The effect of a short-term high-intensity circuit training program on work capacity, body composition, and blood profiles in sedentary obese men: a pilot study.

Science.gov (United States)

Miller, Matthew B; Pearcey, Gregory E P; Cahill, Farrell; McCarthy, Heather; Stratton, Shane B D; Noftall, Jennifer C; Buckle, Steven; Basset, Fabien A; Sun, Guang; Button, Duane C

2014-01-01

The objective of this study was to determine how a high-intensity circuit-training (HICT) program affects key physiological health markers in sedentary obese men. Eight obese (body fat percentage >26%) males completed a four-week HICT program, consisting of three 30-minute exercise sessions per week, for a total of 6 hours of exercise. Participants' heart rate (HR), blood pressure (BP), rating of perceived exertion, total work (TW), and time to completion were measured each exercise session, body composition was measured before and after HICT, and fasting blood samples were measured before throughout, and after HICT program. Blood sample measurements included total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, glucose, and insulin. Data were analyzed by paired t-tests and one-way ANOVA with repeated measures. Statistical significance was set to P < 0.05. Data analyses revealed significant (P < 0.05) improvements in resting HR (16% decrease), systolic BP (5.5% decrease), TW (50.7%), fat tissue percentage (3.6%), lean muscle tissue percentage (2%), cholesterol (13%), triacylglycerol (37%), and insulin (18%) levels from before to after HICT program. Overall, sedentary obese males experienced a significant improvement in biochemical, physical, and body composition characteristics from a HICT program that was only 6 hours of the total exercise.

Computer program determines chemical composition of physical system at equilibrium

Science.gov (United States)

Kwong, S. S.

1966-01-01

FORTRAN 4 digital computer program calculates equilibrium composition of complex, multiphase chemical systems. This is a free energy minimization method with solution of the problem reduced to mathematical operations, without concern for the chemistry involved. Also certain thermodynamic properties are determined as byproducts of the main calculations.

CHAP: a composite nuclear plant simulation program applied to the 3000 MW(t) HTGR

International Nuclear Information System (INIS)

Secker, P.A.; Bailey, P.G.; Gilbert, J.S.; Willcutt, G.J.E. Jr.; Vigil, J.C.

1977-01-01

The Composite HTGR Analysis Program (CHAP) is a general systems analysis program which has been developed at LASL. The program is being used for simulating large HTGR nuclear power plant operation and accident transients. The general features and analytical methods of the CHAP program are discussed. Features of the large HTGR model and results of model transients are also presented

DETERMINING THE COMPOSITION OF HIGH TEMPERATURE COMBUSTION PRODUCTS OF FOSSIL FUEL BASED ON VARIATIONAL PRINCIPLES AND GEOMETRIC PROGRAMMING

Directory of Open Access Journals (Sweden)

Velibor V Vujović

2011-01-01

Full Text Available This paper presents the algorithm and results of a computer program for calculation of complex equilibrium composition for the high temperature fossil fuel combustion products. The method of determining the composition of high temperatures combustion products at the temperatures appearing in the open cycle MHD power generation is given. The determination of combustion product composition is based on minimization of the Gibbs free energy. The number of equations to be solved is reduced by using variational principles and a method of geometric programming and is equal to the sum of the numbers of elements and phases. A short description of the computer program for the calculation of the composition and an example of the results are also given.

Development of APDL program for analysis of composite material multicell beams

International Nuclear Information System (INIS)

Tariq, M.M.; Pasha, M.; Ahmed, M.N.; Munir, A.

2011-01-01

Comparison of finite elements and comparison of ANSYS with MSC Patran Nastran, for analysis of composite material multicell beams, is the main idea of this paper. The Finite Element Analysis (FEA) is a valuable tool of modeling and simulation in development, processing, production and application of modern hi-tech materials and structures for reliable design. Multicell beams have important industrial applications in the automotive and aerospace sectors. ANSYS Parametric Design Language (APDL) is an important language in parametric modeling and analysis of structures with simple to complex geometry. Its major advantage is virtual prototyping which can be used to analyze and compare different materials. This work introduces core techniques required for APDL using the case study of composite multicell beams subjected to constrained torsional loading. The published results using MSC NASTRAN have been verified using ANSYS and the corresponding arising issues and notes are the focus of this research study. The details of geometry, material and boundary conditions have been explained in order to construct Finite Element (FE) model. This FE model was simulated several times in ANSYS by the authors using various options of APDL language. A step-wise flowchart was used to detect and reduce problems in iterations of analysis in APDL programming. Results of FEA largely depend on FE model and software used. These issues become prominent while trying to verify results of MSC NASTRAN with ANSYS. The author has introduced three error criteria to select an equivalent finite element of one FEA package (ANSYS) for an equivalent element of other FEA package (MSC NASTRAN). These criteria are the relative error criterion, the absolute error criterion and the combined error criterion. The results from this research provide an insight into finite elements for reliability in design of composite materials. The practical milestones for research to develop FE model and APDL programs related

The Glasgow Parallel Reduction Machine: Programming Shared-memory Many-core Systems using Parallel Task Composition

Directory of Open Access Journals (Sweden)

Ashkan Tousimojarad

2013-12-01

Full Text Available We present the Glasgow Parallel Reduction Machine (GPRM, a novel, flexible framework for parallel task-composition based many-core programming. We allow the programmer to structure programs into task code, written as C++ classes, and communication code, written in a restricted subset of C++ with functional semantics and parallel evaluation. In this paper we discuss the GPRM, the virtual machine framework that enables the parallel task composition approach. We focus the discussion on GPIR, the functional language used as the intermediate representation of the bytecode running on the GPRM. Using examples in this language we show the flexibility and power of our task composition framework. We demonstrate the potential using an implementation of a merge sort algorithm on a 64-core Tilera processor, as well as on a conventional Intel quad-core processor and an AMD 48-core processor system. We also compare our framework with OpenMP tasks in a parallel pointer chasing algorithm running on the Tilera processor. Our results show that the GPRM programs outperform the corresponding OpenMP codes on all test platforms, and can greatly facilitate writing of parallel programs, in particular non-data parallel algorithms such as reductions.

Addendum to: Derivation of in situ opalinus clay porewater compositions from experimental and geochemical modelling studies

International Nuclear Information System (INIS)

Bradbury, M.H.; Baeyens; Pearson, F.J.; Berner, U.

1998-01-01

As part of the synthesis of water chemistry studies within the hydrochemical program at Mont Terri (Switzerland), a reexamination of the modelling method showed that it should lead to a range of water compositions rather than to a single composition. The single composition resulted from two compensating oversights, a theoretical one and a modelling one. These are discussed in this Addendum. (author)

A Study of the Utilization of Advanced Composites in Fuselage Structures of Commercial Aircraft

Science.gov (United States)

Watts, D. J.; Sumida, P. T.; Bunin, B. L.; Janicki, G. S.; Walker, J. V.; Fox, B. R.

1985-01-01

A study was conducted to define the technology and data needed to support the introduction of advanced composites in the future production of fuselage structure in large transport aircraft. Fuselage structures of six candidate airplanes were evaluated for the baseline component. The MD-100 was selected on the basis of its representation of 1990s fuselage structure, an available data base, its impact on the schedule and cost of the development program, and its availability and suitability for flight service evaluation. Acceptance criteria were defined, technology issues were identified, and a composite fuselage technology development plan, including full-scale tests, was identified. The plan was based on composite materials to be available in the mid to late 1980s. Program resources required to develop composite fuselage technology are estimated at a rough order of magnitude to be 877 man-years exclusive of the bird strike and impact dynamic test components. A conceptual composite fuselage was designed, retaining the basic MD-100 structural arrangement for doors, windows, wing, wheel wells, cockpit enclosure, major bulkheads, etc., resulting in a 32 percent weight savings.

Safer Roads: Comparisons Between Road Assessment Program and Composite Road Safety Index Method

Directory of Open Access Journals (Sweden)

Mohd Razelan Intan Suhana

2017-01-01

Full Text Available In most countries, crash statistics have becoming very crucial in evaluating road’s safety level. In Malaysia, these data are very important in deciding crash-prone areas known as black spot where specific road improvements plan will be proposed. However due to the unavailability of reliable crash data in many developing countries, appropriate road maintenance measures are facing great troubles. In light of that, several proactive methods in defining road’s safety level such as Road Assessment Program (RAP have emerged. This research aim to compare two proactive methods that have been tested in Malaysian roads ; road assessment program and road environment risk index which was developed based on composite index theory in defining road’s safety level. Composite road environment risk index was combining several crucial environment indicators, assigning weight and aggregating the individual index together to form a single value representing the road’s safety level. Based on the results, it can be concluded that both road assessment program and composite road environment risk index are contradicted in six different ways such as type of speed used, type of analysis used and their final outcomes. However, with an aim to promote safer roads, these two methods can be used concurrently as the outcomes in both methods seems to fulfil each other’s gap very well.

A quantitative study of a physics-first pilot program

Energy Technology Data Exchange (ETDEWEB)

Pasero, Spencer Lee; /Northern Illinois U.

2008-09-01

Hundreds of high schools around the United States have inverted the traditional core sequence of high school science courses, putting physics first, followed by chemistry, and then biology. A quarter-century of theory, opinion, and anecdote are available, but the literature lacks empirical evidence of the effects of the program. The current study was designed to investigate the effects of the program on science achievement gain, growth in attitude toward science, and growth in understanding of the nature of scientific knowledge. One hundred eighty-five honor students participated in this quasi-experiment, self-selecting into either the traditional or inverted sequence. Students took the Explore test as freshmen, and the Plan test as sophomores. Gain scores were calculated for the composite scores and for the science and mathematics subscale scores. A two-factor analysis of variance (ANOVA) on course sequence and cohort showed significantly greater composite score gains by students taking the inverted sequence. Participants were administered surveys measuring attitude toward science and understanding of the nature of scientific knowledge twice per year. A multilevel growth model, compared across program groups, did not show any significant effect of the inverted sequence on either attitude or understanding of the nature of scientific knowledge. The sole significant parameter showed a decline in student attitude independent of course sequence toward science over the first two years of high school. The results of this study support the theory that moving physics to the front of the science sequence can improve achievement. The importance of the composite gain score on tests vertically aligned with the high-stakes ACT is discussed, and several ideas for extensions of the current study are offered.

MAXIMSUPER: a computer program to assist in the design of multifilamentary superconducting composites

International Nuclear Information System (INIS)

Hoard, R.W.; Scanlan, R.M.; Hirzel, D.G.

1979-01-01

The strain degradation of critical current density has been analytically and experimentally investigated for multifilamentary superconducting composites produced in a bronze core geometry. Analytic results were obtained from a computer program (MAXIMSUPER) which predicts the stresses and strains in composites as a result of thermal and axial loading. Tensile test data for Nb 3 Sn are described. It is believed that the strain dependence of the critical current found in Nb 3 Sn is due to strain enhanced martensitic transformation

Program Evaluation - Automotive Lightweighting Materials Program Research and Development Projects Assessment of Benefits - Case Studies No. 2

Energy Technology Data Exchange (ETDEWEB)

Das, S.

2003-01-23

This report is the second of a series of studies to evaluate research and development (R&D) projects funded by the Automotive Lightweighting Materials (ALM) Program of the Office of Advanced Automotive Technologies (OAAT) of the U.S. Department of Energy (DOE). The objectives of the program evaluation are to assess short-run outputs and long-run outcomes that may be attributable to the ALM R&D projects. The ALM program focuses on the development and validation of advanced technologies that significantly reduce automotive vehicle body and chassis weight without compromising other attributes such as safety, performance, recyclability, and cost. Funded projects range from fundamental materials science research to applied research in production environments. Collaborators on these projects include national laboratories, universities, and private sector firms, such as leading automobile manufacturers and their suppliers. Three ALM R&D projects were chosen for this evaluation: Design and Product Optimization for Cast Light Metals, Durability of Lightweight Composite Structures, and Rapid Tooling for Functional Prototyping of Metal Mold Processes. These projects were chosen because they have already been completed. The first project resulted in development of a comprehensive cast light metal property database, an automotive application design guide, computerized predictive models, process monitoring sensors, and quality assurance methods. The second project, the durability of lightweight composite structures, produced durability-based design criteria documents, predictive models for creep deformation, and minimum test requirements and suggested test methods for establishing durability properties and characteristics of random glass-fiber composites for automotive structural composites. The durability project supported Focal Project II, a validation activity that demonstrates ALM program goals and reduces the lead time for bringing new technology into the marketplace. Focal

Floating Foundations: "Kairos," Community, and a Composition Program in Post-Katrina New Orleans

Science.gov (United States)

Johnson, T. R.; Letter, Joe; Livingston, Judith Kemerait

2009-01-01

The authors describe their individual and collective experiences reconstructing their New Orleans-based university composition program in the aftermath of Hurricane Katrina. They emphasize how the concept of "floating foundations" helps account for changes in their students' interests, and they suggest that this idea is applicable to the…

The study of fix composite panel and steel plates on testing stand

Science.gov (United States)

Wróbel, A.; Płaczek, M.; Wachna, M.

2016-08-01

In this paper the practical possibilities of strength verification analysis of composite materials used in the manufacture of selected components of railway wagons are presented. Real laboratory stand for measurements in a scale controlled by PLC controller were made. The study of different types of connections of composite materials with sheet metal is presented. In one of the chapter of this paper principles construction of testing stand with pneumatic cylinder were presented. Mainly checking of displacements and stresses generated on the sheet as a result of pneumatic actuators load for composite boards was carried out. The use of the controller with operating panel allows to easy programming testing cycle. The user can define the force generated by the actuator by change of air pressure in cylinder. Additionally the location of acting cylinders and their jump can be changed by operator. The examination of the volume displacements was done by displacement sensor, and the tensile strain gauge. All parameters are written in CatmanEasy - data acquisition software. This article presents the study of stresses and displacements in the composite plates joined with sheet metal, in summary of this article, the authors compare the obtained results with the computer simulation results in the article: "Simulation of stresses in an innovative combination of composite with sheet".

NASA Small Business Innovation Research Program. Composite List of Projects, 1983 to 1989

Science.gov (United States)

1990-01-01

The NASA SBIR Composite List of Projects, 1983 to 1989, includes all projects that have been selected for support by the Small Business Innovation Research (SBIR) Program of NASA. The list describes 1232 Phase 1 and 510 Phase 2 contracts that had been awarded or were in negotiation for award in August 1990. The main body is organized alphabetically by name of the small businesses. Four indexes cross-reference the list. The objective of this listing is to provide information about the SBIR program to anyone concerned with NASA research and development activities.

Composite fabrication via resin transfer molding technology

Energy Technology Data Exchange (ETDEWEB)

Jamison, G.M.; Domeier, L.A.

1996-04-01

The IMPReS (Integrated Modeling and Processing of Resin-based Structures) Program was funded in FY95 to consolidate, evaluate and enhance Sandia`s capabilities in the design and fabrication of composite structures. A key driver of this and related programs was the need for more agile product development processes and for model based design and fabrication tools across all of Sandia`s material technologies. A team of polymer, composite and modeling personnel was assembled to benchmark Sandia`s existing expertise in this area relative to industrial and academic programs and to initiate the tasks required to meet Sandia`s future needs. RTM (Resin Transfer Molding) was selected as the focus composite fabrication technology due to its versatility and growing use in industry. Modeling efforts focused on the prediction of composite mechanical properties and failure/damage mechanisms and also on the uncured resin flow processes typical of RTM. Appropriate molds and test composites were fabricated and model validation studies begun. This report summarizes and archives the modeling and fabrication studies carried out under IMPReS and evaluates the status of composite technology within Sandia. It should provide a complete and convenient baseline for future composite technology efforts within Sandia.

CREST : a computer program for the calculation of composition dependent self-shielded cross-sections

International Nuclear Information System (INIS)

Kapil, S.K.

1977-01-01

A computer program CREST for the calculation of the composition and temperature dependent self-shielded cross-sections using the shielding factor approach has been described. The code includes the editing and formation of the data library, calculation of the effective shielding factors and cross-sections, a fundamental mode calculation to generate the neutron spectrum for the system which is further used to calculate the effective elastic removal cross-sections. Studies to explore the sensitivity of reactor parameters to changes in group cross-sections can also be carried out by using the facility available in the code to temporarily change the desired constants. The final self-shielded and transport corrected group cross-sections can be dumped on cards or magnetic tape in a suitable form for their direct use in a transport or diffusion theory code for detailed reactor calculations. The program is written in FORTRAN and can be accommodated in a computer with 32 K work memory. The input preparation details, sample problem and the listing of the program are given. (author)

Fatigue of hybrid glass/carbon composites: 3D computational studies

DEFF Research Database (Denmark)

Dai, Gaoming; Mishnaevsky, Leon

2014-01-01

3D computational simulations of fatigue of hybrid carbon/glass fiber reinforced composites is carried out using X-FEM and multifiber unit cell models. A new software code for the automatic generation of unit cell multifiber models of composites with randomly misaligned fibers of various properties...... and geometrical parameters is developed. With the use of this program code and the X-FEM method, systematic investigations of the effect of microstructure of hybrid composites (fraction of carbon versus glass fibers, misalignment, and interface strength) and the loading conditions (tensile versus compression...... cyclic loading effects) on fatigue behavior of the materials are carried out. It was demonstrated that the higher fraction of carbon fibers in hybrid composites is beneficial for the fatigue lifetime of the composites under tension-tension cyclic loading, but might have negative effect on the lifetime...

The effects of a reformer Pilates program on body composition and morphological characteristics in active women after a detraining period.

Science.gov (United States)

Vaquero-Cristóbal, Raquel; Alacid, Fernando; Esparza-Ros, Francisco; López-Plaza, Daniel; Muyor, José M; López-Miñarro, Pedro A

2016-10-01

The aim of this quasi-experimental pilot study was to explore the effects of a reformer Pilates program on the anthropometry, body composition, and somatotype of active adult women after a short non-exercise period. Twenty-eight women (mean age: 40.21 ± standard deviation of 8.12 years old) with one to three years of reformer Pilates experience participated in the study. The women participated in a reformer Pilates program for 16 weeks (one hour, twice per week) after 4 weeks of detraining (summer holidays) in 2012. The International Society for the Advancement of Kinanthropometry full profile was assessed before and after the intervention program. Significant decreases (p ≤ 0.05) from pre- to post-program were observed for triceps, iliac crest, supraspinale, abdominal, front thigh and medial calf skinfold thicknesses, six and eight skinfold thickness sums, forearm and ankle girths, waist/hip ratio, endomorphy, and fat mass. Significant increases (p ≤ .05) were observed for corrected arm, corrected calf girths, and muscle mass. Generally, women showed a mesomorphic endomorph (endomorphy predominant) and mesomorph-endomorph (endomorphy and mesomorphy predominant) in the pre- and posttests, respectively. In conclusion, the practice of reformer Pilates was associated with healthy changes in anthropometric parameters, body composition, and somatotype in Pilates-experienced women after 4 weeks of no physical exercise.

Computer Program for Calculation of Complex Chemical Equilibrium Compositions and Applications II. Users Manual and Program Description. 2; Users Manual and Program Description

Science.gov (United States)

McBride, Bonnie J.; Gordon, Sanford

1996-01-01

This users manual is the second part of a two-part report describing the NASA Lewis CEA (Chemical Equilibrium with Applications) program. The program obtains chemical equilibrium compositions of complex mixtures with applications to several types of problems. The topics presented in this manual are: (1) details for preparing input data sets; (2) a description of output tables for various types of problems; (3) the overall modular organization of the program with information on how to make modifications; (4) a description of the function of each subroutine; (5) error messages and their significance; and (6) a number of examples that illustrate various types of problems handled by CEA and that cover many of the options available in both input and output. Seven appendixes give information on the thermodynamic and thermal transport data used in CEA; some information on common variables used in or generated by the equilibrium module; and output tables for 14 example problems. The CEA program was written in ANSI standard FORTRAN 77. CEA should work on any system with sufficient storage. There are about 6300 lines in the source code, which uses about 225 kilobytes of memory. The compiled program takes about 975 kilobytes.

Changes in body composition in heart failure patients after a resistance exercise program and branched chain amino acid supplementation.

Science.gov (United States)

Pineda-Juárez, Juan Antonio; Sánchez-Ortiz, Néstor Alonso; Castillo-Martínez, Lilia; Orea-Tejeda, Arturo; Cervantes-Gaytán, Rocío; Keirns-Davis, Candace; Pérez-Ocampo, Carlos; Quiroz-Bautista, Karla; Tenorio-Dupont, Mónica; Ronquillo-Martínez, Alberto

2016-02-01

Heart Failure (HF) is a complex syndrome, which can include the physiological, neural hormonal and metabolic complications known as "Cardiac Cachexia" (CC). In the development of CC there is a release of catabolic cytokines (Tumor Necrosis Factor-α, interleukins 1 and 6) that cause a decrease of fat free mass and fat mass. These changes in body composition might be reversed with a therapeutic combination of resistance exercise and branched chain amino acid supplementation (BCAA). Evaluate changes in body composition after a resistance exercise program and BCAA supplementation in patients with HF. In a randomized clinical trial with 3 month of follow-up anthropometric body composition analysis and stress tests were evaluated at the beginning and in the end of the study. Patients were divided into two groups; the experimental group performed the resistance exercise program and received 10 g/day BCAA supplementation, and the control group only performed the resistance exercise program. Both groups were provided with individualized diets and conventional medical treatment. Changes were found in hip circumference between the groups (p = 0.02), and muscle strength was increased in the experimental group (8%) and the control group (11.4%) with no difference between them. METS and VO2Max also increased in experimental and control groups (16.6% and 50.1% respectively). Regarding changes in symptoms, improvements in fatigue (45.4%), decubitus intolerance (21.8%) and dyspnea (25.4%) were observed in the overall sample. Improvements in physical and functional capacities are attributed to resistance exercise program but not to the BCAA supplementation. NCT02240511. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

The Lewis Chemical Equilibrium Program with parametric study capability

Science.gov (United States)

Sevigny, R.

1981-01-01

The program was developed to determine chemical equilibrium in complex systems. Using a free energy minimization technique, the program permits calculations such as: chemical equilibrium for assigned thermodynamic states; theoretical rocket performance for both equilibrium and frozen compositions during expansion; incident and reflected shock properties; and Chapman-Jouget detonation properties. It is shown that the same program can handle solid coal in an entrained flow coal gasification problem.

The Novel Attempt for Finding Minimum Solution in Fuzzy Neutrosophic Relational Geometric Programming (FNRGP with (max,min Composition

Directory of Open Access Journals (Sweden)

Huda E. Khalid

2016-08-01

Full Text Available This article sheds light on the possibility of finding the minimum solution set of neutrosophic relational geometric programming with (max, min composition. This work examines the privacy enjoyed by both neutrosophic logic and geometric programming, and how it affects the minimum solutions.

The impact of a 12-week resistance training program on strength, body composition, and self-concept of Hispanic adolescents.

Science.gov (United States)

Velez, Amelia; Golem, Devon L; Arent, Shawn M

2010-04-01

Current evidence suggests that a resistance training program may be physically and psychologically beneficial for adolescents. The purpose of this study was to examine the effects of a structured resistance training program on strength, body composition, and self-concept in normal and overweight Hispanic adolescents. Male and female participants (n = 28; 16.1 +/- 0.2 y; 164.5 +/- 1.4 cm; 63.3 +/- 2.5 kg; 20.0 +/- 1.7% body fat [BF]) were recruited from a predominantly Hispanic high school. Prior to the 12-week program, strength, body composition, and self-concept were assessed. Subjects were randomly assigned to a control group (CON; n = 15) or to a resistance training group (RT; n = 13) that participated in supervised strength training 3 days/week. All measures were repeated at the end of the 12-week program. RT had significantly greater strength increases for bench press (p increased %BF. RT had an increase in condition/stamina competence (p = 0.008), attractive body adequacy (p = 0.017), and global self-worth (p = 0.013) from pretest to posttest, whereas no change was observed for CON. In conclusion, resistance training resulted in significant physiological and psychological improvements in Hispanic adolescents compared to typical school-based activities. These findings indicate that resistance training can be incorporated into the activities of Hispanic adolescents to promote improved health and fitness.

The effect of programmed exercise on body compositions and heart rate of 11-13 years-old male students

Directory of Open Access Journals (Sweden)

Mohammad H. Dashti

2011-11-01

Full Text Available Background: Different forms of physical activities can play a very important role in improving health and physical fitness. The purpose of this study was to examine the effect of the programmed exercise on students’ body compositions and heart rate at rest.Materials and Method: Two groups each consisting of 15students, aged averagely 12.6 years were the subjects of this experimental study. The experimental group in each session took part in an exercise program consisting of 20 minutes of aerobic activity (running, 10 minutes of aerobic exercise, 30 minutes of local training and 5 minutes of free exercise. The experiment last for 24 sessions. Control group didn’t do any special practice. In both groups, weight, fat mass, fat percentage, lean body mass and heart rate were measured during rest period before and after the experiment. Results: Results showed that the fat percentage, weight, fat mass and heart rate had decreased after 8 weeks of programmed exercise in the experimental group unlike the control group. However, no significant difference was observed in lean body mass.Conclusion: The exercise program used in this study may help loosing weight and make the heart stronger

A composite-flywheel burst-containment study

Science.gov (United States)

Sapowith, A. D.; Handy, W. E.

1982-01-01

A key component impacting total flywheel energy storage system weight is the containment structure. This report addresses the factors that shape this structure and define its design criteria. In addition, containment weight estimates are made for the several composite flywheel designs of interest so that judgements can be made as to the relative weights of their containment structure. The requirements set down for this program were that all containment weight estimates be based on a 1 kWh burst. It should be noted that typical flywheel requirements for regenerative braking of small automobiles call for deliverable energies of 0.25 kWh. This leads to expected maximum burst energies of 0.5 kWh. The flywheels studied are those considered most likely to be carried further for operational design. These are: The pseudo isotropic disk flywheel, sometimes called the alpha ply; the SMC molded disk; either disk with a carbon ring; the subcircular rim with cruciform hub; and Avco's bi-directional circular weave disk.

MASBAL: A computer program for predicting the composition of nuclear waste glass produced by a slurry-fed ceramic melter

International Nuclear Information System (INIS)

Reimus, P.W.

1987-07-01

This report is a user's manual for the MASBAL computer program. MASBAL's objectives are to predict the composition of nuclear waste glass produced by a slurry-fed ceramic melter based on a knowledge of process conditions; to generate simulated data that can be used to estimate the uncertainty in the predicted glass composition as a function of process uncertainties; and to generate simulated data that can be used to provide a measure of the inherent variability in the glass composition as a function of the inherent variability in the feed composition. These three capabilities are important to nuclear waste glass producers because there are constraints on the range of compositions that can be processed in a ceramic melter and on the range of compositions that will be acceptable for disposal in a geologic repository. MASBAL was developed specifically to simulate the operation of the West Valley Component Test system, a commercial-scale ceramic melter system that will process high-level nuclear wastes currently stored in underground tanks at the site of the Western New York Nuclear Services Center (near West Valley, New York). The program is flexible enough, however, to simulate any slurry-fed ceramic melter system. 4 refs., 16 figs., 5 tabs

A Review Of Nutritional Guidelines And Menu Compositions For School Feeding Programs In 12 Countries.

Directory of Open Access Journals (Sweden)

Ruzky eAliyar

2015-08-01

Full Text Available Study objectives: To analyze the nutritional guidelines and menu compositions of school meal provision in various different countries.Background: School feeding is the provision of food on-site or to take home, which aims to increase school enrolment, attendance and retention, and exist as a social safety net for households with very low income. Home-grown school feeding (HGSF, additionally, aims to stimulate local economies by providing a source of income for local smallholder farmers. Methods: Literature searches using the Ovid MEDLINE databases, gathered information from in-country stakeholders, and accessed the programme websites of various countries. Nutrient composition of these menus was calculated from nutritional guidelines and menu compositions using a nutrition linear programming tool (NUTVAL.Country comparisons: School feeding aims differ between countries of each income group. The implementation, delivery of service and nutritional content of foods also differ considerably between countries and income groups. In high-income countries, guidelines and standards have been recommended in an attempt to combat rising levels of overweight and obesity, and to model healthier lifestyle habits. In low-income countries there is a gap in terms of guidance on nutrition standards and menu composition.Conclusions: Provision of evidence-based guidance on nutrition standards to middle and low income countries who have recently established or are planning to establish school feeding has the potential to greatly enhance and improve the quality of service and improve the life of millions of children worldwide.

Experimental and Numerical Study of FRP Encased Composite Concrete Columns

Directory of Open Access Journals (Sweden)

Mohsen Ishaghian

2017-02-01

Full Text Available A new type of composite column is presented and assessed through experimental testing and numerical modeling. The objective of this research is to investigate design options for a composite column without the use of ferrous materials. This is to avoid the current problem of deterioration of concrete due to expansion of rusting reinforcement members. Such a target can be achieved by replacing the steel reinforcement of concrete columns with pultruded I-shape glass FRP structural sections. The composite column utilizes a glass FRP tube that surrounds a pultruded I-section glass FRP, which is subsequently filled with concrete. The GFRP tube acts as a stay-in-place form in addition to providing confinement to the concrete. A total of four composite columns were tested under monotonic axial loading. The experimental ultimate capacity of each of the tested composite column was compared to the predicted numerical capacity using ANSYS program. The comparison showed that the predicted numerical values were in good agreement with the experimental ones.

Effects of a 2-Year Supervised Exercise Program Upon the Body Composition and Muscular Performance of HIV-Infected Patients

Science.gov (United States)

Paes, Lorena da Silva; Borges, Juliana Pereira; dos Santos, Fernanda Monteiro; de Oliveira, Taciana Pinto; Dupin, Jaciara Gomes; Harris, Elizabeth Assumpção; Farinatti, Paulo

2015-01-01

Background : There is a lack of research investigating long-term effects of exercise training upon the body composition and muscle function in HIV-infected patients (PHIV). The study investigated the influence of a 2-year supervised exercise program on body composition and strength of PHIV under highly active antiretroviral therapy (HAART). Methods : A training program including aerobic, strength and flexibility exercises was performed by 27 PHIV (17 men/ 10 women; age: 48.7±7.0 years; HAART: 150.7±65.3 months) during 1 year and 18 PHIV (10 men/ 8 women; age: 50.6±5.2 years; HAART: 176.6±53.1 months) during 2 years. Body composition and knee isokinetic strength were assessed at baseline and at the end of each year of intervention. Results : Body composition remained stable along the whole experiment vs baseline (1-year - total muscle mass: Δ men=1.1%, P=0.21; Δ women=1.4%, P=0.06; trunk fat: Δ men=-0.1%, P=0.65; Δ women=-1.5%, P=0.45; 2 years - total muscle mass: Δ men=2.7%, P=0.54; Δ women=-1.9%, P=0.71; trunk fat: Δ men=4.4%, P=0.96; Δ women=10.0%, P=0.30). After 1-year, peak torque increased in men (Δ extension=4.2%, P=0.01; Δ flexion=12.2%, P=0.04) and total work reduced in women (Δ extension=-15.4%, P=0.01, Δ flexion=-17.5%, P=0.05). All strength markers remained stable vs baseline after 2 years of intervention (P>0.05). Only men showed significant reduction in the risk of disability due to sarcopenia (P=0.05) after 1 year of intervention, which remained stable after 2 years. Conclusion : Long-term exercise training preserved strength and muscle mass in PHIV under HAART. Exercise programs should be part of HIV therapy to prevent sarcopenia of this population along the years. Trial Registration : ACTRN12610000683033; UTN U1111-1116-4416. PMID:26587076

An exploratory study of neuro linguistic programming and communication anxiety

Science.gov (United States)

Brunner, Lois M.

1993-12-01

This thesis is an exploratory study of Neuro-Linguistic Programming (NLP), and its capabilities to provide a technique or a composite technique that will reduce the anxiety associated with making an oral brief or presentation before a group, sometimes referred to as Communication Apprehension. The composite technique comes from NLP and Time Line Therapy, which is an extension to NLP. Student volunteers (17) from a Communications course given by the Administrative Sciences Department were taught this technique. For each volunteer, an informational oral presentation was made and videotaped before the training and another informational oral presentation made and videotaped following the training. The before and after training presentations for each individual volunteer were evaluated against criteria for communications anxiety and analyzed to determine if there was a noticeable reduction of anxiety after the training. Anxiety was reduced in all of the volunteers in this study.

Effects of a popular exercise and weight loss program on weight loss, body composition, energy expenditure and health in obese women

Directory of Open Access Journals (Sweden)

Magrans-Courtney Teresa

2009-05-01

Full Text Available Abstract Objective To determine the safety and efficacy of altering the ratio of carbohydrate and protein in low-energy diets in conjunction with a popular exercise program in obese women. Design Matched, prospective clinical intervention study to assess efficacy of varying ratios of carbohydrate and protein intake in conjunction with a regular exercise program. Participants One-hundred sixty one sedentary, obese, pre-menopausal women (38.5 ± 8.5 yrs, 164.2 ± 6.7 cm, 94.2 ± 18.8 kg, 34.9 ± 6.4 kg·m-2, 43.8 ± 4.2% participated in this study. Participants were weight stable and not participating in additional weight loss programs. Methods Participants were assigned to either a no exercise + no diet control (CON, a no diet + exercise group (ND, or one of four diet + exercise groups (presented as kcals; % carbohydrate: protein: fat: 1 a high energy, high carbohydrate, low protein diet (HED [2,600; 55:15:30%], 2 a very low carbohydrate, high protein diet (VLCHP [1,200 kcals; 63:7:30%], 3 a low carbohydrate, moderate protein diet (LCMP [1,200 kcals; 50:20:30%] and 4 a high carbohydrate, low protein diet (HCLP [1,200 kcals; 55:15:30%]. Participants in exercise groups (all but CON performed a pneumatic resistance-based, circuit training program under supervision three times per week. Measurements Anthropometric, body composition, resting energy expenditure (REE, fasting blood samples and muscular fitness assessments were examined at baseline and weeks 2, 10 and 14. Results All groups except CON experienced significant reductions (P P P P P Conclusion Exercise alone (ND appears to have minimal impact on measured outcomes with positive outcomes apparent when exercise is combined with a hypoenergetic diet. Greater improvements in waist circumference and body composition occurred when carbohydrate is replaced in the diet with protein. Weight loss in all diet groups (VLCHP, LCMP and HCLP was primarily fat and stimulated improvements in markers of

Interfaces study of all-polysaccharide composite films

Czech Academy of Sciences Publication Activity Database

Šimkovic, I.; Kelnar, Ivan; Mendichi, R.; Tracz, A.; Filip, J.; Bertók, T.; Kasák, P.

2018-01-01

Roč. 72, č. 3 (2018), s. 711-718 ISSN 0366-6352 Institutional support: RVO:61389013 Keywords : all-polysaccharide composites * elemental analysis * film properties study Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 1.258, year: 2016

Comparative Study of 3-Dimensional Woven Joint Architectures for Composite Spacecraft Structures

Science.gov (United States)

Jones, Justin S.; Polis, Daniel L.; Segal, Kenneth N.

2011-01-01

The National Aeronautics and Space Administration (NASA) Exploration Systems Mission Directorate initiated an Advanced Composite Technology (ACT) Project through the Exploration Technology Development Program in order to support the polymer composite needs for future heavy lift launch architectures. As an example, the large composite structural applications on Ares V inspired the evaluation of advanced joining technologies, specifically 3D woven composite joints, which could be applied to traditionally manufactured barrel segments. Implementation of these 3D woven joint technologies may offer enhancements in damage tolerance without sacrificing weight. However, baseline mechanical performance data is needed to properly analyze the joint stresses and subsequently design/down-select a preform architecture. Six different configurations were designed and prepared for this study; each consisting of a different combination of warp/fill fiber volume ratio and preform interlocking method (z-fiber, fully interlocked, or hybrid). Tensile testing was performed for this study with the enhancement of a dual camera Digital Image Correlation (DIC) system which provides the capability to measure full-field strains and three dimensional displacements of objects under load. As expected, the ratio of warp/fill fiber has a direct influence on strength and modulus, with higher values measured in the direction of higher fiber volume bias. When comparing the z-fiber weave to a fully interlocked weave with comparable fiber bias, the z-fiber weave demonstrated the best performance in two different comparisons. We report the measured tensile strengths and moduli for test coupons from the 6 different weave configurations under study.

Study of a classical strobe composition

NARCIS (Netherlands)

Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

2013-01-01

Many strobe compositions were discovered in the past but only a few have been studied and none of them were fully understood. This article aimed at introducing the ternary composition of ammonium perchlorate as oxidizer, magnalium as fuel, and barium sulfate as metal salt. Parameters that influence

Adolescent bariatric surgery program characteristics: the Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study experience.

Science.gov (United States)

Michalsky, Marc P; Inge, Thomas H; Teich, Steven; Eneli, Ihuoma; Miller, Rosemary; Brandt, Mary L; Helmrath, Michael; Harmon, Carroll M; Zeller, Meg H; Jenkins, Todd M; Courcoulas, Anita; Buncher, Ralph C

2014-02-01

The number of adolescents undergoing weight loss surgery (WLS) has increased in response to the increasing prevalence of severe childhood obesity. Adolescents undergoing WLS require unique support, which may differ from adult programs. The aim of this study was to describe institutional and programmatic characteristics of centers participating in Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS), a prospective study investigating safety and efficacy of adolescent WLS. Data were obtained from the Teen-LABS database, and site survey completed by Teen-LABS investigators. The survey queried (1) institutional characteristics, (2) multidisciplinary team composition, (3) clinical program characteristics, and (4) clinical research infrastructure. All centers had extensive multidisciplinary involvement in the assessment, pre-operative education, and post-operative management of adolescents undergoing WLS. Eligibility criteria and pre-operative clinical and diagnostic evaluations were similar between programs. All programs have well-developed clinical research infrastructure, use adolescent-specific educational resources, and maintain specialty equipment, including high weight capacity diagnostic imaging equipment. The composition of clinical team and institutional resources is consistent with current clinical practice guidelines. These characteristics, coupled with dedicated research staff, have facilitated enrollment of 242 participants into Teen-LABS. © 2013 Published by Elsevier Inc.

A 12-week rehabilitation program improves body composition, pain sensation, and internal/external torques of baseball pitchers with shoulder impingement symptom.

Science.gov (United States)

Cha, Jun-Youl; Kim, Jae-Hak; Hong, Ju; Choi, Young-Tae; Kim, Min-Ho; Cho, Ji-Hyun; Ko, Il-Gyu; Jee, Yong-Seok

2014-02-01

The aim of this study was to investigate the effects of a 12-week rehabilitation program on body composition, shoulder pain, and isokinetic internal/external torques of pitchers with impingement syndrome. A total of 30 pitchers were divided into 2 groups: experimental group (EG, n = 16) and control group (CG, n= 14). The rehabilitation program consisted of physical therapy, warm-up, work-out, and cool-down. As results, body weight and fat mass of EG were decreased whereas muscle mass of EG was significantly increased after the experiment. The pain degrees in resting, normal daily activity, and strenuous activity on the numeric pain rating scale were significantly decreased in the EG. The internal and external peak torques (PTs) of uninvolved and involved sides of EG were increased in EG after 12 weeks. Such results provide a deficit ratio of both sides in EG close to normal values. The ratios of internal/external PTs in EG were also close to the reference values. The internal and external total works of both sides in EG were similar to the values of PT. The fatigue indices of internal and external rotators of both sides in EG were decreased. As a conclusion, a 12-week rehabilitation program reduced the shoulder pain, improved the body composition and enhanced the isokinetic shoulder internal/external rotators in EG with impingement symptoms. Also the study suggested that the rehabilitation program evened out the ratio between internal and external rotators and lowered the fatigue level after the experiment.

An Analysis of Programming Beginners' Source Programs

Science.gov (United States)

Matsuyama, Chieko; Nakashima, Toyoshiro; Ishii, Naohiro

The production of animations was made the subject of a university programming course in order to make students understand the process of program creation, and so that students could tackle programming with interest. In this paper, the formats and composition of the programs which students produced were investigated. As a result, it was found that there were a lot of problems related to such matters as how to use indent, how to apply comments and functions etc. for the format and the composition of the source codes.

Compositional studies of primitive asteroids

International Nuclear Information System (INIS)

Vilas, F.

1988-01-01

The composition of primitive asteroids and their relationship to satellites in the solar system will be studied by analyzing existing narrowband charge coupled device (CCD) reflectance spectra, acquiring additional spectra of asteroids and small satellites in the 0.5 to 1.0 micrometer spectral range, and exploring possibilities for obtaining compositional information in the blue-UV spectral region. Comparison with laboratory spectra of terrestrial chlorites and serpentines (phyllosilicates) and the clay minerals found in carbonaceous chondrite meteorites will continue. During 1987, narrowband CCD reflectance spectra of 17 additional asteroids were acquired. These spectra and spectra of 34 other asteroids have been used primarily for two studies: weak absorption features similar to those due to Fe2(+) and Fe2(+) - Fe3(+) transitions in iron oxides f ound in terrestrial chlorites and serpentines and carbonaceous chondrites have been identified in some primitive asteroid spectra. There is a first indication that asteroids grouped by heliocentric distance show similar weak absorption features. Nonparametric statistics are being applied to test the hypothesis of discrete remnants of a gradation in composition of outer-belt asteroids

Comment to: The effects of an 8-week multicomponent inpatient treatment program on body composition and anaerobic fitness in overweight and obese children and adolescents

Directory of Open Access Journals (Sweden)

Radtke T

2014-03-01

Full Text Available Thomas Radtke,1 Bruno H Knöpfli,2 Johannes H Wildhaber,3 Jürg Hammer4 1Division of Cardiovascular Prevention, Rehabilitation and Sports Medicine, Swiss Cardiovascular Center, Inselspital, University Hospital and University of Bern, Bern, 2Kinder und Jugendmedizin, Zurich, 3Department of Pediatrics, Hospital Fribourg, Fribourg, 4Division of Intensive Care and Pulmonology, University Children's Hospital Basel, Basel, SwitzerlandWe note with surprise a recent paper entitled "The effects of an 8-week multicomponent inpatient treatment program on body composition and anaerobic fitness in overweight and obese children and adolescents" by Karner-Rezek et al1 published in the International Journal of General Medicine concerning the effects of an 8-week multicomponent inpatient treatment program on body composition and anaerobic fitness in overweight and obese children and adolescents. We would like to take this opportunity to comment on the study findings and, in particular, address the methodological inconsistencies and ambiguities in this study.View original paper by Karner-Rezek and colleagues.

NGNP Composites R&D Technical Issues Study

Energy Technology Data Exchange (ETDEWEB)

AREVA Federal Services

2008-09-01

This study identifies potential applications and design requirements for ceramic materials (CMs) and ceramic composite materials (CCMs) in the NGNP hightemperature gas-cooled reactor (HTGR) primary circuit. Components anticipated for fabrication from non-graphite CMs and CCMs are identified along with recommended normal and off-normal operating conditions. The evaluation defines required dimensions and material properties of the candidate materials for normal operating conditions (NOC), anticipated transients, abnormal events, and design basis events. The report also identifies additional activities required for codifying the selected materials. The activities include ASTM Standard and ASME Code development and other work to support NRC licensing of the plant. Evaluation of the NGNP baseline design indicates components requiring either CMs or CCMs depend upon the reactor operating temperatures. For a reactor outlet temperature of 900 oC, four of the five evaluated components would benefit from either CMs or CCMs. Although some thermal and mechanical data exist for most of the candidate materials, they all need additional irradiation, thermal, and mechanical testing. The codification process must take into account the type of material and the geometry of components using either CMs or CCMs. The process requires close integration of the design and the research and development (R&D) program, which has already started by using preliminary control rod component designs as the basis for establishing specimen geometry and test conditions. The remaining time and budget for completing the R&D program need further assessment.

Anthropometry and Body Composition of Preterm Neonates in the Light of Metabolic Programming.

Science.gov (United States)

Parlapani, Elisavet; Agakidis, Charalampos; Karagiozoglou-Lampoudi, Thomais

2018-01-01

The improved survival of preterm infants has led to increased interest regarding their health as adults. In the context of metabolic programming, the connection between perinatal and early postnatal nutrition and growth with health in later life has brought to the fore the role of catch-up growth during the first months of preterm infants' lives and its association with body fat and obesity in childhood or puberty. A state-of-the art review was conducted in order to assess the way catch-up is evaluated, in terms of timing and rate. Adequate growth is of major importance for neurodevelopment; however, it may compete with adiposity or metabolic health. Studies based on body composition assessment have given conflicting results as regards the effect of early versus late and rapid versus slow catch-up growth on later health, mainly attributed to the lack of established criteria and definitions. Given that adequate early nutrition is crucial for the neurodevelopment of preterm infants, further studies are needed on the role of catch-up growth in long-term outcome, using generally accepted qualitative and quantitative criteria.

Experimental investigation of defect criticality in FRP laminate composites

Science.gov (United States)

Joyce, Peter James

1999-11-01

This work examines the defect criticality of fiber reinforced polymer Composites. The objective is to determine the sensitivity of the finished composite to various process-induced defects. This work focuses on two different classes of process-induced defects; (1) fiber waviness in high performance carbon-fiber reinforced unidirectional composites and (2) void volume in low cost glass-fabric reinforced composites. The role of fiber waviness in the compressive response of unidirectional composites has been studied by a number of other investigators. Because of difficulties associated with producing real composites with varying levels of fiber waviness, most experimental studies of fiber waviness have evaluated composites with artificially induced fiber waviness. Furthermore, most experimental studies have been concentrated on the effects of out-of-plane fiber waviness. The objective of this work is to evaluate the effects of in-plane fiber waviness naturally occurring in autoclave consolidated thermoplastic laminates. The first phase of this project involved the development of a simple technique for measuring the resulting fiber waviness levels. An experimental investigation of the compression strength reduction in composites with in-plane fiber waviness followed. The experimental program included carbon-fiber reinforced thermoplastic composites manufactured from prepreg tape by hand layup, and carbon-fiber and glass-fiber reinforced composites manufactured from an experimental powder towpreg by filament winding and autoclave consolidation. The compression specimens exhibited kink band failure in the prepreg composite and varying amounts of longitudinal splitting and kink banding in the towpreg composites. The compression test results demonstrated the same trend as predicted by microbudding theory but the overall quantitative correlation was poor. The second thrust of this research evaluated void effects in resin transfer molded composites. Much of the existing

A social comparison theory analysis of group composition and efficacy of cancer support group programs.

Science.gov (United States)

Carmack Taylor, Cindy L; Kulik, James; Badr, Hoda; Smith, Murray; Basen-Engquist, Karen; Penedo, Frank; Gritz, Ellen R

2007-07-01

Group-based psychosocial programs provide an effective forum for improving mood and social support for cancer patients. Because some studies show more benefit for patients with initially high psychosocial distress, and little or no benefit for patients with initially low distress, support programs may better address patient needs by only including distressed patients. However, distressed patients may benefit particularly from the presence of nondistressed patients who model effective coping, an idea many researchers and extensions of social comparison theory support. We present a theoretical analysis, based on a social comparison perspective, of how group composition (heterogeneous group of distressed and nondistressed patients versus homogeneous group of distressed patients) may affect the efficacy of cancer support programs. We propose that a heterogeneous group allows distressed patients maximal opportunity for the various social comparison activities they are likely to prefer; a homogeneous group does not. Though the presence of nondistressed patients in a heterogeneous group potentially benefits distressed patients, the benefits for nondistressed patients are unclear. For nondistressed patients, heterogeneous groups may provide limited opportunities for preferred social comparison activity and may create the possibility for no benefit or even negative effects on quality of life. We also discuss ethical issues with enrolling nondistressed patients whose presence may help others, but whose likelihood of personal benefit is questionable.

Raters’ Perception and Expertise in Evaluating Second Language Compositions

Directory of Open Access Journals (Sweden)

Houman Bijani

2010-11-01

Full Text Available The consideration of rater training is very important in construct validation of a writing test because it is through training that raters are adapted to the use of students’ writing ability instead of their own criteria for assessing compositions (Charney, 1984. However, although training has been discussed in the literature of writing assessment, there is little research regarding raters’ perceptions and understandings of the training program. Although a few studies have looked at the differences between trained and untrained raters in writing assessment (Cumming, 1990; Huot, 1990, few studies have used a pre-and post-training design. The purpose of this study is to investigate the effectiveness of the training program on experienced and inexperienced raters with regard to a pre-and post- training design. Twelve EFL raters scored 45 pre-rated benchmark essay compositions by an authorized IELTS trainer. These essay compositions were scored before, during and after the training program. The results regarding the comparison across raters showed that inexperienced raters had wider range of inconsistency before training but they became more consistent than experienced raters after training.

A Generator for Composition Interpreters

DEFF Research Database (Denmark)

Steensgaard-Madsen, Jørgen

1997-01-01

programming language design, specification and implementation then apply. A component can be considered as defining objects or commands according to convenience. A description language including type information provides sufficient means to describe component interaction according to the underlying abstract......Composition of program components must be expressed in some language, and late composition can be achieved by an interpreter for the composition language. A suitable notion of component is obtained by identifying it with the semantics of a generalised structured command. Experiences from...

Study of Body Composition by Impedance Analysis

Science.gov (United States)

González-Solís, J. L.; Vargas-Luna, M.; Sosa-Aquino, M.; Bernal-Alvarado, J.; Gutiérrez-Juárez, G.; Huerta-Franco, R.; Sanchis-Sabater, A.

2002-08-01

This work presents a set of impedance measurements and preliminary results on the analysis of body composition using impedance spectroscopy. This study is made using a pork meat sample and spectra from fat and flesh region were independently obtained using the same electrodes array. From these measurements, and theoretical considerations, it is possible to explain the behavior of the composite sample flesh-fat-flesh and, fitting the electrical parameters of the model, it shows the plausibility of a physical and quantitative application to human corporal composition.

Transient behaviour study program of research reactors fuel elements at the Hydra Pulse Reactor

International Nuclear Information System (INIS)

Khvostionov, V.E.; Egorenkov, P.M.; Malankin, P.V.

2004-01-01

Program on behavior study of research reactor Fuel Elements (FE) under transient regimes initiated by excessive reactivity insertion is being presented. Program would be realized at HYDRA pulse reactor at Russian Research Center 'Kurchatov Institute' (RRC 'K1'). HYDRA uses aqueous solution of uranyl sulfate (UO 2 SO 4 ) as a fuel. Up to 30 MJ of energy can be released inside the core during the single pulse, effective power pulse width varying from 2 to 10 ms. Reactor facility allows to investigate behaviour of FE consisting of different types of fuel composition, being developed according to Russian RERTR. First part of program is aimed at transient behaviour studying of FE MR, IRT-3M, WWR-M5 types containing meats based on dioxide uranium in aluminum matrix. Mentioned FEs use 90% and 36% enriched uranium. (author)

[The effects of 16-weeks pilates mat program on anthropometric variables and body composition in active adult women after a short detraining period].

Science.gov (United States)

Vaquero-Cristóbal, Raquel; Alacid, Fernando; Esparza-Ros, Francisco; Muyor, José M; López-Miñarro, Pedro Ángel

2015-04-01

previous studies have analysed the effect of mat Pilates practice on anthropometric variables and body composition in sedentaries. To date no researchs have investigated the benefits of Pilates on these variables after a short detraining period. to determine the effect of a 16-week mat Pilates program on anthropometric variables, body composition and somatotype of women with previous practice experience after three weeks of detraining period. twenty-one women underwent a complete anthropometric assessment according with ISAK guidelines before and after a 16 week mat Pilates program (two days, one hour). All women had one to three years of mat Pilates experience and came to three weeks of detraining period (Christmas holiday). women showed significant decreases for body mass, BMI, upper limb (biceps and triceps) and trunk (subscapular, iliac crest, supraspinale and abdominal) individual skinfolds, 6 and 8 skinfold sums, endomorphy and fat mass; and a significant increases for muscle mass. The mean somatotype was classified as mesomorphic endomorph in the pre- (4.91, 4.01, 1.47) and post-test (4.68, 4.16, 1.69). Eight women changed their somatotype clasification after the intervention program. the practice of mat Pilates for 16 weeks caused changes associated with health state improvements on anthropometric variables, especially on skinfolds which significantly decreased, body composition (fat and muscle masses decreased and increased, respectively) and somatotype (there was a significantly decreased on the endomorph component in experienced women after three week of detraning. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Utilization of an Anti-Gravity Treadmill in a Physical Activity Program with Female Breast Cancer Survivors: A Pilot Study

Science.gov (United States)

FAIRMAN, CIARAN M.; KENDALL, KRISTINA L.; HARRIS, BRANDONN S.; CRANDALL, KENNETH J.; MCMILLAN, JIM

2016-01-01

Breast Cancer survivors can experience a myriad of physical and psychological benefits as a result of regular exercise. This study aimed to build on previous research using lower impact exercise programs by using an antigravity (Alter-G®) treadmill to administer cardiovascular training. The purpose of this study was to determine the effectiveness a physical activity program, including an Alter-G® treadmill, for improving physiological and psychosocial measures in female breast cancer survivors. A 14-week intervention using an AB-AB study design was employed. Six female breast cancer survivors were recruited to participate in the study. Participants attended three 60-minute sessions per week, consisting of a combination of muscular strength/endurance, and cardiovascular endurance exercises. Consistent with current literature and guidelines, exercise interventions were individualized and tailored to suit individuals. Data was collected and analyzed in 2013. Visual inspection of results found improvements in cardiovascular endurance and measures of body composition. Quality of life was maintained and in some cases, improved. Finally, no adverse effects were reported from the participants, and adherence to the program for those who completed the study was 97%. The results of this study suggest that the use of a physical activity program in combination with an Alter-G® treadmill may provide practical and meaningful improvements in measures of cardiovascular endurance and body composition. PMID:27293508

Advanced organic composite materials for aircraft structures: Future program

Science.gov (United States)

1987-01-01

Revolutionary advances in structural materials have been responsible for revolutionary changes in all fields of engineering. These advances have had and are still having a significant impact on aircraft design and performance. Composites are engineered materials. Their properties are tailored through the use of a mix or blend of different constituents to maximize selected properties of strength and/or stiffness at reduced weights. More than 20 years have passed since the potentials of filamentary composite materials were identified. During the 1970s much lower cost carbon filaments became a reality and gradually designers turned from boron to carbon composites. Despite progress in this field, filamentary composites still have significant unfulfilled potential for increasing aircraft productivity; the rendering of advanced organic composite materials into production aircraft structures was disappointingly slow. Why this is and research and technology development actions that will assist in accelerating the application of advanced organic composites to production aircraft is discussed.

Continuous Fiber Ceramic Composite (CFCC) Program: Gaseous Nitridation

Energy Technology Data Exchange (ETDEWEB)

R. Suplinskas G. DiBona; W. Grant

2001-10-29

Textron has developed a mature process for the fabrication of continuous fiber ceramic composite (CFCC) tubes for application in the aluminum processing and casting industry. The major milestones in this project are System Composition; Matrix Formulation; Preform Fabrication; Nitridation; Material Characterization; Component Evaluation

Change in weight and body composition in obese subjects following a hypocaloric diet plus different training programs or physical activity recommendations.

Science.gov (United States)

Benito, Pedro J; Bermejo, Laura M; Peinado, Ana B; López-Plaza, Bricia; Cupeiro, Rocío; Szendrei, Barbara; Calderón, Francisco J; Castro, Eliane A; Gómez-Candela, Carmen

2015-04-15

The aim of the present study was to compare the effects of different physical activity programs, in combination with a hypocaloric diet, on anthropometric variables and body composition in obese subjects. Ninety-six obese (men: n = 48; women: n = 48; age range: 18-50 yr) participated in a supervised 22-wk program. They were randomized into four groups: strength training (S; n = 24), endurance training (E; n = 26), combined strength + endurance training (SE; n = 24), and physical activity recommendations (C; n = 22). In addition, all groups followed the same hypocaloric diet. At baseline and at the end of the intervention, dietetic and physical activity variables were assessed using validated questionnaires. Anthropometric variables were recorded along with body composition variables measured using dual-energy X-ray absorptiometry techniques. At the end of the intervention, significant improvements were seen within groups in terms of body weight (S: -9.21 ± 0.83 kg; E: -10.55 ± 0.80 kg; SE: -9.88 ± 0.85 kg; C: -8.69 ± 0.89 kg), and total fat mass (S: -5.24 ± 0.55%; E: -5.35 ± 0.55%; SE: -4.85 ± 0.56%; C: -4.89 ± 0.59%). No differences were seen between groups at this time in terms of any other anthropometric or body composition variables examined. All groups increased their total physical activity in metabolic equivalents (MET) per week during the intervention, but with no difference between groups (S: 976 ± 367 MET-min/wk; E: 954 ± 355 MET-min/wk; SE: 1 329 ± 345 MET-min/wk; C: 763 ± 410 MET-min/wk). This study shows that, when combined with a hypocaloric diet, exercise training and adherence to physical activity recommendations are equally effective at reducing body weight and modifying body composition in the treatment of obesity (Clinical Trials Gov. number: NCT01116856). Copyright © 2015 the American Physiological Society.

Correction of heterogeneities in the issue compositions in the construction plans optimized in radiotherapy using linear programming

International Nuclear Information System (INIS)

Viana, Rodrigo Sartorelo S.; Lima, Ernesto A.B.F.; Florentino, Helenice de Oliveira; Fonseca, Paulo Roberto da; Homem, Thiago Pedro Donadon

2009-01-01

Linear programming models are widely found in the literature addressing various aspects involved in the creation of optimized planning for radiotherapy. However, most mathematical formulations does not incorporate certain factors that are of extreme importance for the formulation of a real planning like the attenuation of the beam of radiation and heterogeneity in the composition of tissue irradiated. In this context are proposed in this paper some modifications in the formulation of a linear programming problem with the objective of making the simulation closer to the real planning for radiotherapy and thus enable a more reliable and comprehensive planning requirements. (author)

A fishery-dependent based study of fish species composition and associated catch rates around oil and gas structures off Louisiana

International Nuclear Information System (INIS)

Stanley, D.R.; Wilson, C.A.

1990-01-01

The impact of oil and gas development on fish populations off Louisiana is presumed significant but poorly understood. This study was undertaken to determine the applicability of a logbook program in developing a long-term database of species composition and relative abundance of fish associated with oil and gas structures. A pilot logbook program involving 120 private vessel owners and 25 charterboat operators was conducted between March 1987 and December 1988. Participants recorded date, fishing time, fishing method, number of anglers, and catch composition at each structure fished. Logbooks from a total of 55 private vessel owners and 10 charterboat operators were used in the analysis. Data collected included 15,780 angler hours of fishing effort and 61,227 fish caught over the study period. A total of 1,719 trips were made to 589 different oil and gas structures with at least 46 different species of fish caught. Red snapper and spotted seatrout were the most commonly caught species and had the highest catch rates. Results differed from past logbook programs and creel surveys, possibly indicating a change in the community of fish associated with oil and gas structures

Ion beam studies. Part 5 - the computer simulation of composite ion implantation profiles

International Nuclear Information System (INIS)

Freeman, J.H.; Booker, D.V.

1977-01-01

The computer simulation of composite ion implantation profiles produced by continuous energy programming and by discrete multiple dose doping is described. It is shown that precise matching of the computed profile to various uniform and power-law distributions can be achieved. (author)

Nutritional composition of the commonly consumed composite dishes for the Barbados National Cancer Study.

Science.gov (United States)

Sharma, Sangita; Harris, Rachel; Cao, Xia; Hennis, Anselm J M; Leske, M Cristina; Wu, Suh-Yuh

2007-09-01

To provide, for the first time, the calculated nutritional composition of 32 composite dishes commonly consumed in Barbados to enable dietary intake to be calculated from a Quantitative Food Frequency Questionnaire developed specifically for this population to determine associations between diet and risk of prostate and breast cancer. Weighed recipes were collected in up to six different households for each of the 32 composite dishes. The average nutritional composition for these composite dishes was calculated using the US Department of Agriculture National Nutrient Database. One hundred and fifty-two weighed recipes were collected for 32 composite dishes: five were fish based, two were ground beef dishes, two were chicken based, two were offal based, two were lamb dishes, one was pork based, three were rice based, three were commonly consumed home-made drinks, and the remaining were miscellaneous items. A total of 152 weighed recipes were collected and we provide, for the first time, nutritional composition data for 32 commonly consumed food and drink items in Barbados. Such data are essential for assessing nutrient intake and determining associations between diet and prostate and breast cancer in the Barbados National Cancer Study.

Effects of a mini-trampoline rebounding exercise program on functional parameters, body composition and quality of life in overweight women.

Science.gov (United States)

Cugusi, Lucia; Manca, Andrea; Serpe, Roberto; Romita, Giovanni; Bergamin, Marco; Cadeddu, Christian; Solla, Paolo; Mercuro, Giuseppe

2018-03-01

Mini-trampoline rebounding exercise (MRE) is becoming a very popular form of fitness training. Despite awareness of this activity worldwide, a limited number of studies have systematically investigated the health effects correlated with MRE training. The aim of our study was to evaluate manifold health outcomes after 12 weeks of an MRE program in a group of overweight Italian women. Eighteen overweight women (age 38.05±10.5 years, BMI: 27.6±2.1 kg/m2) were enrolled in this study. Functional profile, strength, body composition, quality of life and pain intensity were assessed at baseline and after 12 weeks of MRE. Significant improvements were observed in the measurements of anthropometric profile and body composition (circumferences, fat mass, lean and muscular mass). Both a significant decrease in systolic and diastolic blood pressure values (from 128/80.5 to 123/71 mmHg, P<0.05) and an improvement in lipid and glucose profiles were observed. At maximal exercise testing, an increase in work capacity (from 104 to 123 watts, P=0.003) and VO2max (from 15.4 to 16.9 mL/kg/min, P=0.04) was found. SF-36 showed positive changes in four of the eight items as well as in the Mental Component Summary. With regard to the Brief Pain Inventory-SF, a decrease in both pain severity and the pain interference score was detected. MRE appears feasible to ensure positive effects on overall health and can be proposed to populations that could greatly benefit from training programs, such as overweight women.

Study on the Venus rock composition in the northern part of the Land Aphrodita at the Vega 2 landing spacecraft

International Nuclear Information System (INIS)

Surkov, Yu.A.; Moskaleva, L.P.; Shzheglov, O.P.; 9400005SU; AN SSSR, Moscow. Fizicheskij Inst.)

1986-01-01

A brief description is given of experiment on X-ray radiometric determination of the elemental composition of Venus rock carried out with the help of the landing spacecraft Vega 2. Preliminary data on the rock composition in the Northern part of the Land Aphrodita and geochemical interpretation of the studied rock character are given. The detailed analysis of the Venus rock composition with application of iterations according to the ITERA program (Surkov etalli 1983) and application of the data on content of natural raedioactive elements determined by the ''Vega-2'' station gamma spectrometer (Surkov and et alli). Show that in the northen part of the Land Aphrodita rock is close by its composition with rocks of anorthosite-norite-troctolite group, which are widely distributed on the Moon surface

Opportunities for in-depth compositional studies of comets: Summary from semester 2017A observations and prospects for a 2018 observing campaign

Science.gov (United States)

DiSanti, Michael A.; Dello Russo, Neil; Bonev, Boncho P.; Gibb, Erika L.; Roth, Nathan; Vervack, Ronald J.; McKay, Adam J.; Kawakita, Hideyo; Cochran, Anita L.

2017-10-01

The period from late 2016 to mid 2017 provided unusually rich observational opportunities for compositional studies of comets using ground-based IR and optical spectroscopy. Three ecliptic comets - Jupiter-family comet (JFC) 45P/Honda-Mrkos-Pajdusakova, JFC 41P/Tuttle-Giacobini-Kresak, and 2P/Encke - as well as two moderately bright nearly istotropic comets from the Oort cloud (C/2015 ER61 PanSTARRS and C/2015 V2 Johnson) experienced highly favorable appritions.In the IR, very long on-source integration times were accumulated on all targets, primarily with the powerful new high-resolution, cross-dispersed iSHELL spectrograph at the IRTF (Rayner et al. 2016 SPIE 9908:1) but also with NIRSPEC at Keck II. This enabled accurate production rates and abundance ratios for 8-10 native ices, and spatially resolved studies of coma physics (H2O rotational temperatures and column abundances). The recent availability of iSHELL coupled with the daytime observing capability at the IRTF has opened a powerful window for conducting detailed compositional studies of comets over a range of heliocentric distances (Rh), particularly at small Rh where studies are relatively sparse. Our campaign provided detections of (or stringent abundance limits for) hyper-volatiles CO and CH4, which are severely lacking in compositional studies of JFCs.For all of these targets, optical spectra measured photo-dissociation product species using the Tull Coude spectrograph at McDonald Observatory, and ARCES at Apache Point Observatory. When possible optical and IR observations were obtained contemporaneously, with the goal of addressing potential parent-product relationships.We summarize our campaign and highlight related presentations. Prospects for investigations during the upcoming favorable apparitions of JFCs 21P/Giacobini-Zinner and 46P/Wirtanen will also be discussed, along with increased capabilities for serial studies (i.e., measurements at multiple Rh) of newly discovered (Oort cloud) comets

How to use composite indicator and linear programming model for determine sustainable tourism.

Science.gov (United States)

Ziaabadi, Maryam; Malakootian, Mohammad; Zare Mehrjerdi, Mohammad Reza; Jalaee, Seied Abdolmajid; Mehrabi Boshrabadi, Hosein

2017-01-01

The tourism industry which is one of the most dynamic economic activities in today's world plays a significant role in the sustainable development. Therefore, in addition to paying attention to tourism, sustainable tourism must be taken into huge account; otherwise, the environment and its health will be damaged irreparably. To determine the level of sustainability in this study, indicators of sustainable tourism were first presented in three environmental health, economic and social aspects. Then, the levels of sustainable tourism and environmental sustainability were practically measured in different cities of Kerman Province using a composite indicator, a linear programming model, Delphi method and the questionnaire technique. Finally, the study cities (tourist attractions) were ranked. Result of this study showed that unfortunately the tourism opportunities were not used appropriately in these cities and tourist destinations, and that environmental aspect (health and environmental sustainability) had very bad situations compared to social and economic aspects. In other words, environmental health had the lowest levels of sustainability. The environment is a place for all human activities like tourism, social and economic issues; therefore, its stability and health is of great importance. Thus, it is necessary to pay more attention to sustainability of activities, management and environmental health in planning sustainable development in regional and national policy.

Aspect-Oriented Programming using Composition Filters

NARCIS (Netherlands)

Aksit, Mehmet; Tekinerdogan, B.

1998-01-01

Software engineers may experience problems in modeling certain aspects while applying object-oriented techniques [4, 10, 11]. Composition-Filters are capable of expressing various different kinds of aspects in a uniform manner. These aspects are, for example, inheritance and delegation [1] and

NGNP Composites R and D Technical Issues Study

International Nuclear Information System (INIS)

2008-01-01

This study identifies potential applications and design requirements for ceramic materials (CMs) and ceramic composite materials (CCMs) in the NGNP hightemperature gas-cooled reactor (HTGR) primary circuit. Components anticipated for fabrication from non-graphite CMs and CCMs are identified along with recommended normal and off-normal operating conditions. The evaluation defines required dimensions and material properties of the candidate materials for normal operating conditions (NOC), anticipated transients, abnormal events, and design basis events. The report also identifies additional activities required for codifying the selected materials. The activities include ASTM Standard and ASME Code development and other work to support NRC licensing of the plant. Evaluation of the NGNP baseline design indicates components requiring either CMs or CCMs depend upon the reactor operating temperatures. For a reactor outlet temperature of 900 oC, four of the five evaluated components would benefit from either CMs or CCMs. Although some thermal and mechanical data exist for most of the candidate materials, they all need additional irradiation, thermal, and mechanical testing. The codification process must take into account the type of material and the geometry of components using either CMs or CCMs. The process requires close integration of the design and the research and development (R and D) program, which has already started by using preliminary control rod component designs as the basis for establishing specimen geometry and test conditions. The remaining time and budget for completing the R and D program need further assessment.

Eimeria Oocyst Concentrations and Species Composition in Litter from Commercial Broiler Farms During Anticoccidial Drug or Live Eimeria Oocyst Vaccine Control Programs.

Science.gov (United States)

Jenkins, Mark C; Parker, Carolyn; Ritter, Donald

2017-06-01

The purpose of this study was to determine if Eimeria oocyst concentrations and species composition in commercial broiler house litter changed during different cycles of anticoccidial drug (ACD) or live Eimeria oocyst vaccine (VAC) control programs and if there was a correlation between Eimeria oocyst levels and broiler performance. Litter samples were collected from a total of 15 different broiler farms encompassing a total of 45 individual houses during at least one complete grow-out cycle over a 21-mo period. Of these 15 broiler farms, three were followed for the entire 21-mo period spanning three ACD and four VAC cycles. Samples were collected at 2, 4, and 7-8 wk of grow-out corresponding to starter, grower, and withdraw periods of the ACD cycle. On a number of occasions, litter samples were obtained just prior to chick placement. Eimeria oocysts were isolated from all samples, counted by microscopy, and extracted for DNA to identify Eimeria species by ITS1 PCR. In general, Eimeria oocyst concentration in litter reached peak levels at 2-4 wk of grow-out regardless of coccidiosis control measure being used. However, peak oocyst numbers were sometimes delayed until 7-8 wk, indicating some level of Eimeria spp. drug resistance or incomplete vaccine coverage. Eimeria maxima , Eimeria acervulina , Eimeria praecox, and Eimeria tenella were generally present in all samples, and no difference in the species composition was noted between houses on a particular farm. While Eimeria species composition was similar among houses, Eimeria spp. oocyst levels exhibited sporadic peaks in one house of a given location's houses. Of particular interest was the observed correlation between E. maxima oocyst abundance and chick mortality. However, no correlation was observed in E. maxima oocyst levels, and the performance parameters adjusted feed conversion ratio and average daily weight gain. This study showed that understanding the dynamics of Eimeria spp. oocyst levels and species

Development of a Lifespan-Based Novel Composite Person-Reported Outcome Measure Using Data from the CINRG Duchenne Natural History Study

Science.gov (United States)

2017-10-01

Duchenne natural history study PRINCIPAL INVESTIGATOR: McDonald, Craig M. CONTRACTING ORGANIZATION: University of California, Davis Davis, CA 95618...composite person- reported outcome measure using data from the CINRG Duchenne natural history study 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Craig...SUPPLEMENTARY NOTES 14. ABSTRACT Development of novel technologies and therapeutic agents to treat Duchenne muscular dystrophy (DMD) have increased

The Effect of a Comprehensive Lifestyle Modification Program on Glycemic Control and Body Composition in Patients with Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Ji-Soo Yoo, PhD, RN

2007-09-01

Conclusion: CLMP is a useful program, and its multiple approaches by nurses as the leaders and coordinators appear to have positive and synergistic roles in improving and maintaining stable glucose level and body composition in patients with type 2 diabetes.

Shape memory-based tunable resistivity of polymer composites

Energy Technology Data Exchange (ETDEWEB)

Luo, Hongsheng, E-mail: hongshengluo@163.com [Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Zhou, Xingdong; Ma, Yuanyuan [Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Yi, Guobin, E-mail: ygb116@163.com [Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Cheng, Xiaoling [Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Zhu, Yong [Shanghai Hiend Polyurethane Inc., No. 389, Jinshan District, Shanghai (China); Zu, Xihong; Zhang, Nanjun; Huang, Binghao; Yu, Lifang [Faculty of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China)

2016-02-15

Graphical abstract: Hybrid nanofillers of the CNTs and AgNPs were embedded into a shape memory polyurethane. The composites exhibited tunable conduction, which could be facially tailored by the compositions and the thermal–mechanical programming. - Highlights: • Electrically conductive polymer composites in bi-layer structure were fabricated. • The CNTs/AgNPs layer had influence on the mechanics and thermal transitions. • The conductivity could be facially tailored via a thermo-mechanical programming. • The AgNPs contents enlarged the gauge factor of the resistivity–strain curves. • Tunneling theory was suitable for simulating the strain-dependent behaviors. - Abstract: A conductive composite in bi-layer structure was fabricated by embedding hybrid nanofillers, namely carbon nanotubes (CNTs) and silver nanoparticles (AgNPs), into a shape memory polyurethane (SMPU). The CNT/AgNP-SMPU composites exhibited a novel tunable conductivity which could be facially tailored in wide range via the compositions or a specifically designed thermo-mechanical shape memory programming. The morphologies of the conductive fillers and the composites were investigated by scanning electron microscope (SEM). The mechanical and thermal measurements were performed by tensile tests and differential scanning calorimetry (DSC). By virtue of a specifically explored shape memory programming, the composites were stretched and fixed into different temporary states. The electrical resistivity (R{sub s}) varied accordingly, which was able to be stabilized along with the shape fixing. Theoretical prediction based upon the tunneling model was performed. The R{sub s}–strain curves of the composites with different compositions were well fitted. Furthermore, the relative resistivity and the Gauge factor along with the elongation were calculated. The influence of the compositions on the strain-dependent R{sub s} was disclosed. The findings provided a new avenue to tailor the conductivity

Twin study of genetic and environmental influences on adult body size, shape and composition

DEFF Research Database (Denmark)

Schousboe, K.; Visscher, P.M.; Erbas, B.

2004-01-01

), we determined zygosity by DNA similarity, and performed anthropometry and bioelectrical impedance analysis of body composition. The contribution to the total phenotypic variance of genetic, common environment, and individual environment was estimated in multivariate analysis using the FISHER program...... effects under the assumptions of no nonadditive effect. The pattern of age trends was inconsistent. However, when significant there was a decrease in heritability with advancing age. DISCUSSION: These findings suggest that adult body size, shape, and composition are highly heritable in both women and men...

The use of image analysis for the study of interfacial bonding in solid composite propellant

Directory of Open Access Journals (Sweden)

JASMINA DOSTANIC

2007-10-01

Full Text Available In the framework of this research, the program Image Pro Plus was applied for determining the polymer–oxidizer interactions in HTPB-based composite propellants. In order to improve the interactions, different bonding agents were used, and their efficiency was analyzed. The determination of the quantity, area and radius of non-bonded oxidizer crystals is presented. The position of formed cracks in the specimen and their area has a great influence on the mechanical properties of composite propellant. The preparation of the composite propellant in order to enable the photographing of their structure by means of stereoscopic and metallographic microscopes with the digital camera is also described as well.

Study of flax hybrid preforms reinforced epoxy composites

International Nuclear Information System (INIS)

Muralidhar, B. A

2013-01-01

Highlights: • We examine the thermal, viscoelastic and mechanical behaviour of flax preform hybrid composites. • The thermal stability of the matrix decrease with increasing volume fraction of flax preforms. • The effect of number of preform layers and the lay-up architecture were studied.. • Morphological study on the fractured surface of the composite laminate is carried out. - Abstracts: This study investigates the thermal, mechanical and thermomechanical properties of flax hybrid preform reinforced epoxy composites. Flax plain weave fabric and 1 × 1 weft rib knitted structures were together used as reinforcements and the composites were produced using hand lay-up technique. Specimen preparation and testing were carried out as per ASTM standards. Thermogravimetric analysis (TGA) indicates a decrease in thermal stability of the matrix polymer with the incorporation of flax hybrid preform. The dynamic mechanical analysis revealed a shift in the T g with the addition of flax hybrid preforms. Mechanical data obtained showed that tensile strength and stiffness is a product of the fibre/matrix synergy, whereas the compressive strength and stiffness are contributed by the reinforcing matrix. Additionally, investigation show that laminate with knitted preform as skin layer exhibits superior mechanical properties. However, improved tensile properties at lower fibre volume fraction, reinforces the opinion that hybrid preform composites can offer significant benefits in terms of performance, weight and overall cost. The failure mechanism was analysed, by scanning electron microscope (SEM)

Stochastic-Strength-Based Damage Simulation of Ceramic Matrix Composite Laminates

Science.gov (United States)

Nemeth, Noel N.; Mital, Subodh K.; Murthy, Pappu L. N.; Bednarcyk, Brett A.; Pineda, Evan J.; Bhatt, Ramakrishna T.; Arnold, Steven M.

2016-01-01

The Finite Element Analysis-Micromechanics Analysis Code/Ceramics Analysis and Reliability Evaluation of Structures (FEAMAC/CARES) program was used to characterize and predict the progressive damage response of silicon-carbide-fiber-reinforced reaction-bonded silicon nitride matrix (SiC/RBSN) composite laminate tensile specimens. Studied were unidirectional laminates [0] (sub 8), [10] (sub 8), [45] (sub 8), and [90] (sub 8); cross-ply laminates [0 (sub 2) divided by 90 (sub 2),]s; angled-ply laminates [plus 45 (sub 2) divided by -45 (sub 2), ]s; doubled-edge-notched [0] (sub 8), laminates; and central-hole laminates. Results correlated well with the experimental data. This work was performed as a validation and benchmarking exercise of the FEAMAC/CARES program. FEAMAC/CARES simulates stochastic-based discrete-event progressive damage of ceramic matrix composite and polymer matrix composite material structures. It couples three software programs: (1) the Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC), (2) the Ceramics Analysis and Reliability Evaluation of Structures Life Prediction Program (CARES/Life), and (3) the Abaqus finite element analysis program. MAC/GMC contributes multiscale modeling capabilities and micromechanics relations to determine stresses and deformations at the microscale of the composite material repeating-unit-cell (RUC). CARES/Life contributes statistical multiaxial failure criteria that can be applied to the individual brittle-material constituents of the RUC, and Abaqus is used to model the overall composite structure. For each FEAMAC/CARES simulation trial, the stochastic nature of brittle material strength results in random, discrete damage events that incrementally progress until ultimate structural failure.

Database for waste glass composition and properties

International Nuclear Information System (INIS)

Peters, R.D.; Chapman, C.C.; Mendel, J.E.; Williams, C.G.

1993-09-01

A database of waste glass composition and properties, called PNL Waste Glass Database, has been developed. The source of data is published literature and files from projects funded by the US Department of Energy. The glass data have been organized into categories and corresponding data files have been prepared. These categories are glass chemical composition, thermal properties, leaching data, waste composition, glass radionuclide composition and crystallinity data. The data files are compatible with commercial database software. Glass compositions are linked to properties across the various files using a unique glass code. Programs have been written in database software language to permit searches and retrievals of data. The database provides easy access to the vast quantities of glass compositions and properties that have been studied. It will be a tool for researchers and others investigating vitrification and glass waste forms

Study on Java Programming Education

OpenAIRE

太田, 信宏

2009-01-01

The purpose of this study is to consider the content and key points for inclusion in a Java programming course for beginners. The Java programming language has a variety of functions and has the largest application field of all such languages, containing many themes that are appropriate for any such programming course. The multifunctional and wide-ranging functions of Java, however, may actually act as a barrier to study for beginners. The core content of a programming class for beginners sho...

Boron carbide-carbon composites and composites for cryogenic applications

International Nuclear Information System (INIS)

Sheinberg, H.

1979-01-01

Because of its neutronic properties, high hardness, and high melting temperature, boron carbide (B 4 C) is widely used at the Los Alamos Scientific Laboratory. However because of its hardness and mode of manufacture, it is expensive to machine finish to tight dimensional specifictions. For some neutronic applications, a density considerably below the theoretical 2.52 Mg/m 3 was acceptable, and this relaxation in density specification permitted addition of carbon as a second phase to reduce machining costs. We conducted an experimental program to prepare 50.8-mm-diam by 34.8-mm-thick cylinders of B 4 C and B 4 C-C composites with concentrations of carbon varying from 5.5 to 30 volume percent. Additionally we used three forms of carbon, natural flake graphite, synthetic graphite flour, and a fine furnace black as the source of the second phase. We determined the sound velocity, compressive strength, coefficient of thermal expansion, electrical resistivity, and microstructure as functions of composition. Additionally, an enriched boron ( 10 B)-carbon composite was studied as an alternate material

Effect of Spinning Cycling Training on Body Composition in Women

Science.gov (United States)

Kaya, Fatih; Nar, Dilek; Erzeybek, Mustafa Said

2018-01-01

In this study the effects of a 6 week spinning cycling training on the body composition of women were investigated. Twelve sedentary women (32-47 years old) voluntarily participated in this study. The 6-week training program consisted of exercise sessions on 3 days per week. The intensity of the training program that was kept low in the beginning…

An experimental study on thermal properties of composite insulation

Energy Technology Data Exchange (ETDEWEB)

Choi, Gyoung-Seok [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea); Kang, Jae-Sik; Jeong, Young-Sun; Lee, Seung-Eon [Building and Urban Research Department, Korea Institute of Construction Technology, 2311 Daehwa-Dong, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea); Sohn, Jang-Yeul [College of Architecture, Hanyang University, 17, Hangdang-Dong, Sungdong-Gu, Seoul 133-791 (Korea)

2007-04-01

In accordance with the insulation standards reinforced since 2001 and the compulsory standards on floor impact sound insulation that have been enforced since 2004, insulation materials for actual buildings have been converted to composite materials and new insulation materials have been released in the market. However, Korea is lagging behind the world in fundamental experimental studies and resources. In case of some composite insulation materials, there also have been problems of distorted performance occurring as a result of tests being conducted without having verification and evaluation on the accuracy and inaccuracy of such tests. Therefore, this study grasped the thermal properties of composite insulation materials using thermal conductivity test equipment by heat flux method, and performed quantitative evaluation on the measurement precision and uncertainty of composite materials. (author)

Performance Study of the Natural Rubber Composite with Clay Minerals

International Nuclear Information System (INIS)

Nyo Nyo Myint; Tin Tin Aye; Kyaw Myo Naing; Nyunt Wynn

2008-03-01

The preparation, characterization and some applications of natural rubber clay composite have been studied. This study investigated the possibility of natural rubber latex to replace some part of natural clays. In formulation of rubber clay composite from natural rubber latex and various clay minerals, three main steps were involved (i) preparation of latex cream (ii) prevulcanization of latex cream (iii) mixing vulcanized latex compound, with other ingredients. In each step, several parameters have been carefully investigated to optimize the performance of natural rubber clay composite production. The composite products were of better quality and can be considered to be more cost effective.

International Research and Studies Program

Science.gov (United States)

Office of Postsecondary Education, US Department of Education, 2012

2012-01-01

The International Research and Studies Program supports surveys, studies, and instructional materials development to improve and strengthen instruction in modern foreign languages, area studies, and other international fields. The purpose of the program is to improve and strengthen instruction in modern foreign languages, area studies and other…

In vivo neutron activation analysis: body composition studies in health and disease

International Nuclear Information System (INIS)

Ellis, K.J.; Cohn, S.H.

1984-01-01

In vivo analysis of body elements by neutron activation is an important tool in medical research. It has provided a direct quantitative measure of body composition of human beings in vivo. Basic physiological differences related to age, sex, race, and body size have been assessed by this noninvasive technique. The diagnosis and management of patients with various metabolic disorders and diseases has also been demonstrated. Two major facilities at Brookhaven are being utilized exclusively for in vivo neutron activation analysis (IVNAA) of calcium, phosphorus, sodium, chlorine, nitrogen, hydrogen, and potassium. These elements serve as the basis for a four compartment model of body composition: protein, water, mineral ash, and fat. Variations in these compartments are demonstrated in clinical research programs investigating obesity, anorexia, cancer, renal failure, osteoporosis, and normal aging. IVNAA continues to provide a unique approach to the evaluation of clinical diagnosis, efficacy of therapeutic regimens, and monitoring of the aging process. Classical balance studies usually require the patient to be admitted to a hospital for extended periods of confinement. IVNAA, however, allows for clinical management of the patient on an out-patient basis, an important aspect for treatment of chronic diseases. 25 references, 3 figures, 5 tables

In vivo neutron activation analysis: body composition studies in health and disease

Energy Technology Data Exchange (ETDEWEB)

Ellis, K.J.; Cohn, S.H.

1984-01-01

In vivo analysis of body elements by neutron activation is an important tool in medical research. It has provided a direct quantitative measure of body composition of human beings in vivo. Basic physiological differences related to age, sex, race, and body size have been assessed by this noninvasive technique. The diagnosis and management of patients with various metabolic disorders and diseases has also been demonstrated. Two major facilities at Brookhaven are being utilized exclusively for in vivo neutron activation analysis (IVNAA) of calcium, phosphorus, sodium, chlorine, nitrogen, hydrogen, and potassium. These elements serve as the basis for a four compartment model of body composition: protein, water, mineral ash, and fat. Variations in these compartments are demonstrated in clinical research programs investigating obesity, anorexia, cancer, renal failure, osteoporosis, and normal aging. IVNAA continues to provide a unique approach to the evaluation of clinical diagnosis, efficacy of therapeutic regimens, and monitoring of the aging process. Classical balance studies usually require the patient to be admitted to a hospital for extended periods of confinement. IVNAA, however, allows for clinical management of the patient on an out-patient basis, an important aspect for treatment of chronic diseases. 25 references, 3 figures, 5 tables.

Study on thermal conductive BN/novolac resin composites

International Nuclear Information System (INIS)

Li, Shasha; Qi, Shuhua; Liu, Nailiang; Cao, Peng

2011-01-01

Highlights: → Boron nitride (BN) particles were used to modify novolac resin. → BN particles were pretreated by γ-aminopropyltriethoxysilane. → The thermal conductivity trend of composite almost agrees with the predicted data from the Maxwell-Eucken model. → At BN concentration of 80 wt.%, thermal conductivity value of composite is 4.5 times that of pure novolac resin. → Combined use of the larger and smaller particles with a mass ratio of 1:2 provides the composites with the maximum thermal conductivity among the testing systems. → The composite thermal property also increases with an increase in the BN concentration. - Abstract: In this study, γ-aminopropyltriethoxysilane-treated boron nitride (BN) particles were used to modify novolac resin. The effect of varying the BN concentration, particle size, and hybrid BN fillers with the binary particle size distribution on the thermal conductivity of the composites was investigated. Scanning electron microscopy (SEM) imaging showed homogeneously dispersed treated BN particles in the matrix. Furthermore, the thermal conductivity increased as the BN concentration was increased. This behavior was also observed when the filler size was increased. Experimentally obtained thermal conductivity values agree with the predicted data from the Maxwell-Eucken model well at less than 70 wt.% BN loading. A larger particle size BN-filled novolac resin exhibits a higher thermal conductivity than a smaller particle size BN-filled one. The combined use of 0.5 and 15 μm particles with a mass ratio of 2:1 achieved the maximum thermal conductivity among the testing systems. The thermal resistance properties of the composites were also studied.

Adjusting shape-memory properties of amorphous polyether urethanes and radio-opaque composites thereof by variation of physical parameters during programming

International Nuclear Information System (INIS)

Cui, J; Kratz, K; Lendlein, A

2010-01-01

Various composites have been prepared to improve the mechanical properties of shape-memory polymers (SMPs) or to incorporate new functionalities (e.g. magneto-sensitivity) in polymer matrices. In this paper, we systematically investigated the influence of the programming temperature T prog and the applied strain ε m as parameters of the shape-memory creation procedure (SMCP) on the shape-memory properties of an amorphous polyether urethane and radio-opaque composites thereof. Recovery under stress-free conditions was quantified by the shape recovery rate R r and the switching temperature T sw , while the maximum recovery stress σ max was determined at the characteristic temperature T σ,max under constant strain conditions. Excellent shape-memory properties were achieved in all experiments with R r values in between 80 and 98%. σ max could be tailored from 0.4 to 3.7 MPa. T sw and T σ,max could be systematically adjusted from 33 to 71 °C by variation of T prog for each investigated sample. The investigated radio-opaque shape-memory composites will form the material basis for mechanically active scaffolds, which could serve as an intelligent substitute for the extracellular matrix to study the influence of mechanical stimulation of tissue development

Feedback on composition: a case study of a remedial sixth-grader Feedback on composition: a case study of a remedial sixth-grader

Directory of Open Access Journals (Sweden)

Marilda C. Cavalcanti

2008-04-01

Full Text Available This paper reports on a case study conducted in Brazil, aimed at investigating the relationship between what a Portuguese native-language teacher provided as feedback on compositions in a remedial sixth-grade class and what the students thought about and did with that feedback. The study called for the teacher to fill out a questionnaire and to provide verbal report protocol data while making comments on the composition of a selected student. The student also provided a verbal report protocol concerning his reactions to the feedback, and all the students in the class filled out a questionnaire about their handling of the feedback. This paper reports on a case study conducted in Brazil, aimed at investigating the relationship between what a Portuguese native-language teacher provided as feedback on compositions in a remedial sixth-grade class and what the students thought about and did with that feedback. The study called for the teacher to fill out a questionnaire and to provide verbal report protocol data while making comments on the composition of a selected student. The student also provided a verbal report protocol concerning his reactions to the feedback, and all the students in the class filled out a questionnaire about their handling of the feedback.

Structural Acoustic Physics Based Modeling of Curved Composite Shells

Science.gov (United States)

2017-09-19

NUWC-NPT Technical Report 12,236 19 September 2017 Structural Acoustic Physics -Based Modeling of Curved Composite Shells Rachel E. Hesse...SUBTITLE Structural Acoustic Physics -Based Modeling of Curved Composite Shells 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...study was to use physics -based modeling (PBM) to investigate wave propagations through curved shells that are subjected to acoustic excitation. An

Computer Program for Calculation of Complex Chemical Equilibrium Compositions, Rocket Performance, Incident and Reflected Shocks, and Chapman-Jouguet Detonations. Interim Revision, March 1976

Science.gov (United States)

Gordon, S.; Mcbride, B. J.

1976-01-01

A detailed description of the equations and computer program for computations involving chemical equilibria in complex systems is given. A free-energy minimization technique is used. The program permits calculations such as (1) chemical equilibrium for assigned thermodynamic states (T,P), (H,P), (S,P), (T,V), (U,V), or (S,V), (2) theoretical rocket performance for both equilibrium and frozen compositions during expansion, (3) incident and reflected shock properties, and (4) Chapman-Jouguet detonation properties. The program considers condensed species as well as gaseous species.

Effects of a 5-month football program on perceived psychological status and body composition of overweight boys

DEFF Research Database (Denmark)

Seabra, A C; Seabra, A F; Brito, J

2014-01-01

The effects of a 5-month intervention of football instruction and practice on the perceived psychological status and body composition of overweight boys were examined. Twelve boys (8-12 years; body mass index ≥ 85th percentile) participated in a structured 5-month football program, consisting...... of four weekly 60-90 min sessions with mean heart rate > 80%HRmax [football group (FG)]. A control group (CG) included eight boys of equivalent age from an obesity clinic located in the same area as the school. Both groups participated in two sessions of 45-90-min physical education per week at school....... Indicators of perceived psychological status included body image, self-esteem, attraction to participation in physical activity, and perceived physical competence measured with standardized questionnaires. Body composition was evaluated using dual-energy X-ray absorptiometry. From baseline through 5 months...

Antibacterial Properties of Calcium Fluoride-Based Composite Materials: In Vitro Study

Science.gov (United States)

Zarzycka, Beata; Grzegorczyk, Janina; Sokołowski, Krzysztof; Półtorak, Konrad; Sokołowski, Jerzy

2016-01-01

The aim of the study was to evaluate antibacterial activity of composite materials modified with calcium fluoride against cariogenic bacteria S. mutans and L. acidophilus. One commercially available conventional light-curing composite material containing fluoride ions (F2) and two commercially available flowable light-curing composite materials (Flow Art and X-Flow) modified with 1.5, 2.5, and 5.0 wt% anhydrous calcium fluoride addition were used in the study. Composite material samples were incubated in 0.95% NaCl at 35°C for 3 days; then dilution series of S. mutans and L. acidophilus strains were made from the eluates. Bacteria dilutions were cultivated on media afterwards. Colony-forming unit per 1 mL of solution (CFU/mL) was calculated. Composite materials modified with calcium fluoride highly reduced (p composite materials containing fluoride compounds. The greatest reduction in bacteria growth was observed for composite materials modified with 1.5% wt. CaF2. All three tested composite materials showed statistically greater antibacterial activity against L. acidophilus than against S. mutans. PMID:28053976

Grinding, Machining Morphological Studies on C/SiC Composites

Science.gov (United States)

Xiao, Chun-fang; Han, Bing

2018-05-01

C/SiC composite is a typical material difficult to machine. It is hard and brittle. In machining, the cutting force is large, the material removal rate is low, the edge is prone to collapse, and the tool wear is serious. In this paper, the grinding of C/Si composites material along the direction of fiber distribution is studied respectively. The surface microstructure and mechanical properties of C/SiC composites processed by ultrasonic machining were evaluated. The change of surface quality with the change of processing parameters has also been studied. By comparing the performances of conventional grinding and ultrasonic grinding, the surface roughness and functional characteristics of the material can be improved by optimizing the processing parameters.

Bulk metallic glass matrix composite for good biocompatibility

International Nuclear Information System (INIS)

Hadjoub, F; Metiri, W; Doghmane, A; Hadjoub, Z

2012-01-01

Reinforcement volume fraction effects on acoustical parameters of Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 matrix composites reinforced by Mg, Ag and Cd metals have been studied via a simulation program based on acoustic microscopy technique. Moreover, acoustical parameters of human bone were compared to those of BMGs in both monolithic and reinforced case. It was found that elastic behavior of BMGs matrix composites in high reinforcement volume fraction is similar of that of human bone. This behavior leads to high biocompatibility and good transfer of stress between composite material and human system.

The effects of an 8-week multicomponent inpatient treatment program on body composition and anaerobic fitness in overweight and obese children and adolescents

Directory of Open Access Journals (Sweden)

Karner-Rezek K

2013-03-01

Full Text Available Klaus Karner-Rezek,1 Beat Knechtle,2,3 Matthias Fenzl,4 Christian Schlegel,4 Manuela Konrad,5 Thomas Rosemann2 1Private University of the Principality of Liechtenstein, Triesen, Principality of Liechtenstein, 2Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland; 3Gesundheitszentrum St Gallen, St Gallen, Switzerland; 4Swiss Olympic Medical Center, Medizinisches Zentrum Bad Ragaz, Switzerland; 5University of Applied Sciences JOANNEUM, Bad Gleichenberg, Austria Background: High intensity exercise is considered as an effective means for reducing body fat. The aims of the present study were to investigate (1 whether body mass would be lost and body composition would change and (2 whether variables of anaerobic fitness prior to the intervention period would be related to loss of body mass and changes in body composition in overweight and obese children and adolescents. Methods: A total of 28 children and adolescents (19 boys, 9 girls attended an 8-week multicomponent inpatient program. Caloric intake was based on the subject's weight and a daily energy deficit of ~500 kcal was targeted. At the beginning and at the end of the program, variables of anaerobic fitness were assessed using Wingate tests. Body composition was measured before and after the program using dual-energy X-ray absorptiometry. Results: Body mass decreased by 11.4% ± 1.6% in boys and by 11.0% ± 2.8% in girls (P < 0.001. Fat mass decreased by 23.8% ± 6.1% in boys and by 21.5% ± 5.2% in girls (P < 0.001. The decrease in fat mass was associated with the decrease in body mass in boys (r = 0.54, P = 0.017 but not in girls (P > 0.05. The decrease in body mass and the decrease in fat mass were neither associated with overall energy expenditure nor with the energy deficit in both genders (P > 0.05. Mean power in W/kg increased in the Wingate tests by 95.4% ± 109.1% in boys and by 100.0% ± 119.9% in girls (P < 0.001. Conclusions

Development of methods for body composition studies

International Nuclear Information System (INIS)

Mattsson, Soeren; Thomas, Brian J

2006-01-01

This review is focused on experimental methods for determination of the composition of the human body, its organs and tissues. It summarizes the development and current status of fat determinations from body density, total body water determinations through the dilution technique, whole and partial body potassium measurements for body cell mass estimates, in vivo neutron activation analysis for body protein measurements, dual-energy absorptiometry (DEXA), computed tomography (CT) and magnetic resonance imaging (MRI, fMRI) and spectroscopy (MRS) for body composition studies on tissue and organ levels, as well as single- and multiple-frequency bioimpedance (BIA) and anthropometry as simple easily available methods. Methods for trace element analysis in vivo are also described. Using this wide range of measurement methods, together with gradually improved body composition models, it is now possible to quantify a number of body components and follow their changes in health and disease. (review)

Development of methods for body composition studies

Energy Technology Data Exchange (ETDEWEB)

Mattsson, Soeren [Department of Radiation Physics, Lund University, Malmoe University Hospital, SE-205 02 Malmoe (Sweden); Thomas, Brian J [School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, QLD 4001 (Australia)

2006-07-07

This review is focused on experimental methods for determination of the composition of the human body, its organs and tissues. It summarizes the development and current status of fat determinations from body density, total body water determinations through the dilution technique, whole and partial body potassium measurements for body cell mass estimates, in vivo neutron activation analysis for body protein measurements, dual-energy absorptiometry (DEXA), computed tomography (CT) and magnetic resonance imaging (MRI, fMRI) and spectroscopy (MRS) for body composition studies on tissue and organ levels, as well as single- and multiple-frequency bioimpedance (BIA) and anthropometry as simple easily available methods. Methods for trace element analysis in vivo are also described. Using this wide range of measurement methods, together with gradually improved body composition models, it is now possible to quantify a number of body components and follow their changes in health and disease. (review)

Study of composite MWCNT/pyrolytic Cr interface by NEXAFS spectroscopy

International Nuclear Information System (INIS)

Petrova, O V; Nekipelov, S V; Mingaleva, A E; Sivkov, V N; Obiedkov, A M; Kaverin, B S; Kremlev, K V; Ketkov, S Yu; Gusev, S A; Vyalikh, D V; Molodtsov, S L

2016-01-01

A composite material based on MWCNT covered by pyrolytic Cr has been prepared by MOCVD growth technique using bis(arene)chromium compounds as the pyrolytic Cr source. Their structures and morphologies were preliminary studied by X-ray diffraction and scanning and scanning electron microscopy. The atomic and chemical composition of the interface, MWCNT surface and Cr-coating of the composite were studied by total electron yield mode in the range NEXAFS C1s - and Cr2p - absorption edge with use of synchrotron radiation of RGBL at BESSY-II. The study has shown that top layers of the MWCNT in composite have no essential destruction, the coating of the MWCNT surfaces is continuous and consists of Cr 2 O 3 . The chromium oxide adhesion is provided by chemical binding between the carbon atoms of the MWCNT top layer and the oxygen atoms of the coating. (paper)

Study on the electrical behavior of MWCNTs in GF/Epoxy composites.

Science.gov (United States)

Yan, Zhao; Lu, Yuan; Yuexin, Duan

2010-08-01

The multi-wall nanotubes (MWCNTs) were divisionalized equably by the fabric of glass in composites. Then the electrical properties such as permittivity, conductance and electromagnetic interference (EMI) shielding effectiveness (SE) of MWCNTs in GF/EP composite were studied. The effect of the content and dispersion of MWCNTs were researched in this work. Firstly the permittivity of MWCNTs/GF/EP composites were studied respectively by keeping layers of glass fabric and increasing content of MWCNTs or keeping content of MWCNTs and changing layers of glass fabric in electromagnetic wave band (5.85-18 GHz). Then the conductance of MWCNTs/GF/EP composites with different MWCNTs contents was tested. Furthermore, the EMI SE of composites with different MWCNTs contents in electromagnetic wave band (5.85-18 GHz) were studied. In addition, the morphologies of MWCNTs/GF/EP composites with the different MWCNTs weight percent were observed. The results show that the real part of permittivity of composites can be improved highest up to 75 and the imaginary part increase maximum up to 80. However there is no disciplinarian about effect of layers of glass fabric on dielectric property. The MWCNTs/GF/EP composite can be changed from the insulator to the semiconductor along with increasing the weight percent of MWCNTs. In electromagnetic wave band 5.85-18 GHz, the values of SE are increasing with increasing content of the MWCNTs.

Hybrid Composite Material and Solid Particle Erosion Studies

Science.gov (United States)

Chellaganesh, D.; Khan, M. Adam; Ashif, A. Mohamed; Ragul Selvan, T.; Nachiappan, S.; Winowlin Jappes, J. T.

2018-04-01

Composite is one of the predominant material for most challenging engineering components. Most of the components are in the place of automobile structure, aircraft structures, and wind turbine blade and so on. At the same all the components are indulged to mechanical loading. Recent research on composite material are machinability, wear, tear and corrosion studies. One of the major issue on recent research was solid particle air jet erosion. In this paper hybrid composite material with and without filler. The fibre are in the combination of hemp – kevlar (60:40 wt.%) as reinforcement using epoxy as a matrix. The natural material palm and coconut shell are used as filler materials in the form of crushed powder. The process parameter involved are air jet velocity, volume of erodent and angle of impingement. Experiment performed are in eight different combinations followed from 2k (k = 3) factorial design. From the investigation surface morphology was studied using electron microscope. Mass change with respect to time are used to calculate wear rate and the influence of the process parameters. While solid particle erosion the hard particle impregnates in soft matrix material. Influence of filler material has reduced the wear and compared to plain natural composite material.

Study of the AlON-VN composite ceramic

Energy Technology Data Exchange (ETDEWEB)

Sainbaatar; Zhang Zuotai; Li Wenchao; Wang Xidong [Dept. of Physical Chemistry of Metallurgy, Univ. of Science and Technology Beijing, BJ (China)

2005-07-01

Aluminium oxynitride-vanadium nitride (AlON-VN) composite ceramic was fabricated based on thermodynamic analysis of V-Al-O-N systems. The results indicated that the VN dispersed homogeneously in AlON matrix and can reinforce AlON matrix. Oxidation behavior was studied and the results showed that it belongs to self-protective oxidation due to the good adherence of oxidation product. Therefore, AlON-VN composites have excellent oxidation resistance. (orig.)

Studies on synthesis of some composites and their uses for cesium separation

International Nuclear Information System (INIS)

Someda, H.H.; El-Zahhar, A.A.; Shehata, M.K.K.; El-Naggar, H.A.

2002-01-01

In this study some composite sorbents were prepared by supporting hexacyanoferrate complexes of some transition metals like Co, Ni, Fe and Zn on some different solid supports e.g. cellulose and other natural materials as wood powder. These composites were used for cesium sorption and showed that the highest sorption capacity is for zinc composite and the lowest is for cobalt composite. Also the factors affecting the sorption capacity like acid concentration, competing ions and cesium ion concentration were studied. The release of the sorbed cesium from the composite materials was also studied under different concentrations of different solutions like sodium nitrate, silver nitrate, ammonium nitrate and a mixture of ammonium nitrate and silver nitrate solutions

Advanced Industrial Materials Program

Science.gov (United States)

Stooksbury, F.

1994-06-01

The mission of the Advanced Industrial Materials (AIM) program is to commercialize new/improved materials and materials processing methods that will improve energy efficiency, productivity, and competitiveness. Program investigators in the DOE national laboratories are working with about 100 companies, including 15 partners in CRDA's. Work is being done on intermetallic alloys, ceramic composites, metal composites, polymers, engineered porous materials, and surface modification. The program supports other efforts in the Office of Industrial Technologies to assist the energy-consuming process industries. The aim of the AIM program is to bring materials from basic research to industrial application to strengthen the competitive position of US industry and save energy.

Study of the dielectric properties of barium titanate-polymer composites

International Nuclear Information System (INIS)

Pant, H.C.; Patra, M.K.; Verma, Aditya; Vadera, S.R.; Kumar, N.

2006-01-01

A comparative study of complex dielectric properties has been carried out at the X-band of microwave frequencies of composites of barium titanate (BaTiO 3 ) with two different polymer matrices: insulating polyaniline (PANI) powder (emeraldine base) and maleic resin. From these studies, it is observed that the composites of BaTiO 3 with maleic resin show normal composite behavior and the dielectric constant follows the asymmetric Bruggeman model. In contrast, the composites of BaTiO 3 with PANI show an unusual behavior wherein even at a low concentration of PANI (5 wt.%) there is a drastic reduction in the dielectric constant of BaTiO 3 . This behavior of the dielectric constant is explained on the basis of coating of BaTiO 3 particles by PANI which in turn is attributed to the highly surface adsorbing character. The materials have also been characterized using Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and optical microscopy studies

EFFECTS OF PHYSICAL ACTIVITY ON BODY COMPOSITION IN ADULT WOMEN

Directory of Open Access Journals (Sweden)

Klára NAGY

2017-06-01

Full Text Available Data published by the World Health Organization (WHO and the International Association for the Study of Obesity (IASO suggests that the number of obese people in Europe has tripled in the last 20 years and resulted in a prevalence of 130 million obese and 400 million people overweight (Sassi et al., 2009.Body composition is the relative percentage of fat and fat-free mass (bones, muscles, organs, water, blood of total body weight. After Wilmore, Buskirk, DiGirolamo and Lohman (1986 the optimal level for health of body fat is 16-25% (18-30% for women.The objective of our study was to assess body composition of adult women, identifying the effect of intervention program on body fat and lean mass, and uncover cases of obesity and overweight.The study involved 95 adult women from Fit4U Fitness Center in Oradea. Period of the study: February 2015 -June 2016. Anthropometric measurements were made: height, weight, circumference, subcutaneous folds. It was calculated the body mass index (BMI, body composition and optimal body weight (estimation based on the five skinfolds measures. The physical activity program consisted of Step -aerobics, Pilates and strength training in the gym, 3 times a week for 60-90 minutes, for 12 months.Results:mean body mass, BMI, BF%, real BF decreased significantly. Mean body fat percentage from 25,63% (± 6,53 decreased to 22,95% (± 5,56. In the studied group overweight and obesity is more frequent in the age group between 35-44 years, but it can be seen the prevalence in all age groups.Conclusions:the physical activity program had a beneficial effect on body composition -by reducing body fat.We found cases of overweight and obesity (21% of the study group.

Metal matrix composites synthesis, wear characteristics, machinability study of MMC brake drum

CERN Document Server

Natarajan, Nanjappan; Davim, J Paulo

2015-01-01

This book is dedicated to composite materials, presenting different synthesis processes, composite properties and their machining behaviour. The book describes also the problems on manufacturing of metal matrix composite components. Among others, it provides procedures for manufacturing of metal matrix composites and case studies.

Study on Preparation and Property of Poly-Aminosilicone-Rare Earth Composite

Institute of Scientific and Technical Information of China (English)

Zhang Ming(张明); Qiu Guanming(邱关明); Chen Haiyan(陈海燕); Zhou Lanxiang(周兰香); Inoue Shinich; Okamoto Hiroshi

2003-01-01

The poly-aminosilicone-rare earth composite was prepared by poly-aminosilicone cross-linked with rare earth and active silanol. The thermal stability of the composites was studied by thermogravimetric analysis (TG). Force condition of the composites in electric field was analyzed and relative polarizability was derived. It is found that the composites containing different rare earth ions have different relative polarizability. The experiment results reveal that organosilicon materials with different electrical performance can be obtained by this way. Meanwhile, the absorption and flourescene spectrum of composites were also investigated. Compared to rare earth chloride, the spectrum properties of the composite are changed obviously. The possible reasons for these phenomena were discussed.

Removal of phenol from synthetic wastewater using carbon-mineral composite: Batch mechanisms and composition study

Science.gov (United States)

Kamaruddin, Mohamad Anuar; Alrozi, Rasyidah; Aziz, Hamidi Abdul; Han, Tan Yong; Yusoff, Mohd Suffian

2017-09-01

This study investigates the treatability of composite adsorbent made from waste materials and minerals which is widely available in Malaysia. The composite adsorbent was prepared based on wet attrition method which focuses on the determination of optimum dosage of each of raw materials amount by conventional design of experiment work. Zeolite, activated carbon, rice husk and limestone were ground to obtained particle size of 150 µm. 45.94% zeolite, 15.31% limestone, 4.38% activated carbon, 4.38% rice husk carbon and 30% of ordinary Portland cement (OPC). The mixture was mixed together under pre-determined mixing time. About 60% (by weight) of water was added and the mixture paste was allowed to harden for 24 hours and then submersed in water for three days for curing. Batch experimental study was performed on synthetic dissolving a known amount of solid crystal phenol with distilled water into the volumetric flasks. From the batch experimental study, it was revealed that the optimum shaking speed for removal of phenol was 200 rpm. The removal efficiency was 65%. The optimum shaking time for removing phenol was 60 minutes; the percentage achieved was 55%. The removal efficiency increased with the increased of the amount of composite adsorbent. The removal efficiency for optimum adsorbent dosage achieved 86%. Furthermore, the influence of pH solution was studied. The optimum pH for removing phenol was pH 6, with the removal percentage of 95%. The results implies that carbon-mineral based composite adsorbent is promising replacement for commercial adsorbent that provides alternative source for industrial adsorption application in various types of effluent treatment system.

Opinion: Composition Studies Saves the World!

Science.gov (United States)

Bizzell, Patricia

2009-01-01

Stanley Fish in his new book ["Save the World on Your Own Time" (New York: Oxford UP,2008)] says that composition studies presents "the clearest example" of what is desperately wrong in the academy, because in writing classrooms, he says, "more often than not anthologies of provocative readings take center stage and the actual teaching of writing…

Upper atmosphere research satellite program. [to study the chemistry energetics, and dynamics

Science.gov (United States)

Huntress, W. T., Jr.

1978-01-01

A satellite program to conduct research on the chemistry, energetics, and dynamics of the upper atmosphere was developed. The scientific goals of the Upper Atmospheric Research Program, the program requirements, and the approach toward meeting those requirements are outlined. An initial series of two overlapping spacecraft missions is described. Both spacecraft are launched and recovered by the STS, one in the winter of 1983 at a 56 deg inclination, and the other a year later at a 70 deg inclination. The duration of each mission is 18 months, and each carries instruments to make global measurements of the temperature, winds, composition, irradation, and radiance in the stratosphere, mesosphere, and lower thermosphere between the tropopause and 120 km altitude. The program requires a dedicated ground-based data system and a science team organization that leads to a strong interaction between the experiments and theory. The program includes supportive observations from other platforms such as rockets, balloons, and the Spacelab.

Multi-material Preforming of Structural Composites

Energy Technology Data Exchange (ETDEWEB)

Norris, Robert E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Eberle, Cliff C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pastore, Christopher M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sudbury, Thomas Z. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Xiong, Fue [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hartman, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-05-01

Fiber-reinforced composites offer significant weight reduction potential, with glass fiber composites already widely adopted. Carbon fiber composites deliver the greatest performance benefits, but their high cost has inhibited widespread adoption. This project demonstrates that hybrid carbon-glass solutions can realize most of the benefits of carbon fiber composites at much lower cost. ORNL and Owens Corning Reinforcements along with program participants at the ORISE collaborated to demonstrate methods for produce hybrid composites along with techniques to predict performance and economic tradeoffs. These predictions were then verified in testing coupons and more complex demonstration articles.

Composites for Exploration Upper Stage

Science.gov (United States)

Fikes, J. C.; Jackson, J. R.; Richardson, S. W.; Thomas, A. D.; Mann, T. O.; Miller, S. G.

2016-01-01

The Composites for Exploration Upper Stage (CEUS) was a 3-year, level III project within the Technology Demonstration Missions program of the NASA Space Technology Mission Directorate. Studies have shown that composites provide important programmatic enhancements, including reduced weight to increase capability and accelerated expansion of exploration and science mission objectives. The CEUS project was focused on technologies that best advanced innovation, infusion, and broad applications for the inclusion of composites on future large human-rated launch vehicles and spacecraft. The benefits included near- and far-term opportunities for infusion (NASA, industry/commercial, Department of Defense), demonstrated critical technologies and technically implementable evolvable innovations, and sustained Agency experience. The initial scope of the project was to advance technologies for large composite structures applicable to the Space Launch System (SLS) Exploration Upper Stage (EUS) by focusing on the affordability and technical performance of the EUS forward and aft skirts. The project was tasked to develop and demonstrate critical composite technologies with a focus on full-scale materials, design, manufacturing, and test using NASA in-house capabilities. This would have demonstrated a major advancement in confidence and matured the large-scale composite technology to a Technology Readiness Level 6. This project would, therefore, have bridged the gap for providing composite application to SLS upgrades, enabling future exploration missions.

Evaluation of the impact of a nutritional program for undernourished children in Brazil

NARCIS (Netherlands)

Santos, Iná S; Gigante, Denise P; Coitinho, Denise C; Haisma, Hinke; Valle, Neiva C J; Valente, Gicele

2005-01-01

To assess the effectiveness on child growth and body composition of a supplementary feeding program (Milk Supplement Program), a prospective, controlled study was conducted in Northeast Brazil. When entering the Program, children from 10 municipalities with the highest coverage rates in the Program

Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters

Science.gov (United States)

2009-12-01

ER D C TR -0 9- 10 Strategic Environmental Research and Development Program Phytoremediation of Composition-B Derived TNT and RDX in...Program ERDC TR-09-10 December 2009 Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters Elly P. H...for U.S. Army Corps of Engineers Washington, DC 20314-1000 ERDC TR-09-10 ii Abstract: This report describes a study in which phytoremediation of

Study on Physical Properties and Chemical Composition of Some Myanmar Gems

International Nuclear Information System (INIS)

Kyaw Myint Htoo; Tun Khin; Sein Htoon

2004-05-01

Physical properties of some Myanmar gems were studied by using refractometer, dichroscope, polariscope, SG test, UV test and microscope. Then, chemical composition were investigated by XRF-technique. After that, gem identification, evaluation, colour improvement were studied according to these physical properties and chemical composition

Study of the dielectric properties of barium titanate-polymer composites

Energy Technology Data Exchange (ETDEWEB)

Pant, H.C. [R and D Laboratory, Defence Laboratory, Camouflage Division, Defence Laboratory Ratanada Palace, Jodhpur 342011, Rajasthan (India); Patra, M.K. [R and D Laboratory, Defence Laboratory, Camouflage Division, Defence Laboratory Ratanada Palace, Jodhpur 342011, Rajasthan (India); Verma, Aditya [R and D Laboratory, Defence Laboratory, Camouflage Division, Defence Laboratory Ratanada Palace, Jodhpur 342011, Rajasthan (India); Vadera, S.R. [R and D Laboratory, Defence Laboratory, Camouflage Division, Defence Laboratory Ratanada Palace, Jodhpur 342011, Rajasthan (India); Kumar, N. [R and D Laboratory, Defence Laboratory, Camouflage Division, Defence Laboratory Ratanada Palace, Jodhpur 342011, Rajasthan (India)]. E-mail: nkjainjd@yahoo.com

2006-07-15

A comparative study of complex dielectric properties has been carried out at the X-band of microwave frequencies of composites of barium titanate (BaTiO{sub 3}) with two different polymer matrices: insulating polyaniline (PANI) powder (emeraldine base) and maleic resin. From these studies, it is observed that the composites of BaTiO{sub 3} with maleic resin show normal composite behavior and the dielectric constant follows the asymmetric Bruggeman model. In contrast, the composites of BaTiO{sub 3} with PANI show an unusual behavior wherein even at a low concentration of PANI (5 wt.%) there is a drastic reduction in the dielectric constant of BaTiO{sub 3}. This behavior of the dielectric constant is explained on the basis of coating of BaTiO{sub 3} particles by PANI which in turn is attributed to the highly surface adsorbing character. The materials have also been characterized using Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy and optical microscopy studies.

Effectiveness of a Medifast meal replacement program on weight, body composition and cardiometabolic risk factors in overweight and obese adults: a multicenter systematic retrospective chart review study.

Science.gov (United States)

Coleman, Christopher D; Kiel, Jessica R; Mitola, Andrea H; Langford, Janice S; Davis, Kevin N; Arterburn, Linda M

2015-08-06

Recent medical guidelines emphasize the importance of actively treating overweight and obesity with diet and lifestyle intervention to achieve ≥ 5% weight loss in a 6-month period. Commercial programs offer one approach provided there is evidence of their efficacy and safety. This study was conducted to evaluate the effectiveness of the Medifast® 4 & 2 & 1 Plan™ on weight loss, body composition and cardiometabolic risk factors in overweight and obese adults. A systematic retrospective chart review of 310 overweight and obese clients following the Medifast 4 & 2 & 1 Plan at one of 21 Medifast Weight Control Centers® was conducted. Data were recorded electronically and key data points were independently verified. The primary endpoint was change from baseline body weight at 12 weeks. Within group paired t-tests were used to examine changes from baseline in a completers population. Differences between gender and age subgroups were examined using bivariate t-tests and mixed model regression analyses. For the primary endpoint at 12 weeks, body weight among completers (n = 185) was reduced by a mean of 10.9 ± 5.6 kg (-10.1%, p meal plan was well tolerated, and program adherence was >85%. The 4 & 2 & 1 Plan used at Medifast Weight Control Centers was effective for weight loss, preservation of lean mass and improvement in cardiometabolic risk factors. The plan was generally well tolerated in a broad population of overweight and obese adults. #NCT02150837.

Studying impact damage on carbon-fiber reinforced aircraft composite panels with sonicir

International Nuclear Information System (INIS)

Han Xiaoyan; Zhang Ding; He Qi; Song Yuyang; Lubowicki, Anthony; Zhao Xinyue; Newaz, Golam.; Favro, Lawrence D.; Thomas, Robert L.

2011-01-01

Composites are becoming more important materials in commercial aircraft structures such as the fuselage and wings with the new B787 Dreamliner from Boeing which has the target to utilize 50% by weight of composite materials. Carbon-fiber reinforced composites are the material of choice in aircraft structures. This is due to their light weight and high strength (high strength-to-weight ratio), high specific stiffness, tailorability of properties, design flexibility etc. Especially, by reducing the aircraft's body weight by using such lighter structures, the cost of fuel can be greatly reduced with the high jet fuel price for commercial airlines. However, these composites are prone to impact damage and the damage may occur without any observable sign on the surface, yet resulting in delaminations and disbonds that may occur well within the layers. We are studying the impact problem with carbon-fiber reinforced composite panels and developing SonicIR for this application as a fast and wide-area NDE technology. In this paper, we present our results in studying composite structures including carbon-fiber reinforced composite materials, and preliminary quantitative studies on delamination type defect depth identification in the panels.

The effects of an exercise training program on body composition and aerobic capacity parameters in Tunisian obese children

Directory of Open Access Journals (Sweden)

Sofien Regaieg

2013-01-01

Full Text Available Background: The prevalence of children obesity is rising alarmingly in both developed and developing countries. Developing effective exercise programs is a strategy for decreasing this prevalence and limiting obesity-associated long-term comorbidities. Objectives: To determine whether a 16-week training program; in addition to the school physical education and without dietary intervention; could have beneficial effects on body composition and aerobic capacity of obese children. Materials and Methods: Twenty-eight obese children (16 boys, 12 girls; aged 12-14 years were enrolled and were divided into either the exercise group (EG, n = 14 or the control group (CG, n = 14. EG participated in a 16-week aerobic exercises (four 60-min sessions per week at 70-85% of HRmax (maximum heart rate, in addition to the school physical education. Fat-Free Mass (FFM and Fat Mass (FM were assessed with bioelectrical impedance equipment. To assess aerobic capacity, maximal metabolic equivalent of task (METmax and maximal workload (Wmax were estimated with an electronically braked cycle ergometer (type Ergoline 500® . Results: At baseline, there were no differences between the two groups. After the training program, only the EG showed significant reduction in BMI (body mass index and waist circumference compared with the baseline values (P < 0.001. Exercise training significantly decreased FM only in the EG. A significant increase in FFM was seen in both groups; more marked in the EG. There was a significant increase in METmax (P < 0.05 and Wmax (P = 0.02 in the EG, and no significant changes in these parameters were seen in the CG. HRmax significantly decreased only in the EG (P < 0.05. Conclusion: This training program has beneficial effects on body composition and aerobic capacity parameters in obese children. Our intervention has the advantage of providing a sustainable and reproducible school and community approach for the management of children obesity.

Studying the shielding properties of lead glass composites using neutrons and gamma rays

International Nuclear Information System (INIS)

Osman, A.M.; El-Sarraf, M.A.; Abdel-Monem, A.M.; El-Sayed Abdo, A.

2015-01-01

Highlights: • Samples of sodalime silica glass loaded with different ratios of PbO were prepared. • Leaded glass composites were investigated for radiation shielding. • Experimental and theoretical attenuation parameters were studied. • Experimental and theoretical (MCNP5) results were in good agreement. - Abstract: The present work deals with the shielding properties of lead glass composites to find out its integrity for practical shielding applications and radiological safety. Composites of different lead oxide ratios (x = 0, 5, 10, 15 and 25 wt.%) have been prepared by the Nasser Glass and Crystal Company (Egypt). Attenuation measurements have been carried out using a collimated emitted beam from a fission 252 Cf (100 μg) neutron source, and the neutron–gamma spectrometer with stilbene scintillator. The pulse shape discriminating (P.S.D.) technique based on the zero cross-over method was used to discriminate between neutron and gamma-ray pulses. Thermal neutron fluxes were measured using the BF3 detector and thermal neutron detection system. The attenuation relations were used to evaluate fast neutron macroscopic effective removal cross-section Σ R-Meas (cm −1 ), gamma rays total attenuation coefficient μ (cm −1 ) and thermal neutron macroscopic cross-section Σ Meas (cm −1 ). Theoretical calculations have been achieved using MCNP5 code to calculate the same two parameters. Also, MERCSF-N program was used to calculate fast neutron macroscopic removal cross-section Σ R-MER (cm −1 ). Measured and MCNP5 calculated results have been compared and were found to be in reasonable agreement

Surface topography of composite restorative materials following ultrasonic scaling and its Impact on bacterial plaque accumulation. An in-vitro SEM study.

Science.gov (United States)

Hossam, A Eid; Rafi, A Togoo; Ahmed, A Saleh; Sumanth, Phani Cr

2013-06-01

This is an in vitro study to investigate the effects of ultrasonic scaling on the surface roughness and quantitative bacterial count on four different types of commonly used composite restorative materials for class V cavities. Nanofilled, hybrid, silorane and flowable composites were tested. Forty extracted teeth served as specimen and were divided into 4 groups of 10 specimens, with each group receiving a different treatment and were examined by a Field emission scanning electron microscope. Bacterial suspension was then added to the pellicle-coated specimens, and then bacterial adhesion was analyzed by using image analyzing program. Flowable and silorane-based composites showed considerably smoother surfaces and lesser bacterial count in comparison to other types, proving that bacterial adhesion is directly proportional to surface roughness. The use of ultrasonic scalers affects the surfaces of composite restorative materials. Routine periodontal scaling should be carried out very carefully, and polishing of the scaled surfaces may overcome the alterations in roughness, thus preventing secondary caries, surface staining, plaque accumulation and subsequent periodontal inflammation. How to cite this article: Eid H A, Togoo R A, Saleh A A, Sumanth C R. Surface Topography of Composite Restorative Materials following Ultrasonic Scaling and its Impact on Bacterial Plaque Accumulation. An In-Vitro SEM Study. J Int Oral Health 2013; 5(3):13-19.

Study of detonation nanodiamond - plasma polymerized hexamethildisiloxan composites for medical application

International Nuclear Information System (INIS)

Pramatarova, L D; Krasteva, N A; Radeva, E I; Pecheva, E V; Dimitrova, R P; Hikov, T A; Mitev, D P; Hristova, K T; Altankov, G

2010-01-01

The present study reports on how detonation nanodiamond (DND) - plasma poly(hexamethyldisiloxane) composites (PPHMDS) affect osteoblast cell behavior. It has been established that various modified DND nanoparticles (Ag-DND and Si-DND) can be readily integrated into virtually all polymer matrices. In particular, PPHDMS composites have been developed over the past few years because of the variety of their application as medical devices and implants. By incubation of MG-63 osteoblast-like cells on the surface of DND (Ag-DND and Si-DND) - PPHMDS composite, we tested the hypothesis that DND-based polymer composites can influence the adhesion behavior of MG-63 osteoblast-like cells. Morphological and structural characterization of DND, Ag-DND and Si-DND powders was carried out by XRD, HRTEM and EDS. For the study of the composite layers, deposited on cover glass (CG), FTIR spectroscopy has been performed in order to determine if the DND nanofiller can potentially modify the structural and chemical dynamics of the polymer matrix. The kinetic of static water contact angle of composite surfaces as a function of the as-used nanofiller DND's in polymer matrix was measured The results with MG-63 osteoblast-like cells suggest the potential of using DND-based polymer composites for application in engineering implantable scaffolds and devices.

Study of detonation nanodiamond - plasma polymerized hexamethildisiloxan composites for medical application

Energy Technology Data Exchange (ETDEWEB)

Pramatarova, L D; Krasteva, N A; Radeva, E I; Pecheva, E V; Dimitrova, R P; Hikov, T A; Mitev, D P; Hristova, K T; Altankov, G, E-mail: lpramat@issp.bas.b

2010-11-01

The present study reports on how detonation nanodiamond (DND) - plasma poly(hexamethyldisiloxane) composites (PPHMDS) affect osteoblast cell behavior. It has been established that various modified DND nanoparticles (Ag-DND and Si-DND) can be readily integrated into virtually all polymer matrices. In particular, PPHDMS composites have been developed over the past few years because of the variety of their application as medical devices and implants. By incubation of MG-63 osteoblast-like cells on the surface of DND (Ag-DND and Si-DND) - PPHMDS composite, we tested the hypothesis that DND-based polymer composites can influence the adhesion behavior of MG-63 osteoblast-like cells. Morphological and structural characterization of DND, Ag-DND and Si-DND powders was carried out by XRD, HRTEM and EDS. For the study of the composite layers, deposited on cover glass (CG), FTIR spectroscopy has been performed in order to determine if the DND nanofiller can potentially modify the structural and chemical dynamics of the polymer matrix. The kinetic of static water contact angle of composite surfaces as a function of the as-used nanofiller DND's in polymer matrix was measured The results with MG-63 osteoblast-like cells suggest the potential of using DND-based polymer composites for application in engineering implantable scaffolds and devices.

Structural Behaviour of Strengthened Composite Materials. Experimental Studies

Directory of Open Access Journals (Sweden)

Vlad Munteanu

2007-01-01

Full Text Available Masonry represents one of the earliest structural materials used by mankind. A lot of the ancient building structures were made using masonry. A large number of these buildings have been stated historical monuments. Most commonly masonry elements which are able to cover large spans was masonry arches. The paper makes a detailed presentation on structural behaviour and failure mechanisms of a horizontally loaded masonry arch. The arch model was built at a 1 : 1 scale using solid bricks and M10Z mortar. It was firstly loaded with vertically acting dead loads and with horizontal load acting in its plane. In this loading hypothesis, a plastic hinge occurred leading to the failure of the arch and loss of load bearing capacity. In the next stage of the experimental program, the arch was strengthened using a composite material membrane at the upper face. The membrane consisted in a continuous, glass-fiber fabric and epoxy resin. After proper curing, the same loading hypothesis was used. The failure mechanisms changed and a larger horizontal loading level was noticed. Further on, the arch was rehabilitated using a different composite material layout, the membrane was applied both on upper and bottom faces as well as partially on the lateral faces of the arch. This new rehabilitation layout leads to a significant increase in the load bearing capacity of the arch. The failure mechanisms were changed causing a significantly better overall structural behaviour of the arch.

A Preliminary Study of Library Programs Related to American Indian Studies Programs in Colleges and Universities.

Science.gov (United States)

Townley, Charles

The presence of library programs and their relationship to academic programs of Native American Studies were surveyed in 27 institutions of higher education. Institutions surveyed were those with (1) a program for recruiting American Indians, (2) a distinct staff devoted to American Indians, and (3) some course about American Indians offered in a…

Writing Bodies: Somatic Mind in Composition Studies.

Science.gov (United States)

Fleckenstein, Kristie S.

1999-01-01

Discusses the somatic mind, a permeable materiality in which mind and body resolve into a single entity which is (re)formed by the constantly shifting boundaries of discursive and corporeal intertextualities. Addresses its importance in composition studies. Critiques the poststructuralist disregard of corporeality. (CR)

UCLA program in reactor studies: The ARIES tokamak reactor study

International Nuclear Information System (INIS)

1991-01-01

The ARIES research program is a multi-institutional effort to develop several visions of tokamak reactors with enhanced economic, safety, and environmental features. The aims are to determine the potential economics, safety, and environmental features of a range of possible tokamak reactors, and to identify physics and technology areas with the highest leverage for achieving the best tokamak reactor. Four ARIES visions are currently planned for the ARIES program. The ARIES-1 design is a DT-burning reactor based on ''modest'' extrapolations from the present tokamak physics database and relies on either existing technology or technology for which trends are already in place, often in programs outside fusion. ARIES-2 and ARIES-4 are DT-burning reactors which will employ potential advances in physics. The ARIES-2 and ARIES-4 designs employ the same plasma core but have two distinct fusion power core designs; ARIES-2 utilize the lithium as the coolant and breeder and vanadium alloys as the structural material while ARIES-4 utilizes helium is the coolant, solid tritium breeders, and SiC composite as the structural material. Lastly, the ARIES-3 is a conceptual D- 3 He reactor. During the period Dec. 1, 1990 to Nov. 31, 1991, most of the ARIES activity has been directed toward completing the technical work for the ARIES-3 design and documenting the results and findings. We have also completed the documentation for the ARIES-1 design and presented the results in various meetings and conferences. During the last quarter, we have initiated the scoping phase for ARIES-2 and ARIES-4 designs

Composites materials: the technology of future

International Nuclear Information System (INIS)

Ahmed, M.N.; Memon, I.R.; Ahmad, F.; Zafar, N.

2001-01-01

Composite materials have a long history of usage. Their precise beginnings are not known; however all recorded history contains references to some form of composite material. e.g. straw was used by man to strengthen mud bricks thousands of years ago. This article presents the use of advanced composites materials in aircraft and space industry. Its brief history, use in military and civil aviation, use in space program, future usage, advantages in terms of cost, weight and strength. Use of composites in unmanned aerial vehicles and problems associated with usage of composites materials are also discussed. (author)

Comparing routine neurorehabilitation program with trunk exercises based on Bobath concept in multiple sclerosis: pilot study.

Science.gov (United States)

Keser, Ilke; Kirdi, Nuray; Meric, Aydin; Kurne, Asli Tuncer; Karabudak, Rana

2013-01-01

This study compared trunk exercises based on the Bobath concept with routine neurorehabilitation approaches in multiple sclerosis (MS). Bobath and routine neurorehabilitation exercises groups were evaluated. MS cases were divided into two groups. Both groups joined a 3 d/wk rehabilitation program for 8 wk. The experimental group performed trunk exercises based on the Bobath concept, and the control group performed routine neurorehabilitation exercises. Additionally, both groups performed balance and coordination exercises. All patients were evaluated with the Trunk Impairment Scale (TIS), Berg Balance Scale (BBS), International Cooperative Ataxia Rating Scale (ICARS), and Multiple Sclerosis Functional Composite (MSFC) before and after the physiotherapy program. In group analysis, TIS, BBS, ICARS, and MSFC scores and strength of abdominal muscles were significantly different after treatment in both groups (p 0.05). Although trunk exercises based on the Bobath concept are rarely applied in MS rehabilitation, the results of this study show that they are as effective as routine neurorehabilitation exercises. Therefore, trunk exercises based on the Bobath concept can be beneficial in MS rehabilitation programs.

Standardization of the Food Composition Database Used in the Latin American Nutrition and Health Study (ELANS).

Science.gov (United States)

Kovalskys, Irina; Fisberg, Mauro; Gómez, Georgina; Rigotti, Attilio; Cortés, Lilia Yadira; Yépez, Martha Cecilia; Pareja, Rossina G; Herrera-Cuenca, Marianella; Zimberg, Ioná Z; Tucker, Katherine L; Koletzko, Berthold; Pratt, Michael

2015-09-16

Between-country comparisons of estimated dietary intake are particularly prone to error when different food composition tables are used. The objective of this study was to describe our procedures and rationale for the selection and adaptation of available food composition to a single database to enable cross-country nutritional intake comparisons. Latin American Study of Nutrition and Health (ELANS) is a multicenter cross-sectional study of representative samples from eight Latin American countries. A standard study protocol was designed to investigate dietary intake of 9000 participants enrolled. Two 24-h recalls using the Multiple Pass Method were applied among the individuals of all countries. Data from 24-h dietary recalls were entered into the Nutrition Data System for Research (NDS-R) program after a harmonization process between countries to include local foods and appropriately adapt the NDS-R database. A food matching standardized procedure involving nutritional equivalency of local food reported by the study participants with foods available in the NDS-R database was strictly conducted by each country. Standardization of food and nutrient assessments has the potential to minimize systematic and random errors in nutrient intake estimations in the ELANS project. This study is expected to result in a unique dataset for Latin America, enabling cross-country comparisons of energy, macro- and micro-nutrient intake within this region.

Standardization of the Food Composition Database Used in the Latin American Nutrition and Health Study (ELANS)

Science.gov (United States)

Kovalskys, Irina; Fisberg, Mauro; Gómez, Georgina; Rigotti, Attilio; Cortés, Lilia Yadira; Yépez, Martha Cecilia; Pareja, Rossina G.; Herrera-Cuenca, Marianella; Zimberg, Ioná Z.; Tucker, Katherine L.; Koletzko, Berthold; Pratt, Michael

2015-01-01

Between-country comparisons of estimated dietary intake are particularly prone to error when different food composition tables are used. The objective of this study was to describe our procedures and rationale for the selection and adaptation of available food composition to a single database to enable cross-country nutritional intake comparisons. Latin American Study of Nutrition and Health (ELANS) is a multicenter cross-sectional study of representative samples from eight Latin American countries. A standard study protocol was designed to investigate dietary intake of 9000 participants enrolled. Two 24-h recalls using the Multiple Pass Method were applied among the individuals of all countries. Data from 24-h dietary recalls were entered into the Nutrition Data System for Research (NDS-R) program after a harmonization process between countries to include local foods and appropriately adapt the NDS-R database. A food matching standardized procedure involving nutritional equivalency of local food reported by the study participants with foods available in the NDS-R database was strictly conducted by each country. Standardization of food and nutrient assessments has the potential to minimize systematic and random errors in nutrient intake estimations in the ELANS project. This study is expected to result in a unique dataset for Latin America, enabling cross-country comparisons of energy, macro- and micro-nutrient intake within this region. PMID:26389952

Standardization of the Food Composition Database Used in the Latin American Nutrition and Health Study (ELANS

Directory of Open Access Journals (Sweden)

Irina Kovalskys

2015-09-01

Full Text Available Between-country comparisons of estimated dietary intake are particularly prone to error when different food composition tables are used. The objective of this study was to describe our procedures and rationale for the selection and adaptation of available food composition to a single database to enable cross-country nutritional intake comparisons. Latin American Study of Nutrition and Health (ELANS is a multicenter cross-sectional study of representative samples from eight Latin American countries. A standard study protocol was designed to investigate dietary intake of 9000 participants enrolled. Two 24-h recalls using the Multiple Pass Method were applied among the individuals of all countries. Data from 24-h dietary recalls were entered into the Nutrition Data System for Research (NDS-R program after a harmonization process between countries to include local foods and appropriately adapt the NDS-R database. A food matching standardized procedure involving nutritional equivalency of local food reported by the study participants with foods available in the NDS-R database was strictly conducted by each country. Standardization of food and nutrient assessments has the potential to minimize systematic and random errors in nutrient intake estimations in the ELANS project. This study is expected to result in a unique dataset for Latin America, enabling cross-country comparisons of energy, macro- and micro-nutrient intake within this region.

Studies on structural properties of clay magnesium ferrite nano composite

Energy Technology Data Exchange (ETDEWEB)

Kaur, Manpreet, E-mail: manpreetchem@pau.edu; Singh, Mandeep [Department of Chemistry, Punjab Agricultural University, Ludhiana-141004 (India); Jeet, Kiran, E-mail: kiranjeet@pau.edu; Kaur, Rajdeep [Electron Microscopy and Nanoscience Laboratory, Punjab Agricultural University, Ludhiana-141004 (India)

2015-08-28

Magnesium ferrite-bentonite clay composite was prepared by sol-gel combustion method employing citric acid as complexing agent and fuel. The effect of clay on the structural properties was studied with X-ray diffraction (XRD), Fourier transform infrared (FT-IR) Spectroscopy, Scanning electron microscopy (SEM), SEM- Energy dispersive Spectroscope (EDS) and BET surface area analyzer. Decrease in particle size and density was observed on addition of bentonite clay. The BET surface area of nano composite containing just 5 percent clay was 74.86 m{sup 2}/g. Whereas porosity increased from 40.5 per cent for the pure magnesium ferrite to 81.0 percent in the composite showing that nano-composite has potential application as an adsorbent.

Improving body composition and strength in athletes through a 4-month combined martial arts and strength training program

Directory of Open Access Journals (Sweden)

Aleksandra Stachoń

2016-06-01

2Zakład Sportów Indywidualnych, Akademia Wychowania Fizycznego, ul. Paderewskiego 35, Wrocław       Corresponding author: Dr Aleksandra Jadwiga Stachoń, e-mail: aleksandra.stachon@awf.wroc.pl Departament of Physical Anthropology, University School of Physical Education in Wrocław, al. I.J. Paderewskiego 35, bud. P2, 51-612 Wrocław; Poland Phone: 71 347 33 44         Key words: resistance training, body build, body composition, combat sport.   Abstract Background and aim. Body composition is one of key components of health in both general and athletic populations. In martial arts great significance is attached to the development of mesomorphy and strength, which are crucial for performing offensive and defensive actions during fights. The study proposes to introduce progressive strength training programme - arranged primarily for beginners – in order to improve body composition of non-elite male martial arts competitors. The present study aims to evaluate the changes in body massiveness, body composition and strength in 31 martial arts practitioners from academic sports clubs after a combined martial arts and strength training programme. Material and methods. The 16-week intervention was based on a targeted progressive resistance training protocol developed by Stefaniak [1995]. The anthropometric, physical and motoric measurements were performed twice at four months interval. This programme includes training three times weekly with increased number of repetitions (19-24, number of sets (1-3 and increased loads (5%. Results. After the completion of the training program, significant increase for about 1.8 kgin body mass was observed. Body massiveness (BMI increased from 23.2 ± 1.8 kg/m2 to 23.9 ± 1.8 kg/m2. The analysis using Sheldon’s somatotypes revealed an increase of mesomorphy (from 5.5 to 5.7 and decrease of ectomorphy (from 2.5 to 2.4. The level of endomorphy became stable (2.1. The maximal circumferences of flexed arm, forearm, calf and

A continued program of planetary study at the University of Texas McDonald Observatory

Science.gov (United States)

Trafton, L.

1991-01-01

The program conducts solar system research in support of NASA missions and of general astronomical interest. Investigations of composition, physical characteristics and changes in solar system bodies are conducted primarily using the facilities of McDonald Observatory. Progress, accomplishments, and projected accomplishments are discussed.

Delamination tolerance studies in laminated composite panels

Indian Academy of Sciences (India)

Abstract. Determination of levels of tolerance in delaminated composite panels is an important issue in composite structures technology. The primary intention is to analyse delaminated composite panels and estimate Strain. Energy Release Rate (SERR) parameters at the delamination front to feed into acceptability criteria.

Penerapan Metode Profile Matching Pada Sistem Pendukung Keputusan Pemilihan Ketua Program Studi (STUDI Kasus : Program Studi Teknik Informatika STMIK Musi Rawas

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Andri Anto Tri Susilo

2018-01-01

Full Text Available Abstract-- In the organizational structure of a study program, always led by a chairman of the study program. In STMIK Musi Rawas, the process of selecting the head of the study program is usually appointed directly by the chairman of the foundation. The shortcomings of the direct appointment process is not able to see the capabilities possessed by the candidate chairman of the study program be it social skills, planning, management of learning, management of Human Resources, Finance and so forth. Decision support system is a system that can be used to help make decisions based on existing criteria. In this research the method used is Profile Matching method. The concept of Profile Matching method is to compare individual competence into job competence so that it can know the difference of competence (also called gap, the smaller the gap that is generated, the greater the value the greater the greater the chance for someone to occupy the position. The end result of this research is obtained information about the highest value of each candidate chairman of the Study Program based on the calculation of Profile Matching

Compositional data types

DEFF Research Database (Denmark)

Bahr, Patrick; Hvitved, Tom

2011-01-01

-cut fusion style deforestation which yields considerable speedups. We demonstrate our framework in the setting of compiler construction, and moreover, we compare compositional data types with generic programming techniques and show that both are comparable in run-time performance and expressivity while our...

Building Face Composites Can Harm Lineup Identification Performance

Science.gov (United States)

Wells, Gary L.; Charman, Steve D.; Olson, Elizabeth A.

2005-01-01

Face composite programs permit eyewitnesses to build likenesses of target faces by selecting facial features and combining them into an intact face. Research has shown that these composites are generally poor likenesses of the target face. Two experiments tested the proposition that this composite-building process could harm the builder's memory…

1-3 Composites Study

National Research Council Canada - National Science Library

Gabrielson, Thomas B

2003-01-01

...) In a transducer in which the active material is sandwiched between mass elements, the filler in a 1-3 composite degrades performance with respect to an unfilled array of piezoelectric rods. (3...

Development of environmental consequence index (ECI) using fuzzy composite programming

International Nuclear Information System (INIS)

Arunraj, N.S.; Maiti, J.

2009-01-01

Estimation of environmental consequences of hazardous substances in chemical industries is a very difficult task owing to (i) diversity in the types of hazards and their effects, (ii) location, and (ii) uncertainty in input information. Several indices have been developed over the years to estimate the environmental consequences. In this paper, a critical literature review was done on the existing environmental indices to identify their applications and limitations. The existing indices lack in consideration of all environmental consequence factors such as material hazard factors, dispersion factors, environmental effects, and their uncertainty. A new methodology is proposed for the development of environmental consequence index (ECI), which can overcome the stated limitations. Moreover, the recently developed fuzzy composite programming (FCP) is used to take care of the uncertainty in estimation. ECI is applied to benzene extraction unit (BEU) of a petrochemical industry situated in eastern part of India. The ECI for all the eight sections of BEU are estimated and ranked. The results are compared with well-established indices such as Dow fire and explosion index, safety weight hazard index (SWeHI), and environmental accident index (EAI). The proposed ECI may outperform other indices based on its detailed consideration of the factors and performed equally to Dow F and E index, and EAI in most of the cases for the present application

Embracing Wicked Problems: The Turn to Design in Composition Studies

Science.gov (United States)

Marback, Richard

2009-01-01

Recent appeal to the concept of design in composition studies benefits teaching writing in digital media. Yet the concept of design has not been developed enough to fully benefit composition instruction. This article develops an understanding of design as a matter of resolving wicked problems and makes a case for the advantages of this…

Focus: Composition and Language Study, K-6.

Science.gov (United States)

Stewart, Donald, Ed.

1974-01-01

This issue of "Kansas English" focus on composition and language study, kindergarten through grade six. The articles and authors are "Evaluating Process and Product in Children's Writing" by Robert L. Hillerich, "Written Language Development and Instruction of Elementary School Children" by Lester S. Golub, "From a Reading Desk" by Myrline…

Nanobioceramic Composites: A Study of Mechanical, Morphological, and Thermal Properties

Directory of Open Access Journals (Sweden)

Sivabalan Sasthiryar

2013-12-01

Full Text Available The aim of this study was to explore the incorporation of biomass carbon nanofillers (CNF into advanced ceramic. Biomass from bamboo, bagasse (remains of sugarcane after pressing, and oil palm ash was used as the predecessor for producing carbon black nanofillers. Furnace pyrolysis was carried out at 1000 °C and was followed by ball-mill processing to obtain carbon nanofillers in the range of 50 nm to 100 nm. CNFs were added to alumina in varying weight fractions and the resulting mixture was subjected to vacuum sintering at 1400 °C to produce nanobioceramic composites. The ceramic composites were characterized for mechanical, thermal, and morphological properties. A high-resolution Charge-coupled device (CCD camera was used to study the fracture impact and the failure mechanism. An increase in the loading percentage of CNFs in the alumna decreased the specific gravity, vickers hardness (HV, and fracture toughness values of the composite materials. Furthermore, the thermal conductivity and the thermal stability of the ceramic composite increased as compared to the pristine alumina.

Aspect oriented service composition for telecommunication applications

NARCIS (Netherlands)

Niemöller, Jörg

2016-01-01

This PhD dissertation investigates how to overcome the negative effects of cross cutting concerns in the development of composite service applications. It proposes a combination of dynamic aspect oriented programming with a rules driven service composition mechanism. This combination allows very

Study on influence of vibration behavior of composite material damage by holography

Science.gov (United States)

Guo, Linfeng; Zhao, Zhimin; Gao, Mingjuan; Zhuang, Xianzhong

2006-01-01

Composite material has been applied widely in aeronautics, astronautics and some other fields due to their high strength, light weight and antifatigue and etc. But in the application, composite material may be destroyed or damaged, which may have impact on its further applications. Therefore, study on the influence of behavior of composite material damage becomes a hot research. In this paper, the common composite material for aircraft is used as the test object, and a study is conducted to investigate the influence of vibration behavior of composite material damage. The authors adopt the method of light-carrier wave and time-average holography. Compared the interference fringes of composite materials before and after damage, the width of the interference fringes of hologram of the damaged composite material is narrower than that of the fringes before. It means that the off-plane displacement of each point on the test object is larger than before. Based on the elastic mechanics theory, the off-plane displacement is inverse to the bending stiffness, and the bending stiffness of the test object will decrease after it is damaged. In other words, the vibration property of the composite material changes after damages occur. The research results of the paper show that the results accord with the analysis of theory.

The NordiNet® International Outcome Study and NovoNet® ANSWER Program®

DEFF Research Database (Denmark)

Höybye, Charlotte; Sävendahl, Lars; Christesen, Henrik Thybo

2013-01-01

on the safety and effectiveness of reallife treatment with the recombinant human GH, Norditropin®. We describe the origins, aims, objectives, and design methodology of the studies, as well as their governance and validity, strengths, and limitations. CONCLUSION: The NordiNet® IOS and ANSWER Program® studies...... will provide valid insights into the effectiveness and safety of GH treatment across a diverse and large patient population treated in accordance with real-world clinical practice and following the Good Pharmacoepidemiological Practice and STrengthening the Reporting of OBservational studies in Epidemiology......OBJECTIVE: Randomized controlled trials have shown that growth hormone (GH) therapy has effects on growth, metabolism, and body composition. GH therapy is prescribed for children with growth failure and adults with GH deficiency. Carefully conducted observational study of GH treatment affords...

Study of Selected Composites Copper Concentrate-Plastic Waste Using Thermal Analysis

Science.gov (United States)

Szyszka, Danuta

2017-12-01

The paper presents thermal analysis of selected composites (copper concentrate, plastic waste) in two stages. The first stage consisted in thermogravimetric analysis and differential thermal analysis on the applied plastic waste and copper concentrate, and subsequently, a comparative study has been carried out on products obtained, constituting composites of those materials. As a result of analyses, it was found that up to ca. 400 °C composites show high thermal stability, whereas above that temperature, a thermal decomposition of the composite occurs, resulting in emissions of organic compounds, i.e. hydrocarbon compounds and organic oxygenate derivatives.

ANALISIS KESIAPAN PROGRAM STUDI DALAM PRODUCTION BASED EDUCATION: STUDI PADA PROGRAM STUDI D3 AKUNTANSI POLINES

Directory of Open Access Journals (Sweden)

Muhammad Noor Ardiansah

2015-03-01

Full Text Available There has been no clear studies to identify, verify and analyze readiness program resources in order to study the implementation of PBE resulted in initial position (existing point is not clear that the priority programs and activities that are carried out per year tend to be responsive and not directed priorities. These conditions resulted in analysis of resource readiness courses in the management of production-based learning pattern PBE draw conducted This study aims to identify and verify and analyze readiness resources management courses in the pattern of production based learning, particularly in the Accounting Studies Program. This research is expected to be used to increase the effectiveness of learning and vocational education to improve the quality and relevance of polytechnic graduates. Total score was 33 the existence of resources from the scale of 12-60. The average score is 2.75. The average score was shown the position of Prodi's resources have been used, but its role is unclear (repeatable tend to have clearly defined functions, communicated and documented (defined. Resources have been managed, monitored and evaluated well (managed are: curriculum resources, networking courses, lab facilities, ISO-based management. Resources have been used but not optimal role: resources module practice, the formulation of an internship, practice material / TA, the performance of IC-based lecturer

ANALISIS KESIAPAN PROGRAM STUDI DALAM PRODUCTION BASED EDUCATION: STUDI PADA PROGRAM STUDI D3 AKUNTANSI POLINES

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Muhammad Noor Ardiansah

2014-06-01

Full Text Available There has been no clear studies to identify, verify and analyze readiness program resources in order to study the implementation of PBE resulted in initial position (existing point is not clear that the priority programs and activities that are carried out per year tend to be responsive and not directed priorities. These conditions resulted in analysis of resource readiness courses in the management of production-based learning pattern PBE draw conducted This study aims to identify and verify and analyze readiness resources management courses in the pattern of production based learning, particularly in the Accounting Studies Program. This research is expected to be used to increase the effectiveness of learning and vocational education to improve the quality and relevance of polytechnic graduates. Total score was 33 the existence of resources from the scale of 12-60. The average score is 2.75. The average score was shown the position of Prodi's resources have been used, but its role is unclear (repeatable tend to have clearly defined functions, communicated and documented (defined. Resources have been managed, monitored and evaluated well (managed are: curriculum resources, networking courses, lab facilities, ISO-based management. Resources have been used but not optimal role: resources module practice, the formulation of an internship, practice material / TA, the performance of IC-based lecturer

A qualitative chemometric study of resin composite polymerization

Directory of Open Access Journals (Sweden)

Regina Ferraz Mendes

2008-01-01

Full Text Available Objective: An experiment was carried out to assess the effect produced by different polymerization techniques on resin composite color after it has been immersed in coffee. Methods: Samples were manufactured using TPH Spectrum composite. It was polymerized for 10 or 40 seconds, with the light tip at one or zero millimeters from the resin surface, and afterwards the samples were immersed in coffee for 24 hours or 7 days. Ten different evaluators classified the samples according to their degree of staining. Results: The samples that were polymerized for 10 seconds were more susceptible to staining than the ones polymerized by 40 seconds. Samples immersed in coffee for 7 days were more susceptible to staining than the ones immersed for 24 hours. Conclusion: The variables polymerization time and immersion time were determinant in the staining susceptibility of the studied composite by coffee. However, there was no significant difference, irrespective of whether the resin was polymerized 10 or zero millimeters away from the resin surface.

Future flare compositions

NARCIS (Netherlands)

Lingen, J.L.N. van; Meuken, D.; Hackspik, M.M.; Mäkeläinen, T.; Weiser, V.; Poulson, G.W.

2014-01-01

This poster describes the work done within the Category B joint research project under the European Defence Agency (EDA) on Future Flare Compositions [1]. Contributing members were Finland, Germany, United Kingdom and the Netherlands. The program was aimed to identify the technology gaps that apply

Optimization of composite sandwich cover panels subjected to compressive loadings

Science.gov (United States)

Cruz, Juan R.

1991-01-01

An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

Design a computational program to calculate the composition variations of nuclear materials in the reactor operations

International Nuclear Information System (INIS)

Mohmmadnia, Meysam; Pazirandeh, Ali; Sedighi, Mostafa; Bahabadi, Mohammad Hassan Jalili; Tayefi, Shima

2013-01-01

Highlights: ► The atomic densities of light and heavy materials are calculated. ► The solution is obtained using Runge–Kutta–Fehlberg method. ► The material depletion is calculated for constant flux and constant power condition. - Abstract: The present work investigates an appropriate way to calculate the variations of nuclides composition in the reactor core during operations. Specific Software has been designed for this purpose using C#. The mathematical approach is based on the solution of Bateman differential equations using a Runge–Kutta–Fehlberg method. Material depletion at constant flux and constant power can be calculated with this software. The inputs include reactor power, time step, initial and final times, order of Taylor Series to calculate time dependent flux, time unit, core material composition at initial condition (consists of light and heavy radioactive materials), acceptable error criterion, decay constants library, cross sections database and calculation type (constant flux or constant power). The atomic density of light and heavy fission products during reactor operation is obtained with high accuracy as the program outputs. The results from this method compared with analytical solution show good agreements

Computer Music Synthesis and Composition

Science.gov (United States)

Ayers, Lydia

What is computer music composition? Composers are using the computer for everything from MIDI instruments communicating with computer sequencers, pitch trackers analyzing the sounds of acoustic instruments and converting them to pitch information, live performers with recorded music, performers with interactive computer programs, computer music produced by dancers using sensors, automatic music composition with the computer programs composing the music, composing with sounds or parts of sounds rather than notes, how to structure the use of time, composing with timbres, or the colors of sounds, and timbre morphing, such as a gong morphing to a voice, composing with textures and texture morphing, such as fluttertonguing morphing to pitch, granular synthesis, trills and convolution.

Hot forming of composite prepreg : Experimental study

Science.gov (United States)

Tardif, Xavier; Duthille, Bertrand; Bechtel, Stephane; le Pinru, Louis; Campagne, Benjamin; Destombes, Gautier; Deshors, Antoine; Marchand, Christophe; Azzouzi, Khalid El; Moro, Tanguy

2017-10-01

The hot forming of thermoset prepreg consists in bending an uncured composite part by applying a mechanical constrain on the hot laminate. Most of the time, the mold is inserted in a vacuum box and the mechanical constrain is applied on the composite laminate by a single membrane or a double-membrane. But the performance improvement products resulted in forming increasingly complex parts with advanced materials having a less formability. These new complex parts require a finer comprehension of the process and an optimization of the key parameters to get acceptable quality. In this work, an experimental study has been carried out to identify the process conditions that do not lead to unacceptable defaults: undulations of fibers. In the present study, downward-bending has been evaluated with an original light mechanical forming concept, for a given stacking sequence. The influence of the part's temperature and the part's bending speed are investigated. To carry this study out, a hot forming test bench has been designed and manufactured to have a precise supervision of the process conditions. It is able to bend parts of 1500 mm length x 600 mm width x 20 mm thick.

Experimental and numerical study of the micro-mechanical failure in composites

DEFF Research Database (Denmark)

Ashouri Vajari, Danial; Martyniuk, Karolina; Sørensen, Bent F.

2013-01-01

The fibre/matrix interfacial debonding is found to be the first microscale failure mechanism leading to subsequent macroscale transverse cracks in composite materials under tensile load. In this paper, the micromechanical interface failure in fiber-reinforced composites is studied experimentally ...

The Linguistic Memory of Composition and the Rhetoric and Composition PhD: Forgetting (and Remembering) Language and Language Difference in Doctoral Curricula

Science.gov (United States)

Kilfoil, Carrie Byars

2017-01-01

This article analyzes the decline of linguistics in rhetoric and composition PhD programs in terms of the "linguistic memory" (Trimbur) of composition. Since the field of linguistics once offered the primary means for composition to address the structural, psychological, sociohistorical, and cultural dimensions of language in student…

Structural dynamics of shroudless, hollow fan blades with composite in-lays

Science.gov (United States)

Aiello, R. A.; Hirschbein, M. S.; Chamis, C. C.

1982-01-01

Structural and dynamic analyses are presented for a shroudless, hollow titanium fan blade proposed for future use in aircraft turbine engines. The blade was modeled and analyzed using the composite blade structural analysis computer program (COBSTRAN); an integrated program consisting of mesh generators, composite mechanics codes, NASTRAN, and pre- and post-processors. Vibration and impact analyses are presented. The vibration analysis was conducted with COBSTRAN. Results show the effect of the centrifugal force field on frequencies, twist, and blade camber. Bird impact analysis was performed with the multi-mode blade impact computer program. This program uses the geometric model and modal analysis from the COBSTRAN vibration analysis to determine the gross impact response of the fan blades to bird strikes. The structural performance of this blade is also compared to a blade of similar design but with composite in-lays on the outer surface. Results show that the composite in-lays can be selected (designed) to substantially modify the mechanical performance of the shroudless, hollow fan blade.

Self-Healing Composite of Thermoset Polymer and Programmed Super Contraction Fibers

Science.gov (United States)

Li, Guoqiang (Inventor); Meng, Harper (Inventor)

2016-01-01

A composition comprising thermoset polymer, shape memory polymer to facilitate macro scale damage closure, and a thermoplastic polymer for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a bio-mimetic close-then heal process. In use, the shape memory polymer serves to bring surfaces of a structural defect into approximation, whereafter use of the thermoplastic polymer for molecular scale healing allowed for movement of the thermoplastic polymer into the defect and thus obtain molecular scale healing. The thermoplastic can be fibers, particles or spheres which are used by heating to a level at or above the thermoplastic's melting point, then cooling of the composition below the melting temperature of the thermoplastic. Compositions of the invention have the ability to not only close macroscopic defects, but also to do so repeatedly even if another wound/damage occurs in a previously healed/repaired area.

A Strategy for Efficiently Verifying Requirements Specifications Using Composition and Invariants

Science.gov (United States)

2003-09-05

Colle - sur - Loup , France, Oct. 1984. Springer-Verlag. [34] J. Ramish. Empirical studies of compositional abstraction. Technical report, Naval Research...global to modular temporal rea- soning about programs. In K. R. Apt, editor, Proc. NATO Adv. Study Inst. on Logics and Models of Concurrent Systems, La

Studying creativity training programs: A methodological analysis

DEFF Research Database (Denmark)

Valgeirsdóttir, Dagný; Onarheim, Balder

2017-01-01

Throughout decades of creativity research, a range of creativity training programs have been developed, tested, and analyzed. In 2004 Scott and colleagues published a meta‐analysis of all creativity training programs to date, and the review presented here sat out to identify and analyze studies...... published since the seminal 2004 review. Focusing on quantitative studies of creativity training programs for adults, our systematic review resulted in 22 publications. All studies were analyzed, but comparing the reported effectiveness of training across studies proved difficult due to methodological...... inconsistencies, variations in reporting of results as well as types of measures used. Thus a consensus for future studies is called for to answer the question: Which elements make one creativity training program more effective than another? This is a question of equal relevance to academia and industry...

Experimental study of optical fibers influence on composite

Science.gov (United States)

Liu, Rong-Mei; Liang, Da-Kai

2010-03-01

Bending strength and elasticity modulus of composite, with and without embedded optical fibers, were experimentally studied. Two kinds of laminates, which were denoted as group 1 and group 2, were fabricated from an orthogonal woven glass/epoxy prepreg. Since the normal stress value becomes the biggest at the surface of a beam, the optical fibers were embedded at the outmost layer and were all along the loading direction. Four types of materials, using each kind of laminated prepreg respectively, were manufactured. The embedded optical fibers for the 4 material types were 0, 10, 30 and 50 respectively. Three-point bending tests were carried out on the produced specimens to study the influence of embedded optical fiber on host composite. The experimental results indicated that the materials in group 2 were more sensitive to the embedded optical fibers.

Investigation on mechanical properties of basalt composite fabrics (experiment study)

Science.gov (United States)

Talebi Mazraehshahi, H.; Zamani, H.

2010-06-01

To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1). Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2). Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3). Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4). Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one material with

In vitro study of nano-hydroxyapatite/chitosan–gelatin composites for bio-applications

Directory of Open Access Journals (Sweden)

Khaled R. Mohamed

2014-03-01

Full Text Available The present work aims to study the in vitro properties of nano-hydroxyapatite/chitosan–gelatin composite materials. In vitro behavior was performed in simulated body fluid (SBF to verify the formation of apatite layer onto the composite surfaces. The in vitro data proved the deposition of calcium and phosphorus ions onto hydroxyapatite /polymeric composite surfaces especially those containing high concentrations of polymer content. The degradation of the composites decreased with increase in the polymeric matrix content and highly decreased in the presence of citric acid (CA, especially these composites which contain 30% polymeric content. The water absorption of the composites increased with increase in the polymeric content and highly increased with CA addition. The Fourier transformed infrared reflectance (FT-IR and scanning electron microscope (SEM for the composites confirmed the formation of bone-like apatite layer on the composite surfaces, especially those containing high content of polymers (30% with 0.2 M of CA. These promising composites have suitable properties for bio-applications such as bone grafting and bone tissue engineering applications in the future.

In vitro study of transverse strength of fiber reinforced composites.

Science.gov (United States)

Mosharraf, R; Hashemi, Z; Torkan, S

2011-01-01

Reinforcement with fiber is an effective method for considerable improvement in flexural properties of indirect composite resin restorations. The aim of this in-vitro study was to compare the transverse strength of composite resin bars reinforced with pre-impregnated and non-impregnated fibers. Thirty six bar type composite resin specimens (3×2×25 mm) were constructed in three groups. The first group was the control group (C) without any fiber reinforcement. The specimens in the second group (P) were reinforced with pre-impregnated fibers and the third group (N) with non-impregnated fibers. These specimens were tested by the three-point bending method to measure primary transverse strength. Data were statistically analyzed with one way ANOVA and Tukey's tests. There was a significant difference among the mean primary transverse strength in the three groups (Ptransverse strength (Pstudy, it was concluded that reinforcement with fiber considerably increased the transverse strength of composite resin specimens, but impregnation of the fiber used implemented no significant difference in the transverse strength of composite resin samples.

Updating and testing of a Finnish method for mixed municipal solid waste composition studies.

Science.gov (United States)

Liikanen, M; Sahimaa, O; Hupponen, M; Havukainen, J; Sorvari, J; Horttanainen, M

2016-06-01

More efficient recycling of municipal solid waste (MSW) is an essential precondition for turning Europe into a circular economy. Thus, the recycling of MSW must increase significantly in several member states, including Finland. This has increased the interest in the composition of mixed MSW. Due to increased information needs, a method for mixed MSW composition studies was introduced in Finland in order to improve the national comparability of composition study results. The aim of this study was to further develop the method so that it corresponds to the information needed about the composition of mixed MSW and still works in practice. A survey and two mixed MSW composition studies were carried out in the study. According to the responses of the survey, the intensification of recycling, the landfill ban on organic waste and the producer responsibility for packaging waste have particularly influenced the need for information about the composition of mixed MSW. The share of biowaste in mixed MSW interested the respondents most. Additionally, biowaste proved to be the largest waste fraction in mixed MSW in the composition studies. It constituted over 40% of mixed MSW in both composition studies. For these reasons, the classification system of the method was updated by further defining the classifications of biowaste. The classifications of paper as well as paperboard and cardboard were also updated. The updated classification system provides more information on the share of avoidable food waste and waste materials suitable for recycling in mixed MSW. The updated method and the information gained from the composition studies are important in ensuring that the method will be adopted by municipal waste management companies and thus used widely in Finland. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of Requirements for Composite Structures for Aircraft and Space Applications

Science.gov (United States)

Raju, Ivatury S.; Elliot, Kenny B.; Hampton, Roy W.; Knight, Norman F., Jr.; Aggarwal, Pravin; Engelstad, Stephen P.; Chang, James B.

2010-01-01

In this report, the aircraft and space vehicle requirements for composite structures are compared. It is a valuable exercise to study composite structural design approaches used in the airframe industry and to adopt methodology that is applicable for space vehicles. The missions, environments, analysis methods, analysis validation approaches, testing programs, build quantities, inspection, and maintenance procedures used by the airframe industry, in general, are not transferable to spaceflight hardware. Therefore, while the application of composite design approaches from aircraft and other industries is appealing, many aspects cannot be directly utilized. Nevertheless, experiences and research for composite aircraft structures may be of use in unexpected arenas as space exploration technology develops, and so continued technology exchanges are encouraged.

Effects of Combined Vigorous Interval Training Program and Diet on Body Composition, Physical Fitness, and Physical Self-Perceptions Among Obese Adolescent Boys and Girls.

Science.gov (United States)

Rey, Olivier; Vallier, Jean-Marc; Nicol, Caroline; Mercier, Charles-Symphorien; Maïano, Christophe

2017-02-01

This study examined the effects of a five-week intervention combining vigorous interval training (VIT) with diet among twenty-four obese adolescents. Fourteen girls and ten boys (aged 14-15) schooled in a pediatric rehabilitation center participated. The VIT intensity was targeted and remained above 80% of maximal heart rate (HR) and over six kilocalories per minute. Pre- and postintervention measures were body composition (BMI, weight, body fat percentage), physical self-perceptions (PSP), physical fitness (6-min walking distance and work) and its associated physiological responses (HR peak and blood lactate concentration). A series of two-way analyses of variance or covariance controlling for weight loss were used to examine the changes. Significant improvements were found in body composition, physical fitness and PSP (endurance, activity level, sport competence, global physical self-concept and appearance). In addition, boys presented higher levels of perceived strength and global physical self-concept than girls. Finally, there was a significant increase in perceived endurance, sport competence, and global physical self-concept in girls only. This five-week VIT program combined with diet represents an effective means for improving body composition, physical fitness, and PSP in obese adolescents, the effects on PSP being larger among girls.

Preliminary design study of advanced composite blade and hub and nonmechanical control system for the tilt-rotor aircraft. Volume 2: Project planning data

Science.gov (United States)

1980-01-01

Project planning data for a rotor and control system procurement and testing program for modifications to the XV-15 tilt-rotor research demonstrator aircraft is presented. The design, fabrication, and installation of advanced composite blades compatible with the existing hub, an advanced composite hub, and a nonmechanical control system are required.

Blackbird Creek Monitoring Program to Study the impact of Climate Change and Land Use

Science.gov (United States)

Ozbay, G.; Chintapenta, L. K.; Roeske, K. P.; Stone, M.; Phalen, L.

2014-12-01

The Blackbird Creek Monitoring Program at Delaware State University continues to utilize various perspectives to study the dynamics of one of Delaware's most pristine ecosystems. The water quality of Blackbird Creek has been constantly monitored for 3 years and correlated with the rain and storm events. Soil nutrients composition has been studied by extracting the water associated with soil aggregates and analyzing the levels of different nutrients. Soil quality is also assessed for heavy metals to identify potential human impact that may affect the health of ecosystem. Within the Blackbird Creek there is a threat to native plant communities from invasive plant species as they alter the ecosystem dynamics. Saltmarsh cord grass (Spartina alterniflora) and common reed (Phragmites australius) are the common wetland plants. Aerial mapping of the creek has been conducted to determine the area covered by invasive plant species. The microbial community structure plays a key role in soil carbon and nitrogen cycles in the ecosystem. Molecular analysis has been performed to study the microbial diversity with respect to the type of marsh grasses. This program has also incorporated the use of diatoms as biological indicators to assess the health of ecosystem and correlate that data with physical and chemical water quality data. The abundance and diversity of macro fauna such as blue crabs, fish and other significant species has also been studied. Stable isotopic analysis of these macro fauna has also been performed to study the food web. The results from this program will be helpful in addressing environmental challenges and designing management strategies.

Study of novel carbon fiber composite used exfoliated carbon fibers

Energy Technology Data Exchange (ETDEWEB)

Toyoda, Masahiro [Oita Univ., 700 Dannoharu, Oita 870-1192 (Japan)], E-mail: toyoda22@cc.oita-u.ac.jp; Kohara, Ryotaro; Tsumura, Tomoki [Oita Univ., 700 Dannoharu, Oita 870-1192 (Japan); Mutoh, Hiroyuki; Sakai, Mototsugu [Toyohashi Univ. of Tech., Toyohashi 441-8580 (Japan)

2009-04-15

One of the applications for carbon nanotubes (CNTs), CNT composite has been studied to reinforce of polymer. However, CNTs have not shown enough reinforced effect, because of poor dispersibility of itself and low purification. These characteristics are connected with the lowering mechanical strength in CNT's reinforced polymer composite. On the other hand, exfoliated carbon fibers (ExCFs) prepared through electrochemical processing were found to have unique morphology such as nanometer or sub-micrometer sized fibrils and well dispersibility. Fabrication of composite using its ExCFs was investigated. ExCFs changed in nanometer-sized fibrils by using ultrasonication and CNTs dispersed by using ultrasonication were compounded with polymethyl methacrylate (PMMA) in situ process through polymerization, and then their mechanical properties were examined. Flexural strength and elasticity of PMMA composite reinforced by ExCFs increased 166 and 171% respectively at addition of only 2.0 wt.% comparison with bulk PMMA. There was no significant aggregation in fracture surface, and homogeneous dispersion of ExCFs throughout the PMMA matrix was recognized. It was better than that of PMMA composite reinforced by CNTs. Homogeneous dispersion might be strongly related to mechanical properties. ExCFs might be expected to be applied to nano-composite instead of CNTs.

Advanced technology composite aircraft structures

Science.gov (United States)

Ilcewicz, Larry B.; Walker, Thomas H.

1991-01-01

Work performed during the 25th month on NAS1-18889, Advanced Technology Composite Aircraft Structures, is summarized. The main objective of this program is to develop an integrated technology and demonstrate a confidence level that permits the cost- and weight-effective use of advanced composite materials in primary structures of future aircraft with the emphasis on pressurized fuselages. The period from 1-31 May 1991 is covered.

The use of bioelectrical impedance analysis for body composition in epidemiological studies

DEFF Research Database (Denmark)

Böhm, A; Heitmann, B L

2013-01-01

BACKGROUND/OBJECTIVES: Bioelectrical impedance analysis (BIA) is a relatively simple, inexpensive and non-invasive technique to measure body composition and is therefore suitable in field studies and larger surveys. SUBJECTS/METHODS: We performed an overview of BIA-derived body fat percentages (BF......%) from 55 published studies of healthy populations aged 6-80 years. In addition, the relationship between body mass index (BMI) and body composition is documented in the context of BIA as a good alternative to closely differentiate which composition of the body better relates to the risk...

Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

Science.gov (United States)

Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

2012-01-01

Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

Mechanical interaction of Engineered Cementitious Composite (ECC) reinforced with Fiber Reinforced Polymer (FRP) rebar in tensile loading

DEFF Research Database (Denmark)

Lárusson, Lárus Helgi; Fischer, Gregor; Jönsson, Jeppe

2010-01-01

This paper introduces a preliminary study of the composite interaction of Engineered Cementitious Composite (ECC), reinforced with Glass Fiber Reinforced Polymer (GFRP) rebar. The main topic of this paper will focus on the interaction of the two materials (ECC and GFRP) during axial loading......, particularly in post cracking phase of the concrete matrix. The experimental program carried out in this study examined composite behavior under monotonic and cyclic loading of the specimens in the elastic and inelastic deformation phases. The stiffness development of the composite during loading was evaluated...

Advanced composite elevator for Boeing 727 aircraft

Science.gov (United States)

1979-01-01

Detail design activities are reported for a program to develop an advanced composites elevator for the Boeing 727 commercial transport. Design activities include discussion of the full scale ground test and flight test activities, the ancillary test programs, sustaining efforts, weight status, and the production status. Prior to flight testing of the advanced composites elevator, ground, flight flutter, and stability and control test plans were reviewed and approved by the FAA. Both the ground test and the flight test were conducted according to the approved plan, and were witnessed by the FAA. Three and one half shipsets have now been fabricated without any significant difficulty being encountered. Two elevator system shipsets were weighed, and results validated the 26% predicted weight reduction. The program is on schedule.

Exercise affects body composition but not weight in postmenopausal women.

NARCIS (Netherlands)

Velthuis, M.J.; Schuit, A.J.; Peeters, P.H.M.; Monninkhof, E.M.

2009-01-01

OBJECTIVE: The aim of this study was to investigate the effect of a 12-month moderate-to-vigorous exercise program combining aerobic and muscle strength training on body composition among sedentary, postmenopausal women. METHODS: A randomized controlled trial was conducted. A total of 189 sedentary

The Super Efficient Refrigerator Program: Case study of a Golden Carrot program

Energy Technology Data Exchange (ETDEWEB)

Eckert, J B

1995-07-01

The work in this report was conducted by the Analytic Studies Division (ASD) of the National Renewable Energy Laboratory (NREL) for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Office of Building Technologies. This case study describes the development and implementation of the Super Efficient Refrigerator Program (SERP), which awarded $30 million to the refrigerator manufacturer that developed and commercialized a refrigerator that exceeded 1993 federal efficiency standards by at least 25%. The program was funded by 24 public and private utilities. As the first Golden Carrot program to be implemented in the United States, SERP was studied as an example for future `market-pull` efforts.

Study of carbon nanotubes based Polydimethylsiloxane composite films

International Nuclear Information System (INIS)

Shahzad, M I; Giorcelli, M; Shahzad, N; Guastella, S; Castellino, M; Jagdale, P; Tagliaferro, A

2013-01-01

Thanks to their remarkable characteristics, carbon nanotubes (CNTs) have fields of applications which are growing every day. Among them, the use of CNTs as filler for polymers is one of the most promising. In this work we report on Polydimethylsiloxane (PDMS) composites with different weight percentages (0.0% to 3.0%) of multiwall carbon nanotubes (MWCNTs) having diameter 10–30 nm and length 20–30 μm. To achieve optimum dispersion of CNTs in PDMS matrix, high speed mechanical stirring and ultrasonication were performed. By using the doctor blade technique, 70 μm thick uniform films were produced on glass. They were subsequently thermally cured and detached from the glass to get flexible and self standing films. The surface morphological study done by FESEM, shows that CNTs are well dispersed in the PDMS. Raman spectroscopy and FTIR were used to investigate the possible structural changes in the polymer composite. To examine the optical behavior UV-VIS spectroscopy was employed in both specular and diffused modes. A linear increase in absorption coefficient is found with the increasing percentage of CNTs while the transmittance decreases exponentially. The results confirm the dependence of optical limiting effect on the quantity of MWCNTs. Based on optical study, MWCNTs/PDMS composite films can be a promising material to extend performances of optical limiters against laser pulses, which is often required in lasing systems.

The stress analysis method for three-dimensional composite materials

Science.gov (United States)

Nagai, Kanehiro; Yokoyama, Atsushi; Maekawa, Zen'ichiro; Hamada, Hiroyuki

1994-05-01

This study proposes a stress analysis method for three-dimensionally fiber reinforced composite materials. In this method, the rule-of mixture for composites is successfully applied to 3-D space in which material properties would change 3-dimensionally. The fundamental formulas for Young's modulus, shear modulus, and Poisson's ratio are derived. Also, we discuss a strength estimation and an optimum material design technique for 3-D composite materials. The analysis is executed for a triaxial orthogonally woven fabric, and their results are compared to the experimental data in order to verify the accuracy of this method. The present methodology can be easily understood with basic material mechanics and elementary mathematics, so it enables us to write a computer program of this theory without difficulty. Furthermore, this method can be applied to various types of 3-D composites because of its general-purpose characteristics.

Strategies for Evaluating a Freshman Studies Program.

Science.gov (United States)

Ketkar, Kusum; Bennett, Shelby D.

1989-01-01

The study developed an economic model for the evaluation of Seaton Hall University's freshman studies program. Two techniques used to evaluate the economic success of the program are break-even analysis and elasticity coefficient. (Author/MLW)

Socioeconomic residential segregation and public housing policies. An approach from the Program “Mi Casa, Mi Vida”. Case study in the city of Cordoba, Argentina

Directory of Open Access Journals (Sweden)

Florencia Molinatti

2016-07-01

Full Text Available This paper aims to analyze the possible effects of the housing program “Mi Casa, Mi Vida” in socioeconomic residential segregation in the city of Córdoba (Argentina. These effects are estimated from the study of the socioeconomic residential composition (before and after the implementation of the program, the mapping of residential movements generated by the program and the application of bivariate autocorrelation techniques. Among the key findings, most of the program beneficiaries are concentrated in poor areas surrounded by others in similar conditions. This fact favors the existence of a large cluster of poverty in the peripheries of the city and promotes marginalization and social exclusion.

Analysis of composition of microbiomes: a novel method for studying microbial composition

Directory of Open Access Journals (Sweden)

Siddhartha Mandal

2015-05-01

Full Text Available Background: Understanding the factors regulating our microbiota is important but requires appropriate statistical methodology. When comparing two or more populations most existing approaches either discount the underlying compositional structure in the microbiome data or use probability models such as the multinomial and Dirichlet-multinomial distributions, which may impose a correlation structure not suitable for microbiome data. Objective: To develop a methodology that accounts for compositional constraints to reduce false discoveries in detecting differentially abundant taxa at an ecosystem level, while maintaining high statistical power. Methods: We introduced a novel statistical framework called analysis of composition of microbiomes (ANCOM. ANCOM accounts for the underlying structure in the data and can be used for comparing the composition of microbiomes in two or more populations. ANCOM makes no distributional assumptions and can be implemented in a linear model framework to adjust for covariates as well as model longitudinal data. ANCOM also scales well to compare samples involving thousands of taxa. Results: We compared the performance of ANCOM to the standard t-test and a recently published methodology called Zero Inflated Gaussian (ZIG methodology (1 for drawing inferences on the mean taxa abundance in two or more populations. ANCOM controlled the false discovery rate (FDR at the desired nominal level while also improving power, whereas the t-test and ZIG had inflated FDRs, in some instances as high as 68% for the t-test and 60% for ZIG. We illustrate the performance of ANCOM using two publicly available microbial datasets in the human gut, demonstrating its general applicability to testing hypotheses about compositional differences in microbial communities. Conclusion: Accounting for compositionality using log-ratio analysis results in significantly improved inference in microbiota survey data.

Studies on the optimization of deformation processed metal metal matrix composites

Energy Technology Data Exchange (ETDEWEB)

Ellis, Tim W. [Iowa State Univ., Ames, IA (United States)

1994-01-04

A methodology for the production of deformation processed metal metal matrix composites from hyper-eutectic copper-chromium alloys was developed. This methodology was derived from a basic study of the precipitation phenomena in these alloys encompassing evaluation of microstructural, electrical, and mechanical properties. The methodology developed produces material with a superior combination of electrical and mechanical properties compared to those presently available in commercial alloys. New and novel alloying procedures were investigated to extend the range of production methods available for these material. These studies focused on the use of High Pressure Gas Atomization and the development of new containment technologies for the liquid alloy. This allowed the production of alloys with a much more refined starting microstructure and lower contamination than available by other methods. The knowledge gained in the previous studies was used to develop two completely new families of deformation processed metal metal matrix composites. These composites are based on immissible alloys with yttrium and magnesium matrices and refractory metal reinforcement. This work extends the physical property range available in deformation processed metal metal matrix composites. Additionally, it also represents new ways to apply these metals in engineering applications.

Composites and blends from biobased materials

Energy Technology Data Exchange (ETDEWEB)

Kelley, S.S. [National Renewable Energy Laboratory, Golden, CO (United States)

1995-05-01

The program is focused on the development of composites and blends from biobased materials to use as membranes, high value plastics, and lightweight composites. Biobased materials include: cellulose derivative microporous materials, cellulose derivative copolymers, and cellulose derivative blends. This year`s research focused on developing an improved understanding of the molecular features that cellulose based materials with improved properties for gas separation applications. Novel cellulose ester membrane composites have been developed and are being evaluated under a collaborative research agreement with Dow Chemicals Company.

Study of Physical Properties of SiCw/Al Composites During Unloaded Thermal Cycling

Institute of Scientific and Technical Information of China (English)

ZHAO Xin-ming; TIAN zhi-gang; CHENG hua; ZHU Xiao-gang; CHEN Wen-li

2004-01-01

The thermal expansion coefficient of SiCw/Al composites squeeze cast during unloaded thermal cycling was determined and analyzed. The study had shown that the thermal expansion coefficient of SiCw/Al composites reduced greatly with temperature raising. The thermal expansion coefficient of artificial ageing treatment SiCw/Al composites during unloaded thermal cycling reduced gradually, while the thermal expansion coefficient of squeezing SiCw/Al composites increased gradually. In addition, the thermal expansion coefficient of SiCw/Al composites reduced drastically with fiber fraction increasing.

Regional food dishes in the Brazilian National School Food Program: Acceptability and nutritional composition

Directory of Open Access Journals (Sweden)

Diogo thimoteo da Cunha

2014-08-01

Full Text Available Objective: the objective of this study was to evaluate the nutritional composition and describe the acceptability of regional culinary dishes served to students from public schools of rural and urban areas. Methods: Ten Brazilian regional dishes were evaluated for acceptability and nutritional composition. the survey was conducted in schools located in rural and urban areas of two cities in the state of São Paulo. Dish acceptability was evaluated using leftover analysis and a 5-point facial hedonic scale. the adherence index was calculated and used as an indirect measure of acceptance, and the nutritional composition was calculated based on the technical files of each dish. Results: A total of 2,384 students from 20 schools participated in the study and 1,174 tasted and evaluated the dishes. the test using the 5-point facial hedonic scale demonstrated that five dishes (Caldo verde soup, persimmon jelly, chicken with okra, puréed cornmeal with spinach, and arugula pizza had an acceptability rate above 85.0%. the mean adherence indices were 57.3% and 55.6% in urban and rural environments, respectively. Analysis of the nutritional composition of regional dishes indicates that these dishes can partially meet macronutrient recommendations. Conclusion: the tested dishes can become part of school menus as they were accepted or partly accepted by the students regardless of school location, whether rural or urban. the cultural heritage is an important resource for the food sovereignty of a country and should be constantly encouraged.

Biological studies of the U.S. subseabed disposal program

International Nuclear Information System (INIS)

Gomez, L.S.; Marietta, M.G.; Hessler, R.R.; Smith, K.L. Jr.; Talbert, D.M.; Yayanos, A.A.; Jackson, D.W.

1980-01-01

The Subseabed Disposal Program (SDP) of the U.S. is assessing the feasibility of emplacing high level radioactive wastes (HLW) within deep-sea sediments and is developing the means for assessing the feasibility of the disposal practices of other nations. This paper discusses the role and status of biological research in the SDP. Studies of the disposal methods and of the conceived barriers (canister, waste form and sediment) suggest that biological knowledge will be principally needed to address the impact of accidental releases of radionuclides. Current experimental work is focusing on the deep-sea ecosystem to determine: (1) the structure of benthic communities, including their microbial component; (2) the faunal composition of deep midwater nekton; (3) the biology of deep-sea amphipods; (4) benthic community metabolism; (5) the rates of bacterial processes; (6) the metabolism of deep-sea animals, and (7) the radiation sensitivity of deep-sea organisms. A multi-compartment model is being developed to assess quantitatively, the impact (on the environment and on man) of releases of radionuclides into the sea

Composite wind turbine towers

Energy Technology Data Exchange (ETDEWEB)

Polyzois, D. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Civil Engineering

2008-07-01

This paper discussed experiments conducted to optimized the advanced composite materials such as fiberglass reinforced plastics (FRP) used to fabricate wind turbine towers. FRP materials are used in tubular steel, lattice, guyed, and reinforced concrete towers. The towers and turbine blades are transported in segments and assembled on-site, sometimes in offshore or remote locations.The FRP composites are used to build towers with a high strength-to-weight ratio as well as to provide resistance to chemical attacks and corrosion. Use of the materials has resulted in towers that do not require heavy installation equipment. Experimental programs were conducted to verify the structural behaviour of the tower structure's individual-scaled cells as well as to evaluate the performance of multi-cell assemblies. Joint assembly designs were optimized, and a filament winding machine was used to conduct the experimental study and to test individual cells. Failure mode analyses were conducted to determine local buckling and shear rupture. Tension, compression, and shear properties of the FRP materials were tested experimentally, and data from the test were then used to develop finite element models of the composite towers as well as to obtain load deflection curves and tip oscillation data. A case study of a 750 kW wind turbine in Churchill, Manitoba was used to test the design. tabs., figs.

Composites reinforcement by rods a SAS study

CERN Document Server

Urban, V; Pyckhout-Hintzen, W; Richter, D; Straube, E

2002-01-01

The mechanical properties of composites are governed by size, shape and dispersion degree of so-called reinforcing particles. Polymeric fillers based on thermodynamically driven microphase separation of block copolymers offer the opportunity to study a model system of controlled rod-like filler particles. We chose a triblock copolymer (PBPSPB) and carried out SAS measurements with both X-rays and neutrons, in order to characterize separately the hard phase and the cross-linked PB matrix. The properties of the material depend strongly on the way that stress is carried and transferred between the soft matrix and the hard fibers. The failure of the strain-amplification concept and the change of topological contributions to the free energy and scattering factor have to be addressed. In this respect the composite shows a similarity to a two-network system, i.e. interpenetrating rubber and rod-like filler networks. (orig.)

Neutron tolerance of advanced SiC-fiber/CVI-SiC composites

International Nuclear Information System (INIS)

Katoh, Y.; Kohyama, A.; Snead, L.L.; Hinoki, T.; Hasegawa, A.

2003-01-01

Fusion blankets employing a silicon carbide (SiC) fiber-reinforced SiC matrix composite (SiC/SiC composite) as the structural material provide attractive features represented by high cycle efficiency and extremely low induced radioactivity. Recent advancement in processing and utilization techniques and application studies in ceramic gas turbine and advanced transportation systems, SiC/SiC composites are steadily getting matured as industrial materials. Reference SiC/SiC composites for fusion structural applications have been produced by a forced-flow chemical vapor infiltration (FCVI) method using conventional and advanced near-stoichiometric SiC fibers and extensively evaluated primarily in Japan-US collaborative JUPITER program. In this work, effect of neutron irradiation at elevated temperatures on mechanical property of these composites is characterized. Unlike in conventional SiC/SiC composites, practically no property degradation was identified in advanced composites with a thin carbon interphase by a neutron fluence level of approximately 8dpa at 800C. (author)

Epigenome-wide association studies without the need for cell-type composition.

Science.gov (United States)

Zou, James; Lippert, Christoph; Heckerman, David; Aryee, Martin; Listgarten, Jennifer

2014-03-01

In epigenome-wide association studies, cell-type composition often differs between cases and controls, yielding associations that simply tag cell type rather than reveal fundamental biology. Current solutions require actual or estimated cell-type composition--information not easily obtainable for many samples of interest. We propose a method, FaST-LMM-EWASher, that automatically corrects for cell-type composition without the need for explicit knowledge of it, and then validate our method by comparison with the state-of-the-art approach. Corresponding software is available from http://www.microsoft.com/science/.

African Social Studies Program-1, 1988-89. Final Report. A Master's Degree Program for African Social Studies Leaders.

Science.gov (United States)

Indiana Univ., Bloomington.

This paper presents the final report on a project that brought African social studies education leaders to Indiana University (Bloomington) to take part in a Master's Degree program. The report contains a brief history of the program, a description of the program, a discussion of issues relating to acculturation, an evaluation, a list of…

Study on the nano-composite electroless coating of Ni-P/Ag

International Nuclear Information System (INIS)

Ma Hongfang; Tian Fang; Li Dan; Guo Qiang

2009-01-01

The nano-composite coating of Ni-P/Ag was obtained by adding silver nanoparticles to the Ni-P electroless plating solutions. The properties of the coating were tested by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), differential scanning calorimeter (DSC), X-ray diffraction (XRD) and microsclerometer. Silver nanoparticles changed the properties of the composite coating. The Ni-P electroless coating contains 12.23 wt.% P while the composite coating of Ni-P/Ag contains 11.17 wt.% P and 0.24 wt.% Ag. The hardness of the composite coating is bigger than that of Ni-P alloy coating. Differential scanning calorimeter studies showed the amorphous to crystalline transition with precipitation of Ni 3 P and Ni around 335 deg. C

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Science.gov (United States)

Sushama, D.

2014-10-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er2O3 doped TeO2-WO3-La2O3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

STUDI DESKRIPTIF KEPUASAN MAHASISWA TERHADAP KINERJA LEMBAGA PROGRAM STUDI DAN PASCA SARJANA UNNES

Directory of Open Access Journals (Sweden)

Joko Widodo

2012-09-01

Full Text Available Penelitian ini mendeskripsikan kepuasan mahasiswa pada layanan akademik program studi (Prodi dan program pascasarjana (PPs , Mendeskripsikan kinerja akademik program studi dan program pascasarjana, Mendeskripsikan faktor-faktor yang mendukung kinerja akademik prodi dan PPs. Populasi penelitian ini adalah mahasiswa PPs aktif S2 semester 2 berjumlah 621 orang. Sedangkan sampel penelitian diambil secara simple random sampling berjumlah 102 orang. Hasil penelitian menunjukkan Kepuasan mahasiswa terhadap layanan akademik baik pada lingkup Prodi maupun lingkup PPs tergolong dalam kategori baik, Deskripsi hasil kinerja akademik Prodi, secara umum termasuk kategori baik, Berdasarkan hasil deskripsi enam indikator kinerja akademik PPs, secara umum rata-rata berada pada kategori baik.  Kinerja akademik PPs ditentukan oleh indikator sarana prasarana pendidikan (tangibles, kehandalan dosen dan staf (reliability, sikap tanggap dosen dan staf akademik (responsibility, perlakuan dosen dan staf pada mahasiswa (assurance, pemahaman terhadap kepentingan mahasiswa (emphaty, dan kepuasan mahasiswa (satisfaction. Saran yang diberikan hendaknya Program pascasarjana perlu mendorong peningkatan jumlah dosen dengan kualifikasi doktor (S3 sehingga layanan akademik perkuliahan dapat meningkat dan berdampak pula pada kinerja akademik secara keseluruhan.This study aimed to describe student satisfaction in the service of academic of study program  and graduate programs , describing the academic performance of study program and graduate program,  describes the factors that support academic performance of study program and graduate program. The population are active graduate students who are in second semester, the  total number is  621 people. While the study sample is taken by simple random sampling, total sample is 102 people. Results show that student satisfaction for academic services in both  study programs and graduate programs are  in  good

Investigation on mechanical properties of basalt composite fabrics (experiment study

Directory of Open Access Journals (Sweden)

Talebi Mazraehshahi H.

2010-06-01

Full Text Available To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1. Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2. Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3. Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4. Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one

On the Mechanical Behavior of Advanced Composite Material Structures

Science.gov (United States)

Vinson, Jack

During the period between 1993 and 2004, the author, as well as some colleagues and graduate students, had the honor to be supported by the Office of Naval Research to conduct research in several aspects of the behavior of structures composed of composite materials. The topics involved in this research program were numerous, but all contributed to increasing the understanding of how various structures that are useful for marine applications behaved. More specifically, the research topics focused on the reaction of structures that were made of fiber reinforced polymer matrix composites when subjected to various loads and environmental conditions. This included the behavior of beam, plate/panel and shell structures. It involved studies that are applicable to fiberglass, graphite/carbon and Kevlar fibers imbedded in epoxy, polyester and other polymeric matrices. Unidirectional, cross-ply, angle ply, and woven composites were involved, both in laminated, monocoque as well as in sandwich constructions. Mid-plane symmetric as well as asymmetric laminates were studied, the latter involving bending-stretching coupling and other couplings that only can be achieved with advanced composite materials. The composite structures studied involved static loads, dynamic loading, shock loading as well as thermal and hygrothermal environments. One major consideration was determining the mechanical properties of composite materials subjected to high strain rates because the mechanical properties vary so significantly as the strain rate increases. A considerable number of references are cited for further reading and study for those interested.

A New Highly Bioactive Composite for Scaffold Applications: A Feasibility Study

Directory of Open Access Journals (Sweden)

Antonella Sola

2011-01-01

Full Text Available Hydroxyapatite (HA has been widely investigated as scaffolding material for bone tissue engineering, mainly for its excellent biocompatibility. Presently, there is an increasing interest in the composites of hydroxyapatite with bioactive glasses, with the aim to obtain systems with improved bioactivity or mechanical properties. Moreover, modifying the ratio between bioactive glass and hydroxyapatite results in the possibility of controlling the reaction rate of the composite scaffold in the human body. However, high temperature treatments are usually required in order to sinter HA-based composites, causing the bioactive glass to crystallize into a glass-ceramic, with possible negative effects on its bioactivity. In the present research work, a glass composition belonging to the Na2O-CaO-P2O5-SiO2 system, with a reduced tendency to crystallize, is applied to realize HA-based composites. The novel samples can be sintered at a relative low temperature (750 °C compared to the widely studied HA/45S5 Bioglass® composites. This fact greatly helps to preserve the amorphous nature of the glass, with excellent effects in terms of bioactivity, according to in vitro tests. As a first application, the obtained composites are also tested to realize highly porous scaffolds by means of the standard burning out method.

A Study of Flexible Composites for Expandable Space Structures

Science.gov (United States)

Scotti, Stephen J.

2016-01-01

Payload volume for launch vehicles is a critical constraint that impacts spacecraft design. Deployment mechanisms, such as those used for solar arrays and antennas, are approaches that have successfully accommodated this constraint, however, providing pressurized volumes that can be packaged compactly at launch and expanded in space is still a challenge. One approach that has been under development for many years is to utilize softgoods - woven fabric for straps, cloth, and with appropriate coatings, bladders - to provide this expandable pressure vessel capability. The mechanics of woven structure is complicated by a response that is nonlinear and often nonrepeatable due to the discrete nature of the woven fiber architecture. This complexity reduces engineering confidence to reliably design and certify these structures, which increases costs due to increased requirements for system testing. The present study explores flexible composite materials systems as an alternative to the heritage softgoods approach. Materials were obtained from vendors who utilize flexible composites for non-aerospace products to determine some initial physical and mechanical properties of the materials. Uniaxial mechanical testing was performed to obtain the stress-strain response of the flexible composites and the failure behavior. A failure criterion was developed from the data, and a space habitat application was used to provide an estimate of the relative performance of flexible composites compared to the heritage softgoods approach. Initial results are promising with a 25% mass savings estimated for the flexible composite solution.

Study of Plasma Electrolytic Oxidation Coatings on Aluminum Composites

Directory of Open Access Journals (Sweden)

Leonid Agureev

2018-06-01

Full Text Available Coatings, with a thickness of up to 75 µm, were formed by plasma electrolytic oxidation (PEO under the alternating current electrical mode in a silicate-alkaline electrolyte on aluminum composites without additives and alloyed with copper (1–4.5%. The coatings’ structure was analyzed by scanning electron microscopy, X-ray microanalysis, X-ray photoelectron spectroscopy, nuclear backscattering spectrometry, and XRD analysis. The coatings formed for 60 min were characterized by excessive aluminum content and the presence of low-temperature modifications of alumina γ-Al2O3 and η-Al2O3. The coatings formed for 180 min additionally contained high-temperature corundum α-Al2O3, and aluminum inclusions were absent. The electrochemical behavior of coated composites and uncoated ones in 3% NaCl was studied. Alloyage of aluminum composites with copper increased the corrosion current density. Plasma electrolytic oxidation reduced it several times.

Developmental assessment of the Fort St. Vrain version of the Composite HTGR Analysis Program (CHAP-2)

International Nuclear Information System (INIS)

Stroh, K.R.

1980-01-01

The Composite HTGR Analysis Program (CHAP) consists of a model-independent systems analysis mainframe named LASAN and model-dependent linked code modules, each representing a component, subsystem, or phenomenon of an HTGR plant. The Fort St. Vrain (FSV) version (CHAP-2) includes 21 coded modules that model the neutron kinetics and thermal response of the core; the thermal-hydraulics of the reactor primary coolant system, secondary steam supply system, and balance-of-plant; the actions of the control system and plant protection system; the response of the reactor building; and the relative hazard resulting from fuel particle failure. FSV steady-state and transient plant data are being used to partially verify the component modeling and dynamic smulation techniques used to predict plant response to postulated accident sequences

Ceramic composites for near term reactor application - HTR2008-58050

International Nuclear Information System (INIS)

Snead, L. L.; Katoh, Y.; Windes, W. E.; Shinavski, R. J.; Burchell, T. D.

2008-01-01

Currently, two composites types are being developed for in-core application: carbon fiber carbon composite (CFC), and silicon carbide fiber composite (SiC/SiC.) Irradiation effects studies have been carried out over the past few decades yielding radiation-tolerant CFC's and a composite of SiC/SiC with no apparent degradation in mechanical properties to very high neutron exposure. While CFC's can be engineered with significantly higher thermal conductivity, and a slight advantage in manufacturability than SiC/SiC, they do have a neutron irradiation-limited lifetime. The SiC composite, while possessing lower thermal conductivity (especially following irradiation), appears to have mechanical properties insensitive to irradiation. Both materials are currently being produced to sizes much larger than that considered for nuclear application. In addition to materials aspects, results of programs focusing on practical aspects of deploying composites for near-term reactors will be discussed. In particular, significant progress has been made in the fabrication, testing, and qualification of composite gas-cooled reactor control rod sheaths and the ASTM standardization required for eventual qualification. (authors)

Chromium picolinate effects on body composition and muscular performance in wrestlers.

Science.gov (United States)

Walker, L S; Bemben, M G; Bemben, D A; Knehans, A W

1998-12-01

The purpose of this study was to assess the effects of 14 wk of chromium picolinate supplementation during the final 16 wk of a preseason resistance and conditioning program on body composition and neuromuscular performance in NCAA Division I wrestlers. During this phase of training, wrestlers are primarily interested in trying to improve physical performance and wrestling technique and are not engaged in severe, acute weight loss practices commonly employed before competition. This double-blinded, randomized placebo-controlled study involved 20 wrestlers from the University of Oklahoma assigned to either a treatment group (Cr+3; N = 7; 20.4 yr +/- 0.1) receiving 200 micrograms chromium picolinate daily, a placebo group (P; N = 7; 19.9 yr +/- 0.2), or a control group (C; N = 6; 20.2 yr +/- 0.1) using a stratified random sampling technique based on weight classification. Body composition, neuromuscular performance, metabolic performance, and serum insulin and glucose were measured before and immediately following the supplementation and training period. Repeated measures ANOVA indicated no significant changes in body composition for any of the groups. Aerobic power increased significantly (P pre- to post-test changes in bench press power were significant. These results suggest that chromium picolinate supplementation coupled with a typical preseason training program does not enhance body composition or performance variables beyond improvements seen with training alone.

Thermal performance study of form-stable composite phase change material with polyacrylic

Science.gov (United States)

Kee, Shin Yiing; Munusamy, Yamuna; Ong, Kok Seng; Chee, Swee Yong; Sanmuggam, Shimalaa

2017-04-01

Phase change material (PCM) is one of the most popular and widely used as thermal energy storage material because it is able to absorb and release a large amount of latent heat during a phase change process over a narrow temperature range. In this work, the form-stable composite PCM was prepared by blending of PMMA and myristic acid in different weight percentage. PMMA was used as a supporting material while myristic acid was used as PCM. Theoretically, PCM can be encapsulated in the support material after blending. However, a small amount of liquid PCMs can leak out from supporting material due to the volume change in phase change process. Therefore, a form-stable composite PCM with polyacrylic coating was studied. Leakage test was carried out to determine the leakage percentage of the form-stable composite PCM. Fourier transform infrared spectroscopy (FTIR) was used to characterize the chemical compatibility of the form-stable PCM composite while differential scanning calorimetry (DSC) was used to study the melting, freezing point and the latent heat of melting and freezing for the form-stable composite PCM.

Study on Carbon Nano composite Counter electrode for Dye-Sensitized Solar Cells

International Nuclear Information System (INIS)

Chen, Y.; Zhang, H.; Lin, J.

2012-01-01

Carbon nano composite electrodes were prepared by adding carbon nano tubes (CNTs) into carbon black as counter electrodes of dye-sensitized solar cells (DSSCs). The morphology and structure of carbon nano composite electrodes were studied by scanning electron microscopy. The influence of CNTs on the electrochemical performance of carbon nano composite electrodes is investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Carbon nano composite electrodes with CNTs exhibit a highly interconnected network structure with high electrical conductivity and good catalytic activity. The influence of different CNTs content in carbon nano composite electrodes on the open-circuit voltage, short-circuit current, and filling factor of DSSCs is also investigated. DSSCs with 10% CNTs content exhibit the best photovoltaic performance in our experiments.

Phase 2B experimental design for the INEEL glass composition variation study

International Nuclear Information System (INIS)

Peeler, D.

2000-01-01

The U.S. Department of Energy's (DOE's) Offices of Science and Technology (through the Tanks Focus Area [TFA]) and Waste Management are sponsoring a partnership among Idaho National Engineering and Environmental Laboratory (INEEL), Pacific Northwest National Laboratory (PNNL), and the Savannah River Technology Center (SRTC) for a collaborative glass composition variation study (CVS). The purpose of the CVS is to investigate property - composition relationships within a glass-composition region compatible with the expected range of Idaho Nuclear Technology and Engineering Center (INTEC) high-activity wastes (HAWs). The CVS has been conducted in phases to allow INEEL, PNNL, and SRTC researchers to adjust the glass composition region of interest as flowsheet options are refined and/or waste-stream compositions become more defined

Bibliography of Ethnic Heritage Studies Program Materials.

Science.gov (United States)

Kotler, Greta; And Others

The Ethnic Heritage Studies Program was designed to teach students about the nature of their heritage and to study the contributions of the cultural heritage of other ethnic groups. This is a bibliography of materials developed by projects which received Federal Ethnic Heritage Studies Program grants during fiscal year 1974-75 and 1975-76.…

US country studies program: Results from mitigation studies

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This paper describes the U.S. Country Studies Program which was implemented to support the principles and objectives of the Framework Convention on Climate Change (FCCC). There were three principle objectives in this program: to enhance capabilities to conduct climate change assessments, prepare action plans, and implement technology projects; to help establish a process for developing and implementing national policies and measures; to support principles and objective of the FCCC. As a result, 55 countries are completing studies, more than 2000 analysts engaged in the studies have been trained, and there is a much broader understanding and support for climate change concerns. The article describes experiences of some countries, and general observations and conclusions which are broadly seperated into developed countries and those with economies in transition.

Study on the heat-resistant EB curing composites

International Nuclear Information System (INIS)

Bao Jianwen; Li Yang; Li Fengmei

2000-01-01

There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. The effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

A preliminary study on PVDC modified composite materials of protective for tritium

International Nuclear Information System (INIS)

Wan Xiaoli; Dan Guiping; Li Ye; Wen Wei; Zhang Dong

2012-01-01

Through the experimental device, the HTO permeation performances of two kinds of PVDC modified composite materials were studied. The characteristic curves of the two composite materials were ascertained, and various other packing materials with anti-tritium permeation performance were compared. (authors)

Study of optical properties of Erbium doped Tellurite glass-polymer composite

Energy Technology Data Exchange (ETDEWEB)

Sushama, D., E-mail: sushasukumar@gmail.com [Research Awardee, LAMP, Dept. of Physics, Nit, Calicut, India and Dept. of Physics, M.S.M. College, Kayamkulam, Kerala (India)

2014-10-15

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er{sub 2}O{sub 3} doped TeO{sub 2}‐WO{sub 3}‐La{sub 2}O{sub 3} Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption.

Study of optical properties of Erbium doped Tellurite glass-polymer composite

International Nuclear Information System (INIS)

Sushama, D.

2014-01-01

Chalcogenide glasses have wide applications in optical device technology. But it has some disadvantages like thermal instability. Among them Tellurite glasses exhibits high thermal Stability. Doping of rare earth elements into the Tellurite glasses improve its optical properties. To improve its mechanical properties composites of this Tellurite glasses with polymer are prepared. Bulk samples of Er 2 O 3 doped TeO 2 ‐WO 3 ‐La 2 O 3 Tellurite glasses are prepared from high purity oxide mixtures, melting in an alumina crucible in air atmosphere. Composites of this Tellurite glasses with polymer are prepared by powder mixing method and the thin films of these composites are prepared using polymer press. Variations in band gap of these composites are studied from the UV/Vis/NIR absorption

Modeling of combustion products composition of hydrogen-containing fuels

International Nuclear Information System (INIS)

Assad, M.S.

2010-01-01

Due to the usage of entropy maximum principal the algorithm and the program of chemical equilibrium calculation concerning hydrogen--containing fuels are devised. The program enables to estimate the composition of combustion products generated in the conditions similar to combustion conditions in heat engines. The program also enables to reveal the way hydrogen fraction in the conditional composition of the hydrocarbon-hydrogen-air mixture influences the harmful components content. It is proven that molecular hydrogen in the mixture is conductive to the decrease of CO, CO 2 and CH x concentration. NO outlet increases due to higher combustion temperature and N, O, OH concentrations in burnt gases. (authors)

DMA Modern Programming Environment Study.

Science.gov (United States)

1980-01-01

capabilities. The centers are becoming increasingly dependent upon the computer and digital data in the fulfillment of MC&G goals. Successful application...ftticrcsrccessors C140 by Herbert AlteroDigital Citmmuncaticns C141 0 Structuredl Design ’-:orkshocr by Ned Chapin KC 156o Digital Systems En17lrceriirg CC 139 o3...on a programming environment. The study, which resulted in production of a paper entitled An EXEC 8 Programming Support Libary , contends that most of

Fatigue behaviour study on repaired aramid fiber/epoxy composites

Directory of Open Access Journals (Sweden)

Edson Cocchieri Botelho

2009-06-01

Full Text Available Aramid fiber reinforced polymer composites have been used in a wide variety of applications, such as aerospace, marine, sporting equipment and in the defense sector, due to their outstanding properties at low density. The most widely adopted procedure to investigate the repair of composites has been by repairing damages simulated in composite specimens. This work presents the structural repair influence on tensile and fatigue properties of a typical aramid fiber/epoxy composite used in the aerospace industry. According to this work, the aramid/epoxy composites with and without repair present tensile strength values of 618 and 680MPa, respectively, and tensile modulus of 26.5 and 30.1 GPa, respectively. Therefore, the fatigue results show that in loads higher than 170 MPa, both composites present a low life cycle (lower than 200,000 cycles and the repaired aramid/epoxy composite presented low fatigue resistance in low and high cycle when compared with non-repaired composite. With these results, it is possible to observe a decrease of the measured mechanical properties of the repaired composites.

Physical activity and body composition, body physique, and quality of life in premenopausal breast cancer patients during endocrine therapy--a feasibility study.

Science.gov (United States)

Hojan, Katarzyna; Molińska-Glura, Marta; Milecki, Piotr

2013-02-01

Endocrine therapy (ET) is a common method of treatment in breast cancer patients; however, its negative impact on body composition, body physique (physical body shape/measurements), and quality of life (QoL) remains controversial. Previous studies have shown physical exercise can have a positive effect on QoL in breast cancer patients, especially premenopausal subjects. In this feasibility study, we sought to assess the impact that physical exercise had on body composition and QoL in premenopausal breast cancer patients undergoing ET, and to determine the appropriateness of further testing of this intervention in this patient group. This study involved 41 premenopausal female breast cancer patients before and after six, 12, and 18 months of ET. Aerobic training began in the 6th month and resistance training was added in the 12th month. Body composition was evaluated using dual-energy x-ray absorptiometry (DXA) scans, body physique was evaluated using anthropometric measurement techniques, and QoL was evaluated using questionnaires from the European Organization for Research and Treatment of Cancer. The initial period of ET with no exercise resulted in a reduction in fat-free body mass (FFBM), an increase in fat body mass (FBM), and a decline in QoL scores. Adding aerobic training resulted in a reduction of FBM and percentage of android fat, and improved QoL scores. The introduction of resistance training further reduced percentage of android and gynoid fat, increased FFBM, and further improved QoL scores. ET negatively impacts body composition, body physique, and QoL of premenopausal breast cancer patients. This feasibility study shows that physical activity may improve QoL and reduce adverse effects of ET on body composition and body physique, indicating appropriateness for further investigation on the use of exercise programs in premenopausal breast cancer patients to improve the outcomes of therapy.

Cooperative program for design, fabrication, and testing of graphite/epoxy composite helicopter shafting

Science.gov (United States)

Wright, C. C.; Baker, D. J.; Corvelli, N.; Thurston, L.; Clary, R.; Illg, W.

1971-01-01

The fabrication of UH-1 helicopter tail rotor drive shafts from graphite/epoxy composite materials is discussed. Procedures for eliminating wrinkles caused by lack of precure compaction are described. The development of the adhesive bond between aluminum end couplings and the composite tube is analyzed. Performance tests to validate the superiority of the composite materials are reported.

Study on erosion behaviour of hybrid aluminium composite

Science.gov (United States)

Vishwas, D. K.; Chandrappa, C. N.; Venkatesh, Shreyas

2018-04-01

The origin of the light metals, as compared to other metals in this century, is noticeable and an exciting area of expansion for innovation. Light metals, are need of the day in engineering, among them application of aluminium and its alloys is enormous. we observe that these metals tend to have a progressive loss of metal from having contact surface with other metals. Erosion is one such wear process, where damage occurs by the repeated application of high localised stresses. Erosion due to impact of solid particle, is a significant problem. In the present work, the erosion behaviour of hybrid aluminium composite is studied. AL 6061 is used as the base alloy. AL 6061 alloy has excellent corrosion resistance but poor wear resistance. So, in order to have improved properties, it is reinforced with Tungsten Chromium Nickel powder in varied proportions by the method of stir casting. The results are compared with the as-cast Al-alloy to determine the improvement in mechanical properties. The tests were conducted in ASTM G76 setup, to determine solid particle erosion behaviour and the results of the hybrid composite were compared with that of as-cast AL 6061 alloy. It was evident that mass loss was maximum at 300 inclinations, which is a characteristic of ductile materials. It was observed that upon increasing the percentages of reinforcement (wt.%), the wear resistance of the hybrid composite increased significantly. It was also observed that the inclusion of tungsten-chromium-nickel powder increased the hardness of the hybrid composite significantly.

Gut microbiota composition may relate to weight loss rate in obese pet dogs

DEFF Research Database (Denmark)

Kieler, Ida Nordang; Kamal, Shamrulazhar; Vitger, Anne Désiré

2017-01-01

Obese dogs seem to have a different gut microbiome (GM) composition compared to lean dogs, and in humans, GM composition may negatively impact the ability to lose weight in some individuals. The purpose of this study was to investigate the interaction between exercise, weight-loss and the composi......Obese dogs seem to have a different gut microbiome (GM) composition compared to lean dogs, and in humans, GM composition may negatively impact the ability to lose weight in some individuals. The purpose of this study was to investigate the interaction between exercise, weight......-loss and the composition of GM in dogs. Eighteen obese pet dogs were recruited for a 12-week weight-loss intervention. All dogs were fed restrictively with a commercial high-protein/high-fibre dry diet, and eight of these dogs were enrolled in an exercise program in addition to the diet intervention. Faecal samples were...

Physical studies of transmutation scenarios. The Muse program with the Masurca facility: a step towards an hybrid demonstrator?

International Nuclear Information System (INIS)

Bouchard, J.; Leconte, Ph.; Doubre, H.; Bhatnagar, V.P.; Carbonnier, J.L.; Chawla, R.; Bernard, H.

2002-01-01

The Muse research program, which started in 1995, is a contribution to the development of a dedicated subcritical accelerator driven system (ADS) for the transmutation of minor actinides produced by conventional nuclear power plants. The Muse experiments aim at making a parametric study of different reactor core compositions with different subcritical levels and supplied by different sources in order to demonstrate that the measurement techniques and the calculation charts established for critical FBRs remain valid with an hybrid system. The 4. phase of the Muse program concerns the design, realization and installation of the Genepi (generator of intense pulse neutrons) deutons accelerator at the Masurca facility of Cadarache (France) for the understanding of the neutronic behaviour of an ADS, the definition of a reference calculation scheme, and the development of specific experimental techniques for dynamical measurements. This document brings together the presentations (transparencies) given at the SFEN technical meeting of May 30, 2002 about the Muse program. (J.S.)

"Embarrassingly White": Faculty Racial Disparities in American Recreation, Park, and Tourism Programs

Science.gov (United States)

Mowatt, Rasul A.; Johnson, Corey W.; Roberts, Nina S.; Kivel, B. Dana

2016-01-01

The recruitment and retention of faculty and students of color is a long-standing challenge in academic programs focusing on leisure studies, parks, recreation, and tourism. However, when confronting the predominantly white composition of educational programs, many evade or, at most, acknowledge the situation as a "deficit." Few offer…

A Study of Nanoclay Reinforcement of Biocomposites Made by Liquid Composite Molding

Directory of Open Access Journals (Sweden)

Farida Bensadoun

2011-01-01

Full Text Available Liquid composite molding (LCM processes are widely used to manufacture composite parts for the automotive industry. An appropriate selection of the materials and proper optimization of the manufacturing parameters are keys to produce parts with improved mechanical properties. This paper reports on a study of biobased composites reinforced with nanoclay particles. A soy-based unsaturated polyester resin was used as synthetic matrix, and glass and flax fiber fabrics were used as reinforcement. This paper aims to improve mechanical and flammability properties of reinforced composites by introducing nanoclay particles in the unsaturated polyester resin. Four different mixing techniques were investigated to improve the dispersion of nanoclay particles in the bioresin in order to obtain intercalated or exfoliated structures. An experimental study was carried out to define the adequate parameter combinations between vacuum pressure, filling time, and resin viscosity. Two manufacturing methods were investigated and compared: RTM and SCRIMP. Mechanical properties, such as flexural modulus and ultimate strength, were evaluated and compared for conventional glass fiber composites (GFC and flax fiber biocomposites (GFBiores-C. Finally, smoke density analysis was performed to demonstrate the effects and advantages of using an environment-friendly resin combined with nanoclay particles.

Hydrogen storage study on Ti2CrV and ZrFe1.8V0.2 composite system

International Nuclear Information System (INIS)

Banerjee, S.; Kumar, A.; Pillai, C.G.S.; Sudarsan, V.

2012-01-01

Ti 2 CrV is reported to have one of the highest hydrogen storage capacities (more than 4 wt. %) among the bcc phase transition metal alloys. It has been found from the earlier study that Ti 2 CrV alloy shows quite good hydrogen absorption property but the desorption temperature is on the higher side. The in-situ temperature programmed desorption profile shows that the hydrogen desorption starts from 120℃ and the desorption peak comes at 180℃, which is slightly high for the vehicular application. On the other hand ZrFe 1.8 V 0.2 Laves phase alloy has low hydrogen absorption capacity, but at the room temperature it can desorp all its hydrogen. The pressure composition isotherm of ZrFe 1.8 V 0.2 alloy generated during the experiment shows the typical characteristics of the room temperature reversible hydride. The in-situ temperature programmed desorption shows that the hydride can desorb all the hydrogen below room temperature

Study of corrosive-erosive wear behaviour of Al6061/albite composites

International Nuclear Information System (INIS)

Sharma, S.C.; Krishna, M.; Murthy, H.N. Narasimha; Tarachandra, R.; Satyamoorthy, M.; Bhattacharyya, D.

2006-01-01

This investigation analyses the influence of dispersed alumina particles on the wear behaviour of the Al/albite composites in a corrosive environment. The composites were prepared by modified pressure die-casting technique. The corrosive-erosive wear experiments were carried out on a proprietary corrosion-erosion wear tester to study the wear characteristics of the composites. The slurry was made up of water and alumina (size: 90-150 μm, proportion: 0-30 wt.%), while H 2 SO 4 (0.01, 0.1 and 1N) was added to create the corrosive conditions. Experiments were arranged to test the relationships among the corrosive-erosive wear rate, concentrations of H 2 SO 4 and alumina in the slurry, weight percent of albite in the composite, erosion speed and distance. Wear rate varies marginally at low speeds but sharply increases at higher speeds. The corrosive wear rate logarithmically increased with the increasing concentration of the corrosive medium. The effect of abrasive particles and corrosion medium on the wear behaviour of the composite is explained experimentally, theoretically and using scanning electron microscopy

Feasibility of generating quantitative composition images in dual energy mammography: a simulation study

Science.gov (United States)

Lee, Donghoon; Kim, Ye-seul; Choi, Sunghoon; Lee, Haenghwa; Choi, Seungyeon; Kim, Hee-Joung

2016-03-01

Breast cancer is one of the most common malignancies in women. For years, mammography has been used as the gold standard for localizing breast cancer, despite its limitation in determining cancer composition. Therefore, the purpose of this simulation study is to confirm the feasibility of obtaining tumor composition using dual energy digital mammography. To generate X-ray sources for dual energy mammography, 26 kVp and 39 kVp voltages were generated for low and high energy beams, respectively. Additionally, the energy subtraction and inverse mapping functions were applied to provide compositional images. The resultant images showed that the breast composition obtained by the inverse mapping function with cubic fitting achieved the highest accuracy and least noise. Furthermore, breast density analysis with cubic fitting showed less than 10% error compare to true values. In conclusion, this study demonstrated the feasibility of creating individual compositional images and capability of analyzing breast density effectively.

Cross-lagged associations between children's stress and adiposity: the Children's Body Composition and Stress study.

Science.gov (United States)

Michels, Nathalie; Sioen, Isabelle; Boone, Liesbet; Clays, Els; Vanaelst, Barbara; Huybrechts, Inge; De Henauw, Stefaan

2015-01-01

The public health threats stress and adiposity have previously been associated with each other. Longitudinal studies are needed to reveal whether this association is bidirectional and the moderating factors. In the longitudinal Children's Body Composition and Stress study, 316 children (aged 5-12 years) had measures of stress (questionnaires concerning negative life events, problem behavior, and emotions) and adiposity (body mass index, waist-to-height ratio, and fat percentage) in three waves at 1-year intervals. The bidirectionality of the association between stress and adiposity was examined using cross-lagged analyses. We tested moderation by cortisol and life-style (physical activity, screen time, food consumption, eating behavior and sleep duration). Adiposity (body mass index: β = 0.48 and fat percentage: β = 0.18; p stress levels, but stress was not directly related to subsequent increases in adiposity indices. Cortisol and life-style factors displayed a moderating effect on the association between stress and adiposity. Stress was positively associated with adiposity in children with high cortisol awakening patterns (β = 0.204; p = .020) and high sweet food consumption (β = 0.190; p = .031), whereas stress was associated with lower adiposity in the most active children (β = -0.163; p = .022). Stress is associated with the development of children's adiposity, but the effects depend on cortisol levels and life-style factors. This creates new perspectives for multifactorial obesity prevention programs. Our results also highlight the adverse effect of an unhealthy body composition on children's psychological well-being.

Polymer/Layered Silicate Nano composites

International Nuclear Information System (INIS)

Bakhit, M.E.E.H.

2012-01-01

Polymer–clay nano composites have attracted the attention of many researchers and experimental results are presented in a large number of recent papers and patents because of the outstanding mechanical properties and low gas permeabilities that are achieved in many cases. Polymer-clay nano composites are a new class of mineral-field polymer that contain relatively small amounts (<10%) of nanometer-sized clay particles. Polymer/clay nano composites have their origin in the pioneering research conducted at Toyota Central Research Laboratories and the first historical record goes back to 1987. The matrix was nylon-6 and the filler MMT. Because of its many advantages such as high mechanical properties, good gas barrier, flame retardation, etc. polymer/clay nano composites have been intensely investigated and is currently the subject of many research programs. Nano composite materials are commercially important and several types of products with different shapes and applications including food packaging films and containers, engine parts, dental materials, etc. are now available in markets. A number of synthesis routes have been developed in the recent years to prepare these materials, which include intercalation of polymers or prepolymers from solution, in-situ polymerization, melt intercalation etc. In this study, new nano composite materials were produced from the components of rubber (Nbr, SBR and EPDM) as the polymeric matrix and organically modified quaternary alkylammonium montmorillonite in different contents (3, 5, 7, and 10 phr) as the filler by using an extruder then, the rubber nano composite sheets were irradiated at a dose of 0, 50, 75, 100 and 150 KGy using Electron beam Irradiation technique as a crosslinking agent. These new materials can be characterized by using various analytical techniques including X-ray diffractometer XRD, Thermogravimetric analyzer TGA, scanning electron microscope (SEM), transmission electron microscope (TEM),Fourier transform

Experimental Study of the Hygrothermal Effect on Wear Behavior of Composite Materials

Directory of Open Access Journals (Sweden)

Fadhel Abbas. Abdulla

2017-07-01

Full Text Available The hygrothermal effect on the wear behavior of composite material (fiberglass and polyester resin vf=40% was investigated experimentally in this work. The study includes manufacturing of test device (pin on disc according to ASTM G 99. In order to study the hygrothermal effect on wear behavior of composite materials the hygrothermal chamber was manufactured. The experimental results show that the wear of glass fiber/polyester increased with increasing the load, sliding speed and sliding distance. The load and sliding distance were more effective on the wear of the composite rather than sliding speed. Also, it has been revealed that, the hygrothermal is considerable effect that, the wear rate of glass fiber/polyester without hygrothermal effect is lower than wear with hygrothermal effect. Applied load is the wear factor that has the highest physical influence on the wear of composites materials than other wear factors. Also, the wear of glass fiber/polyester without hygrothermal effect is lower than wear with hygrothermal effect.

Ballistic performance of a Kevlar-29 woven fibre composite under varied temperatures

Science.gov (United States)

Soykasap, O.; Colakoglu, M.

2010-05-01

Armours are usually manufactured from polymer matrix composites and used for both military and non-military purposes in different seasons, climates, and regions. The mechanical properties of the composites depend on temperature, which also affects their ballistic characteristics. The armour is used to absorb the kinetic energy of a projectile without any major injury to a person. Therefore, besides a high strength and lightness, a high damping capacity is required to absorb the impact energy transferred by the projectile. The ballistic properties of a Kevlar 29/polyvinyl butyral composite are investigated under varied temperatures in this study. The elastic modulus of the composite is determined from the natural frequency of composite specimens at different temperatures by using a damping monitoring method. Then, the backside deformation of composite plates is analysed experimentally and numerically employing the finite-element program Abaqus. The experimental and numeric results obtained are in good agreement.

Study on Fatigue Performance of Composite Bolted Joints with Bolt-Hole Delamination

Science.gov (United States)

Liu, M. J.; Yu, S.; Zhao, Q. Y.

2018-03-01

Fatigue performance of composite structure with imperfections is a challenging subject at present. Based on cohesive zone method and multi-continuum theory, delamination evolution response and fatigue life prediction of a 3D composite single-lap joint with a bolt-hole have been investigated through computer codes Abaqus and Fe-safe. Results from the comparison of a perfect composite bolted joint with another defect one indicates that a relatively small delamination damage around the bolt hole brings about significant degradation of local material performance. More notably, fatigue life of stress concentration region of composite bolted joints is highly sensitive to external loads, as an increase of 67% cyclic load amplitude leads to an decrease of 99.5% local fatigue life in this study. However, the numerical strategy for solving composite fatigue problems is meaningful to engineering works.

A study on the crushing behavior of basalt fiber reinforced composite structures

Science.gov (United States)

Pandian, A.; Veerasimman, A. P.; Vairavan, M.; Francisco, C.; Sultan, M. T. H.

2016-10-01

The crushing behavior and energy absorption capacity of basalt fiber reinforced hollow square structure composites are studied under axial compression. Using the hand layup technique, basalt fiber reinforced composites were fabricated using general purpose (GP) polyester resin with the help of wooden square shaped mould of varying height (100 mm, 150 mm and 200 mm). For comparison, similar specimens of glass fiber reinforced polymer composites were also fabricated and tested. Axial compression load is applied over the top end of the specimen with cross head speed as 2 mm/min using Universal Testing Machine (UTM). From the experimental results, the load-deformation characteristics of both glass fiber and basalt fiber composites were investigated. Crashworthiness and mode of collapse for the composites were determined from load-deformation curve, and they were then compared to each other in terms of their crushing behaviors.

The Underdog Disciplines: Comics Studies and Composition and Rhetoric

Science.gov (United States)

Kirtley, Susan

2015-01-01

This report discusses the answer to the question: What might comic studies learn from the slightly older field of composition and rhetoric? The author asks the question as a member of both fields. It is clear that both disciplines struggle for legitimacy within the academy. While comics studies strives for respectability given the popular nature…

Study of dielectric and piezoelectric properties of CNT reinforced PZT-PVA 0-3 composite

Science.gov (United States)

Vyas, Prince; Prajapat, Rampratap; Manmeeta, Saxena, Dhiraj

2016-05-01

Ferroelectric ceramic/polymer composites have the compliance of polymers which overcome the problems of brittleness in ceramics. By imbedding piezoelectric ceramic powder into a polymer matrix, 0-3 composites with good mechanical properties and high dielectric breakdown strength can be developed. The obtained composites of 0-3 connectivity exhibit the piezoelectric properties of ceramics and flexibility, strength and lightness of polymer. These composites can be used in vibration sensing and transducer applications specially as piezoelectric sensors. A potential way to improve piezoelectric& dielectric properties of theses composites is by inclusion of another conductive phase in these composites as reported in the literature. In present work, we prepared PZT-PVA 0-3 composites with 60% ceramic volume fraction reinforced with CNTs with volume ranging from 0 to 1.5 vol%. These CNT reinforced composites were obtained using hot press method with thickness of 200 µm having 0-3 conductivity. These composites were poled applying DC voltage. Dielectric properties of these samples were obtained in a wide frequency range (100 Hz to 1 Mhz) at room temperature. The piezoelectric properties of these composites were analyzed by measuring piezoelectric charge constants (d33). The dielectric and piezoelectric properties of these composites were studied as a function of CNT volume content. In these reinforced composites, CNTs act as a conductive filler dispersed in the matrix which in turn facilitates poling and results in an increase of the piezoelectric properties of the composite due to formation of percolation path through the composites. With a CNT content of 0.3 vol.% in PZT/PVA/CNTs, an increase of 61.3 % was observed in piezoelectric strain factors (d33). In these CNT reinforced composites, a substantial increase (approx. 67%) was also observed in dielectric constant and approximately 89% increase was observed in dielectric loss factor. Results so obtained are in the good

A study of breast composition using radiographic techniques

International Nuclear Information System (INIS)

Noriah Jamal

2005-01-01

Accurate knowledge of breast composition is fundamental to the diagnosis and treatment of breast diseases. The goal of the research described in this thesis is to develop a system of experimental methods and theoretical models for studying breast composition using radiographic techniques. This research is divided into three parts. In part one, a technique based on the decomposition of breast components was developed and validated under laboratory conditions through the measurement of mastectomy specimen composition. The technique used double-exposure dual energy subtraction microradiography in conjunction with computed radiography in a five steps sequence, namely; a specimen was exposed at low and high energies alternately, followed by image registration, image subtraction and subsequent analysis of the subtracted image. The technique was then applied to quantify composition of mastectomy specimens. In part two, a quantitative assessment technique of breast density developed using MATLAB based image processing of digital mammograms. A comparison of breast density, classified by computer and subjective evaluation based on Tabar's patterns, was carried out. Inter-observer variations were analysed. In part three, a technique to estimate breast glandularity using phantom attenuation was developed and was used to estimate breast density for a large population sample. The difference in breast glandularity between three ethnic groups was tested for significance using the nonparametric Kruskal-Wallis test. This part also included an assessment of mammographic mean glandular dose using phantom-based and patient-based methods. Results from part 1 showed that in the double-exposure dual energy microradiography, the resulting fibroglandular tissue area was in 90.3 % agreement with the corresponding manually delineated areas by radiologists. In part 2 the results of computerised assessment of breast density from digitised mammograms correlated well (r 2 =0.92) with the

Study of filling material of dental composites. An analytical approach using radio-activation

Energy Technology Data Exchange (ETDEWEB)

Eke, Canel [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Akdeniz Univ., Antalya (Turkey). Div. of Physics Education; Er, Kursat [Akdeniz Univ., Antalya (Turkey). Dept. of Endodontics; Segebade, Christian [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Boztosun, Ismail [Akdeniz Univ., Antalya (Turkey). Nuclear Sciences Application and Research Center; Akdeniz Univ., Antalya (Turkey). Dept. of Physics

2018-04-01

The aim of this study is to carry out elemental analyses of dental composites acquired from different producers using photoactivation analysis (PAA). High energy electrons produced by an electron linear accelerator are absorbed by a tungsten disk (Bremsstrahlung converter) thereby producing high energy X-rays (bremsstrahlung). The dental composite materials under study were exposed to the bremsstrahlung radiation whereby radionuclides were produced through photonuclear reactions. Their radioactivities were measured using high resolution semiconductor spectrometers equipped with high purity germanium detectors (HPGe). The spectra were analysed using appropriate computer software. As a result, photonuclear reactions of 12 stable elements were detected in different dental composite species, and the elemental concentrations were calculated. For comparison, the dental composites were also investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray fluorescence spectrometry (EDXRF). Various sizes and shapes of dental composites were observed using SEM. However, contents of dental composites, e.g. Mg, Ni, Ba and Sr were obtained by PAA whilst C, O, Al, S, Ba and Sr were detected by EDXRF spectrometry. The results for Ba and Sr obtained using the two techniques show considerable difference.

Semiconductor laser joint study program with Rome Laboratory

Science.gov (United States)

Schaff, William J.; Okeefe, Sean S.; Eastman, Lester F.

1994-09-01

A program to jointly study vertical-cavity surface emitting lasers (VCSEL) for high speed vertical optical interconnects (VOI) has been conducted under an ES&E between Rome Laboratory and Cornell University. Lasers were designed, grown, and fabricated at Cornell University. A VCSEL measurement laboratory has been designed, built, and utilized at Rome Laboratory. High quality VCSEL material was grown and characterized by fabricating conventional lateral cavity lasers that emitted at the design wavelength of 1.04 microns. The VCSEL's emit at 1.06 microns. Threshold currents of 16 mA at 4.8 volts were obtained for 30 microns diameter devices. Output powers of 5 mW were measured. This is 500 times higher power than from the light emitting diodes employed previously for vertical optical interconnects. A new form of compositional grading using a cosinusoidal function has been developed and is very successful for reducing diode series resistance for high speed interconnection applications. A flip-chip diamond package compatible with high speed operation of 16 VCSEL elements has been designed and characterized. A flip-chip device binding effort at Rome Laboratory was also designed and initiated. This report presents details of the one-year effort, including process recipes and results.

Estimation of physical properties of laminated composites via the method of inverse vibration problem

Energy Technology Data Exchange (ETDEWEB)

Balci, Murat [Dept. of Mechanical Engineering, Bayburt University, Bayburt (Turkmenistan); Gundogdu, Omer [Dept. of Mechanical Engineering, Ataturk University, Erzurum (Turkmenistan)

2017-01-15

In this study, estimation of some physical properties of a laminated composite plate was conducted via the inverse vibration problem. Laminated composite plate was modelled and simulated to obtain vibration responses for different length-to-thickness ratio in ANSYS. Furthermore, a numerical finite element model was developed for the laminated composite utilizing the Kirchhoff plate theory and programmed in MATLAB for simulations. Optimizing the difference between these two vibration responses, inverse vibration problem was solved to obtain some of the physical properties of the laminated composite using genetic algorithms. The estimated parameters are compared with the theoretical results, and a very good correspondence was observed.

Estimation of physical properties of laminated composites via the method of inverse vibration problem

International Nuclear Information System (INIS)

Balci, Murat; Gundogdu, Omer

2017-01-01

In this study, estimation of some physical properties of a laminated composite plate was conducted via the inverse vibration problem. Laminated composite plate was modelled and simulated to obtain vibration responses for different length-to-thickness ratio in ANSYS. Furthermore, a numerical finite element model was developed for the laminated composite utilizing the Kirchhoff plate theory and programmed in MATLAB for simulations. Optimizing the difference between these two vibration responses, inverse vibration problem was solved to obtain some of the physical properties of the laminated composite using genetic algorithms. The estimated parameters are compared with the theoretical results, and a very good correspondence was observed

A study on effect of ATH on Euphorbia coagulum modified polyester banana fiber composite

Science.gov (United States)

Kumari, Sanju; Rai, Bhuvneshwar; Kumar, Gulshan

2018-02-01

Fiber reinforced polymer composites are used for building and structural applications due to their high strength. In conventional composites both the binder and the reinforcing fibers are synthetic or either one of the material is natural. In the present study coagulum of Euphorbia royleana has been used for replacing polyester resinas binder in polyester banana composite. Euphorbia coagulum (driedlatex) is rich in resinous mass (60-80%), which are terpenes and polyisoprene (10-20%). Effect of varying percentage of coagulum content on various physico-mechanical properties of polyester-banana composites has been studied. Since banana fiber is sensitive to water due to presence of polar group, banana composite undergoes delamination and deterioration under humid condition. Alkali treated banana fiber along with coagulum content has improved overall mechanical properties and reduction in water absorption. The best physico-mechanical properties have been achieved on replacing 40% of polyester resin by coagulum. An increase of 50% in bending strength, 30% bending modulus and 45% impact strength as well as 68% decrease in water absorption was observed. Incorporation of 20% ATH as flame retardant in coagulum modified banana polyester composite enhanced limiting oxygen index from 20.6 to 26.8% and smoke density reduced up to 40%. This study presents the possibility of utilization of renewable materials for environmental friendly composite development as well as to find out alternative feedstock for petroleum products. Developed Euphorbia latex modified banana polyester composites can have potential utility in hardboard, partition panel, plywood and automotive etc.

Vertical circulation and thermospheric composition: a modelling study

Directory of Open Access Journals (Sweden)

H. Rishbeth

1999-06-01

Full Text Available The coupled thermosphere-ionosphere-plasmasphere model CTIP is used to study the global three-dimensional circulation and its effect on neutral composition in the midlatitude F-layer. At equinox, the vertical air motion is basically up by day, down by night, and the atomic oxygen/molecular nitrogen [O/N2] concentration ratio is symmetrical about the equator. At solstice there is a summer-to-winter flow of air, with downwelling at subauroral latitudes in winter that produces regions of large [O/N2] ratio. Because the thermospheric circulation is influenced by the high-latitude energy inputs, which are related to the geometry of the Earth's magnetic field, the latitude of the downwelling regions varies with longitude. The downwelling regions give rise to large F2-layer electron densities when they are sunlit, but not when they are in darkness, with implications for the distribution of seasonal and semiannual variations of the F2-layer. It is also found that the vertical distributions of O and N2 may depart appreciably from diffusive equilibrium at heights up to about 160 km, especially in the summer hemisphere where there is strong upwelling. Atmospheric composition and structure (thermosphere · composition and chemistry · Ionosphere (ionosphere · atmosphere interactions

Thermoviscoelastic characterization and prediction of Kevlar/epoxy composite laminates

Science.gov (United States)

Gramoll, K. C.; Dillard, D. A.; Brinson, H. F.

1990-01-01

The thermoviscoelastic characterization of Kevlar 49/Fiberite 7714A epoxy composite lamina and the development of a numerical procedure to predict the viscoelastic response of any general laminate constructed from the same material were studied. The four orthotropic material properties, S sub 11, S sub 12, S sub 22, and S sub 66, were characterized by 20 minute static creep tests on unidirectional (0) sub 8, (10) sub 8, and (90) sub 16 lamina specimens. The Time-Temperature Superposition-Principle (TTSP) was used successfully to accelerate the characterization process. A nonlinear constitutive model was developed to describe the stress dependent viscoelastic response for each of the material properties. A numerical procedure to predict long term laminate properties from lamina properties (obtained experimentally) was developed. Numerical instabilities and time constraints associated with viscoelastic numerical techniques were discussed and solved. The numerical procedure was incorporated into a user friendly microcomputer program called Viscoelastic Composite Analysis Program (VCAP), which is available for IBM PC type computers. The program was designed for ease of use. The final phase involved testing actual laminates constructed from the characterized material, Kevlar/epoxy, at various temperatures and load level for 4 to 5 weeks. These results were compared with the VCAP program predictions to verify the testing procedure and to check the numerical procedure used in the program. The actual tests and predictions agreed for all test cases which included 1, 2, 3, and 4 fiber direction laminates.

HYDRAULIC CONCRETE COMPOSITION AND PROPERTIES CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

O. M. Pshinko

2015-08-01

Full Text Available Purpose. Scientific work aims at the development and testing of information system to meet the challenges of concrete composition design and control (for railway structures and buildings based on the physico-analytical method algorithm for hydraulic concrete composition calculation. Methodology. The proposed algorithm of hydraulic concrete composition calculation is based on the physicochemical mechanics and in particular on the rheology of elastic–viscous–plastic bodies. The system of canonical equations consists of the equations for concrete strength, absolute volume, concrete mix consistency as well as the equation for optimal concrete saturation with aggregates while minimizing cement content. The joint solution of these four equations related to composition allows determining for the materials the concrete composition of required strength, concrete workability with minimum cement content. The procedure for calculation of hydraulic concrete composition according to the physico-analytical method consists of two parts: 1 physical, which is laboratory testing of concrete mix components in different concrete compositions; 2 analytical, which represents the calculation algorithm for concrete compositions equivalent in concrete strength and workability that comply with the specific conditions of concrete placing. Findings. To solve the problem of designing the concrete composition with the desired properties for railway structures and buildings it was proposed to use the information technology in the form of a developed computer program whose algorithm includes the physico-analytical method for hydraulic concrete composition determination. Originality. The developed concrete composition design method takes into account the basic properties of raw materials, concrete mix and concrete, which are pre-determined. The distinctive feature of physico-analytical method is obtaining of a set of equivalent compositions with a certain concrete mix

Adaptive, Active and Multifunctional Composite and Hybrid Materials Program: Composite and Hybrid Materials ERA

Science.gov (United States)

2014-04-01

590 . SMASIS2011-4934. L. D. Peel, J. Baur, D. Phillips, and A. McClung, “The Effect of Scaling on the Performance of Elastomer Composite Actuators...fragility of the fibers it was also not possible to extract some of them from their adhesive paper mountings without breakage. For Raman ... Raman spectroscopy and microscopy (SEM), the nanocomposites were evaluated for their thermal analytical properties using TGA. Electrical

Defluoridation using biomimetically synthesized nano zirconium chitosan composite: Kinetic and equilibrium studies

International Nuclear Information System (INIS)

Prasad, Kumar Suranjit; Amin, Yesha; Selvaraj, Kaliaperumal

2014-01-01

Highlights: • Colloidal Zr nanoparticles, synthesized using Aloe vera extract were entrapped in chitosan beads. • Zr loaded beads were employed for removal of F − ion and showed excellent removal efficiency. • Zr and chitosan are cost effective materials hence can be a good adsorbent for removal of fluoride. - Abstract: The present study reports a novel approach for synthesis of Zr nanoparticles using aqueous extract of Aloe vera. Resulting nanoparticles were embedded into chitosan biopolymer and termed as CNZr composite. The composite was subjected to detailed adsorption studies for removal of fluoride from aqueous solution. The synthesized Zr nanoparticles showed UV–vis absorption peak at 420 nm. TEM result showed the formation of polydispersed, nanoparticles ranging from 18 nm to 42 nm. SAED and XRD analysis suggested an fcc (face centered cubic) Zr crystallites. EDAX analysis suggested that Zr was an integral component of synthesized nanoparticles. FT-IR study indicated that functional group like -NH, -C=O, -C=N and -C=C were involved in particle formation. The adsorption of fluoride on to CNZr composite worked well at pH 7.0, where ∼99% of fluoride was found to be adsorbed on adsorbent. Langmuir isotherm model best fitted the equilibrium data since it presented higher R 2 value than Freundlich model. In comparison to pseudo-first order kinetic model, the pseudo-second order model could explain adsorption kinetic behavior of F − onto CNZr composite satisfactorily with a good correlation coefficient. The present study revealed that CNZr composite may work as an effective tool for removal of fluoride from contaminated water

Studies on the proximate composition, functional properties and ...

African Journals Online (AJOL)

The present study produced full fat and defatted flours from matured ackee apple arils and evaluated the proximate composition and the effect of pH and salt concentrations on some of the functional properties of the full fat flour and the defatted flour. Matured ackee apple arils were oven-dried at 60 oC and milled to obtain ...

Compositional Safety Analysis using Barrier Certificates

DEFF Research Database (Denmark)

Sloth, Christoffer; Pappas, George J.; Wisniewski, Rafael

2012-01-01

This paper proposes a compositional method for verifying the safety of a dynamical system, given as an interconnection of subsystems. The safety verification is conducted by the use of the barrier certificate method; hence, the contribution of this paper is to show how to obtain compositional...... conditions for safety verification. We show how to formulate the verification problem, as a composition of coupled subproblems, each given for one subsystem. Furthermore, we show how to find the compositional barrier certificates via linear and sum of squares programming problems. The proposed method makes...... it possible to verify the safety of higher dimensional systems, than the method for centrally computed barrier certificates. This is demonstrated by verifying the safety of an emergency shutdown of a wind turbine....

Second generation PMR polyimide/fiber composites

Science.gov (United States)

Cavano, P. J.

1979-01-01

A second generation polymerization monomeric reactants (PMR) polyimdes matrix system (PMR 2) was characterized in both neat resin and composite form with two different graphite fiber reinforcements. Three different formulated molecular weight levels of laboratory prepared PMR 2 were examined, in addition to a purchased experimental fully formulated PMR 2 precurser solution. Isothermal aging of graphite fibers, neat resin samples and composite specimens in air at 316 C were investigated. Humidity exposures at 65 C and 97 percent relative humidity were conducted for both neat resin and composites for eight day periods. Anaerobic char of neat resin and fire testing of composites were conducted with PMR 15, PMR 2, and an epoxy system. Composites were fire tested on a burner rig developed for this program. Results indicate that neat PMR 2 resins exhibit excellent isothermal resistance and that PMR 2 composite properties appear to be influenced by the thermo-oxidative stability of the reinforcing fiber.

Sorption of radiocesium by composites of variable composition

International Nuclear Information System (INIS)

Someda, H.H.; El-zahhar, A.A.; Shehata, M.K.K.; El-Naggar, H.A.

2000-01-01

Cellulose and different natural materials - supported hexacyanoferrate composites were prepared and characterized by IR and x-ray diffraction studies. The stability of the prepared composites towards concentrated mineral acids was studied. The capacity of such prepared composites towards the uptake of cesium was calculated and found to be 1.5-1.7 meq/g. The capacity of the natural materials - supported composites was found to be slightly higher than that of the cellulose supported one. Different parameters affecting the sorption process of the radioelement such as acid concentration, Ph variation, competing ions and carrier concentration were studied. The release of the cesium traces from the composite materials was studied under different HCl concentrations and it was found that there is no release of the absorbed cesium up to 2.5 M even for long contact time up to two weeks. The work is under developing and extension

Composition at Washington State University: Building a Multimodal Bricolage

Science.gov (United States)

Ericsson, Patricia; Hunter, Leeann Downing; Macklin, Tialitha Michelle; Edwards, Elizabeth Sue

2016-01-01

Multimodal pedagogy is increasingly accepted among composition scholars. However, putting such pedagogy into practice presents significant challenges. In this profile of Washington State University's first-year composition program, we suggest a multi-vocal and multi-theoretical approach to addressing the challenges of multimodal pedagogy. Patricia…

The effect of composition on volatility from a copper alloy

International Nuclear Information System (INIS)

McCarthy, K.A.; Smolik, G.R.; Wallace, R.S.

1994-01-01

During a Loss of Coolant Accident (LOCA) activated structural material can be mobilized through oxidation. Information on how much material is mobilized in an accident is necessary for performing safety assessments of fusion reactor designs. The Fusion Safety Program at the Idaho National Engineering Laboratory has an experimental program to measure mobilized mass as a function of temperature for various oxidizing environments. Materials studied have included beryllium (important because of its toxicity), copper alloys, a niobium alloy, PCA and HT-9 steel, tungsten (pure and an alloy), and a vanadium alloy. Some materials undergo a significant change in composition during irradiation. An example of this is copper (a candidate for the ITER first wall, divertor substrate, and various instrumentation probes and antennas), which can have as much as 1 wt% zinc due to transmutation. Additionally, as the design for ITER evolves, a slightly different copper alloy may be selected. Compositional changes may affect the extent that various elements are volatilized due to such mechanisms as diffusion through the alloy, and penetration and release from oxide layers formed on the material. To accurately calculate offsite doses for various irradiation scenarios, one must understand the effect of composition on volatility

Preliminary study on the development of EFB Fibre-sago starch composites: impact and flexural properties

International Nuclear Information System (INIS)

Nor Hasimah Mohamed; Khairul Zaman Mohd Dahlan

2004-01-01

There is growing interest in the use of natural fibres as the reinforcements for polymer composites in the automotive industry and as matrix for composites in building products application to replace synthetic fibres. In this respect the aim of this study is to develop an environmental friendly composites for furniture industry based on EFB fibres and sago starch. In this preliminary study, a basic composition and processing of EFB fibres-sago starch composites were established and the properties of the composites were determined. EFB fibre content was varied between 50-80% by weight. The amount of sago starch in liquid form was also varied and final weight percentage of sago starch added into the EFB fibres was adjusted accordingly. The mixtures of EFB fibres and sago starch were blended using Haake Rheomixer. The preliminary results indicate that the impact and flexural strengths increased up to 33.58 J/m 2 and 18.92 Mpa, respectively at 70% fibres contents. Further study is now being conducted to improve the processability of the composites by adding plasticisers and processing aids and to incorporate certain reactive additives that can enhance electron beam cross linking for further improvement on the mechanical properties of the composites. (Author)

Critical joints in large composite aircraft structure

Science.gov (United States)

Nelson, W. D.; Bunin, B. L.; Hart-Smith, L. J.

1983-01-01

A program was conducted at Douglas Aircraft Company to develop the technology for critical structural joints of composite wing structure that meets design requirements for a 1990 commercial transport aircraft. The prime objective of the program was to demonstrate the ability to reliably predict the strength of large bolted composite joints. Ancillary testing of 180 specimens generated data on strength and load-deflection characteristics which provided input to the joint analysis. Load-sharing between fasteners in multirow bolted joints was computed by the nonlinear analysis program A4EJ. This program was used to predict strengths of 20 additional large subcomponents representing strips from a wing root chordwise splice. In most cases, the predictions were accurate to within a few percent of the test results. In some cases, the observed mode of failure was different than anticipated. The highlight of the subcomponent testing was the consistent ability to achieve gross-section failure strains close to 0.005. That represents a considerable improvement over the state of the art.

Principal variance component analysis of crop composition data: a case study on herbicide-tolerant cotton.

Science.gov (United States)

Harrison, Jay M; Howard, Delia; Malven, Marianne; Halls, Steven C; Culler, Angela H; Harrigan, George G; Wolfinger, Russell D

2013-07-03

Compositional studies on genetically modified (GM) and non-GM crops have consistently demonstrated that their respective levels of key nutrients and antinutrients are remarkably similar and that other factors such as germplasm and environment contribute more to compositional variability than transgenic breeding. We propose that graphical and statistical approaches that can provide meaningful evaluations of the relative impact of different factors to compositional variability may offer advantages over traditional frequentist testing. A case study on the novel application of principal variance component analysis (PVCA) in a compositional assessment of herbicide-tolerant GM cotton is presented. Results of the traditional analysis of variance approach confirmed the compositional equivalence of the GM and non-GM cotton. The multivariate approach of PVCA provided further information on the impact of location and germplasm on compositional variability relative to GM.

Recommendations for composite manufacturing pultrusion process and equipment

Science.gov (United States)

Steiner, R. L.; Cole, J. D.; Strong, A. B.; Todd, R. H.

1992-10-01

Pultrusion is an important composite manufacturing process that holds great potential for reducing the cost of composite parts. However, pultrusion machine manufacturers and those using this continuous process have generally worked in relative isolation from each other and have, therefore, repeated many of the same errors. This paper reports the findings of a research program involving input from 15 pultruder manufacturers who have contributed non-proprietary information for the "best" design for the pultrusion machine. Key areas of design difficulty have been identified and some suggested remedies given. The results of this program will be used to construct a "state-of-the-art" pultrusion machine in the authors' laboratory. The initial findings provided input for a Quality Function Deployment (QFD) study which is basis for the functional specification for the pultrusion machine. By using QFD, capabilities of existing machines were determined and design requirements for an improved state-of-the-art machine were established. The QFD exercise provided an in-depth look at the relationship between desired machine capabilities and machine design requirements.

An experimental study of mechanical behavior of natural fiber reinforced polymer matrix composites

Science.gov (United States)

Ratna, Sanatan; Misra, Sheelam

2018-05-01

Fibre-reinforced polymer composites have played a dominant role for a long time in a variety of applications for their high specific strength and modulus. The fibre which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only synthetic fibres such as glass, carbon etc., have been used in fibre reinforced plastics. Although glass and other synthetic fibre-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of horse hair, an animal fibre abundantly available in India. Animal fibres are not only strong and lightweight but also relatively very cheaper than mineral fibre. The present work describes the development and characterization of a new set of animal fiber based polymer composites consisting of horse hair as reinforcement and epoxy resin. The newly developed composites are characterized with respect to their mechanical characteristics. Experiments are carried out to study the effect of fibre length on mechanical behavior of these epoxy based polymer composites. Composite made form horse hair can be used as a potential reinforcing material for many structural and non-structural applications. This work can be further extended to study other aspects of such composites like effect of fiber content, loading pattern, fibre treatment on mechanical behavior of horse hair based polymer horse hair.

Composite Materials: An Educational Need.

Science.gov (United States)

Saliba, Tony E.; Snide, James A.

1990-01-01

Described is the need to incorporate the concepts and applications of advanced composite materials into existing chemical engineering programs. Discussed are the justification for, and implementation of topics including transport phenomena, kinetics and reactor design, unit operations, and product and process design. (CW)

A correlation study of proximate composition, physical and cooking properties of new high yielding and disease resistant rice varieties

Directory of Open Access Journals (Sweden)

Nuzhat Rasool

2015-12-01

Full Text Available The present study was aimed to compare proximate composition, physical, and cooking properties of locally cultivated rice varieties of Kashmir division viz.; SR-1, K-448, and K-39. Various physiochemical properties were studied. The relationship between physical, proximate composition, and cooking properties was determined using Pearson’s correlation. Length–breadth (L/B ratio showed a significant positive correlation with kernel length and negative correlation with thousand kernel weight, with a correlation coefficient (r of 0.893 and −0.855, respectively, (p  0.05. Solid loss in gruel was observed to have a negative correlation with L/B ratio (r = −0.432, p > 0.05, water uptake ratio (r = −0.742, p < 0.05, and cooking time (r = −0.678, p < 0.05. The rice cultivars with higher cooking time showed lower gruel solid loss and vice versa. Water uptake was observed to be positively correlated with L/B ratio (r = 0.768, p < 0.05. Among all the cultivars studied, K-448 variety has potential for consumers’ preference and it could be used for breeding programs for the improvement of valuable grain quality traits.

Salivary Secretion and Composition in Malaria: A Case-control Study

African Journals Online (AJOL)

Summary: No previous studies have documented changes in salivary secretion in patients with malaria. This study aimed to compare salivary secretion and composition in malaria positive and malaria negative individuals. Ninety participants composed of 40 malaria parasite positive and 50 malaria parasite negative ...

Experimental Study of the Hygrothermal Effect on Wear Behavior of Composite Materials

OpenAIRE

Fadhel Abbas. Abdulla; Katea L. Hamid

2017-01-01

The hygrothermal effect on the wear behavior of composite material (fiberglass and polyester resin vf=40%) was investigated experimentally in this work. The study includes manufacturing of test device (pin on disc) according to ASTM G 99. In order to study the hygrothermal effect on wear behavior of composite materials the hygrothermal chamber was manufactured. The experimental results show that the wear of glass fiber/polyester increased with increasing the load, sliding speed and sliding di...

Member Perceptions of Informal Science Institution Graduate Certificate Program: Case Study of a Community of Practice

Science.gov (United States)

Ball, Lois A.

This research attempted to understand the experiences of a cohort of informal and formal science educators and informal science institution (ISI) community representatives during and after completion of a pilot graduate certificate program. Informal science educators (ISEs) find limited opportunities for professional development and support which influence their contributions to America's science literacy and school science education. This emergent design nested case study described how an innovative program provided professional development and enabled growth in participants' abilities to contribute to science literacy. Data were collected through interviews, participant observations, and class artifacts. The program by design and constituency was the overarching entity that accounted for members' experiences. Three principal aspects of the ISI certificate program and cohort which influenced perceptions and reported positive outcomes were (1) the cohort's composition and their collaborative activities which established a vigorous community of practice and fostered community building, mentoring, and networking, (2) long term program design and implementation which promoted experiential learning in a generative classroom, and (3) ability of some members who were able to be independent or autonomous learners to embrace science education reform strategies for greater self-efficacy and career advancement. This research extends the limited literature base for professional development of informal science educators and may benefit informal science institutions, informal and formal science educators, science education reform efforts, and public education and science-technology-society understanding. The study may raise awareness of the need to establish more professional development opportunities for ISEs and to fund professional development. Further, recognizing and appreciating informal science educators as a diverse committed community of professionals who positively

Composite likelihood and two-stage estimation in family studies

DEFF Research Database (Denmark)

Andersen, Elisabeth Anne Wreford

2004-01-01

In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models are d...

SISTEM PENDUKUNG KEPUTUSAN UNTUK MENGEVALUASI INTERNAL PROGRAM STUDI

Directory of Open Access Journals (Sweden)

Indhitya Rahman Padiku

2016-04-01

Full Text Available The development of major and study program cannot be separated by some internal factors weather directly influenced number of new registration students or indirectly. It needs a method to both know and to analyze internal evaluation variables in major or study program. Naive Bayes Clasifier (NBC method is the simple form of Bayesian network that assume all features are independent each other. NBC shows us a great performance entirely in accuracy and error level classification. NBC is able to differentiate irrelevance attribute and also classified some attributes in prediction needs. This research hopefully can be useful for major internal evaluating and study program in order to increase the number of new registration students. The classification by influenced of variables to evaluate the condition of both major and study program for the new registration students.

Defluoridation using biomimetically synthesized nano zirconium chitosan composite: Kinetic and equilibrium studies

Energy Technology Data Exchange (ETDEWEB)

Prasad, Kumar Suranjit, E-mail: suranjit@gmail.com [Department of Environmental Biotechnology, Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences (ARIBAS), New Vallabh Vidyanagar, Anand, 388121 Gujarat (India); Amin, Yesha, E-mail: yesha_2879@yahoo.co.in [Department of Environmental Biotechnology, Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences (ARIBAS), New Vallabh Vidyanagar, Anand, 388121 Gujarat (India); Selvaraj, Kaliaperumal, E-mail: k.selvaraj@ncl.res.in [Nano and Computational Materials Lab, Catalysis Division, National Chemical Laboratory, Council of Scientific and Industrial Research, Pune 411008 (India)

2014-07-15

Highlights: • Colloidal Zr nanoparticles, synthesized using Aloe vera extract were entrapped in chitosan beads. • Zr loaded beads were employed for removal of F{sup −} ion and showed excellent removal efficiency. • Zr and chitosan are cost effective materials hence can be a good adsorbent for removal of fluoride. - Abstract: The present study reports a novel approach for synthesis of Zr nanoparticles using aqueous extract of Aloe vera. Resulting nanoparticles were embedded into chitosan biopolymer and termed as CNZr composite. The composite was subjected to detailed adsorption studies for removal of fluoride from aqueous solution. The synthesized Zr nanoparticles showed UV–vis absorption peak at 420 nm. TEM result showed the formation of polydispersed, nanoparticles ranging from 18 nm to 42 nm. SAED and XRD analysis suggested an fcc (face centered cubic) Zr crystallites. EDAX analysis suggested that Zr was an integral component of synthesized nanoparticles. FT-IR study indicated that functional group like -NH, -C=O, -C=N and -C=C were involved in particle formation. The adsorption of fluoride on to CNZr composite worked well at pH 7.0, where ∼99% of fluoride was found to be adsorbed on adsorbent. Langmuir isotherm model best fitted the equilibrium data since it presented higher R{sup 2} value than Freundlich model. In comparison to pseudo-first order kinetic model, the pseudo-second order model could explain adsorption kinetic behavior of F{sup −} onto CNZr composite satisfactorily with a good correlation coefficient. The present study revealed that CNZr composite may work as an effective tool for removal of fluoride from contaminated water.

A model for the design and programming of multi-cores

NARCIS (Netherlands)

Jesshope, C.; Grandinetti, L.

2008-01-01

This paper describes a machine/programming model for the era of multi-core chips. It is derived from the sequential model but replaces sequential composition with concurrent composition at all levels in the program except at the level where the compiler is able to make deterministic decisions on

Medicare Program; Prospective Payment System and Consolidated Billing for Skilled Nursing Facilities for FY 2018, SNF Value-Based Purchasing Program, SNF Quality Reporting Program, Survey Team Composition, and Correction of the Performance Period for the NHSN HCP Influenza Vaccination Immunization Reporting

Science.gov (United States)

2017-08-04

This final rule updates the payment rates used under the prospective payment system (PPS) for skilled nursing facilities (SNFs) for fiscal year (FY) 2018. It also revises and rebases the market basket index by updating the base year from 2010 to 2014, and by adding a new cost category for Installation, Maintenance, and Repair Services. The rule also finalizes revisions to the SNF Quality Reporting Program (QRP), including measure and standardized resident assessment data policies and policies related to public display. In addition, it finalizes policies for the Skilled Nursing Facility Value-Based Purchasing Program that will affect Medicare payment to SNFs beginning in FY 2019. The final rule also clarifies the regulatory requirements for team composition for surveys conducted for investigating a complaint and aligns regulatory provisions for investigation of complaints with the statutory requirements. The final rule also finalizes the performance period for the National Healthcare Safety Network (NHSN) Healthcare Personnel (HCP) Influenza Vaccination Reporting Measure included in the End-Stage Renal Disease (ESRD) Quality Incentive Program (QIP) for Payment Year 2020.

Nuclear magnetic resonance applied to the study of polymeric nano composites

International Nuclear Information System (INIS)

Tavares, Maria Ines Bruno

2011-01-01

Polymers and nanoparticles based nano composites were prepared by intercalation by solution. The obtained nano composites were characterized mainly by the nuclear magnetic spectroscopy (NMR), applying the analysis of carbon-13 (polymeric matrix), silicon-29 (nanoparticle), and by determination of spin-lattice relaxation of the hydrogen nucleus (T 1 H) (polymeric matrix). The NMR have presented a promising technique in the characterization of the nano charge dispersion in the studied polymeric matrixes.

The tensile strength of mechanical joint prototype of lontar fiber composite

Science.gov (United States)

Bale, Jefri; Adoe, Dominggus G. H.; Boimau, Kristomus; Sakera, Thomas

2018-03-01

In the present study, an experimental activity has been programmed to investigate the effect of joint prototype configuration on tensile strength of lontar (Borassus Flabellifer) fiber composite. To do so, a series of tests were conducted to establish the tensile strength of different joint prototype configuration specimen of lontar fiber composite. In addition, post observation of macroscope was used to map damage behavior. The analysis of lontar fiber composite is a challenge since the material has limited information than others natural fiber composites materials. The results shown that, under static tensile loading, the tensile strength of 13 MPa produced by single lap joint of lontar fiber composite is highest compare to 11 MPa of tensile strength generated by step lap joint and double lap joint where produced the lowest tensile strength of 6 MPa. It is concluded that the differences of tensile strength depend on the geometric dimensions of the cross-sectional area and stress distribution of each joint prototype configuration.

A Study of Hybrid Composite Hydroxyapatite (HA-Geopolymers as a Material for Biomedical Application

Directory of Open Access Journals (Sweden)

Saleha

2017-01-01

Full Text Available The main purpose of this research is to study the physical properties and microstructure characters of hybrid composites HA-geopolymers as a material for biomedical application. Hybrid composite HA–geopolymers were produced through alkaline activation method of metakaolin as a matrix and HA as the filler. HA was synthesized from eggshell particles by using a precipitation method. The addition of HA in metakaolin paste was varied from 0.5%, 1.0%, 1.5%, and 2.0% relative the weight of metakaolin. FTIR was used to examine the absorption bands the composites. X-ray diffraction (XRD was used to study the crystal structure of the starting and the resulting materials. Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS was used to investigate the surface morphology of the composites. The thermal properties of the samples was examined by means of Differential Scanning Calorimetry (DSC. Capacitance measurement was conducted to investigate the bioactive properties of HA. The study results suggest that hybrid composite HA-geopolymers has a potential to be applied as a biomedical such as biosensor material.

CDIO Projects in Civil Engineering Study Program at DTU

DEFF Research Database (Denmark)

Krogsbøll, Anette; Simonsen, Claus; Christensen, Jørgen Erik

2011-01-01

or a design build project on each of the first four semesters. In this paper the four projects in the civil engineering study program are described along with a brief description of the entire study program. The aim is to provide additional information and documentation to accompany an exposition where......In 2008 all Bachelor of engineering study programs at the Technical University of Denmark (DTU) have been adopted to the “Conceive – Design – Implement – Operate” approach. As part of the necessary changes it was decided that all seven study programs should have a cross disciplinary project...... students present their projects. Learning outcomes, training and assessment of personal, professional and social engineering skills are described from a project point of view. Progression of engineering skills is discussed from a study program perspective. The interrelation between the various elements...

A study on wear behaviour of Al/6101/graphite composites

Directory of Open Access Journals (Sweden)

Pardeep Sharma

2017-03-01

Full Text Available The current research work scrutinizes aluminium alloy 6101-graphite composites for their mechanical and tribological behaviour in dry sliding environments. The orthodox liquid casting technique had been used for the manufacturing of composite materials and imperilled to T6 heat treatment. The content of reinforcement particles was taken as 0, 4, 8, 12 and 16 wt.% of graphite to ascertain it is prospective as self-lubricating reinforcement in sliding wear environments. Hardness, tensile strength and flexural strength of cast Al6101 metal matrix and manufactured composites were evaluated. Hardness, tensile strength and flexural strength decreases with increasing volume fraction of graphite reinforcement as compared to cast Al6101 metal matrix. Wear tests were performed on pin on disc apparatus to assess the tribological behaviour of composites and to determine the optimum volume fraction of graphite for its minimum wear rate. Wear rate reduces with increase in graphite volume fraction and minimum wear rate was attained at 4 wt.% graphite. The wear was found to decrease with increase in sliding distance. The average co-efficient of friction also reduces with graphite addition and its minimum value was found to be at 4 wt.% graphite. The worn surfaces of wear specimens were studied through scanning electron microscopy. The occurrence of 4 wt.% of graphite reinforcement in the composites can reveal loftier wear possessions as compared to cast Al6101 metal matrix.

Eating frequency and weight and body composition: a systematic review of observational studies.

Science.gov (United States)

Canuto, Raquel; da Silva Garcez, Anderson; Kac, Gilberto; de Lira, Pedro Israel Cabral; Olinto, Maria Teresa Anselmo

2017-08-01

The present review aimed to examine the association of eating frequency with body weight or body composition in adults of both sexes. PubMed, EMBASE and Scopus databases were searched. PRISMA and MOOSE protocols were followed. Observational studies published up to August 2016 were included. The methodological quality of the studies was assessed with the Downs and Black checklist. A systematic review of the literature. Adults (n 136 052); the majority of studies were developed in the USA and Europe. Thirty-one articles were included in the review: two prospective and twenty-nine cross-sectional studies. Thirteen per cent of the studies received quality scores above 80 %. The assessment of eating frequency and body composition or body weight varied widely across the studies. Potential confounders were included in 73 % of the studies. Fourteen studies reported an inverse association between eating frequency and body weight or body composition, and seven studies found a positive association. The majority of studies applied multiple analyses adjusted for potential confounders, such as sex, age, education, income, smoking, physical activity and alcohol intake. Six studies took into account under-reporting of eating frequency and/or energy intake in the analysis, and one investigated the mediation effect of energy intake. There is not sufficient evidence confirming the association between eating frequency and body weight or body composition when misreporting bias is taken into account. However, in men, a potential protective effect of high eating frequency was observed on BMI and visceral obesity.

Durability of aircraft composite materials

Science.gov (United States)

Dextern, H. B.

1982-01-01

Confidence in the long term durability of advanced composites is developed through a series of flight service programs. Service experience is obtained by installing secondary and primary composite components on commercial and military transport aircraft and helicopters. Included are spoilers, rudders, elevators, ailerons, fairings and wing boxes on transport aircraft and doors, fairings, tail rotors, vertical fins, and horizontal stabilizers on helicopters. Materials included in the evaluation are boron/epoxy, Kevlar/epoxy, graphite/epoxy and boron/aluminum. Inspection, maintenance, and repair results for the components in service are reported. The effects of long term exposure to laboratory, flight, and outdoor environmental conditions are reported for various composite materials. Included are effects of moisture absorption, ultraviolet radiation, and aircraft fuels and fluids.

Middle East Studies Teacher Training Program. Final Report.

Science.gov (United States)

Sefein, Naim A.

This guide presents a teacher training program in Middle Eastern studies and procedures for program implementation. Details concerning program announcement, participant selection, and travel accommodations are included. Participants attended an orientation and registration workshop and an intensive academic workshop before flying to Egypt for the…

Development of bonded composite doublers for the repair of oil recovery equipment.

Energy Technology Data Exchange (ETDEWEB)

Roach, David W.; Rackow, Kirk A.

2005-06-01

An unavoidable by-product of a metallic structure's use is the appearance of crack and corrosion flaws. Economic barriers to the replacement of these structures have created an aging infrastructure and placed even greater demands on efficient and safe repair methods. In the past decade, an advanced composite repair technology has made great strides in commercial aviation use. Extensive testing and analysis, through joint programs between the Sandia Labs FAA Airworthiness Assurance Center and the aviation industry, have proven that composite materials can be used to repair damaged aluminum structure. Successful pilot programs have produced flight performance history to establish the durability of bonded composite patches as a permanent repair on commercial aircraft structures. With this foundation in place, this effort is adapting bonded composite repair technology to civil structures. The use of bonded composite doublers has the potential to correct the difficulties associated with current repair techniques and the ability to be applied where there are no rehabilitation options. It promises to be cost-effective with minimal disruption to the users of the structure. This report concludes a study into the application of composite patches on thick steel structures typically used in mining operations. Extreme fatigue, temperature, erosive, and corrosive environments induce an array of equipment damage. The current weld repair techniques for these structures provide a fatigue life that is inferior to that of the original plate. Subsequent cracking must be revisited on a regular basis. The use of composite doublers, which do not have brittle fracture problems such as those inherent in welds, can help extend the structure's fatigue life and reduce the equipment downtime. Two of the main issues for adapting aircraft composite repairs to civil applications are developing an installation technique for carbon steel and accommodating large repairs on extremely thick

Morphology and thermal degradation study of poly(lactic acid)/synthetic mica composites

International Nuclear Information System (INIS)

Souza, D.H.S.; Dias, M.L.

2010-01-01

Poly(lactic acid) (PLA)/synthetic mica composites has been little studied in the literature. In this work, an organophilic synthetic mica was used to prepare PLA nanocomposites. The composites were obtained at an internal mixer containing 3, 5, 7 and 10 wt% of mica. The materials were analyzed by x-ray diffraction, thermogravimetric analysis and gel permeation chromatography. (author)

7 CFR 3400.11 - Composition of peer review groups.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Composition of peer review groups. 3400.11 Section..., EDUCATION, AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE SPECIAL RESEARCH GRANTS PROGRAM Scientific Peer Review of Research Grant Applications § 3400.11 Composition of peer review groups. (a) Peer review group...

Material Programming

DEFF Research Database (Denmark)

Vallgårda, Anna; Boer, Laurens; Tsaknaki, Vasiliki

2017-01-01

. Consequently we ask what the practice of programming and giving form to such materials would be like? How would we be able to familiarize ourselves with the dynamics of these materials and their different combinations of cause and effect? Which tools would we need and what would they look like? Will we program......, and color, but additionally being capable of sensing, actuating, and computing. Indeed, computers will not be things in and by themselves, but embedded into the materials that make up our surroundings. This also means that the way we interact with computers and the way we program them, will change...... these computational composites through external computers and then transfer the code them, or will the programming happen closer to the materials? In this feature we outline a new research program that floats between imagined futures and the development of a material programming practice....

Vertical circulation and thermospheric composition: a modelling study

Directory of Open Access Journals (Sweden)

H. Rishbeth

Full Text Available The coupled thermosphere-ionosphere-plasmasphere model CTIP is used to study the global three-dimensional circulation and its effect on neutral composition in the midlatitude F-layer. At equinox, the vertical air motion is basically up by day, down by night, and the atomic oxygen/molecular nitrogen [O/N₂] concentration ratio is symmetrical about the equator. At solstice there is a summer-to-winter flow of air, with downwelling at subauroral latitudes in winter that produces regions of large [O/N₂] ratio. Because the thermospheric circulation is influenced by the high-latitude energy inputs, which are related to the geometry of the Earth's magnetic field, the latitude of the downwelling regions varies with longitude. The downwelling regions give rise to large F2-layer electron densities when they are sunlit, but not when they are in darkness, with implications for the distribution of seasonal and semiannual variations of the F2-layer. It is also found that the vertical distributions of O and N₂ may depart appreciably from diffusive equilibrium at heights up to about 160 km, especially in the summer hemisphere where there is strong upwelling.

Atmospheric composition and structure (thermosphere · composition and chemistry · Ionosphere (ionosphere · atmosphere interactions

Undergraduate International Studies and Foreign Language Program

Science.gov (United States)

Office of Postsecondary Education, US Department of Education, 2012

2012-01-01

The Undergraduate International Studies and Foreign Language Program provides funds to institutions of higher education, a consortia of such institutions, or partnerships between nonprofit organizations and institutions of higher education to plan, develop, and implement programs that strengthen and improve undergraduate instruction in…

Studies of heavy metal contents and microbial composition of ...

African Journals Online (AJOL)

This study investigated the heavy metal content and microbial composition of rhizosphere of Panicum maximum obtained from some auto mechanic workshops in Benin City, Nigeria. The grass was uprooted and soil sample was taken from its rhizosphere. The sample were labeled appropriately and immediately transported ...

The pedagogy of Short-Term Study-Abroad Programs

Directory of Open Access Journals (Sweden)

Jude Gonsalvez

2013-10-01

Full Text Available This paper focuses on establishing guidelines on the pedagogy of short term study abroad programs. This study follows 33 students who participated in a short-term study-abroad program to India with the researcher from 2006 through 2011. The study relies heavily on the student reflections and expressions as they experienced them. It is qualitative in nature. Focus groups were the main method of data collection, where participants were invited to reflect, express, and share their experiences with one another. This provided an opportunity for the participants to come together, relive their experiences, and help provide information as to how and what type of an influence this short-term study-abroad program provided.

A FRAMEWORK FOR PERFORMANCE EVALUATION AND MONITORING OF PUBLIC HEALTH PROGRAM USING COMPOSITE PERFORMANCE INDEX

Directory of Open Access Journals (Sweden)

Susanta Kumar Gauri

2017-12-01

Full Text Available A public health program (PHP taken up by the government of a country refers to all organized measures to prevent disease and promote health among the population, by providing different planned cares/services to the people. Usually, the target population for different PHP are different. The basic requirement for success of a PHP is to ensure that all the planned cares/services are reached to each member of the target population. Therefore, the important performance measures for a PHP are the implementation status of all the planned cares/services under the PHP. However, management and monitoring of a PHP become quite difficult by interpreting separately the information contained in a large number of performance measures. Therefore, usually a metric, called composite performance index (CPI, is evaluated to understand the overall performance of a PHP. However, due a scaling operation involved in the CPI computation procedure, the CPI value does not reveal the true overall implementation status of a PHP and consequently, it is effective for management of a PHP. This paper presents a new approach for CPI computation, in which scaling/normalization of the performance variables is not required and therefore, it can be used for monitoring the true overall implementation status of a PHP in a region. A systematic approach for monitoring a PHP using the CPI values is proposed and applied for monitoring the maternal and child healthcare (MCH program. The results are found effective towards continuous improvement of implementation status.

Best Practices in Academic Management. Study Programs Classification Model

Directory of Open Access Journals (Sweden)

Ofelia Ema Aleca

2016-05-01

Full Text Available This article proposes and tests a set of performance indicators for the assessment of Bachelor and Master studies, from two perspectives: the study programs and the disciplines. The academic performance at the level of a study program shall be calculated based on success and efficiency rates, and at discipline level, on the basis of rates of efficiency, success and absenteeism. This research proposes a model of classification of the study programs within a Bachelor and Master cycle based on the education performance and efficiency. What recommends this model as a best practice model in academic management is the possibility of grouping a study program or a discipline in a particular category of efficiency

Making of composite type energy introduction models in cities; Toshi ni okeru fukugogata energy donyu model no sakusei

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The paper made and studied simulation models in case of introducing new energy of composite type to cities. In the study, using a standard composition unit of city as a cluster, the compositional element was divided into 25 cells, which were divided into the residence superiority cell and the business superiority cell. The residence superiority cell was divided into highrise and lowrise. The calculation program is to simulate effects of introducing new energy such as the photovoltaic power generation, solar energy utilization, waste power generation, cogeneration, and unused energy like river water and waste water. Using the program, the analysis of sensitivity was conducted concerning how the outputs will change according to differences in energy consuming composition in the urban area. The calculation was conducted concerning local cities of the warm area, local cities of the cold area, local cities of the subtropical area, residence/working-place neighboring core cities in the warm area, central areas of large cities of the warm area, and new towns of the warm area. 28 figs., 27 tabs.

Study of samarium modified lead zirconate titanate and nickel zinc ferrite composite system

Energy Technology Data Exchange (ETDEWEB)

Rani, Rekha [Department of Physics, SD PG College, Panipat 132103 (India); School of Physics and Materials Science, Thapar University, Patiala 147004 (India); Juneja, J.K., E-mail: jk_juneja@yahoo.com [Department of Physics, Hindu College, Sonepat 131001 (India); Singh, Sangeeta [Department of Physics, GVM Girls College, Sonepat 131001 (India); Raina, K.K. [School of Physics and Materials Science, Thapar University, Patiala 147004 (India); Prakash, Chandra [Solid State Physics Laboratory, Timarpur, Delhi 110054 (India)

2015-03-15

In the present work, composites of samarium substituted lead zirconate titanate and nickel zinc ferrite with compositional formula 0.95Pb{sub 1−3x/2} Sm{sub x}Zr{sub 0.65}Ti{sub 0.35}O{sub 3}–0.05Ni{sub 0.8}Zn{sub 0.2}Fe{sub 2}O{sub 4} (x=0, 0.01, 0.02 and 0.03) were prepared by the conventional solid state route. X-ray diffraction analysis was carried out to confirm the coexistence of individual phases. Microstructural study was done by using scanning electron microscope. Dielectric constant and loss were studied as a function of temperature and frequency. To study ferroelectric and magnetic properties of the composite samples, corresponding P–E and M–H hysteresis loops were recorded. Change in magnetic properties of electrically poled composite sample (x=0.02) was studied to confirm the magnetoelectric (ME) coupling. ME coefficient (dE/dH) of the samples (x=0 and 0.02) was measured as a function of DC magnetic field. - Highlights: • We are reporting the effect of Sm substitution on PZT–NiZn ferrite composites. • Observation of both P–E and M–H loops confirms ferroelectric and magnetic ordering. • With Sm substitution, significant improvement in properties was observed. • Increase in magnetization for electrically poled sample is evidence of ME coupling. • Electric polarization is generated by applying magnetic field.

Predictions of the product compositions for combustion or gasification of biomass and others hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Rocha, Hendrick Maxil Zarate; Itai, Yuu; Nogueira, Manoel Fernandes Martins; Moraes, Sinfronio Brito; Rocha, Brigida Ramati Pereira da [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Faculdade de Engenharia Mecanica]. E-mails: hendrick@ufpa.br; yuuitai@ufpa.br; mfmn@ufpa.br; sbrito@ufpa.br; brigida@ufpa.br

2008-07-01

Processes involving combustion and gasification are object of study of many researchers. To simulate these processes in a detailed way, it is necessary to solve equations for chemical kinetics whose resolution many times is difficult due lack of information in the literature a simples way to bypass tis problem is due the chemical equilibrium. Prediction of the flu gases composition through chemical equilibrium is an important step in the mathematical modelling for gasification and combustion processes. Some free programs exists to solve problems that involve the chemical equilibrium, such as STANJAN, CEA, GASEQ, CANTERA and others.These programs have difficulty for cases involving fuel such as: biomass, vegetable oils, biodiesel, natural gas, etc., because they do not have database with the fuel composition and is hard to supply their HHV and their elementary analysis. In this work, using numeric methods, a program was developed to predict the gases composition on equilibrium after combustion and gasification processes with the for constant pressure or volume. In the program the chemical formula of the fuel is defined as C{sub x}H{sub y}O{sub z}N{sub w}S{sub v}A{sub u} that reacts with an gaseous oxidizer composed by O{sub 2}, N{sub 2}, Ar, He, CO{sub 2} e H{sub 2}O to have as final result the composition of the products CO{sub 2}, CO, H{sub 2}O, H{sub 2}, H, OH, O{sub 2}, O, N{sub 2}, NO, SO{sub 2}, CH{sub 4}, Ar, He, and ash. To verify the accuracy of the calculated values, it was compared with the program CEA (developed by NASA) and with experimental data obtained from literature. (author)

Studies on the mechanical properties of woven jute fabric reinforced poly(l-lactic acid composites

Directory of Open Access Journals (Sweden)

G.M. Arifuzzaman Khan

2016-01-01

Full Text Available Development of ecofriendly biocomposites to replace non-biodegradable synthetic fiber composites is the main objective of this study. To highlight the biocomposites as a perfect replacement, the plain woven jute fabric (WJF reinforced poly(l-lactic acid (PLLA composites were prepared by the hot press molding method. The influence of woven structure and direction on the mechanical properties i.e. tensile, flexural and impact properties was investigated. The average tensile strength (TS, tensile modulus (TM, flexural strength (FS, flexural modulus (FM, and impact strength (IS of untreated woven jute composite (in warp direction were improved about 103%, 211%, 95.2%, 42.4% and 85.9%, respectively and strain at maximum tensile stress for composite samples was enhanced by 11.7%. It was also found that the strengths and modulus of composites in warp direction are higher than those in weft direction. WJF composites in warp and weft directions presented superior mechanical properties than non-woven jute fabric (NWJF composites. Chemical treatment of jute fabric through benzoylation showed a positive effect on the properties of composites. Morphological studies by SEM demonstrated that better adhesion between the treated fabric and PLLA was achieved.

7 CFR 3415.11 - Composition of peer review groups.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Composition of peer review groups. 3415.11 Section... PROGRAM Scientific Peer Review of Research Grant Applications § 3415.11 Composition of peer review groups. (a) Peer review group members and ad hoc reviewers will be selected based upon their training and...

7 CFR 3411.11 - Composition of peer review groups.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Composition of peer review groups. 3411.11 Section... PROGRAM Scientific Peer Review of Research Grant Applications § 3411.11 Composition of peer review groups. (a) Peer review group members and ad hoc reviewers will be selected based upon their training and...

USDA's National Food and Nutrient Analysis Program (NFNAP) produces high-quality data for USDA food composition databases: Two decades of collaboration.

Science.gov (United States)

Haytowitz, David B; Pehrsson, Pamela R

2018-01-01

For nearly 20years, the National Food and Nutrient Analysis Program (NFNAP) has expanded and improved the quantity and quality of data in US Department of Agriculture's (USDA) food composition databases (FCDB) through the collection and analysis of nationally representative food samples. NFNAP employs statistically valid sampling plans, the Key Foods approach to identify and prioritize foods and nutrients, comprehensive quality control protocols, and analytical oversight to generate new and updated analytical data for food components. NFNAP has allowed the Nutrient Data Laboratory to keep up with the dynamic US food supply and emerging scientific research. Recently generated results for nationally representative food samples show marked changes compared to previous database values for selected nutrients. Monitoring changes in the composition of foods is critical in keeping FCDB up-to-date, so that they remain a vital tool in assessing the nutrient intake of national populations, as well as for providing dietary advice. Published by Elsevier Ltd.

A Semantics for Modular General Logic Programs

NARCIS (Netherlands)

Etalle, Sandro

1998-01-01

Modular programs are built as a combination of separate modules, which may be developed and verified separately. Therefore, in order to reason over such programs, compositionality plays a crucial role: the semantics of the whole program must be obtainable as a simple function from the semantics of

A semantics for modular general logic programs

NARCIS (Netherlands)

Etalle, S.

1998-01-01

Modular programs are built as a combination of separate modules, which may be developed and verified separately. Therefore, in order to reason over such programs, compositionality plays a crucial role: the semantics of the whole program must be obtainable as a simple function from the semantics of

Feature-Oriented Programming with Object Algebras

NARCIS (Netherlands)

B.C.d.S. Oliveira (Bruno); T. van der Storm (Tijs); A. Loh; W.R. Cook

2013-01-01

htmlabstractObject algebras are a new programming technique that enables a simple solution to basic extensibility and modularity issues in programming languages. While object algebras excel at defining modular features, the composition mechanisms for object algebras (and features) are still

A Study on Creep Behavior of Wood Flour- Recycled Polypropylene Composite

Directory of Open Access Journals (Sweden)

Saman Ghahri

2013-06-01

Full Text Available The creep behavior of wood flour- recycled polypropylene composites (with and without compatibilizer has been evaluated in this study. For this purpose, virgin polypropylene (PP was thermo-mechanically degraded by five times of extrusion under controlled conditions in a twin-screw extruder at a rotor speed of 100 rpm and at temperature of 1900C. The virgin and recycled polypropylene were mixed with the wood flour (50/50% W/W as well as the compatibilizer (0, 2% W/W by a counter-rotating twin-screw extruder to manufacture the wood flour-PP composites (WPCs samples. The nominal cross section of the manufactured composites was 70×10 mm2. Short term flexural creep test at 30% of ultimate bending load was performed by using flexural creep equipment. The total time to complete every test was 120 min (60 min creep and 60 min recovery. Results revealed that recycling of the PP reduced the creep resistance in composites containing recycled polypropylene. Also results have shown that with the presence of compatibilizer (MAPP creep deflection, creep factor and relative creep decrease and creep modulus increase. The composites containing virgin PP and MAPP exhibited higher creep resistance than those containing recycled PP.

Longitudinal study of body composition in spinal cord injury patients

Directory of Open Access Journals (Sweden)

Roop Singh

2014-01-01

Full Text Available Background: Bone mass loss and muscle atrophy are the frequent complications occurring after spinal cord injury (SCI. The potential risks involved with these changes in the body composition have implications for the health of the SCI individual. Thus, there is a need to quantitate and monitor body composition changes accurately in an individual with SCI. Very few longitudinal studies have been reported in the literature to assess body composition and most include relatively small number of patients. The present prospective study aimed to evaluate the body composition changes longitudinally by DEXA in patients with acute SCI. Materials and Methods: Ninety five patients with acute SCI with neurological deficits were evaluated for bone mineral content (BMC, body composition [lean body mass (LBM and fat mass] by dual-energy X-ray absorptiometry during the first year of SCI. Results: There was a significant decrease in BMC ( P < 0.05 and LBM ( P < 0.05 and increase in total body fat mass (TBFM and percentage fat at infra-lesional sites. The average decrease was 14.5% in BMC in lower extremities, 20.5% loss of LBM in legs and 15.1% loss of LBM in trunk, and increase of 0.2% in fat mass in legs and 17.3% increased fat in the lower limbs at 1 year. The tetraplegic patients had significant decrease in arm BMC ( P < 0.001, arm LBM ( P < 0.01 and fat percentage ( P < 0.01 compared to paraplegics. Patients with complete motor injury had higher values of TBFM and fat percentage, but comparable values of BMC and LBM to patients with incomplete motor injury. Conclusions: Our findings suggest that there is a marked decrease in BMC and LBM with increase in adiposity during the first year of SCI. Although these changes depend on the level and initial severity of lesions, they are also influenced by the neurological recovery after SCI.

Investigation of properties and performance of ceramic composite components: Final report on Phases 3 and 4

Energy Technology Data Exchange (ETDEWEB)

Curtin, W.A.; Halverson, H.; Carter, R.H.; Miraj, N.; Reifsnider, K.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1998-01-15

The objective of the Fossil Energy Advanced Research and Technology Development (AR and TD) Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The research program of the Materials Response Group at Virginia Tech addresses the need for reliable and durable structural ceramic composites to perform in high temperature environments. The research effort provides an experimental and analytical basis for the transition from properties of materials to performance of actual component structures. Phases 1 and 2 of the present program focused on the development of test capabilities, initial studies of component mechanical response under various conditions and the development of a life prediction methodology. These efforts have been described in previous reports. This report summarizes the major tasks completed under Phases 3 and 4 of the project. Overall, the authors have made significant progress in a broad spectrum of tasks in this program. Their efforts have encompassed component evaluation, assessment of new SiC-based composites with improved high-temperature potential, development of oxide coating materials for SiC, and the extension and development of new models for predicting the durability of composite components under specific operating conditions for various CMC applications. Each of these areas of work is an important area for achieving the ultimate goal of usable SiC-based composites in high-temperature corrosive environments typical of fossil energy applications.

Humidity Effects on Soluble Core Mechanical and Thermal Properties (Polyvinyl Alcohol/Microballoon Composite)

Science.gov (United States)

1993-01-01

This document constitutes the final report for the study of humidity effects and loading rate on soluble core (PVA/MB composite material) mechanical and thermal properties. This report describes test results, procedures employed, and any unusual occurrences or specific observations associated with this test program.

Advanced composite structural concepts and material technologies for primary aircraft structures

Science.gov (United States)

Jackson, Anthony

1991-01-01

Structural weight savings using advanced composites have been demonstrated for many years. Most military aircraft today use these materials extensively and Europe has taken the lead in their use in commercial aircraft primary structures. A major inhibiter to the use of advanced composites in the United States is cost. Material costs are high and will remain high relative to aluminum. The key therefore lies in the significant reduction in fabrication and assembly costs. The largest cost in most structures today is assembly. As part of the NASA Advanced Composite Technology Program, Lockheed Aeronautical Systems Company has a contract to explore and develop advanced structural and manufacturing concepts using advanced composites for transport aircraft. Wing and fuselage concepts and related trade studies are discussed. These concepts are intended to lower cost and weight through the use of innovative material forms, processes, structural configurations and minimization of parts. The approach to the trade studies and the downselect to the primary wing and fuselage concepts is detailed. The expectations for the development of these concepts is reviewed.

The Brazilian Cardioprotective Nutritional Program to reduce events and risk factors in secondary prevention for cardiovascular disease: study protocol (The BALANCE Program Trial).

Science.gov (United States)

Weber, Bernardete; Bersch-Ferreira, Ângela Cristine; Torreglosa, Camila Ragne; Ross-Fernandes, Maria Beatriz; da Silva, Jacqueline Tereza; Galante, Andrea Polo; Lara, Enilda de Sousa; Costa, Rosana Perim; Soares, Rafael Marques; Cavalcanti, Alexandre Biasi; Moriguchi, Emilio H; Bruscato, Neide M; Kesties; Vivian, Lilian; Schumacher, Marina; de Carli, Waldemar; Backes, Luciano M; Reolão, Bruna R; Rodrigues, Milena P; Baldissera, Dúnnia M B; Tres, Glaucia S; Lisbôa, Hugo R K; Bem, João B J; Reolão, Jose B C; Deucher, Keyla L A L; Cantarelli, Maiara; Lucion, Aline; Rampazzo, Daniela; Bertoni, Vanessa; Torres, Rosileide S; Verríssimo, Adriana O L; Guterres, Aldair S; Cardos, Andrea F R; Coutinho, Dalva B S; Negrão, Mayara G; Alencar, Mônica F A; Pinho, Priscila M; Barbosa, Socorro N A A; Carvalho, Ana P P F; Taboada, Maria I S; Pereira, Sheila A; Heyde, Raul V; Nagano, Francisca E Z; Baumgartner, Rebecca; Resende, Fernanda P; Tabalipa, Ranata; Zanini, Ana C; Machado, Michael J R; Araujo, Hevila; Teixeira, Maria L V; Souza, Gabriela C; Zuchinali, Priccila; Fracasso, Bianca M; Ulliam, Karen; Schumacher, Marina; Pierotto, Moara; Hilário, Thamires; Carlos, Daniele M O; Cordeiro, Cintia G N C; Carvalho, Daniele A; Gonçalves, Marília S; Vasconcelos, Valdiana B; Bosquetti, Rosa; Pagano, Raira; Romano, Marcelo L P; Jardim, César A; de Abreu, Bernardo N A; Marcadenti, Aline; Schmitt, Alessandra R; Tavares, Angela M V; Faria, Christiane C; Silva, Flávia M; Fink, Jaqueline S; El Kik, Raquel M; Prates, Clarice F; Vieira, Cristiane S; Adorne, Elaine F; Magedanz, Ellen H; Chieza, Fernanda L; Silva, Ingrid S; Teixeira, Joise M; Trescastro, Eduardo P; Pellegrini, Lívia A; Pinto, Jéssika C; Telles, Cristina T; Sousa, Antonio C S; Almeida, Andreza S; Costa, Ariane A; Carmo, José A C; Silva, Juliana T; Alves, Luciana V S; Sales, Saulo O C; Ramos, Maria E M; Lucas, Marilia C S; Damiani, Monica; Cardoso, Patricia C; Ramos, Salvador S; Dantas, Clenise F; Lopes, Amanda G; Cabral, Ana M P; Lucena, Ana C A; Medeiros, Auriene L; Terceiro, Bernardino B; Leda, Neuma M F S; Baía, Sandra R D; Pinheiro, Josilene M F; Cassiano, Alexandra N; Melo, Andressa N L; Cavalcanti, Anny K O; Souza, Camila V S; Queiroz, Dayanna J M; Farias, Hercilla N C F; Souza, Larissa C F; Santos, Letícia S; Lima, Luana R M; Hoffmann, Meg S; Ribeiro, Átala S Silva; Vasconcelos, Daniel F; Dutra, Eliane S; Ito, Marina K; Neto, José A F; Santos, Alexsandro F; Sousa, Rosângela M L; Dias, Luciana Pereira P; Lima, Maria T M A; Modanesi, Victor G; Teixeira, Adriana F; Estrada, Luciana C N C D; Modanesi, Paulo V G; Gomes, Adriana B L; Rocha, Bárbara R S; Teti, Cristina; David, Marta M; Palácio, Bruna M; Junior, Délcio G S; Faria, Érica H S; Oliveira, Michelle C F; Uehara, Rose M; Sasso, Sandramara; Moreira, Annie S B; Cadinha, Ana C A H; Pinto, Carla W M; Castilhos, Mariana P; Costa, Mariana; Kovacs, Cristiane; Magnoni, Daniel; Silva, Quênia; Germini, Michele F C A; da Silva, Renata A; Monteiro, Aline S; dos Santos, Karina G; Moreira, Priscila; Amparo, Fernanda C; Paiva, Catharina C J; Poloni, Soraia; Russo, Diana S; Silveira, Izabele V; Moraes, Maria A; Boklis, Mirena; Cardoso, Quinto I; Moreira, Annie S B; Damaceno, Aline M S; Santos, Elisa M; Dias, Glauber M; Pinho, Cláudia P S; Cavalcanti, Adrilene C; Bezerra, Amanda S; Queiroga, Andrey V; Rodrigues, Isa G; Leal, Tallita V; Sahade, Viviane; Amaral, Daniele A; Souza, Diana S; Araújo, Givaldo A; Curvello, Karine; Heine, Manuella; Barretto, Marília M S; Reis, Nailson A; Vasconcelos, Sandra M L; Vieira, Danielly C; Costa, Francisco A; Fontes, Jessica M S; Neto, Juvenal G C; Navarro, Laís N P; Ferreira, Raphaela C; Marinho, Patrícia M; Abib, Renata Torres; Longo, Aline; Bertoldi, Eduardo G; Ferreira, Lauren S; Borges, Lúcia R; Azevedo, Norlai A; Martins, Celma M; Kato, Juliana T; Izar, Maria C O; Asoo, Marina T; de Capitani, Mariana D; Machado, Valéria A; Fonzar, Waléria T; Pinto, Sônia L; Silva, Kellen C; Gratão, Lúcia H A; Machado, Sheila D; de Oliveira, Susane R U; Bressan, Josefina; Caldas, Ana P S; Lima, Hatanne C F M; Hermsdorff, Helen H M; Saldanha, Tânia M; Priore, Sílvia E; Feres, Naoel H; Neves, Adila de Queiroz; Cheim, Loanda M G; Silva, Nilma F; Reis, Silvia R L; Penafort, Andreza M; de Queirós, Ana Paula O; Farias, Geysa M N; de los Santos, Mônica L P; Ambrozio, Cíntia L; Camejo, Cirília N; dos Santos, Cristiano P; Schirmann, Gabriela S; Boemo, Jorge L; Oliveira, Rosane E C; Lima, Súsi M B; Bortolini, Vera M S; Matos, Cristina H; Barretta, Claiza; Specht, Clarice M; de Souza, Simone R; Arruda, Cristina S; Rodrigues, Priscila A; Berwanger, Otávio

2016-01-01

This article reports the rationale for the Brazilian Cardioprotective Nutritional Program (BALANCE Program) Trial. This pragmatic, multicenter, nationwide, randomized, concealed, controlled trial was designed to investigate the effects of the BALANCE Program in reducing cardiovascular events. The BALANCE Program consists of a prescribed diet guided by nutritional content recommendations from Brazilian national guidelines using a unique nutritional education strategy, which includes suggestions of affordable foods. In addition, the Program focuses on intensive follow-up through one-on-one visits, group sessions, and phone calls. In this trial, participants 45 years or older with any evidence of established cardiovascular disease will be randomized to the BALANCE or control groups. Those in the BALANCE group will receive the afore mentioned program interventions, while controls will be given generic advice on how to follow a low-fat, low-energy, low-sodium, and low-cholesterol diet, with a view to achieving Brazilian nutritional guideline recommendations. The primary outcome is a composite of death (any cause), cardiac arrest, acute myocardial infarction, stroke, myocardial revascularization, amputation for peripheral arterial disease, or hospitalization for unstable angina. A total of 2468 patients will be enrolled in 34 sites and followed up for up to 48 months. If the BALANCE Program is found to decrease cardiovascular events and reduce risk factors, this may represent an advance in the care of patients with cardiovascular disease. Copyright © 2015 Elsevier Inc. All rights reserved.

The Study of the Composite Material Go/CF/PTFE Tribological Property

Directory of Open Access Journals (Sweden)

Wang Li-hu

2017-01-01

Full Text Available In this paper, the composite material Go/CF/PTFE tribological property was studied. The test of its mechanical property, and the fabrication of the filled PTEE composite material sample which is based on the technology of cold press molding and sinter molding proved that adding Go and CF moderately to the composite material was an efficient way to improve its mechanical property. Meanwhile the process of friction and wear trial and SEM analysis results of the micro-structure of wear pattern proved that the addition of the Go and CF tremendously improved the anti-wear property and that after the addition the plowing effect which took place on the material surface would turn into a kind of mixed wear effect that includes plowing effect and fatigue wear. Working as pinning and bridging, the Go which distributing uniformly in the matrix was able to improve the resistance and substantially resisted the crack propagation, therefore to a certain degree enhanced the intensity of composite material and prolong its lifespan.

Comparative study for the design of optimal composite pressure vessels

International Nuclear Information System (INIS)

Butt, A.M.; Haq, S.W.U.

2009-01-01

Composite pressure vessels require special design attention to the dome region because of the varying wind angles generated using the filament winding process. Geometric variations in the dome region cause the fiber to change angels and thickness and hence offer difficulty to acquire a constant stress profile (isotensoid). Therefore a dome contour which allows an isotensoid behavior is the required structure. Two design methods to generate dome profiles for similar dome openings were investigated namely Netting Analysis and Optimal Design method. Both methods assume that loads are carried by the fiber alone (monotropic) ignoring the complete composite behavior. Former method produced a lower dome internal volume and a higher fiber thickness as compared to the later optimal design method when studied against different normalized dome opening radiuses. The optimal dome contour was studied in ANSYS with a trial design. The dome was considered to have transversely isotropic property with a dome contour based on monotropic model. While investigating the dome with non linear large displacement finite element analysis, the dome still exhibited isotensoid behavior with transverse isotropic material assignment. Elliptic integrals were used to generate the optimal dome contours and hence elliptic dome contours were formed which were isotensoid in nature with complete composite representation. (author)

Impact of Aspect-Oriented Programming on the Quality of Novices’ Programs: A Comparative Study

Directory of Open Access Journals (Sweden)

Marija Katic

2013-06-01

Full Text Available Aspect-oriented programming has been introduced in order to increase the modularity of object-oriented programs and is claimed to improve software quality. Although there are various researches on this claim, the question to what extent aspect-oriented programming improves the quality of programs depending on a developer’s experience still remains. The purpose of this study is to investigate whether aspect-oriented programming used by novice programmers improves the quality of programs, in terms of software flexibility and readability (consequently reusability and maintainability as well. As a part of an undergraduate course in programming paradigms and languages, a systematic comparison between students’ object-oriented and aspect-oriented solutions of the same problem was driven. In order to drive this comparison we have established the basis for the development of the new quality assessment model consisting of software metrics for an objective evaluation and student survey for subjective evaluation. The results show that the use of aspect-oriented programming lead to novices’ programs that are easier to change and read (flexible and readable compared to object-oriented programs. What is more, administered survey showed that students perceive their programs as more flexible and readable.

Improving Turbine Performance with Ceramic Matrix Composites

Science.gov (United States)

DiCarlo, James A.

2007-01-01

Under the new NASA Fundamental Aeronautics Program, efforts are on-going within the Supersonics Project aimed at the implementation of advanced SiC/SiC ceramic composites into hot section components of future gas turbine engines. Due to recent NASA advancements in SiC-based fibers and matrices, these composites are lighter and capable of much higher service temperatures than current metallic superalloys, which in turn will allow the engines to operate at higher efficiencies and reduced emissions. This presentation briefly reviews studies within Task 6.3.3 that are primarily aimed at developing physics-based concepts, tools, and process/property models for micro- and macro-structural design, fabrication, and lifing of SiC/SiC turbine components in general and airfoils in particular. Particular emphasis is currently being placed on understanding and modeling (1) creep effects on residual stress development within the component, (2) fiber architecture effects on key composite properties such as design strength, and (3) preform formation processes so that the optimum architectures can be implemented into complex-shaped components, such as turbine vanes and blades.

Exercise program improved subjective dry eye symptoms for office workers.

Science.gov (United States)

Sano, Kokoro; Kawashima, Motoko; Takechi, Sayuri; Mimura, Masaru; Tsubota, Kazuo

2018-01-01

We investigated the benefits of a cognitive behavior therapy-based exercise program to reduce the dry eye symptoms of office workers. We recruited 11 office workers with dry eye symptoms, aged 31-64 years, who voluntarily participated in group health guidance at a manufacturing company. Participants learned about the role of physical activity and exercise in enhancing wellness and performed an exercise program at home 3 days per week for 10 weeks. We estimated the indexes of body composition, dry eye symptoms, and psychological distress using the Dry Eye-Related Quality of Life Score and the World Health Organization's Subjective Well-Being Inventory questionnaires pre- and postintervention. The 10-week exercise program and the questionnaires were completed by 48.1% (39 of 81) of the participants. Body composition did not change pre- and postintervention. However, the average of the Dry Eye-Related Quality of Life Score scores in participants with subjective dry eye significantly improved after the intervention. Moreover, the World Health Organization's Subjective Well-Being Inventory positive well-being score tended to increase after the intervention. In this study, we showed that a 10-week exercise program improved subjective dry eye symptoms of healthy office workers. Our study suggests that a cognitive behavior therapy-based exercise program can play an important role in the treatment of patients with dry eye disease.

“Climb!” – A Composition Case Study. Actualising and Replicating Virtual Spaces in Classical Music Composition and Performance

DEFF Research Database (Denmark)

Kallionpaa, Maria; Gasselseder, Hans-Peter

2018-01-01

, for example, the acoustics of the concert hall, the instrumentation, the qualities of the concert instrument, or the technologies used. Today´s electroacoustic repertoires frequently contain manipulation of (either physical or virtual) space or acoustic qualities, which sets new requirements...... to the capabilities of the performers. This leads to a question what these requirements may be and how can the performers and composers best deal with them? Can the space itself form part of the structure of a composition and/or performance? This chapter explores the topic through a composition case study “Climb...

Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women

Directory of Open Access Journals (Sweden)

Roberts Mike D

2010-11-01

Full Text Available Abstract Background This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss. Methods One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m-2, 44.8 ± 4.2% fat were randomized to either no diet + no exercise control group (CON a no diet + exercise control (ND, or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP] in addition to beginning a 3x•week-1 supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate. Results All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass and body composition via DXA (fat mass and % fat changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non

The Study on Thermal Expansion of Ceramic Composites with Addition of ZrW[2]O]8

OpenAIRE

Dedova, Elena Sergeevna; Shadrin, V. S.; Petrushina, M. Y.; Kulkov, Sergey Nikolaevich

2016-01-01

The studies on structure, phase composition and thermal properties of (Al[2]O[3] - 20 wt% ZrO[2]) - ZrW[2]O[8] ceramic composites obtained using nanosized, initial powders were conducted. Homogeneously distributed white particles on the polished surface of composites were observed. Phase composition of the composites was represented with corundum, monoclinic ZrO[2] and two modifications of ZrW[2]O[8] (tetragonal and cubic). Linear thermal expansion coefficient values of the composites were de...

Study of the temperature dependence of giant magnetoresistance in metallic granular composite

International Nuclear Information System (INIS)

Ju Sheng; Li, Z.-Y.

2002-01-01

The temperature dependence of the giant magnetoresistance of metallic granular composite is studied. It is considered that the composite contains both large magnetic grains with surface spin S' and small magnetic impurities. It is found that the decrease of surface spin S' of grain is the main cause of an almost linear decrease of giant magnetoresistance with the increase of temperature in high temperature range. The magnetic impurities, composed of several atoms, lead to an almost linear increase of the giant magnetoresistance with the decrease of temperature in low temperature range. Our calculations are in good agreement with recent experimental data for metallic nanogranular composites

Fetal Programming of Body Composition, Obesity, and Metabolic Function: The Role of Intrauterine Stress and Stress Biology

Directory of Open Access Journals (Sweden)

Sonja Entringer

2012-01-01

Full Text Available Epidemiological, clinical, physiological, cellular, and molecular evidence suggests that the origins of obesity and metabolic dysfunction can be traced back to intrauterine life and supports an important role for maternal nutrition prior to and during gestation in fetal programming. The elucidation of underlying mechanisms is an area of interest and intense investigation. In this perspectives paper we propose that in addition to maternal nutrition-related processes it may be important to concurrently consider the potential role of intrauterine stress and stress biology. We frame our arguments in the larger context of an evolutionary-developmental perspective that supports roles for both nutrition and stress as key environmental conditions driving natural selection and developmental plasticity. We suggest that intrauterine stress exposure may interact with the nutritional milieu, and that stress biology may represent an underlying mechanism mediating the effects of diverse intrauterine perturbations, including but not limited to maternal nutritional insults (undernutrition and overnutrition, on brain and peripheral targets of programming of body composition, energy balance homeostasis, and metabolic function. We discuss putative maternal-placental-fetal endocrine and immune/inflammatory candidate mechanisms that may underlie the long-term effects of intrauterine stress. We conclude with a commentary of the implications for future research and clinical practice.

Safety of GM crops: compositional analysis.

Science.gov (United States)

Brune, Philip D; Culler, Angela Hendrickson; Ridley, William P; Walker, Kate

2013-09-04

The compositional analysis of genetically modified (GM) crops has continued to be an important part of the overall evaluation in the safety assessment program for these materials. The variety and complexity of genetically engineered traits and modes of action that will be used in GM crops in the near future, as well as our expanded knowledge of compositional variability and factors that can affect composition, raise questions about compositional analysis and how it should be applied to evaluate the safety of traits. The International Life Sciences Institute (ILSI), a nonprofit foundation whose mission is to provide science that improves public health and well-being by fostering collaboration among experts from academia, government, and industry, convened a workshop in September 2012 to examine these and related questions, and a series of papers has been assembled to describe the outcomes of that meeting.

Optimization of medium composition for apple rootstocks

African Journals Online (AJOL)

User

2011-05-02

May 2, 2011 ... Key words: Apple rootstocks, medium composition, multiplication rate, plant growth regulators (PGRs). ... be extrapolated with the same success for another .... Analysis System (SAS) software program (SAS Institute Inc. 1999).

BlenX-based compositional modeling of complex reaction mechanisms

Directory of Open Access Journals (Sweden)

Judit Zámborszky

2010-02-01

Full Text Available Molecular interactions are wired in a fascinating way resulting in complex behavior of biological systems. Theoretical modeling provides a useful framework for understanding the dynamics and the function of such networks. The complexity of the biological networks calls for conceptual tools that manage the combinatorial explosion of the set of possible interactions. A suitable conceptual tool to attack complexity is compositionality, already successfully used in the process algebra field to model computer systems. We rely on the BlenX programming language, originated by the beta-binders process calculus, to specify and simulate high-level descriptions of biological circuits. The Gillespie's stochastic framework of BlenX requires the decomposition of phenomenological functions into basic elementary reactions. Systematic unpacking of complex reaction mechanisms into BlenX templates is shown in this study. The estimation/derivation of missing parameters and the challenges emerging from compositional model building in stochastic process algebras are discussed. A biological example on circadian clock is presented as a case study of BlenX compositionality.

ZK30-bioactive glass composites for orthopedic applications: A comparative study on fabrication method and characteristics

Energy Technology Data Exchange (ETDEWEB)

Huan, Z.G.; Leeflang, M.A. [Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Zhou, J., E-mail: j.zhou@tudelft.nl [Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Duszczyk, J. [Department of Biomechanical Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands)

2011-12-15

Highlights: Black-Right-Pointing-Pointer Biodegradable Mg-bioglass composites were made using casting; powder metallurgy. Black-Right-Pointing-Pointer Bioglass powder retained its composition and morphology. Black-Right-Pointing-Pointer Accelerated deposition of Ca; P ions on composites occurred due to bioglass. Black-Right-Pointing-Pointer Mg-bioglass composites made from powders had reduced degradation rates. Black-Right-Pointing-Pointer Powder metallurgy appeared to be better for making biodegradable composites. - Abstract: Previous in vivo studies on biodegradable magnesium alloys for orthopedic implant applications showed the need to improve early-stage bioactivity. Introducing bioactive particles into a magnesium alloy to form a metal matrix composite (MMC) represents an effective way to enhance the bioactivity of the alloy. In this study, composites with the ZK30 alloy as the matrix and the 45S5 bioactive glass (BG) as the reinforcement phase were fabricated using a semi-solid casting (SSC) method and a powder metallurgy (P/M) method. The SSC and P/M biocomposites with the same weight percents of bioactive glass particles were compared. Optical microscopy showed homogeneously dispered BG particles in the SSC and P/M composites. SEM and EDX analyses confirmed the retention of the morphological characteristics and composition of BG particles in the composites. However, the SSC composites exhibited micro-porous structures, while the P/M composites had nearly fully densified structures. As compared with the ZK30 matrix, the SSC composites exhibited significantly higher degradation rates, while the P/M composites possessed lower degradation rates. On the surface of all the composites, accelerated deposition of Ca and P ions occurred during immersion in the cell culture medium, indicating an improved surface bioactivity of the composites. The P/M method was found to be advantageous over the SSC method and could yield magnesium-matrix composites with enhanced

Advanced Industrial Materials Program. Annual progress report, FY 1993

Energy Technology Data Exchange (ETDEWEB)

Stooksbury, F. [comp.

1994-06-01

Mission of the AIM program is to commercialize new/improved materials and materials processing methods that will improve energy efficiency, productivity, and competitiveness. Program investigators in the DOE national laboratories are working with about 100 companies, including 15 partners in CRDAs. Work is being done on intermetallic alloys, ceramic composites, metal composites, polymers, engineered porous materials, and surface modification. The program supports other efforts in the Office of Industrial Technologies to assist the energy-consuming process industries. The aim of the AIM program is to bring materials from basic research to industrial application to strengthen the competitive position of US industry and save energy.

A study of composite models at LEP with ALEPH

International Nuclear Information System (INIS)

Badaud, F.

1992-04-01

Tests of composite models are performed in e + e - collisions in the vicinity of the Z 0 pole using the ALEPH detector. Two kinds of substructure effects are searched for: deviations of differential cross section for reactions e + e - → l + l - and e + e - → γ γ from standard model predictions, and direct search for excited neutrino. A new interaction, parametrized by a 4-fermion contact term, cell, is studied in lepton pair production reactions, assuming different chiralities of the currents. Lower limits on the compositeness scale Λ are obtained by fitting model predictions to the data. They are in the range from 1 to a few TeV depending on model and lepton flavour. Researches for the lightest excited particle that could be the excited neutrino, are presented

An eHealth program versus a standard care supervised health program and associated health outcomes in individuals with mobility disability: study protocol for a randomized controlled trial.

Science.gov (United States)

Berglind, Daniel; Nyberg, Gisela; Willmer, Mikaela; Persson, Margareta; Wells, Michael; Forsell, Yvonne

2018-04-27

Young adults with mobility disability (MD) are less likely to engage in regular physical activity (PA) compared with their able-bodied peers and inactive adults with a MD are more likely to report one or more chronic diseases compared to those who are physically active. Despite the vast amount of research published in the field of PA interventions over the past decades, little attention has been focused on interventions aiming to increase PA among individuals with MD. Thus, we propose to compare the effects of an eHealth program compared to a usual care supervised health program on levels of PA and other health behaviors. The current intervention will use a randomized controlled trial (RCT) design with two treatment groups (an eHealth program and a usual care supervised health program) in young adults with newly acquired MD. In total, 110 young adults (aged 18-40 years) with a MD, acquired within the past 3 years, will be recruited to participate in a 12-week intervention. The primary study outcome is accelerometer-measured time spent in moderate to vigorous PA. Secondary outcomes includes health-related quality of life, depression, stress, fitness, body composition, diet, musculoskeletal pain, motivation to exercise and work ability. There is a lack of RCTs investigating effective ways to increase levels of PA in young adults with MD. Increased levels of PA among this physically inactive population have the potential to substantially improve health-related outcomes, possibly more so than in the general population. The trial will put strong emphasis on optimizing exercise adherence and investigating feasibility in the two treatment programs. The Ethical Review Board (EPN) at Karolinska Institutet has approved the study (2017/1206-31/1). International Standard Randomised Controlled Trial Number (ISRCTN), reference number ISRCTN22387524 . Prospectively registered February 4, 2018.

Thermal Protective Coating for High Temperature Polymer Composites

Science.gov (United States)

Barron, Andrew R.

1999-01-01

The central theme of this research is the application of carboxylate-alumoxane nanoparticles as precursors to thermally protective coatings for high temperature polymer composites. In addition, we will investigate the application of carboxylate-alumoxane nanoparticle as a component to polymer composites. The objective of this research was the high temperature protection of polymer composites via novel chemistry. The significance of this research is the development of a low cost and highly flexible synthetic methodology, with a compatible processing technique, for the fabrication of high temperature polymer composites. We proposed to accomplish this broad goal through the use of a class of ceramic precursor material, alumoxanes. Alumoxanes are nano-particles with a boehmite-like structure and an organic periphery. The technical goals of this program are to prepare and evaluate water soluble carboxylate-alumoxane for the preparation of ceramic coatings on polymer substrates. Our proposed approach is attractive since proof of concept has been demonstrated under the NRA 96-LeRC-1 Technology for Advanced High Temperature Gas Turbine Engines, HITEMP Program. For example, carbon and Kevlar(tm) fibers and matting have been successfully coated with ceramic thermally protective layers.

The composite sequential clustering technique for analysis of multispectral scanner data

Science.gov (United States)

Su, M. Y.

1972-01-01

The clustering technique consists of two parts: (1) a sequential statistical clustering which is essentially a sequential variance analysis, and (2) a generalized K-means clustering. In this composite clustering technique, the output of (1) is a set of initial clusters which are input to (2) for further improvement by an iterative scheme. This unsupervised composite technique was employed for automatic classification of two sets of remote multispectral earth resource observations. The classification accuracy by the unsupervised technique is found to be comparable to that by traditional supervised maximum likelihood classification techniques. The mathematical algorithms for the composite sequential clustering program and a detailed computer program description with job setup are given.

Nutrient Requirements, Body Composition, and Health of Military Women

National Research Council Canada - National Science Library

Costello, Rebecca

1998-01-01

.... As pan of the Defense Women's Health Research Program, a new report from the Committee on Body Composition, Nutrition, and Health of Military Women of the Institute of the Institute of Medicine examines issues of body composition, fitness, and appearance standards and their impact on the health, nutritional status, and performance of active-duty women.

Aspect-Oriented Programming Using Composition Filters, in Object-Oriented Technology

NARCIS (Netherlands)

Aksit, Mehmet; Demeyer, S.; Bosch, H.G.P.; Tekinerdogan, B.

Software engineers may experience problems in modeling certain aspects while applying object-oriented techniques [4, 10, 11]. Composition-Filters are capable of expressing various different kinds of aspects in a uniform manner. These aspects are, for example, inheritance and delegation [1] and

The effects of an individualized exercise intervention on body composition in breast cancer patients undergoing treatment

OpenAIRE

Battaglini,Claudio; Bottaro,Martim; Dennehy,Carolyn; Rae,Logan; Shields,Edgar; Kirk,David; Hackney,Anthony

2007-01-01

CONTEXT AND OBJECTIVE: Changes in metabolism have been reported in the majority of patients undergoing cancer treatment, and these are usually characterized by progressive change in body composition. The effects of aerobic exercise programs to combat the cancer and cancer treatment-related side effects, which include the negative changes in body composition, have been extensively reported in the literature. However, few resistance exercise intervention studies have hypothesized that breast ca...

MRI: Modular reasoning about interference in incremental programming

OpenAIRE

Oliveira, Bruno C. D. S; Schrijvers, Tom; Cook, William R

2012-01-01

Incremental Programming (IP) is a programming style in which new program components are defined as increments of other components. Examples of IP mechanisms include: Object-oriented programming (OOP) inheritance, aspect-oriented programming (AOP) advice and feature-oriented programming (FOP). A characteristic of IP mechanisms is that, while individual components can be independently defined, the composition of components makes those components become tightly coupled, sh...

Development and validation of bonded composite doubler repairs for commercial aircraft.

Energy Technology Data Exchange (ETDEWEB)

Roach, Dennis Patrick; Rackow, Kirk A.

2007-07-01

repair using a substandard design and a flawed installation. In addition, the new Sol-Gel surface preparation technique was evaluated. Fatigue coupon tests produced Sol-Gel results that could be compared with a large performance database from conventional, riveted repairs. It was demonstrated that not only can composite doublers perform well in severe off-design conditions (low doubler stiffness and presence of defects in doubler installation) but that the Sol-Gel surface preparation technique is easier and quicker to carry out while still producing optimum bonding properties. Nondestructive inspection (NDI) methods were developed so that the potential for disbond and delamination growth could be monitored and crack growth mitigation could be quantified. The NDI methods were validated using full-scale test articles and the FedEx aircraft installations. It was demonstrated that specialized NDI techniques can detect flaws in composite doubler installations before they reach critical size. Probability of Detection studies were integrated into the FedEx training in order to quantify the ability of aircraft maintenance depots to properly monitor these repairs. In addition, Boeing Structural Repair and Nondestructive Testing Manuals were modified to include composite doubler repair and inspection procedures. This report presents the results from the FedEx Pilot Program that involved installation and surveillance of numerous repairs on operating aircraft. Results from critical NDI evaluations are reported in light of damage tolerance assessments for bonded composite doublers. This work has produced significant interest from airlines and aircraft manufacturers. The successful Pilot Program produced flight performance history to establish the durability of bonded composite patches as a permanent repair on commercial aircraft structures. This report discusses both the laboratory data and Pilot Program results from repair installations on operating aircraft to introduce composite

[A telemetrically-guided program for weight reduction in overweight subjects (the SMART study)].

Science.gov (United States)

Körtke, H; Frisch, S; Zittermann, A; Berthold, H K; El-Arousy, M; Götting, C; Kleesiek, K; Stehle, P; Körfer, R

2008-06-01

Compliance with weight reducing programs can be improved by intensive care and control. We tested a telemetrically-guided weight reduction program in overweight and obese persons. 200 outpatients (62 males) with a mean body mass index of 34 kg/m (2) and a mean age of 47 years participated in a prospective study for one year. During the first six months, telemetrical support (weight-transmission via Bluetooth (short range)-technology, 20-minutes telephone consultation with a nutritionist) was given weekly. After six months, participants were randomly assigned either to a group with further telemonitoring support (telemetric group) or to a group without contact to our clinic (control group). At baseline, and after six and twelve months, body weight, body composition (bioelectrical impedance analysis), and parameters of the metabolic syndrome were assessed at our clinic. 16 participants terminated the study prematurely during the first 6 months and 19 participants (10 from the telemetric group and 9 from the control group) during the second 6 months. According to the intention-to-treat principle, mean weight loss was 6.7 kg (p < 0,001), mean loss of body fat was 5.1 kg (p < 0,001), and mean loss of fat-free mass was 1.6 kg (p < 0,001) within the first six months. Moreover, metabolic and cardiovascular risk markers such as waist circumference, blood pressure, serum triglycerides and blood glucose declined significantly (p < 0,001). Prevalence of the metabolic syndrome fell from 49.5% to 42.0 % (p < 0,05). During the second six months body fat content, waist circumference, and blood glucose increased again in the control group but not in the telemetric group (p < 0,05-0,001). The telemetrically-guided weight loss program was a more efficacious measure than the less intensive support without telemonitoring.

A comparative evaluation of microleakage of restorations using silorane-based dental composite and methacrylate-based dental composites in Class II cavities: An in vitro study

Directory of Open Access Journals (Sweden)

Jambai Sampath Kumar Sivakumar

2016-01-01

Full Text Available Aim: The aim of this in vitro study was to evaluate and compare the microleakage of restorations using low shrinkage silorane-based dental composite and methacrylate-based dental composites in Class II cavity at the occlusal and gingival margins. Materials and Methods: Sixty mandibular molars were collected and divided into three experimental groups and one negative control group. Class II slot cavity was prepared on the mesial surface. Experimental groups were restored with Group I: silorane-based microhybrid composite, Group II: methacrylate-based nanohybrid composite, and Group III: Methacrylate-based microhybrid composite, respectively. Group IV: negative control. The samples were thermocycled, root apices were sealed with sticky wax and coated with nail varnish except 1 mm around the restoration. This was followed by immersion in 2% Rhodamine-B dye solution under vacuum at room temperature for 24 h. Then, the samples were sectioned longitudinally in the mesiodistal direction and evaluated under stereomicroscope ×40 magnification. Scoring was done according to the depth of dye penetration in to the cavity. Statistical analysis of the data was done. Results: The results were that no statistically significant difference in the microleakage at the occlusal margin for all the restorative materials, whereas at the gingival margin, silorane-based microhybrid composite showed less microleakage than the methacrylate-based nano- and micro-hybrid composites. Conclusion: In general, silorane-based microhybrid composite had less microleakage among the other materials used in this in vitro study.

Nondestructive evaluation of ceramic and metal matrix composites for NASA's HITEMP and enabling propulsion materials programs

Science.gov (United States)

Generazio, Edward R.

1992-01-01

In a preliminary study, ultrasonic, x-ray opaque, and fluorescent dye penetrants techniques were used to evaluate and characterize ceramic and metal matrix composites. Techniques are highlighted for identifying porosity, fiber alignment, fiber uniformity, matrix cracks, fiber fractures, unbonds or disbonds between laminae, and fiber-to-matrix bond variations. The nondestructive evaluations (NDE) were performed during processing and after thermomechanical testing. Specific examples are given for Si3N4/SiC (SCS-6 fiber), FeCrAlY/Al2O3 fibers, Ti-15-3/SiC (SCS-6 fiber) materials, and Si3N4/SiC (SCS-6 fiber) actively cooled panel components. Results of this study indicate that the choice of the NDE tools to be used can be optimized to yield a faithful and accurate evaluation of advanced composites.

SOILSOLN: A Program for Teaching Equilibria Modeling of Soil Solution Composition.

Science.gov (United States)

Wolt, Jeffrey D.

1989-01-01

Presents a computer program for use in teaching ion speciation in soil solutions. Provides information on the structure of the program, execution, and software specifications. The program estimates concentrations of ion pairs, hydrolytic species, metal-organic complexes, and free ions in solutions. (Author/RT)

Composite slab behavior and strength analysis under static and dynamic loads

Directory of Open Access Journals (Sweden)

Florin Radu HARIGA

2012-07-01

Full Text Available Steel-framed buildings are typically constructed using steel-deck-reinforced concrete floor slabs. The in-plane (or diaphragm strength and stiffness of the floor system are frequently utilized in the lateral load-resisting system design. This paper presents the results of an experimental research program in which four full size composite diaphragms were vertically loaded to the limit state, under static or dynamic loads. Two test specimens were provided with longitudinal steel-deck ribs, and the other two specimens with cross steel-deck ribs. Typical composite diaphragm limit states are described, and the controlling limit state for each of the full size tests is indicated. The interaction effects between the reinforced concrete slab and the steel girder on the composite slab strength and stiffness were mainly studied.

Stress wave calculations in composite plates using the fast Fourier transform.

Science.gov (United States)

Moon, F. C.

1973-01-01

The protection of composite turbine fan blades against impact forces has prompted the study of dynamic stresses in composites due to transient loads. The mathematical model treats the laminated plate as an equivalent anisotropic material. The use of Mindlin's approximate theory of crystal plates results in five two-dimensional stress waves. Three of the waves are flexural and two involve in-plane extensional strains. The initial value problem due to a transient distributed transverse force on the plate is solved using Laplace and Fourier transforms. A fast computer program for inverting the two-dimensional Fourier transform is used. Stress contours for various stresses and times after application of load are obtained for a graphite fiber-epoxy matrix composite plate. Results indicate that the points of maximum stress travel along the fiber directions.

Composite flywheel development completion report, May 1--September 30, 1976

Energy Technology Data Exchange (ETDEWEB)

Huddleston, R. L.; Kelly, J. J.; Knight, C. E.

1977-05-01

The program to design, fabricate, and performance test a prototype, vehicular-sized, composite flywheel is described. The overall program scope encompasses development of both the flywheel and its containment; however, the FY 1976-1976T objective was directed toward development of the flywheel and testing it in existing facilities. The development effort was successful, leading to successful testing of a flywheel design which demonstrated an energy density performance of 10.1 Wh/lb during spin testing. The initial application selected for development of the composite flywheel was the heat engine/flywheel hybrid propulsion system for a vehicle. This application was selected by the ERDA Advanced Physical Methods Branch staff because of its high potential for conservation of petroleum fuel in both the near and far-term time frames. Other applications, such as utility load leveling, represent potential areas for significant energy savings but require more extensive development programs and funding resources. Successful development of a high-performance, composite, vehicular flywheel represents one step along the development path leading toward larger, higher-energy storage flywheel applications.

Program Plan: field radionuclide migration studies in Climax granite

International Nuclear Information System (INIS)

Isherwood, D.; Raber, E.; Coles, D.; Stone, R.

1980-01-01

This Program Plan describes the field radionuclide migration studies we plan to conduct in the Climax granite at the Nevada Test Site. Laboratory support studies are included to help us understand the geochemical and hydrologic processes involved in the field. The Program Plan begins with background information (Section 1) on how this program fits into the National Waste Terminal Storage Program Plan and discusses the needs for field studies of this type. The objectives stated in Section 2 are in direct response to these needs, particularly the need to determine whether laboratory studies accurately reflect actual field conditions and the need for field testing to provide a data base for verification of hydrologic and mass transport models. The technical scope (Section 3) provides a work breakdown structure that integrates the various activities and establishes a base for the technical approach described in Section 4. Our approach combines an interactive system of field and laboratory migration experiments with the use of hydrologic models for pre-test predictions and data interpretation. Section 5 on program interfaces identifies how information will be transferred to other related DOE projects. A schedule of activities and major milestones (Section 6) and the budget necessary to meet the project objectives (Section 7) are included in the Program Plan. Sections 8 and 9 contain brief descriptions of how the technical and program controls will be established and maintained and an outline of our quality assurance program. This program plan is an initial planning document and provides a general description of activities. An Engineering Test Plan containing detailed experimental test plans, an instrumentation plan and equipment design drawings will be published as a separate document

Hybrid-Wing-Body Vehicle Composite Fuselage Analysis and Case Study

Science.gov (United States)

Mukhopadhyay, Vivek

2014-01-01

Recent progress in the structural analysis of a Hybrid Wing-Body (HWB) fuselage concept is presented with the objective of structural weight reduction under a set of critical design loads. This pressurized efficient HWB fuselage design is presently being investigated by the NASA Environmentally Responsible Aviation (ERA) project in collaboration with the Boeing Company, Huntington Beach. The Pultruded Rod-Stiffened Efficient Unitized Structure (PRSEUS) composite concept, developed at the Boeing Company, is approximately modeled for an analytical study and finite element analysis. Stiffened plate linear theories are employed for a parametric case study. Maximum deflection and stress levels are obtained with appropriate assumptions for a set of feasible stiffened panel configurations. An analytical parametric case study is presented to examine the effects of discrete stiffener spacing and skin thickness on structural weight, deflection and stress. A finite-element model (FEM) of an integrated fuselage section with bulkhead is developed for an independent assessment. Stress analysis and scenario based case studies are conducted for design improvement. The FEM model specific weight of the improved fuselage concept is computed and compared to previous studies, in order to assess the relative weight/strength advantages of this advanced composite airframe technology

Study on Electrical Properties of PALF Reinforced Bisphenol-A Composite

Directory of Open Access Journals (Sweden)

Vinod B.

2018-01-01

Full Text Available These days, composite materials successfully substitute the traditional materials due to its various significant applications. This paper examines the influence of fiber orientation and fiber length on electrical properties of PALF reinforced Bisphenol-A composite and explores the potential of using PALF as reinforcing material for electrical applications such as terminals, connectors, motor body cover, industrial and household plugs and circuit boards. The resistance and inductance of resin material is increased by 24.19% and 24.13% respectively after reinforcement of PALF in different orientations and its value increased by 37.93% and 37.81% respectively after reinforcement of PALF in different lengths. Similarly, Capacitance and Dielectric constant of resin material decreased by 19.44% and 19.39% respectively after reinforcement of PALF in different orientations and its value decreased by 27.67% and 27.50% respectively after reinforcement of PALF in different lengths. It can be inferred from this study that the fiber orientations and fiber lengths greatly effects the electrical properties of PALF composite.

Development of Textile Reinforced Composites for Aircraft Structures

Science.gov (United States)

Dexter, H. Benson

1998-01-01

NASA has been a leader in development of composite materials for aircraft applications during the past 25 years. In the early 1980's NASA and others conducted research to improve damage tolerance of composite structures through the use of toughened resins but these resins were not cost-effective. The aircraft industry wanted affordable, robust structures that could withstand the rigors of flight service with minimal damage. The cost and damage tolerance barriers of conventional laminated composites led NASA to focus on new concepts in composites which would incorporate the automated manufacturing methods of the textiles industry and which would incorporate through-the-thickness reinforcements. The NASA Advanced Composites Technology (ACT) Program provided the resources to extensively investigate the application of textile processes to next generation aircraft wing and fuselage structures. This paper discusses advanced textile material forms that have been developed, innovative machine concepts and key technology advancements required for future application of textile reinforced composites in commercial transport aircraft. Multiaxial warp knitting, triaxial braiding and through-the-thickness stitching are the three textile processes that have surfaced as the most promising for further development. Textile reinforced composite structural elements that have been developed in the NASA ACT Program are discussed. Included are braided fuselage frames and window-belt reinforcements, woven/stitched lower fuselage side panels, stitched multiaxial warp knit wing skins, and braided wing stiffeners. In addition, low-cost processing concepts such as resin transfer molding (RTM), resin film infusion (RFI), and vacuum-assisted resin transfer molding (VARTM) are discussed. Process modeling concepts to predict resin flow and cure in textile preforms are also discussed.

Fitness level and body composition indices: cross-sectional study among Malaysian adolescent.

Science.gov (United States)

Hanifah, Redzal Abu; Majid, Hazreen Abdul; Jalaludin, Muhammad Yazid; Al-Sadat, Nabilla; Murray, Liam J; Cantwell, Marie; Su, Tin Tin; Nahar, Azmi Mohamed

2014-01-01

The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices. 1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness. 43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age.

Photoluminescence study on amino functionalized dysprosium oxide-zinc oxide composite bifunctional nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Joseph, Aswathy; Praveen, G.L; Abha, K.; Lekha, G.M [Department of Chemistry, University of Kerala, Kariavattom, Kerala 695581 (India); George, Sony, E-mail: emailtosony@gmail.com [Department of Chemistry, University of Kerala, Kariavattom, Kerala 695581 (India)

2012-08-15

An organic dispersion of 9-15 nm size stable dysprosium oxide incorporated zinc oxide nanocomposites exhibiting luminescence in the visible region has been synthesised by a wet chemical precipitation technique at room temperature. Tetraethoxysilane TEOS [(C{sub 2}H{sub 5}O){sub 4}Si], (3-aminopropyl) trimethoxysilane (APTS) and a 1:1 mixture of TEOS-APTS have been used as capping agents to control the particle size as well as to achieve uniform dispersion of composite nanoparticles in methanol medium. X-ray diffractometer (XRD) analysis reveals the formation phase of amino-functionalised colloidal dysprosium oxide incorporated ZnO composite nanoparticles to be of zincite structure. The Transmission Electron Microscopy (TEM) images show that the particles are spheroids in shape, having average crystalline sizes ranging from 9 to 15 nm. The photoluminescence (PL) observed in these composites has been attributed to the presence of near band edge excitonic emission and existence of defect centres. The time correlated single photon counting studies of the composite nanoparticles exhibited three decay pathways. The enhanced PL emission intensity of solid state fluorescence spectra of samples is attributed to the absence of vibrational relaxation process. - Highlights: Black-Right-Pointing-Pointer Nano-composites are synthesised using a one step wet chemical precipitation method. Black-Right-Pointing-Pointer A significant fluorescence life time of 8.25 ns is obtained for the nano-composite. Black-Right-Pointing-Pointer Nano-composite particles exhibited pale yellow fluorescence rather than blue. Black-Right-Pointing-Pointer Vibrational cascade free enhanced fluorescence is obtained for the dry sample.

Feasibility study on development of metal matrix composite by microwave stir casting

Science.gov (United States)

Lingappa, S. M.; Srinath, M. S.; Amarendra, H. J.

2018-04-01

Need for better service oriented materials has boosted the demand for metal matrix composite materials, which can be developed to have necessary properties. One of the most widely utilized metal matrix composite is Al-SiC, which is having a matrix made of aluminium metal and SiC as reinforcement. Lightweight and conductivity of aluminium, when combined with hardness and wear resistance of SiC provides an excellent platform for various applications in the field of electronics, automotives, and aerospace and so on. However, uniform distribution of reinforcement particles is an issue and has to be addressed. The present study is an attempt made to develop Al-SiC metal matrix composite by melting base metal using microwave hybrid heating technique, followed by addition of reinforcement and stirring the mixture for obtaining homogenous mixture. X-Ray Diffraction analysis shows the presence of aluminium and SiC in the cast material. Further, microstructural study shows the distribution of SiC particles in the grain boundaries.

The influence of day/night cycles on biomass yield and composition of Neochloris oleoabundans

NARCIS (Netherlands)

Winter, de Lenneke; Dominguez Teles, Iago; Martens, Dirk E.; Wijffels, René H.; Barbosa, Maria J.

2017-01-01

Background: Day/night cycles regulate the circadian clock of organisms to program daily activities. Many species of microalgae have a synchronized cell division when grown under a day/night cycle, and synchronization might influence biomass yield and composition. Therefore, the aim of this study

Compaction study of particulate iron-chromium matrix composite reinforced with alumina

International Nuclear Information System (INIS)

Saidatulakmar Shamsuddin; Shamsul Baharin Jamaludin; Zuhailawati Hussain; Zainal Arifin Ahmad

2007-01-01

Recently, a sharper focus on cost reduction in producing advanced composites systems has increased and leads to an interest in ferrous matrix composite which is cheaper compared to Cobalt, Nickel and their alloys that are scarce, expensive and their dust is especially harmful. In the present investigation, Fe-Cr-Al 2 O 3 composite was prepared using conventional powder metallurgy technique; mixing, compaction and sintering. Consolidation of particulate materials is dependent on the compaction process. As load is increased, the number of contacting asperities increases and they flatten and grow to form a planar contact surface. These asperities eventually merge to form bonding surfaces between particles. This paper focused on finding the optimum compaction parameter in a uniaxial pressing. Six different pressure were studied; (250, 375, 500, 625, 750 and 875)MPa. experimental results show that the optimum compaction parameter is 750 MPa that produced highest linear shrinkage, highest bulk density, lowest porosity and highest hardness value. Every sample has formed binary alloy of Fe-Cr alloy, confirmed by XRD and alumina are homogeneously distributed in the Fe-Cr matrix revealed by optical micrograph and SEM. from EDX, the composites consist of iron, chromium and alumina. (author)

Neutronic studies of a liquid hydrogen-water composite moderator

International Nuclear Information System (INIS)

Tahara, T.; Ooi, M.; Iwasa, H.; Kiyanagi, Y.; Iverson, E.B.; Crabtree, J.A.; Lucas, A.T.

2001-01-01

A liquid hydrogen-liquid water composite moderator may provide performance like liquid methane at high-power spallation sources where liquid methane is impractical. We have measured the neutronic properties of such a composite moderator, where a hydrogen layer 1.25 cm thick was closely backed by water layers of 1.75 cm and 3.75 cm thickness. We also studied a moderator in which a 1.75 cm water layer was closely backed by a 1.25 cm hydrogen layer. We further performed simulations for each of these systems for comparison to the experimental results. We observed enhancement of the spectral intensity in the 'thermal' energy range as compared to the spectrum from a conventional liquid hydrogen moderator. This enhancement grew more significant as the water thickness increased, although the pulse shapes became wider as well. (author)

Sandia Laboratories environment and safety programs

International Nuclear Information System (INIS)

Zak, B.D.; McGrath, P.E.; Trauth, C.A. Jr.

1975-01-01

Sandia, one of ERDA's largest laboratories, is primarily known for its extensive work in the nuclear weapons field. In recent years, however, Sandia's role has expanded to embrace sizeable programs in the energy, resource recovery, and the environment and safety fields. In this latter area, Sandia has programs which address nuclear, fossil fuel, and general environment and safety issues. Here we survey ongoing activities and describe in more detail aa few projects of particular interest. These range from a study of the impact of sealed disposal of radioactive wastes, through reactor safety and fossil fuel plume chemistry, to investigations of the composition and dynamics of the stratosphere

Studies of local degradation phenomena in composite cathodes for lithium-ion batteries

International Nuclear Information System (INIS)

Kerlau, Marie; Marcinek, Marek; Srinivasan, Venkat; Kostecki, Robert M.

2007-01-01

LiNi 0.8 Co 0.15 Al 0.05 O 2 and LiNi 1/3 Co 1/3 Mn 1/3 O 2 composite cathodes were cycled in model cells to study interfacial phenomena that could lead to electrode degradation. Ex situ spectroscopic analysis of the tested cathodes, which suffered substantial power and capacity loss, showed that the state of charge (SOC) of oxide particles on the cathode surface was highly non-uniform despite the deep discharge of the Li-ion cell at the end of the test. The inconsistent kinetic behavior of individual oxide particles was attributed to the degradation of electronic pathways within the composite cathodes. A simple theoretical model based on a distributed network showed that an increase of the contact resistance between composite electrode particles may be responsible for non-uniform local kinetic behavior of individual oxide particles and the overall degradation of electrochemical performance of composite electrodes

Utilization of ilmenite/epoxy composite for neutrons and gamma rays attenuation

Energy Technology Data Exchange (ETDEWEB)

El-Sayed Abdo, A. E-mail: attiaabdo11@hotmail.com; El-Sarraf, M.A.; Gaber, F.A

2003-01-01

This work deals with the study of ilmenite/epoxy composite as an injecting mortar for cracks developed in biological concrete shields, as well as, neutrons and gamma rays attenuation. Effects of the particle size on the mechanical strengths have been studied for epoxy resin filled with crushed ilmenite with different maximum particle sizes ranging from 32 to 500 {mu}m. Thermal neutrons and gamma rays attenuation in ilmenite/epoxy composites with 75 and 80 wt.% of ilmenite concentration have been investigated. The total mass attenuation coefficients {mu}/{rho} (cm{sup 2} g{sup -1}) of gamma ray for five ilmenite/epoxy composites have been calculated using the XCOM program (version 3.1) at energies from 10 keV to 100 MeV. Also, the total mass attenuation coefficients ({mu}/{rho}) have estimated based on the measured total linear attenuation coefficients ({mu}) and compared with the calculated results where, a reasonable agreement was found.

A national study of the streamflow data-collection program

Science.gov (United States)

Benson, Manuel A.; Carter, Rolland William

1973-01-01

The streamflow data program of the U.S. Geological Survey was evaluated in a nationwide study during 1970. The principal elements of the study were (1) establishing the objectives and goals of the program, (2) analyzing all available data to determine which of the goals have already been met, (3) considering alternate means of meeting the remaining goals, and (4) identifying the elements which should be included in the future program.

Composites Similarity Analysis Method Based on Knowledge Set in Composites Quality Control

OpenAIRE

Li Haifeng

2016-01-01

Composites similarity analysis is an important link of composites review, it can not only to declare composites review rechecking, still help composites applicants promptly have the research content relevant progress and avoid duplication. This paper mainly studies the composites similarity model in composites review. With the actual experience of composites management, based on the author’s knowledge set theory, paper analyzes deeply knowledge set representation of composites knowledge, impr...

Behaviour of steel-concrete composite beams using bolts as shear connectors

Science.gov (United States)

Tran, Minh-Tung; Nguyen Van Do, Vuong; Nguyen, Tuan-Anh

2018-04-01

The paper presents an experimental program on the application of bolts as shear connectors for steel-composite beams. Four steel- concrete composite beams and a reference steel beam were made and tested. The aim of the testing program is to examine which forms of the steel bolts can be used effectively for steel-composite beams. The four types of the bolts include: Type 1 the bolt with the nut at the end; Type 2 the bolt bending at 900 hook; Type 3 the bolt without the nut at the end and Type 4 the bolt with the nut at the end but connected with the steel beam by hand welding in other to be connected with the steel beam by bolt connection as in the first three types. The test results showed that beside the traditional shear connectors like shear studs, angle type, channel type, bolts can be used effectively as the shear connectors in steel-composite beams and the application of bolts in Types 1 and 2 in the composite beams gave the better performance for the tested beam.

A Comprehensive Study on Dielectric Properties of Volcanic Rock/PANI Composites

Science.gov (United States)

Kiliç, M.; Karabul, Y.; Okutan, M.; İçelli, O.

2016-05-01

Basalt is a very well-known volcanic rock that is dark colored and relatively rich in iron and magnesium, almost located each country in the world. These rocks have been used in the refused rock industry, to produce building tiles, construction industrial, highway engineering. Powders and fibers of basalt rocks are widely used of radiation shielding, thermal stability, heat and sound insulation. This study examined three different basalt samples (coded CM-1, KYZ-13 and KYZ-24) collected from different regions of Van province in Turkey. Polyaniline (PANI) is one of the representative conductive polymers due to its fine environmental stability, huge electrical conductivity, as well as a comparatively low cost. Also, the electrical and thermal properties of polymer composites containing PANI have been widely studied. The dielectric properties of Basalt/Polyaniline composites in different concentrations (10, 25, 50 wt.% PANI) have been investigated by dielectric spectroscopy method at the room temperature. The dielectric parameters (dielectric constants, loss and strength) were measured in the frequency range of 102 Hz-106 Hz at room temperature. The electrical mechanism change with PANI dopant. A detailed dielectrically analysis of these composites will be presented.

A Study of Metal-Cement Composites with Additives

Directory of Open Access Journals (Sweden)

Mironov Victor

2014-12-01

Full Text Available The application of small-sized metal fillers (SMF provides a combination of high bulk density, increased durability and ferromagnetic properties of composite materials on the cement basis. However, the total strength of the composite can be compromised by poor adhesion of metal particles with the cement matrix. The use of versatile additives like microsilica and metakaolin is able to improve the structural integrity and mechanical properties of heavy concretes. The paper considers the results of a study using specimens of heavy concretes with SMF aiming to estimate its strength, structural features and ultrasonic parameters. It was found that the contact of SMF particles with the cement was not perfect, since the voids appeared between them and the cement matrix during the cement hydration process (exothermal reaction. Due to the border porosity, the specimens with the metal fillers have lower compressive strength, lower ultrasound velocity and increased frequency slope of attenuation. Microsilica and metakaolin additives facilitate better contact zone between the cement matrix and metal fillers.

Chemical composition and strength of dolomite geopolymer composites

Science.gov (United States)

Aizat, E. A.; Al Bakri, A. M. M.; Liew, Y. M.; Heah, C. Y.

2017-09-01

The chemical composition of dolomite and the compressive strength of dolomite geopolymer composites were studied. The both composites prepared with mechanical mixer manufactured by with rotor speed of 350 rpm and curing in the oven for 24 hours at 80˚C. XRF analysis showThe dolomite raw materials contain fewer amounts of Si and Al but high Ca in its composition. Dolomite geopolymer composites with 20M of NaOH shows greater and optimum compressive strength compared to dolomite geopolymer with other NaOH molarity. This indicated better interaction of dolomite raw material and alkaline activator need high molarity of NaOH in order to increase the reactivity of dolomite.

A comparative study of European nuclear energy programs

Energy Technology Data Exchange (ETDEWEB)

Presas i Puig, Albert [ed.

2011-07-01

The report includes the following contributions: Comparative study of European Nuclear Energy Programs. From international cooperation to the failure of a national program: the Austrian case. The ''go-and-stop'' of the Italian civil nuclear programs, among improvisations, ambitions and conspiracy. Nuclear energy in Spain - a research agenda for economic historians. The Portuguese nuclear program: a peripheral experience under dictatorship (1945-1973). The nuclear energy programs in Switzerland. The rise and decline of an independent nuclear power industry in Sweden, 1945-1970. The German fast breeder program, a historical review. Fast reactors as future visions - the case of Sweden. Transnational flows of nuclear knowledge between the U.S. and the U.K. and continental Europe in the 1950/60s. The Carter administration and its non-proliferation policies: the road to INFCE.

Flight service evaluation of an advanced composite empennage component on commercial transport aircraft. Phase 1: Engineering development

Science.gov (United States)

Ary, A.; Axtell, C.; Fogg, L.; Jackson, A.; James, A. M.; Mosesian, B.; Vanderwier, J.; Vanhamersveld, J.

1976-01-01

The empennage component selected for this program is the vertical fin box of the L-1011 aircraft. The box structure extends from the fuselage production joint to the tip rib and includes the front and rear spars. Various design options were evaluated to arrive at a configuration which would offer the highest potential for satisfying program objectives. The preferred configuration selected consists of a hat-stiffened cover with molded integrally stiffened spars, aluminum trussed composite ribs, and composite miniwich web ribs with integrally molded caps. Material screening tests were performed to select an advanced composite material system for the Advanced Composite Vertical Fin (ACFV) that would meet the program requirements from the standpoint of quality, reproducibility, and cost. Preliminary weight and cost analysis were made, targets established, and tracking plans developed. These include FAA certification, ancillary test program, quality control, and structural integrity control plans.

Microstructural and thermal study of Al-Si-Mg/melon shell ash particulate composite

Directory of Open Access Journals (Sweden)

M. Abdulwahab

Full Text Available The microstructural study via scanning electron microscope (SEM and thermal study via differential scanning calorimetric (DSC study of Al-7%Si-0.3Mg/melon shell ash particulate composite has been carried out. The melon shell ash was used in the production of MMC ranging from 5% to 20% at interval of 5% addition using stir casting method. The melon shell ash was characterized using X-ray fluorescent (XRF that reveal the presence of CaO, SiO2, Al2O3, MgO, and TiO2 as major compounds. The composite was machined and subjected to heat treatment. Microstructural analyses of the composite produced were done using scanning electron microscope (SEM. The microstructure obtained reveals a dark ceramic (reinforcer and white metallic phase. Equally, the 5 wt% DSC result gives better thermal conductivity than other proportions (10 wt%, 15 wt%, and 20 wt%. These results showed that an improved property of Al-Si-Mg alloy was achieved using melon shell ash particles as reinforcement up to a maximum of 20 wt% for microstructural and 5% wt DSC respectively. Keywords: Microstructural analysis, Melon shell ash, Stir casting, X-ray fluorescent, Reinforcement, Composite

Critical joints in large composite primary aircraft structures. Volume 1: Technical summary

Science.gov (United States)

Bunin, Bruce L.

1985-01-01

A program was conducted at Douglas Aircraft Company to develop the technology for critical joints in composite wing structure that meets all the design requirements of a 1990 commercial transport aircraft. In fulfilling this objective, analytical procedures for joint design and analysis were developed during Phase 1 of the program. Tests were conducted at the element level to supply the empirical data required for methods development. Large composite multirow joints were tested to verify the selected design concepts and for correlation with analysis predictions. The Phase 2 program included additional tests to provide joint design and analysis data, and culminated with several technology demonstration tests of a major joint area representative of a commercial transport wing. The technology demonstration program of Phase 2 is discussed. The analysis methodology development, structural test program, and correlation between test results and analytical strength predictions are reviewed.

Vertical circulation and thermospheric composition: a modelling study

OpenAIRE

H. Rishbeth; I. C. F. Müller-Wodarg; I. C. F. Müller-Wodarg

1999-01-01

The coupled thermosphere-ionosphere-plasmasphere model CTIP is used to study the global three-dimensional circulation and its effect on neutral composition in the midlatitude F-layer. At equinox, the vertical air motion is basically up by day, down by night, and the atomic oxygen/molecular nitrogen [O/N2] concentration ratio is symmetrical about the equator. At solstice there is a summer-to-winter flow of air, with downwelling at subauroral latitudes in winter that produc...

Knowledge ecologies, "supple" objects, and different priorities across women's and gender studies programs and departments in the United States, 1970-2010.

Science.gov (United States)

Wood, Christine Virginia

2015-01-01

This article examines the evolving connections between local conditions and knowledge processes in women's and gender studies, a research field in the social sciences and humanities. Data are historical records from five early-adopting women's and gender studies units in the United States and interviews with affiliated professors. In their formative years, these programs were consistent in their intellectual content. Scholars across sites defined the purpose of women's studies similarly: to address the lack of research on women and social problems of sex inequality. Gradually, scholars incorporated a range of analytic categories into women's studies' agenda, including gender identities and masculinities, leading to diverse understandings and redefinitions of the central objects of analysis. Analytic shifts are reflected in differences in the institutional and intellectual composition of programs and departments. To explain how local departmental conditions affect the conception of core objects of study in gender research, the author builds on the literature on knowledge ecologies and introduces the concept of the "supple object." © 2015 Wiley Periodicals, Inc.

[Comparative studies on fissure sealing: composite versus Cermet cement].

Science.gov (United States)

Hickel, R; Voss, A

1989-06-01

Fifty two molars sealed with either composite or Cermet cement were compared. The composite sealant was applied after enamel etching using a rubber dam. Before sealing with Cermet cement the enamel was only cleaned with pumice powder and sodium hypochlorie and the material was applied without enamel etching. After an average follow-up of 1.6 years composite sealants proved to be significantly more reliable. Cermet cement sealings showed defects more frequently.

Study of fatigue crack propagation in laminated metal composites alluminium 1100/alluminium 2024

International Nuclear Information System (INIS)

Tavares, R.I.

1984-01-01

A study has been made of fatigue crack propagation in laminated metal composites with different volume fraction of constituents. The composites were produced by hot rolling, combining 1100 and 2024 aluminum alloys in crack divider orientation. Mechanical and metallurgical properties of the composites and original alloys sheets have been evaluated. Paris type relationship, corresponding to stage II of fatigue crack propagation curves, has been determined by two different methods, wich have shown to be equivalent. A computer software in FORTRAN language was developed for all the mathematical manipulation of fatigue data including statistical analysis and graphics. (Author) [pt

Studies of PVC/ENR blends: blend compositions

International Nuclear Information System (INIS)

Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan; Nasir, M.; Baharin, A.

2002-01-01

Blends of poly(vinyl chloride/epoxidized natural rubber (PVC/ENR) were prepared by using Bra bender Plasticorder at compositions ranging from 0-100% PVC. They were blended at 150 degree C mixing temperature, 50 rpm rotor speed and 10 minutes mixing time. The blends were characterized for tensile strength , elongation at break, glass transition temperatures and Fourier transform infra red spectroscopy (FTIR). Results revealed that as the PVC content increases the blend behaviour changes from elastomeric to glassy. However the blends found to be compatible at all compositions. (Author)

Study of PP/montmorillonite composite degradation

International Nuclear Information System (INIS)

Baer, Marcia; Granado, Carlos J.F.

2009-01-01

The objective of this work was to produce composites of PP/sodium bentonite and PP/ organophilic bentonite through melt intercalation and analyze the degradation produced by ultraviolet irradiation. The XRD results showed that the samples of nature bentonite had better interaction with de polymer and produced intercalated nanocomposite. The effect of UV irradiation on degradation was observed after 24 hours of exposition. The samples showed the same photoproducts and at the same proportion until 240 hours of UV exposition; with 480 hours the organophilize bentonite composite showed higher degradation than other ones. The superficial cracks increased with degradation time. The degradation occurs due chromophores impurities presented in the samples, thus samples with sodium clay show higher degradation, and organophilic clay contains ammonium salt that contribute to increase the degradation. (author)

Prediction of Protein Submitochondrial Locations by Incorporating Dipeptide Composition into Chou's General Pseudo Amino Acid Composition.

Science.gov (United States)

Ahmad, Khurshid; Waris, Muhammad; Hayat, Maqsood

2016-06-01

Mitochondrion is the key organelle of eukaryotic cell, which provides energy for cellular activities. Submitochondrial locations of proteins play crucial role in understanding different biological processes such as energy metabolism, program cell death, and ionic homeostasis. Prediction of submitochondrial locations through conventional methods are expensive and time consuming because of the large number of protein sequences generated in the last few decades. Therefore, it is intensively desired to establish an automated model for identification of submitochondrial locations of proteins. In this regard, the current study is initiated to develop a fast, reliable, and accurate computational model. Various feature extraction methods such as dipeptide composition (DPC), Split Amino Acid Composition, and Composition and Translation were utilized. In order to overcome the issue of biasness, oversampling technique SMOTE was applied to balance the datasets. Several classification learners including K-Nearest Neighbor, Probabilistic Neural Network, and support vector machine (SVM) are used. Jackknife test is applied to assess the performance of classification algorithms using two benchmark datasets. Among various classification algorithms, SVM achieved the highest success rates in conjunction with the condensed feature space of DPC, which are 95.20 % accuracy on dataset SML3-317 and 95.11 % on dataset SML3-983. The empirical results revealed that our proposed model obtained the highest results so far in the literatures. It is anticipated that our proposed model might be useful for future studies.

The mechanics and biocompatibility characteristics of carbon nanotubes-polyurethane composite membranes:a preliminary study

International Nuclear Information System (INIS)

Dong Sheng; Yuan Zheng; Wu Shengwei; Li Wenxin

2011-01-01

Objective: To discuss the mechanics and biocompatibility characteristics of carbon nanotubes-polyurethane composite membranes. Methods: The mechanics property of carbon nanotubes-polyurethane composite membranes with different carbon nanotubes contents were tested by universal material testing machine. The surface of the membranes was observed by electron microscope when the stent was bent 90 degree. And its cytotoxicity was tested by cultivating study with 7721 cell. The metallic stent that was covered with carbon nanotubes-polyurethane composite membrane by using dip-coating method was inserted in rabbit esophagus in order to evaluate its biocompatibility in vivo. Results: Composite membranes tensile strength (MPa) and elongation at break (%) were 4.62/900, 6.05/730, 8.26/704 and 5.7/450 when the carbon nanotubes contents were 0%, 0.1%, 0.3% and 0.5%, respectively. If the stent was bent at 90 degree, its surface was still smooth without any fractures when it was scanned by electron microscope.Composite membranes had critical cytotoxicity when its carbon nanotubes content was up to 0.5% and 1.0%. No fissure nor degradation of composite membranes occurred at 30 days after composite membrane covered metallic stent was inserted in rabbit esophagus. Conclusion: When moderate carbon nanotubes are added into polyurethane composite membrane, the mechanics and biocompatibility characteristics of the polyurethane composite membrane can be much improved. (authors)

A Practical Ethnic Studies Program

Science.gov (United States)

Lum, Lydia

2009-01-01

This article describes the Asian American Studies Program at the University of Massachusetts (UMass) Boston which complements students' career tracks and engages them in the surrounding Asian American community. For many educators, large numbers of graduates are not only a bragging right, but a goal. However, those involved in the Asian American…

An Integrated, Layered-Spinel Composite Cathode for Energy Storage Applications

Science.gov (United States)

Hagh, Nader; Skandan, Ganesh

2012-01-01

At low operating temperatures, commercially available electrode materials for lithium-ion batteries do not fully meet the energy and power requirements for NASA fs exploration activities. The composite cathode under development is projected to provide the required energy and power densities at low temperatures and its usage will considerably reduce the overall volume and weight of the battery pack. The newly developed composite electrode material can provide superior electrochemical performance relative to a commercially available lithium cobalt system. One advantage of using a composite cathode is its higher energy density, which can lead to smaller and lighter battery packs. In the current program, different series of layered-spinel composite materials with at least two different systems in an integrated structure were synthesized, and the volumetric and gravimetric energy densities were evaluated. In an integrated network of a composite electrode, the effect of the combined structures is to enhance the capacity and power capabilities of the material to levels greater than what is possible in current state-of-the-art cathode systems. The main objective of the current program is to implement a novel cathode material that meets NASA fs low temperature energy density requirements. An important feature of the composite cathode is that it has at least two components (e.g., layered and spinel) that are structurally integrated. The layered material by itself is electrochemically inactive; however, upon structural integration with a spinel material, the layered material can be electrochemically activated, thereby delivering a large amount of energy with stable cycling. A key aspect of the innovation has been the development of a scalable process to produce submicronand micron-scale particles of these composite materials. An additional advantage of using such a composite electrode material is its low irreversible loss (.5%), which is primarily due to the unique activation

Characterization and manufacture of braided composites for large commercial aircraft structures

Science.gov (United States)

Fedro, Mark J.; Willden, Kurtis

1992-01-01

Braided composite materials, one of the advanced material forms which is under investigation in Boeing's ATCAS program, have been recognized as a potential cost-effective material form for fuselage structural elements. Consequently, there is a strong need for more knowledge in the design, manufacture, test, and analysis of textile structural composites. The overall objective of this work is to advance braided composite technology towards applications to a large commercial transport fuselage. This paper summarizes the mechanics of materials and manufacturing demonstration results which have been obtained in order to acquire an understanding of how braided composites can be applied to a commercial fuselage. Textile composites consisting of 1D, 2D triaxial, and 3D braid patterns with thermoplastic and two RTM resin systems were investigated. The structural performance of braided composites was evaluated through an extensive mechanical test program. Analytical methods were also developed and applied to predict the following: internal fiber architectures, stiffnesses, fiber stresses, failure mechanisms, notch effects, and the entire history of failure of the braided composites specimens. The applicability of braided composites to a commercial transport fuselage was further assessed through a manufacturing demonstration. Three foot fuselage circumferential hoop frames were manufactured to demonstrate the feasibility of consistently producing high quality braided/RTM composite primary structures. The manufacturing issues (tooling requirements, processing requirements, and process/quality control) addressed during the demonstration are summarized. The manufacturing demonstration in conjunction with the mechanical test results and developed analytical methods increased the confidence in the ATCAS approach to the design, manufacture, test, and analysis of braided composites.

A numerical study of the influence of microvoids in the transverse mechanical response of unidirectional composites

DEFF Research Database (Denmark)

Ashouri Vajari, Danial; González, Carlos; Llorca, Javier

2014-01-01

The effect of porosity on the transverse mechanical properties of unidirectional fiber-reinforced composites is studied by means of computational micromechanics. The composite behavior is simulated by the finite element analysis of a representative volume element of the composite microstructure...... that porosity (in the range 1-5%) led to a large reduction in the transverse strength and the influence of both types of voids in the onset and propagation of damage throughout the microstructure was studied under transverse tension and compression. Finally, the failure locus of the composite lamina under...... transverse tension/compression and out-of-plane shear was obtained by means of computational micromechanics and compared with the predictions of Puck's model and with experimental data available in the literature. The results show that the strength of composites is significantly reduced by the presence...

Study of chloride ion transport of composite by using cement and starch as a binder

Energy Technology Data Exchange (ETDEWEB)

Armynah, Bidayatul; Halide, Halmar; Zahrawani,; Reski, Nurhadi; Tahir, Dahlang, E-mail: dtahir@fmipa.unhas.ac.id [Department of Physics, Hasanuddin University, Makassar 90245 Indonesia (Indonesia)

2016-03-11

This study presents the chemical bonding and the structural properties of composites from accelerator chloride test migration (ACTM). The volume fractions between binder (cement and starch) and charcoal in composites are 20:80 and 60:40. The effect of the binder to the chemical composition, chemical bonding, and structural properties before and after chloride ion passing through the composites was determined by X-ray fluorescence (XRF), by Fourier transform infra-red (FTIR), and x-ray diffraction (XRD), respectively. From the XRD data, XRF data, and the FTIR data shows the amount of chemical composition, the type of binding, and the structure of composites are depending on the type of binder. The amount of chloride migration using starch as binder is higher than that of cement as a binder due to the density effects.

Study on durability of natural fibre concrete composites using ...

Indian Academy of Sciences (India)

33, No. 6, December 2010, pp. 719–729. * Indian Academy of Sciences. 719 ... vegetable fibre–cement composites. ... modified vegetable fibre–mortar composites was analysed ... exhibit better performance than conventional concrete.

Composite resin reinforced with pre-tensioned fibers: a three-dimensional finite element study on stress distribution.

Science.gov (United States)

Jie, Lin; Shinya, Akikazu; Lassila, Lippo V J; Vallittu, Pekka K

2013-01-01

Pre-tensioned construction material is utilized in engineering applications of high strength demands. The purpose of this study was to evaluate the effect of the pre-tensioning fibers of fiber-reinforced composite (FRC) using three-dimensional finite element (FE) analysis. The 3D FE models of particulate composite resin (CR), FRC and composite resin reinforced with pre-tensioned fibers (PRE-T-FRC) were constructed. The uniaxial three-point bending test was simulated using FE analysis to calculate the principal stress distribution. In the FRC and PRE-T-FRC, stresses were higher than CR, and they were located in the fiber. However, the maximum principal stress value at the composite of PRE-T-FRC was lower than the FRC and CR. Composite resin reinforced with pre-tensioned fibers was advantageous for stress distribution and lowering the stress at the composite itself. Experimental studies on physical properties of pre-tensioned FRC are encouraged to be conducted.

Study on an Improved Phosphate Cement Binder for the Development of Fiber-Reinforced Inorganic Polymer Composites

Directory of Open Access Journals (Sweden)

Zhu Ding

2014-11-01

Full Text Available Magnesium phosphate cement (MPC has been proven to be a very good repair material for deteriorated concrete structures. It has excellent adhesion performance, leading to high bonding strength with old concrete substrates. This paper presents an experimental study into the properties of MPC binder as the matrix of carbon fiber sheets to form fiber-reinforced inorganic polymer (FRIP composites. The physical and mechanical performance of the fresh mixed and the hardened MPC paste, the bond strength of carbon fiber sheets in the MPC matrix, the tensile strength of the carbon FRIP composites and the microstructure of the MPC matrix and fiber-reinforced MPC composites were investigated. The test results showed that the improved MPC binder is well suited for developing FRIP composites, which can be a promising alternative to externally-bonded fiber-reinforced polymer (FRP composites for the strengthening of concrete structures. Through the present study, an in-depth understanding of the behavior of fiber-reinforced inorganic MPC composites has been achieved.

Study of a composite from reactive blending of methylol urea resin ...

African Journals Online (AJOL)

This study was designed to study some physical properties of a composite derivable from reactive blending of methylol urea resin (MUR) with natural rubber (NR). Formaldehyde emission, decreased with increase in NR concentration in the blend. Elongation at break and viscosity recorded an initial increase but gradually ...

Study on Cr(VI) Leaching from Cement and Cement Composites

Science.gov (United States)

Palascakova, Lenka; Kanuchova, Maria

2018-01-01

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

Compositional study of the Themis family

Science.gov (United States)

Marsset, Michael; Vernazza, Pierre; Birlan, Mirel; DeMeo, Francesca; Binzel, Richard P.; Dumas, Christophe; Milli, Julien; Popescu, Marcel

2015-11-01

.Assuming particle sizes (typically sub- to micrometer sizes) and end-members composition similar to those found in chondritic porous IDPs, we modeled the spectral properties of the Themis family members. The results of this study will be presented in details.

Study of composition and properties of pentavalenct actinoid carbonates

Energy Technology Data Exchange (ETDEWEB)

Volkov, Yu F; Visyashcheva, G I; Kapshukov, I I; Simakin, G A; Yakovlev, G N

1976-01-01

Monocarbonates and dicarbonates of Npsup((4)), Pusup((5)), and Amsup((5)) with cations Na/sup +/, K/sup +/, and NH/sub 4//sup +/ have been synthesized. The compounds have the following composition: KXO/sub 2/CO/sub 3/xnH/sub 2/O and NH/sub 4/NpO/sub 2/CO/sub 3/xnH/sub 3/O, where x=Np, Pu, or Am; n (<=) 2. They have been studied chemically, thermogravimetrically and by X-ray diffraction method. It has been established that monocarbonates have a hexagonal structure and complex composition corresponding to the formula MXO/sub 2/CO/sub 3/xnH/sub 2/O with a zeolite nature of water molecules. Thermal stability of dicarbonates within the temperature range 20-500/sup 0/C has been studied. An effect of hydration and dehydration on a change in the lattice parameters has been investigated. The data are given on separation, identification, and properties of some sodium carbonatoneptunailates which differ in their physico-chemical properties from other monocarbonates. The main distinctive feature is th eir ability to lose and accept water molecules readily, forming different hydrate forms.

Advanced powder metallurgy aluminum alloys and composites

Science.gov (United States)

Lisagor, W. B.; Stein, B. A.

1982-01-01

The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

Identification of "ever-cropped" land (1984-2010) using Landsat annual maximum NDVI image composites: Southwestern Kansas case study.

Science.gov (United States)

Maxwell, Susan K; Sylvester, Kenneth M

2012-06-01

A time series of 230 intra- and inter-annual Landsat Thematic Mapper images was used to identify land that was ever cropped during the years 1984 through 2010 for a five county region in southwestern Kansas. Annual maximum Normalized Difference Vegetation Index (NDVI) image composites (NDVI(ann-max)) were used to evaluate the inter-annual dynamics of cropped and non-cropped land. Three feature images were derived from the 27-year NDVI(ann-max) image time series and used in the classification: 1) maximum NDVI value that occurred over the entire 27 year time span (NDVI(max)), 2) standard deviation of the annual maximum NDVI values for all years (NDVI(sd)), and 3) standard deviation of the annual maximum NDVI values for years 1984-1986 (NDVI(sd84-86)) to improve Conservation Reserve Program land discrimination.Results of the classification were compared to three reference data sets: County-level USDA Census records (1982-2007) and two digital land cover maps (Kansas 2005 and USGS Trends Program maps (1986-2000)). Area of ever-cropped land for the five counties was on average 11.8 % higher than the area estimated from Census records. Overall agreement between the ever-cropped land map and the 2005 Kansas map was 91.9% and 97.2% for the Trends maps. Converting the intra-annual Landsat data set to a single annual maximum NDVI image composite considerably reduced the data set size, eliminated clouds and cloud-shadow affects, yet maintained information important for discriminating cropped land. Our results suggest that Landsat annual maximum NDVI image composites will be useful for characterizing land use and land cover change for many applications.

Body Composition, Sarcopenia, and Suicidal Ideation in Elderly Koreans: Hallym Aging Study.

Science.gov (United States)

Kim, Jeong-Hyeon; Kim, Dong-Hyun; Park, Yong Soon

2016-04-01

This study was conducted to assess the relationship between body composition and suicidal ideation among the Korean elderly population (n = 302; ≥ 65 years) who participated in the Hallym Aging Study in 2010. Body composition was measured using dual-energy X-ray absorptiometry, and obesity was measured by the indices of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), and body fat percentage. Sarcopenia was defined as presence of both low muscle mass and low muscle function. Suicidal ideation was assessed using the Beck Scale for Suicide Ideation. We found no differences in body composition measures between subjects with suicidal ideation and those without. In the logistic regression analyses, there were no significant relationships for suicidal ideation according to body composition measures, including BMI, WC, WHR, WHtR, and body fat percentage in both sexes. After adjusting for age, smoking status, alcohol drinking, regular exercise, medical comorbidities, monthly income, education level, and presence of depressive symptoms, the odds ratio (OR) of suicidal ideation was higher in elderly men with sarcopenia compared to those without, whereas no significant relationships were observed in elderly women (OR 8.28, 95% confidence interval [CI] 1.20-61.34 in men; OR 0.79, 95% CI 0.07-8.43 in women). Sarcopenia is closely associated with an increased risk of suicidal ideation in elderly men.

A theoretical study of thermospheric composition perturbations during an impulsive geomagnetic storm

International Nuclear Information System (INIS)

Burns, A.G.; Killeen, T.L.; Roble, R.G.

1991-01-01

The compositional response of the neutral thermosphere to an impulsive geomagnetic storm has been investigated using a numerical simulation made with the National Center for Atmospheric Research thermospheric general circulation model (NCAR-TGCM). Calculated time-dependent changes in neutral thermospheric composition have been studied, together with detailed neutral parcel trajectories and other diagnostic information from the model, to gain a greater understanding of the physical mechanisms responsible for composition variability during geomagnetic storms and, in particular, to investigate the causes of the positive and negative ionospheric storm effects. The following principal results were obtained from this study. (1) Calculated perturbations in thermospheric composition following the onset of an impulsive geomagnetic storm were found to be in good qualitative agreement with the previous experimental statistical study of storm time thermospheric morphology by Proelss. (2) During the initial (onset) phase of the simulated storm, upward vertical winds occurred in the auroral zone and downward winds occurred in the central magnetic polar cap. (3) The largest perturbations in mass mixing ratio of nitrogen at F region altitudes were found to be associated with parcels of neutral gas that travelled through the cusp region and with parcels that were trapped within the auroral zone for a long time. (4) Storm time enhancements in Ψ N 2 were found to occur in the midnight and early morning sectors both within and equatorward of the auroral zone, and these were determined to be associated with the advective effects of the large antisunward polar cap neutral winds

Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

Science.gov (United States)

Suhaily, M.; Hassan, C. H. Che; Jaharah, A. G.; Azmi, H.; Afifah, M. A.; Khairusshima, M. K. Nor

2018-04-01

In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites.

A revolutionary approach to composite construction and flight management systems for small, general aviation airplanes

Science.gov (United States)

Roskam, Jan; Wenninger, ED

1992-01-01

The design studies for two composite general aviation airplanes are presented. The main consideration for both of the designs was to avoid the typical 'metal replacement' philosophy that has hindered the widespread use of composites in general aviation aircraft. The first design is for a low wing aircraft based on the Smith Aircraft Corporation GT-3 Global Trainer. The second aircraft is a composite version of the Cessna 152. The project was conducted as a graduate level design class under the auspices of the KU/NASA/USRA Advanced Design Program in aeronautics. The results obtained from the Fall semester of 1991 and the Spring semester of 1992 are presented.

Multi scale analysis by acoustic emission of damage mechanisms in natural fibre woven fabrics/epoxy composites.

Directory of Open Access Journals (Sweden)

Touchard F.

2010-06-01

Full Text Available This paper proposes to develop an experimental program to characterize the type and the development of damage in composite with complex microstructure. A multi-scale analysis by acoustic emission has been developed and applied to hemp fibre woven fabrics/epoxy composite. The experimental program consists of tensile tests performed on single yarn, neat epoxy resin and composite materials to identify their AE amplitude signatures. A statistical analysis of AE amplitude signals has been realised and correlated with microscopic observations. Results have enabled to identify three types of damage in composites and their associated AE amplitudes: matrix cracking, interfacial debonding and reinforcement damage and fracture. Tracking of these damage mechanisms in hemp/epoxy composites has been performed to show the process of damage development in natural fibre reinforced composites.

[In vitro study with techniques of imaging of the composition of urinary calculi].

Science.gov (United States)

Tellez Martínez-Fornés, M; Burgos Revilla, F J; Sáez Garrido, J C; Soria Descalzo, J; Barbero González, J; Sánchez Corral, J; Minaya Minaya, A; Vallejo Herrador, J

1997-02-01

Pre-treatment knowledge of the lithiasic composition can be useful to design the most appropriate therapeutic scheme for each kind of stone. The relationship between the stone's densitometry information provided by the different imaging techniques, conventional radiology (RX), computerized axial tomography (CAT) and dual energy radiographic densitometry (DO) is analyzed, as well as the elemental composition determined by the microanalysis of fragments obtained post-lithotrity using a scanning electronic microscope (SEM) associated to X-ray dispersion energy (XDE). 60 stones, 12 for each pure composition selected (calcium oxalate mono and dihydro, phosphocarbonate, magnesium ammonium phosphate and uric acid), were studied with XR, CAT and DO and were later subjected to lithofragmentation in vitro. Fragments analysis was carried out post-lithotrity with SEM associated to XDE. The X-ray does not allow to establish the composition of some calculi. CAT quantifies the mineral contents of the oxalocalcic and infective calculi and differentiates the uric acid from the other compositions because the mean density values are under 500 Hounsfield Units. DO evaluates the lithiasic content in phosphocarbonate salts which are structurally similar to bone hydroxyapatite.

Wear study of Al-SiC metal matrix composites processed through microwave energy

Science.gov (United States)

Honnaiah, C.; Srinath, M. S.; Prasad, S. L. Ajit

2018-04-01

Particulate reinforced metal matrix composites are finding wider acceptance in many industrial applications due to their isotropic properties and ease of manufacture. Uniform distribution of reinforcement particulates and good bonding between matrix and reinforcement phases are essential features in order to obtain metal matrix composites with improved properties. Conventional powder metallurgy technique can successfully overcome the limitation of stir casting techniques, but it is time consuming and not cost effective. Use of microwave technology for processing particulate reinforced metal matrix composites through powder metallurgy technique is being increasingly explored in recent times because of its cost effectiveness and speed of processing. The present work is an attempt to process Al-SiC metal matrix composites using microwaves irradiated at 2.45 GHz frequency and 900 W power for 10 minutes. Further, dry sliding wear studies were conducted at different loads at constant velocity of 2 m/s for various sliding distances using pin-on-disc equipment. Analysis of the obtained results show that the microwave processed Al-SiC composite material shows around 34 % of resistance to wear than the aluminium alloy.

[Study on spectroscopic characterization and property of PES/ micro-nano cellulose composite membrane material].

Science.gov (United States)

Tang, Huan-Wei; Zhang, Li-Ping; Li, Shuai; Zhao, Guang-Jie; Qin, Zhu; Sun, Su-Qin

2010-03-01

In the present paper, the functional groups of PES/micro-nano cellulose composite membrane materials were characterized by Fourier transform infrared spectroscopy (FTIR). Also, changes in crystallinity in composite membrane materials were analyzed using X-ray diffraction (XRD). The effects of micro-nano cellulose content on hydrophilic property of composite membrane material were studied by measuring hydrophilic angle. The images of support layer structure of pure PES membrane material and composite membrane material were showed with scanning electron microscope (SEM). These results indicated that in the infrared spectrogram, the composite membrane material had characteristic peaks of both PES and micro-nano cellulose without appearance of other new characteristics peaks. It revealed that there were no new functional groups in the composite membrane material, and the level of molecular compatibility was achieved, which was based on the existence of inter-molecular hydrogen bond association between PES and micro-nano cellulose. Due to the existence of micro-nano cellulose, the crystallinity of composite membrane material was increased from 37.7% to 47.9%. The more the increase in micro-nano cellulose mass fraction, the better the van de Waal force and hydrogen bond force between composite membrane material and water were enhanced. The hydrophilic angle of composite membrane material was decreased from 55.8 degrees to 45.8 degrees and the surface energy was raised from 113.7 to 123.5 mN x m(-2). Consequently, the hydrophilic property of composite membrane material was improved. The number of pores in the support layer of composite membrane material was lager than that of pure PES membrane. Apparently, pores were more uniformly distributed.

Dating Violence and Sexual Assault Prevention with African American Middle Schoolers: Does Group Gender Composition Impact Dating Violence Attitudes?

Science.gov (United States)

Black, Beverly M.; Weisz, Arlene N.; Jayasundara, Dheeshana S.

2012-01-01

A dating violence and sexual assault prevention program was presented to 396, predominately African American, middle schoolers in two inner city schools in the United States. In one school the program was offered with a same-gender group composition; in the other school, the same program was offered with mixed-gender group composition. A…

Metformin, Lifestyle Intervention, and Cognition in the Diabetes Prevention Program Outcomes Study.

Science.gov (United States)

Luchsinger, José A; Ma, Yong; Christophi, Costas A; Florez, Hermes; Golden, Sherita H; Hazuda, Helen; Crandall, Jill; Venditti, Elizabeth; Watson, Karol; Jeffries, Susan; Manly, Jennifer J; Pi-Sunyer, F Xavier

2017-07-01

We examined the association of the Diabetes Prevention Program (DPP) intervention arms (lifestyle intervention, metformin, and placebo) with cognition in the Diabetes Prevention Program Outcomes Study (DPPOS). We also examined metformin use, incident type 2 diabetes, and glycemia as exposures. The DPP lasted 2.8 years, followed by a 13-month bridge to DPPOS. Cognition was assessed in DPPOS years 8 and 10 (12 and 14 years after randomization) with the Spanish English Verbal Learning Test (SEVLT), letter fluency and animal fluency tests, Digit Symbol Substitution Test (DSST), and a composite cognitive score. A total of 2,280 participants (749 lifestyle, 776 metformin, and 755 placebo) aged 63.1 ± 10.7 years underwent cognitive assessments; 67.7% women, 54.6% non-Hispanic white, 20.7% non-Hispanic black, 14.6% Hispanic, 5.5% American Indian, and 4.6% Asian; 26.6% were homozygous or heterozygous for APOE-ε4. At the time of cognitive assessment, type 2 diabetes was higher in the placebo group (57.9%; P cognition across intervention arms. Type 2 diabetes was not related to cognition, but higher glycated hemoglobin at year 8 was related to worse cognition after confounder adjustment. Cumulative metformin exposure was not related to cognition. Exposure to intensive lifestyle intervention or metformin was not related to cognition among DPPOS participants. Higher glycemia was related to worse cognitive performance. Metformin seemed cognitively safe among DPPOS participants. © 2017 by the American Diabetes Association.

Study of electric, magnetic properties and improvements in ME effects of NMFO + BZT particulate composites

Energy Technology Data Exchange (ETDEWEB)

Chavan, Pradeep [Department of Physics, Karnatak University, Dharwad 580003, Karnataka (India); Naik, L.R., E-mail: naik_40@rediffmail.com [Department of Physics, Karnatak University, Dharwad 580003, Karnataka (India); Kotnala, R.K. [National Physical Laboratory, K. S. Krishnan Marg, Pusa, New Delhi 110012 (India)

2017-07-01

ME composite materials with the general formula (x)Ni{sub 0.9}Mg{sub 0.1}Fe{sub 2}O{sub 4} + (1 − x)BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} (x = 0.1, 0.2, 0.3, 0.4 and 0.5) were synthesized by solid state reaction method. X-ray diffraction (XRD) study reveals the coexistence of piezomagnetic and piezoelectric phases without interacting with each other. The cubic spinel structure of Ni{sub 0.9}Mg{sub 0.1}Fe{sub 2}O{sub 4} (NMFO) piezomagnetic phase and tetragonal perovskite structure of BaZr{sub 0.2}Ti{sub 0.8}O{sub 3} (BZT) piezoelectric phase for synthesized composites were confirmed by XRD measurements. The lattice constant of piezomagnetic and piezoelectric phases increases with increase in composition of the substituent. The dielectric constant and dielectric loss tangent of the composites measured as a function of frequency in the range 10 Hz–1 MHz at room temperature are found to decrease rapidly in low frequency regime and remain constant in high frequency regime shows the dielectric dispersion behavior. The magnetic properties of the composites have been studied using M-H hysteresis loops to see the response of the magnetic field on the NMFO phase in the composites. The saturation magnetization increases with increase in the mole% of piezomagnetic phase in the composites. The ME voltage coefficient measured as a function of the applied DC magnetic field; shows maximum value (8.622 mV cm{sup −1} Oe) for (50%)NMFO + (50%)BZT bulk composites. The addition of NMFO and BZT enhances the ME properties of the composites.

The Effects of the Nintendo Wii Exercise Program on Chronic Work-related Low Back Pain in Industrial Workers.

Science.gov (United States)

Park, Ji-Hyuk; Lee, Sang-Heon; Ko, Dae-Sik

2013-08-01

[Purpose] The purpose of this study was to investigate the effects of a Nintendo Wii exercise program on chronic work-related LBP compared with stability exercise. [Methods] Twenty-four workers participated in this study. All of the participants were diagnosed with chronic LBP by a physician. Participants were randomly assigned to three groups: a control group (CG), lumbar stabilization exercise group (LSE), and Nintendo Wii exercise group (NWE). Participants were treated 3 times a week for 8 weeks. Each session lasted 30 minutes. [Results] The results demonstrated that exercise programs improved significantly physical functions related to LBP. In health-related QOL, the Nintendo Wii exercise program significantly improved both the mental and physical health composites, but other groups had significant improvement only in the physical health composite. [Conclusion] The Nintendo Wii exercise program could be a biopsychosocial intervention for work-related LBP in factory workers.

Experimental study on mix proportion of fiber reinforced cementitious composites

Science.gov (United States)

Jia, Yi; Zhao, Renda; Liao, Ping; Li, Fuhai; Yuan, Yuan; Zhou, Shuang

2017-10-01

To study the mechanical property of fiber reinforced cementations composites influenced by the fiber length, quartz sand diameter, matrix of water cement ratio, volume fraction of fiber and magnesium acrylate solution. Several 40×40×160 mm standard test specimens, "8" specimens and long "8" specimens and 21 groups of fiber concrete specimens were fabricated. The flexural, compressive and uniaxial tensile strength were tested by using the bending resistance, compression resistance and electronic universal testing machine. The results show that flexural and compressive strength of fiber reinforced cementations composites increases along with the increase of quartz sand diameter, with the growth of the PVA fiber length increases; When the water-binder ratio is 0.25 and powder-binder ratio is 0.3, the PVA fiber content is 1.5% of the mass of cementations materials, there is a phenomenon of strain hardening; The addition of magnesium acrylate solution reduces the tensile strength of PVA fiber reinforced cementations composites, the tensile strength of the specimens in the curing age of 7d is decreased by about 21% and the specimens in curing age of 28d is decreased by more than 50%.

Analysis of bachelor study programs of nursing at universities of Eastern Slovakia: a pilot study

Directory of Open Access Journals (Sweden)

Gabriela Kuriplachová

2016-07-01

Full Text Available Background: The profile of the nursing studies in Slovakia is harmonized with the criteria of European Directives, enhanced by the adoption of the Declaration of Munich and implemented into the curriculum of educational institutions that provide this traning. Objective: The main objective of the pilot study was to determinate satisfaction of graduates with accredited programs of nursing (prior to the accreditation and after accreditation at two state universities in the eastern region of Slovakia. Methods: The monitored group consisted of total 132 respondents (nursing graduates who completed the 1st degree of nursing study at University of Presov in Presov or University of P. J. Safarik in Kosice in the timeframe 2007-2011. The study was realized during calendar years 2012-2013. One year of nursing clinical practice of graduates was required for this study. Data was collected through a modified questionnaire of feedback used at the University of Presov, Faculty of Health Care within the improvement of curricula program and the whole educational program. Results: Statistically significant differences were observed in area of optional courses of nursing study program (p < 0.05. Compulsory optional courses of nursing program at both universities were more interest and important for clinical practice of graduates after accreditation than before accreditation. Conclusions: The nursing study program meets the educational requirements of European Union. However, study program needs courses, which would be more interesting and effective for clinical practice.

Study of a new X-ray protective apron with composite protective sheet

International Nuclear Information System (INIS)

Kanzaki, Ryuji; Ohtsuka, Akiyoshi; Okayama, Akio

1997-01-01

Lead powder and oxygenated lead are widely used as materials in conventional protective aprons. However, the use of lead alone limits weight reduction in an apron. Because the amount of lead can not be decreased without reducing X-ray absorption rate. In this study, we report the efficiency of a new X-ray protective apron with a composite protective sheet. The X-ray absorption rate of the composite sheet was 4.5 percent less than that of the lead sheet. However, the effective protective efficiency of the composite sheet was the same as that of the lead sheet. The uniformity of the new X-ray protective apron was good, and the differences among products were small. The new X-ray protective apron was about 30 percent lighter than a lead apron with a 0.25 mm lead equivalent. The new lighter aprons are more comfortable for the radiology staff. Therefore, the use of a composite protective apron provides the advantages of weight reduction and increased comfort without reducing X-ray absorption rate. (author)

Compassion and Caring: Missing Concepts in Social Studies Programs.

Science.gov (United States)

Oliner, Pearl

1979-01-01

Current social studies programs do not include the study of prosocial behaviors such as altruism, generosity, and compassion. This omission legitimizes the view that human behaviors are self-serving. Curriculum developers should fashion programs which provide prosocial models and opportunities for students to conceptualize such behaviors and…

A Competence-Based Curriculum Design for Entrepreneurship Study Program

Directory of Open Access Journals (Sweden)

Priska J.R. Siagian

2011-08-01

Full Text Available Indonesia is affected by global crisis. Increasing the number of entrepreneurs is one of many solutions to increase the economic growth in Indonesia. The number of entrepreneurs in Indonesia to leverage the economic growth is still limited. Entrepreneurs can be prepared through an Entrepreneurship Study Program. Entrepreneurship Study Program attempts to create qualified entrepreneurs who have relevant competences. In order to create a qualified entrepreneurs, the Entrepreneurial Studies Program requires a competency-based curriculum that will support the educational process and provide all the necessary to become future entrepreneurs who can survive through a global challenge. This research aims to design a competence-based curriculum for entrepreneurial study and uses Quality Function Deployment (QFD as the major tool to design the competence-based curriculum. From the QFD process, this research finds core and elective courses for the Entrepreneurship Study Program. The result shows the competences covered by the courses and sequence, credits, and teaching methods for each course. The competences prepared the potential entrepreneurs can be achieved through specific courses which can be acquired within 8 semesters.

Cooled Ceramic Matrix Composite Propulsion Structures Demonstrated

Science.gov (United States)

Jaskowiak, Martha H.; Dickens, Kevin W.

2005-01-01

NASA's Next Generation Launch Technology (NGLT) Program has successfully demonstrated cooled ceramic matrix composite (CMC) technology in a scramjet engine test. This demonstration represented the world s largest cooled nonmetallic matrix composite panel fabricated for a scramjet engine and the first cooled nonmetallic composite to be tested in a scramjet facility. Lightweight, high-temperature, actively cooled structures have been identified as a key technology for enabling reliable and low-cost space access. Tradeoff studies have shown this to be the case for a variety of launch platforms, including rockets and hypersonic cruise vehicles. Actively cooled carbon and CMC structures may meet high-performance goals at significantly lower weight, while improving safety by operating with a higher margin between the design temperature and material upper-use temperature. Studies have shown that using actively cooled CMCs can reduce the weight of the cooled flow-path component from 4.5 to 1.6 lb/sq ft and the weight of the propulsion system s cooled surface area by more than 50 percent. This weight savings enables advanced concepts, increased payload, and increased range. The ability of the cooled CMC flow-path components to operate over 1000 F hotter than the state-of-the-art metallic concept adds system design flexibility to space-access vehicle concepts. Other potential system-level benefits include smaller fuel pumps, lower part count, lower cost, and increased operating margin.

Creating texts an introduction to the study of composition

CERN Document Server

Nash, Walter

2014-01-01

Creating Texts emphasises a practical approach to composition and enables students to understand what is involved in the creation of a text and to learn from the practice of other writers. Extensively rewritten and updated from Walter Nash's earlier volume, Designs in Prose, attention is paid to the general theory of composition, in both traditional and original terms, so that students are made familiar with the basic resources of composition, in grammar and in the lexicon.The essence of every chapter is the discussion of examples of text, sometimes devised by the authors

Tensile and Flexural Test on Kenaf Hybrid Composites

Science.gov (United States)

Salleh, Z.; Yunus, S.; Masdek, N. R. N. M.; Taib, Y. M.; Azhar, I. I. S.; Hyie, K. M.

2018-03-01

The widely use of synthetic materials like carbon and fiberglass in various industries such as automotive and aircraft has lead to human health and environment problems. Therefore, the use of natural fibres such as kenaf has received higher attention as reinforcement. Kenaf or the scientific name is Hibiscus Cannabinus. L is one of the group of Malvecea plant which in the early days, the application of kenaf served only rope and canvas. However, it has more advantages than synthetic materials such as; widely availaible, renewable, lightweight, non-abbrasiveness during processing, high specific strength, free from health hazard and biodegradeable. This study was carried out to investigate the effects of different arrangement of kenaf and fiberglass composites on Young’s Modulus. The material composite was hardened with polyester resin and their properties was characterized. The tensile and the flexural properties is determined using an Instron universal tensile testing machine and carried out by following ASTM D3039 for tensile and ASTM D790 for a flexural test. The experimental program was designed to correlate the flexural and tensile Young’s Modulus of kenaf and fiberglass composite under the same load condition but different arrangement of kenaf and fiberglass on the mold . The resistance to change in shape was described by the behavior and characteristic of the composite materials. The stiffness or the elastic modulus of the composite material was determined at the end of the experiment. The results obtained show that the [±90FG/0/90/90/0/±90FG] kenaf/fiberglass composite arrangement has the highest elastic value.

Study of the Mechanical and Morphology Properties of Recycled HDPE Composite Using Rice Husk Filler

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Jia Ying Tong

2014-01-01

Full Text Available WPCs are being used in a large number of applications in the automotive, construction, electronic, and aerospace industries. There are an increasing number of research studies and developments in WPC technology involving rice husk as fillers. This study investigated the effects of different compositions of rice husk (RH filler on the mechanical and morphological properties of recycled HDPE (rHDPE composite. The composites were prepared with five different loading contents of RH fibers (0, 10, 20, 30, and 40 wt% using the twin screw extrusion method. Maleic acid polyethylene (MAPE was added as a coupling agent. Results showed that tensile and flexural properties improved with increasing RH loading. However, the impact strength of the composites decreased as the RH loading increased. SEM micrographs revealed good interfacial bonding between the fiber and polymer matrix.

A comparative study on the properties of graphene oxide and activated carbon based sustainable wood starch composites.

Science.gov (United States)

Baishya, Prasanta; Maji, Tarun Kumar

2018-08-01

Activated carbon (AC) prepared from Jatropha curcas and graphene oxide (GO) were employed in the preparation of natural polymer based wood starch composites (WSC) through the solution blending technique using water as a solvent. In this study, methyl methacrylate (MMA) was grafted onto the starch polymer and this MMA grafted starch (MMA-g-starch) was cross-linked with the cheap soft wood flour using the citric acid as cross-linker and water as a solvent in the whole process. The prepared GO and AC were characterized through Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA) and Raman study. The interaction of GO and AC, with MMA-g-starch, citric acid and wood were studied by FTIR, XRD and SEM analysis. The GO and AC treated composites exhibited outstanding mechanical properties, thermal stability and fire resistance properties. The tensile strength of the composites increased by 178% and 200% with addition of 2 phr AC and GO respectively compared to untreated composites. A significant enhancement in water resistance properties of GO and AC treated composites was also attained. The study showed that the properties of the composites containing AC prepared from the seeds of Jatropha curcas was quite comparable with the composites reinforced with GO. Copyright © 2018 Elsevier B.V. All rights reserved.

Processing, properties and applications of composites using powder-coated epoxy towpreg technology

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Bayha, T. D.; Osborne, P. P.; Thrasher, T. P.; Hartness, J. T.; Johnston, N. J.; Marchello, J. M.; Hugh, M. K.

1993-01-01

Composite manufacturing using the current prepregging technology of impregnating liquid resin into three-dimensionally reinforced textile preforms can be a costly and difficult operation. Alternatively, using polymer in the solid form, grinding it into a powder, and then depositing it onto a carbon fiber tow prior to making a textile preform is a viable method for the production of complex textile shapes. The powder-coated towpreg yarn is stable, needs no refrigeration, contains no solvents and is easy to process into various woven and braided preforms for later consolidation into composite structures. NASA's Advanced Composites Technology (ACT) program has provided an avenue for developing the technology by which advanced resins and their powder-coated preforms may be used in aircraft structures. Two-dimensional braiding and weaving studies using powder-coated towpreg have been conducted to determine the effect of resin content, towpreg size and twist on textile composite properties. Studies have been made to customize the towpreg to reduce friction and bulk factor. Processing parameters have been determined for three epoxy resin systems on eight-harness satin fabric, and on more advanced 3-D preform architectures for the downselected resin system. Processing effects and the resultant mechanical properties of these textile composites will be presented and compared.

Portfolio optimization in enhanced index tracking with goal programming approach

Science.gov (United States)

Siew, Lam Weng; Jaaman, Saiful Hafizah Hj.; Ismail, Hamizun bin

2014-09-01

Enhanced index tracking is a popular form of passive fund management in stock market. Enhanced index tracking aims to generate excess return over the return achieved by the market index without purchasing all of the stocks that make up the index. This can be done by establishing an optimal portfolio to maximize the mean return and minimize the risk. The objective of this paper is to determine the portfolio composition and performance using goal programming approach in enhanced index tracking and comparing it to the market index. Goal programming is a branch of multi-objective optimization which can handle decision problems that involve two different goals in enhanced index tracking, a trade-off between maximizing the mean return and minimizing the risk. The results of this study show that the optimal portfolio with goal programming approach is able to outperform the Malaysia market index which is FTSE Bursa Malaysia Kuala Lumpur Composite Index because of higher mean return and lower risk without purchasing all the stocks in the market index.

Implementing a campus wide recycling program

International Nuclear Information System (INIS)

Alvarez, L.

2002-01-01

'Full text:' The University of Windsor is currently expanding its recycling program to include all buildings on campus, but faces two challenges: 1) uncertainty about the current waste composition and distribution on campus; and 2) uncertainty about the effectiveness of increased recycling. This project assesses the current waste composition and the attitudes of the students towards recycling, and evaluates the effectiveness of proposed recycling activities. At present, paper is the only material that is collected throughout the entire campus. Except for two buildings, all other potentially recyclable materials within buildings, such as metal, glass, and plastic beverage containers, are discarded. The main focus of this research is on beverage containers as they represent clearly identifiable materials, but other materials were examined as well. To quantify the waste, different buildings on campus were classified according to their function: academic,operational and administrative. The waste composition study indicated that approximately 33% of the campus waste which is landfilled is composed of potentially recyclable material. A survey was then conducted to gauge the campus population's views on recycling issues that could affect the design of a recycling program. Interestingly, 97% of the respondents indicated a high willingness to recycle, but were uncertain as to how and where to recycle on campus. The project is currently assessing potential diversion rates using new, clearly identifiable recycling receptacles placed within selected classrooms for all major materials. There is a significant tradeoff however because the cost for new receptacles is considerable: multiple materials containers are often placed in high pedestrian traffic locations (e.g., hallways) and not always in classrooms,of which there are often many. This project will evaluate the basic benefits and costs of implementing a more comprehensive recycling program, and recommend how other

Composite quarterly technical report: long-term high-level waste technology, October-December 1980

International Nuclear Information System (INIS)

Cornman, W.R.

1981-04-01

The technical information in this report summarizes work performed at participating sites to immobilize high-level radioactive wastes. The areas reported are in: program management and support; waste preparation; waste fixation; and final handling. Majority of the studies were in the area of waste fixation, some of which are: leaching tests of ceramic forms, high silica glass, graphite powder and other carbon preparations; viscosity measurements for a range of waste-glass compositions from references borosilicate glass to high-alumina glasses; neutron activation analysis for measuring leach rates; preparation of SYNROC D spheres; formulations for preparing ceramics from defense waste composition; development of a pilot-scale glass melter, and kinetic studies of slag formation in glass melters

Study of Wood Plastic Composites elastic behaviour using full field measurements

Science.gov (United States)

Ben Mbarek, T.; Robert, L.; Hugot, F.; Orteu, J. J.; Sammouda, H.; Graciaa, A.; Charrier, B.

2010-06-01

In this study, the mechanical properties and microstructure of HDPE/wood fibre composites are investigated. The four-point bending and tensile behaviour of Wood Plastic Composite (WPC) with or without additive are studied by using full-field strain measurements by 3-D Digital Image Correlation (3-D DIC). A non-linear behaviour is shown. The modulus of elasticity (MOE) is calculated as the tangent at zero strain of a Maxwell-Bingham model fitted onto experimental data. Four-point bending tests are analyzed thanks to the spatial standard deviation of the longitudinal strain field to determine the degree of heterogeneity. Cyclic tensile tests have been performed in order to analyze the damage of the material. Moreover, Scanning Electron Microscope (SEM) is used to characterize the morphology of the wood fibre/HDPE matrix interface for specimens with maleic anhydride modified polyethylene additive (MAPE).

Thermal Performance Study of Composite Phase Change Material with Polyacrylicand Conformal Coating.

Science.gov (United States)

Kee, Shin Yiing; Munusamy, Yamuna; Ong, Kok Seng; Cornelis Metselaar, Hendrik Simon; Chee, Swee Yong; Lai, Koon Chun

2017-07-28

The composite PCM was prepared by blending polymethyl methacrylate (PMMA) and myristic acid (MA) in different weight percentages. The MA and PMMA were selected as PCM and supporting material, respectively. As liquid MA may leak out during the phase transition, this study proposes the use of two coatings, namely a polyacrylic coating and a conformal coating to overcome the leakage problem. Both coatings were studied in terms of the leakage test, chemical compatibility, thermal stability, morphology, and reliability. No leakage was found in the PCMs with coatings compared to those without under the same proportions of MA/PMMA, thus justifying the use of coatings in the present study. The chemically compatibility was confirmed by FTIR spectra: the functional groups of PCMs were in accordance with those of coatings. DSC showed that the coatings did not significantly change the melting and freezing temperatures, however, they improved the thermal stability of composite PCMs as seen in TGA analysis. Furthermore, the composite PCMs demonstrated good thermal reliability after 1000 times thermal cycling. The latent heat of melting reduced by only 0.16% and 1.02% for the PCMs coated with conformal coating and polyacrylic coating, respectively. Therefore, the proposed coatings can be considered in preparing fatty acid/PMMA blends attributed to the good stability, compatibility and leakage prevention.

Fitness level and body composition indices: cross-sectional study among Malaysian adolescent

Science.gov (United States)

2014-01-01

Background The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices. Methods 1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness. Results 43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p fitness score (r = -0.360, -0.413 and -0.403 for body mass index for age, waist circumference and waist height ratio, respectively). Waist circumference was the strongest and significant predictor for fitness (ß = -0.318, p = 0.002). Conclusion Only 9.6% of the students were fit. There was also an inverse association between body composition and fitness score among apparently healthy adolescents, with waist circumference indicated as the strongest predictor. The low fitness level among the Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age. PMID:25436933

Reading Like a Writer, Teaching Like a Reader: Guiding Students towards "Good Reading" in First-Year Composition

Science.gov (United States)

De Piero, Zack Kramer

2017-01-01

This study examined how graduate students in humanities disciplines guide students' reading during their work as teaching assistants (TAs) in first-year (FYC) composition courses. Situated within an independent writing program, the "genre studies" approach to this FYC course is informed by the threshold concepts of the composition…

Using laser absorption spectroscopy to monitor composition and physical properties of metal vapors

International Nuclear Information System (INIS)

Berzins, L.V.

1993-01-01

The Atomic Vapor Laser Isotope Separation (AVLIS) program has been using laser absorption spectroscopy to monitor vapor densities for over 15 years. Laser absorption spectroscopy has proven itself to be an accurate and reliable method to monitor both density and composition. During this time the diagnostic has moved from a research tool toward a robust component of a process control system. The hardware used for this diagnostic is discussed elsewhere at this symposium. This paper describes how the laser absorption spectroscopy diagnostic is used as a component of a process control system as well as supplying detailed measurements on vapor densities, composition, flow velocity, internal and kinetic temperatures, and constituent distributions. Examples will be drawn from the uranium AVLIS program. In addition potential applications such as composition control in the production of metal matrix composites or aircraft alloys will be discussed

EVALUASI PELAKSANAAN PEMBELAJARAN PROGRAM STUDI DESAIN KOMUNIKASI VISUAL MSD YOGYAKARTA

Directory of Open Access Journals (Sweden)

Soraya Fatmawati

2016-06-01

THE EVALUATION OF INSTRUCTIONAL IMPLEMENTATION OF VISUAL COMMUNICATION DESIGN STUDY PROGRAM IN MSD YOGYAKARTA Abstract This research aims to determine the suitability of the instructional implementation in Visual Communication Design (VCD Study Program of MSD Yogyakarta Design and Art Academy with standard or criteria which have been formulated. This research was an evaluation research study that refers to the discrepancy evaluation model. The subjects consisted of the head of study program, lecturers and students of VCD study program MSD Yogyakarta. The research was conducted in five stages: design preparation, determination of the program’s completeness, data collection, purpose measurement or data analysis, and comparison. Data were collected through observation, interviews, and document searches, and were analyzed using an interactive analysis model proposed by Miles and Huberman. The questionnaire data were analyzed using descriptive statistical analysis in the scale 4. The result of the study shows that instructional implementation in Visual Communication Design Study Program of MSD Yogyakarta is not suitable to the Minister of Education and Culture Regulation No. 49, 2014. The result of student assessment indicates that the instructional implementation in VCD MSD Yogyakarta is categorized good with the value of 3.20. The instructional implementation in Visual Communication Design Study Program of MSD Yogyakarta needs to be adjusted with the National Standards for Higher Education the Minister of Education and Culture Regulation No. 49, 2014 for the instructional implementation can be presented. Keywords: instructional implementation, instructional planning