered the gold standard to predict the prognosis. Aim: This study was undertaken to evaluate various 3-tier cytological grading systems and to determine the best possible system corresponds to the histological grading proposed by Elston and Ellis based on the method by Nottingham modification of Scarff-Bloom-Richardson (SBR method. Materials and Methods: In this retrospective study, 94 cases of breast carcinoma FNACs were graded using six cytological grading systems and compared with SBR method. Concordance, association, and correlation studies were done to select best possible cytological grading system. The interobserver reproducibility among the six grading systems was also assessed. Results: Robinson method showed best correlation (r = 0.801; P = 0.0001 and t = 0.783; P = 0.0001, maximum percent agreement (83/94 cases; 88.3%, and a substantial kappa value of agreement (k = 0.737 with the Nottingham modification of SBR grading system followed by Mouriguand method. Taniguchi system showed better interobserver agreement (87.2%; k= 0.738. Conclusions: This study showed that all six cytological grading systems correlated positively with SBR method. However, Robinson's grading system demonstrated the best concordance, correlation, and substantial Kappa value of the agreement with the histological grading by SBR method in comparison to other 3-tier cytological grading systems. Hence, in conclusion, this grading should be routinely incorporated in the cytology reports as it correlates well with histological grade. Despite various cytological grading systems, Robinson's method is simple, more objective, and reproducible, hence being preferable for routine

  5. Cytological grading: An alternative to histological grading in oral squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Srilekha Namala

    2016-01-01

    Full Text Available Background: Micronuclei (MN in oral exfoliative cells have been shown to indicate a disparaging change in genetic information of the cell. Recent studies showed correlation between the frequency of MN and severity of this damage. Grading of lesions can be used to determine the austerity of this damage. Aims: The aim of this study is to compare the MN frequency in oral exfoliated cells of normal and oral squamous cell carcinoma (OSCC individuals and to cytologically grade the frequency of MN in cytological smears and to correlate it with histological grading. The objective is to ascertain whether MN frequency in oral exfoliated cells can be a parameter for grading of OSCC. Settings and Design: The study group comprises of 40 subjects (20 controls and 20 OSCC patients in the age group of 45-85 years. Materials and Methods: The cytosmear was obtained from each group and stained with Papanicolaou (PAP stain. Twenty cells from each slide were counted for MN and cytological grade of OSCC was assigned based on the average frequency of MN. Cytological grade was correlated with histological grading and the data were recorded. Student′s t-test and Spearman′s correlation were used for the analysis of the data. Results: Average frequency of MN was 2.5 times higher in OSCC patients when compared to that in controls and the difference was found to be highly significant. Sixty percent correlation was found between cytological grade and histological grade of OSCC and the difference between them was not significant. Conclusions: Cytological grading can be used in grading OSCC, and MN insinuates genotoxic damage occurring in the epithelial cells.

  6. The Grade Contract Revisited

    Science.gov (United States)

    Bornscheuer, Joan H.

    1976-01-01

    Adaptations of and variations on the grade contract system are described with emphasis on individualized instruction, fair evaluation, and learner-oriented classes. The method used is described, and results are assessed. (Author/RM)

  7. Clinical performance of a human papillomavirus messenger RNA test (Aptima HPV Assay) on residual material from archived 3-year-old PreservCyt samples with low-grade squamous intraepithelial lesion

    DEFF Research Database (Denmark)

    Waldstrøm, Marianne; Ornskov, Dorthe

    2011-01-01

    Human papillomavirus (HPV) testing is widely used in the triage of women with a borderline smear result but the efficiency of testing women with low-grade squamous intraepithelial lesion (LSIL) is less clear, mainly because of lack of specificity. New HPV tests are emerging, which detect E6/E7...

  8. 荆州市基础测绘“十二五”规划编制研究%The Twelfth Five-Year Planning Research of the Basic Surveying and Mapping in Jingzhou

    Institute of Scientific and Technical Information of China (English)

    周勇; 胡冰; 彭李; 石莎

    2012-01-01

    基础测绘是国民经济和社会发展的一项长期的基础性工作。分析了荆州市基础测绘“十一五”期间取得的成绩和存在的问题,阐述了“十二五”期间经济社会发展对基础测绘的需求,提出了基础测绘的发展目标,明确了基础测绘的6项任务,制定了基础测绘重点项目规划,为地市级基础测绘“十二五”规划编制提供思路。%Basic surveying and mapping is a long-term basic and strategic work of the economic and social develop- ment. The paper analyzes the achievements and existing problems of Jingzhou basic surveying and mapping during the E- leventh Five-Year Plan period, describes the needs of economic and social development during the Twelfth Five-year Plan period. It proposes development goals of basic surveying and mapping, defines its six tasks and formulates key pro- jects plan. Ideas for establishing city basic surveying and mapping during the Twelfth Five-Year Plan are presented.

  9. Research on Affordable Housing Construction of Shanxi Province during the Twelfth Five-year Plan%山西省城镇"十二五"经济适用房研究

    Institute of Scientific and Technical Information of China (English)

    范恩海; 郑婷兰

    2011-01-01

    经济适用房是我国住房保障体系的重要组成部分,"十二五"期间应该加大经济适用房建设力度,以满足城镇中(低)收入家庭的基本住房需求.借助以及市场调查等统计资料,通过分析山西省商品住房市场价格、城镇新增居民家庭人均可支配收入等情况,预测得到经济适用房的保障线标准和保障比例,从而确定出"十二五"期间新增经济适用房的建设数量.%Affordable housing is an important part of China's housing security system. We should intensify affordable housing construction during the twelfth five-year to meet the basic housing demand of low-and middle-income families. With the help of statistical date which quoted from The Clorious 60 Years of Shanxi and market research statistical data through the analysis of the commodity housing market prices and per capita disposable income of urban increased households in Shanxi Province, predicts the security standards and security proportion of affordable housing, so as to determine the increased construction quantity of affordable housing during the twelfth five-year.

  10. Crack propagation in fracture mechanical graded structures

    Directory of Open Access Journals (Sweden)

    B. Schramm

    2015-10-01

    Full Text Available The focus of manufacturing is more and more on innovative and application-oriented products considering lightweight construction. Hence, especially functional graded materials come to the fore. Due to the application-matched functional material gradation different local demands such as absorbability, abrasion and fatigue of structures are met. However, the material gradation can also have a remarkable influence on the crack propagation behavior. Therefore, this paper examines how the crack propagation behavior changes when a crack grows through regions which are characterized by different fracture mechanical material properties (e.g. different threshold values KI,th, different fracture toughness KIC. In particular, the emphasis of this paper is on the beginning of stable crack propagation, the crack velocity, the crack propagation direction as well as on the occurrence of unstable crack growth under static as well as cyclic loading. In this context, the developed TSSR-concept is presented which allows the prediction of crack propagation in fracture mechanical graded structures considering the loading situation (Mode I, Mode II and plane Mixed Mode and the material gradation. In addition, results of experimental investigations for a mode I loading situation and numerical simulations of crack growth in such graded structures confirm the theoretical findings and clarify the influence of the material gradation on the crack propagation behavior.

  11. Mechanical properties of CNT reinforced hybrid functionally graded materials for bioimplants%生物植入用碳纳米管增强混合功能梯度材料的力学性能

    Institute of Scientific and Technical Information of China (English)

    M Asif HUSSAIN; Myong Ho KIM; Adnan MAQBOOL; F Ahmad KHALID; Nabi BAKHSH; Ali HUSSAIN; Jamil Ur RAHMAN; Jong Kyu PARK; Tae Gone PARK; Lee Jae HYUN

    2014-01-01

    The hybrid functionally graded materials (FGM) of hydroxyapatite (HA), stainless steel 316L (SS316L) and carbon nanotubes (CNT) were synthesized for biomedical implants. Three different types of FGM were produced by the combination of SS316L and CNT to reinforce HA in discrete layers of FGM. In the first type of FGM, concentration of SS316L was varied from 10% to 40% (mass fraction) with an increment of 10% to reinforce micro HA. In the second type of FGM, 0.5% (mass fraction) functionalized CNT was added by maintaining the rest of composition as that of the first type of FGM. In the third type of FGM, mixture of micro and nano HA (mass ratio1:1) was used, keeping rest of composition similar to the second type of FGM. All types of FGM were subjected to uniaxial compaction and sintered by pressureless sintering technique at similar compaction and sintering parameters. The results show that the densification is enhanced with the addition of CNT and nanocrystalline HA in the FGM. Hardness and fracture toughness increase in both FGM reinforced with CNT, but the increase of the hardness and fracture toughness are more pronounced in FGM with micro and nanocrystalline HA.%利用羟基磷灰石(HA)、不锈钢316L(SS316L)和碳纳米管(CNT)制备生物医学植入体用混合功能梯度材料(FGM)。加入SS316L和CNT增强功能梯度材料离散层的HA制成三种不同类型的功能梯度材料。第一种功能梯度材料加入10%~40%(质量分数)的SS316L强化微米HA,浓度梯度为10%。第二种功能梯度材料,在第一种功能梯度材料的基础上加入0.5%(质量分数)的功能化碳纳米管。第三种功能梯度材料在第二种功能梯度材料的基础上加入微米HA和纳米HA(1:1)的混合物。所有类型的功能梯度材料在相似的压缩参数和烧结参数下,进行单轴压缩实验,并采用无压烧结技术进行烧结。结果表明,加入碳纳米管和纳米晶体HA提高了功能梯度材料的致密度。

  12. Research on New Technology for Extracting Precious Metals from Low Grade Gold Platinum Palladium Material%从低品位金铂钯物料中提取贵金属新工艺研究

    Institute of Scientific and Technical Information of China (English)

    马玉天; 陈大林; 郭晓辉; 潘从明; 张燕; 王立

    2014-01-01

    金川集团股份有限公司产生的低品位金钯铂物料为蒸残渣,通常是由贵金属精矿蒸馏分离锇、钌,水溶液氯化产生。现有蒸残渣处理工艺为反复氯化,由于受氯化效率的影响,依然有部分贵金属残留在外付渣中,造成贵金属流失。为提高贵金属回收率,金川集团贵金属冶炼厂组织进行了从蒸残渣中提纯贵金属的实验研究。通过长期实验探索,确定了蒸残渣氯化焙烧-盐酸浸出-有机溶剂萃取分离金铂钯的工艺路线。之后,又进行了工业化扩大试验,确定了最佳工艺技术条件,金、铂、钯直收率≥95%。与水溶液氯化工艺相比,该工艺具有贵金属直收率高、劳动强度低、生产周期短及生产成本低等特点。%The company produced platinum and palladium low grade gold material that was a kind of steamed residue,additionally,the steamed residue was produced during the process of precious metals concentrate distillation separation of osmium,ruthenium and aqueous chlorination.The existing steamed residue treatment technique of chloride repeatedly,because the effect of the efficiency of chloride,there were still some precious metal residues in the outside pay residue,has the problem of precious metals lossing.In order to improve the precious metal recovery,the smelting plant in the company completed a series of experimental studies on purification of precious metals from the steamed residue.Thus,after the experimental exploration for a long time, the steamed residue chloridizing roasting-hydrochloric acid leaching gold platinum palladium-organic solvent extraction separation process was determined.Then,the industrialized expanding test and the optimum technology conditions were also determined,meanwhile,the direct recovery rate was more than or equal to 95%during the technological process of gold,platinum and palladium.Compared with aqueous chlorination process,the method applied in the paper

  13. AXISYMMETRIC BENDING OF TWO-DIRECTIONAL FUNCTIONALLY GRADED CIRCULAR AND ANNULAR PLATES

    Institute of Scientific and Technical Information of China (English)

    Guojun Nie; Zheng Zhong

    2007-01-01

    Assuming the material properties varying with an exponential law both in the thickness and radial directions, axisymmetric bending of two-directional functionally graded circular and annular plates is studied using the semi-analytical numerical method in this paper. The deflections and stresses of the plates are presented. Numerical results show the well accuracy and convergence of the method. Compared with the finite element method, the semi-analytical numerical method is with great advantage in the computational efficiency. Moreover, study on axisymmetric bending of two-directional functionally graded annular plate shows that such plates have better performance than those made of isotropic homogeneous materials or one-directional functionally graded materials. Two-directional functionally graded material is a potential alternative to the one-directional functionally graded material. And the integrated design of materials and structures can really be achieved in two-directional functionally graded materials.

  14. Contemporary Gleason grading and novel Grade Groups in clinical practice.

    Science.gov (United States)

    Magi-Galluzzi, Cristina; Montironi, Rodolfo; Epstein, Jonathan I

    2016-09-01

    The Gleason grading system provides important information for guiding prostate cancer patients' management and prognostication. The grading system underwent significant modifications over the past decade. In 2005 and more recently in 2014, the International Society of Urological Pathology (ISUP) held two consensus conferences to update prostate cancer grading. Recently, five prognostic grade groups have been proposed to be used in parallel to the Gleason grading system. The purpose of this review is to highlight the key changes in the Gleason grading system and the utility of the grade groups to better reflect biologic behavior for both patients and clinicians. At the 2014 ISUP consensus conference, prostate cancer Gleason grading was updated and a previously proposed concept of five prognostic grade groups, from 1 to 5 was supported. The Grade Groups, used in parallel to the modified Gleason grading system, translate Gleason scores in five distinct risk categories where Grade Group 1 is defined as Gleason score 6 or less, Grade Group 2 as Gleason score 3 + 4 = 7, Grade Group 3 as Gleason score 4 + 3 = 7, Grade Group 4 as Gleason score 4 + 4 = 8, and Grade Group 5 as Gleason score 9/10. This 5-tiered grade group system better reflects biologic behavior and guides clinical care. The Grade Groups have been endorsed by the ISUP and the World Health Organization. The performance of the Grade Groups has been examined in several recent studies. This review summarizes developments over the last year in the use of grade groups and outlines their value in clinical practice.

  15. Graded-index magnonics

    Science.gov (United States)

    Davies, C. S.; Kruglyak, V. V.

    2015-10-01

    The wave solutions of the Landau-Lifshitz equation (spin waves) are characterized by some of the most complex and peculiar dispersion relations among all waves. For example, the spin-wave ("magnonic") dispersion can range from the parabolic law (typical for a quantum-mechanical electron) at short wavelengths to the nonanalytical linear type (typical for light and acoustic phonons) at long wavelengths. Moreover, the long-wavelength magnonic dispersion has a gap and is inherently anisotropic, being naturally negative for a range of relative orientations between the effective field and the spin-wave wave vector. Nonuniformities in the effective field and magnetization configurations enable the guiding and steering of spin waves in a deliberate manner and therefore represent landscapes of graded refractive index (graded magnonic index). By analogy to the fields of graded-index photonics and transformation optics, the studies of spin waves in graded magnonic landscapes can be united under the umbrella of the graded-index magnonics theme and are reviewed here with focus on the challenges and opportunities ahead of this exciting research direction.

  16. Serving Grades Over the Internet.

    Science.gov (United States)

    Harris, James K.

    This paper demonstrates a grade server that allows college students to access their grades over the Internet from the instructor's home page. Using a CGI (common gateway interface) program written in Visual Basic, the grades are read directly from an Excel spreadsheet and presented to the requester after he/she enters a password. The grade for…

  17. Functionally graded piezoelectric cantilever beam under load

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Z.F.; Chen, Y. [Beijing Jiaotong University, School of Civil Engineering, Beijing (China)

    2004-12-01

    In the present paper, the problem of a functionally graded piezoelectric cantilever beam subjected to different loadings is studied. The piezoelectric beam is characterized by continuously graded properties for one elastic parameter and the material density. A pair of stress and induction functions in the form of polynomials is proposed and determined. Based on these functions, a set of analytical solutions for the beam subjected to different loadings is obtained. As particular cases, series of solutions for some canonical problems can be directly obtained from the solutions of the present paper, such as for the problems of a piezoelectric cantilever beam with constant body force or without body forces, etc. (orig.)

  18. Modeling of vibration for functionally graded beams

    Directory of Open Access Journals (Sweden)

    Yiğit Gülsemay

    2016-01-01

    Full Text Available In this study, a vibration problem of Euler-Bernoulli beam manufactured with Functionally Graded Material (FGM, which is modelled by fourth-order partial differential equations with variable coefficients, is examined by using the Adomian Decomposition Method (ADM.The method is one of the useful and powerful methods which can be easily applied to linear and nonlinear initial and boundary value problems. As to functionally graded materials, they are composites mixed by two or more materials at a certain rate. This mixture at a certain rate is expressed with an exponential function in order to try to minimize singularities from transition between different surfaces of materials as much as possible. According to the structure of the ADM in terms of initial conditions of the problem, a Fourier series expansion method is used along with the ADM for the solution of simply supported functionally graded Euler-Bernoulli beams. Finally, by choosing an appropriate mixture rate for the material, the results are shown in figures and compared with those of a standard (homogeneous Euler-Bernoulli beam.

  19. Thermal performance of functionally graded parabolic annular fins having constant weight

    Energy Technology Data Exchange (ETDEWEB)

    Gaba, Vivek Kumar; Tiwari, Anil Kumar; Bhowmick, Shubhankar [National Institute of Technology Raipur, Raipur (India)

    2014-10-15

    The proposed work reports the performance of parabolic annular fins of constant weight made of functionally graded materials. The work involves computation of temperature gradient, efficiency and effectiveness of such fins and compares the performances for different functionally graded parabolic fin profiles obtained by varying grading parameters and profile parameters respectively keeping the weight of the fins constant. The functional grading of thermal conductivity is based on a power function of radial co-ordinate which consists of parameters, namely grading parameters, varying which different grading combinations are studied. A general second order ordinary differential equation has been derived for all the profiles and material grading. The efficiency and effectiveness of the annular fins of different profile and grading combinations have been calculated and plotted and the results reveal the dependence of fin performance on profile and grading parameter.

  20. Methods of graded rings

    CERN Document Server

    Nastasescu, Constantin

    2004-01-01

    The topic of this book, graded algebra, has developed in the past decade to a vast subject with new applications in noncommutative geometry and physics. Classical aspects relating to group actions and gradings have been complemented by new insights stemming from Hopf algebra theory. Old and new methods are presented in full detail and in a self-contained way. Graduate students as well as researchers in algebra, geometry, will find in this book a useful toolbox. Exercises, with hints for solution, provide a direct link to recent research publications. The book is suitable for courses on Master level or textbook for seminars.

  1. Automated grading of renal cell carcinoma using whole slide imaging

    Directory of Open Access Journals (Sweden)

    Fang-Cheng Yeh

    2014-01-01

    Full Text Available Introduction: Recent technology developments have demonstrated the benefit of using whole slide imaging (WSI in computer-aided diagnosis. In this paper, we explore the feasibility of using automatic WSI analysis to assist grading of clear cell renal cell carcinoma (RCC, which is a manual task traditionally performed by pathologists. Materials and Methods: Automatic WSI analysis was applied to 39 hematoxylin and eosin-stained digitized slides of clear cell RCC with varying grades. Kernel regression was used to estimate the spatial distribution of nuclear size across the entire slides. The analysis results were correlated with Fuhrman nuclear grades determined by pathologists. Results: The spatial distribution of nuclear size provided a panoramic view of the tissue sections. The distribution images facilitated locating regions of interest, such as high-grade regions and areas with necrosis. The statistical analysis showed that the maximum nuclear size was significantly different (P < 0.001 between low-grade (Grades I and II and high-grade tumors (Grades III and IV. The receiver operating characteristics analysis showed that the maximum nuclear size distinguished high-grade and low-grade tumors with a false positive rate of 0.2 and a true positive rate of 1.0. The area under the curve is 0.97. Conclusion: The automatic WSI analysis allows pathologists to see the spatial distribution of nuclei size inside the tumors. The maximum nuclear size can also be used to differentiate low-grade and high-grade clear cell RCC with good sensitivity and specificity. These data suggest that automatic WSI analysis may facilitate pathologic grading of renal tumors and reduce variability encountered with manual grading.

  2. Graded bandgap perovskite solar cells

    Science.gov (United States)

    Ergen, Onur; Gilbert, S. Matt; Pham, Thang; Turner, Sally J.; Tan, Mark Tian Zhi; Worsley, Marcus A.; Zettl, Alex

    2017-05-01

    Organic-inorganic halide perovskite materials have emerged as attractive alternatives to conventional solar cell building blocks. Their high light absorption coefficients and long diffusion lengths suggest high power conversion efficiencies, and indeed perovskite-based single bandgap and tandem solar cell designs have yielded impressive performances. One approach to further enhance solar spectrum utilization is the graded bandgap, but this has not been previously achieved for perovskites. In this study, we demonstrate graded bandgap perovskite solar cells with steady-state conversion efficiencies averaging 18.4%, with a best of 21.7%, all without reflective coatings. An analysis of the experimental data yields high fill factors of ~75% and high short-circuit current densities up to 42.1 mA cm-2. The cells are based on an architecture of two perovskite layers (CH3NH3SnI3 and CH3NH3PbI3-xBrx), incorporating GaN, monolayer hexagonal boron nitride, and graphene aerogel.

  3. A novel graded density impactor

    Science.gov (United States)

    Winter, R. E.; Cotton, M.; Harris, E. J.; Chapman, D. J.; Eakins, D.

    2014-05-01

    Ramp loading using graded-density-impactors as flyers in gas-gun-driven plate impact experiments can yield new and useful information about the equation of state and the strength properties of the loaded material. Selective Laser Melting, an additive manufacture technique, was used to manufacture a graded density flyer, termed the "bed of nails" (BON). A 2 mm thick × 100 mm diameter solid disc of stainless steel formed a base for an array of tapered spikes of length 6 mm and spaced 1 mm apart. The two experiments to test the concept were performed at impact velocities of 900 m/s and 1100 m/s using the 100 mm gas gun at the Institute of Shock Physics at Imperial College, London. In each experiment a BON flyer was impacted onto a copper buffer plate which helped to smooth out perturbations in the wave profile. The ramp delivered to the copper buffer was in turn transmitted to three tantalum targets of thicknesses 3, 5 and 7 mm, which were mounted in contact with the back face of the copper. Heterodyne velocimetry was used to measure the velocity-time history, at the back faces of the tantalum discs. The wave profiles display a smooth increase in velocity over a period of ~2.5 us, with no indication of a shock jump. The measured profiles have been analysed to generate a stress strain curve for tantalum. The results have been compared with the predictions of the Sandia National Laboratories hydrocode, CTH.

  4. “十二五”末江西增产“50亿斤粮”的出路与对策建议%Solutions and Countermeasures for "Increasing Grain Products by 2.5 Billion Kilogram" of Jiangxi in "Twelfth Five - years"

    Institute of Scientific and Technical Information of China (English)

    杨正威; 陈红萍; 颜龙安; 陆朝梁; 熊大建; 龙丘陵

    2012-01-01

    江西省“十二五”规划纲要中提出“十二五”期间我省“新增粮食产量50亿斤”,以策应国家“十二五”“增加1000亿斤粮食”的目标.本文分析了当前江西粮食综合生产能力及存在的问题、粮食生产中有利条件和面临的挑战,提出了“十二五”末江西增产“50亿斤粮”的出路与对策建议.%In order to support the country's target of "increasing the grain products by 50 billion kilogram" in "Twelfth Five -years" , the "Twelfth Five - years" planning program of Jiangxi province put forward "increasing the grain products by 2.5 billion kilogram" in "Twelfth Five-years". This paper analyzed the overall grain production capability, the existing problems, advantages and faced challenges in grain production of Jiangxi at present, and put forward the solutions and countermeasures for "increasing the grain products by 2.5 billion kilogram" of Jiangxi in "Twelfth Five -years".

  5. The Maximal Graded Left Quotient Algebra of a Graded Algebra

    Institute of Scientific and Technical Information of China (English)

    Gonzalo ARANDA PINO; Mercedes SILES MOLINA

    2006-01-01

    We construct the maximal graded left quotient algebra of every graded algebra A without homogeneous total right zero divisors as the direct limit of graded homomorphisms (of left A-modules)from graded dense left ideals of A into a graded left quotient algebra of A. In the case of a superalgebra,and with some extra hypothesis, we prove that the component in the neutral element of the group of the maximal graded left quotient algebra coincides with the maximal left quotient algebra of the component in the neutral element of the group of the superalgebra.

  6. An In-Depth Review of the Current Practica, Associated with Early Childhood through Twelfth Grade Special Education Programs, for the Benefit of Higher Education Programs, with an Emphasis in Obtaining a M.Ed. in Special Education

    Science.gov (United States)

    Cady, Jennifer

    2010-01-01

    In order to guide organizational growth in the Master's in Education with an emphasis in Special Education program, offered at Southwestern College, an in-depth qualitative study was conducted with participants from three specific realms located in the state of Kansas. Participants from the Kansas State Department of Education, Southwestern…

  7. Cutting Class Harms Grades

    Science.gov (United States)

    Taylor, Lewis A., III

    2012-01-01

    An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

  8. Social Studies: Grade 8.

    Science.gov (United States)

    Manitoba Dept. of Education, Winnipeg.

    This Manitoba (Canada) curriculum guide for eighth grade social studies students contains suggested teaching strategies and learning activities in four units covering: (1) life during prehistoric and early historic times; (2) ancient civilizations; (3) life in early modern Europe; and (4) life in the modern world. Each unit includes an overview,…

  9. Purpose-Driven Grading

    Science.gov (United States)

    Carlson, Jane A. K.; Kimpton, Ann

    2010-01-01

    Allowing students to improve their grade by revising their written work may help students learn to revise, but it gives them no incentive to turn in quality work from the start. This article proposes a way to invert the process, thereby teaching students how to revise, while enforcing a more disciplined approach to good writing. (Contains 3…

  10. Endangered Animals. Second Grade.

    Science.gov (United States)

    Popp, Marcia

    This second grade teaching unit centers on endangered animal species around the world. Questions addressed are: What is an endangered species? Why do animals become extinct? How do I feel about the problem? and What can I do? Students study the definition of endangered species and investigate whether it is a natural process. They explore topics…

  11. Production of Food Grade Yeasts

    Directory of Open Access Journals (Sweden)

    Argyro Bekatorou

    2006-01-01

    Full Text Available Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed.

  12. Grading of oral epithelial dysplasia: Points to ponder

    Directory of Open Access Journals (Sweden)

    K M Geetha

    2015-01-01

    Full Text Available Background: Over the years many grading systems have been put forward in an attempt to obtain objectivity in grading oral epithelial dysplasia (OED. However, despite these efforts variability remains unresolved. Our study aimed to evaluate the intra- and inter-observer variability in grading OED, using World Health Organization (WHO, Smith and Pindborg and Ljubljana grading systems and discuss the possible reasons for this variability if any. Materials and Methods: Three oral pathologists graded 50 slides of OED independently twice at a time interval of 3 months. Variability was evaluated by multivariate kappa analysis. Results: Intra-observer reproducibility ranged from moderate to good in WHO system, fair to moderate in Smith and Pindborg system and moderate to poor in Ljubljana grading system. Inter-observer agreement was found to be fair in WHO, poor in Smith and Pindborg system and poor to fair in Ljubljana grading systems. Intra-observer reproducibility of the dysplastic features in WHO system was good for all except the loss of polarity and basilar hyperplasia for first observer and enlarged nucleoli for the third observer. Inter-observer agreement was good for increased number of mitosis and nuclear hyperchromatism. Intra-observer reproducibility and inter-observer agreement were found to be best in the WHO grading system though variability within this system still existed. Conclusion: There is a need for an International body of pathologists to come to a consensus on a more definable grading system to resolve the issue of variability in grading dysplasia.

  13. Nondestructive Evaluation of Nuclear-Grade Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Dennis C. Kunerth; Timothy R. McJunkin

    2011-07-01

    Nondestructive Evaluation of Nuclear Grade Graphite Dennis C. Kunerth and Timothy R. McJunkin Idaho National Laboratory Idaho Falls, ID, 83415 This paper discusses the nondestructive evaluation of nuclear grade graphite performed at the Idaho National Laboratory. Graphite is a composite material highly dependent on the base material and manufacturing methods. As a result, material variations are expected within individual billets as well billet to billet and lot to lot. Several methods of evaluating the material have been explored. Particular technologies each provide a subset of information about the material. This paper focuses on techniques that are applicable to in-service inspection of nuclear energy plant components. Eddy current examination of the available surfaces provides information on potential near surface structural defects and although limited, ultrasonics can be utilized in conventional volumetric inspection. Material condition (e.g. micro-cracking and porosity induced by radiation and stress) can be derived from backscatter or acousto-ultrasound (AU) methods. Novel approaches utilizing phased array ultrasonics have been attempted to expand the abilities of AU techniques. By combining variable placement of apertures, angle and depth of focus, the techniques provide the potential to obtain parameters at various depths in the material. Initial results of the study and possible procedures for application of the techniques are discussed.

  14. Bending analysis of a functionally graded piezoelectric cantilever beam

    Institute of Scientific and Technical Information of China (English)

    YU Tao; ZHONG Zheng

    2007-01-01

    A new analysis based on Airy stress function method is presented for a functionally graded piezoelectric material cantilever beam.Assuming that the mechanical and electric properties of the material have the same variations along the thickness direction,a two-dimensional plane elasticity solution is obtained for the coupling electroelastic fields of the beam under different loadings.This solution will be useful in analyzing FGPM beam with arbitrary variations of material properties.The influences of the functionally graded material properties on the structural response of the beam subjected to different loads are also studied through numerical examples.

  15. Bending analysis of a functionally graded piezoelectric cantilever beam

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new analysis based on Airy stress function method is presented for a functionally graded piezoelectric material cantilever beam. Assuming that the mechanical and electric properties of the material have the same variations along the thickness direction, a two-dimensional plane elasticity solution is obtained for the coupling electroelastic fields of the beam under different loadings. This solution will be useful in analyzing FGPM beam with arbitrary variations of material properties. The influences of the functionally graded material properties on the structural response of the beam subjected to different loads are also studied through numerical examples.

  16. Cafeteria-Style Grading in General Chemistry

    Science.gov (United States)

    Goodwin, John A.; Gilbert, Brian D.

    2001-04-01

    Self-selected individual course-grade weighting schemes allow students personal choice of course components in the general chemistry sequence at Coastal Carolina University. With the availability of a wide range of commercial and academically produced pedagogical resources, students can select materials that best suit their own learning styles, social situations, and motivation level. Our students use a signed contract to indicate their preferred grade-weighting schemes for determination of the course grade. In doing so, they choose from course components that include peer-led team learning (PLTL) in the Workshop Chemistry (WSC) model, computer-assisted instruction (CAI) using the ChemSkill Builder (CSB) software, a variety of in-class quizzes and group problem-solving exercises, written exams, and the final written exam. Minimum percentage values are required of all components except WSC and CSB, which have been completely optional graded course components at CCU since the summer of 1999. Comparison of student success in the course and content learning suggests that the improvements observed with introduction of a gamut of activities increase even more when the cafeteria-style grading is implemented.

  17. Role of cytologic grading in prognostication of invasive breast carcinoma

    Directory of Open Access Journals (Sweden)

    Khan Nazoora

    2009-01-01

    Full Text Available Background: Evaluation of cytologic features is indispensable in the preoperative diagnosis and grading of infiltrating ductal breast carcinoma (CA in fine-needle aspiration cytology (FNAC material and this method can also provide additional information regarding intrinsic features of the tumor as well as its prognosis. Aim: This study has been done to evaluate comparatively the cytologic and histomorphologic grading of infiltrating ductal carcinoma of breast with specific reference to lymph node metastasis and its role in prognostication. Materials and Methods: Forty three patients who underwent FNAC and mastectomy for infiltrating ductal carcinoma were cytologically and histologically graded (employing Robinson′s cytologic grading system and Elston′s modification of Bloom-Richardson system, respectively. Statistical analysis was done employing ′z′ test and c2 test to compare the two grading system and to examine the degree of correlation between the cytologic and histologic grades. Multiple regression analysis was done to assess the significance of every cytologic and histologic parameter. All 43 cases, graded cyto-histologically were also evaluated for presence or absence of metastasis to the regional lymph nodes employing c2 test. Results: With histologic grade taken as the standard, cytology was found to be fairly comparable, for grading breast carcinoma (overall sensitivity 89.1%, specificity 100%. Further comparison of the two grading systems by Z-test showed that difference between the cytologic and histologic grading was insignificant in all the three grade (p > 0.05. Of the six parameters studied, cell dissociation, nucleoli and chromatin pattern were the most influential features (p < 0.001. The statistically significant difference (p < 0.001 was found in incidences of axillary lymph node metastatic rate in three cytologic grades (15.4% in grade I vs. 83.3% in grade III as well. Conclusions: Apart from being simple and

  18. Material Development and Meeting Learner's Need

    Science.gov (United States)

    Aydin, Abdullah

    2013-01-01

    In this study, the aim was to show that learners' needs can be met using simple and cheap materials that can be found everywhere in 9th to 11th grade Chemistry courses. To this end, materials were developed using simple everyday life materials for 9th to 11th grade Chemistry courses. In the research, the project method was employed. The study was…

  19. Write More, Grade Less: Five Practices for Effectively Grading Writing

    Science.gov (United States)

    Lucas, Lisa

    2012-01-01

    One of the dilemmas that teachers frequently face is grading student papers. As a teacher, the author regularly reads research regarding instructional practices, grading, and assessment, but struggled to translate theory into practice in her own classroom. The intent of this article is to share one method of instructing and grading writing that…

  20. Elasticity solutions for functionally graded plates in cylindrical bending

    Institute of Scientific and Technical Information of China (English)

    YANG Bo; DING Hao-jiang; CHEN Wei-qiu

    2008-01-01

    The plate theory of functionally graded materials suggested by Mian and Spencer is extended to analyze the cylindrical bending problem of a functionally graded rectangular plate subject to uniform load. The expansion formula for displacements is adopted. While keeping the assumption that the material parameters can vary along the thickness direction in an arbitrary fashion, this paper considers orthotropic materials rather than isotropic materials. In addition, the traction-free condition on the top surface is replaced with the condition of uniform load applied on the top surface. The plate theory for the particular case of cylindrical bending is presented by considering an infinite extent in the y-direction. Effects of boundary conditions and material inhomogeneity on the static response of functionally graded plates are investigated through a numerical example.

  1. “十二五”期间陕西人身保险市场需求变化研究%Analysis of the Changes in Life Insurance Market Demand of Shaanxi Province During the Twelfth Five-Year

    Institute of Scientific and Technical Information of China (English)

    杨馥; 刘珺

    2012-01-01

    The development of life insurance market in Shaanxi Province will be promoted by the substainable development of Shaanxi's economy and society during the Twelfth Five-Year.The demand of life insurance is key index of the development of lif insurance market.The demand of life insurance market is measured by life insurance premiums in Shaanxi.Based on the data in 1990-2009,this paper provides positive analysis on the demand of life insurance market in Shaanxi by cointegration and logarithm function-model.Following the results,it predicts the trends of life insurance market demands in Shanxi during the Twelfth Five-Year plan,to provide theory basis for life insurance market planning.%"十二五"期间,陕西省经济的持续发展为陕西省人身保险市场的发展提供了有利契机。人身保险需求是度量人身保险市场发展状况的重要指标。文章以陕西省人身保险保费收入作为衡量人身保险市场需求的变量,参考保险密度和保险深度等指标,选取1990—2009年的相关数据,采用协整检验,利用自然对数模型对陕西省人身保险市场需求进行实证分析,并据此对"十二五"期间陕西省人身保险市场需求变化趋势进行预测,旨在为陕西省人身保险业规划提供理论依据。

  2. Determinants for grading Malaysian rice

    Science.gov (United States)

    ChePa, Noraziah; Yusoff, Nooraini; Ahmad, Norhayati

    2016-08-01

    Due to un-uniformity of rice grading practices in Malaysia, zones which actively producing rice in Malaysia are using their own way of grading rice. Rice grading is important in determining rice quality and its subsequent price in the market. It is an important process applied in the rice production industry with the purpose of ensuring that the rice produced for the market meets the quality requirements of consumer. Two important aspects that need to be considered in determining rice grades are grading technique and determinants to be used for grading (usually referred as rice attributes). This article proposes the list of determinants to be used in grading Malaysian rice. Determinants were explored through combination of extensive literature review and series of interview with the domain experts and practitioners. The proposed determinants are believed to be beneficial to BERNAS in improving the current Malaysian rice grading process.

  3. Math. Grades 3-6, Forms A and B. West Bloomfield School District Outcome Based Mastery Learning Program.

    Science.gov (United States)

    West Bloomfield Schools, MI.

    These materials contain the test booklets and answer keys to the mathematics mastery program of the West Bloomfield Schools (Michigan). Two booklets, forms A and B, were developed for each grade level from grade 3 through grade 6. The answer keys are on separate sheets. The mastery program is based on textbook and supplemental materials. (TW)

  4. Inflated Grades, Enrollments & Budgets

    Directory of Open Access Journals (Sweden)

    J. E. Stone

    1995-06-01

    Full Text Available Reports of the past 13 years that call attention to deficient academic standards in American higher education are enumerated. Particular attention is given the Wingspread Group's recent An American Imperative: Higher Expectations for Higher Education. Low academic standards, grade inflation, and budgetary incentives for increased enrollment are analyzed and a call is made for research at the state level. Reported trends in achievement and GPAs are extrapolated to Tennessee and combined with local data to support the inference that 15% of the state's present day college graduates would not have earned a diploma by mid 1960s standards. A conspicuous lack of interest by public oversight bodies is noted despite a growing public awareness of low academic expectations and lenient grading and an implicit budgetary impact of over $100 million. Various academic policies and the dynamics of bureaucratic control are discussed in relationship to the maintenance of academic standards. The disincentives for challenging course requirements and responsible grading are examined, and the growing movement to address academic quality issues through better training and supervision of faculty are critiqued. Recommendations that would encourage renewed academic integrity and make learning outcomes visible to students, parents, employers, and the taxpaying public are offered and briefly discussed.

  5. Modeling of functionally graded piezoelectric ultrasonic transducers.

    Science.gov (United States)

    Rubio, Wilfredo Montealegre; Buiochi, Flávio; Adamowski, Julio Cezar; Silva, Emílio Carlos Nelli

    2009-05-01

    The application of functionally graded material (FGM) concept to piezoelectric transducers allows the design of composite transducers without interfaces, due to the continuous change of property values. Thus, large improvements can be achieved, as reduction of stress concentration, increasing of bonding strength, and bandwidth. This work proposes to design and to model FGM piezoelectric transducers and to compare their performance with non-FGM ones. Analytical and finite element (FE) modeling of FGM piezoelectric transducers radiating a plane pressure wave in fluid medium are developed and their results are compared. The ANSYS software is used for the FE modeling. The analytical model is based on FGM-equivalent acoustic transmission-line model, which is implemented using MATLAB software. Two cases are considered: (i) the transducer emits a pressure wave in water and it is composed of a graded piezoceramic disk, and backing and matching layers made of homogeneous materials; (ii) the transducer has no backing and matching layer; in this case, no external load is simulated. Time and frequency pressure responses are obtained through a transient analysis. The material properties are graded along thickness direction. Linear and exponential gradation functions are implemented to illustrate the influence of gradation on the transducer pressure response, electrical impedance, and resonance frequencies.

  6. ROMI 3.1 Least-cost lumber grade mix solver using open source statistical software

    Science.gov (United States)

    Rebecca A. Buck; Urs Buehlmann; R. Edward. Thomas

    2010-01-01

    The least-cost lumber grade mix solution has been a topic of interest to both industry and academia for many years due to its potential to help wood processing operations reduce costs. A least-cost lumber grade mix solver is a rough mill decision support system that describes the lumber grade or grade mix needed to minimize raw material or total production cost (raw...

  7. Improvement of ASME NH for Grade 91

    Energy Technology Data Exchange (ETDEWEB)

    Bernard Riou

    2007-10-09

    This report has been prepared in the context of Task 3 of the ASME/DOE Gen IV material project. It has been identified that creep-fatigue evaluation procedures presently available in ASME (1) and RCC-MR (2) have been mainly developed for austenitic stainless steels and may not be suitable for cyclic softening materials such as mod 9 Cr 1 Mo steel (grade 91). The aim of this document is, starting from experimental test results, to perform a review of the procedures and, if necessary, provide recommendations for their improvements.

  8. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  9. 考虑缺陷的轴压功能梯度材料圆柱壳的弹塑性屈曲分析%Analysis of elastic and plastic buckling for axial loaded cylindrical shells made of functionally graded materials under imperfection

    Institute of Scientific and Technical Information of China (English)

    吴钰川

    2015-01-01

    In view of the problem of elastic and plastic buckling for axial loaded the cylindrical shells made of functionally graded materials,we employ the finite element software ABAQUS to conduct a nu-merical simulation and analysis. The laminated model and the model of TTO are used in the analysis, which takes full consideration of the physical characteristic of the material,namely,the influence of the physical nonlinearity and the geometrical nonlinear buckling. The influence of the shell thickness and component parameters on the buckling critical state is analyzed through calculating the critical load and deformation pattern of elastic-plastic functionally graded material cylindrical shell buckling.%针对功能梯度材料圆柱壳的考虑缺陷的弹塑性屈曲问题,采用有限元软件ABAQUS进行了数值模拟与分析。分析中采用叠层模型和TTO模型,充分考虑了材料的物性特性,即材料的物理非线性和前屈曲几何非线性的影响。计算得到缺陷作用下的弹塑性功能梯度材料圆柱壳的屈曲临界荷载和变形模式,研究了壳体厚度、组分参数对屈曲临界状态的影响。

  10. 30 CFR 816.102 - Backfilling and grading: General requirements.

    Science.gov (United States)

    2010-07-01

    ..., acid- and toxic-forming materials, and combustible materials exposed, used, or produced during mining.... 816.102 Section 816.102 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT...-SURFACE MINING ACTIVITIES § 816.102 Backfilling and grading: General requirements. (a) Disturbed...

  11. The People of South Asia [Grades 6-8].

    Science.gov (United States)

    Adams, George; And Others

    A resource book for grades 6-8 contains materials to enrich a unit on South Asia. Material is divided into 13 sections. Sections 1-4 outline the rationale, goals, and objectives of the unit. Emphasis is placed on providing background for the understanding of South Asian cultural groups in the United States. Ten objectives are listed, including the…

  12. 7 CFR 810.1404 - Grades and grade requirements for sorghum.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Grades and grade requirements for sorghum. 810.1404... OFFICIAL UNITED STATES STANDARDS FOR GRAIN United States Standards for Sorghum >grades and Grade Requirements § 810.1404 Grades and grade requirements for sorghum. Grading factors Grades U.S. Nos. 1 1 2 3...

  13. Speciation, liquid-liquid extraction, sequential separation, preconcentration, transport and ICP-AES determination of Cr(III), Mo(VI) and W(VI) with calix-crown hydroxamic acid in high purity grade materials and environmental samples.

    Science.gov (United States)

    Agrawal, Y K; Sharma, K R

    2005-07-15

    A new functionalized calix[6]crown hydroxamic acid is reported for the speciation, liquid-liquid extraction, sequential separation and trace determination of Cr(III), Mo(VI) and W(VI). Chromium(III), molybdenum(VI) and tungsten(VI) are extracted at pH 4.5, 1.5M HCl and 6.0M HCl, respectively with calixcrown hydroxamic acid (37,38,39,40,41,42-hexahydroxy7,25,31-calix[6]crown hydroxamic acid) in chloroform in presence of large number of cations and anions. The extraction mechanism is investigated. The various extraction parameters, appropriate pH/M HCl, choice of solvent, effect of the reagent concentration, temperature and distribution constant have been studied. The speciation, preconcentration and kinetic of transport has been investigated. The maximum transport is observed 35, 45 and 30min for chromium(III), molybdenum(VI) and tungsten(IV), respectively. For trace determination the extracts were directly inserted into the plasma for inductively coupled plasma atomic emission spectrometry, ICP-AES, measurements of chromium, molybdenum and tungsten which increase the sensitivity by 30-fold, with detection limits of 3ngml(-1). The method is applied for the determination of chromium, molybdenum and tungsten in high purity grade ores, biological and environmental samples. The chromium was recovered from the effluent of electroplating industries.

  14. Engineering graded tissue interfaces.

    Science.gov (United States)

    Phillips, Jennifer E; Burns, Kellie L; Le Doux, Joseph M; Guldberg, Robert E; García, Andrés J

    2008-08-26

    Interfacial zones between tissues provide specialized, transitional junctions central to normal tissue function. Regenerative medicine strategies focused on multiple cell types and/or bi/tri-layered scaffolds do not provide continuously graded interfaces, severely limiting the integration and biological performance of engineered tissue substitutes. Inspired by the bone-soft tissue interface, we describe a biomaterial-mediated gene transfer strategy for spatially regulated genetic modification and differentiation of primary dermal fibroblasts within tissue-engineered constructs. We demonstrate that zonal organization of osteoblastic and fibroblastic cellular phenotypes can be engineered by a simple, one-step seeding of fibroblasts onto scaffolds containing a spatial distribution of retrovirus encoding the osteogenic transcription factor Runx2/Cbfa1. Gradients of immobilized retrovirus, achieved via deposition of controlled poly(L-lysine) densities, resulted in spatial patterns of transcription factor expression, osteoblastic differentiation, and mineralized matrix deposition. Notably, this graded distribution of mineral deposition and mechanical properties was maintained when implanted in vivo in an ectopic site. Development of this facile and robust strategy is significant toward the regeneration of continuous interfacial zones that mimic the cellular and microstructural characteristics of native tissue.

  15. Assessment of flexural properties of different grade dimension lumber by ultrasonic technique

    Institute of Scientific and Technical Information of China (English)

    JIANG Jing-hui; LU Jian-xiong; REN Hai-qing; LONG Chao; LUO Xiu-qin

    2007-01-01

    The dimension lumber (45mm×90mm×3700mm) of plantation Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) was graded to four different classes as SS, No.1, No.2 and No.3, according to national lumber grades authority (NLGA) for structure light framing and structure joists and planks. The properties of apparent density was determined at 15% moisture content, bending strength and stiffness were tested according to American Society for Testing and Materials (ASTM) D 198-99, and dynamic modulus of elasticity (Eusw) was measured by ultrasonic technique, for predicting the flexural properties of different grade lumbers. The results showed that Eusw was larger than the static MOE. The relationship between Eusw and static MOE was significant at 0.01 level, and the determination coefficients (R2) of the four grade lumbers followed the sequence as R2No.2 (0.616)> R2ss (0.567)> R2No.1 (0.366)> R2No.3 (0.137). The R2 of Eusw and MOR were lower than that of the Etru and MOR for each grade. The Eusw of all the grade lumbers, except No.3-grade, had significant correlation with the static MOE and MOR, thus the bending strength of those grade lumbers can be estimated by the E The Etru values of four grade lumbers followed a sequence as No.2-grade (10.701 Gpa) > SS-grade (10.359 Gpa) > No.l-grade (9.840 Gpa) > No.3-grade (9.554 Gpa). For the same grade dimension lumber, its Eusw value was larger than static MOE. Mean values of MOR for four grade lumbers follow a sequence as No.2-grade (48.67 Mpa) > SS-grade (48.16 Mpa) > No.3-grade (46.55 Mpa) > No.1-grade (43.39MPa).

  16. Mitigating the Effects of Negative Stereotyping of Aging and the Elderly in Primary Grade Reading Instruction.

    Science.gov (United States)

    Gutknecht, Bruce

    1991-01-01

    Discusses depictions of aging and the elderly in primary grade reading instructional materials. Investigates the attitudes of primary grade students toward aging and the elderly. Suggests instructional approaches and materials that can mitigate the effects of negative stereotyping of aging and the elderly. (RS)

  17. Mitigating the Effects of Negative Stereotyping of Aging and the Elderly in Primary Grade Reading Instruction.

    Science.gov (United States)

    Gutknecht, Bruce

    1991-01-01

    Discusses depictions of aging and the elderly in primary grade reading instructional materials. Investigates the attitudes of primary grade students toward aging and the elderly. Suggests instructional approaches and materials that can mitigate the effects of negative stereotyping of aging and the elderly. (RS)

  18. Vesicoureteric reflux: Evaluation by bladder volume graded direct radionuclide cystogram

    OpenAIRE

    Agrawal Vikesh; Rangarajan Venkatesh; Kamath Tejaswini; Borwankar S

    2009-01-01

    Aim : Evaluation of vesicoureteric reflux (VUR) in children by bladder volume graded direct radionuclide cystogram (BVG DRC). This technique allows detection of VUR at different bladder volume grades. Materials and Methods : In this prospective study, 33 patients (66 renal units) with suspected vesicoureteric reflux were subjected to a voiding cystourethrogram (VCUG) and BVG DRC. The patients were assessed further with radioisotope renal scans for renal cortical scars. Results : Twenty-two...

  19. CREEP BEHAVIOR OF VISCOELASTIC FUNCTIONALLY GRADED MATERIALS AND STRUCTURES IN THERMAL ENVIRONMENT%热环境中黏弹性功能梯度材料及其结构的蠕变

    Institute of Scientific and Technical Information of China (English)

    彭凡; 顾勇军; 马庆镇

    2012-01-01

    Based on classical correspondence principle, Mori-Tanaka and other micromechanical approaches are extended to treat the case of linear viscoelasticity in the constant thermal environment. The relaxation modulus and coefficient of thermal expansion of linearly viscoelastic FGMs are given directly in Laplace phase space, and multi-dimensional viscoelastic constitutive relation coupling thermal strain is constructed through considering the weak time-dependent feature of Poisson's ratio. Following the above work, the problem of axial symmetrical bending of viscoelastic functionally graded circular cylindrical thin shells is solved. The steady temperature field is determined taking into account of the temperature dependence of thermal and mechanical parameters. The analytic solution is derived in phase space and the creep deflection is obtained by means of Laplace numerical inversion. It is shown that the thermal effect is obvious at initial creep stage, but abates with the increase of time due to the relaxation of the thermal stresses, and the constraint effect for hinged ends is more prominent than that of clamped ends on the deflection near ends when circular cylindrical thin shell is subjected to axial compression. It is expected to give the general approach to analyze the creep deformation of viscoelastic functionally graded structures with arbitrary distribution of volume content under thermal and mechanical loading by solving above problem of axial symmetrical bending.%基于经典的对应原理,将Mori-Tanaka方法等细观力学结果推广于定常温度环境下的黏弹性情形.根据泊松比与时间呈弱相关的特点,给出Laplace象空间中功能梯度材料的松弛模最和热膨胀系数,并直接建立耦合热应变的多维黏弹性本构关系.在此基础上,求解黏弹性功能梯度网柱薄壳在热环境中的轴对称弯曲蠕变变形问题.考虑材料热物参数的温度相关性,首

  20. The evolving Gleason grading system.

    Science.gov (United States)

    Chen, Ni; Zhou, Qiao

    2016-02-01

    The Gleason grading system for prostate adenocarcinoma has evolved from its original scheme established in the 1960s-1970s, to a significantly modified system after two major consensus meetings conducted by the International Society of Urologic Pathology (ISUP) in 2005 and 2014, respectively. The Gleason grading system has been incorporated into the WHO classification of prostate cancer, the AJCC/UICC staging system, and the NCCN guidelines as one of the key factors in treatment decision. Both pathologists and clinicians need to fully understand the principles and practice of this grading system. We here briefly review the historical aspects of the original scheme and the recent developments of Gleason grading system, focusing on major changes over the years that resulted in the modern Gleason grading system, which has led to a new "Grade Group" system proposed by the 2014 ISUP consensus, and adopted by the 2016 WHO classification of tumours of the prostate.