Development of functionally graded anti-oxidation coatings for carbon/carbon composites

Energy Technology Data Exchange (ETDEWEB)

Jeon, J.H. [Dept. of Materials Technology, Korea Inst. of Machinery and Materials, Changwon (Korea); Fang Hai-Tao; Lai Zhong-Hong; Yin Zhong-Da [Materials Science and Engineering School, Harbin Inst. of Tech., Harbin (China)

2005-07-01

The concept of functionally graded materials (FGMs) was originated in the research field of thermal barrier coatings. Continuous changes in the composition, grain size, porosity, etc., of these materials result in gradients in such properties as mechanical strength and thermal conductivity. In recent years, functionally graded structural composite materials have received increased attention as promising candidate materials to exhibit better mechanical and functional properties than homogeneous materials or simple composite materials. Therefore the research area of FGMs has been expending in the development of various structural and functional materials, such as cutting tools, photonic crystals, dielectric and piezoelectric ceramics, thermoelectric semiconductors, and biomaterials. We have developed functionally graded structural ceramic/metal composite materials for relaxation of thermal stress, functionally graded anti-oxidation coatings for carbon/carbon composites, and functionally graded dielectric ceramic composites to develop advanced dielectric ceramics with flat characteristics of dielectric constant in a wide temperature range. This paper introduces functionally graded coatings for C/C composites with superior oxidation resistance at high temperatures. (orig.)

Comparative thermal buckling analysis of functionally graded plate

Directory of Open Access Journals (Sweden)

Čukanović Dragan V.

2017-01-01

Full Text Available A thermal buckling analysis of functionally graded thick rectangular plates accord¬ing to von Karman non-linear theory is presented. The material properties of the functionally graded plate, except for the Poisson’s ratio, were assumed to be graded in the thickness direction, according to a power-law distribution, in terms of the volume fractions of the metal and ceramic constituents. Formulations of equilibrium and stability equations are derived using the high order shear deformation theory based on different types of shape functions. Analytical method for determination of the critical buckling temperature for uniform increase of temperature, linear and non-linear change of temperature across thickness of a plate is developed. Numeri¬cal results were obtained in МATLAB software using combinations of symbolic and numeric values. The paper presents comparative results of critical buckling tempera¬ture for different types of shape functions. The accuracy of the formulation presented is verified by comparing to results available from the literature.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part three: aerobic exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Mizusaki Imoto, Aline; Toupin-April, Karine; Westby, Marie; Álvarez Gallardo, Inmaculada C; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective aerobic exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, or D-) was used, based on statistical significance ( P osteoarthritis within a 12-week period. An aerobic exercise program demonstrated significant improvement for pain relief (Grade B), physical function (Grade B) and quality of life (Grade C+). Aerobic exercise in combination with strengthening exercises showed significant improvement for pain relief (3 Grade A) and physical function (2 Grade A, 2 Grade B). A short-term aerobic exercise program with/without muscle strengthening exercises is promising for reducing pain, improving physical function and quality of life for individuals with knee osteoarthritis.

Fabrication and laboratory-based performance testing of a building-integrated photovoltaic-thermal roofing panel

International Nuclear Information System (INIS)

Chen, Fangliang; Yin, Huiming

2016-01-01

Highlights: • A BIPVT solar panel is designed and fabricated for energy efficient buildings. • A high-speed manufacture method is developed to produce the functionally graded materials. • Laboratory tests demonstrate BIPVT’s energy efficiency improvement and innovations. • The PV efficiency is enhanced ∼24% through temperature control of the panel by water flow. • The combined electric and thermal efficiency reaches >75% of solar irradiation. - Abstract: A building integrated photovoltaic-thermal (BIPVT) multifunctional roofing panel has been developed in this study to harvest solar energy in the form of PV electricity as well as heat energy through the collection of warm water. As a key component of the multifunctional building envelope, an aluminum/high-density polyethylene (HDPE) functionally graded material (FGM) panel embedded with aluminum water tubes has been fabricated through the vibration-sedimentation approach. The FGM layer gradually transits material phases from well-conductive side (with aluminum dominated) to another highly insulated side (with HDPE). The heat in the PV cells can be easily transferred into the conductive side of the FGM and then collected by the water flow in the embedded tubes. Therefore, the operational temperature of the PV cells can be significantly lowered down, which recovers the PV efficiency in hot weather. In this way, the developed BIPVT panel is able to efficiently harvest solar energy in the form of both PV electricity and heat. The performance of a prototype BIPVT panel has been evaluated in terms of its thermal efficiency via warm water collection and PV efficiency via the output electricity. The laboratory test results demonstrate that significant energy conversion efficiency improvement can be achieved for both electricity generation and heat collection by the presented BIPVT roofing system. Overall, the performance indicates a very promising prospective of the new BIPVT multifunctional roofing panel.

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part one: introduction, and mind-body exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Imoto, Aline Mizusaki; Toupin-April, Karine; Westby, Marie; Gallardo, Inmaculada C Álvarez; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; Angelis, Gino De; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective mind-body exercise programs and provide clinicians and patients with updated, high-quality recommendations concerning non-traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with mind-body exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+, D-) was used, based on statistical significance ( P osteoarthritis. Hatha Yoga demonstrated significant improvement for pain relief (Grade B) and physical function (Grade C+). Tai Chi Qigong demonstrated significant improvement for quality of life (Grade B), pain relief (Grade C+) and physical function (Grade C+). Sun style Tai Chi gave significant improvement for pain relief (Grade B) and physical function (Grade B). Mind-body exercises are promising approaches to reduce pain, as well as to improve physical function and quality of life for individuals with knee osteoarthritis.

Preparation and Fatigue Properties of Functionally Graded Cemented Carbides

International Nuclear Information System (INIS)

Liu Yong; Liu Fengxiao; Liaw, Peter K.; He Yuehui

2008-01-01

Cemented carbides with a functionally graded structure have significantly improved mechanical properties and lifetimes in cutting, drilling and molding. In this work, WC-6 wt.% Co cemented carbides with three-layer graded structure (surface layer rich in WC, mid layer rich in Co and the inner part of the average composition) were prepared by carburizing pre-sintered η-phase-containing cemented carbides. The three-point bending fatigue tests based on the total-life approach were conducted on both WC-6wt%Co functionally graded cemented carbides (FGCC) and conventional WC-6wt%Co cemented carbides. The functionally graded cemented carbide shows a slightly higher fatigue limit (∼100 MPa) than the conventional ones under the present testing conditions. However, the fatigue crack nucleation behavior of FGCC is different from that of the conventional ones. The crack nucleates preferentially along the Co-gradient and perpendicular to the tension surface in FGCC, while parallel to the tension surface in conventional cemented carbides

Ottawa Panel evidence-based clinical practice guidelines for the management of osteoarthritis in adults who are obese or overweight.

Science.gov (United States)

Brosseau, Lucie; Wells, George A; Tugwell, Peter; Egan, Mary; Dubouloz, Claire-Jehanne; Casimiro, Lynn; Bugnariu, Nicoleta; Welch, Vivian A; De Angelis, Gino; Francoeur, Lilliane; Milne, Sarah; Loew, Laurianne; McEwan, Jessica; Messier, Steven P; Doucet, Eric; Kenny, Glen P; Prud'homme, Denis; Lineker, Sydney; Bell, Mary; Poitras, Stéphane; Li, Jing Xian; Finestone, Hillel M; Laferrière, Lucie; Haines-Wangda, Angela; Russell-Doreleyers, Marion; Lambert, Kim; Marshall, Alison D; Cartizzone, Margot; Teav, Adam

2011-06-01

The objective of this review was to construct an updated evidence-based clinical practice guideline on the use of physical activity and diet for the management of osteoarthritis (OA) in adults (>18 years of age) who are obese or overweight (body mass index ≥25 kg/m(2)). Articles were extracted from the following databases: MEDLINE, EMBASE (Current Contents), SPORTDiscus, SUM, Scopus, CINAHL, AMED, BIOMED, PubMed, ERIC, the Cochrane Controlled Trials, and PEDro. The Ottawa Panel and research assistance team strictly applied the inclusion and exclusion criteria from previous Ottawa Panel publications. An a priori literature search was conducted for articles related to obesity and OA of the lower extremities that were published from January 1, 1966, to November 30, 2010. Inclusion criteria and the methods to grade the recommendations were created by the Ottawa Panel. were graded based on the strength of evidence (A, B, C, C+, D, D+, or D-) as well as experimental design (I for randomized controlled trials and II for nonrandomized studies). In agreement with previous Ottawa Panel methods, Cochrane Collaboration methods were utilized for statistical analysis. Clinical significance was established by an improvement of ≥15% in the experimental group compared with the control group. There were a total of 79 recommendations from 9 articles. From these recommendations, there were 36 positive recommendations: 21 grade A and 15 grade C+. There were no grade B recommendations, and all recommendations were of clinical benefit. Further research is needed, as more than half of the trials were of low methodological quality. This review suggests that physical activity and diet programs are beneficial, specifically for pain relief (9 grade A recommendations) and improved functional status (6 grade A and 7 grade C+ recommendations), for adults with OA who are obese or overweight. The Ottawa Panel was able to demonstrate that when comparing physical activity alone, diet alone

The Ottawa panel clinical practice guidelines for the management of knee osteoarthritis. Part two: strengthening exercise programs.

Science.gov (United States)

Brosseau, Lucie; Taki, Jade; Desjardins, Brigit; Thevenot, Odette; Fransen, Marlene; Wells, George A; Mizusaki Imoto, Aline; Toupin-April, Karine; Westby, Marie; Álvarez Gallardo, Inmaculada C; Gifford, Wendy; Laferrière, Lucie; Rahman, Prinon; Loew, Laurianne; De Angelis, Gino; Cavallo, Sabrina; Shallwani, Shirin Mehdi; Aburub, Ala'; Bennell, Kim L; Van der Esch, Martin; Simic, Milena; McConnell, Sara; Harmer, Alison; Kenny, Glen P; Paterson, Gail; Regnaux, Jean-Philippe; Lefevre-Colau, Marie-Martine; McLean, Linda

2017-05-01

To identify effective strengthening exercise programs and provide rehabilitation teams and patients with updated, high-quality recommendations concerning traditional land-based exercises for knee osteoarthritis. A systematic search and adapted selection criteria included comparative controlled trials with strengthening exercise programs for patients with knee osteoarthritis. A panel of experts reached consensus on the recommendations using a Delphi survey. A hierarchical alphabetical grading system (A, B, C+, C, D, D+ or D-) was based on statistical significance ( p osteoarthritis management within a six-month period. Strengthening exercise programs demonstrated a significant improvement for pain relief (four Grade A, ten Grade B, two Grade C+), physical function (four Grade A, eight Grade B) and quality of life (three Grade B). Strengthening in combination with other types of exercises (coordination, balance, functional) showed a significant improvement in pain relief (three Grade A, 11 Grade B, eight Grade C+), physical function (two Grade A, four Grade B, three Grade C+) and quality of life (one Grade A, one Grade C+). There are a variety of choices for strengthening exercise programs with positive recommendations for healthcare professionals and knee osteoarthritis patients. There is a need to develop combined behavioral and muscle-strengthening strategies to improve long-term maintenance of regular strengthening exercise programs.

Vibration of Elastic Functionally Graded Thick Rings

Directory of Open Access Journals (Sweden)

Guang-Hui Xu

2017-01-01

Full Text Available The free vibration behaviors of functionally graded rings were investigated theoretically. The material graded in the thickness direction according to the power law rule and the rings were assumed to be in plane stress and plane strain states. Based on the first-order shear deformation theory and the kinetic relation of von Kárman type, the frequency equation for free vibration of functionally graded ring was derived. The derived results were verified by those in literatures which reveals that the present theory can be appropriate to predict the free vibration characteristics for quite thick rings with the radius-to-thickness ratio from 60 down to 2.09. Comparison between the plane stress case and the plane strain case indicates a slight difference. Meanwhile, the effects of the structural dimensional parameters and the material inhomogeneous parameter are examined. It is interesting that the value of the logarithmic form of vibration frequency is inversely proportional to the logarithmic form of the radius-to-thickness ratio or the mean radius.

Aeroelastic Tailoring of a Plate Wing with Functionally Graded Materials

Science.gov (United States)

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

2014-01-01

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

Investigation of dynamic fracture behavior in functionally graded materials

International Nuclear Information System (INIS)

Yang, X B; Qin, Y P; Zhuang, Z; You, X C

2008-01-01

The fast running crack in functionally graded materials (FGMs) is investigated through numerical simulations under impact loading. Some fracture characterizations such as crack propagation and arrest are evaluated by the criterion of the crack tip opening angle. Based on the experimental results, the whole propagation process of the fast running crack is simulated by the finite element program. Thus, the dynamic fracture parameters can be obtained during the crack growing process. In this paper, the crack direction is assumed to be the graded direction of the materials, and the property gradation in FGMs is considered by varying the elastic modulus exponentially along the graded direction and keeping the mass density and Poisson's ratio constant. The influences of the non-homogeneity, the loading ratio and the crack propagation speed on the dynamic fracture response of FGMs are analyzed through the test and numerical analysis. Considering the potential application of FGMs in natural-gas transmission engineering, a functionally graded pipeline is designed to arrest the fast running crack for a short period in high pressure large diameter natural-gas pipelines

Dynamic relaxation method for nonlinear buckling analysis of moderately thick FG cylindrical panels with various boundary conditions

Energy Technology Data Exchange (ETDEWEB)

Golmakani, M. E.; Far, M. N. Sadraee; Moravej, M. [Dept. of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of)

2016-12-15

Using new approach proposed by Dynamic relaxation (DR) method, buckling analysis of moderately thick Functionally graded (FG) cylindrical panels subjected to axial compression is investigated for various boundary conditions. The mechanical properties of FG panel are assumed to vary continuously along the thickness direction by the simple rule of mixture and Mori-Tanaka model. The incremental form of nonlinear formulations are derived based on First-order shear deformation theory (FSDT) and large deflection von Karman equations. The DR method combined with the finite difference discretization technique is employed to solve the incremental form of equilibrium equations. The critical mechanical buckling load is determined based on compressive load-displacement curve by adding the incremental displacements in each load step to the displacements obtained from the previous ones. A detailed parametric study is carried out to investigate the influences of the boundary conditions, rule of mixture, grading index, radius-to-thickness ratio, length-to-radius ratio and panel angle on the mechanical buckling load. The results reveal that with increase of grading index the effect of radius-to-thickness ratio on the buckling load decreases. It is also observed that effect of distribution rules on the buckling load is dependent to the type of boundary conditions.

Analysis, manufacture and characterization of Ni/Cu functionally graded structures

International Nuclear Information System (INIS)

Rubio, Wilfredo Montealegre; Paulino, Glaucio H.; Silva, Emilio Carlos Nelli

2012-01-01

Highlights: ► Functionally graded structures (FGSs) of nickel and copper can be manufactured. ► The hardness curve of FGS can be used for approximating the gradation function of elastic properties. ► The graded finite element approaches with great accuracy the FGS resonance frequencies obtained experimentally. -- Abstract: In this work, an experimental and numerical analysis and characterization of functionally graded structures (FGSs) is developed. Nickel (Ni) and copper (Cu) materials are used as basic materials in the numerical modeling and experimental characterization. For modeling, a MATLAB finite element code is developed, which allows simulation of harmonic and modal analysis considering the graded finite element formulation. For experimental characterization, Ni–Cu FGSs are manufactured by using spark plasma sintering technique. Hardness and Young’s modulus are found by using microindentation and ultrasonic measurements, respectively. The effective gradation of Ni/Cu FGS is addressed by means of optical microscopy, energy dispersive spectrometry, scanning electron microscopy and hardness testing. For the purpose of comparing modeling and experimental results, the hardness curve, along the gradation direction, is used for identifying the gradation profile; accordingly, the experimental hardness curve is used for approximating the Young’s modulus variation and the graded finite element modeling is used for verification. For the first two resonance frequency values, a difference smaller than 1% between simulated and experimental results is obtained.

Application of ANFIS for analytical modeling of tensile strength of functionally graded steels

Directory of Open Access Journals (Sweden)

Ali Nazari

2012-06-01

Full Text Available In the present study, the tensile strength of ferritic and austenitic functionally graded steels produced by electroslag remelting has been modeled. To produce functionally graded steels, two slices of plain carbon steel and austenitic stainless steels were spot welded and used as electroslag remelting electrode. Functionally graded steel containing graded layers of ferrite and austenite may be fabricated via diffusion of alloying elements during remelting stage. Vickers microhardness profile of the specimen has been obtained experimentally and modeled with adaptive network-based fuzzy inference systems (ANFIS. To build the model for graded ferritic and austenitic steels, training, testing and validation using respectively 174 and 120 experimental data were conducted. According to the input parameters, in the ANFIS model, the Vickers microhardness of each layer was predicted. A good fit equation which correlates the Vickers microhardness of each layer to its corresponding chemical composition was achieved by the optimized network for both ferritic and austenitic graded steels. Afterwards; the Vickers microhardness of each layer in functionally graded steels was related to the yield stress of the corresponding layer and by assuming Holloman relation for stress-strain curve of each layer, they were acquired. Finally, by applying the rule of mixtures, tensile strength of functionally graded steels configuration was found through a numerical method. The obtained results from the proposed model are in good agreement with those acquired from the experiments.

Compositional control of continuously graded anode functional layer

Science.gov (United States)

McCoppin, J.; Barney, I.; Mukhopadhyay, S.; Miller, R.; Reitz, T.; Young, D.

2012-10-01

In this work, solid oxide fuel cells (SOFC's) are fabricated with linear-compositionally graded anode functional layers (CGAFL) using a computer-controlled compound aerosol deposition (CCAD) system. Cells with different CGAFL thicknesses (30 um and 50 um) are prepared with a continuous compositionally graded interface deposited between the electrolyte and anode support current collecting regions. The compositional profile was characterized using energy dispersive X-ray spectroscopic mapping. An analytical model of the compound aerosol deposition was developed. The model predicted compositional profiles for both samples that closely matched the measured profiles, suggesting that aerosol-based deposition methods are capable of creating functional gradation on length scales suitable for solid oxide fuel cell structures. The electrochemical performances of the two cells are analyzed using electrochemical impedance spectroscopy (EIS).

Bio-inspired composites with functionally graded platelets exhibit enhanced stiffness.

Science.gov (United States)

Tapse, Sanjay; S, Anup

2017-11-09

Unidirectional composites inspired from biological materials such as nacre, are composed of stiff platelets arranged in a staggered manner within a soft matrix. Elaborate analyses have been conducted on the aforementioned composites and they are found to have excellent mechanical properties like stiffness, strength and fracture toughness. The superior properties exhibited by these composites have been proved to be the result of its unique structure. An emerging development in the field of composite structures is Functionally Graded Composites(FGC), whose properties vary spatially and possess enhanced thermo-mechanical properties. In this paper, the platelets are functionally graded with its Young's Modulus varying parabolically along the length. Two different models - namely, Tension Shear Chain Model and Minimisation of Complementary Energy Model have been employed to obtain the stiffness of the overall composite analytically. The effect of various parameters that define the composite model such as overlapping length between any two neighbouring platelets, different gradation parameters and platelet aspect ratio on the overall mechanical properties have been studied. Composites with functionally graded platelets are found to possess enhanced stiffness (upto 14% higher) for certain values of these parameters. The obtained solutions have been validated using Finite Element Analysis. Bio-inspired composites with functionally graded platelets can be engineered for structural applications, such as in automobile, aerospace and aircraft industry, where stiffness plays a crucial role. © 2017 IOP Publishing Ltd.

Analysis Of Dynamic Dent Resistance Of Auto Body Panel

International Nuclear Information System (INIS)

Deolgaonkar, S. S.; Nandedkar, V. M.

2007-01-01

In automotive industry there is increasing demand for higher quality exterior panels, better functional properties and lower weight. The demand for weight reduction has led to thinner sheets, greater use of high strength steels and a change from steel to aluminum grades. This thickness reduction, which causes decrease in the dent resistance, promoted examination of the dent resistance against static and dynamic concentrated loads. This paper describes an investigation of the suitability of explicit dynamic FE analysis as a mean to determine the dynamic dent properties of the panel. This investigation is carried out on the body panel of utility vehicle and covers two parts, in first experimental analysis is carried out on developed test rig, which is interfaced with the computer. This test rig measures deflection with accuracy of .001mm. The experimental results are then compared with the simulation results, which is the second part. Simulation is carried with non-linear transient dynamic explicit analysis using Ansys -Ls Dyna. The experimental results show great accuracy with simulation results. The effect of change in thickness and geometry of the existing fender is then studied with help of simulation technique. By considering the best possible option overall weight of fender is reduced by 7.07 % by keeping the dent resistance of the panel constant

Fracture Analysis of Functionally Graded Materials

International Nuclear Information System (INIS)

Zhang, Ch.; Gao, X. W.; Sladek, J.; Sladek, V.

2010-01-01

This paper reports our recent research works on crack analysis in continuously non-homogeneous and linear elastic functionally graded materials. A meshless boundary element method is developed for this purpose. Numerical examples are presented and discussed to demonstrate the efficiency and the accuracy of the present numerical method, and to show the effects of the material gradation on the crack-opening-displacements and the stress intensity factors.

The Contribution of Executive Functions to Narrative Writing in Fourth Grade Children

Science.gov (United States)

Drijbooms, Elise; Groen, Margriet A.; Verhoeven, Ludo

2015-01-01

The present study investigated the contribution of executive functions to narrative writing in fourth grade children, and evaluated to what extent executive functions contribute differentially to different levels of narrative composition. The written skills of 102 Dutch children in fourth grade were assessed using a narrative picture-elicitation…

Optimum material gradient composition for the functionally graded ...

African Journals Online (AJOL)

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To this end, various static tests for functionally graded ... different poling directions, high stress concentrations are usually appeared at the layer interfaces under ...... Use of classical plate finite elements for the analysis of electroactive ...

The effect of multi-directional nanocomposite materials on the vibrational response of thick shell panels with finite length and rested on two-parameter elastic foundations

Science.gov (United States)

Tahouneh, Vahid; Naei, Mohammad Hasan

2016-03-01

The main purpose of this paper is to investigate the effect of bidirectional continuously graded nanocomposite materials on free vibration of thick shell panels rested on elastic foundations. The elastic foundation is considered as a Pasternak model after adding a shear layer to the Winkler model. The panels reinforced by randomly oriented straight single-walled carbon nanotubes are considered. The volume fractions of SWCNTs are assumed to be graded not only in the radial direction, but also in axial direction of the curved panel. This study presents a 2-D six-parameter power-law distribution for CNTs volume fraction of 2-D continuously graded nanocomposite that gives designers a powerful tool for flexible designing of structures under multi-functional requirements. The benefit of using generalized power-law distribution is to illustrate and present useful results arising from symmetric, asymmetric and classic profiles. The material properties are determined in terms of local volume fractions and material properties by Mori-Tanaka scheme. The 2-D differential quadrature method as an efficient numerical tool is used to discretize governing equations and to implement boundary conditions. The fast rate of convergence of the method is shown and results are compared against existing results in literature. Some new results for natural frequencies of the shell are prepared, which include the effects of elastic coefficients of foundation, boundary conditions, material and geometrical parameters. The interesting results indicate that a graded nanocomposite volume fraction in two directions has a higher capability to reduce the natural frequency than conventional 1-D functionally graded nanocomposite materials.

Modelling of electric characteristics of 150-watt peak solar panel using Boltzmann sigmoid function under various temperature and irradiance

Science.gov (United States)

Sapteka, A. A. N. G.; Narottama, A. A. N. M.; Winarta, A.; Amerta Yasa, K.; Priambodo, P. S.; Putra, N.

2018-01-01

Solar energy utilized with solar panel is a renewable energy that needs to be studied further. The site nearest to the equator, it is not surprising, receives the highest solar energy. In this paper, a modelling of electrical characteristics of 150-Watt peak solar panels using Boltzmann sigmoid function under various temperature and irradiance is reported. Current, voltage, temperature and irradiance data in Denpasar, a city located at just south of equator, was collected. Solar power meter is used to measure irradiance level, meanwhile digital thermometer is used to measure temperature of front and back panels. Short circuit current and open circuit voltage data was also collected at different temperature and irradiance level. Statistically, the electrical characteristics of 150-Watt peak solar panel can be modelled using Boltzmann sigmoid function with good fit. Therefore, it can be concluded that Boltzmann sigmoid function might be used to determine current and voltage characteristics of 150-Watt peak solar panel under various temperature and irradiance.

Compressive properties of sandwiches with functionally graded

Indian Academy of Sciences (India)

The compressive behaviour of a new class of sandwich composite made up of jute fiber reinforced epoxy skins and piece-wise linear fly ash reinforced functionally graded (FG) rubber core is investigated in flat-wise mode. FG samples are prepared using conventional casting technique. Presence of gradation is quantified ...

Functionally graded Nylon-11/silica nanocomposites produced by selective laser sintering

International Nuclear Information System (INIS)

Chung, Haseung; Das, Suman

2008-01-01

Selective laser sintering (SLS), a layered manufacturing-based freeform fabrication approach was explored for constructing three-dimensional structures in functionally graded polymer nanocomposites. Here, we report on the processing and properties of functionally graded polymer nanocomposites of Nylon-11 filled with 0-10% by volume of 15 nm fumed silica nanoparticles. SLS processing parameters for the different compositions were developed by design of experiments (DOE). The densities and micro/nanostructures of the nanocomposites were examined by optical microscopy and transmission electron microscopy (TEM). The tensile and compressive properties for each composition were then tested. These properties exhibit a nonlinear variation as a function of filler volume fraction. Finally, two component designs exhibiting a one-dimensional polymer nanocomposite material gradient were fabricated. The results indicate that particulate-filled functionally graded polymer nanocomposites exhibiting a one-dimensional composition gradient can be successfully processed by SLS to produce three-dimensional components with spatially varying mechanical properties

Numerical simulation of thermal fracture in functionally graded

Indian Academy of Sciences (India)

Numerical simulation of thermal fracture in functionally graded materials using element-free ... Initially, the temperature distribution over the domain is obtained by solving the heat transfer problem. ... Department of Mechanical Engineering, National Institute of Technology, Hamirpur 177005, India ... Contact | Site index.

ALBI versus Child-Pugh grading systems for liver function in patients with hepatocellular carcinoma.

Science.gov (United States)

Na, Seong K; Yim, Sun Y; Suh, Sang J; Jung, Young K; Kim, Ji H; Seo, Yeon S; Yim, Hyung J; Yeon, Jong E; Byun, Kwan S; Um, Soon H

2018-04-01

The prognostic performance of the albumin-bilirubin (ALBI) grade in hepatocellular carcinoma (HCC) as an objective method of assessing liver function was investigated. Data from 2099 patients with HCC in Korea were collected and analyzed retrospectively. The discriminative performance of ALBI grade was compared with Child-Pugh (C-P) grade for different stages or treatments. The median follow up duration was 16.2 months (range: 1.0-124.9). The median survival times were 49.7 months for C-P grade A (65.8%), 12.4 months for C-P grade B (25.5%), and 4.2 months for C-P grade C (8.6%) (P < 0.001). The median survival times were 84.2 months for ALBI grade 1 (32.8%), 25.5 months for ALBI grade 2 (53.5%), and 7.7 months for ALBI grade 3 (13.7%) (P < 0.001). In early UICC stages, ALBI grade showed better discriminative performance than C-P grade. In curative treatments, ALBI grade also showed better discriminative performance than C-P grade (Harrell's C: 0.624 (C-P grade) vs 0.667 [ALBI grade]). ALBI grade provided better prognostic performance in survival analysis and better distribution of the grades than C-P grade in HCC, suggesting that ALBI grade could be a good alternative grading system for liver function in patients with HCC. © 2018 Wiley Periodicals, Inc.

Make Your Own Solar Panel.

Science.gov (United States)

Suzuki, David

1992-01-01

Presents an activity in which students make a simulated solar panel to learn about the principles behind energy production using solar panels. Provides information about how solar panels function to produce energy. (MCO)

Vibration analysis of a functionally graded piezoelectric cylindrical actuator

International Nuclear Information System (INIS)

Zhang, T T; Shi, Z F; Spencer, B F Jr

2008-01-01

This paper focuses on the response of a functionally graded piezoelectric cylindrical actuator placed in a harmonic electric field based on elastic membrane theory and shell theory. The actuator is polarized in the radial direction with its piezoelectric coefficient d 31 varying linearly along the axial direction. In the present investigation, non-dimensional expressions are introduced, and analytical solutions for this class of actuator are obtained. The results provided in the present study are compared with other investigations, with good agreement being found. The major differences between a functionally graded actuator and an actuator with homogeneous material properties are identified, and the advantages of the former are demonstrated. In the last section of this paper, limitations of membrane theory and shell theory models are discussed

Functionally graded biomimetic energy absorption concept development for transportation systems.

Science.gov (United States)

2014-02-01

Mechanics of a functionally graded cylinder subject to static or dynamic axial loading is considered, including a potential application as energy absorber. The mass density and stiffness are power functions of the radial coordinate as may be the case...

Geometrically non linear analysis of functionally graded material ...

African Journals Online (AJOL)

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when compared to the other engineering materials (Akhavan and Hamed, 2010). However, FGM plates under mechanical loading may undergo elastic instability. Hence, the non-linear behavior of functionally graded plates has to be understood for their optimum design. Reddy (2000) proposed the theoretical formulation ...

Functionally Graded Materials Database

Science.gov (United States)

Kisara, Katsuto; Konno, Tomomi; Niino, Masayuki

2008-02-01

Functionally Graded Materials Database (hereinafter referred to as FGMs Database) was open to the society via Internet in October 2002, and since then it has been managed by the Japan Aerospace Exploration Agency (JAXA). As of October 2006, the database includes 1,703 research information entries with 2,429 researchers data, 509 institution data and so on. Reading materials such as "Applicability of FGMs Technology to Space Plane" and "FGMs Application to Space Solar Power System (SSPS)" were prepared in FY 2004 and 2005, respectively. The English version of "FGMs Application to Space Solar Power System (SSPS)" is now under preparation. This present paper explains the FGMs Database, describing the research information data, the sitemap and how to use it. From the access analysis, user access results and users' interests are discussed.

High maneuverability guidewire with functionally graded properties using new superelastic alloys.

Science.gov (United States)

Sutou, Y; Yamauchi, K; Suzuki, M; Furukawa, A; Omori, T; Takagi, T; Kainuma, R; Nishida, M; Ishida, K

2006-01-01

Nitinol shape memory alloys (SMAs) are attracting considerable attention as core materials for medical guidewires because of their excellent flexibility and shape retention. However, since Nitinol guidewires possess low rigidity, the pushability and torquability of the guidewires are insufficient. On the other hand, although guidewires made of stainless steel have high pushability, plastic deformation occurs easily. We have developed a new class of superelastic guidewires with functionally graded properties from the tip to the end by using new SMA core materials such as Cu-Al-Mn-based or Ni-free Ti-Mo-Sn SMAs. The tip portion of the guidewire shows excellent superelasticity (SE), while the body portion possesses high rigidity. These functionally graded characteristics can be realized by microstructural control. These guidewires with functionally graded properties show excellent pushability and torquability and are considerably easier to handle than conventional guidewires with Nitinol or stainless steel cores. Moreover, a metallic catheter using a Ni-free Ti-based SMA with high biocompatibility is introduced.

Interfacial adhesion of laser clad functionally graded materials

NARCIS (Netherlands)

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

2003-01-01

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

Interfacial adhesion of laser clad functionally graded materials

NARCIS (Netherlands)

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

2002-01-01

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

Optimum material gradient composition for the functionally graded ...

African Journals Online (AJOL)

This study investigates the relation between the material gradient properties and the optimum sensing/actuation design of the functionally graded piezoelectric beams. Three-dimensional (3D) finite element analysis has been employed for the prediction of an optimum composition profile in these types of sensors and ...

Functionally graded Ti6Al4V and Inconel 625 by Laser Metal Deposition

Science.gov (United States)

Pulugurtha, Syamala R.

The objective of the current work was to fabricate a crack-free functionally graded Ti6Al4V and Inconel 625 thin wall structure by Laser Metal Deposition (LMD). One potential application for the current material system is the ability to fabricate a functionally graded alloy that can be used in a space heat exchanger. The two alloys, Inconel 625 and Ti6Al4V are currently used for aerospace applications. They were chosen as candidates for grading because functionally grading those combines the properties of high strength/weight ratio of Ti6Al4V and high temperature oxidation resistance of Inconel 625 into one multifunctional material for the end application. However, there were challenges associated with the presence of Ni-Ti intermetallic phases (IMPs). The study focused on several critical areas such as (1) understanding microstructural evolution, (2) reducing macroscopic cracking, and (3) reducing mixing between graded layers. Finite element analysis (FEA) was performed to understand the effect of process conditions on multilayer claddings for simplified material systems such as SS316L and Inconel 625 where complex microstructures did not form. The thermo-mechanical models were developed using Abaqus(TM) (and some of them experimentally verified) to predict temperature-gradients; remelt layer depths and residual stresses. Microstructure evolution along the functionally graded Ti6Al4V and Inconel 625 was studied under different processing and grading conditions. Thermodynamic modeling using Factsage (v 6.1) was used to construct phase diagrams and predict the possible equilibrium major/minor phases (verified experimentally by XRD) that may be present along the functionally graded Ti6Al4V and Inconel 625 thin wall structures.

Thin Film Photovoltaic/Thermal Solar Panels

Institute of Scientific and Technical Information of China (English)

David JOHNSTON

2008-01-01

A solar panel is described.in which thin films of semiconductor are deposited onto a metal substrate.The semiconductor-metal combination forms a thin film photovoltaic cell,and also acts as a reflector,absorber tandem, which acts as a solar selective surface,thus enhancing the solar thermal performance of the collector plate.The use of thin films reduces the distance heat is required to flow from the absorbing surface to the metal plate and heat exchange conduits.Computer modelling demonstrated that,by suitable choice of materials,photovohaic efficiency call be maintained,with thermal performance slishtly reduced,compared to that for thermal-only panels.By grading the absorber layer-to reduce the band gap in the lower region-the thermal performance can be improved,approaching that for a thermal-only solar panel.

Design, Manufacturing and Characterization of Functionally Graded Flextensional Piezoelectric Actuators

International Nuclear Information System (INIS)

Amigo, R C R; Vatanabe, S L; Silva, E C N

2013-01-01

Previous works have been shown several advantages in using Functionally Graded Materials (FGMs) for the performance of flextensional devices, such as reduction of stress concentrations and gains in reliability. In this work, the FGM concept is explored in the design of graded devices by using the Topology Optimization Method (TOM), in order to determine optimal topologies and gradations of the coupled structures of piezoactuators. The graded pieces are manufactured by using the Spark Plasma Sintering (SPS) technique and are bonded to piezoelectric ceramics. The graded actuators are then tested by using a modular vibrometer system for measuring output displacements, in order to validate the numerical simulations. The technological path developed here represents the initial step toward the manufacturing of an integral piezoelectric device, constituted by piezoelectric and non-piezoelectric materials without bonding layers.

Fabrication and characteristics of alumina-iron functionally graded materials

DEFF Research Database (Denmark)

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

2009-01-01

. The microstructure and the composition of the prepared component were studied, and its flexural strength, fracture toughness, and fracture energy were tested and evaluated. The relative density and the Vickers hardness of each layer in the graded material were also measured. The correlation between microstructure...... and composition and mechanical properties was discussed. Flat, crack-free, and relatively high-density gradient components were obtained from this work. Compared to monolithic alumina ceramic, the remarkable improvement on fracture toughness and fracture energy of the investigated graded material system......In the present work, five-layered alumina–iron functionally graded materials (FGMs) were fabricated via a simple route of die pressing and pressureless sintering. The shrinkage differences among the layers in the FGM were minimized by particle size selection and processing control...

Buckling Response of Thick Functionally Graded Plates

Directory of Open Access Journals (Sweden)

BOUAZZA MOKHTAR

2014-11-01

Full Text Available In this paper, the buckling of a functionally graded plate is studied by using first order shear deformation theory (FSDT. The material properties of the plate are assumed to be graded continuously in the direction of thickness. The variation of the material properties follows a simple power-law distribution in terms of the volume fractions of constituents. The von Karman strains are used to construct the equilibrium equations of the plates subjected to two types of thermal loading, linear temperature rise and gradient through the thickness are considered. The governing equations are reduced to linear differential equation with boundary conditions yielding a simple solution procedure. In addition, the effects of temperature field, volume fraction distributions, and system geometric parameters are investigated. The results are compared with the results of the no shear deformation theory (classic plate theory, CPT.

Solar Panels and Alternative Energy in the Eighth-Grade Classroom

Science.gov (United States)

Buck, Laura

2010-01-01

In this solar panels and alternative energy project, students were challenged to develop a researchable question about solar energy and electronics and devise a means of answering it. Students worked cooperatively, with specific roles for each member, conducting research, conducting experiments, analyzing results, and writing the final…

Functionally graded materials for impedance matching in elastic media

International Nuclear Information System (INIS)

Chen, Shi; Zhang, Yinhong; Hao, Changchun; Lin, Shuyu; Fu, Zhiqiang

2014-01-01

When functionally graded material layers are inserted between two impedance mismatching media, passbands with extremely large bandwidths can appear in these layered systems. An accurate and effective iterative method is developed to deal with these layered systems with extremely large layer number.

Functionally graded materials for impedance matching in elastic media

Energy Technology Data Exchange (ETDEWEB)

Chen, Shi; Zhang, Yinhong, E-mail: zyh5337@163.com; Hao, Changchun; Lin, Shuyu; Fu, Zhiqiang

2014-01-03

When functionally graded material layers are inserted between two impedance mismatching media, passbands with extremely large bandwidths can appear in these layered systems. An accurate and effective iterative method is developed to deal with these layered systems with extremely large layer number.

Functionally graded materials produced with high power lasers

NARCIS (Netherlands)

De Hosson, J. T. M.; Ocelik, V.; Chandra, T; Torralba, JM; Sakai, T

2003-01-01

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

Are the uterine serous carcinomas underdiagnosed? Histomorphologic and immunohistochemical correlates and clinical follow up in high-grade endometrial carcinomas initially diagnosed as high-grade endometrioid carcinoma.

Science.gov (United States)

Hu, Shaomin; Hinson, Jeff L; Matnani, Rahul; Cibull, Michael L; Karabakhtsian, Rouzan G

2018-02-01

Histologic subclassification of high-grade endometrial carcinomas can sometimes be a diagnostic challenge when based on histomorphology alone. Here we utilized immunohistochemical markers to determine the immunophenotype in histologically ambiguous high-grade endometrial carcinomas that were initially diagnosed as pure or mixed high-grade endometrioid carcinoma, aiming to determine the utility of selected immunohistochemical panel in accurate classification of these distinct tumor types, while correlating these findings with the clinical outcome. A total of 43 high-grade endometrial carcinoma cases initially classified as pure high-grade endometrioid carcinoma (n=32), mixed high-grade endometrioid carcinoma/serous carcinoma (n=9) and mixed high-grade endometrioid carcinoma/clear cell carcinoma (n=2) were retrospectively stained with a panel of immunostains, including antibodies for p53, p16, estrogen receptor, and mammaglobin. Clinical follow-up data were obtained, and stage-to-stage disease outcomes were compared for different tumor types. Based on aberrant staining for p53 and p16, 17/43 (40%) of the high-grade endometrial carcinoma cases initially diagnosed as high-grade endometrioid carcinoma were re-classified as serous carcinoma. All 17 cases showed negative staining for mammaglobin, while estrogen receptor was positive in only 6 (35%) cases. The remaining 26 cases of high-grade endometrioid carcinoma showed wild-type staining for p53 in 25 (96%) cases, patchy staining for p16 in 20 (77%) cases, and were positive for mammaglobin and estrogen receptor in 8 (31%) and 19 (73%) cases, respectively, thus the initial diagnosis of high-grade endometrioid carcinoma was confirmed in these cases. In addition, the patients with re-classified serous carcinoma had advanced clinical stages at diagnosis and poorer overall survival on clinical follow-up compared to that of the remaining 26 high-grade endometrioid carcinoma cases. These results indicate that selected

Free vibration analysis of multi directional functionally graded circular and annular plates

Energy Technology Data Exchange (ETDEWEB)

Kermani, Iman Davoodi; Ghayour, Mostafa; Mirdamadi, Hamid Reza [Isfahan Univ. of Technology, Isfahan (Iran, Islamic Republic of)

2012-11-15

This paper addresses the free vibration of multi directional functionally graded circular and annular plates using a semianalytical/numerical method, called state space based differential quadrature method. Three-dimensional elasticity equations are derived for multi directional functionally graded plates and a solution is given by the semi-analytical/numerical method. This method gives an analytical solution along the thickness direction, using a state space method and a numerical solution using differential quadrature method. Some numerical examples are presented to show the accuracy and convergence of the method. The most of simulations of the present study have been validated by the existing literature. The non dimensional frequencies and corresponding displacements mode shapes are obtained. Then the influences of thickness ratio and graded indexes are demonstrated on the non dimensional natural frequencies.

Neonates with reduced neonatal lung function have systemic low-grade inflammation

DEFF Research Database (Denmark)

Chawes, Bo L.K.; Stokholm, Jakob; Bønnelykke, Klaus

2015-01-01

Background: Children and adults with asthma and impaired lung function have been reported to have low-grade systemic inflammation, but it is unknown whether this inflammation starts before symptoms and in particular whether low-grade inflammation is present in asymptomatic neonates with reduced...... lung function. ObjectiveWe sought to investigate the possible association between neonatal lung function and biomarkers of systemic inflammation.  Methods: Plasma levels of high-sensitivity C-reactive protein (hs-CRP), IL-1β, IL-6, TNF-α, and CXCL8 (IL-8) were measured at age 6 months in 300 children.......  Results: The neonatal forced expiratory volume at 0.5 seconds was inversely associated with hs-CRP (β-coefficient, −0.12; 95% CI, −0.21 to −0.04; P approach, including hs-CRP, IL-6...

When Patients Write the Guidelines: Patient Panel Recommendations for the Treatment of Rheumatoid Arthritis.

Science.gov (United States)

Fraenkel, Liana; Miller, Amy S; Clayton, Kelly; Crow-Hercher, Rachelle; Hazel, Shantana; Johnson, Britt; Rott, Leslie; White, Whitney; Wiedmeyer, Carole; Montori, Victor M; Singh, Jasvinder A; Nowell, W Benjamin

2016-01-01

How best to involve patients in the development of clinical practice guideline (CPG) recommendations is not known. We sought to determine the feasibility and value of developing CPG recommendations based on a voting panel composed entirely of patients, with the ultimate goal of comparing the patients' recommendations to ones developed by a physician-dominated voting panel on the same clinical questions. Ten patients with rheumatoid arthritis completed 8 hours of training on evidence-based medicine and guideline development. They constituted a voting panel and, with 2 American College of Rheumatology staff with expertise in CPG development and a physician facilitator, subsequently met at a face-to-face meeting to develop recommendations. They applied the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology to formulate recommendations on 18 questions for which there was evidence warranting moderate or high confidence. The patient panel developed recommendations for 16 of the 18 questions; for the other 2, the panel thought there were insufficient data to support a recommendation. For 13 of the 16 questions, the patient panel recommended the same course of action as did the physician-dominated panel. Differences were due to how the 2 panels valued the balance between benefits and harms. Patient and physician-dominated panels developed the same recommendations for most questions for which there was evidence warranting moderate to high confidence. Additional experiences are necessary to advance the evidence necessary to determine what panel composition is optimal to produce the best guidelines. © 2015, American College of Rheumatology.

Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

Science.gov (United States)

Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

2015-08-01

Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functionally graded bioactive coatings: From fabrication to testing

Science.gov (United States)

Foppiano, Silvia

Every year about half a million Americans undergo total joint replacement surgery of some kind. This number is expected to steadily increase in the future. About 20% of these patients will need a revision surgery because of implant failure, with a significant increase in health care cost. Current implant materials for load bearing applications must be strong enough to support the loads involved in daily activities, and bioinert, to limit reactivity in the body that may cause inflammatory and other adverse reactions. Metal alloys are typically used as materials for load bearing implants and rely on mechanical interlocking to achieve fixation which can be improved by using bone cements. To improve implant osteointegration, metal implants have been coated with a bone-like mineral: hydroxyapatite (HA). The plasma spray technique is commonly used to apply the HA coating. Such implants do not require the use of bone cement. Plasma sprayed HA coated implants are FDA approved and currently on the market, but their properties are not reproducible or reliable. Thus, coating delamination can occur. Our research group developed a novel family of bioactive glasses which were enameled onto titanium alloy using a functionally graded approach. We stratified the coating with different glass compositions to fulfill different functions. We coupled a first glass layer, with a good CTE match to the alloy, with a second layer of bioactive glass obtaining a functionally graded bioactive coating (FGC). In this thesis for the first time the cytocompatibility of novel bioactive glasses, and their functionally graded coatings on Ti6Al4V, was studied with an in vitro bone model (MC3T3-E1.4 mouse preosteblast cells). The novel bioactive glasses are cytocompatible and no compositional change is required. The fabrication process is reproducible, introduces a small (average 6 vol%) amount of crystallization, which does not significantly affect bioactivity in SBF as tested. The coatings are

Temporary ovarian suppression during chemotherapy to preserve ovarian function and fertility in breast cancer patients: A GRADE approach for evidence evaluation and recommendations by the Italian Association of Medical Oncology.

Science.gov (United States)

Lambertini, Matteo; Cinquini, Michela; Moschetti, Ivan; Peccatori, Fedro A; Anserini, Paola; Valenzano Menada, Mario; Tomirotti, Maurizio; Del Mastro, Lucia

2017-01-01

The development of premature ovarian failure and subsequent infertility are possible consequences of chemotherapy use in pre-menopausal women with early-stage breast cancer. Among the available strategies for fertility preservation, pharmacological protection of the ovaries using luteinising hormone-releasing hormone analogues (LHRHa) during chemotherapy has the potential to restore ovarian function and fertility after anticancer treatments; however, the possible efficacy and clinical application of this strategy has been highly debated in the last years. Following the availability of new data on this controversial topic, the Panel of the Italian Association of Medical Oncology (AIOM) Clinical Practice Guideline on fertility preservation in cancer patients decided to apply the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methodology around the relevant and current question on the clinical utility of temporary ovarian suppression with LHRHa during chemotherapy as a strategy to preserve ovarian function and fertility in breast cancer patients. To answer this question, preservation of ovarian function and fertility were judged as critical outcomes for the decision-making. Three possible outcomes of harm were identified: LHRHa-associated toxicities, potential antagonism between concurrent LHRHa and chemotherapy, and lack of the prognostic impact of chemotherapy-induced premature ovarian failure. According to the GRADE evaluation conducted, the result was a strong positive recommendation in favour of using this option to preserve ovarian function and fertility in breast cancer patients. The present manuscript aims to update and summarise the evidence for the use of this strategy in light of the new data published up to January 2016, according to the GRADE process. Copyright © 2016 Elsevier Ltd. All rights reserved.

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2015. Scientific Opinion on the substantiation of a health claim related to vitamin D and contribution to the normal function of the immune system pursuant to Article 14 of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

2015-01-01

on the scientific substantiation of a health claim related to vitamin D and contribution to the normal function of the immune system. The Panel considers that vitamin D is sufficiently characterised. Contribution to the normal function of the immune system is a beneficial physiological effect for children....... The Panel had previously assessed a claim on vitamin D and contribution to the normal function of the immune system with a favourable outcome. The target population was the general population. The Panel considered that vitamin D plays a regulatory role in the functioning of the immune system. The Panel...... considers that the role of vitamin D in the functioning of the immune system applies to all ages, including children. The Panel concludes that a cause and effect relationship has been established between the dietary intake of vitamin D and contribution to the normal function of the immune system...

Deflection control of functionally graded material beams with bonded piezoelectric sensors and actuators

International Nuclear Information System (INIS)

Gharib, Ahmad; Salehi, Manouchehr; Fazeli, Saeed

2008-01-01

An analytical solution is developed for analysis of functionally graded material (FGM) beams containing two layers of piezoelectric material, used as sensor and actuator. The properties of FGM layer are functionally graded in the thickness direction according to the volume fraction power law distribution. The equations of motion are derived by using Hamilton's principle, based on the first-order shear deformation theory. By using a displacement potential function, and assumption of harmonic vibration, the equations of motion have been solved analytically. Finally, the effects of FGM constituent volume fraction in the peak responses for various volume fraction indexes have been graphically illustrated

Transient Stress Intensity Factors of Functionally Graded Hollow Cylinders with Internal Circumferential Cracks

Directory of Open Access Journals (Sweden)

Iman Eshraghi

Full Text Available Abstract In this paper, transient thermomechanical stress intensity factors for functionally graded cylinders with complete internal circumferential cracks are obtained using the weight function method. The finite difference method is used to calculate the time dependent temperature distribution and thermal stresses along the cylinder thickness. Furthermore, finite element analysis is performed to determine the weight function coefficients and to investigate the accuracy of the predicted stress intensity factors from the weight functions. Variation of the stress intensity factors with time and effects of the material gradation on the results are investigated, as well. It is shown that the proposed technique can be used to accurately predict transient thermomechanical stress intensity factors for functionally graded cylinders with arbitrary material gradation.

A simple and accurate grading system for orthoiodohippurate renal scans in the assessment of post-transplant renal function

International Nuclear Information System (INIS)

Zaki, S.K.; Bretan, P.N.; Go, R.T.; Rehm, P.K.; Streem, S.B.; Novick, A.C.

1990-01-01

Orthoiodohippurate renal scanning has proved to be a reliable, noninvasive method for the evaluation and followup of renal allograft function. However, a standardized system for grading renal function with this test is not available. We propose a simple grading system to distinguish the different functional phases of hippurate scanning in renal transplant recipients. This grading system was studied in 138 patients who were evaluated 1 week after renal transplantation. There was a significant correlation between the isotope renographic functional grade and clinical correlates of allograft function such as the serum creatinine level (p = 0.0001), blood urea nitrogen level (p = 0.0001), urine output (p = 0.005) and need for hemodialysis (p = 0.007). We recommend this grading system as a simple and accurate method to interpret orthoiodohippurate renal scans in the evaluation and followup of renal allograft recipients

Tailoring vibration mode shapes using topology optimization and functionally graded material concepts

International Nuclear Information System (INIS)

Rubio, Wilfredo Montealegre; Paulino, Glaucio H; Silva, Emilio Carlos Nelli

2011-01-01

Tailoring specified vibration modes is a requirement for designing piezoelectric devices aimed at dynamic-type applications. A technique for designing the shape of specified vibration modes is the topology optimization method (TOM) which finds an optimum material distribution inside a design domain to obtain a structure that vibrates according to specified eigenfrequencies and eigenmodes. Nevertheless, when the TOM is applied to dynamic problems, the well-known grayscale or intermediate material problem arises which can invalidate the post-processing of the optimal result. Thus, a more natural way for solving dynamic problems using TOM is to allow intermediate material values. This idea leads to the functionally graded material (FGM) concept. In fact, FGMs are materials whose properties and microstructure continuously change along a specific direction. Therefore, in this paper, an approach is presented for tailoring user-defined vibration modes, by applying the TOM and FGM concepts to design functionally graded piezoelectric transducers (FGPT) and non-piezoelectric structures (functionally graded structures—FGS) in order to achieve maximum and/or minimum vibration amplitudes at certain points of the structure, by simultaneously finding the topology and material gradation function. The optimization problem is solved by using sequential linear programming. Two-dimensional results are presented to illustrate the method

Microstructure, mechanical properties, and biological response to functionally graded HA coatings

International Nuclear Information System (INIS)

Rabiei, Afsaneh; Blalock, Travis; Thomas, Brent; Cuomo, Jerry; Yang, Y.; Ong, Joo

2007-01-01

Hydroxyapatite (HA) [Ca 10 (PO 4 ) 6 (OH) 2 ] is the primary mineral content, representing 43% by weight, of bone. Applying a thin layer of HA, to the surface of a metal implant, can promote osseointegration and increase the mechanical stability of the implant. In this study, a biocompatible coating comprising an HA film with functionally graded crystallinity is being deposited on a heated substrate in an Ion Beam Assisted Deposition (IBAD) system. The microstructure of the film was studied using Transmission Electron Microscopy techniques. Finally, initial cell adhesion and cell differentiation on the coating was evaluated using ATCC CRL 1486 human embryonic palatal mesenchymal cell, an osteoblast precursor cell line. The results have shown superior mechanical properties and biological response to the functionally graded HA film

Inter-hemispheric language functional reorganization in low-grade glioma patients after tumour surgery

NARCIS (Netherlands)

Kristo, Gert; Raemaekers, Mathijs; Rutten, Geert-Jan; de Gelder, Beatrice; Ramsey, Nick F.

Despite many claims of functional reorganization following tumour surgery, empirical studies that investigate changes in functional activation patterns are rare. This study investigates whether functional recovery following surgical treatment in patients with a low-grade glioma in the left

Inter-hemispheric language functional reorganization in low-grade glioma patients after tumour surgery

NARCIS (Netherlands)

Kristo, Gert; Raemaekers, Mathijs; Rutten, Geert Jan; de Gelder, Beatrice; Ramsey, Nick F.

2015-01-01

Despite many claims of functional reorganization following tumour surgery, empirical studies that investigate changes in functional activation patterns are rare. This study investigates whether functional recovery following surgical treatment in patients with a low-grade glioma in the left

Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure

Directory of Open Access Journals (Sweden)

Liying Jiang

2011-12-01

Full Text Available In this work, the problem of a curved functionally graded piezoelectric (FGP actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.

Thermo-Electro-Mechanical Analysis of a Curved Functionally Graded Piezoelectric Actuator with Sandwich Structure.

Science.gov (United States)

Yan, Zhi; Zaman, Mostafa; Jiang, Liying

2011-12-12

In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g 31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.

Air pollution and lung function among susceptible adult subjects: a panel study

Directory of Open Access Journals (Sweden)

Marconi Achille

2006-05-01

Full Text Available Abstract Background Adverse health effects at relatively low levels of ambient air pollution have consistently been reported in the last years. We conducted a time-series panel study of subjects with chronic obstructive pulmonary disease (COPD, asthma, and ischemic heart disease (IHD to evaluate whether daily levels of air pollutants have a measurable impact on the lung function of adult subjects with pre-existing lung or heart diseases. Methods Twenty-nine patients with COPD, asthma, or IHD underwent repeated lung function tests by supervised spirometry in two one-month surveys. Daily samples of coarse (PM10–2.5 and fine (PM2.5 particulate matter were collected by means of dichotomous samplers, and the dust was gravimetrically analyzed. The particulate content of selected metals (cadmium, chrome, iron, nickel, lead, platinum, vanadium, and zinc was determined by atomic absorption spectrometry. Ambient concentrations of nitrogen dioxide (NO2, carbon monoxide (CO, ozone (O3, and sulphur dioxide (SO2 were obtained from the regional air-quality monitoring network. The relationships between concentrations of air pollutants and lung function parameters were analyzed by generalized estimating equations (GEE for panel data. Results Decrements in lung function indices (FVC and/or FEV1 associated with increasing concentrations of PM2.5, NO2 and some metals (especially zinc and iron were observed in COPD cases. Among the asthmatics, NO2 was associated with a decrease in FEV1. No association between average ambient concentrations of any air pollutant and lung function was observed among IHD cases. Conclusion This study suggests that the short-term negative impact of exposure to air pollutants on respiratory volume and flow is limited to individuals with already impaired respiratory function. The fine fraction of ambient PM seems responsible for the observed effects among COPD cases, with zinc and iron having a potential role via oxidative stress. The

Teaching Mathematical Functions Using Geometric Functions Approach and Its Effect on Ninth Grade Students' Motivation

Science.gov (United States)

Akçakin, Veysel

2018-01-01

The purpose of this study is to investigate the effects of using geometric functions approach on 9th grade students' motivation levels toward mathematics in functions unit. Participants of this study were 87 students who were ongoing in the first year of high school in Turkey. In this research, pretest and posttest control group quasiexperimental…

Graded-index fibers, Wigner-distribution functions, and the fractional Fourier transform.

Science.gov (United States)

Mendlovic, D; Ozaktas, H M; Lohmann, A W

1994-09-10

Two definitions of a fractional Fourier transform have been proposed previously. One is based on the propagation of a wave field through a graded-index medium, and the other is based on rotating a function's Wigner distribution. It is shown that both definitions are equivalent. An important result of this equivalency is that the Wigner distribution of a wave field rotates as the wave field propagates through a quadratic graded-index medium. The relation with ray-optics phase space is discussed.

Correlation of grading of pulmonary emphysema by computed tomography to pulmonary function

International Nuclear Information System (INIS)

Yamagishi, Masahiko; Mori, Masaki; Hirai, Hideyuki; Mori, Yuji; Koba, Hiroyuki; Suzuki, Akira

1988-01-01

We studied the CT findings of 17 emphysema patients with special reference to the extent of emphysematous changes. Characteristic CT findings were low-attenuation area (LAA) and vascular abnormality and the appearance of various images on CT. To assess the extent of emphysematous changes, we classified the CT images into 4 grades based on the distribution and size of LAAs. As the grades progressed, the distribution and size of LAAs became wider and larger and vascular abnormalities were clearly evident. Although this CT-grading is a semiquantitative method, it is simple to use and gives information on the approximate extent of disease. This CT-grading was also used to show pulmonary function. The RV/TLC and expiratory flow showed a tendency to be impaired in Grade IV and the diffusion capacity was impaired parallel to CT-grading. CT is able to demonstrate the presence and distribution of LAAs noninvasively. Therefore it is considered that CT is useful for clinical diagnosis and the assessment of the extent of pulmonary emphysema. (author)

Performance Analysis of Functionally Graded Coatings in Contact with Cylindrical Rollers

Directory of Open Access Journals (Sweden)

Reza Jahedi

2015-01-01

Full Text Available This work presents finite element analysis (FEA and results for rolling contact of a cylindrical roller on an elastic substrate coated by functionally graded material (FGM. The rolling process and the graded coating material property and layers arrangement are modeled using finite element codes which lead to a new methodology. This novel methodology provides a trend in determining surface contact stresses, deformations, contact zones, and energy dissipation through the contact area. Effects of stiffness ratio, friction, and exponentially variation of material property on the contact stresses and deformations are studied. Some of the results are verified with analytical solutions. The study results may be beneficial in graded coated cylindrical components analysis against rolling contact failure and wear.

Free Vibration and Stability of Axially Functionally Graded Tapered Euler-Bernoulli Beams

Directory of Open Access Journals (Sweden)

Ahmad Shahba

2011-01-01

Full Text Available Structural analysis of axially functionally graded tapered Euler-Bernoulli beams is studied using finite element method. A beam element is proposed which takes advantage of the shape functions of homogeneous uniform beam elements. The effects of varying cross-sectional dimensions and mechanical properties of the functionally graded material are included in the evaluation of structural matrices. This method could be used for beam elements with any distributions of mass density and modulus of elasticity with arbitrarily varying cross-sectional area. Assuming polynomial distributions of modulus of elasticity and mass density, the competency of the element is examined in stability analysis, free longitudinal vibration and free transverse vibration of double tapered beams with different boundary conditions and the convergence rate of the element is then investigated.

Finite Element Analysis of the Deformation of Functionally Graded Plates under Thermomechanical Loads

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A. E. Alshorbagy

2013-01-01

Full Text Available The first-order shear deformation plate model, accounting for the exact neutral plane position, is exploited to investigate the uncoupled thermomechanical behavior of functionally graded (FG plates. Functionally graded materials are mainly constructed to operate in high temperature environments. Also, FG plates are used in many applications (such as mechanical, electrical, and magnetic, where an amount of heat may be generated into the FG plate whenever other forms of energy (electrical, magnetic, etc. are converted into thermal energy. Several simulations are performed to study the behavior of FG plates, subjected to thermomechanical loadings, and focus the attention on the effect of the heat source intensity. Most of the previous studies have considered the midplane neutral one, while the actual position of neutral plane for functionally graded plates is shifted and should be firstly determined. A comparative study is performed to illustrate the effect of considering the neutral plane position. The volume fraction of the two constituent materials of the FG plate is varied smoothly and continuously, as a continuous power function of the material position, along the thickness of the plate.

Rayleigh wave behavior in functionally graded magneto-electro-elastic material

Science.gov (United States)

Ezzin, Hamdi; Mkaoir, Mohamed; Amor, Morched Ben

2017-12-01

Piezoelectric-piezomagnetic functionally graded materials, with a gradual change of the mechanical and electromagnetic properties have greatly applying promises. Based on the ordinary differential equation and stiffness matrix methods, a dynamic solution is presented for the propagation of the wave on a semi-infinite piezomagnetic substrate covered with a functionally graded piezoelectric material (FGPM) layer. The materials properties are assumed to vary in the direction of the thickness according to a known variation law. The phase and group velocity of the Rayleigh wave is numerically calculated for the magneto-electrically open and short cases, respectively. The effect of gradient coefficients on the phase velocity, group velocity, coupled magneto-electromechanical factor, on the stress fields, the magnetic potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the hetero-structure PZT-5A/CoFe2O4; the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Rayleigh wave propagation behavior.

Suitability of the double Langevin function for description of anhysteretic magnetization curves in NO and GO electrical steel grades

Directory of Open Access Journals (Sweden)

Simon Steentjes

2017-05-01

Full Text Available This paper compares the match obtained using the classical Langevin function, the tanh function as well as a recently by the authors proposed double Langevin function with the measured anhysteretic magnetization curve of three different non-oriented electrical steel grades and one grain-oriented grade. Two standard non-oriented grades and a high-silicon grade (Si content of 6.5% made by CVD are analyzed. An excellent match is obtained using the double Langevin function, whereas the classical solutions are less appropriate. Thereby, problems such as those due to propagation of approximation errors observed in hysteresis modeling can be bypassed.

Investigation of free vibration analysis of functionally graded annular piezoelectric plate using COMSOL

Science.gov (United States)

Sharma, Trivendra Kumar; Parashar, Sandeep Kumar

2018-05-01

In the present age functionally graded piezoelectric materials (FGPM) are increasingly being used as actuators and sensors. In spite of the fact that the piezoelectric coupling coefficient for shear d15 has much higher value in comparison to d31 or d33, it is far less utilized for the applications due to complex nature of the shear induced vibrations. In this work three dimensional free vibration analysis of functionally graded piezoelectric material annular plates with free-free boundary conditions is presented. The annular FGPM plate is polarized along the radial direction while the electric field is applied along the thickness direction inducing flexural vibrations of the plate due to d15 effect of functionally graded piezoelectric materials. The material properties are assumed to have a power law variation along the thickness. COMSOL Multiphysics is used to obtain the natural frequencies and modeshapes. Detailed numerical study is performed to ascertain the effect of variation in power law index and various geometrical parameters. The results presented shall be helpful in optimizing the existing applications and developing the new ones utilizing the FGPM annular plates.

Thermal and mechanical stresses in a functionally graded thick sphere

International Nuclear Information System (INIS)

Eslami, M.R.; Babaei, M.H.; Poultangari, R.

2005-01-01

In this paper, a general solution for the one-dimensional steady-state thermal and mechanical stresses in a hollow thick sphere made of functionally graded material is presented. The temperature distribution is assumed to be a function of radius, with general thermal and mechanical boundary conditions on the inside and outside surfaces of the sphere. The material properties, except Poisson's ratio, are assumed to vary along the radius r according to a power law function. The analytical solution of the heat conduction equation and the Navier equation lead to the temperature profile, radial displacement, radial stress, and hoop stress as a function of radial direction

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

International Nuclear Information System (INIS)

Watanabe, Yoshimi; Shibuya, Masafumi; Sato, Hisashi

2013-01-01

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

Deposition and Characterization of HVOF Thermal Sprayed Functionally Graded Coatings Deposited onto a Lightweight Material

Science.gov (United States)

Hasan, M.; Stokes, J.; Looney, L.; Hashmi, M. S. J.

2009-02-01

There is a significant interest in lightweight materials (like aluminum, magnesium, titanium, and so on) containing a wear resistance coating, in such industries as the automotive industry, to replace heavy components with lighter parts in order to decrease vehicle weight and increase fuel efficiency. Functionally graded coatings, in which the composition, microstructure, and/or properties vary gradually from the bond coat to the top coat, may be applied to lightweight materials, not only to decrease weight, but also to enhance components mechanical properties by ensuring gradual microstructural (changes) together with lower residual stress. In the current work, aluminum/tool-steel functionally graded coatings were deposited onto lightweight aluminum substrates. The graded coatings were then characterized in terms of residual stress and hardness. Results show that residual stress increased with an increase in deposition thickness and a decrease in number of layers. However, the hardness also increased with an increase in deposition thickness and decrease in number of layers. Therefore, an engineer must compromise between the hardness and stress values while designing a functionally graded coating-substrate system.

Three-Dimensional Finite Element Modeling of Thermomechanical Problems in Functionally Graded Hydroxyapatite/Titanium Plate

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S. N. S. Jamaludin

2014-01-01

Full Text Available The composition of hydroxyapatite (HA as the ceramic phase and titanium (Ti as the metallic phase in HA/Ti functionally graded materials (FGMs shows an excellent combination of high biocompatibility and high mechanical properties in a structure. Because the gradation of these properties is one of the factors that affects the response of the functionally graded (FG plates, this paper is presented to show the domination of the grading parameter on the displacement and stress distribution of the plates. A three-dimensional (3D thermomechanical model of a 20-node brick quadratic element is used in the simulation of the thermoelastic behaviors of HA/Ti FG plates subjected to constant and functional thermal, mechanical, and thermomechanical loadings. The convergence properties of the present results are examined thoroughly in order to assess the accuracy of the theory applied and to compare them with the established research results. Instead of the grading parameter, this study reveals that the loading field distribution can be another factor that reflects the thermoelastic properties of the HA/Ti FG plates. The FG structure is found to be able to withstand the thermal stresses while preserving the high toughness properties and thus shows its ability to operate at high temperature.

Finite element analysis of functionally graded bone plate at femur bone fracture site

Science.gov (United States)

Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

2018-03-01

This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

A chemometrics study of analytical panels in virgin olive oil. An approach for evaluating panels in training

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Aparicio, R.

1991-06-01

Full Text Available A mathematical procedure including Canonical Correlation, Factor and cluster analysis and Multiple Regression was designed to study whether two different sensory panels, with different levels of training, could be considered as a unity. Among others, correlations between each attribute of both panels, matrices of partial correlations, variance explained by the most important factors and similarity among clusters were computed as the procedure to evaluate if a Panel in training works as well as an expertise. In addition, every one of the factors was correlated with the final evaluation of quality for analyzing the interrelationship between the profile notes and the grading table of virgin olive oil quality from a mathematical point of view. Finally, a stepwise multiple correlation analyzes how the panels modeled the evaluated samples. Promising directions for future research are also suggested.

Un procedimiento matemático que incluye Correlación Canónica, Análisis Factorial y de "clusters", y Regresión Múltiple fue diseñado para estudiar si dos paneles analíticos, con diferentes niveles de entrenamiento, podrían ser considerados idénticos. Para evaluar si un panel en o después de un entrenamiento opera tan bien como uno experto, se analizaron las correlaciones entre los atributos de ambos paneles, las matrices de correlaciones parciales, la varianza explicada por los factores más importantes y la similaridad entre los aglomerados ("clusters" entre otras. Además, los tres factores más importantes fueron correlacionados con las valoraciones finales de calidad, para conocer la interrelación entre la hoja de perfil y la tabla de puntuación. Finalmente, un análisis de regresión múltiple permite conocer cómo es el modelo que los paneles han diseñado para muestras de aceite de oliva virgen evaluadas. También se sugieren las tendencias en la investigación futura.

Emerging role of functional brain MRI in low-grade glioma surgery

DEFF Research Database (Denmark)

Friismose, Ancuta; Traise, Peter; Markovic, Ljubo

Learning objectives 1. To describe the use of functional MRI (fMRI) in cranial surgery planning for patients with low-grade gliomas (LGG). 2. To show the increasing importance of fMRI in the clinical setting. Background LGG include brain tumors classified by the World Health Organization as grade I...... be used to map eloquent cortex areas, thus minimizing postoperative deficits and improving surgical performance. Findings and procedure details Patients diagnosed with low-grade gliomas located in eloquent brain areas undergo fMRI prior to surgery. The exams are performed on a 3T MR system (Achieva TX....... Language comprehension and visual tasks can be added to visualize Wernicke’s area or the visual cortex. Diffusion tensor imaging (DTI) is used to map nerve tract course relative to the tumour. Conclusion FMRI has proven its clinical utility in locating eloquent brain areas with relation to tumor site...

Plane strain analytical solutions for a functionally graded elastic-plastic pressurized tube

International Nuclear Information System (INIS)

Eraslan, Ahmet N.; Akis, Tolga

2006-01-01

Plane strain analytical solutions to functionally graded elastic and elastic-plastic pressurized tube problems are obtained in the framework of small deformation theory. The modulus of elasticity and the uniaxial yield limit of the tube material are assumed to vary radially according to two parametric parabolic forms. The analytical plastic model is based on Tresca's yield criterion, its associated flow rule and ideally plastic material behaviour. Elastic, partially plastic and fully plastic stress states are investigated. It is shown that the elastoplastic response of the functionally graded pressurized tube is affected significantly by the material nonhomogeneity. Different modes of plasticization may take place unlike the homogeneous case. It is also shown mathematically that the nonhomogeneous elastoplastic solution presented here reduces to that of a homogeneous one by appropriate choice of the material parameters

Research on Free Vibration Frequency Characteristics of Rotating Functionally Graded Material Truncated Conical Shells with Eccentric Functionally Graded Material Stringer and Ring Stiffeners

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Dao Van Dung

Full Text Available Abstract In this research work, an exact analytical solution for frequency characteristics of the free vibration of rotating functionally graded material (FGM truncated conical shells reinforced by eccentric FGM stringers and rings has been investigated by the displacement function method. Material properties of shell and stiffeners are assumed to be graded in the thickness direction according to a simple power law distribution. The change of spacing between stringers is considered. Using the Donnell shell theory, Leckhnisky smeared stiffeners technique and taking into account the influences of centrifugal force and Coriolis acceleration the governing equations are derived. For stiffened FGM conical shells, it is difficult that free vibration equations are a couple set of three variable coefficient partial differential equations. By suitable transformations and applying Galerkin method, this difficulty is overcome in the paper. The sixth order polynomial equation for w is obtained and it is used to analyze the frequency characteristics of rotating ES-FGM conical shells. Effects of stiffener, geometrics parameters, cone angle, vibration modes and rotating speed on frequency characteristics of the shell forward and backward wave are discussed in detail. The present approach proves to be reliable and accurate by comparing with published results available in the literature.

Bending, Buckling and Vibration of a Functionally Graded Porous Beam Using Finite Elements

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Noha Fouda

2017-10-01

Full Text Available This study presents the effect of porosity on mechanical behaviors of a power distribution functionally graded beam. The Euler-Bernoulli beam is assumed to describe the kinematic relations and constitutive equations. Because of technical problems, particle size shapes and micro-voids are created during the fabrication which should be taken into consideration. Two porosity models are proposed. The first one describes properties in the explicit form as linear functions of the porosity parameter. The second is a modified model which presents porosity and Young’s modulus in an implicit form where the density is assumed as a function of the porosity parameter and Young’s modulus as a ratio of mass with porosity to the mass without porosity. The modified proposed model is more applicable than the first model. The finite element model is developed to solve the problem by using the MATLAB software. Numerical results are presented to show the effects of porosity on mechanical behaviors of functionally graded beams.

Continuous functionally graded porous titanium scaffolds manufactured by selective laser melting for bone implants.

Science.gov (United States)

Han, Changjun; Li, Yan; Wang, Qian; Wen, Shifeng; Wei, Qingsong; Yan, Chunze; Hao, Liang; Liu, Jie; Shi, Yusheng

2018-04-01

A significant requirement for a bone implant is to replicate the functional gradient across the bone to mimic the localization change in stiffness. In this work, continuous functionally graded porous scaffolds (FGPSs) based on the Schwartz diamond unit cell with a wide range of graded volume fraction were manufactured by selective laser melting (SLM). The micro-topology, strut dimension characterization and effect of graded volume fraction on the mechanical properties of SLM-processed FGPSs were systematically investigated. The micro-topology observations indicate that diamond FGPSs with a wide range of graded volume fraction from 7.97% to 19.99% were fabricated without any defects, showing a good geometric reproduction of the original designs. The dimensional characterization demonstrates the capability of SLM in manufacturing titanium diamond FGPSs with the strut size of 483-905µm. The elastic modulus and yield strength of the titanium diamond FGPSs can be tailored in the range of 0.28-0.59GPa and 3.79-17.75MPa respectively by adjusting the graded volume fraction, which are comparable to those of the cancellous bone. The mathematical relationship between the graded porosity and compression properties of a FGPS was revealed. Furthermore, two equations based on the Gibson and Ashby model have been established to predict the modulus and yield strength of SLM-processed diamond FGPSs. Compared to homogeneous diamond porous scaffolds, FGPSs provide a wide range of mutative pore size and porosity, which are potential to be tailored to optimize the pore space for bone tissue growth. The findings provide a basis of new methodologies to design and manufacture superior graded scaffolds for bone implant applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

Science.gov (United States)

Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

2018-05-01

This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

Investigation of trapped thickness-twist waves induced by functionally graded piezoelectric material in an inhomogeneous plate

International Nuclear Information System (INIS)

Li, Peng; Jin, Feng; Cao, Xiao-Shan

2013-01-01

The effect of functional graded piezoelectric materials on the propagation of thickness-twist waves is investigated through equations of the linear theory of piezoelectricity. The elastic and piezoelectric coefficients, dielectric permittivity, and mass density are assumed to change in a linear form but with different graded parameters along the wave propagation direction. We employ the power-series technique to solve the governing differential equations with variable coefficients attributed to the different graded parameters and prove the correction and convergence of this method. As a special case, the functional graded middle layer resulting from piezoelectric damage and material bonding is investigated. Piezoelectric damaged material can facilitate energy trapping, which is impossible in perfect materials. The increase in the damaged length and the reduction in the piezoelectric coefficient decrease the resonance frequency but increase the number of modes. Higher modes of thickness-twist waves appear periodically along the damaged length. Moreover, the displacement of the center of the damaged portion is neither symmetric nor anti-symmetric, unlike the non-graded plate. The conclusions are theoretically and practically significant for wave devices. (paper)

Biomarker discovery in high grade sarcomas by mass spectrometry imaging

OpenAIRE

Lou, S.

2017-01-01

This thesis demonstrates a detailed biomarker discovery Mass Spectrometry Imaging workflow for histologically heterogeneous high grade sarcomas. Panels of protein and metabolite signatures were discovered either distinguishing different histological subtypes or stratifying high risk patients with poor survival.

Optimisation of energy absorbing liner for equestrian helmets. Part II: Functionally graded foam liner

International Nuclear Information System (INIS)

Cui, L.; Forero Rueda, M.A.; Gilchrist, M.D.

2009-01-01

The energy absorbing liner of safety helmets was optimised using finite element modelling. In this present paper, a functionally graded foam (FGF) liner was modelled, while keeping the average liner density the same as in a corresponding reference single uniform density liner model. Use of a functionally graded foam liner would eliminate issues regarding delamination and crack propagation between interfaces of different density layers which could arise in liners with discrete density variations. As in our companion Part I paper [Forero Rueda MA, Cui L, Gilchrist MD. Optimisation of energy absorbing liner for equestrian helmets. Part I: Layered foam liner. Mater Des [submitted for publication

Panel Data Evidence on the Demand for Money

OpenAIRE

Serletis, Apostolos; Vaccaro, Jason

2006-01-01

This paper examines the demand for money using panel data for 48 countries over the 1980-95 time period. In our examination of the conventional money demand function, we begin by empirically exploiting traditional panel methodology and fi nd support for heterogeneity among the countries. However, specifi cation and diagnostic tests also indicate serial correlation in all of the estimated models. Recent state-of-the art advances in panel unit root and panel cointegration methodology allow us t...

Identifying Professional Development Needs in Mathematics: A Planning Tool for Grades 3-7. Second Edition

Science.gov (United States)

Taylor, Mary Jo; Dimino, Joseph A.; Gellar, Leanne Ketterlin; Koontz, Trish

2010-01-01

This document offers a planning tool for grades 3-7 that can be used by regional comprehensive centers, other technical assistance centers, and state departments of education to plan professional development for teachers. It is based on the "National Mathematics Advisory Panel Report" which was published in 2008. The panel synthesized its final…

Bamboo-inspired optimal design for functionally graded hollow cylinders.

Directory of Open Access Journals (Sweden)

Motohiro Sato

Full Text Available The optimal distribution of the reinforcing fibers for stiffening hollow cylindrical composites is explored using the linear elasticity theory. The spatial distribution of the vascular bundles in wild bamboo, a nature-designed functionally graded material, is the basis for the design. Our results suggest that wild bamboos maximize their flexural rigidity by optimally regulating the radial gradation of their vascular bundle distribution. This fact provides us with a plant-mimetic design principle that enables the realization of high-stiffness and lightweight cylindrical composites.

Plutonium Finishing Plant (PFP) Criticality Alarm System Commercial Grade Item (CGI) Critical Characteristics

International Nuclear Information System (INIS)

WHITE, W.F.

1999-01-01

This document specifies the critical characteristics for Commercial Grade Items (CGI) procured for PFP's criticality alarm system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to properly perform its safety function. There may be several manufacturers or models that meet the critical characteristics for any one item. PFP's Criticality Alarm System includes the nine criticality alarm system panels and their associated hardware. This includes all parts up to the first breaker in the electrical distribution system. Specific system boundaries and justifications are contained in HNF-SD-CP-SDD-003, ''Definition and Means of Maintaining the Criticality Detectors and Alarms Portion of the PFP Safety Envelope.'' The procurement requirements associated with the system necessitates procurement of some system equipment as Commercial Grade Items in accordance with HNF-PRO-268, ''Control of Purchased Items and Services.''

Late evaluation of the relationship between morphological and functional renal changes and hypertension after non-operative treatment of high-grade renal injuries

Directory of Open Access Journals (Sweden)

Pereira Júnior Gerson

2012-08-01

Full Text Available Abstract Objective To evaluate the anatomical and functional renal alterations and the association with post-traumatic arterial hypertension. Methods The studied population included patients who sustained high grades renal injury (grades III to V successfully non-operative management after staging by computed tomography over a 16-year period. Beyond the review of medical records, these patients were invited to the following protocol: clinical and laboratory evaluation, abdominal computed tomography, magnetic resonance angiography, DMSA renal scintigraphy, and ambulatory blood pressure monitoring. The hypertensive patients also were submitted to dynamic renal scintigraphy (99mTc EC, using captopril stimulation to verify renal vascular etiology. Results Of the 31 patients, there were thirteen grade III, sixteen grade IV (nine lacerations, and seven vascular lesions, and two grade V injuries. All the patients were asymptomatic and an average follow up post-injury of 6.4 years. None had abnormal BUN or seric creatinine. The percentage of renal volume reduction correlates with the severity as defined by OIS. There was no evidence of renal artery stenosis in Magnetic Resonance angiography (MRA. DMSA scanning demonstrated a decline in percentage of total renal function corresponding to injury severity (42.2 ± 5.5% for grade III, 35.3 ± 12.8% for grade IV, 13.5 ± 19.1 for grade V. Six patients (19.4% had severe compromised function ( Conclusions Late results of renal function after conservative treatment of high grades renal injuries are favorable, except for patients with grades IV with vascular injuries and grade V renal injuries. Moreover, arterial hypertension does not correlate with the grade of renal injury or reduction of renal function.

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

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Li Ming Zhou

2016-01-01

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

77 FR 13389 - Art Advisory Panel of the Commissioner of Internal Revenue

Science.gov (United States)

2012-03-06

... 2512 of the Internal Revenue Code of 1986. In order for the Panel to perform this function, Panel... Administration, has also approved renewal of the Panel. The membership of the Panel is balanced between museum...

Functionally Graded Polyimide Nanocomposite Foams for Ablative and Inflatable/Flexible/Deplorable Structures, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of the proposed research is to develop functionally graded polyimide foams as light-weight, high performance thermal protection systems (TPS) for...

Fundamentals of liquid phase for modern cermets and functionally graded cemented carbonitrides (FGCC)

International Nuclear Information System (INIS)

Chen, L.; Lengauer, W.; Ettmayer, P.; Dreyer, K.; Daub, H.W.; Kassel, D.

2001-01-01

Metallurgical reactions and microstructure developments during sintering of modern cermets and functionally graded cemented carbonitrides (FGCC) were investigated by modern thermal and analytical methods such as mass spectrometer (MS), differential thermal analysis (DTA), differential scanning calorimeter (DSC), dilatometer (DIL), microscopy and analytical electronic microscopy with energy dispersive spectrometer (EDS). The complex phase reactions and phase equilibrium in the multi-component system Ti/Mo/W/Ta/Nb/C,N-Co/Ni were studied. The melting behaviors in the systems of TiC-WC/MoC-Ni/Co, TiC-TiN-WC-Co and TiCN-TaC-WC-Co have been established. By better understanding of the mechanisms that govern the sintering processing and metallurgical reactions, new cermets and different types of functionally graded cemented carbonitrides (FGCC) with desired microstructures and properties were developed and fabricated. (author)

Functionally graded hardmetals and cermets: preparation, performance and production scale up

International Nuclear Information System (INIS)

Dreyer, K.; Kassel, D.; Daub, H.-W.; Berg, H. van den; Lengauer, W.; Garcia, J.; Ucakar, V.

2001-01-01

Sintering experiments were carried out to establish graded microstructures in hardmetals and cermets. The formation of these microstructural features was investigated as a function of nitrogen pressure, sintering temperature, sintering period and sintering profile. The nitrogen pressure influences the formation of carbonitride layers at the surface. Decreasing sintering temperature yields similar results as increasing nitrogen pressure. Upon prolonged sintering time a small growth of the outer carbonitride layer can only be obtained if a substantial WC grain growth is accepted. Variation of the sintering profile after dense sintering does not principally change the type of the graded microstructure. The laboratory experiments were scaled up in an industrial sinter/HIP furnace and showing good correspondence with each other. First turning cutting tests with different alloys show excellent performance in comparison to ungraded materials. (author)

A New Hyperbolic Shear Deformation Theory for Bending Analysis of Functionally Graded Plates

Directory of Open Access Journals (Sweden)

Tahar Hassaine Daouadji

2012-01-01

Full Text Available Theoretical formulation, Navier’s solutions of rectangular plates based on a new higher order shear deformation model are presented for the static response of functionally graded plates. This theory enforces traction-free boundary conditions at plate surfaces. Shear correction factors are not required because a correct representation of transverse shearing strain is given. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Numerical illustrations concern flexural behavior of FG plates with metal-ceramic composition. Parametric studies are performed for varying ceramic volume fraction, volume fractions profiles, aspect ratios, and length to thickness ratios. Results are verified with available results in the literature. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded plates.

Thermal Change for Photovoltaic Panels and Energy Effects

OpenAIRE

İmal, Nazım; Hasar, Şahabettin; Çınar, Harun; Şener, Eralp

2015-01-01

Photovoltaic panels (solar cells), they receive photon energy from sunlight, convert them to electrical energy by the semiconductor structural features. Photovoltaic panels produce a voltage, depending on the change of functional sunlight exposure. Produced voltage and determining of provided electrical power, must be dealt with the physical parameters that uses the concepts of light and temperature. In this study, usage of monocrystalline and polycrystalline structured photovoltaic panels el...

Transient response of rotating laminated functionally graded cylindrical shells in thermal environment

International Nuclear Information System (INIS)

Malekzadeh, P.; Heydarpour, Y.; Haghighi, M.R. Golbahar; Vaghefi, M.

2012-01-01

Based on the elasticity theory, the transient analysis of dynamically pressurized rotating multi-layered functionally graded (FG) cylindrical shells in thermal environment is presented. The variations of the field variables across the shell thickness are accurately modeled by dividing the shell into a set of co-axial mathematical layers in the radial direction. The initial thermo-mechanical stresses are obtained by solving the thermoelastic equilibrium equations. The differential quadrature method and Newmark's time integration scheme are employed to discretize the obtained governing equations of each mathematical layer. After performing the convergence and comparison studies, parametric studies for two common types of FG sandwich shells, namely, the shell with homogeneous inner/outer layers and FG core and the shell with FG inner/outer layers and homogeneous core are carried out. The influences of the temperature dependence of material properties, material graded index, the convective heat transfer coefficient, the angular velocity, the boundary condition and the geometrical parameters (length and thickness to outer radius ratios) on the dynamic response of the FG shells are investigated. Highlights: ► As a first endeavor, transient analysis of rotating laminated functionally graded cylinders. ► Employing an elasticity based discrete layer-differential quadrature method. ► Evaluating and including the initial thermo-mechanical stresses accurately. ► Considering the temperature-dependence of the material properties. ► Presenting some new results, which can be used as benchmark solution for future works.

An accurate higher order displacement model with shear and normal deformations effects for functionally graded plates

Energy Technology Data Exchange (ETDEWEB)

Jha, D.K., E-mail: dkjha@barc.gov.in [Civil Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Kant, Tarun [Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400 076 (India); Srinivas, K. [Civil Engineering Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Singh, R.K. [Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2013-12-15

Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature.

An accurate higher order displacement model with shear and normal deformations effects for functionally graded plates

International Nuclear Information System (INIS)

Jha, D.K.; Kant, Tarun; Srinivas, K.; Singh, R.K.

2013-01-01

Highlights: • We model through-thickness variation of material properties in functionally graded (FG) plates. • Effect of material grading index on deformations, stresses and natural frequency of FG plates is studied. • Effect of higher order terms in displacement models is studied for plate statics. • The benchmark solutions for the static analysis and free vibration of thick FG plates are presented. -- Abstract: Functionally graded materials (FGMs) are the potential candidates under consideration for designing the first wall of fusion reactors with a view to make best use of potential properties of available materials under severe thermo-mechanical loading conditions. A higher order shear and normal deformations plate theory is employed for stress and free vibration analyses of functionally graded (FG) elastic, rectangular, and simply (diaphragm) supported plates. Although FGMs are highly heterogeneous in nature, they are generally idealized as continua with mechanical properties changing smoothly with respect to spatial coordinates. The material properties of FG plates are assumed here to vary through thickness of plate in a continuous manner. Young's modulii and material densities are considered to be varying continuously in thickness direction according to volume fraction of constituents which are mathematically modeled here as exponential and power law functions. The effects of variation of material properties in terms of material gradation index on deformations, stresses and natural frequency of FG plates are investigated. The accuracy of present numerical solutions has been established with respect to exact three-dimensional (3D) elasticity solutions and the other models’ solutions available in literature

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

Directory of Open Access Journals (Sweden)

Zhang Zhongtao

2008-08-01

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

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014 . Scientific Opinion on the substantiation of a health claim related to zinc and normal function of the immune system pursuant to Article 14 of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

substantiation of a health claim related to zinc and normal function of the immune system. The food constituent, zinc, which is the subject of the health claim is sufficiently characterised. Normal function of the immune system is a beneficial physiological effect for infants and young children. A claim on zinc...... and function of the immune system in the general population has already been assessed with a favourable outcome. The Panel considers that the role of zinc in normal function of the immune system applies to all ages, including infants and young children (from birth to three years). The Panel concludes...... that a cause and effect relationship has been established between the dietary intake of zinc and normal function of the immune system. The following wording reflects the scientific evidence: “zinc contributes to normal function of the immune system”....

Three-dimensional free vibration of functionally graded truncated conical shells subjected to thermal environment

Energy Technology Data Exchange (ETDEWEB)

Malekzadeh, P., E-mail: p_malekz@yahoo.com [Department of Mechanical Engineering, Persian Gulf University, Bushehr 75168 (Iran, Islamic Republic of); Fiouz, A.R.; Sobhrouyan, M. [Department of Civil Engineering, Persian Gulf University, Bushehr 75168 (Iran, Islamic Republic of)

2012-01-15

A three-dimensional (3D) free vibration analysis of the functionally graded (FG) truncated conical shells subjected to thermal environment is presented. The material properties are assumed to be temperature-dependent and graded in the radius direction, which can vary according to a simple power law distribution. The initial thermal stresses are obtained accurately by solving the thermoelastic equilibrium equations and by considering the two-dimensional axisymmetric temperature distribution in the shell. The differential quadrature method (DQM) as an efficient and accurate numerical tool is adopted to solve the thermal and thermo-mechanical governing equations. For this purpose, a mapping technique is employed to transform the cross section of the shell into the computational domain of DQM. The convergence behavior of the method is numerically demonstrated and comparison studies with the available solutions in the literature are performed. The effects of temperature dependence of material properties, geometrical parameters, material graded index, thermal and mechanical boundary conditions on the frequency parameters of the FG truncated conical shells are carried out. - Highlights: Black-Right-Pointing-Pointer 3D free vibration analysis of the functionally graded truncated conical shells is presented. Black-Right-Pointing-Pointer Two-dimensional axisymmetric temperature distribution in the shell is assumed. Black-Right-Pointing-Pointer The material properties are assumed to be temperature-dependent. Black-Right-Pointing-Pointer Initial thermal stresses due to thermal environment are evaluated accurately and included. Black-Right-Pointing-Pointer Representing the effects of different parameters on the non-dimensional frequencies.

Edge-Spread Functions Expected for Several Changes in a Commercial Flat-Panel System

International Nuclear Information System (INIS)

Schach von Wittenau, A E

2002-01-01

The Bldg. 239 radiography facility uses a 9 MeV bremsstrahlung linac and a commercially available fiat-panel detector system. Ref. [1] discusses the facility in detail. Ref. [1] furthermore discusses the imaging quality of the fiat-panel system, and identifies several sources of image blur for the system in question. The maim'' contributors to the imaging blur are radiation scattered from the front cover of the detector housing, radiation scattered from the back cover of the detector housing, and radiation scattered from the aluminum plate that supports the amorphous-Si detector within the detector housing. The manufacturer of one such fiat-panel system seems willing to modify one of their products as requested, if such modifications may be made easily. Easy modifications would include making the detector housing thinner, decreasing the sizes of air gaps inside tile detector system, etc. Removing the aluminum support plate is considered to be a difficult modification. This memo reports the results of a set of Monte Carlo simulations that were performed to predict the changes in imaging quality, compared to that of the current system, if the detector is modified as suggested above. In particular, the edge-spread function (ESF) was calculated for each modification. ESFs were calculated for three photon energies: 100 keV, 450 keV, and 3 MeV. The results suggest that thinning and moving tile front and back covers of the detector housing should result in improved image quality for all of the photon energies considered. Interestingly, the results also suggest that removing the aluminum support plate would improve tim imaging performance at 100 keV and 450 keV, but that removing the plate has no additional benefit for imaging with 3 MeV photons

Barrier pillar between production panels in coal mine

Energy Technology Data Exchange (ETDEWEB)

Zingano, Andre Cezar; Koppe, Jair Carlos; Costa, Joao Felipe C.L. [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)

2007-07-01

The function of the barrier pillar is to protect the mining panel in activity from the abutment load of adjacent mining panels that were mined. In the case of underground mines in Santa Catarina State, the barrier pillar has functioned to protect the main entries of the mine against pillar failure from old mining panels. The objective of this paper is to verify the application of the empirical method to design barrier pillars as proposed by Peng (1986), using numerical simulation following the mining geometry of the coal mines in Santa Catarina State. Two-dimensional numerical models were built taking into account the geometry of the main entries and mining panels for different overburden thickness, and considering the geomechanical properties for the rock mass that forms the roof-pillar-floor system for the Bonito coal vein. The results of the simulations showed that the empirical method to determine the barrier pillar width is valid for the studied coal vein and considered mine geometry. Neither did the pillar at the main entry become overstressed due to adjacent mine panels, nor did the roof present any failure due to stress redistribution. 9 refs., 6 figs., 5 tabs.

Cohesive fracture model for functionally graded fiber reinforced concrete

International Nuclear Information System (INIS)

Park, Kyoungsoo; Paulino, Glaucio H.; Roesler, Jeffery

2010-01-01

A simple, effective, and practical constitutive model for cohesive fracture of fiber reinforced concrete is proposed by differentiating the aggregate bridging zone and the fiber bridging zone. The aggregate bridging zone is related to the total fracture energy of plain concrete, while the fiber bridging zone is associated with the difference between the total fracture energy of fiber reinforced concrete and the total fracture energy of plain concrete. The cohesive fracture model is defined by experimental fracture parameters, which are obtained through three-point bending and split tensile tests. As expected, the model describes fracture behavior of plain concrete beams. In addition, it predicts the fracture behavior of either fiber reinforced concrete beams or a combination of plain and fiber reinforced concrete functionally layered in a single beam specimen. The validated model is also applied to investigate continuously, functionally graded fiber reinforced concrete composites.

Cognitive impairments in patients with low grade gliomas and high grade gliomas

Directory of Open Access Journals (Sweden)

Eliane C. Miotto

2011-08-01

Full Text Available OBJECTIVE: The relationship between brain tumors and cognitive deficits is well established in the literature. However, studies investigating the cognitive status in low and high-grade gliomas patients are scarce, particularly in patients with average or lower educational level. This study aimed at investigating the cognitive functioning in a sample of patients with low and high-grade gliomas before surgical intervention. METHOD: The low-grade (G1, n=19 and high-grade glioma (G2, n=8 patients underwent a detailed neuropsychological assessment of memory, executive functions, visuo-perceptive and visuo-spatial abilities, intellectual level and language. RESULTS: There was a significant impairment on verbal and visual episodic memory, executive functions including mental flexibility, nominal and categorical verbal fluency and speed of information processing in G2. G1 showed only specific deficits on verbal and visual memory recall, mental flexibility and processing speed. CONCLUSION: These findings demonstrated different levels of impairments in the executive and memory domains in patients with low and high grade gliomas.

Parametric study of development of Inconel-steel functionally graded materials by laser direct metal deposition

International Nuclear Information System (INIS)

Shah, Kamran; Haq, Izhar ul; Khan, Ashfaq; Shah, Shaukat Ali; Khan, Mushtaq; Pinkerton, Andrew J

2014-01-01

Highlights: • Functionally graded steel and nickel super-alloy structures have been developed. • Mechanical properties of FGMs can be controlled by process input parameters. • SDAS is strongly dependent on the laser power and powder mass flow rate. • Carbides provide a mechanism to control the hardness and wear resistance of FGM. • Tensile strength of FGM is dependent on the laser power and powder mass flow rate. - Abstract: Laser direct metal deposition (LDMD) has developed from a prototyping to a single and multiple metals manufacturing technique. It offers an opportunity to produce graded components, with differing elemental composition, phase and microstructure at different locations. In this work, continuously graded Stainless Steel 316L and Inconel 718 thin wall structures made by direct laser metal deposition process have been explored. The paper considers the effects of process parameters including laser power levels and powder mass flow rates of SS316L and Inconel 718 during the deposition of the Steel–Ni graded structures. Microstructure characterisation and phase identification are performed by optical microscopy and X-ray diffraction techniques. Mechanical testing, using methods such as hardness, wear resistance and tensile testing have been carried out on the structures. XRD results show the presence of the NbC and Fe 2 Nb phases formed during the deposition. The effect of experimental parameters on the microstructure and physical properties are determined and discussed. Work shows that mechanical properties can be controlled by input parameters and generation of carbides provides an opportunity to selectively control the hardness and wear resistance of the functionally graded material

Functionally Graded Ceramics Fabricated with Side-by-Side Tape Casting for Use in Magnetic Refrigeration

DEFF Research Database (Denmark)

Bulatova, Regina; Bahl, Christian; Andersen, Kjeld Bøhm

2015-01-01

Functionally graded ceramic tapes have been fabricated by a side-by-side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small...... variations of solvent and binder system concentrations have a substantial effect on slurry viscosity. Varying these parameters showed that side-by-side tape casting with a well-defined interface area is possible for slurries with viscosities above 3500 mPa s at a casting shear rate of 3.3 s -1...... of developing this graded ceramic tape casting was applications of these specific magnetocaloric properties within the magnetic refrigeration technology....

Environmental Knowledge and Beliefs among Grade 10 Students in Australia.

Science.gov (United States)

Eyers, Vivian George

To develop environmental education in Australia, a survey of tenth-grade students was undertaken. Thirty knowledge items and ten belief items were constructed. A panel of environmentalists and educators identified best responses for the knowledge items, and a common reference point, preservation of homo sapiens, for the belief items, so a…

Inter-hemispheric language functional reorganization in low-grade glioma patients after tumour surgery.

Science.gov (United States)

Kristo, Gert; Raemaekers, Mathijs; Rutten, Geert-Jan; de Gelder, Beatrice; Ramsey, Nick F

2015-03-01

Despite many claims of functional reorganization following tumour surgery, empirical studies that investigate changes in functional activation patterns are rare. This study investigates whether functional recovery following surgical treatment in patients with a low-grade glioma in the left hemisphere is linked to inter-hemispheric reorganization. Based on literature, we hypothesized that reorganization would induce changes in the spatial pattern of activation specifically in tumour homologue brain areas in the healthy right hemisphere. An experimental group (EG) of 14 patients with a glioma in the left hemisphere near language related brain areas, and a control group of 6 patients with a glioma in the right, non-language dominant hemisphere were scanned before and after resection. In addition, an age and gender matched second control group of 18 healthy volunteers was scanned twice. A verb generation task was used to map language related areas and a novel technique was used for data analysis. Contrary to our hypothesis, we found that functional recovery following surgery of low-grade gliomas cannot be linked to functional reorganization in language homologue brain areas in the healthy, right hemisphere. Although elevated changes in the activation pattern were found in patients after surgery, these were largest in brain areas in proximity to the surgical resection, and were very similar to the spatial pattern of the brain shift following surgery. This suggests that the apparent perilesional functional reorganization is mostly caused by the brain shift as a consequence of surgery. Perilesional functional reorganization can however not be excluded. The study suggests that language recovery after transient post-surgical language deficits involves recovery of functioning of the presurgical language system. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of medical guide wire of Cu-Al-Mn-base superelastic alloy with functionally graded characteristics.

Science.gov (United States)

Sutou, Yuji; Omori, Toshihiro; Furukawa, Akihisa; Takahashi, Yukinori; Kainuma, Ryosuke; Yamauchi, Kiyoshi; Yamashita, Shuzo; Ishida, Kiyohito

2004-04-15

A new type of medical guide wire with functionally graded hardness from the tip to the end was developed with the use of Cu-Al-Mn-based alloys. The superelasticity (SE) of the Cu-Al-Mn-based alloys in the tip is drastically improved by controlling the grain size, whereas the end of the wire is hardened using bainitic transformation by aging at around 200-400 degrees C. Therefore, the tip of the guide wire shows a superelasticity and its end has high stiffness. This guide wire with functionally graded characteristics shows excellent pushability and torquability, superior to that of the Ni-Ti guide wire. Copyright 2004 Wiley Periodicals, Inc.

Volumetric Nephrogram Represents Renal Function and Complements Aortic Anatomic Severity Grade in Predicting EVAR Outcomes.

Science.gov (United States)

Balceniuk, Mark D; Trakimas, Lauren; Aghaie, Claudia; Mix, Doran; Rasheed, Khurram; Seaman, Matthew; Ellis, Jennifer; Glocker, Roan; Doyle, Adam; Stoner, Michael C

2018-07-01

Chronic kidney disease (CKD) is a predictor of poor outcomes for patients undergoing endovascular aortic aneurysm repair (EVAR). Anatomic severity grade (ASG) represents a quantitative mechanism for assessing anatomical suitability for endovascular aortic repair. Anatomic severity grade has been correlated with repair outcomes and resource utilization. The purpose of this study was to identify a novel renal perfusion metric as a way to assist ASG with predicting EVAR outcomes. Retrospective review of a prospectively maintained database identified elective infrarenal aortic aneurysm repair cases. Anatomic grading was undertaken by independent reviewers. Using volumetric software, kidney volume, and a novel measure of kidney functional volume, the volumetric nephrogram (VN) was recorded. Systematic evaluation of the relationship of kidney volume and VN to CKD and ASG was undertaken using linear regression and receiver-operator statistical tools. A total of 386 cases with patient and anatomic data were identified and graded. Mean age was 72.9 ± 0.4 years. Renal volume renal volume (AUC = .628; P ≤ .0001) and VN (AUC = .628; P ≤ .0001). Regression analysis demonstrated a strong, inverse relationship between ASG and VN ( R 2 = .95). These data demonstrate that VN is a strong predictor of CKD in a large database of patients undergoing elective aneurysm repair. We demonstrate an inverse relationship between renal function and ASG that has not been previously described in the literature. Additionally, we have shown that VN complements ASG as a model of overall cardiovascular health and atherosclerotic burden. Outcomes in patients with poor renal function may be related to anatomical issues in addition to well-described systemic ramifications.

The Effect of Material Property on the Critical Velocity of Randomly Excited Nonlinear Axially Travelling Functionally Graded Plates

Directory of Open Access Journals (Sweden)

M. Abedi

Full Text Available Abstract In this paper, the critical axial speeds of three types of sigmoid, power law and exponential law functionally graded plates for both isotropic and orthotropic cases are obtained via a completely analytic method. The plates are subjected to lateral white noise excitation and show evidence of large deformations. Due to randomness, the conventional deterministic methods fail and a statistical approach must be selected. Here, the probability density function is evaluated analytically for prescribed plates and used to investigate the critical axial velocity of them. Specifically the effect of in-plane forces, mean value of lateral load and the material property on the critical axial speed are studied and discussed for both isotropic and orthotropic functionally graded plates. Since the governing equation is transformed to a non dimensional format, the results can be used for a wide range of plate dimensions. It is shown that the material heterogeneity palys an essential and significant role in increasing or decreasing the critical speed of both isotropic and orthotropic functionally graded plates.

Electrodeposition of Ni–W–Al{sub 2}O{sub 3} nanocomposite coating with functionally graded microstructure

Energy Technology Data Exchange (ETDEWEB)

Allahyarzadeh, M.H.; Aliofkhazraei, M., E-mail: maliofkh@gmail.com; Rouhaghdam, A.R. Sabour; Torabinejad, V.

2016-05-05

Electrodeposition of functionally graded (FG) Ni–W–Al{sub 2}O{sub 3} nanocomposite coatings is investigated in current research. These types of coatings were applied in a way that alumina content was increased from the substrate towards the surface of the coating; hence, Ni–W would possess improved wear and corrosion resistance properties. FG-coatings were developed by the variation of duty cycle and frequency. The microstructure and elemental analysis of the coating as a function of thickness was investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis, respectively. The corrosion resistance of the FG-coatings was evaluated using potentiodynamic polarization and the wear behavior was also studied using pin-on-disk wear tests. In order to investigate hardness properties of the coating, microhardness measurements were carried out on cross-section of coatings. Results revealed that the alumina content and the microhardness increased towards the surface. Results also showed the corrosion and wear resistance of FG-coatings were significantly improved by addition of α-Al{sub 2}O{sub 3} nanoparticles. Profilometery and AFM results also revealed that surface roughness was influenced by pulse plating parameters. - Highlights: • Functionally graded structures have been synthesized using adjusting pulse parameters. • Al{sub 2}O{sub 3} and W contents increases gradually as a function of coating thickness. • Alumina increased the corrosion resistance by moderating i{sub corr} and E{sub corr}. • Wear behavior has been enhanced in functionally graded structure.

Is the Sky Falling? Grade Inflation and the Signaling Power of Grades.

Science.gov (United States)

Pattison, Evangeleen; Grodsky, Eric; Muller, Chandra

2013-06-01

Grades are the fundamental currency of our educational system; they signal academic achievement and non-cognitive skills to parents, employers, postsecondary gatekeepers, and students themselves. Grade inflation compromises the signaling value of grades, undermining their capacity to achieve the functions for which they are intended. We challenge the 'increases in grade point average' definition of grade inflation and argue that grade inflation must be understood in terms of the signaling power of grades. Analyzing data from four nationally representative samples, we find that in the decades following 1972: (a) grades have risen at high schools and dropped at four-year colleges, in general, and selective four-year institutions, in particular; and (b) the signaling power of grades has attenuated little, if at all.

FSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Guidance on the scientific requirements for health claims related to functions of the ne rvous system, including psycholog ical functions

DEFF Research Database (Denmark)

Tetens, Inge

The European Food Safety Authority (EFSA) asked the Panel on Dietetic Products, Nutrition and Allergies to draft guidance on scientific requirements for health claims related to functions of the nervous system, including psychological functions. This guidance has been drawn from scientific opinions......, and was released for public consultation from 17 October 2011 to 16 December 2011....

Aerospace Safety Advisory Panel

Science.gov (United States)

1999-01-01

This report covers the activities of the Aerospace Safety Advisory Panel (ASAP) for calendar year 1998-a year of sharp contrasts and significant successes at NASA. The year opened with the announcement of large workforce cutbacks. The slip in the schedule for launching the International Space Station (ISS) created a five-month hiatus in Space Shuttle launches. This slack period ended with the successful and highly publicized launch of the STS-95 mission. As the year closed, ISS assembly began with the successful orbiting and joining of the Functional Cargo Block (FGB), Zarya, from Russia and the Unity Node from the United States. Throughout the year, the Panel maintained its scrutiny of NASA's safety processes. Of particular interest were the potential effects on safety of workforce reductions and the continued transition of functions to the Space Flight Operations Contractor. Attention was also given to the risk management plans of the Aero-Space Technology programs, including the X-33, X-34, and X-38. Overall, the Panel concluded that safety is well served for the present. The picture is not as clear for the future. Cutbacks have limited the depth of talent available. In many cases, technical specialties are 'one deep.' The extended hiring freeze has resulted in an older workforce that will inevitably suffer significant departures from retirements in the near future. The resulting 'brain drain' could represent a future safety risk unless appropriate succession planning is started expeditiously. This and other topics are covered in the section addressing workforce. The major NASA programs are also limited in their ability to plan property for the future. This is of particular concern for the Space Shuttle and ISS because these programs are scheduled to operate well into the next century. In the case of the Space Shuttle, beneficial and mandatory safety and operational upgrades are being delayed because of a lack of sufficient present funding. Likewise, the ISS has

Development of virtual touch panel system for operation at KEK-Electron Linac

International Nuclear Information System (INIS)

Kudou, T.; Kusano, S.; Furukawa, K.; Kamikubota, N.; Satoh, M.

2004-01-01

At the KEK Electron Linac, various operator interfaces are employed to keep its stable operation. Among these, the touch-panel system has been used to manipulate each equipment. However, maintenance of the touch-panel system became difficult for various reasons. A new operator interface on X Window was developed as a virtual touch-panel system with an improved operator interface. All the functions which are used in the old system were already ported. It is designed so that a new function can be added flexibly. The architecture of those old and new touch panel systems is described. (author)

Panel Analysis

DEFF Research Database (Denmark)

Brænder, Morten; Andersen, Lotte Bøgh

2014-01-01

Based on our 2013-article, ”Does Deployment to War Affect Soldiers' Public Service Motivation – A Panel Study of Soldiers Before and After their Service in Afghanistan”, we present Panel Analysis as a methodological discipline. Panels consist of multiple units of analysis, observed at two or more...... in research settings where it is not possible to distribute units of analysis randomly or where the independent variables cannot be manipulated. The greatest disadvantage in regard to using panel studies is that data may be difficult to obtain. This is most clearly vivid in regard to the use of panel surveys...... points in time. In comparison with traditional cross-sectional studies, the advantage of using panel studies is that the time dimension enables us to study effects. Whereas experimental designs may have a clear advantage in regard to causal inference, the strength of panel studies is difficult to match...

Solar Panel based Milk Pasteurization

DEFF Research Database (Denmark)

Nielsen, Kirsten Mølgaard; Pedersen, Tom Søndergaard

This paper treats the subject of analysis, design and development of the control system for a solar panel based milk pasteurization system to be used in small villages in Tanzania. The analysis deals with the demands for an acceptable pasteurization, the varying energy supply and the low cost, low...... complexity, simple user interface and high reliability demands. Based on these demands a concept for the pasteurization system is established and a control system is developed. A solar panel has been constructed and the energy absorption has been tested in Tanzania. Based on the test, the pasteurization...... system is dimensioned. A functional prototype of the pasteurization facility with a capacity of 200 l milk/hour has been developed and tested. The system is prepared for solar panels as the main energy source and is ready for a test in Tanzania....

Solar Panel based Milk Pasteurization

DEFF Research Database (Denmark)

Nielsen, Kirsten Mølgaard; Pedersen, Tom Søndergaard

2002-01-01

This paper treats the subject of analysis, design and development of the control system for a solar panel based milk pasteurization system to be used in small villages in Tanzania. The analysis deals with the demands for an acceptable pasteurization, the varying energy supply and the low cost, low...... complexity, simple user interface and high reliability demands. Based on these demands a concept for the pasteurization system is established and a control system is developed. A solar panel has been constructed and the energy absorption has been tested in Tanzania. Based on the test, the pasteurization...... system is dimensioned. A functional prototype of the pasteurization facility with a capacity of 200 l milk/hour has been developed and tested. The system is prepared for solar panels as the main energy source and is ready for a test in Tanzania....

Decomposing University Grades: A Longitudinal Study of Students and Their Instructors

Science.gov (United States)

Beenstock, Michael; Feldman, Dan

2018-01-01

First-degree course grades for a cohort of social science students are matched to their instructors, and are statistically decomposed into departmental, course, instructor, and student components. Student ability is measured alternatively by university acceptance scores, or by fixed effects estimated using panel data methods. After controlling for…

The Effects of a Reader's Theater Instructional Intervention on Second Grade Students' Reading Fluency and Comprehension Skills

Science.gov (United States)

Johnson, Diane D.

2011-01-01

An estimated 75% of students who are poor readers in third grade continue to be lower achieving readers in ninth grade. The National Reading Panel has identified fluency as a prominent cause of reading comprehension problems which ultimately affect overall reading development. The purpose of this study was to test the theoretical framework of…

Dynamic chest radiography: flat-panel detector (FPD) based functional X-ray imaging.

Science.gov (United States)

Tanaka, Rie

2016-07-01

Dynamic chest radiography is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. The large field of view (FOV) of FPDs permits real-time observation of the entire lungs and simultaneous right-and-left evaluation of diaphragm kinetics. Most importantly, dynamic chest radiography provides pulmonary ventilation and circulation findings as slight changes in pixel value even without the use of contrast media; the interpretation is challenging and crucial for a better understanding of pulmonary function. The basic concept was proposed in the 1980s; however, it was not realized until the 2010s because of technical limitations. Dynamic FPDs and advanced digital image processing played a key role for clinical application of dynamic chest radiography. Pulmonary ventilation and circulation can be quantified and visualized for the diagnosis of pulmonary diseases. Dynamic chest radiography can be deployed as a simple and rapid means of functional imaging in both routine and emergency medicine. Here, we focus on the evaluation of pulmonary ventilation and circulation. This review article describes the basic mechanism of imaging findings according to pulmonary/circulation physiology, followed by imaging procedures, analysis method, and diagnostic performance of dynamic chest radiography.

Explicit Expressions for Solar Panel Equivalent Circuit Parameters Based on Analytical Formulation and the Lambert W-Function

Directory of Open Access Journals (Sweden)

Javier Cubas

2014-06-01

Full Text Available Due to the high dependence of photovoltaic energy efficiency on environmental conditions (temperature, irradiation..., it is quite important to perform some analysis focusing on the characteristics of photovoltaic devices in order to optimize energy production, even for small-scale users. The use of equivalent circuits is the preferred option to analyze solar cells/panels performance. However, the aforementioned small-scale users rarely have the equipment or expertise to perform large testing/calculation campaigns, the only information available for them being the manufacturer datasheet. The solution to this problem is the development of new and simple methods to define equivalent circuits able to reproduce the behavior of the panel for any working condition, from a very small amount of information. In the present work a direct and completely explicit method to extract solar cell parameters from the manufacturer datasheet is presented and tested. This method is based on analytical formulation which includes the use of the Lambert W-function to turn the series resistor equation explicit. The presented method is used to analyze commercial solar panel performance (i.e., the current-voltage–I-V–curve at different levels of irradiation and temperature. The analysis performed is based only on the information included in the manufacturer’s datasheet.

Synthesis and Characterization of Functional Composite Carbon-Geopolymers for Precast Panel Application

Directory of Open Access Journals (Sweden)

Noor Afifah Kharisma

2017-01-01

Full Text Available The purpose of this study is to examine the influence of carbon (C particles as filler (aggregate in the production of geopolymers functional composite for possible precast panel application. Geopolymers was synthesized through alkali activation of metakaolin added with carbon particles relative to the mass of metakaolin. The mixture was cured at 70°C for 2 hours and the resulting composites were stored in open air for 28 days. The bulk density and the apparent porosity of the composites were measured by using Archimedes method. The thermal properties of the samples was examined by using thermal conductivity measurement and differential scanning calorimetry (DSC. The microstructure characterization of the samples were performed by using x-ray diffraction (XRD and Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS.

UC Cooperative Extension sensory analysis panel enhances the quality of California olive oil

Directory of Open Access Journals (Sweden)

Paul Vossen

2008-05-01

Full Text Available California's olive oil industry has evolved from primarily a salvage operation of the table olive industry to a producer of world-class, premium, extra-virgin olive oil. In 1997, UC Cooperative Extension started the first California olive oil taste panel, which was officially recognized by the International Olive Council in 2001. Specific protocols were used to screen potential panelists and train them to identify defects and positive characteristics, identical to 43 other world taste panels. The UCCE panel helped the California Olive Oil Council develop a seal certification program using sensory analysis. Certification provides consumers with assurance that labeled oils are free of defects and warrant the "extra virgin" grade. Sensory evaluation using a unique UCCE profile sheet provides complete and detailed information about specific positive flavor characteristics of olive cultivars grown in California. The UCCE sensory panel has also contributed to a better understanding of the qualities of California olive oil and advancement of the industry by participating in research on pest management, cultural practices and processing.

The functionally graded sintered steel WC-Co-NbC matrix

Energy Technology Data Exchange (ETDEWEB)

Santos, A.A.A.; Silva Junior, J.F. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil)

2009-07-01

Full text: The high speed steels are used for machining, including cutting tools at high speeds because their wear resistance, high temperature properties and excellent hardness. They are ferrous based alloys of the Fe-C-X component system where X represents a group of elements comprising Cr, W or Mo, V and Co. The aim of this work was to study the feasibility of powder metallurgy technique to develop functionally graded alloy material added by WC, Co and NbC. The morphology of the composite powders and sintered MMC were characterized by scanning electron microscopy and XRD measurements. (author)

Dynamic Response of Functionally Graded Carbon Nanotube Reinforced Sandwich Plate

Science.gov (United States)

Mehar, Kulmani; Panda, Subrata Kumar

2018-03-01

In this article, the dynamic response of the carbon nanotube-reinforced functionally graded sandwich composite plate has been studied numerically with the help of finite element method. The face sheets of the sandwich composite plate are made of carbon nanotube- reinforced composite for two different grading patterns whereas the core phase is taken as isotropic material. The final properties of the structure are calculated using the rule of mixture. The geometrical model of the sandwich plate is developed and discretized suitably with the help of available shell element in ANSYS library. Subsequently, the corresponding numerical dynamic responses computed via batch input technique (parametric design language code in ANSYS) of ANSYS including Newmark’s integration scheme. The stability of the sandwich structural numerical model is established through the proper convergence study. Further, the reliability of the sandwich model is checked by comparison study between present and available results from references. As a final point, some numerical problems have been solved to examine the effect of different design constraints (carbon nanotube distribution pattern, core to face thickness ratio, volume fractions of the nanotube, length to thickness ratio, aspect ratio and constraints at edges) on the time-responses of sandwich plate.

Reconstruction of Spectra Using X-ray Flat Panel Detector; Reconstruccion de Espectros de Rayos X Utilizando un Detector Flat Panel

Energy Technology Data Exchange (ETDEWEB)

Gallardo, S.; Querol, A.; Pozuelo, F.; Juste, B.; Rodenas, J.; Verdu, G.

2013-07-01

In this work, we used a flat panel detector with a wedge of PMMA for absorbed dose curve for given working conditions of X-ray tube The relationship between absorbed dose curve recorded by the flat panel and primary X-ray spectrum is defined by a response function that can be obtained using the Monte Carlo method, namely the MCNP5 code. However there are some problems that affect the applicability of this method such as: flat panel characteristics and the characteristics of the physical process (ill-conditioned problem). Both aspects are discussed in this paper.

Supporting public involvement in interview and other panels: a systematic review.

Science.gov (United States)

Baxter, Susan; Clowes, Mark; Muir, Delia; Baird, Wendy; Broadway-Parkinson, Andrea; Bennett, Carole

2017-10-01

Members of the public are increasingly being invited to become members of a variety of different panels and boards. This study aimed to systematically search the literature to identify studies relating to support or training provided to members of the public who are asked to be members of an interview panel. A systematic search for published and unpublished studies was carried out from June to September 2015. The search methods included electronic database searching, reference list screening, citation searching and scrutinizing online sources. We included studies of any design including published and unpublished documents which outlined preparation or guidance relating to public participants who were members of interview panels or representatives on other types of panels or committees. Results were synthesised via narrative methods. Thirty-six documents were included in the review. Scrutiny of this literature highlighted ten areas which require consideration when including members of the public on interview panels: financial resources; clarity of role; role in the interview process; role in evaluation; training; orientation/induction; information needs; terminology; support; and other public representative needs such as timing, accessibility and support with information technology. The results of the review emphasize a range of elements that need to be fully considered when planning the involvement of public participants on interview panels. It highlights potential issues relating to the degree of involvement of public representatives in evaluating/grading decisions and the need for preparation and on-going support. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

A proposed panel of biomarkers of healthy ageing.

Science.gov (United States)

Lara, Jose; Cooper, Rachel; Nissan, Jack; Ginty, Annie T; Khaw, Kay-Tee; Deary, Ian J; Lord, Janet M; Kuh, Diana; Mathers, John C

2015-09-15

There is no criterion reference for assessing healthy ageing and this creates difficulties when conducting and comparing research on ageing across studies. A cardinal feature of ageing is loss of function which translates into wide-ranging consequences for the individual and for family, carers and society. We undertook comprehensive reviews of the literature searching for biomarkers of ageing on five ageing-related domains including physical capability and cognitive, physiological and musculoskeletal, endocrine and immune functions. Where available, we used existing systematic reviews, meta-analyses and other authoritative reports such as the recently launched NIH Toolbox for assessment of neurological and behavioural function, which includes test batteries for cognitive and motor function (the latter described here as physical capability). We invited international experts to comment on our draft recommendations. In addition, we hosted an experts workshop in Newcastle, UK, on 22-23 October 2012, aiming to help capture the state-of-the-art in this complex area and to provide an opportunity for the wider ageing research community to critique the proposed panel of biomarkers. Here we have identified important biomarkers of healthy ageing classified as subdomains of the main areas proposed. Cardiovascular and lung function, glucose metabolism and musculoskeletal function are key subdomains of physiological function. Strength, locomotion, balance and dexterity are key physical capability subdomains. Memory, processing speed and executive function emerged as key subdomains of cognitive function. Markers of the HPA-axis, sex hormones and growth hormones were important biomarkers of endocrine function. Finally, inflammatory factors were identified as important biomarkers of immune function. We present recommendations for a panel of biomarkers that address these major areas of function which decline during ageing. This biomarker panel may have utility in epidemiological

Mothers' Depressive Symptoms and Children's Cognitive and Social Agency: Predicting First-Grade Cognitive Functioning

Science.gov (United States)

Yan, Ni; Dix, Theodore

2016-01-01

Using data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (N = 1,364), the present study supports an agentic perspective; it demonstrates that mothers' depressive symptoms in infancy predict children's poor first-grade cognitive functioning because depressive symptoms…

Functionally graded poly(dimethylsiloxane)/silver nanocomposites with tailored broadband optical absorption

Energy Technology Data Exchange (ETDEWEB)

Nikolaou, P.; Mina, C.; Constantinou, M.; Koutsokeras, L.E.; Constantinides, G. [Research Unit for Nanostructured Materials Systems, Department of Mechanical Engineering and Materials Science and Engineering, PO Box 50329, 3603 Limassol (Cyprus); Lidorikis, E.; Avgeropoulos, A. [Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina (Greece); Kelires, P.C. [Research Unit for Nanostructured Materials Systems, Department of Mechanical Engineering and Materials Science and Engineering, PO Box 50329, 3603 Limassol (Cyprus); Patsalas, P., E-mail: ppats@physics.auth.gr [Physics Department, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

2015-04-30

In this work, we produce functionally graded nanocomposites consisting of silver (Ag) plasmonic nanoparticles (PNPs) supported in a poly(dimethylsiloxane) (PDMS) matrix. PDMS was selected due to its high optical transparency, nontoxicity and ease of use. The Ag PNPs were formed by annealing sputtered Ag ultra-thin films and were subsequently capped by a spin-coated PDMS layer. We investigate the factors that affect their plasmonic behavior, such as the PNP size, the annealing conditions and the surrounding environment. In order to achieve broadband absorption, we developed PDMS/Ag(PNPs) multilayers with graded PNP size. Thus, we demonstrate the significance of the stacking sequence of various plasmonic layers sandwiched between PDMS layers and its potential for tailoring the plasmonic response of multilayer structure. As a demonstration of this approach, we deposited a specially designed multilayer structure, whose optical extinction resembles the solar emission spectrum. - Highlights: • Elastomers are combined with plasmonic nanoparticles. • The plasmonic effects in stratified media are identified. • Broadband absorption similar to solar emission is achieved.

Grade Distribution Modeling within the Bauxite Seams of the Wachangping Mine, China, Using a Multi-Step Interpolation Algorithm

Directory of Open Access Journals (Sweden)

Shaofeng Wang

2017-05-01

Full Text Available Mineral reserve estimation and mining design depend on a precise modeling of the mineralized deposit. A multi-step interpolation algorithm, including 1D biharmonic spline estimator for interpolating floor altitudes, 2D nearest neighbor, linear, natural neighbor, cubic, biharmonic spline, inverse distance weighted, simple kriging, and ordinary kriging interpolations for grade distribution on the two vertical sections at roadways, and 3D linear interpolation for grade distribution between sections, was proposed to build a 3D grade distribution model of the mineralized seam in a longwall mining panel with a U-shaped layout having two roadways at both sides. Compared to field data from exploratory boreholes, this multi-step interpolation using a natural neighbor method shows an optimal stability and a minimal difference between interpolation and field data. Using this method, the 97,576 m3 of bauxite, in which the mass fraction of Al2O3 (Wa and the mass ratio of Al2O3 to SiO2 (Wa/s are 61.68% and 27.72, respectively, was delimited from the 189,260 m3 mineralized deposit in the 1102 longwall mining panel in the Wachangping mine, Southwest China. The mean absolute errors, the root mean squared errors and the relative standard deviations of errors between interpolated data and exploratory grade data at six boreholes are 2.544, 2.674, and 32.37% of Wa; and 1.761, 1.974, and 67.37% of Wa/s, respectively. The proposed method can be used for characterizing the grade distribution in a mineralized seam between two roadways at both sides of a longwall mining panel.

Tc-99m GSA scintigraphy for evaluation of liver function. Correlations with histological grading and staging (new Inuyama classification)

International Nuclear Information System (INIS)

Endo, Ikuyo; Ohashi, Kenjirou; Fukui, Atsushi; Nikai, Akira; Maeyama, Shiro

2001-01-01

To evaluate the parameters of Tc-99m galactosyl human serum albumin (Tc-99m GSA) as indicators of residual liver function by comparing with laboratory data and histological grading and staging. The study population consists of 82 patients with liver diseases including chronic hepatitis (60), compensated liver cirrhosis (12) and decompensated liver cirrhosis (10). Five parameters of Tc-99m GSA (HH 15 , LHL 15 , LHL/HH, ncEI 5 and EI 5 ) were measured and correlated with laboratory data and histological grading, which indicates necro-inflammatory activity, and staging, which indicates fibrosis (New Inuyama Classification). All 5 parameters showed significant correlation with the laboratory data for liver function including serum albumin, platelet count, and prothrombin time. LHL 15 showed a particularly strong correlation with serum albumin, total bilirubin, TTT, ZTT, and prothrombin time. Regarding histological correlation, only LHL 15 showed a significant correlation with both histological grading and staging. HH 15 and LHL/HH revealed significant correlations with staging only. Extraction indexes were not correlated significantly with histological grading and staging. Among the five parameters we tested, LHL 15 is the most potent indicator of liver function. HH 15 , LHL 15 and LHL/HH appear-useful to non-invasive assess histological fibrosis of the liver non-invasively. (author)

Fabrication and characterization of functionally graded Al–SiC nanocomposite by using a novel multistep friction stir processing

International Nuclear Information System (INIS)

Salehi, Mojtaba; Farnoush, Hamidreza; Mohandesi, Jamshid Aghazadeh

2014-01-01

Highlights: • A novel multistep FSP to fabricate functionally-graded bulk nanocomposites. • The composition of FG sample was changed from 18 to 0 wt% SiC along five layers. • The 3.2 times higher hardness than the base metal in FG sample along the thickness. • The 15% enhancement in hardness of FG sample with respect to homogenous sample. • Microhardness and inverse of interparticle spacing was correlated linearly. - Abstract: Functionally graded materials are one of the most promising candidates among advanced materials. However, some challenges still exist in its fabrication methods. The current study aims to produce functionally-graded bulk Al–SiC nanocomposites by a novel multistep friction stir processing (FSP) for the first time. The SiC nanoparticles were packed into a groove on the 6061 aluminum plate and FSP was performed by using a tool with pin length of 6 mm. Subsequently, FSP was reapplied on another groove by using a tool with a shorter pin length of 3.2 mm. The desirable distribution of SiC nanoparticles in the matrix was confirmed by scanning electron and atomic force microscopes. The composition of graded sample was changed continuously from 18 to 0 wt% SiC along the thickness. Accordingly, the microhardness profile showed a maximum of 160 Hv in the enriched zone which is 3.2 times higher than the hardness of the particle-depleted zone. However, a constant hardness value of 135 Hv was obtained along the thickness of homogenous sample which is 15% lower than that of superficial layer in graded sample. Moreover, the hardness values were linearly correlated with the inverse of interparticle spacing

Panel and planar experimental shear behavior of wood panels ...

African Journals Online (AJOL)

Panel shear strength along the thickness and planar shear along the length of wood panels laminated softwood oriented OSB 10 mm thick, conditioned at different moisture contents (anhydrous medium, ambient temperature and humid medium) was measured on standardized test specimens, cut in half lengthwise panel ...

Functionally graded scaffolds for the engineering of interface tissues using hybrid twin screw extrusion/electrospinning technology

Science.gov (United States)

Erisken, Cevat

Tissue engineering is the application of the principles of engineering and life sciences for the development of biological alternatives for improvement or regeneration of native tissues. Native tissues are complex structures with functions and properties changing spatially and temporally, and engineering of such structures requires functionally graded scaffolds with composition and properties changing systematically along various directions. Utilization of a new hybrid technology integrating the controlled feeding, compounding, dispersion, deaeration, and pressurization capabilities of extrusion process with electrospinning allows incorporation of liquids and solid particles/nanoparticles into polymeric fibers/nanofibers for fabrication of functionally graded non-woven meshes to be used as scaffolds in engineering of tissues. The capabilities of the hybrid technology were demonstrated with a series of scaffold fabrication and cell culturing studies along with characterization of biomechanical properties. In the first study, the hybrid technology was employed to generate concentration gradations of beta-tricalcium phosphate (beta-TCP) nanoparticles in a polycaprolactone (PCL) binder, between two surfaces of nanofibrous scaffolds. These scaffolds were seeded with pre-osteoblastic cell line (MC3T3-E1) to attempt to engineer cartilage-bone interface, and after four weeks, the tissue constructs revealed formation of continuous gradations in extracellular matrix akin to cartilage-bone interface in terms of distributions of mineral concentrations and biomechanical properties. In a second demonstration of the hybrid technology, graded differentiation of stem cells was attempted by using insulin, a known stimulator of chondrogenic differentiation, and beta-glycerol phosphate (beta-GP), for mineralization. Concentrations of insulin and beta-GP in PCL were controlled to monotonically increase and decrease, respectively, along the length of scaffolds, which were then seeded

Clinical significance of a proposed lymphoscintigrpahic functional grade system in patients with extremity lymphedema of stage i

International Nuclear Information System (INIS)

Choi, Joan Young; Hwang, Ji Hye; Kim, Dong Ik; Cho, Young Seok; Lee, Su Jin; Choi, Yong; Choe, Yeam Seong; Lee, Kyung Han; Kim, Byung Tae

2005-01-01

We proposed a new lymphoscintigrpahic functional grade (LGr) system in extremity lymphedema, and investigated the association between the LGr and a long-term response to physical therapy in patients with extremity lymphedema of stage I. The subjects were 20 patients with unilateral extremity lymphedema of stage I, who underwent pre-treatment extremity lymphoscintigraphy using Tc-99m antimony sulfur colloid, and were treated by complex decongestive physical therapy (CDPT). A proposed lymphoscintigrpahic functional grade system consisted of LGr 0 to LGr 4 according to the ilioinguinal nodal uptake, amount of dermal backflow, and uptake pattern of main and collateral lymphatics : LGr 0 = normal, LGr 1 = decreased lymphatic function without dermal backflow, LGr 2 = decreased lymphatic function with dermal backflow, LGr 3 = non - visualization of main lymphatics with dermal backflow, and LGr 4 = no significant lymphatic transport from injection site. LGr 2 was divided into 2A and 2B based on the amount of dermal backflow. A physician who is a lymphedema specialist determined the long-term outcome to CDPT with normalized response (NR), good response (GR) and poor response (PR) based on the change of edema volume reduction, skin status and occurrence of dermatolymphangioadenitis after the clinical follow-up for more than 1 year. Therapeutic responses were NR in 2 patients. GR in 9 patients and PR in 9 patients. Baseline LGrs were 1 in 7 patients, 2A in 4 patients, 2B in 5 patients, 3 in 2 patients, and 4 in 2 patients. There was a significant relationship between therapeutic response and LGr (p=0.003). In other words, 10 of 11 patients (91%) with LGr 1 or 2A showed NR. or GR. On the contrary, 8 of 9 patients (89%) with LGr 2B, 3 or 4 showed PR. Patients with unilateral extremity lymphedema of stage I had different lymphoscintigrpahic functional grades. This grade system may be useful to predict the response to physical therapy in such patients

Clinical significance of a proposed lymphoscintigrpahic functional grade system in patients with extremity lymphedema of stage i

Energy Technology Data Exchange (ETDEWEB)

Choi, Joan Young; Hwang, Ji Hye; Kim, Dong Ik; Cho, Young Seok; Lee, Su Jin; Choi, Yong; Choe, Yeam Seong; Lee, Kyung Han; Kim, Byung Tae [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2005-07-01

We proposed a new lymphoscintigrpahic functional grade (LGr) system in extremity lymphedema, and investigated the association between the LGr and a long-term response to physical therapy in patients with extremity lymphedema of stage I. The subjects were 20 patients with unilateral extremity lymphedema of stage I, who underwent pre-treatment extremity lymphoscintigraphy using Tc-99m antimony sulfur colloid, and were treated by complex decongestive physical therapy (CDPT). A proposed lymphoscintigrpahic functional grade system consisted of LGr 0 to LGr 4 according to the ilioinguinal nodal uptake, amount of dermal backflow, and uptake pattern of main and collateral lymphatics : LGr 0 = normal, LGr 1 = decreased lymphatic function without dermal backflow, LGr 2 = decreased lymphatic function with dermal backflow, LGr 3 = non - visualization of main lymphatics with dermal backflow, and LGr 4 = no significant lymphatic transport from injection site. LGr 2 was divided into 2A and 2B based on the amount of dermal backflow. A physician who is a lymphedema specialist determined the long-term outcome to CDPT with normalized response (NR), good response (GR) and poor response (PR) based on the change of edema volume reduction, skin status and occurrence of dermatolymphangioadenitis after the clinical follow-up for more than 1 year. Therapeutic responses were NR in 2 patients. GR in 9 patients and PR in 9 patients. Baseline LGrs were 1 in 7 patients, 2A in 4 patients, 2B in 5 patients, 3 in 2 patients, and 4 in 2 patients. There was a significant relationship between therapeutic response and LGr (p=0.003). In other words, 10 of 11 patients (91%) with LGr 1 or 2A showed NR. or GR. On the contrary, 8 of 9 patients (89%) with LGr 2B, 3 or 4 showed PR. Patients with unilateral extremity lymphedema of stage I had different lymphoscintigrpahic functional grades. This grade system may be useful to predict the response to physical therapy in such patients.

Functional Grammar and Teaching of Reading--A Pedagogy Based on Graded Teaching of College English in China

Science.gov (United States)

Xu, Tuo; Zhang, Beili

2015-01-01

This article discusses the importance of functional grammar and demonstrates its application to the teaching of reading among graded college students. Functional grammar holds that a discourse is composed of two levels: the interior level and the exterior level. Therefore, reading activities involve both linguistic elements and contexts.…

Impact of interfacial imperfection on transverse wave in a functionally graded piezoelectric material structure with corrugated boundaries

Science.gov (United States)

Kumar Singh, Abhishek; Kumar, Santan; Kumari, Richa

2018-03-01

The propagation behavior of Love-type wave in a corrugated functionally graded piezoelectric material layered structure has been taken into account. Concretely, the layered structure incorporates a corrugated functionally graded piezoelectric material layer imperfectly bonded to a functionally graded piezoelectric material half-space. An analytical treatment has been employed to determine the dispersion relation for both cases of electrically open condition and electrically short condition. The phase velocity of the Love-type wave has been computed numerically and its dependence on the wave number has been depicted graphically for a specific type of corrugated boundary surfaces for both said conditions. The crux of the study lies in the fact that the imperfect bonding of the interface, the corrugated boundaries present in the layer, and the material properties of the layer and the half-space strongly influence the phase velocity of the Love-type wave. It can be remarkably noted that the imperfect bonding of the interface reduces the phase velocity of the Love-type wave significantly. As a special case of the problem, it is noticed that the procured dispersion relation for both cases of electrically open and electrically short conditions is in accordance with the classical Love wave equation.

Vasomotor function in rat arteries after ex vivo and intragastric exposure to food-grade titanium dioxide and vegetable carbon particles

DEFF Research Database (Denmark)

Jensen, Ditte Marie; Christophersen, Daniel Vest; Sheykhzade, Majid

2018-01-01

-grade particle exposure on vasomotor function and systemic oxidative stress in an ex vivo study and intragastrically exposed rats.Methods: In an ex vivo study, aorta rings from naive Sprague-Dawley rats were exposed for 30 min to food-grade TiO2 (E171), benchmark TiO2 (Aeroxide P25), food-grade vegetable carbon...... (E153) or benchmark carbon black (Printex 90). Subsequently, the vasomotor function was assessed in wire myographs. In an in vivo study, lean Zucker rats were exposed intragastrically once a week for 10 weeks to vehicle, E171 or E153. Doses were comparable to human daily intake. Vasomotor function...... no differences between groups.Conclusion: Gastrointestinal tract exposure to E171 and E153 was associated with modest albeit statistically significant alterations in the vasocontraction and vasorelaxation responses. Direct particle exposure to aorta rings elicited a similar type of response. The vasomotor...

Optimum design of composite panel with photovoltaic-thermo module. Absorbing effect of cooling panel; Hikari netsu fukugo panel no saiteki sekkei. Reikyaku panel no kyunetsu koka

Energy Technology Data Exchange (ETDEWEB)

Sato, M; Kikuchi, S; Tani, T [Science University of Tokyo, Tokyo (Japan); Kadotani, K; Imaizumi, H [Komatsu Ltd., Tokyo (Japan)

1996-10-27

The composite panel with photovoltaic-thermo module becomes higher in energy-saving than the conventional air-conditioning system by the independent radiational heating and cooling effect obtained when the generating panel using a solar cell module is combined with the heating and cooling panel using a thermo-element module. The output of a solar cell module can be directly used because the solar cell module operates in AC. This paper reports the relation between the absorbed value and power consumption of the cooling panel, while paying attention to the cooling panel. The performance coefficient of the maximum absorbed value from an non-absorbing substance to a cooling panel is 2 to 3. Assume that the cooling panel during non-adiabatic operation is operated using a solar cell module of 800 W/m{sup 2} in solar intensity and 15% in conversion efficiency. The cooling-surface temperature difference is 12.12 K, and the maximum absorbed value of a non-absorbing substance to a cooling panel is 39.12 W/m{sup 2}. The absorbed value of the outer temperature to the cooling panel is 74.4 W/m{sup 2}, and each performance coefficient is 3.26 and 0.62. The absorbed value must be calculated for evaluation from the cooling-surface temperature difference measured directly from the cooling panel. 4 refs., 8 figs., 1 tab.

Free vibration of fully functionally graded carbon nanotube reinforced graphite/epoxy laminates

Science.gov (United States)

Kuo, Shih-Yao

2018-03-01

This study provides the first-known vibration analysis of fully functionally graded carbon nanotube reinforced hybrid composite (FFG-CNTRHC) laminates. CNTs are non-uniformly distributed to reinforce the graphite/epoxy laminates. Some CNT distribution functions in the plane and thickness directions are proposed to more efficiently increase the stiffening effect. The rule of mixtures is modified by considering the non-homogeneous material properties of FFG-CNTRHC laminates. The formulation of the location dependent stiffness matrix and mass matrix is derived. The effects of CNT volume fraction and distribution on the natural frequencies of FFG-CNTRHC laminates are discussed. The results reveal that the FFG layout may significantly increase the natural frequencies of FFG-CNTRHC laminate.

Elaboration of functionally graded materials for plasma facing components of the thermonuclear machines

International Nuclear Information System (INIS)

Autissier, Emmanuel

2014-01-01

The objective of this study was to develop a Functionally Graded Material (FGM) W/Cu to replace the compliance layer (Cu-OFHC) in the plasma facing components of thermonuclear fusion reactor like ITER. The peculiarity of this work is to elaborate these materials without exceeding the melting temperature of copper in order to control its microstructure. The co-sintering is the most attractive solution to achieve this goal. The first phase of this study has been to decrease the sintering temperature of the tungsten to achieve this co-sintering. The elaboration of a Functionally Graded Materials being delicate, thermomechanical calculations were performed in order to determine the number and chemical composition in order to increase the lifespan of Plasma Facing Components. Spark Plasma Sintering conditions were optimized in order to achieve maximum density of W x Cu 1-x composites. The effect of copper content and density of the W x Cu 1-x composites on thermal and mechanical properties was investigated. The SPS conditions were applied for W/CuCrZr assemblies with a compliance layer composed of several interlayers. The importance of time for the integrity of assemblies thereof has been highlighted. The study of the dwell time during W/CuCrZr assembly leads to identify a parameter to characterize the integrity of the interface regardless of the composition and the nature of the layer of compliance. Moreover, the phenomena associated with the formation of the interface assembly have been identified. The interface W/W x Cu 1-x is formed by the extrusion of the copper layer of the W x Cu 1-x inside the tungsten porosities. The W y Cu 1-y /CuCrZr interface is formed by copper migration of CuCrZr layer inside the W y Cu 1-y layer. Finally optimization assembly conditions showed that the mechanical stresses due to the densification of the Functionally Graded Materials can be limited by sintering the FGM before the assembly. (author)

Geometry Design Optimization of Functionally Graded Scaffolds for Bone Tissue Engineering: A Mechanobiological Approach.

Directory of Open Access Journals (Sweden)

Antonio Boccaccio

Full Text Available Functionally Graded Scaffolds (FGSs are porous biomaterials where porosity changes in space with a specific gradient. In spite of their wide use in bone tissue engineering, possible models that relate the scaffold gradient to the mechanical and biological requirements for the regeneration of the bony tissue are currently missing. In this study we attempt to bridge the gap by developing a mechanobiology-based optimization algorithm aimed to determine the optimal graded porosity distribution in FGSs. The algorithm combines the parametric finite element model of a FGS, a computational mechano-regulation model and a numerical optimization routine. For assigned boundary and loading conditions, the algorithm builds iteratively different scaffold geometry configurations with different porosity distributions until the best microstructure geometry is reached, i.e. the geometry that allows the amount of bone formation to be maximized. We tested different porosity distribution laws, loading conditions and scaffold Young's modulus values. For each combination of these variables, the explicit equation of the porosity distribution law-i.e the law that describes the pore dimensions in function of the spatial coordinates-was determined that allows the highest amounts of bone to be generated. The results show that the loading conditions affect significantly the optimal porosity distribution. For a pure compression loading, it was found that the pore dimensions are almost constant throughout the entire scaffold and using a FGS allows the formation of amounts of bone slightly larger than those obtainable with a homogeneous porosity scaffold. For a pure shear loading, instead, FGSs allow to significantly increase the bone formation compared to a homogeneous porosity scaffolds. Although experimental data is still necessary to properly relate the mechanical/biological environment to the scaffold microstructure, this model represents an important step towards

Grading evidence from test accuracy studies: what makes it challenging compared with the grading of effectiveness studies?

Science.gov (United States)

Rogozińska, Ewelina; Khan, Khalid

2017-06-01

Guideline panels need to process a sizeable amount of information to issue a decision on whether to recommend a health technology or not. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) is being frequently applied in guideline development to facilitate this task, typically for the synthesis of effectiveness research. Questions regarding the accuracy of medical tests are ubiquitous, and they temporally precede questions about therapy. However, literature summarising the experience of applying GRADE approach to accuracy evaluations is not as rich as one for effectiveness evidence. Type of study design (cross-sectional), two-dimensional nature of the performance measures (sensitivity and specificity), propensity towards a higher level of between-study heterogeneity, poor reporting of quality features and uncertainty about how best to assess for publication bias among other features make this task challenging. This article presents solutions adopted to addresses above challenges for judicious estimation of the strength of test accuracy evidence used to inform evidence syntheses for guideline development. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Thermal behavior of the duct applied functionally graded material

Energy Technology Data Exchange (ETDEWEB)

Park, Jung Sun; Yoon, Dong Young; Im, Jong Bin [Hankuk Aviation Univ., Goyang (Korea, Republic of)

2004-07-01

In Unmanned Aerial Vehicles (UAV), the high temperature results from friction among the air, combustion of fuel in engine and combustion gas of a nozzle. The high temperature may cause serious damages in UAV structure. The Functionally Graded Material(FGM) is chosen as a material of the engine duct structure. Thermal stress analysis of FGM is performed in this paper. FGM is composed of two constituent materials that are mixed up according to the specific volume fraction distribution in order to withstand high temperature. Therefore, hoop stress, axial stress and shear stress of duct with 2 layers, 4 layers and 8 layers FGM are compared and analyzed respectively. In addition, the creep behavior of FGM used in duct structure of an engine is analyzed for better understanding of FGM characteristics.

BWR plant advanced central control panel PODIA

International Nuclear Information System (INIS)

Fujii, K.; Hayakawa, H.; Ikeda, Y.; Neda, T.; Suto, O.; Takamiya, S.

1983-01-01

BWR plant central control panels have become more and more enlarged and complicated recently due to the magnification of the scale of a plant and the requirement to reinforce safety. So, it is important to make communication between men and the complicated central control panel smooth. Toshiba has developed an advanced central control panel, named PODIA, which uses many computers and color CRTs, and PODIA is now in the stage of application to practical plants. In this article, the writers first touch upon control functions transition in the central control room, the PODIA position concerning the world-wide trend in this technology phase and the human engineering on the design. Then they present concrete design concepts for the control board and computer system which constitute PODIA

Corrosion and wear behavior of functionally graded Al2024/SiC composites produced by hot pressing and consolidation

Energy Technology Data Exchange (ETDEWEB)

Erdemir, Fatih; Canakci, Aykut, E-mail: aykut@ktu.edu.tr; Varol, Temel; Ozkaya, Serdar

2015-09-25

Highlights: • Functionally graded Al2024/SiC composites were produced by hot pressing. • Effect of the number of graded layers was investigated on the corrosion behavior. • Functionally graded composites has the most corrosion resistant than composites. • Wear mechanisms of Al2024/SiC composites were explained. - Abstract: Functionally graded Al2024/SiC composites (FGMs) with varying percentage of SiC (30–60%) were produced by hot pressing and consolidation method. The effects of SiC content and number of layers of Al2024/SiC FGMs on the corrosion and wear behaviors were investigated. The microstructures of these composites were characterized by a scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS). The corrosion performances of composites were evaluated by potentiodynamic polarization scans in 3.5% NaCl solution. Corrosion experiments shows that corrosion rate (1109 mpy) of two layered FGMs which containing 50 wt.% SiC were much higher than Al2024 matrix (2569 mpy) and Al2024/50 wt.% SiC composite (2201 mpy). Mechanical properties of these composites were evaluated by microhardness measurements and ball-on-disk wear tests. As the applied load change from 15 to 20 N, the wear rates of the Al2024 increased significantly and wear mechanism transformed from mild to severe wear regime. It has been shown that Al2024/40 wt.% SiC composite has lower wear rate where adhesive and abrasive wear mechanisms play a major role.

Automatic ranging circuit for a digital panel meter

International Nuclear Information System (INIS)

Mueller, T.R.; Ross, H.H.

1976-01-01

This invention relates to a range changing circuit that operates in conjunction with a digital panel meter of fixed sensitivity. The circuit decodes the output of the panel meter and uses that information to change the gain of an input amplifier to the panel meter in order to ensure that the maximum number of significant figures is always displayed in the meter. The circuit monitors five conditions in the meter and responds to any of four combinations of these conditions by means of logic elements to carry out the function of the circuit. The system was designed for readout of a fluorescence analyzer for uranium analysis

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

Science.gov (United States)

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

2011-04-01

A numerical matrix method relative to the propagation of ultrasonic guided waves in functionally graded piezoelectric heterostructure is given in order to make a comparative study with the respective performances of analytical methods proposed in literature. The preliminary obtained results show a good agreement, however numerical approach has the advantage of conceptual simplicity and flexibility brought about by the stiffness matrix method. The propagation behaviour of Love waves in a functionally graded piezoelectric material (FGPM) is investigated in this article. It involves a thin FGPM layer bonded perfectly to an elastic substrate. The inhomogeneous FGPM heterostructure has been stratified along the depth direction, hence each state can be considered as homogeneous and the ordinary differential equation method is applied. The obtained solutions are used to study the effect of an exponential gradient applied to physical properties. Such numerical approach allows applying different gradient variation for mechanical and electrical properties. For this case, the obtained results reveal opposite effects. The dispersive curves and phase velocities of the Love wave propagation in the layered piezoelectric film are obtained for electrical open and short cases on the free surface, respectively. The effect of gradient coefficients on coupled electromechanical factor, on the stress fields, the electrical potential and the mechanical displacement are discussed, respectively. Illustration is achieved on the well known heterostructure PZT-5H/SiO(2), the obtained results are especially useful in the design of high-performance acoustic surface devices and accurately prediction of the Love wave propagation behaviour. Copyright © 2010 Elsevier B.V. All rights reserved.

Estimating a Smooth Common Transfer Function with a Panel of Time Series - Inflow of Larvae Cod as an Example

Directory of Open Access Journals (Sweden)

Elizabeth Hansen

2012-07-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} The annual response variable in an ecological monitoring study often relates linearly to the weighted cumulative effect of some daily covariate, after adjusting for other annual covariates. Here we consider the problem of non-parametrically estimating the weights involved in computing the aforementioned cumulative effect, with a panel of short and contemporaneously correlated time series whose responses share the common cumulative effect of a daily covariate. The sequence of (unknown daily weights constitutes the so-called transfer function. Specifically, we consider the problem of estimating a smooth common transfer function shared by a panel of short time series that are contemporaneously correlated. We propose an estimation scheme using a likelihood approach that penalizes the roughness of the common transfer function. We illustrate the proposed method with a simulation study and a biological example of indirectly estimating the spawning date distribution of North Sea cod.

Mode Shape Analysis of Multiple Cracked Functionally Graded Timoshenko Beams

Directory of Open Access Journals (Sweden)

Tran Van Lien

Full Text Available Abstract The present paper addresses free vibration of multiple cracked Timoshenko beams made of Functionally Graded Material (FGM. Cracks are modeled by rotational spring of stiffness calculated from the crack depth and material properties vary according to the power law throughout the beam thickness. Governing equations for free vibration of the beam are formulated with taking into account actual position of the neutral plane. The obtained frequency equation and mode shapes are used for analysis of the beam mode shapes in dependence on the material and crack parameters. Numerical results validate usefulness of the proposed herein theory and show that mode shapes are good indication for detecting multiple cracks in Timoshenko FGM beams.

Elastic Stress Analysis of Rotating Functionally Graded Annular Disk of Variable Thickness Using Finite Difference Method

Directory of Open Access Journals (Sweden)

Mohammad Hadi Jalali

2018-01-01

Full Text Available Elastic stress analysis of rotating variable thickness annular disk made of functionally graded material (FGM is presented. Elasticity modulus, density, and thickness of the disk are assumed to vary radially according to a power-law function. Radial stress, circumferential stress, and radial deformation of the rotating FG annular disk of variable thickness with clamped-clamped (C-C, clamped-free (C-F, and free-free (F-F boundary conditions are obtained using the numerical finite difference method, and the effects of the graded index, thickness variation, and rotating speed on the stresses and deformation are evaluated. It is shown that using FG material could decrease the value of radial stress and increase the radial displacement in a rotating thin disk. It is also demonstrated that increasing the rotating speed can strongly increase the stress in the FG annular disk.

Synthesis, Characterization And Modeling Of Functionally Graded Multifunctional Hybrid Composites For Extreme Environments

Science.gov (United States)

2017-04-04

Conference on Advanced Computational Engineering and Experimenting(ACE-X2010) July 8-9, 2010, Hotel Concordia La Fayette, Paris, France. 4. J. N...Multifunctional and Functionally Graded Materials, Oct. 19-22, 2014, Taua Resort, SP, Brazil . 25. Reddy, J. N., “Non-classical Theories of Beams...Guest and Plenary Lecture, the Fourth International Symposium on Solid Mechanics - MecSol 2013, Porto Alegre, Rio Grande do Sul, Brazil , 18-19 April

Thermal spraying of functionally graded calcium phosphate coatings for biomedical implants

Science.gov (United States)

Wang, Y.; Khor, K. A.; Cheang, P.

1998-03-01

Biomedical requirements in a prosthesis are often complex and diverse in nature. Biomaterials for implants have to display a wide range of adaptability to suit the various stages of the bio-integration process of any foreign material into the human body. Often, a combination of materials is needed. The preparation of a functionally graded bioceramic coating composed of essentially calcium phosphate compounds is explored. The coating is graded in accordance to adhesive strength, bioactivity, and bioresorbability. The bond coat on the Ti-6Al-4V stub is deposited with a particle range of the hydroxyapatite (HA) that will provide a high adhesive strength and bioactivity but have poor bioresorption properties. The top coat, however, is composed of predominantly α-tricalcium phosphate (α-TCP) that is highly bioresorbable. This arrangement has the propensity of allowing accelerated bio-integration of the coating by the body tissues as the top layer is rapidly resorbed, leaving the more bioactive intermediate layer to facilitate the much needed bioactive properties for proper osteoconduction. The processing steps and problems are highlighted, as well as the results of post-spray heat treatment.

75 FR 8190 - Art Advisory Panel of the Commissioner of Internal Revenue Service

Science.gov (United States)

2010-02-23

... function, Panel records and discussions must include tax return information. Therefore, the Panel meetings... balanced between museum directors and curators, art dealers and auction representatives to afford differing...

Stressed skin panels

Energy Technology Data Exchange (ETDEWEB)

Anon

2001-07-01

Advantages and disadvantages of stressed skin panels, also known as structural insulated panels (SIPs), are discussed as material and labour-saving alternatives to traditional stick framing. Stressed skin panels are manufactured 'sandwich' assemblies with a rigid insulating polystyrene foam core, whose interior and exterior surfaces are bonded into panels. The skins distribute and carry the structural loading while the bonded foam core provides insulation and keeps the two skins aligned. Since there are fewer framing members, there is little thermal bridging and the R-value remains high. SIPs are usually manufactured in four feet by eight feet panels, although some manufacturers can produce panels up to eight feet by forty feet. SIPs are resource efficient as they use less wood than conventional framing (about 25 per cent less); can structurally cover large spans, requiring less supplementary framing. Use of SIPs eliminate the need for headers over small openings; provide the ability to nail anywhere; create less scrap and waste; lessen vulnerability to unfavourable weather and other job-site hazards, can reduce delays, and often can produce significant savings in material and labour costs. Limitations include the more complex approaches to plumbing and electrical systems, although this can be minimized by designers by incorporating much of the plumbing and electrical work on interior (non-panel) walls. Most stressed skin panels require one-half inch interior gypsum drywall. If become wet, stressed skin panels take a long time to dry out and may harbour mold growth. Larger stressed-skin panels used in floors and roofs, may require cranes or other machinery for handling because of their weight. Although not without some environmental impact, overall, stressed skin panels are judged to be a resource-efficient building technology with significant energy-efficiency benefits and distinct advantages over stick framing. 3 photos.

Mechanical and thermal stresses in a functionally graded rotating disk with variable thickness due to radially symmetry loads

International Nuclear Information System (INIS)

Bayat, Mehdi; Saleem, M.; Sahari, B.B.; Hamouda, A.M.S.; Mahdi, E.

2009-01-01

Rotating disks have many applications in the aerospace industry such as gas turbines and gears. These disks normally work under thermo mechanical loads. Minimizing the weight of such components can help reduce the overall payload in aerospace industry. For this purpose, a rotating functionally graded (FG) disk with variable thickness under a steady temperature field is considered in this paper. Thermo elastic solutions and the weight of the disk are related to the material grading index and the geometry of the disk. It is found that a disk with parabolic or hyperbolic convergent thickness profile has smaller stresses and displacements compared to a uniform thickness disk. Maximum radial stress due to centrifugal load in the solid disk with parabolic thickness profile may not be at the center unlike uniform thickness disk. Functionally graded disk with variable thickness has smaller stresses due to thermal load compared to those with uniform thickness. It is seen that for a given value of grading index, the FG disk having concave thickness profile is the lightest in weight whereas the FG disk with uniform thickness profile is the heaviest. Also for any given thickness profile, the weight of the FG disk lies in between the weights of the all-metal and the all-ceramic disks.

Size-dependent electro-magneto-elastic bending analyses of the shear-deformable axisymmetric functionally graded circular nanoplates

Science.gov (United States)

Arefi, Mohammad; Zenkour, Ashraf M.

2017-10-01

This paper develops nonlocal elasticity equations and magneto-electro-elastic relations to size-dependent electro-magneto-elastic bending analyses of the functionally graded axisymmetric circular nanoplates based on the first-order shear deformation theory. All material properties are graded along the thickness direction based on exponential varying. It is assumed that a circular nanoplate is made from piezo-magnetic materials. The energy method and Ritz approach is employed for the derivation of governing equations of electro-magneto-elastic bending and the solution of the problem, respectively. The nanoplate is subjected to applied electric and magnetic potentials at top and transverse loads while it is rested on Pasternak's foundation. Some important numerical results are presented in various figures to show the influence of applied electric and magnetic potentials, small scale parameter and inhomogeneous index of an exponentially graded nanoplate.

Sound transmission through triple-panel structures lined with poroelastic materials

Science.gov (United States)

Liu, Yu

2015-03-01

In this paper, previous theories on the prediction of sound transmission loss for a double-panel structure lined with poroelastic materials are extended to address the problem of a triple-panel structure. Six typical configurations are considered for a triple-panel structure based on the method of coupling the porous layers to the facing panels which determines critically the sound insulation performance of the system. The transfer matrix method is employed to solve the system by applying appropriate types of boundary conditions for these configurations. The transmission loss of the triple-panel structures in a diffuse sound field is calculated as a function of frequency and compared with that of corresponding double-panel structures. Generally, the triple-panel structure with poroelastic linings has superior acoustic performance to the double-panel counterpart, remarkably in the mid-high frequency range and possibly at low frequencies, by selecting appropriate configurations in which those with two air gaps in the structure exhibit the best overall performance over the entire frequency range. The poroelastic lining significantly lowers the cut-on frequency above which the triple-panel structure exhibits noticeably higher transmission loss. Compared with a double-panel structure, the wider range of system parameters for a triple-panel structure due to the additional partition provides more design space for tuning the sound insulation performance. Despite the increased structural complexity, the triple-panel structure lined with poroelastic materials has the obvious advantages in sound transmission loss while without the penalties in weight and volume, and is hence a promising replacement for the widely used double-panel sandwich structure.

77 FR 2340 - Occupational Information Development Advisory Panel

Science.gov (United States)

2012-01-17

... economics, sampling, data collection and analyses; (b) disability evaluation, vocational rehabilitation... rehabilitation medicine, psychiatry, or psychology; and (d) disability claimant advocacy. The Panel will function...

Prediction of sound transmission loss through multilayered panels by using Gaussian distribution of directional incident energy

Science.gov (United States)

Kang; Ih; Kim; Kim

2000-03-01

In this study, a new prediction method is suggested for sound transmission loss (STL) of multilayered panels of infinite extent. Conventional methods such as random or field incidence approach often given significant discrepancies in predicting STL of multilayered panels when compared with the experiments. In this paper, appropriate directional distributions of incident energy to predict the STL of multilayered panels are proposed. In order to find a weighting function to represent the directional distribution of incident energy on the wall in a reverberation chamber, numerical simulations by using a ray-tracing technique are carried out. Simulation results reveal that the directional distribution can be approximately expressed by the Gaussian distribution function in terms of the angle of incidence. The Gaussian function is applied to predict the STL of various multilayered panel configurations as well as single panels. The compared results between the measurement and the prediction show good agreements, which validate the proposed Gaussian function approach.

Functional grading of mineral and collagen in the attachment of tendon to bone.

Science.gov (United States)

Genin, Guy M; Kent, Alistair; Birman, Victor; Wopenka, Brigitte; Pasteris, Jill D; Marquez, Pablo J; Thomopoulos, Stavros

2009-08-19

Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.

Contact statuses between functionally graded brake disk and pure pad disk

International Nuclear Information System (INIS)

Shahzamanian, M.M.; Sahari, B.B.; Bayat, M.; Mustapha, F.; Ismarrubie, Z.N.; Shahrjerdi, A.

2009-01-01

Full text: The contact statuses between functionally graded (FG) brake disks and pure pad disk are investigated by using finite element method (FEM). Two types of variation is considered for FG brake disk, the variation of materials are considered change in radial and thickness direction of disk. The material properties of these two types of FG brake disks are assumed to be represented by power-law distributions in the radius and thickness direction. The results are obtained and then compared. For the radial FG brake disk, the inner and outer surfaces are considered metal and ceramic respectively, and friction coefficient between metal surface and ceramic surface of FG brake dick with pad are considered 1.4 and 0.75 respectively. For the thickness FG brake disk the contact surface with pure pad brake disk is ceramic and the free surface is metal and friction coefficient between ceramic (contact) surface and pure pad brake disk is considered 0.75. In both types of FG brake disks the Coulomb contact friction is applied. Mechanical response of FG brake disks are compared and verified with the known results in the literatures. Three types of contact statuses are introduced as Sticking, Contact and Near Contact. The contact status between pad and disk for different values for pad thickness, grading index,n , and percentage of friction coefficient (λ) is shown. It can be seen that for all values of percentage of friction coefficient,λ , and grading indices, n, by increasing the thickness of pad cause the contact status changes from sticking to contact and then to near contact. (author)

Multi-objective optimal design of sandwich panels using a genetic algorithm

Science.gov (United States)

Xu, Xiaomei; Jiang, Yiping; Pueh Lee, Heow

2017-10-01

In this study, an optimization problem concerning sandwich panels is investigated by simultaneously considering the two objectives of minimizing the panel mass and maximizing the sound insulation performance. First of all, the acoustic model of sandwich panels is discussed, which provides a foundation to model the acoustic objective function. Then the optimization problem is formulated as a bi-objective programming model, and a solution algorithm based on the non-dominated sorting genetic algorithm II (NSGA-II) is provided to solve the proposed model. Finally, taking an example of a sandwich panel that is expected to be used as an automotive roof panel, numerical experiments are carried out to verify the effectiveness of the proposed model and solution algorithm. Numerical results demonstrate in detail how the core material, geometric constraints and mechanical constraints impact the optimal designs of sandwich panels.

Comprehensive metabolic panel

Science.gov (United States)

Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20 ... Chernecky CC, Berger BJ. Comprehensive metabolic panel (CMP) - blood. In: ... Tests and Diagnostic Procedures . 6th ed. St Louis, MO: ...

A New Class of Functionally Graded Cearamic-Metal Composites for Next Generation Very High Temperature Reactors

International Nuclear Information System (INIS)

Jain, Mohit; Skandan, Ganesh; Khose, Gordon E.; Maro, Judith

2008-01-01

Generation IV Very High Temperature power generating nuclear reactors will operate at temperatures greater than 900 C. At these temperatures, the components operating in these reactors need to be fabricated from materials with excellent thermo-mechanical properties. Conventional pure or composite materials have fallen short in delivering the desired performance. New materials, or conventional materials with new microstructures, and associated processing technologies are needed to meet these materials challenges. Using the concept of functionally graded materials, we have fabricated a composite material which has taken advantages of the mechanical and thermal properties of ceramic and metals. Functionally-graded composite samples with various microstructures were fabricated. It was demonstrated that the composition and spatial variation in the composition of the composite can be controlled. Some of the samples were tested for irradiation resistance to neutrons. The samples did not degrade during initial neutron irradiation testing.

"A New Class od Functionally Graded Cearamic-Metal Composites for Next Generation Very High Temperature Reactors"

Energy Technology Data Exchange (ETDEWEB)

Dr. Mohit Jain; Dr. Ganesh Skandan; Dr. Gordon E. Khose; Mrs. Judith Maro, Nuclear Reactor Laboratory, MIT

2008-05-01

Generation IV Very High Temperature power generating nuclear reactors will operate at temperatures greater than 900 oC. At these temperatures, the components operating in these reactors need to be fabricated from materials with excellent thermo-mechanical properties. Conventional pure or composite materials have fallen short in delivering the desired performance. New materials, or conventional materials with new microstructures, and associated processing technologies are needed to meet these materials challenges. Using the concept of functionally graded materials, we have fabricated a composite material which has taken advantages of the mechanical and thermal properties of ceramic and metals. Functionally-graded composite samples with various microstructures were fabricated. It was demonstrated that the composition and spatial variation in the composition of the composite can be controlled. Some of the samples were tested for irradiation resistance to neutrons. The samples did not degrade during initial neutron irradiation testing.

Noise Reduction in Double‿Panel Structures by Cavity and Panel Resonance Control

NARCIS (Netherlands)

Ho, J.; Berkhoff, Arthur P.

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‿panel structure. The double‿panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective

Noise reduction in double-panel structures by cavity and panel resonance control

NARCIS (Netherlands)

Ho, J.-H.; Berkhoff, A.P

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‐panel structure. The double‐panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective

Eighth Grade In-Service Teachers' Knowledge of Proportional Reasoning and Functions: A Secondary Data Analysis

Science.gov (United States)

Masters, Jessica

2012-01-01

A secondary data analysis was conducted using a large dataset from a study related to online professional development for eighth grade teachers of mathematics. Using this data, the paper provides a snapshot of the current state of teachers' knowledge related to proportional reasoning and functions. The paper also considers how teachers' knowledge…

Improving the efficiency of photovoltaic (PV) panels by oil coating

International Nuclear Information System (INIS)

Abd-Elhady, M.S.; Fouad, M.M.; Khalil, T.

2016-01-01

Highlights: • It is possible to improve the efficiency of PV panels by increasing the amount of light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the amount of sun light transmitted to the panel. • Coating PV panels by a fine layer of Labovac oil increases the power output of the panel. • Coating PV panels with a layer of Labovac oil has to be applied in cold countries and not in hot regions. - Abstract: The objective of this research is to develop a new technique for improving the efficiency of Photovoltaic (PV) panels. This technique is done by coating the front surface of the PV panel by a fine layer of oil in order to increase the amount of light transmitted to the panel, and consequently its efficiency. Different types of oils are examined, including both mineral oils and natural oils. In case of mineral oils; vacuum pump oil (Labovac oil), engine oil (Mobil oil) and brake oil (Abro oil) are examined, while in case of natural oils; olive and sunflower oils are examined. An experimental setup has been developed to examine the performance of the PV panels as a function of oil coatings. The experimental setup consists of an artificial sun, the PV panel under investigation, a cooling system and a measuring system to measure the performance of the panel. It has been found that coating the PV panel with a fine layer of Labovac oil, ∼1 mm thick, improves the efficiency of the PV panel by more than 20%, and this is due to the high transmissivity of the Labovac oil compared to other oils. However, the Labovac oil has a drawback which is overheating of the panel due to its high transmissivity. Coating of PV panels with a fine layer of Labovac oil should be done only in cold regions, in order to avoid the heating effect that can decrease the power output of PV panels.

Replacement of the glove box panel in nuclear fuel reprocessing facility

International Nuclear Information System (INIS)

Yamamoto, Masahiko; Shirouzu, Hidetomo; Mori, Eito; Surugaya, Naoki

2016-05-01

The panels for visual confirmation of glove box installed at Operation Testing Laboratory in Tokai Reprocessing Plant have been deteriorated and transparencies have been decreased due to the long-term use. Therefore, the glove box panels have been replaced from the view point of preventive maintenance. In the new regulation formulated since the accident at Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station, it is demanded that the glove box consists of incombustible or noncombustible materials. In this replacement, the new panels have been manufactured with the polycarbonate which satisfied the UL94 V-0 incombustible class. The glove box has been in service for 40 years and its inside is contaminated with radioactive materials. Thus, the contaminations have been investigated and decontaminated before the replacement work. Then, operator's exposure and radiation protection equipment have been estimated. Also, it is necessary to replace the panels with maintaining the glove box's enclosure function. The replacement has been conducted in closed space covering the opening parts with vinyl sheets. The enclosure function has been verified by the inspection of the new panels and glove box. (author)

Integration of a functionally graded W/Cu transition for divertor components of fusion facilities

International Nuclear Information System (INIS)

Pintsuk, G.

2004-01-01

One of the most difficult topics in the design and development of future fusion devices, e.g. ITER (Latin for ''the way'') is the field of plasma facing components for the divertor. In steady-state mode these will be exposed to heat fluxes up to 20 MW/m 2 . The favored design-option is a component made out of tungsten and copper-alloys. Since these materials differ in their thermal expansion coefficient and their elastic modulus a temperature gradient within the component, caused by thermal loads, results in stresses at the interface. An alternative design-option for divertor-components deals with the insertion of a functionally graded material (FGM) between tungsten and copper. This establishes a continuous change of material properties and therefore minimize the stresses and optimize the thermal behavior of the component. Low pressure plasma-spraying and direct laser-sintering are introduced as possible production-methods of graded W/Cu-composites. Based on preliminary investigations both are used for fabricating W/Cu-composite materials with different mixing ratios. Thermo-mechanical and thermo-physical material properties will be determined on these composites and extrapolated to all mixing ratios. For laser-sintering these are limited to Cu-contents of ∝20 to 100 Vol%. Therefore the plasma-spraying process is favored. In finite-element-analyses the graded material and its material properties will be implemented into a 2-D simulation-model of a divertor component. The composition and the design of the graded W/Cu-composite will be optimized. Best results are obtained by high contents of tungsten within the graded layer, which are still improved by a macro-brush design with dimensions of 4.5 x 4.5 mm 2 . This results in a transfer of critical stresses from the mechanical bonded interface between the plasma facing and the graded material to the diffusion bonded interface between the graded material and copper. The joining of tungsten, a plasma-sprayed graded W

PERBANDINGAN UNJUK KERJA ANTARA PANEL SEL SURYA BERPENJEJAK DENGAN PANEL SEL SURYA DIAM

Directory of Open Access Journals (Sweden)

Syafaruddin Ch

2010-07-01

Full Text Available The ability to produce electrical energy at Solar Power Plant  is highly dependent on the magnitude and duration of sun exposure on the solar cell panels. The movement of the sun from east to west that periodicity in every day is a problem at  the  optimization generation of electricity at  Solar Power Plant   if using solar panel that motionless. This is because the solar cell panel can not catch the maximum sun exposure. To solve the above problem then designed a solar cell panel  tracker  capable of follo-wing the movements of the sun. Then conducted a test to see the performance of solar cell pa-nel  tracker  and compare it with the performance of solar cell panel was motionless. The testing doing along 6 days, with way to irradiate the panel of solar cells  tracker  and panels of solar cell motionless with sun exposure  along a  full day. Then the electric current generated each panel were recorded. The comparison of current then generating comparison of electric power delivery. The result show that the solar cell panel  tracker  produce the average current is 2.19 A whereas solar-cell panel still 1.97 A.  This result   indicate that average power for solar cell panel  tracker  39.41 W while for solar cell panel that motionless is  35.46 W. These results indicate that the performance of solar cell panel  tracker  better than  solar cell panel motionless.

Noise Reduction in Double‿Panel Structures by Cavity and Panel Resonance Control

OpenAIRE

Ho, J.; Berkhoff, Arthur P.

2011-01-01

This paper presents an investigation of the cavity and the panel resonance control in a double‿panel structure. The double‿panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its light weight and effective transmission‿loss at high frequency. However, the resonance of the cavity and the poor transmission‿loss at low frequency limit its noise control performance. Applying active control forces on the panels or utili...

GlyEFSA NDA Panel (EFSA Panel on Dietetic Product s, Nutrition and Allergies), 20 13 . Scientific Opinion on the substantiation of a health claim related to glycaemic carbohydrates and recovery of normal muscle function (contraction) after stren uous exercise pursuant to Article 13(5) of Regulation

DEFF Research Database (Denmark)

Tetens, Inge

Following an application from Aptonia, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of France, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientific...... substantiation of a health claim related to glycaemic carbohydrates and recovery of normal muscle function (contraction) after strenuous exercise. The food constituent, glycaemic carbohydrates, which is the subject of the health claim, is sufficiently characterised in relation to the claimed effect. Recovery...... to the recovery of normal skeletal muscle function (contraction), the Panel concludes that a cause and effect relationship has been established between the consumption of glycaemic carbohydrates and recovery of normal muscle function (contraction) after strenuous exercise....

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael

2010-07-25

The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, so-called panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects.

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael

2010-07-26

The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects. © 2010 ACM.

Microstructure and kinetics of a functionally graded NiTi-TiC x composite produced by combustion synthesis

International Nuclear Information System (INIS)

Burkes, Douglas E.; Moore, John J.

2007-01-01

Production of a NiTi-TiC x functionally graded material (FGM) composite is possible through use of a combustion synthesis (CS) reaction employing the propagating mode (SHS). The NiTi-TiC x FGM combines the well-known and understood superelastic and shape memory capabilities of NiTi with the high hardness, wear and corrosion resistance of TiC x . The material layers were observed as functionally graded both in composition and porosity with distinct interfaces, while still maintaining good material interaction and bonding. XRD of the FGM composite revealed the presence of TiC x with equi-atomic NiTi and minor NiTi 2 and NiTi 3 phases. The TiC x particle size decreased with increasing NiTi content. Microindentation performed across the length of the FGM revealed a decrease in hardness as the NiTi content increased

Optimization of a functionally graded circular plate with inner rigid thin obstacles. I. Continuous problems

Czech Academy of Sciences Publication Activity Database

Hlaváček, Ivan; Lovíšek, J.

2011-01-01

Roč. 91, č. 9 (2011), s. 711-723 ISSN 0044-2267 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional research plan: CEZ:AV0Z10190503 Keywords : functionally graded plate * optimal design Subject RIV: BA - General Mathematics Impact factor: 0.863, year: 2011 http://onlinelibrary.wiley.com/doi/10.1002/zamm.201000119/abstract

Panel 5: Microbiology and Immunology Panel

Science.gov (United States)

Murphy, Timothy F.; Chonmaitree, Tasnee; Barenkamp, Stephen; Kyd, Jennelle; Nokso-Koivisto, Johanna; Patel, Janak A.; Heikkinen, Terho; Yamanaka, Noboru; Ogra, Pearay; Swords, W. Edward; Sih, Tania; Pettigrew, Melinda M.

2014-01-01

Objective The objective is to perform a comprehensive review of the literature from January 2007 through June 2011 on the virology, bacteriology, and immunology related to otitis media. Data Sources PubMed database of the National Library of Medicine. Review Methods Three subpanels with co-chairs comprising experts in the virology, bacteriology, and immunology of otitis media were formed. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a second draft was created. The entire panel met at the 10th International Symposium on Recent Advances in Otitis Media in June 2011 and discussed the review and refined the content further. A final draft was created, circulated, and approved by the panel. Conclusion Excellent progress has been made in the past 4 years in advancing an understanding of the microbiology and immunology of otitis media. Advances include laboratory-based basic studies, cell-based assays, work in animal models, and clinical studies. Implications for Practice The advances of the past 4 years formed the basis of a series of short-term and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media. PMID:23536533

Eighth Grade Algebra Course Placement and Student Motivation for Mathematics

Science.gov (United States)

Simzar, Rahila M.; Domina, Thurston; Tran, Cathy

2016-01-01

This study uses student panel data to examine the association between Algebra placement and student motivation for mathematics. Changes in achievement goals, expectancy, and task value for students in eighth grade Algebra are compared with those of peers placed in lower-level mathematics courses (N = 3,306). In our sample, students placed in Algebra reported an increase in performance-avoidance goals as well as decreases in academic self-efficacy and task value. These relations were attenuated for students who had high mathematics achievement prior to Algebra placement. Whereas all students reported an overall decline in performance-approach goals over the course of eighth grade, previously high-achieving students reported an increase in these goals. Lastly, previously high-achieving students reported an increase in mastery goals. These findings suggest that while previously high-achieving students may benefit motivationally from eighth grade Algebra placement, placing previously average- and low-performing students in Algebra can potentially undermine their motivation for mathematics. PMID:26942210

Eighth Grade Algebra Course Placement and Student Motivation for Mathematics.

Science.gov (United States)

Simzar, Rahila M; Domina, Thurston; Tran, Cathy

2016-01-01

This study uses student panel data to examine the association between Algebra placement and student motivation for mathematics. Changes in achievement goals, expectancy, and task value for students in eighth grade Algebra are compared with those of peers placed in lower-level mathematics courses (N = 3,306). In our sample, students placed in Algebra reported an increase in performance-avoidance goals as well as decreases in academic self-efficacy and task value. These relations were attenuated for students who had high mathematics achievement prior to Algebra placement. Whereas all students reported an overall decline in performance-approach goals over the course of eighth grade, previously high-achieving students reported an increase in these goals. Lastly, previously high-achieving students reported an increase in mastery goals. These findings suggest that while previously high-achieving students may benefit motivationally from eighth grade Algebra placement, placing previously average- and low-performing students in Algebra can potentially undermine their motivation for mathematics.

SEM and EBSD characterization of bi-layered functionally graded hard metal composites; REM- und EBSD-Charakterisierung von zweischichtigen, funktionell abgestuften Metallverbundwerkstoffen

Energy Technology Data Exchange (ETDEWEB)

Prat, Orlando; Sanhueza, Felipe [Univ. de Concepcion (Chile). Dept. de Ingenieria de Materiales; Suarez, Sebastian [Saarland Univ., Saarbruecken (Germany). Chair of Functional Materials; Garcia, Jose [AB Sandvik Coromant R and D, Stockholm (Sweden)

2016-11-15

WC-Co bi-layer functionally graded composites were produced by powder metallurgy techniques. The influence of WC particle size and the grain growth inhibitor on the formation of the functionally graded composite was investigated. SEM images show that all sintered samples present a graded microstructure after sintering, with two side regions of extra-coarse and coarse WC-Co and a clear, dense interface without defects or other phases. EBSD results showed a change of WC particle size depending on the processing and the addition of Mo{sub 2}C. Cobalt binder distribution corresponds to WC particle size. Hardness values correlate to WC particle size and binder content. It is shown that tailored hardness/toughness can be produced by adjusting the WC particle size and binder content on both sides of the bi-layer composite.

Industrial based volume manufacturing of lightweight aluminium alloy panel components with high-strength and complex-shape for car body and chassis structures

Science.gov (United States)

Anyasodor, Gerald; Koroschetz, Christian

2017-09-01

To achieve the high volume manufacture of lightweight passenger cars at economic cost as required in the automotive industry, low density materials and new process route will be needed. While high strength aluminium alloy grades: AA7075 and AA6082 may provide the alternative material solution, hot stamping process used for high-strength and ultrahigh strength steels such as boron steel 22mnb5 can enable the volume manufacture of panel components with high-strength and complex-shape for car body and chassis structures. These aluminium alloy grades can be used to manufacture panel components with possible yield strengths ≥ 500 MPa. Due to the differences in material behaviors, hot stamping process of 22mnb5 cannot be directly applied to high strength aluminium alloy grades. Despite recorded successes in laboratories, researches and niche hot forming processes of high strength aluminium alloy grades, not much have been achieved for adequate and efficient volume manufacturing system applicable in the automotive industry. Due to lack of such system and based on expert knowledge in hot stamping production-line, AP&T presents in this paper a hot stamping processing route for high strength aluminium alloys been suitable for production-line development and volume manufacturing.

Transmission loss optimization in acoustic sandwich panels

Science.gov (United States)

Makris, S. E.; Dym, C. L.; MacGregor Smith, J.

1986-06-01

Considering the sound transmission loss (TL) of a sandwich panel as the single objective, different optimization techniques are examined and a sophisticated computer program is used to find the optimum TL. Also, for one of the possible case studies such as core optimization, closed-form expressions are given between TL and the core-design variables for different sets of skins. The significance of these functional relationships lies in the fact that the panel designer can bypass the necessity of using a sophisticated software package in order to assess explicitly the dependence of the TL on core thickness and density.

Layout of 'hard' and 'soft' control panels

International Nuclear Information System (INIS)

Schulz, K.A.

1984-01-01

Large control panels, containing hundreds of indicators and controls, have long been used in process plants. The general arrangement of instruments on the panel should reflect ergonomic principles to help operators to quickly and accurately locate, identify and select controls and displays as they monitor and supervise plant systems and processes. For the multiplexed systems now displacing dedicated components, there is a corresponding set of design problems involving display-page formats and the design of display ensembles. A list of alternative organizing principles is presented, with particular emphasis on those based on plant function. Methodologies for selecting and applying the principles are discussed

The irradiance and temperature dependent mathematical model for estimation of photovoltaic panel performances

International Nuclear Information System (INIS)

Barukčić, M.; Ćorluka, V.; Miklošević, K.

2015-01-01

Highlights: • The temperature and irradiance dependent model for the I–V curve estimation is presented. • The purely mathematical model based on the analysis of the I–V curve shape is presented. • The model includes the Gompertz function with temperature and irradiance dependent parameters. • The input data are extracted from the data sheet I–V curves. - Abstract: The temperature and irradiance dependent mathematical model for photovoltaic panel performances estimation is proposed in the paper. The base of the model is the mathematical function of the photovoltaic panel current–voltage curve. The model of the current–voltage curve is based on the sigmoid function with temperature and irradiance dependent parameters. The temperature and irradiance dependencies of the parameters are proposed in the form of analytic functions. The constant parameters are involved in the analytical functions. The constant parameters need to be estimated to get the temperature and irradiance dependent current–voltage curve. The mathematical model contains 12 constant parameters and they are estimated by using the evolutionary algorithm. The optimization problem is defined for this purpose. The optimization problem objective function is based on estimated and extracted (measured) current and voltage values. The current and voltage values are extracted from current–voltage curves given in datasheet of the photovoltaic panels. The new procedure for estimation of open circuit voltage value at any temperature and irradiance is proposed in the model. The performance of the proposed mathematical model is presented for three different photovoltaic panel technologies. The simulation results indicate that the proposed mathematical model is acceptable for estimation of temperature and irradiance dependent current–voltage curve and photovoltaic panel performances within temperature and irradiance ranges

Functionally graded material of 304L stainless steel and inconel 625 fabricated by directed energy deposition: Characterization and thermodynamic modeling

International Nuclear Information System (INIS)

Carroll, Beth E.; Otis, Richard A.; Borgonia, John Paul; Suh, Jong-ook; Dillon, R. Peter; Shapiro, Andrew A.; Hofmann, Douglas C.; Liu, Zi-Kui; Beese, Allison M.

2016-01-01

Many engineering applications, particularly in extreme environments, require components with properties that vary with location in the part. Functionally graded materials (FGMs), which possess gradients in properties such as hardness or density, are a potential solution to address these requirements. The laser-based additive manufacturing process of directed energy deposition (DED) can be used to fabricate metallic parts with a gradient in composition by adjusting the volume fraction of metallic powders delivered to the melt pool as a function of position. As this is a fusion process, secondary phases may develop in the gradient zone during solidification that can result in undesirable properties in the part. This work describes experimental and thermodynamic studies of a component built from 304L stainless steel incrementally graded to Inconel 625. The microstructure, chemistry, phase composition, and microhardness as a function of position were characterized by microscopy, energy dispersive spectroscopy, X-ray diffraction, and microindentation. Particles of secondary phases were found in small amounts within cracks in the gradient zone. These were ascertained to consist of transition metal carbides by experimental results and thermodynamic calculations. The study provides a combined experimental and thermodynamic computational modeling approach toward the fabrication and evaluation of a functionally graded material made by DED additive manufacturing.

Exploring the role and function of trial steering committees: results of an expert panel meeting.

Science.gov (United States)

Harman, Nicola L; Conroy, Elizabeth J; Lewis, Steff C; Murray, Gordon; Norrie, John; Sydes, Matt R; Lane, J Athene; Altman, Douglas G; Baigent, Colin; Bliss, Judith M; Campbell, Marion K; Elbourne, Diana; Evans, Stephen; Sandercock, Peter; Gamble, Carrol

2015-12-30

The independent oversight of clinical trials, which is recommended by the Medical Research Council (MRC) Guidelines for Good Clinical Practice, is typically provided by an independent advisory Data Monitoring Committee (DMC) and an independent executive committee, to whom the DMC makes recommendations. The detailed roles and function of this executive committee, known as the Trial Steering Committee (TSC), have not previously been studied or reviewed since those originally proposed by the MRC in 1998. An expert panel (n = 7) was convened comprising statisticians, clinicians and trial methodologists with prior TSC experience. Twelve questions about the role and responsibilities of the TSC were discussed by the panel at two full-day meetings. Each meeting was transcribed in full and the discussions were summarised. The expert panel reached agreement on the role of the TSC, to which it was accountable, the membership, the definition of independence, and the experience and training needed. The management of ethical issues, difficult/complex situations and issues the TSC should not ask the DMC to make recommendations on were more difficult to discuss without specific examples, but support existed for further work to help share issues and to provide appropriate training for TSC members. Additional topics discussed, which had not been identified by previous work relating to the DMCs but were pertinent to the role of the TSC, included the following: review of data sharing requests, indemnity, lifespan of the TSC, general TSC administration, and the roles of both the Funder and the Sponsor. This paper presents recommendations that will contribute to the revision and update of the MRC TSC terms of reference. Uncertainty remains in some areas due to the absence of real-life examples; future guidance on these issues would benefit from a repository of case studies. Notably, the role of a patient and public involvement (PPI) contributor was not discussed, and further work is

Comparisons between various cavity and panel noise reduction control in double-panel structures

NARCIS (Netherlands)

Ho, J.H.; Kalverboer, J.; Berkhoff, A.P.

2012-01-01

This paper presents comparisons between various panel and cavity resonance control methods to reduce the transmitted sound in a double-panel structure. The double-panel, which consists of two panels with air in the gap, has the advantages of low weight and effective transmission-loss at high

Improvement in cognitive function after surgery for low-grade glioma.

Science.gov (United States)

Barzilai, Ori; Ben Moshe, Shlomit; Sitt, Razi; Sela, Gal; Shofty, Ben; Ram, Zvi

2018-03-23

OBJECTIVE Cognition is a key component in health-related quality of life (HRQoL) and is currently incorporated as a major parameter of outcome assessment in patients treated for brain tumors. The effect of surgery on cognition and HRQoL remains debatable. The authors investigated the impact of resection of low-grade gliomas (LGGs) on cognition and the correlation with various histopathological markers. METHODS A retrospective analysis of patients with LGG who underwent craniotomy for tumor resection at a single institution between 2010 and 2014 was conducted. Of 192 who underwent resective surgery for LGG during this period, 49 had complete pre- and postoperative neurocognitive evaluations and were included in the analysis. These patients completed a full battery of neurocognitive tests (memory, language, attention and working memory, visuomotor organization, and executive functions) pre- and postoperatively. Tumor and surgical characteristics were analyzed, including volumetric measurements and histopathological markers (IDH, p53, GFAP). RESULTS Postoperatively, significant improvement was found in memory and executive functions. A subgroup analysis of patients with dominant-side tumors, most of whom underwent intraoperative awake mapping, revealed significant improvement in the same domains. Patients whose tumors were on the nondominant side displayed significant improvement only in memory functions. Positive staining for p53 testing was associated with improved language function and greater extent of resection in dominant-side tumors. GFAP positivity was associated with improved memory in patients whose tumors were on the nondominant side. No correlation was found between cognitive outcome and preoperative tumor volume, residual volume, extent of resection, or IDH1 status. CONCLUSIONS Resection of LGG significantly improves memory and executive function and thus is likely to improve functional outcome in addition to providing oncological benefit. GFAP and pP53

Solar reflection panels

Science.gov (United States)

Diver, Jr., Richard B.; Grossman, James W [Albuquerque, NM; Reshetnik, Michael [Boulder, CO

2006-07-18

A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

The Ottawa Panel guidelines on programmes involving therapeutic exercise for the management of hand osteoarthritis.

Science.gov (United States)

Brosseau, Lucie; Thevenot, Odette; MacKiddie, Olivia; Taki, Jade; Wells, George A; Guitard, Paulette; Léonard, Guillaume; Paquet, Nicole; Aydin, Sibel Z; Toupin-April, Karine; Cavallo, Sabrina; Moe, Rikke Helene; Shaikh, Kamran; Gifford, Wendy; Loew, Laurianne; De Angelis, Gino; Shallwani, Shirin Mehdi; Aburub, Ala' S; Mizusaki Imoto, Aline; Rahman, Prinon; Álvarez Gallardo, Inmaculada C; Cosic, Milkana Borges; Østerås, Nina; Lue, Sabrina; Hamasaki, Tokiko; Gaudreault, Nathaly; Towheed, Tanveer E; Koppikar, Sahil; Kjeken, Ingvild; Mahendira, Dharini; Kenny, Glen P; Paterson, Gail; Westby, Marie; Laferrière, Lucie; Longchamp, Guy

2018-06-01

To identify programmes involving therapeutic exercise that are effective for the management of hand osteoarthritis and to provide stakeholders with updated, moderate to high-quality recommendations supporting exercises for hand osteoarthritis. A systematic search and adapted selection criteria included comparable trials with exercise programmes for managing hand osteoarthritis. Based on the evaluated evidence, a panel of experts reached consensus through a Delphi approach endorsing the recommendations. A hierarchical alphabetical grading system (A, B, C+, C, C-, D-, D, D+, E, F) was based on clinical importance (≥15%) and statistical significance ( P 12 weeks) trials for physical function and pinch strength. Despite that many programmes involving exercise with positive recommendations for clinical outcomes are available to healthcare professionals and hand osteoarthritis patients that aid in the management of hand osteoarthritis, there is a need for further research to isolate the specific effect of exercise components.

Strategy-focused writing instruction: just observing and reflecting on a model benefits 6th grade students

NARCIS (Netherlands)

Fidalgo, R.; Torrance, M.; Rijlaarsdam, G.; van den Bergh, H.; Álvarez, M.L.

2015-01-01

Three groups of typically-developing 6th grade students (total N = 62) each completed strategy-focused writing training. Using a combined lagged-group and cross-panel design we assessed the effectiveness of a sequence of four different instructional components: observation and group reflection on a

Proficiency testing for sensory profile panels : measuring panel performance

NARCIS (Netherlands)

Mcewan, J.A.; Hunter, E.A.; Gemert, L.J. van; Lea, P.

2002-01-01

Proficiency testing in sensory analysis is an important step towards demonstrating that results from one sensory panel are consistent with the results of other sensory panels. The uniqueness of sensory analysis poses some specific problems for measuring the proficiency of the human instrument

Ottawa Panel Evidence-Based Clinical Practice Guidelines for Foot Care in the Management of Juvenile Idiopathic Arthritis.

Science.gov (United States)

Brosseau, Lucie; Toupin-April, Karine; Wells, George; Smith, Christine A; Pugh, Arlanna G; Stinson, Jennifer N; Duffy, Ciarán M; Gifford, Wendy; Moher, David; Sherrington, Catherine; Cavallo, Sabrina; De Angelis, Gino; Loew, Laurianne; Rahman, Prinon; Marcotte, Rachel; Taki, Jade; Bisaillon, Jacinthe; King, Judy; Coda, Andrea; Hendry, Gordon J; Gauvreau, Julie; Hayles, Martin; Hayles, Kay; Feldman, Brian; Kenny, Glen P; Li, Jing Xian; Briggs, Andrew M; Martini, Rose; Feldman, Debbie Ehrmann; Maltais, Désirée B; Tupper, Susan; Bigford, Sarah; Bisch, Marg

2016-07-01

To create evidence-based guidelines evaluating foot care interventions for the management of juvenile idiopathic arthritis (JIA). An electronic literature search of the following databases from database inception to May 2015 was conducted: MEDLINE (Ovid), EMBASE (Ovid), Cochrane CENTRAL, and clinicaltrials.gov. The Ottawa Panel selection criteria targeted studies that assessed foot care or foot orthotic interventions for the management of JIA in those aged 0 to ≤18 years. The Physiotherapy Evidence Database scale was used to evaluate study quality, of which only high-quality studies were included (score, ≥5). A total of 362 records were screened, resulting in 3 full-text articles and 1 additional citation containing supplementary information included for the analysis. Two reviewers independently extracted study data (intervention, comparator, outcome, time period, study design) from the included studies by using standardized data extraction forms. Directed by Cochrane Collaboration methodology, the statistical analysis produced figures and graphs representing the strength of intervention outcomes and their corresponding grades (A, B, C+, C, C-, D+, D, D-). Clinical significance was achieved when an improvement of ≥30% between the intervention and control groups was present, whereas P>.05 indicated statistical significance. An expert panel Delphi consensus (≥80%) was required for the endorsement of recommendations. All included studies were of high quality and analyzed the effects of multidisciplinary foot care, customized foot orthotics, and shoe inserts for the management of JIA. Custom-made foot orthotics and prefabricated shoe inserts displayed the greatest improvement in pain intensity, activity limitation, foot pain, and disability reduction (grades A, C+). The use of customized foot orthotics and prefabricated shoe inserts seems to be a good choice for managing foot pain and function in JIA. Copyright © 2016 American Congress of Rehabilitation

Large thermal protection system panel

Science.gov (United States)

Weinberg, David J. (Inventor); Myers, Franklin K. (Inventor); Tran, Tu T. (Inventor)

2003-01-01

A protective panel for a reusable launch vehicle provides enhanced moisture protection, simplified maintenance, and increased temperature resistance. The protective panel includes an outer ceramic matrix composite (CMC) panel, and an insulative bag assembly coupled to the outer CMC panel for isolating the launch vehicle from elevated temperatures and moisture. A standoff attachment system attaches the outer CMC panel and the bag assembly to the primary structure of the launch vehicle. The insulative bag assembly includes a foil bag having a first opening shrink fitted to the outer CMC panel such that the first opening and the outer CMC panel form a water tight seal at temperatures below a desired temperature threshold. Fibrous insulation is contained within the foil bag for protecting the launch vehicle from elevated temperatures. The insulative bag assembly further includes a back panel coupled to a second opening of the foil bag such that the fibrous insulation is encapsulated by the back panel, the foil bag, and the outer CMC panel. The use of a CMC material for the outer panel in conjunction with the insulative bag assembly eliminates the need for waterproofing processes, and ultimately allows for more efficient reentry profiles.

Reflecting variable opening insulating panel

International Nuclear Information System (INIS)

Nungesser, W.T.

1976-01-01

A description is given of a reflecting variable opening insulating panel assembly, comprising a static panel assembly of reflecting insulation sheets forming a cavity along one side of the panel and a movable panel opening out by sliding from the cavity of the static panel, and a locking device for holding the movable panel in a position extending from the cavity of the static panel. This can apply to a nuclear reactor of which the base might require maintenance and periodical checking and for which it is desirable to have available certain processes for the partial dismantling of the insulation [fr

Differential quadrature method of nonlinear bending of functionally graded beam

Science.gov (United States)

Gangnian, Xu; Liansheng, Ma; Wang, Youzhi; Quan, Yuan; Weijie, You

2018-02-01

Using the third-order shear deflection beam theory (TBT), nonlinear bending of functionally graded (FG) beams composed with various amounts of ceramic and metal is analyzed utilizing the differential quadrature method (DQM). The properties of beam material are supposed to accord with the power law index along to thickness. First, according to the principle of stationary potential energy, the partial differential control formulae of the FG beams subjected to a distributed lateral force are derived. To obtain numerical results of the nonlinear bending, non-dimensional boundary conditions and control formulae are dispersed by applying the DQM. To verify the present solution, several examples are analyzed for nonlinear bending of homogeneous beams with various edges. A minute parametric research is in progress about the effect of the law index, transverse shear deformation, distributed lateral force and boundary conditions.

Puncture panel optimization

International Nuclear Information System (INIS)

Glass, R.E.; Longenbaugh, R.S.

1986-01-01

Sandia National Laboratories developed the TRansUranic PACkage Transporter (TRUPACT) to transport defense contact-handled transuranic wastes. The package has been designed to meet the normal and hypothetical accident conditions in 10CFR71 which includes the demonstrated ability to survive a 1-meter drop onto a mild steel pin. The puncture protection is provided by puncture resistant panels. In conjunction with the development of TRUPACT, a series of experiments has been conducted to reduce the weight of the puncture resistant panels. The initial scoping tests resulted in a preliminary design incorporating 30 layers of Kevlar. This design has been shown to meet the regulatory puncture test. To reduce the weight of this panel, subscale tests were conducted on panels utilizing Kevlar yarns with varying mass per unit length (denier) as well as different resins. This paper reviews the testing undertaken in the original panel development and discusses the results obtained from the recent subscale and full-scale optimization tests

Cavity Control and Panel Control Strategies in Double-Panel Structures for Transmitted Noise Reduction

NARCIS (Netherlands)

Ho, J.; Kalverboer, J.; Berkhoff, Arthur P.

2012-01-01

Investigation and comparisons of the cavity control and the panel control in a double-panel structure are presented in this paper. The double-panel structure, which comprises two panels with air in the gap, provides the advantages of low sound-transmission at high frequency, low heat-transmission

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

DEFF Research Database (Denmark)

Zajas, Jan Jakub; Heiselberg, Per

2013-01-01

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

Transglutaminase 2 expression is increased as a function of malignancy grade and negatively regulates cell growth in meningioma.

Directory of Open Access Journals (Sweden)

Yin-Cheng Huang

Full Text Available Most meningiomas are benign, but some clinical-aggressive tumors exhibit brain invasion and cannot be resected without significant complications. To identify molecular markers for these clinically-aggressive meningiomas, we performed microarray analyses on 24 primary cultures from 21 meningiomas and 3 arachnoid membranes. Using this approach, increased transglutaminase 2 (TGM2 expression was observed, which was subsequently validated in an independent set of 82 meningiomas by immunohistochemistry. Importantly, the TGM2 expression level was associated with increasing WHO malignancy grade as well as meningioma recurrence. Inhibition of TGM2 function by siRNA or cystamine induced meningioma cell death, which was associated with reduced AKT phosphorylation and caspase-3 activation. Collectively, these findings suggest that TGM2 expression increases as a function of malignancy grade and tumor recurrence and that inhibition of TGM2 reduces meningioma cell growth.

Panel Resonance Control and Cavity Control in Double-Panel Structures for Active Noise Reduction

NARCIS (Netherlands)

Ho, J.; Berkhoff, Arthur P.

2011-01-01

An analytical and experimental investigation of panel resonance control and cavity control in a double-panel structure is presented in this paper. The double-panel structure, which consists of two panels with air in the gap, is widely adopted in many applications such as aerospace due to its low

Smartphone-based grading of apple quality

Science.gov (United States)

Li, Xianglin; Li, Ting

2018-02-01

Apple quality grading is a critical issue in apple industry which is one economical pillar of many countries. Artificial grading is inefficient and of poor accuracy. Here we proposed to develop a portable, convenient, real-time, and low cost method aimed at grading apple. Color images of the apples were collected with a smartphone and the grade of sampled apple was assessed by a customized smartphone app, which offered the functions translating RGB color values of the apple to color grade and translating the edge of apple image to weight grade. The algorithms are based on modeling with a large number of apple image at different grades. The apple grade data evaluated by the smartphone are in accordance with the actual data. This study demonstrated the potential of smart phone in apple quality grading/online monitoring at gathering and transportation stage for apple industry.

Three-dimensional thermo-elastic analysis of a functionally graded cylindrical shell with piezoelectric layers by differential quadrature method

Energy Technology Data Exchange (ETDEWEB)

Alashti, R. Akbari, E-mail: raalashti@nit.ac.ir [Mechanical Engineering Department, Babol University of Technology, P.O. Box 484, Shariati Avenue, Babol (Iran, Islamic Republic of); Khorsand, M. [Mechanical Engineering Department, Babol University of Technology, P.O. Box 484, Shariati Avenue, Babol (Iran, Islamic Republic of)

2011-05-15

Three-dimensional thermo-elastic analysis of a functionally graded cylindrical shell with piezoelectric layers under the effect of asymmetric thermo-electro-mechanical loads is carried out. Numerical results of displacement, stress and thermal fields are obtained using two versions of the differential quadrature methods, namely polynomial and Fourier quadrature methods. Material properties of the shell are assumed to be graded in the radial direction according to a power law but the Poisson's ratio is assumed to be constant. Shells are considered to be under the effect of the pressure loading in the form of cosine and ring pressure loads, electric potentials and temperature fields. Numerical results for various boundary conditions are obtained and the effects of the thickness of piezoelectric layers, grading index of material properties and the ratio of the thickness to the radius of the shell on these results is presented. - Highlights: > A numerical study of an FGM cylindrical shell with piezoelectric layers is made. > Governing equations are solved by two versions of differential quadrature methods. > The effect of layers thickness, grading index and geometrical ratios is presented.

Three-dimensional thermo-elastic analysis of a functionally graded cylindrical shell with piezoelectric layers by differential quadrature method

International Nuclear Information System (INIS)

Alashti, R. Akbari; Khorsand, M.

2011-01-01

Three-dimensional thermo-elastic analysis of a functionally graded cylindrical shell with piezoelectric layers under the effect of asymmetric thermo-electro-mechanical loads is carried out. Numerical results of displacement, stress and thermal fields are obtained using two versions of the differential quadrature methods, namely polynomial and Fourier quadrature methods. Material properties of the shell are assumed to be graded in the radial direction according to a power law but the Poisson's ratio is assumed to be constant. Shells are considered to be under the effect of the pressure loading in the form of cosine and ring pressure loads, electric potentials and temperature fields. Numerical results for various boundary conditions are obtained and the effects of the thickness of piezoelectric layers, grading index of material properties and the ratio of the thickness to the radius of the shell on these results is presented. - Highlights: → A numerical study of an FGM cylindrical shell with piezoelectric layers is made. → Governing equations are solved by two versions of differential quadrature methods. → The effect of layers thickness, grading index and geometrical ratios is presented.

Size-dependent vibrations of post-buckled functionally graded Mindlin rectangular microplates

Directory of Open Access Journals (Sweden)

R. Ansari

Full Text Available In this paper, the free vibration behavior of post-buckled functionally graded (FG Mindlin rectangular microplates are described based on the modified couple stress theory (MCST. This theory enables the consideration of the size-effect through introducing material length scale parameters. The FG microplates made of a mixture of metal and ceramic are considered whose volume fraction of components is expressed by a power law function. By means of Hamilton's principle, the nonlinear governing equations and associated boundary conditions are derived for FG micro-plates in the postbuckling domain. The governing equations and boundary conditions are then discretized by using the generalized differential quadrature (GDQ method before solving numerically by the pseudo-arclength continuation technique. In the solution procedure, the postbuckling problem of microplates is investigated first. Afterwards, the free vibration of microplates around the buckled configuration is discussed. The effects of dimensionless length scale parameter, material gradient index and aspect ratio on the on the postbuckling path and frequency of FG microplates subject to arbitrary edge supports are thoroughly discussed.

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies) , 2013. Scientific Opinion on the substantiation of a health claim related to Transitech ® and improvement of bowel function which is maintained after cessation of consumption of the food pursuant to Article 13

DEFF Research Database (Denmark)

Tetens, Inge

Following an application from Vivatech, submitted for authorisation of a health claim pursuant to Article 13(5) of Regulation (EC) No 1924/2006 via the Competent Authority of France, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver an opinion on the scientif...... of the food. A cause and effect relationship has not been established between the consumption of Transitech® and improvement of bowel function which is maintained after cessation of consumption of the food. © European Food Safety Authority, 2013...... substantiation of a health claim related to Transitech® and improvement of bowel function which is maintained after cessation of consumption of the food. The food, Transitech®, that is the subject of the health claim is sufficiently characterised. The claimed effect, improvement of bowel function which...... is maintained after cessation of consumption of the food, is a beneficial physiological effect. In weighing the evidence, the Panel considered that the one study that investigated the claimed effect did not show an effect of Transitech® on bowel function which is maintained after cessation of consumption...

Panel data specifications in nonparametric kernel regression

DEFF Research Database (Denmark)

Czekaj, Tomasz Gerard; Henningsen, Arne

parametric panel data estimators to analyse the production technology of Polish crop farms. The results of our nonparametric kernel regressions generally differ from the estimates of the parametric models but they only slightly depend on the choice of the kernel functions. Based on economic reasoning, we...

Analytical and experimental investigation on transmission loss of clamped double panels: implication of boundary effects.

Science.gov (United States)

Xin, F X; Lu, T J

2009-03-01

The air-borne sound insulation performance of a rectangular double-panel partition clamp mounted on an infinite acoustic rigid baffle is investigated both analytically and experimentally and compared with that of a simply supported one. With the clamped (or simply supported) boundary accounted for by using the method of modal function, a double series solution for the sound transmission loss (STL) of the structure is obtained by employing the weighted residual (Galerkin) method. Experimental measurements with Al double-panel partitions having air cavity are subsequently carried out to validate the theoretical model for both types of the boundary condition, and good overall agreement is achieved. A consistency check of the two different models (based separately on clamped modal function and simply supported modal function) is performed by extending the panel dimensions to infinite where no boundaries exist. The significant discrepancies between the two different boundary conditions are demonstrated in terms of the STL versus frequency plots as well as the panel deflection mode shapes.

Sound-proof Sandwich Panel Design via Metamaterial Concept

Science.gov (United States)

Sui, Ni

the core material maintains the mechanical property and yields a sound transmission loss that is consistently greater than 50 dB at low frequencies. Furthermore, the absorption property of the proposed honeycomb sandwich panel was experimentally studied. The honeycomb sandwich panel shows an excellent sound absorbing performance at high frequencies by using reinforced glass fiber without adding too much mass. The effect of the panel size and the stiffness of the grid-like frame effect of the honeycomb sandwich structures on sound transmission are discussed lastly. For the second sound-proof sandwich panel design, each unit cell of the sandwich panel is replaced by a Helmholtz resonator by perforating a small hole on the top face sheet. A perfect sound absorber sandwich panel with coupled Helmholtz resonators is proposed by two types: single identical Helmholtz resonator in each unit cell and dual Helmholtz resonators with different orifices, arranged in each cell arranged periodically. The soundproof sandwich panel is modelled as a panel embedded in rigid panel and assumed as a semiinfinite space with hard boundary condition. The net/mutual impedance model is first proposed and derived by solving Kirchhoff-Helmholtz integral by using the Green's function. The thermal-viscous energy dissipation at the thermal boundary layer dominates the total energy consumed. Two types of perfect sound absorber sandwich panel are designed in the last part. Two theoretical methods: the average energy and the equivalent surface impedance method are used to predict sound absorption performance. The geometry for perfect sound absorber sandwich panel at a target frequency can be obtained when the all the Helmholtz resonators are at resonance and the surface impedance of the sandwich panel matches the air impedance. The bandwidth for the identical sandwich panel mainly depends on the neck radius. The absorptive property of the dual Helmholtz resonators type of sandwich panel is studied by

Three-dimensional dynamo-thermo-elastic analysis of a functionally graded cylindrical shell with piezoelectric layers by DQ-FD coupled

International Nuclear Information System (INIS)

Akbari Alashti, R.; Khorsand, M.

2012-01-01

Three-dimensional elastic analysis is carried out for functionally graded cylindrical shells bonded with piezoelectric layers subjected to dynamic and thermal loads. Material properties are assumed to be graded in the radial direction obeying a simple power law with constant Poisson's ratio. Two versions of differential quadrature (DQ) method coupled with the finite difference (FD) method are employed to discretize the governing differential equations in space and time domains. The convergence is studied and results of the axisymmetric loadings are verified with reported results. Effects of the grading index of material properties, thermal gradient, boundary conditions, thickness of piezoelectric layers and electric excitation on stress, displacement, electric and temperature fields are presented. Highlights: ► Dynamo-thermo-elastic analysis of an FGM shell with piezoelectric layer is carried out. ► Governing equations are solved by DQ-FD coupled. ► Effects of grading index, temperature difference and piezoelectric thickness are presented.

Elasto-Plastic Stress Analysis in Rotating Disks and Pressure Vessels Made of Functionally Graded Materials

Directory of Open Access Journals (Sweden)

Amir T. Kalali

Full Text Available Abstract A new elastio-plastic stress solution in axisymmetric problems (rotating disk, cylindrical and spherical vessel is presented. The rotating disk (cylindrical and spherical vessel was made of a ceramic/metal functionally graded material, i.e. a particle-reinforced composite. It was assumed that the material's plastic deformation follows an isotropic strain-hardening rule based on the von-Mises yield criterion. The mechanical properties of the graded material were modeled by the modified rule of mixtures. By assuming small strains, Hencky's stress-strain relation was used to obtain the governing differential equations for the plastic region. A numerical method for solving those differential equations was then proposed that enabled the prediction of stress state within the structure. Selected finite element results were also presented to establish supporting evidence for the validation of the proposed approach.

Performance comparison between silicon solar panel and dye-sensitized solar panel in Malaysia

Science.gov (United States)

Hamed, N. K. A.; Ahmad, M. K.; Urus, N. S. T.; Mohamad, F.; Nafarizal, N.; Ahmad, N.; Soon, C. F.; Ameruddin, A. S.; Faridah, A. B.; Shimomura, M.; Murakami, K.

2017-09-01

In carrying out experimental research in performance between silicon solar panel and dye-sensitive solar panel, we have been developing a device and a system. This system has been developed consisting of controllers, hardware and software. This system is capable to get most of the input sources. If only need to change the main circuit and coding for a different source input value. This device is able to get the ambient temperature, surface temperature, surrounding humidity, voltage with load, current with load, voltage without load and current without load and save the data into external memory. This device is able to withstand the heat and rain as it was fabricated in a waterproof box. This experiment was conducted to examine the performance of both the solar panels which are capable to maintain their stability and performance. A conclusion based on data populated, the distribution of data for dye-sensitized solar panel is much better than silicon solar panel as dye-sensitized solar panel is very sensitive to heat and not depend only on midday where is that is the maximum ambient temperature for both solar panel as silicon solar panel only can give maximum and high output only when midday.

Analysis of 3-panel and 4-panel microscale ionization sources

International Nuclear Information System (INIS)

Natarajan, Srividya; Parker, Charles B.; Glass, Jeffrey T.; Piascik, Jeffrey R.; Gilchrist, Kristin H.; Stoner, Brian R.

2010-01-01

Two designs of a microscale electron ionization (EI) source are analyzed herein: a 3-panel design and a 4-panel design. Devices were fabricated using microelectromechanical systems technology. Field emission from carbon nanotube provided the electrons for the EI source. Ion currents were measured for helium, nitrogen, and xenon at pressures ranging from 10 -4 to 0.1 Torr. A comparison of the performance of both designs is presented. The 4-panel microion source showed a 10x improvement in performance compared to the 3-panel device. An analysis of the various factors affecting the performance of the microion sources is also presented. SIMION, an electron and ion optics software, was coupled with experimental measurements to analyze the ion current results. The electron current contributing to ionization and the ion collection efficiency are believed to be the primary factors responsible for the higher efficiency of the 4-panel microion source. Other improvements in device design that could lead to higher ion source efficiency in the future are also discussed. These microscale ion sources are expected to find application as stand alone ion sources as well as in miniature mass spectrometers.

Cut-off frequencies of circumferential horizontal shear waves in various functionally graded cylinder shells.

Science.gov (United States)

Shen, Xiaoqin; Ren, Dawei; Cao, Xiaoshan; Wang, Ji

2018-03-01

In this study, cut-off frequencies of the circumferential SH waves in functionally graded piezoelectric-piezomagnetic material (FGPPM) cylinder shells with traction free, electrical and magnetic open boundary conditions are investigated analytically. The Wentzel-Kramers-Brillouin (WKB) method is employed for solving differential equations with variable coefficients for general cases. For comparison, Bessel functions and Kummer functions are used for solving cut-off frequency problems in homogenous and ideal FGPPM cylinder shells. It is shown that the WKB solution for the cut-off frequencies has good precise. The set of cut-off frequencies is a series of approximate arithmetic progressions, for which the difference is a function of the density and the effective elastic parameter. The relationship between the difference and the gradient coefficient is described. These results provide theoretical guidance for the non-destructive evaluation of curved shells based on the cut-off frequencies. Copyright © 2017 Elsevier B.V. All rights reserved.

EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013 . Scientific Opinion on the substantiation of a health claim related to VeriSol ® P and a change in skin elasticity leading to an improvement in skin function pursuant to Article 13(5) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

related to VeriSol®P and a change in skin elasticity leading to an improvement in skin function. The Panel considers that the food, VeriSol®P, which is the subject of the health claim, is sufficiently characterised. The claimed effect proposed by the applicant is “maintenance of skin health, as indicated...... by an increased skin elasticity and a reduction of wrinkles volume”. The target population proposed by the applicant is the general adult population. The Panel considers that a change in skin elasticity leading to an improvement in skin function is a beneficial physiological effect. The applicant presented two...... of VeriSol®P and a change in skin elasticity leading to an improvement in skin function. © European Food Safety Authority, 2013...

The modified couple stress functionally graded Timoshenko beam formulation

International Nuclear Information System (INIS)

Asghari, M.; Rahaeifard, M.; Kahrobaiyan, M.H.; Ahmadian, M.T.

2011-01-01

In this paper, a size-dependent formulation is presented for Timoshenko beams made of a functionally graded material (FGM). The formulation is developed on the basis of the modified couple stress theory. The modified couple stress theory is a non-classic continuum theory capable to capture the small-scale size effects in the mechanical behavior of structures. The beam properties are assumed to vary through the thickness of the beam. The governing differential equations of motion are derived for the proposed modified couple-stress FG Timoshenko beam. The generally valid closed-form analytic expressions are obtained for the static response parameters. As case studies, the static and free vibration of the new model are respectively investigated for FG cantilever and FG simply supported beams in which properties are varying according to a power law. The results indicate that modeling beams on the basis of the couple stress theory causes more stiffness than modeling based on the classical continuum theory, such that for beams with small thickness, a significant difference between the results of these two theories is observed.

Antinuclear antibody panel

Science.gov (United States)

... page: //medlineplus.gov/ency/article/003535.htm Antinuclear antibody panel To use the sharing features on this page, please enable JavaScript. The antinuclear antibody panel is a blood test that looks at ...

Hepatitis virus panel

Science.gov (United States)

... page: //medlineplus.gov/ency/article/003558.htm Hepatitis virus panel To use the sharing features on this page, please enable JavaScript. The hepatitis virus panel is a series of blood tests used ...

REINFORCED COMPOSITE PANEL

DEFF Research Database (Denmark)

2003-01-01

A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

Wear resistance and electrical properties of functionally graded epoxy-resin/silica composites

International Nuclear Information System (INIS)

Rihan, Y. A.; Abd El-Bary, B.

2012-12-01

In this paper graded Silica/Epoxy composite fabricated by controlled mold filling to obtain a stepwise graded structure. The generated graded structure was controlled by the w 1% content of silica particulates of size range from (45 μm-250 μm). Microstructural characterization was conducted using Scanning Electron Microscope (SEM). Electrical properties were conducted in High Voltage-Lab using Sphere-Plate Electrode System and Insulating resistance equipment s. Wear characteristics were studied using Block-on-Ring wear testing machine for the different layers of the graded silica/epoxy composites, The prepared materials are used as coating materials for the floors of chemical laboratories. (Author)

Facade renovation - replacement and restoration of the panels in a monument protected object

Science.gov (United States)

Novotný, Michal

2017-12-01

The article deals with problems of reconstruction of the facade and the associated problem of replacement or repair of the panels. In conventional buildings it is a smooth operation, but it is problematic in monument-protected objects. In the case of a common building, it is possible to choose any modern panels and simply replace them, but for historical objects we have to follow the claims and the rules of monument protection. In practice, it usually means the impossibility of use of modern panels, but at least a combination of old and modern technologies. Another possible solution to the problem is renovation, or repairs to the original state of the existing panels, of course with respect to the functionality of such panels. The implementation of such repairs must always be based on the technical and historical survey of the condition of the object and the repairs must be professionally designed. Subsequently, corrections are made, during which it is necessary to pay particular attention to observance of the technological procedures, rules and instructions particularly in terms of monument protection. However, the functionality of the works or elements made with regard to the quality of the environment within the building is not negligible. A common problem is the lack of control of technical requirements and functional requirements. Underestimation of the problems then leads to difficult repairs. The article points to the mistakes and problems of one such construction project on a historically protected chateau building.

Rational Design of Composite Panels

DEFF Research Database (Denmark)

Riber, Hans Jørgen

1996-01-01

A non-linear structural model for composite panels is presented. The non-linear terms in the lateral displacements are modelled as an additional set of lateral loads acting on the panel. Hence the solution is reduced to that of an equivalent panel with small displacements In order to treat sandwich...... Norske Veritas', DNV, building rules concerning high-speed light craft, in which the panel scantlings are often restricted by a maximum lateral deflection connected with the panel span....

Review of therapeutic agents for burns pruritus and protocols for management in adult and paediatric patients using the GRADE classification

Directory of Open Access Journals (Sweden)

Goutos Ioannis

2010-10-01

Full Text Available To review the current evidence on therapeutic agents for burns pruritus and use the Grading of Recommendations, Assessment, Development and Evaluation (GRADE classification to propose therapeutic protocols for adult and paediatric patients. All published interventions for burns pruritus were analysed by a multidisciplinary panel of burns specialists following the GRADE classification to rate individual agents. Following the collation of results and panel discussion, consensus protocols are presented. Twenty-three studies appraising therapeutic agents in the burns literature were identified. The majority of these studies (16 out of 23 are of an observational nature, making an evidence-based approach to defining optimal therapy not feasible. Our multidisciplinary approach employing the GRADE classification recommends the use of antihistamines (cetirizine and cimetidine and gabapentin as the first-line pharmacological agents for both adult and paediatric patients. Ondansetron and loratadine are the second-line medications in our protocols. We additionally recommend a variety of non-pharmacological adjuncts for the perusal of clinicians in order to maximise symptomatic relief in patients troubled with postburn itch. Most studies in the subject area lack sufficient statistical power to dictate a ′gold standard′ treatment agent for burns itch. We encourage clinicians to employ the GRADE system in order to delineate the most appropriate therapeutic approach for burns pruritus until further research elucidates the most efficacious interventions. This widely adopted classification empowers burns clinicians to tailor therapeutic regimens according to current evidence, patient values, risks and resource considerations in different medical environments.

Composite panel development at JPL

Science.gov (United States)

Mcelroy, Paul; Helms, Rich

1988-01-01

Parametric computer studies can be use in a cost effective manner to determine optimized composite mirror panel designs. An InterDisciplinary computer Model (IDM) was created to aid in the development of high precision reflector panels for LDR. The materials properties, thermal responses, structural geometries, and radio/optical precision are synergistically analyzed for specific panel designs. Promising panels designs are fabricated and tested so that comparison with panel test results can be used to verify performance prediction models and accommodate design refinement. The iterative approach of computer design and model refinement with performance testing and materials optimization has shown good results for LDR panels.

Investigation of static and dynamic behavior of functionally graded piezoelectric actuated Poly-Si micro cantilever probe

Energy Technology Data Exchange (ETDEWEB)

Pandey, Vibhuti Bhushan; Parashar, Sandeep Kumar, E-mail: skparashar@rtu.ac.in [Department of Mechanical Engineering, Rajasthan Technical University, Kota (India)

2016-04-13

In the present paper a novel functionally graded piezoelectric (FGP) actuated Poly-Si micro cantilever probe is proposed for atomic force microscope. The shear piezoelectric coefficient d{sub 15} has much higher value than coupling coefficients d{sub 31} and d{sub 33}, hence in the present work the micro cantilever beam actuated by d{sub 15} effect is utilized. The material properties are graded in the thickness direction of actuator by a simple power law. A three dimensional finite element analysis has been performed using COMSOL Multiphysics® (version 4.2) software. Tip deflection and free vibration analysis for the micro cantilever probe has been done. The results presented in the paper shall be useful in the design of micro cantilever probe and their subsequent utilization in atomic force microscopes.

Supersonic Panel Flutter Test Results for Flat Fiber-Glass Sandwich Panels with Foamed Cores

Science.gov (United States)

Tuovila, W. J.; Presnell, John G., Jr.

1961-01-01

Flutter tests have been made on flat panels having a 1/4 inch-thick plastic-foam core covered with thin fiber-glass laminates. The testing was done in the Langley Unitary Plan wind tunnel at Mach numbers from 1.76 t o 2.87. The flutter boundary for these panels was found to be near the flutter boundary of thin metal panels when compared on the basis of an equivalent panel stiffness. The results also demonstrated that the depth of the cavity behind the panel has a pronounced influence on flutter. Changing the cavity depth from 1 1/2 inches to 1/2 inch reduced the dynamic pressure at start of flutter by 40 percent. No flutter was obtained when the spacers on the back of the panel were against the bottom of the cavity.

Panel Resource Management (PRM) Implementation and Effects within Safety Review Panel Settings and Dynamics

Science.gov (United States)

Taylor, Robert W.; Nash, Sally K.

2007-01-01

While technical training and advanced degree's assure proficiency at specific tasks within engineering disciplines, they fail to address the potential for communication breakdown and decision making errors familiar to multicultural environments where language barriers, intimidating personalities and interdisciplinary misconceptions exist. In an effort to minimize these pitfalls to effective panel review, NASA's lead safety engineers to the ISS Safety Review Panel (SRP), and Payload Safety Review Panel (PSRP) initiated training with their engineers, in conjunction with the panel chairs, and began a Panel Resource Management (PRM) program. The intent of this program focuses on the ability to reduce the barriers inhibiting effective participation from all panel attendees by bolstering participants confidence levels through increased communication skills, situational awareness, debriefing, and a better technical understanding of requirements and systems.

Potential Applications of Flat-Panel Volumetric CT in Morphologic, Functional Small Animal Imaging

Directory of Open Access Journals (Sweden)

Susanne Greschus

2005-08-01

Full Text Available Noninvasive radiologic imaging has recently gained considerable interest in basic, preclinical research for monitoring disease progression, therapeutic efficacy. In this report, we introduce flat-panel volumetric computed tomography (fpVCT as a powerful new tool for noninvasive imaging of different organ systems in preclinical research. The three-dimensional visualization that is achieved by isotropic high-resolution datasets is illustrated for the skeleton, chest, abdominal organs, brain of mice. The high image quality of chest scans enables the visualization of small lung nodules in an orthotopic lung cancer model, the reliable imaging of therapy side effects such as lung fibrosis. Using contrast-enhanced scans, fpVCT displayed the vascular trees of the brain, liver, kidney down to the subsegmental level. Functional application of fpVCT in dynamic contrast-enhanced scans of the rat brain delivered physiologically reliable data of perfusion, tissue blood volume. Beyond scanning of small animal models as demonstrated here, fpVCT provides the ability to image animals up to the size of primates.

Solar panel cleaning robot

Science.gov (United States)

Nalladhimmu, Pavan Kumar Reddy; Priyadarshini, S.

2018-04-01

As the demand of electricity is increasing, there is need to using the renewable sources to produce the energy at present of power shortage, the use of solar energy could be beneficial to great extent and easy to get the maximum efficiency. There is an urgent in improving the efficiency of solar power generation. Current solar panels setups take a major power loss when unwanted obstructions cover the surface of the panels. To make solar energy more efficiency of solar array systems must be maximized efficiency evaluation of PV panels, that has been discussed with particular attention to the presence of dust on the efficiency of the PV panels have been highlighted. This paper gives the how the solar panel cleaning system works and designing of the cleaning system.

Ergonomic Redesign of an Industrial Control Panel

Directory of Open Access Journals (Sweden)

S Raeisi

2016-07-01

Full Text Available Operator's role in industrial control centers takes place in time, which is one of the most important determinants of whether an expected action is going to be successful or not. In certain situations, due to the complex nature of the work, the existing interfaces and already prepared procedures do not meet the dynamic requirements of operator's cognitive demands, making the control tasks unnecessarily difficult. This study was conducted to identify ergonomic issues with a specific industrial control panel, and redesign its layout and elements to enhance its usability. Task and link analysis methodologies were implemented. All essential functions and supporting operations were identified at the required trivial levels. Next, the weight of any possible link between the elements of the panel was computed as a composite index of frequency and importance. Finally, all components were rearranged within a new layout, and a computerized mockup was generated. A total of 8 primary tasks was identified, including 4 system failure handling tasks, switching between manual and automated modes, and 3 types of routine vigilance and control tasks. These tasks were broken down into 28 functions and 145 supporting operations, accordingly. Higher link values were observed between hand rest position and 2 elements. Also, 6 other components showed robust linkages. In conclusion, computer modeling can reduce the likelihood of accidents and near misses in industrial control rooms by considering the operators' misperception or mental burden and correcting poor design of the panels and inappropriate task allocation.

Lightweight, Thermally Insulating Structural Panels

Science.gov (United States)

Eisen, Howard J.; Hickey, Gregory; Wen, Liang-Chi; Layman, William E.; Rainen, Richard A.; Birur, Gajanana C.

1996-01-01

Lightweight, thermally insulating panels that also serve as structural members developed. Honeycomb-core panel filled with low-thermal-conductivity, opacified silica aerogel preventing convection and minimizes internal radiation. Copper coating on face sheets reduces radiation. Overall thermal conductivities of panels smaller than state-of-art commercial non-structurally-supporting foam and fibrous insulations. On Earth, panels suitable for use in low-air-pressure environments in which lightweight, compact, structurally supporting insulation needed; for example, aboard high-altitude aircraft or in partially evacuated panels in refrigerators.

Cognitive self-regulation and social functioning among French children: A longitudinal study from kindergarten to first grade.

Science.gov (United States)

Hubert, Blandine; Guimard, Philippe; Florin, Agnès

2017-03-01

This study adds to the body of research examining the links between two components of cognitive self-regulation (inhibitory control and verbal working memory) and social functioning (social integration, social problem solving, and prosocial skills) and focuses on children's sex as a moderator of the association between cognitive self-regulation and social functioning. The participants (N = 131) were French schoolchildren followed from kindergarten (Mage = 68.36 months, SD = 3.33 months) through Grade 1. Using hierarchical regression analyses, three major findings were revealed: (1) inhibitory control was a better predictor than verbal working memory of prosocial skills assessed by peers using the sociometric technique as well as by teachers using questionnaires, after controlling for sex, mother's education, and verbal and non-verbal IQ; (2) the prosocial skills assessed by teachers in kindergarten contributed more to explaining the prosocial skills and peer acceptance assessed in Grade 1 than cognitive self-regulation; and (3) sex did not moderate the relationship between cognitive self-regulation and social functioning. These results suggest that developing strong cognitive self-regulation, especially inhibitory control and prosocial skills, in young children schooled in France could be beneficial for their social development. © 2017 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

PERBANDINGAN UNJUK KERJA ANTARA PANEL SEL SURYA BERPENJEJAK DENGAN PANEL SEL SURYA DIAM

OpenAIRE

Syafaruddin Ch

2010-01-01

The ability to produce electrical energy at Solar Power Plant  is highly dependent on the magnitude and duration of sun exposure on the solar cell panels. The movement of the sun from east to west that periodicity in every day is a problem at  the  optimization generation of electricity at  Solar Power Plant   if using solar panel that motionless. This is because the solar cell panel can not catch the maximum sun exposure. To solve the above problem then designed a solar cell panel  tracker...

Loss of Consciousness at Onset of Aneurysmal Subarachnoid Hemorrhage is Associated with Functional Outcomes in Good-Grade Patients

NARCIS (Netherlands)

Wang, Justin; Alotaibi, Naif M.; Akbar, Muhammad Ali; Ayling, Oliver G S; Ibrahim, George M.; Macdonald, R. Loch; Noble, Adam; Molyneux, Andrew; Quinn, Audrey; Schatlo, Bawarjan; Lo, Benjamin; Jaja, Blessing N R; Johnston, Clay; Hanggi, Daniel; Hasan, David; Wong, George K C; Lantigua, Hector; Fukuda, Hitoshi; Torner, James; Singh, Jeff; Spears, Julian; Schaller, Karl; Stienen, Martin N.; Vergouwen, Mervyn D I; Cusimano, Michael D.; Todd, Michael; Tseng, Ming; Le Roux, Peter; Macdonald, R. Loch; Yamagata, Sen; Mayer, Stephan; Schenk, Thomas; Schweizer, Tom A.

2017-01-01

Background Transient loss of consciousness (LOC) is one of the most common presentations of aneurysmal subarachnoid hemorrhage (SAH) and may be an indicator of early brain injury. In this study, we examined the association of LOC and functional outcomes in patients with good-grade SAH. Methods We

A multicolor panel of novel lentiviral "gene ontology" (LeGO) vectors for functional gene analysis.

Science.gov (United States)

Weber, Kristoffer; Bartsch, Udo; Stocking, Carol; Fehse, Boris

2008-04-01

Functional gene analysis requires the possibility of overexpression, as well as downregulation of one, or ideally several, potentially interacting genes. Lentiviral vectors are well suited for this purpose as they ensure stable expression of complementary DNAs (cDNAs), as well as short-hairpin RNAs (shRNAs), and can efficiently transduce a wide spectrum of cell targets when packaged within the coat proteins of other viruses. Here we introduce a multicolor panel of novel lentiviral "gene ontology" (LeGO) vectors designed according to the "building blocks" principle. Using a wide spectrum of different fluorescent markers, including drug-selectable enhanced green fluorescent protein (eGFP)- and dTomato-blasticidin-S resistance fusion proteins, LeGO vectors allow simultaneous analysis of multiple genes and shRNAs of interest within single, easily identifiable cells. Furthermore, each functional module is flanked by unique cloning sites, ensuring flexibility and individual optimization. The efficacy of these vectors for analyzing multiple genes in a single cell was demonstrated in several different cell types, including hematopoietic, endothelial, and neural stem and progenitor cells, as well as hepatocytes. LeGO vectors thus represent a valuable tool for investigating gene networks using conditional ectopic expression and knock-down approaches simultaneously.

Panel data analysis using EViews

CERN Document Server

Agung, I Gusti Ngurah

2013-01-01

A comprehensive and accessible guide to panel data analysis using EViews software This book explores the use of EViews software in creating panel data analysis using appropriate empirical models and real datasets. Guidance is given on developing alternative descriptive statistical summaries for evaluation and providing policy analysis based on pool panel data. Various alternative models based on panel data are explored, including univariate general linear models, fixed effect models and causal models, and guidance on the advantages and disadvantages of each one is given. Panel Data Analysis

The Hijdra scale has significant prognostic value for the functional outcome of Fisher grade 3 patients with subarachnoid hemorrhage.

Science.gov (United States)

Bretz, Julia S; Von Dincklage, Falk; Woitzik, Johannes; Winkler, Maren K L; Major, Sebastian; Dreier, Jens P; Bohner, Georg; Scheel, Michael

2017-09-01

Despite its high prevalence among patients with aneurysmal subarachnoid hemorrhage (aSAH) and high risk of delayed cerebral ischemia (DCI), the Fisher grade 3 category remains a poorly studied subgroup. The aim of this cohort study has been to investigate the prognostic value of the Hijdra sum scoring system for the functional outcome in patients with Fisher grade 3 aSAH, in order to improve the risk stratification within this Fisher category. Initial CT scans of 72 prospectively enrolled patients with Fisher grade 3 aSAH were analyzed, and cisternal, ventricular, and total amount of blood were graded according to the Hijdra scale. Additionally, space-occupying subarachnoid blood clots were assessed. Outcome was evaluated after 6 months. Within the subgroup of Fisher grade 3, aSAH patients with an unfavorable outcome showed a significantly larger cisternal Hijdra sum score (HSS: 21.1 ± 5.2) than patients with a favorable outcome (HSS: 17.6 ± 5.9; p = 0.009). However, both the amount of ventricular blood (p = 0.165) and space-occupying blood clots (p = 0.206) appeared to have no prognostic relevance. After adjusting for the patient's age, gender, tobacco use, clinical status at admission, and presence of intracerebral hemorrhage, the cisternal and total HSS remained the only independent parameters included in multivariate logistic regression models to predict functional outcome (p Fisher 3 category. We suggest that the Hijdra scale is a practically useful prognostic instrument for the risk evaluation after aSAH and should be applied more often in the clinical setting.

Cleaning Robot for Solar Panels in Solar Power Station

Science.gov (United States)

Hang, Lu-Bin; Shen, Cheng-Wei; Bian, Huai-Qiang; Wang, Yan

2016-05-01

The dust particles on solar panel surface have been a serious problem for the photovoltaic industry, a new monorail-tracked robot used for automatic cleaning of solar panel is presented in this paper. To meet the requirement of comprehensive and stable cleaning of PV array, the monorail-tracked pattern of robot is introduced based on the monorail structure technique. The running and striding mechanism are designed for mobility of robot on the solar panels. According to the carrying capacity and water circulation mechanism, a type of self-cleaning device with filtering system is developed. Combined with the computer software and communications technology, the control system is built in this robot, which can realize the functions of autonomous operation, positioning and monitoring. The application of this developed cleaning robot can actualize the Industrialization of automatic cleaning for PV components and have wide market prospect.

RECIPANEL: RECYCLED PAPER PANELS

Directory of Open Access Journals (Sweden)

HERNÁN CAÑOLA

2012-01-01

Full Text Available En este artículo se estudia la fabricación y el comportamiento mecánico de paneles a base de papel reciclado. El objetivo principal del proyecto es producir un prototipo de panel que emplee elementos provenientes de residuos sólidos (papel periódico y de un material conglomerante (cemento Portland blanco. El panel debe ser económico, debe tener buenas propiedades mecánicas y debe tener dimensiones comerciales para su uso en muros tabiques y en cielos falsos en la industria de la construcción. El Recipanel es un panel no estructural a base de papel reciclado. El Recipanel cumple las normas colombianas en lo relativo a los paneles de uso no estructural y presenta además unas excelentes características mecánicas.

Collegiate Grading Practices and the Gender Pay Gap.

Science.gov (United States)

Dowd, Alicia C.

2000-01-01

Presents a theoretical analysis showing that relatively low grading quantitative fields and high grading verbal fields create a disincentive for college women to invest in quantitative study. Extends research by R. Sabot and J. Wakeman-Linn. Models pressures on grading practices using higher education production functions. (Author/SLD)

A revision of the Cormack and Lehane laryngoscopic grading system with special consideration to grade II laryngoscopic view

Directory of Open Access Journals (Sweden)

Hussain khan Z

2007-10-01

Full Text Available Background: The major responsibility of an anesthesiologist is to provide adequate respiration for the patient. The most vital element in providing functional respiration is the airway. No anesthetic is safe unless diligent efforts are devoted to maintaining an intact functional airway. Difficult intubation had been classified into four grades, according to the view obtainable at laryngoscopy by Cormack and Lehane in 1984. This grading system has been in use to evaluate and manage those patients with difficult airway by anesthesiologists. In clinical state, grades III and IV are quite rare, so the need for a modified Cormack and Lehane grading system was felt. The use of a modified Cormack-Lehane scoring system of laryngoscopic views during direct laryngoscopy, was previously examined in the Western population. Koh and his co-workers had examined this modified Cormack and Lehane grading system in Asian population in a study in Singapore General Hospital. The aim of this study was to investigate this scoring system in Iranian patients.Methods: In a cross sectional study, a modified version of the Cormack and Lehane grading system was evaluated in 300 patients requiring tracheal intubation. In the modified system, grade II (only part of the glottis is visible was divided into IIa (part of the cords is visible and IIb (only the arytenoids or the very posterior origin of the cords are visible. Difficult intubation was defined as requiring more than one laryngoscopy or the use of special equipments.Results: Sixty eight patients (22.7% were scored as grade IIa and 32 (7.7% as grade IIb. The prevalence of difficult intubation in grade IIb was significantly higher than patients in group IIa (47.8% vs. 2.9% respectively, Fisher's exact test, p= 0.001Conclusion: The modified grading system provides more information than the original Cormack and Lehane system."n 

Stress wave propagation in thin long-fiber carbon/epoxy composite panel. Numerical and experimental solutions

Directory of Open Access Journals (Sweden)

Kroupa T.

2007-10-01

Full Text Available The article deals with experimental and numerical analysis of stress wave propagation in a thin long fiber carbon/epoxy composite material. Experiments were performed on in-plane loaded square composite panels with dimensions 501mm x 501mm x 2:2 mm. The panels have several fiber orientations (0°, 30°, 60° and 90° measured from the loaded edge. They were loaded by in-plane impact of steel sphere. The impact area was on the edge, exactly 150mm from top left corners corner of the panels. The loading force was approximated by atime dependent function. Its shape was obtained from three dimensional contact analysis, which was performed on smaller area of panel. The function was used in further plane stress analysis of the whole panels. The comparison of the numerical and experimental results was executed. An attempt at determination of velocity of propagation of Rayleigh waves on the loaded edge was performed and the results are discussed in the paper. Further directions of the research are proposed.

Evaluation of veneer yields and grades from yellow-poplar, white oak, and sweetgum from the southeast

Science.gov (United States)

Robert H. McAlister

1980-01-01

Dry volume yields and standard grades of veneer are given for yellow-poplar, sweetgum, and white oak by tree diameter and location within the stem. Results show that the typical stands of mixed southern pine and hardwood timer yield enough veneer to utilize almost 90 percent of the stand volume in the production of COM-PLY lumber and panels

High-grade ovarian cancer secreting effective exosomes in tumor angiogenesis.

Science.gov (United States)

Yi, Huan; Ye, Jun; Yang, Xiao-Mei; Zhang, Li-Wen; Zhang, Zhi-Gang; Chen, Ya-Ping

2015-01-01

Ovarian cancer, the most lethal gynecological cancer, related closely to tumor stage. High-grade ovarian cancer always results in a late diagnose and high recurrence, which reduce survival within five years. Until recently, curable therapy is still under research and anti-angiogenesis proves a promising way. Tumor-derived exosomes are essential in tumor migration and metastases such as angiogenesis is enhanced by exosomes. In our study, we have made comparison between high-grade and unlikely high-grade serous ovarian cancer cells on exosomal function of endothelial cells proliferation, migration and tube formation. Exosomes derived from high-grade ovarian cancer have a profound impact on angiogenesis with comparison to unlikely high-grade ovarian cancer. Proteomic profiles revealed some potential proteins involved in exosomal function of angiogenesis such as ATF2, MTA1, ROCK1/2 and so on. Therefore, exosomes plays an influential role in angiogenesis in ovarian serous cancer and also function more effectively in high-grade ovarian cancer cells.

Dry Sliding Wear Behavior of A356 Alloy/Mg2Sip Functionally Graded in-situ Composites: Effect of Processing Conditions

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S.C. Ram

2016-09-01

Full Text Available In present study, the effect of dry sliding wear conditions of A356 alloy/Mg2Sip functionally graded in-situ composites developed by centrifugal casting method has been studied. A pure commercial A356 alloy (Al–7.5Si–0.3Mg was selected to be the matrix of the composites and primary Mg2Sip reinforcing particles were formed by in-situ chemical reaction with an average grain size of 40-47.8 µm. The Al–(Mg2Sip functionally graded metal matrix composites (FGMMC’s were synthesized by centrifugal casting technique with radial geometry, using two different mould rotating speeds ( 1200 and 1600 rpm. The X-ray diffraction (XRD characterization technique was carried out to confirm the in-situ formed Mg2Si particles in composites. Optical microscopy examination was carried out to reveals the grain refinement of Al-rich grains due to in-situ formed Mg2Si particles. Scanning electron microscope (SEM and Energy dispersive X-ray spectroscopy (EDS techniques were carried out to reveal the distribution of phases, morphological characteristics and confirmation of primary Mg2Si particles in the matrix. The sliding wear behavior was studied using a Pin-on-Disc set-up machine with sliding wear parameters: effect of loads (N, effect of sliding distances (m and effect of Mg on wear at room temperature with a high-carbon chromium steel disc (HRC-64 as counter surfaces. A good correlation was evidenced between the dry sliding behaviour of functionally graded in-situ composites and the distribution of Mg2Si reinforcing particles. Beside the above processing conditions, the dominant wear mechanisms of functionally graded in-situ composites have been correlated with the microstructures. The hardness and wear resistance properties of these composites increase with increasing volume percent of reinforced primary Si/Mg2Si particles toward inner zone of cast cylindrical shapes. The objective of this works was to study the tribological characteristics under dry sliding

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

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Zhong-Qi Yue

2012-01-01

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

First grade classroom-level adversity: Associations with teaching practices, academic skills, and executive functioning.

Science.gov (United States)

Abry, Tashia; Granger, Kristen L; Bryce, Crystal I; Taylor, Michelle; Swanson, Jodi; Bradley, Robert H

2018-05-24

Using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development and a model-building approach, the authors examined direct and indirect associations between first-grade (G1) classroom-level adversity (CLA), G1 teaching practices, and student (N = 1,073; M = 6.64 years; 49% girls; 82% White) academic skills and executive functioning in G1 and third grades (G3). Teachers reported the prevalence of adversity among their students (e.g., poor home/family life, poor academic/social readiness). Observers rated G1 teaching practices: teachers' classroom management, controlling instruction, and amount of academic instruction (classroom observation system). Children completed literacy and math assessments at 54 months, G1, and G3 (Woodcock Johnson Letter-Word Identification and Applied Problems), and executive functioning at G1 and G3 (Tower of Hanoi). Direct associations emerged between CLA and controlling instruction (positive), classroom management, and academic instruction (both negative). In addition, CLA was related to G1 literacy (but not math) directly and indirectly via classroom management (negatively) and controlling instruction (positively). The addition of G3 outcomes revealed a negative direct longitudinal association between CLA and G3 executive functioning, and indirect associations with G3 literacy and math through G1 teaching practices and literacy. Results support the notion that collective student characteristics influence student outcomes in part through teaching practices and suggest that teachers and students may benefit from the diffusion of high-adversity classroom compositions when possible. Moreover, in high-adversity classrooms teachers and students may benefit from supports targeting classroom management and foundational student competencies. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Fracture Behavior and Properties of Functionally Graded Fiber-Reinforced Concrete

International Nuclear Information System (INIS)

Roesler, Jeffery; Bordelon, Amanda; Gaedicke, Cristian; Park, Kyoungsoo; Paulino, Glaucio

2008-01-01

In concrete pavements, a single concrete mixture design is selected to resist mechanical loading without attempting to adversely affect the concrete pavement shrinkage, ride quality, or noise attenuation. An alternative approach is to design distinct layers within the concrete pavement surface which have specific functions thus achieving higher performance at a lower cost. The objective of this research was to address the structural benefits of functionally graded concrete materials (FGCM) for rigid pavements by testing and modeling the fracture behavior of different combinations of layered plain and synthetic fiber-reinforced concrete materials. Fracture parameters and the post-peak softening behavior were obtained for each FGCM beam configuration by the three point bending beam test. The peak loads and initial fracture energy between the plain, fiber-reinforced, and FGCM signified similar crack initiation. The total fracture energy indicated improvements in fracture behavior of FGCM relative to full-depth plain concrete. The fracture behavior of FGCM depended on the position of the fiber-reinforced layer relative to the starter notch. The fracture parameters of both fiber-reinforced and plain concrete were embedded into a finite element-based cohesive zone model. The model successfully captured the experimental behavior of the FGCMs and predicted the fracture behavior of proposed FGCM configurations and structures. This integrated approach (testing and modeling) demonstrates the viability of FGCM for designing layered concrete pavements system

Solar panel parallel mounting configuration

Science.gov (United States)

Mutschler, Jr., Edward Charles (Inventor)

1998-01-01

A spacecraft includes a plurality of solar panels interconnected with a power coupler and an electrically operated device to provide power to the device when the solar cells are insolated. The solar panels are subject to bending distortion when entering or leaving eclipse. Spacecraft attitude disturbances are reduced by mounting each of the solar panels to an elongated boom made from a material with a low coefficient of thermal expansion, so that the bending of one panel is not communicated to the next. The boom may be insulated to reduce its bending during changes in insolation. A particularly advantageous embodiment mounts each panel to the boom with a single mounting, which may be a hinge. The single mounting prevents transfer of bending moments from the panel to the boom.

Fracture of functionally graded materials: application to hydrided zircaloy

International Nuclear Information System (INIS)

Perales, F.

2005-12-01

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

Seismic hazard analysis. Review panel, ground motion panel, and feedback results

International Nuclear Information System (INIS)

Bernreuter, D.L.

1981-10-01

The Site Specific Spectra Project (SSSP) was a multi-year study funded by the U.S. Nuclear Regulatory Commission to provide estimates of the seismic hazards at a number of nuclear power plant sites in the Eastern U.S. A key element of our approach was the Peer Review Panel, which we formed in order to ensure that our use of expert opinion was reasonable. We discuss the Peer Review Panel results and provide the complete text of each member's report. In order to improve the ground motion model, an Eastern U.S. Ground Motion Model Panel was formed. In Section 4 we tabulate the responses from the panel members to our feedback questionnaire and discuss the implications of changes introduced by them. We conclude that the net difference in seismic hazard values from those presented in Volume 4 is small and does not warrant a reanalysis. (author)

Mounting clips for panel installation

Science.gov (United States)

Cavieres, Andres; Al-Haddad, Tristan; Goodman, Joseph

2017-07-11

A photovoltaic panel mounting clip comprising a base, central indexing tabs, flanges, lateral indexing tabs, and vertical indexing tabs. The mounting clip removably attaches one or more panels to a beam or the like structure, both mechanically and electrically. It provides secure locking of the panels in all directions, while providing guidance in all directions for accurate installation of the panels to the beam or the like structure.

How preschool executive functioning predicts several aspects of math achievement in Grades 1 and 3: A longitudinal study.

Science.gov (United States)

Viterbori, Paola; Usai, M Carmen; Traverso, Laura; De Franchis, Valentina

2015-12-01

This longitudinal study analyzes whether selected components of executive function (EF) measured during the preschool period predict several indices of math achievement in primary school. Six EF measures were assessed in a sample of 5-year-old children (N = 175). The math achievement of the same children was then tested in Grades 1 and 3 using both a composite math score and three single indices of written calculation, arithmetical facts, and problem solving. Using previous results obtained from the same sample of children, a confirmatory factor analysis examining the latent EF structure in kindergarten indicated that a two-factor model provided the best fit for the data. In this model, inhibition and working memory (WM)-flexibility were separate dimensions. A full structural equation model was then used to test the hypothesis that math achievement (the composite math score and single math scores) in Grades 1 and 3 could be explained by the two EF components comprising the kindergarten model. The results indicate that the WM-flexibility component measured during the preschool period substantially predicts mathematical achievement, especially in Grade 3. The math composite scores were predicted by the WM-flexibility factor at both grade levels. In Grade 3, both problem solving and arithmetical facts were predicted by the WM-flexibility component. The results empirically support interventions that target EF as an important component of early childhood mathematics education. Copyright © 2015 Elsevier Inc. All rights reserved.

Semi-analytical Vibration Characteristics of Rotating Timoshenko Beams Made of Functionally Graded Materials

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Farzad Ebrahimia

Full Text Available AbstractFree vibration analysis of rotating functionally graded (FG thick Timoshenko beams is presented. The material properties of FG beam vary along the thickness direction of the constituents according to power law model. Governing equations are derived through Hamilton's principle and they are solved applying differential transform method. The good agreement between the results of this article and those available in literature validated the presented approach. The emphasis is placed on investigating the effect of several beam parameters such as constituent volume fractions, slenderness ratios, rotational speed and hub radius on natural frequencies and mode shapes of the rotating thick FG beam.

Three-dimensional inverse transient heat transfer analysis of thick functionally graded plates

Energy Technology Data Exchange (ETDEWEB)

Haghighi, M.R. Golbahar; Malekzadeh, P. [Department of Mechanical Engineering, School of Engineering, Persian Gulf University, Bushehr 75168 (Iran); Eghtesad, M. [Department of Mechanical Engineering, School of Engineering, Shiraz University, Shiraz 71348-51154 (Iran); Necsulescu, D.S. [Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Ontario (Canada)

2009-03-15

In this paper, a three-dimensional transient inverse heat conduction (IHC) procedure is presented to estimate the unknown boundary heat flux of thick functionally graded (FG) plates. For this purpose, the conjugate gradient method (CGM) in conjunction with adjoint problem is used. A recently developed three-dimensional efficient hybrid method is employed to solve variable-coefficient initial-boundary-value differential equations of direct problem as a part of the inverse solution. The accuracy of the inverse analysis is examined by simulating the exact and noisy data for problems with different types of boundary conditions and material properties. In addition to rectangular domain, skew plates are considered. The results obtained show good accuracy for the estimation of boundary heat fluxes. (author)

3D Energy Absorption Diagram Construction of Paper Honeycomb Sandwich Panel

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Dongmei Wang

2018-01-01

Full Text Available Paper honeycomb sandwich panel is an environment-sensitive material. Its cushioning property is closely related to its structural factors, the temperature and humidity, random shocks, and vibration events in the logistics environment. In order to visually characterize the cushioning property of paper honeycomb sandwich panel in different logistics conditions, the energy absorption equation of per unit volume of paper honeycomb sandwich panel was constructed by piecewise function. The three-dimensional (3D energy absorption diagram of paper honeycomb sandwich panel was constructed by connecting the inflexion of energy absorption curve. It takes into account the temperature, humidity, strain rate, and characteristics of the honeycomb structure. On the one hand, this diagram breaks through the limitation of the static compression curve of paper honeycomb sandwich panel, which depends on the test specimen and is applicable only to the standard condition. On the other hand, it breaks through the limitation of the conventional 2D energy absorption diagram which has less information. Elastic modulus was used to normalize the plateau stress and energy absorption per unit volume. This makes the 3D energy absorption diagram universal for different material sandwich panels. It provides a new theoretical basis for packaging optimized design.

Collegiate Grading Practices and the Gender Pay Gap

Directory of Open Access Journals (Sweden)

Alicia C. Dowd

2000-01-01

Full Text Available Extending research findings by R. Sabot and J. Wakeman-Linn (1991, this article presents a theoretical analysis showing that relatively low grading quantitative fields and high grading verbal fields create a disincentive for college women to invest in quantitative study. Pressures on grading practices are modeled using higher education production functions.

Ergonomic evaluation of CRT display in new control panels for nuclear power stations

International Nuclear Information System (INIS)

Kabazawa, Yoshihiko

1983-01-01

New control panels are to support powerfully the synthetic judgement function of operators by processing enormous plant data in the normal operation and at the time of accidents in nuclear power stations, and displaying the results in collective and ordered form on CRTs. This time, by carrying out the evaluation of new control panels using human engineering method, it was able to be confirmed that the new control panels have achieved the initial objectives, and to determine the criteria for the ergonomic evaluation of central control panels mainly with CRT display. Besides, it is considered that the application to wide range can be expected for this evaluation, not only to the CRT display system of the new control panels for nuclear power stations but also to other CRT images, therefore, the outline is reported. Chubu Electric Power Co., Inc. plans to adopt the new control panels with CRT display effectively utilizing process computers hereafter. It is necessary to give sufficient consideration to the method of using CRT images, the kinds of displayed images, colors and the form and arrangement of letters and symbols. 12 CRTs are used for the new control panel. The results are reflected to the control panel for Hamaoka No.3 plant. (Kako, I.)

Analysis and Behaviour of Sandwich Panels with Profiled Metal Facings under Transverse Load

Directory of Open Access Journals (Sweden)

M. Budescu

2004-01-01

Full Text Available Sandwich panels with thin steel facings and polyurethane core combine the load-carrying capacity of metal facings and protection functions with core properties. The core separates the two facings and keeps them in a stable condition, transmits shear between external layers, provides most of the shear rigidity and occasionally makes of useful contribution to the bending stiffness of the sandwich construction as a whole [1]. An experimental program on sandwich panels has been organized to prove that the mechanical properties of core and interface satisfy the load-carrying requirements for structural sandwich panels. The analysis of sandwich panels with deep profiles facings for cladding elements, respectively the roof constructions, has been carried out according to the European design norms [1], [5].

Option Panels in Pure-Jump Settings

DEFF Research Database (Denmark)

Andersen, Torben Gustav; Fusari, Nicola; Todorov, Viktor

We develop parametric inference procedures for large panels of noisy option data in the setting where the underlying process is of pure-jump type, i.e., evolve only through a sequence of jumps. The panel consists of options written on the underlying asset with a (different) set of strikes...... specification for the risk-neutral asset return dynamics, the option prices are nonlinear functions of a time-invariant parameter vector and a time-varying latent state vector (or factors). Furthermore, no-arbitrage restrictions impose a direct link between some of the quantities that may be identified from...... the return and option data. These include the so-called jump activity index as well as the time-varying jump intensity. We propose penalized least squares estimation in which we minimize L_2 distance between observed and model-implied options and further penalize for the deviation of model-implied quantities...

Inverse heat transfer analysis of a functionally graded fin to estimate time-dependent base heat flux and temperature distributions

International Nuclear Information System (INIS)

Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih; Yang, Yu-Ching

2012-01-01

Highlights: ► Time-dependent base heat flux of a functionally graded fin is inversely estimated. ► An inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied. ► The distributions of temperature in the fin are determined as well. ► The influence of measurement error and measurement location upon the precision of the estimated results is also investigated. - Abstract: In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to estimate the unknown time-dependent base heat flux of a functionally graded fin from the knowledge of temperature measurements taken within the fin. Subsequently, the distributions of temperature in the fin can be determined as well. It is assumed that no prior information is available on the functional form of the unknown base heat flux; hence the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors and measurement location upon the precision of the estimated results is also investigated. Results show that an excellent estimation on the time-dependent base heat flux and temperature distributions can be obtained for the test case considered in this study.

Complete reconstruction of all annunciator panels and their auxiliary facilities at central regulation office in KURRI

International Nuclear Information System (INIS)

Ishihara, Shinji; Kimura, Yasuhiro; Nakamura, Hiroshi; Nishino, Kunihiko; Higashiyama, Yukihiro; Okamoto, Ken-ichi; Maki, Hirotoshi; Kimura, Itsuro.

1988-08-01

At the Research Reactor Institute of Kyoto University (KURRI) which is a joint research center with Kyoto University Reactor KUR and so forth for nation-wide universities, most of important alarm signals from KUR, KUCA and other radiation facilities are concentrated at the central regulation office. Although the function of this office had been kept normal for more than 20 years, it became necessary to reconstruct all of its annunciator panels in order to add new alarm systems, for example a newly built spent fuel storage building and a newly installed cold neutron source in KUR, and to improve the functions of old alarm systems. Thereupon, all of the annunciator panels of this office together with their auxiliary facilities were completely reconstructed in the fiscal year of 1985. Furthermore the room of this office was enlarged and reconstructed thoroughly, since it was rather narrow and inconvenient before. This report describes the reconstruction work in detail: (1) Function of the central regulation office, (2) Outline of this work, (3) Design concept, (4) Method and special cares, (5) Reconstruction of the room, (6) New utility tunnels for cables, (7) Configulation and structure of new annunciator panels, (8) Cables and their reconnection, (9) Annunciator circuits, (10) Function of each panel, (11) Test and performance, and (12) concluding remarks and future plans. This experience may be useful for the case of reconstruction of the control desk and instrumentation panels of KUR in future. (author)

On the link between oil and commodity prices: a panel VAR approach

International Nuclear Information System (INIS)

Bremond, Vincent; Hache, Emmanuel; Joets, Marc

2013-12-01

The aim of this paper is to study the relationships between the price of oil and a large dataset of commodity prices, relying on panel data settings. Using second generation panel co-integration tests, our findings show that the WTI and commodity prices are not linked in the long term. Nevertheless, considering our results in causality tests, we show that short-run relations exist, mainly from the price of crude oil to commodity prices. We thus implement a panel VAR estimation with an impulse response function analysis. Two main conclusions emerge: (i) fast co-movements are highlighted, while (ii) market efficiency is emphasized. (authors)

78 FR 27971 - Dental Products Panel of the Medical Devices Advisory Committee; Notice of Meeting

Science.gov (United States)

2013-05-13

...] Dental Products Panel of the Medical Devices Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Dental Products Panel of the Medical Devices Advisory Committee. General Function of the Committee: To... regulatory classification for dental devices known as Endosseous Dental Implants (Blade-form), one of the...

78 FR 26786 - Microbiology Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Science.gov (United States)

2013-05-08

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0001] Microbiology Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Microbiology Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To...

76 FR 48871 - Immunology Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Science.gov (United States)

2011-08-09

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2011-N-0002] Immunology Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting AGENCY: Food and Drug...: Immunology Devices Panel of the Medical Devices Advisory Committee. General Function of the Committee: To...

A framework for the computer-aided planning and optimisation of manufacturing processes for components with functional graded properties

Science.gov (United States)

Biermann, D.; Gausemeier, J.; Heim, H.-P.; Hess, S.; Petersen, M.; Ries, A.; Wagner, T.

2014-05-01

In this contribution a framework for the computer-aided planning and optimisation of functional graded components is presented. The framework is divided into three modules - the "Component Description", the "Expert System" for the synthetisation of several process chains and the "Modelling and Process Chain Optimisation". The Component Description module enhances a standard computer-aided design (CAD) model by a voxel-based representation of the graded properties. The Expert System synthesises process steps stored in the knowledge base to generate several alternative process chains. Each process chain is capable of producing components according to the enhanced CAD model and usually consists of a sequence of heating-, cooling-, and forming processes. The dependencies between the component and the applied manufacturing processes as well as between the processes themselves need to be considered. The Expert System utilises an ontology for that purpose. The ontology represents all dependencies in a structured way and connects the information of the knowledge base via relations. The third module performs the evaluation of the generated process chains. To accomplish this, the parameters of each process are optimised with respect to the component specification, whereby the result of the best parameterisation is used as representative value. Finally, the process chain which is capable of manufacturing a functionally graded component in an optimal way regarding to the property distributions of the component description is presented by means of a dedicated specification technique.

COMPARISON OF SIMPLE SUM AND DIVISIA MONETARY AGGREGATES USING PANEL DATA ANALYSIS

Directory of Open Access Journals (Sweden)

Sadullah CELIK

2009-07-01

Full Text Available It is well documented that financial innovation has led to poor performance of simple sum method of monetary aggregation destabilizing the historical relationship between monetary aggregates and ultimate target variables like rate of growth and rate of unemployment during the liberalization period of 1980s. This study tries to emphasize the superiority of an alternative method of aggregation over the simple sum method, namely Divisia monetary aggregates, employing panel data analysis for United States, United Kingdom, Euro Area and Japan for the period between 1980Q1 and 1993Q3. After investigating the order of stationarity of the panel data set through several panel unit root tests, we perform advanced panel cointegration tests to check the existence of a long run link between the Divisia monetary aggregates and income and interest rates in a simple Keynesian money demand function.

Panel Session

DEFF Research Database (Denmark)

Bertelsen, Olav Wedege

2004-01-01

In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach.......In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach....

Modeling of Cooling Channels of Injection Mould using Functionally Graded Material

International Nuclear Information System (INIS)

Shin, Ki Hoon

2011-01-01

The cycle time in injection moulding greatly depends on the cooling time of the plastic part that is controlled by cooling channels. Cooling channels are required to facilitate the heat transfer rate from the die to the coolant without reducing the strength of the die. Employing layered manufacturing techniques (LMT), a die embedding conformal cooling channels can be fabricated directly while conventional cooling channels are usually made of straight drilled hole. Meanwhile, H13 tool steel is widely used as the die material because of its high thermal resistance and dimensional stability. However, H13 with a low thermal conductivity is not efficient for certain part geometries. In this context, the use of functionally graded materials (FGMs) between H13 and copper may circumvent a tradeoff between the strength and the heat transfer rate. This paper presents a method for modeling of conformal cooling channels made of FGMs

Photonically wired spacecraft panels: an economic analysis and demonstrator for telecommunication satellites

Science.gov (United States)

Putzer, Philipp; Hurni, Andreas; Ziegler, Bent; Panopoulou, Aikaterini; Lemke, Norbert; Costa, Ivo; Pereira, Celeste

2017-09-01

In this paper we present the design of smart satellite panels with integrated optical fibers for sensing and data communication. The project starts with a detailed analysis of the system needs and ends with a demonstrator breadboard showing the full performance during and after environmental tests such as vibrations and temperature. Future science missions will need higher bandwidth in the Gbit/s range for intra-satellite communications, so the step from electrical transmission media towards fiber-optical media is the logical next step to cope with future requirements. In addition, the fibers can be used to monitor temperatures directly underneath satellite payloads which will reduce the integration effort in a later phase. For temperature monitoring so called fiber Bragg gratings (FBGs) are written in special radiation tolerant fibers, which reflection wavelength allows a direct link to temperature at the grating position. A read-out system for FBGs to use within satellite applications is currently under development at OHB. For this study, first the environmental requirements for the panels are derived and in a second stage the functional requirements are defined. To define the functional requirements a telecommunication satellite platform, in the case here the Small-GEO series from OHB, has been taken as baseline. Based on the configuration of temperature sensors, communication lines and electrical signaling a possible replacement by fiber-optical technology was defined and traded w.r.t. its economic benefit. It has been pointed out that the replacement of temperature sensors will reduce harness mass, but the great benefit is seen here in the reduction of assembly effort. Once the satellite panel is manufactured, the temperature sensors are already implemented at certain positions. Another point for mass savings which has pointed out is the replacement of the high-voltage or high- current high power commands (HPC) by fiber optics. Replacing some of the several

78 FR 41937 - Joint Meeting of the Gastroenterology-Urology Panel and the Radiological Devices Panel of the...

Science.gov (United States)

2013-07-12

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0816] Joint Meeting of the Gastroenterology-Urology Panel and the Radiological Devices Panel of the Medical...: Gastroenterology-Urology Panel and Radiological Devices Panel of the Medical Devices Advisory Committee. General...

Parametric instability of a functionally graded Timoshenko beam on Winkler's elastic foundation

International Nuclear Information System (INIS)

Mohanty, S.C.; Dash, R.R.; Rout, T.

2011-01-01

Highlights: → Winkler's elastic foundation enhances the stability of both FGO and FGSW beams with material properties distribution along the thickness as per power law and exponential law. → FGO beam with steel-rich bottom is more stable than a beam with aluminium-rich bottom for both the types of property distribution. → FGSW beam with the properties in FGM core varying as per power law becomes less stable with increase in core thickness. → Exponential variation of core properties enhances its stability with the increase in core thickness. - Abstract: This article presents an investigation of the dynamic stability of functionally graded ordinary (FGO) beam and functionally graded sandwich (FGSW) beam on Winkler's elastic foundation using finite element method. The material properties are assumed to follow both exponential and power law. It is found that the foundation enhances stability of the FGO beam for first three modes. The effect of distributions of material properties of the FGO beam on its parametric instability is investigated. It is found that the FGO beam with steel-rich bottom is more stable as compared to that with Al-rich bottom for all the three modes and for both the types of property distributions. The effect of property distribution on stability of FGSW beam with steel as bottom skin and alumina as top skin is also investigated. It is observed that the beam having properties in core according to exponential law is the most stable beam while the beam having properties in core as per power law with index 2.5 is the least stable beam. For an FGSW beam it is found that the increase in the thickness of FGM core makes the beam less stable when the properties in FGM vary as per power law whereas the stability of beam enhances with the increase of thickness of FGM core when the properties vary according to exponential law.

Effect of Thermoelectric Cooling (TEC module and the water flow heatsink on Photovoltaic (PV panel performance

Directory of Open Access Journals (Sweden)

Amelia A.R.

2017-01-01

Full Text Available Photovoltaic (PV panel suffers in low conversion efficiency of the output performance affected by the elevated operating temperature of the PV panel. It is important to keep the PV panel to operate at low temperature. To address this issue, this paper proposes the cooling system using thermoelectric cooling (TEC and water block heatsink for enhancing the PV panel output performance. These both types cooling system were designed located on the back side of the PV panel to cool down the operating temperature of the PV panel. To evaluate the function for the existing cooling systems, the experiment was subsequently performed for PV panel without and with different design of the cooling system in outdoor weather conditions. By comparing the experimental results, it is concluded that by the hybrid cooling system which combining TEC module and the water block heatsink could improve the output performance of the PV panel. By the reduction temperature of the PV panel by 16.04 %, the average output power of the PV panel has been boosted up from 8.59 W to 9.03 W. In short, the output power of the PV panel was enhanced by the reduction of the operating temperature of the PV panel.

Effect of Thermoelectric Cooling (TEC) module and the water flow heatsink on Photovoltaic (PV) panel performance

Science.gov (United States)

Amelia, A. R.; Jusoh, MA; Shamira Idris, Ida

2017-11-01

Photovoltaic (PV) panel suffers in low conversion efficiency of the output performance affected by the elevated operating temperature of the PV panel. It is important to keep the PV panel to operate at low temperature. To address this issue, this paper proposes the cooling system using thermoelectric cooling (TEC) and water block heatsink for enhancing the PV panel output performance. These both types cooling system were designed located on the back side of the PV panel to cool down the operating temperature of the PV panel. To evaluate the function for the existing cooling systems, the experiment was subsequently performed for PV panel without and with different design of the cooling system in outdoor weather conditions. By comparing the experimental results, it is concluded that by the hybrid cooling system which combining TEC module and the water block heatsink could improve the output performance of the PV panel. By the reduction temperature of the PV panel by 16.04 %, the average output power of the PV panel has been boosted up from 8.59 W to 9.03 W. In short, the output power of the PV panel was enhanced by the reduction of the operating temperature of the PV panel.

A Selective Biomarker Panel Increases the Reproducibility and the Accuracy in Endometrial Biopsy Diagnosis

DEFF Research Database (Denmark)

Nastic, Denis; Shanwell, Emma; Wallin, Keng-Ling

2017-01-01

Grading and histologic typing of endometrial cancer in biopsy material has a direct impact on the decision to perform lymphadenectomy and/or omentectomy in many cancer centers. Endometrial biopsies are among the most common general surgical pathology specimens. Multiple studies have shown...... that biopsy diagnosis suffers from a lack of reproducibility. Although many biomarkers have been proposed, none have been demonstrated to improve the diagnosis in the biopsy setting. In this study, 70 biopsies with endometrial carcinoma were supplemented with a biomarker panel consisting of ER, PR, P53...

Boundary values as Hamiltonian variables. II. Graded structures

International Nuclear Information System (INIS)

Soloviev, Vladimir O.

2002-01-01

It is shown that the new formula for the field theory Poisson brackets arises naturally in the proposed extension of the formal variational calculus incorporating divergences. The linear spaces of local functionals, evolutionary vector fields, functional forms, multi-vectors and differential operators become graded with respect to divergences. The bilinear operations, such as the action of vector fields onto functionals, the commutator of vector fields, the interior product of forms and vectors and the Schouten-Nijenhuis bracket are compatible with the grading. A definition of the adjoint graded operator is proposed and antisymmetric operators are constructed with the help of boundary terms. The fulfilment of the Jacobi identity for the new Poisson brackets is shown to be equivalent to vanishing of the Schouten-Nijenhuis bracket of the Poisson bivector with itself

Differential conductivity mapping of solar panels using a high-TC superconductor SQUID

International Nuclear Information System (INIS)

Kiwa, T.; Maeda, S.; Miyake, K.; Kataoka, N.; Tsukamoto, A.; Adachi, S.; Tanabe, K.; Kandori, A.; Tsukada, K.

2011-01-01

To visualise the distribution of the electric property of solar cells, we developed a differential conductivity mapping system using high-T C (HTS-) superconductor SQUID with a normal conducting pick-up coil. The bias ac voltage with an offset voltage was applied to a solar panel made from amorphous silicon, and the normal component of the generated magnetic field was lock-in-detected. Thus the measured signal was converted to dB/dV properties, which are inverse-proportional to the differential resistivity, as the function of the offset voltage. By scanning the pick-up coil across the panel surface, we obtained the distribution of dB/dV properties across the solar panel was obtained by scanning the pick-up coil across the panel surface. The distribution of dB/dV on the panel differed between when the light source was on and when it was off. This result suggests that the proposed system is a potential tool for diagnosing the electric properties of solar cells.

High-grade and low-grade gliomas: differentiation by using perfusion MR imaging

International Nuclear Information System (INIS)

Hakyemez, B.; Erdogan, C.; Ercan, I.; Ergin, N.; Uysal, S.; Atahan, S.

2005-01-01

AIM: Relative cerebral blood volume (rCBV) is a commonly used perfusion magnetic resonance imaging (MRI) technique for the evaluation of tumour grade. Relative cerebral blood flow (rCBF) has been less studied. The goal of our study was to determine the usefulness of these parameters in evaluating the histopathological grade of the cerebral gliomas. METHODS: This study involved 33 patients (22 high-grade and 11 low-grade glioma cases). MRI was performed for all tumours by using a first-passage gadopentetate dimeglumine T2*-weighted gradient-echo single-shot echo-planar sequence followed by conventional MRI. The rCBV and rCBF were calculated by deconvolution of an arterial input function. The rCBV and rCBF ratios of the lesions were obtained by dividing the values obtained from the normal white matter of the contralateral hemisphere. For statistical analysis Mann-Whitney testing was carried out. A p value of less than 0.05 indicated a statistically significant difference. Receiver operating characteristic curve (ROC) analysis was performed to assess the relationship between the rCBV and rCBF ratios and grade of gliomas. Their cut-off value permitting discrimination was calculated. The correlation between rCBV and CBF ratios and glioma grade was assessed using Pearson correlation analysis. RESULTS: In high-grade gliomas, rCBV and rCBF ratios were measured as 6.50±4.29 and 3.32±1.87 (mean±SD), respectively. In low-grade gliomas, rCBV and rCBF ratios were 1.69±0.51 and 1.16±0.38, respectively. The rCBV and rCBF ratios for high-grade gliomas were statistically different from those of low-grade gliomas (p 0.05). The cut-off value was taken as 1.98 in the rCBV ratio and 1.25 in the rCBF ratio. There was a strong correlation between the rCBV and CBF ratios (Pearson correlation = 0.830, p<0.05). CONCLUSION: Perfusion MRI is useful in the preoperative assessment of the histopathologicalal grade of gliomas; the rCBF ratio in addition to the rCBV ratio can be incorporated

Effect of Graded Unilateral Sanding Exercise on Metabolic and Cardiopulmonary Function in the Healthy and the Hemiparetic Elderly Subjects

OpenAIRE

Muraki, Toshiaki

1997-01-01

The purpose of this study was to investigate how 18 elderly subjects with cerebral vascular accident (CVA) (14 men and 4 women) and 19 healthy elderly subjects (6 men and 13 women) would respond to a five-step graded unilateral sanding activity. Three indicators of pulmonary function such as expiratory tidal volume, respiratory rate, and expiratory volume and four indicators of cardiometabolic function such as metabolic equivalents (METS), systolic blood pressure, heart rate, and pressure rat...

Use of Internet panels to conduct surveys.

Science.gov (United States)

Hays, Ron D; Liu, Honghu; Kapteyn, Arie

2015-09-01

The use of Internet panels to collect survey data is increasing because it is cost-effective, enables access to large and diverse samples quickly, takes less time than traditional methods to obtain data for analysis, and the standardization of the data collection process makes studies easy to replicate. A variety of probability-based panels have been created, including Telepanel/CentERpanel, Knowledge Networks (now GFK KnowledgePanel), the American Life Panel, the Longitudinal Internet Studies for the Social Sciences panel, and the Understanding America Study panel. Despite the advantage of having a known denominator (sampling frame), the probability-based Internet panels often have low recruitment participation rates, and some have argued that there is little practical difference between opting out of a probability sample and opting into a nonprobability (convenience) Internet panel. This article provides an overview of both probability-based and convenience panels, discussing potential benefits and cautions for each method, and summarizing the approaches used to weight panel respondents in order to better represent the underlying population. Challenges of using Internet panel data are discussed, including false answers, careless responses, giving the same answer repeatedly, getting multiple surveys from the same respondent, and panelists being members of multiple panels. More is to be learned about Internet panels generally and about Web-based data collection, as well as how to evaluate data collected using mobile devices and social-media platforms.

No correlation between ultrasound placental grading at 31-34 weeks of gestation and a surrogate estimate of organ function at term obtained by stereological analysis.

Science.gov (United States)

Yin, T T; Loughna, P; Ong, S S; Padfield, J; Mayhew, T M

2009-08-01

We test the experimental hypothesis that early changes in the ultrasound appearance of the placenta reflect poor or reduced placental function. The sonographic (Grannum) grade of placental maturity was compared to placental function as expressed by the morphometric oxygen diffusive conductance of the villous membrane. Ultrasonography was used to assess the Grannum grade of 32 placentas at 31-34 weeks of gestation. Indications for the scans included a history of previous fetal abnormalities, previous fetal growth problems or suspicion of IUGR. Placentas were classified from grade 0 (most immature) to grade III (most mature). We did not exclude smokers or complicated pregnancies as we aimed to correlate the early appearance of mature placentas with placental function. After delivery, microscopical fields on formalin-fixed, trichrome-stained histological sections of each placenta were obtained by multistage systematic uniform random sampling. Using design-based stereological methods, the exchange surface areas of peripheral (terminal and intermediate) villi and their fetal capillaries and the arithmetic and harmonic mean thicknesses of the villous membrane (maternal surface of villous trophoblast to adluminal surface of vascular endothelium) were estimated. An index of the variability in thickness of this membrane, and an estimate of its oxygen diffusive conductance, were derived secondarily as were estimates of the mean diameters and total lengths of villi and fetal capillaries. Group comparisons were drawn using analysis of variance. We found no significant differences in placental volume or composition or in the dimensions or diffusive conductances of the villous membrane. Subsequent exclusion of smokers did not alter these main findings. Grannum grades at 31-34 weeks of gestation appear not to provide reliable predictors of the functional capacity of the term placenta as expressed by the surrogate measure, morphometric diffusive conductance.

Micro-inverter solar panel mounting

Science.gov (United States)

Morris, John; Gilchrist, Phillip Charles

2016-02-02

Processes, systems, devices, and articles of manufacture are provided. Each may include adapting micro-inverters initially configured for frame-mounting to mounting on a frameless solar panel. This securement may include using an adaptive clamp or several adaptive clamps secured to a micro-inverter or its components, and using compressive forces applied directly to the solar panel to secure the adaptive clamp and the components to the solar panel. The clamps can also include compressive spacers and safeties for managing the compressive forces exerted on the solar panels. Friction zones may also be used for managing slipping between the clamp and the solar panel during or after installation. Adjustments to the clamps may be carried out through various means and by changing the physical size of the clamps themselves.

1994 Panel 1 Utilization Plan

International Nuclear Information System (INIS)

1994-01-01

The Waste Isolation Pilot Plant (WIPP) is intended to receive, handle, and permanently dispose of transuranic (TRU) waste. To fulfill this mission, the U.S. Department of Energy (DOE) constructed a full-scale facility to demonstrate both technical and operational principles of the permanent isolation of TRU waste. The WIPP consists of surface and underground facilities. Panel 1 is situated in the underground facility horizon which is located approximately 2,150 feet below the surface in the predominantly halite Salado Formation. The Panel 1 Utilization Plan provides a strategy for the optimum use of Panel 1 which is consistent with the priorities established by the DOE to accomplish the WIPP mission. These priorities, which include maintaining personnel safety, conducting performance assessment, and continued operational enhancements, are the guiding premise for the decisions on the planned usage of the WIPP underground facility. The continuation of ongoing investigations along with the planned testing and training to be carried out in Panel 1 will enhance the current knowledge and understanding of the operational and geotechnical aspects of the panel configuration. This enhancement will ultimately lead to safer, more efficient, and more cost-effective methods of operation. Excavation of the waste storage area began in May 1986 with the mining of entries to Panel 1. The original design for the waste storage rooms at the WIPP provided a limited period of time during which to mine the openings and to emplace waste. Each panel, consisting of seven storage rooms, was scheduled to be mined and filled in less than 5 years. Panel 1 was developed to receive waste for a demonstration phase that was scheduled to start in October 1988. The demonstration phase was deferred, and the experimental test program was modified to use contact-handled (CH) transuranic waste in bin-scale tests, planned for Room 1, Panel 1

Processing of W-Cu functionally graded materials (FGM) through the powder metallurgy route: application as plasma facing components for ITER-like thermonuclear fusion reactor

International Nuclear Information System (INIS)

Raharijaona, J.J.

2009-11-01

The aim of this study was to study and optimize the sintering of W-Cu graded composition materials, for first wall of ITER-like thermonuclear reactor application. The graded composition in the material generates graded functional properties (Functionally Graded Materials - FGM). Rough thermomechanical calculations have shown the interest of W-Cu FGM to improve the lifetime of Plasma Facing Components (PFC). To process W-Cu FGM, powder metallurgy route was analyzed and optimized from W-CuO powder mixtures. The influence of oxide reduction on the sintering of powder mixtures was highlighted. An optimal heating treatment under He/H 2 atmosphere was determined. The sintering mechanisms were deduced from the analysis of the effect of the Cu-content. Sintering of W-Cu materials with a graded composition and grain size has revealed two liquid migration steps: i) capillary migration, after the Cu-melting and, ii) expulsion of liquid, at the end of sintering, from the dense part to the porous part, due to the continuation of W-skeleton sintering. These two steps were confirmed by a model based on capillary pressure calculation. In addition, thermal conductivity measurements were conducted on sintered parts and showed values which gradually increase with the Cu-content. Hardness tests on a polished cross-section in the bulk are consistent with the composition profiles obtained and the differential grain size. (author)

Grading and disease management in national screening for diabetic retinopathy in England and Wales.

Science.gov (United States)

Harding, S; Greenwood, R; Aldington, S; Gibson, J; Owens, D; Taylor, R; Kohner, E; Scanlon, P; Leese, G

2003-12-01

A National Screening Programme for diabetic eye disease in the UK is in development. We propose a grading and early disease management protocol to detect sight-threatening diabetic retinopathy and any retinopathy, which will allow precise quality assurance at all steps while minimizing false-positive referral to the hospital eye service. Expert panel structured discussions between 2000 and 2002 with review of existing evidence and grading classifications. Principles of the protocol include: separate grading of retinopathy and maculopathy, minimum number of steps, compatible with central monitoring, expandable for established more complex systems and for research, no lesion counting, no 'questionable' lesions, attempt to detect focal exudative, diffuse and ischaemic maculopathy and fast track referral from primary or secondary graders. Sight-threatening diabetic retinopathy is defined as: preproliferative retinopathy or worse, sight-threatening maculopathy and/or the presence of photocoagulation. In the centrally reported minimum data set retinopathy is graded into four levels: none (R0), background (R1), preproliferative (R2), proliferative (R3). Maculopathy and photocoagulation are graded as absent (M0, P0) or present (M1, P1). The protocol developed by the Diabetic Retinopathy Grading and Disease Management Working Party represents a new consensus upon which national guidelines can be based leading to the introduction of quality-assured screening for people with diabetes.

Infill Panels and the tube connection in timber frames

NARCIS (Netherlands)

Leijten, A.J.M.; Jorissen, A.J.M.; Hoenderkamp, J.C.D.

2012-01-01

In recent years timber infill panels have been proposed for multi-story column-beam frame structures with the aim to substitute the stabilizing function of column-beam moment connections. The preliminary study reported in this paper considers a column-beam timber frame where stability is assured by

Lateral Stiffness of Timber Frames with CLT Infill Panels

NARCIS (Netherlands)

Leijten, A.J.M.; Jorissen, A.J.M.; Hoenderkamp, J.C.D.; Haddad, Y.M.

2011-01-01

In recent years timber infill panels have been proposed for multi-story column-beam frame structures with the aim to substitute the stabilizing function of column-beam moment connections. The preliminary study reported in this paper considers a column-beam timber frame where stability is assured by

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-03-15

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

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

International Nuclear Information System (INIS)

Wang, Zhong-Min; Liu, Yan-Zhuang

2016-01-01

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

Frictionless contact analysis of a functionally graded piezoelectric layered half-plane

International Nuclear Information System (INIS)

Ke Liaoliang; Yang Jie; Kitipornchai, Sritawat; Wang Yuesheng

2008-01-01

This paper investigates the frictionless contact problem of a layered half-plane made of functionally graded piezoelectric material (FGPM) in the plane strain state under the action of a rigid punch whose shape may be flat, triangular or cylindrical. It is assumed that the punch is a perfect electrical insulator with zero electric charge distribution. The electroelastic properties of the FGPM layer vary exponentially along the thickness direction. By using the Fourier integral transform technique, the problem is reduced to a Cauchy singular integral equation which is then numerically solved to determine the contact pressure, contact region, maximum indentation depth, normal stress, electrical potential and electric displacement fields. The stress intensity factor is also given to quantitatively characterize the singularity behavior of the contact pressure at the ends of a flat and triangular punch. Numerical results show that both the material property gradient of the FGPM layer and the punch geometry have a significant influence on the contact performance of the FGPM layered half-plane

Data quality in probability-based online panels: Nonresponse, attrition, and panel conditioning

NARCIS (Netherlands)

Struminskaya, B.; Methodology and statistics for the behavioural and social sciences

2014-01-01

Online panels – surveys administered over the Internet in which persons are asked to complete surveys regularly – offer cost reductions compared to surveys that use more traditional modes of data collection (face-to-face, telephone, and mail). However, some characteristics of online panels may cause

Solar panel truss mounting systems and methods

Energy Technology Data Exchange (ETDEWEB)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2016-06-28

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Solar panel truss mounting systems and methods

Energy Technology Data Exchange (ETDEWEB)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2018-01-30

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Solar panel truss mounting systems and methods

Science.gov (United States)

Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

2015-10-20

An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

Cut-off Grade Optimization for Maximizing the Output Rate

Directory of Open Access Journals (Sweden)

A. Khodayari

2012-12-01

Full Text Available In the open-pit mining, one of the first decisions that must be made in production planning stage, after completing the design of final pit limits, is determining of the processing plant cut-off grade. Since this grade has an essential effect on operations, choosing the optimum cut-off grade is of considerable importance. Different goals may be used for determining optimum cut-off grade. One of these goals may be maximizing the output rate (amount of product per year, which is very important, especially from marketing and market share points of view. Objective of this research is determining the optimum cut-off grade of processing plant in order to maximize output rate. For performing this optimization, an Operations Research (OR model has been developed. The object function of this model is output rate that must be maximized. This model has two operational constraints namely mining and processing restrictions. For solving the model a heuristic method has been developed. Results of research show that the optimum cut-off grade for satisfying pre-stated goal is the balancing grade of mining and processing operations, and maximum production rate is a function of the maximum capacity of processing plant and average grade of ore that according to the above optimum cut-off grade must be sent to the plant.

Graphite/epoxy orthogrid panel fabrication

Science.gov (United States)

Lager, J. R.

1978-01-01

The structural concept considered for a spacecraft body structure is a grid stiffened skin with a skin laminate configuration and the stiffener grid geometry selected to best suit the design requirements. The orthogrid panel developed weighs 0.55 lb/sq ft and resisted an ultimate in-plane shear load of 545 lbf/in. The basic concept of a grid stiffener composite panel is that a relatively thin skin is reinforced with a gridwork of stiffeners so that the overall panel can resist design loads without becoming structurally unstable or being overstressed. The main feature of the orthogrid panel design is that it provides the potential for low cost structural panels when advanced to the production phase. The most innovative part of the fabrication method is the foam/fiberglass stiffener web grid billet fabrication and machining to size.

Acoustically Tailored Composite Rotorcraft Fuselage Panels

Science.gov (United States)

Hambric, Stephen; Shepherd, Micah; Koudela, Kevin; Wess, Denis; Snider, Royce; May, Carl; Kendrick, Phil; Lee, Edward; Cai, Liang-Wu

2015-01-01

A rotorcraft roof sandwich panel has been redesigned to optimize sound power transmission loss (TL) and minimize structure-borne sound for frequencies between 1 and 4 kHz where gear meshing noise from the transmission has the most impact on speech intelligibility. The roof section, framed by a grid of ribs, was originally constructed of a single honeycomb core/composite face sheet panel. The original panel has coincidence frequencies near 700 Hz, leading to poor TL across the frequency range of 1 to 4 kHz. To quiet the panel, the cross section was split into two thinner sandwich subpanels separated by an air gap. The air gap was sized to target the fundamental mass-spring-mass resonance of the double panel system to less than 500 Hz. The panels were designed to withstand structural loading from normal rotorcraft operation, as well as 'man-on-the-roof' static loads experienced during maintenance operations. Thin layers of VHB 9469 viscoelastomer from 3M were also included in the face sheet ply layups, increasing panel damping loss factors from about 0.01 to 0.05. Measurements in the NASA SALT facility show the optimized panel provides 6-11 dB of acoustic transmission loss improvement, and 6-15 dB of structure-borne sound reduction at critical rotorcraft transmission tonal frequencies. Analytic panel TL theory simulates the measured performance quite well. Detailed finite element/boundary element modeling of the baseline panel simulates TL slightly more accurately, and also simulates structure-borne sound well.

Paneling architectural freeform surfaces

KAUST Repository

Eigensatz, Michael; Kilian, Martin; Schiftner, Alexander; Mitra, Niloy J.; Pottmann, Helmut; Pauly, Mark

2010-01-01

with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication

Teacher Centers and Advisory Work. A Panel Discussion.

Science.gov (United States)

Apelman, Maja; And Others

Highlights of a panel discussion on advisory work and how it relates to teacher centers and inservice education programs are contained in this transcript. The role of an advisor in a teacher center is to act as a helper, counselor, confidant, and supportive professional to teachers who seek their services. An important function of the advisor is…

Vibration characteristics of functionally graded carbon nanotube reinforced composite rectangular plates on Pasternak foundation with arbitrary boundary conditions and internal line supports

Science.gov (United States)

Zhong, Rui; Wang, Qingshan; Tang, Jinyuan; Shuai, Cijun; Liang, Qian

2018-02-01

This paper presents the first known vibration characteristics of moderately thick functionally graded carbon nanotube reinforced composite rectangular plates on Pasternak foundation with arbitrary boundary conditions and internal line supports on the basis of the firstorder shear deformation theory. Different distributions of single walled carbon nanotubes (SWCNTs) along the thickness are considered. Uniform and other three kinds of functionally graded distributions of carbon nanotubes along the thickness direction of plates are studied. The solutions carried out using an enhanced Ritz method mainly include the following three points: Firstly, create the Lagrange energy function by the energy principle; Secondly, as the main innovation point, the modified Fourier series are chosen as the basic functions of the admissible functions of the plates to eliminate all the relevant discontinuities of the displacements and their derivatives at the edges; Lastly, solve the natural frequencies as well as the associated mode shapes by means of the Ritz-variational energy method. In this study, the influences of the volume fraction of CNTs, distribution type of CNTs, boundary restrain parameters, location of the internal line supports, foundation coefficients on the natural frequencies and mode shapes of the FG-CNT reinforced composite rectangular plates are presented.

Solar-Panel Dust Accumulation and Cleanings

Science.gov (United States)

2005-01-01

Air-fall dust accumulates on the solar panels of NASA's Mars Exploration Rovers, reducing the amount of sunlight reaching the solar arrays. Pre-launch models predicted steady dust accumulation. However, the rovers have been blessed with occasional wind events that clear significant amounts of dust from the solar panels. This graph shows the effects of those panel-cleaning events on the amount of electricity generated by Spirit's solar panels. The horizontal scale is the number of Martian days (sols) after Spirit's Jan. 4, 2005, (Universal Time) landing on Mars. The vertical scale indicates output from the rover's solar panels as a fraction of the amount produced when the clean panels first opened. Note that the gradual declines are interrupted by occasional sharp increases, such as a dust-cleaning event on sol 420.

Panel fabrication utilizing GaAs solar cells

Science.gov (United States)

Mardesich, N.

1984-01-01

The development of the GaAs solar cells for space applications is described. The activities in the fabrication of GaAs solar panels are outlined. Panels were fabricated while introducing improved quality control, soldering laydown and testing procedures. These panels include LIPS II, San Marco Satellite, and a low concentration panel for Rockwells' evaluation. The panels and their present status are discussed.

Attic Retrofits Using Nail-Base Insulated Panels

Energy Technology Data Exchange (ETDEWEB)

Mallay, David [Home Innovation Research Labs; Kochkin, Vladimir [Home Innovation Research Labs

2018-03-26

This project developed and demonstrated a roof/attic energy retrofit solution using nail-base insulated panels for existing homes where traditional attic insulation approaches are not effective or feasible. Nail-base insulated panels (retrofit panels) consist of rigid foam insulation laminated to one face of a wood structural panel. The prefabricated panels are installed above the existing roof deck during a reroofing effort.

Analysing sensory panel performance in a proficiency test using the PanelCheck software

DEFF Research Database (Denmark)

Tomic, O.; Luciano, G.; Nilsen, A.

2010-01-01

Check software, a workflow is proposed that guides the user through the data analysis process. This allows practitioners and non-statisticians to get an overview over panel performances in a rapid manner without the need to be familiar with details on the statistical methods. Visualisation of data analysis...... results plays an important role as this provides a time saving and efficient way of screening and investigating sensory panel performances. Most of the statistical methods used in this paper are available in the open source software PanelCheck, which may be downloaded and used for free....

Cognitive function after radiotherapy for supratentorial low-grade glioma: A North Central Cancer Treatment Group prospective study

International Nuclear Information System (INIS)

Laack, Nadia N.; Brown, Paul D.; Ivnik, Robert J.; Furth, Alfred F. M.S.; Ballman, Karla V.; Hammack, Julie E.; Arusell, Robert M.; Shaw, Edward G.; Buckner, Jan C.

2005-01-01

Purpose: To evaluate the effects of cranial radiotherapy (RT) on cognitive function in patients with supratentorial low-grade glioma. Methods and Materials: Twenty adult patients with supratentorial low-grade glioma were treated with 50.4 Gy (10 patients) or 64.8 Gy (10 patients) localized RT. The patients then were evaluated with an extensive battery of psychometric tests at baseline (before RT) and at approximately 18-month intervals for as long as 5 years after completing RT. To allow patients to serve as their own controls, cognitive performance was evaluated as change in scores over time. All patients underwent at least two evaluations. Results: Baseline test scores were below average compared with age-specific norms. At the second evaluation, the groups' mean test scores were higher than their initial performances on all psychometric measures, although the improvement was not statistically significant. No changes in cognitive performance were seen during the evaluation period when test scores were analyzed by age, treatment, tumor location, tumor type, or extent of resection. Conclusions: Cognitive function was stable after RT in these patients evaluated prospectively during 3 years of follow-up. Slight improvements in some cognitive areas are consistent with practice effects attributable to increased familiarity with test procedures and content

EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to glycaemic carbohydrates and maintenance of normal brain function (ID 603, 653) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

; attention; memory”. The target population is assumed to be the general population. In the context of the proposed wordings, the Panel assumes that the claimed effects refer to the maintenance of normal brain function. The Panel considers that maintenance of normal brain function is a beneficial...... claims in relation to glycaemic carbohydrates and maintenance of normal brain function. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from Member States or directly from...

Mounting clips for panel installation

Science.gov (United States)

Cavieres, Andres; Al-Haddad, Tristan; Goodman, Joseph; Valdes, Francisco

2017-02-14

An exemplary mounting clip for removably attaching panels to a supporting structure comprises a base, spring locking clips, a lateral flange, a lever flange, and a spring bonding pad. The spring locking clips extend upwardly from the base. The lateral flange extends upwardly from a first side of the base. The lateral flange comprises a slot having an opening configured to receive at least a portion of one of the one or more panels. The lever flange extends outwardly from the lateral flange. The spring bonding flange extends downwardly from the lever flange. At least a portion of the first spring bonding flange comprises a serrated edge for gouging at least a portion of the one or more panels when the one or more panels are attached to the mounting clip to electrically and mechanically couple the one or more panels to the mounting clip.

Determination of loss of efficiency photovoltaic panel function of cleaning; Influencia do acumulo de poeira sobre a eficiencia de um painel fotovoltaico

Energy Technology Data Exchange (ETDEWEB)

Michels, Roger N. [Instituto Federal de Educacao, Ciencia e Tecnologia Catarinense (IFC), Luzerna, SC (Brazil)], E-mail: roger@ifc-videira.edu.br; Gnoatto, Estor; Ferruzzi, Yuri; Kavanagh, Edward [Universidade Tecnologica Federal do Parana (UTFPR), Medianeira, PR (Brazil); Melo, Dirceu de [Instituto Federal de Santa Catarina (IFSC), Chapeco, SC (Brazil)

2010-07-01

The use of photovoltaic panels to generate electricity is growing into a worldwide basis. This generation system has a low efficiency, so it is necessary to know the panels will be used, the load will be fed and factors that may influence the operation and performance. The main factors are: radiation, temperature, angle of installation and level the dirt on the surface of the panel. This study aimed to show the difference in efficiency between two sets of photovoltaic panels, one clean and one dirty, the average difference is 16.26%, thus demonstrating the importance of making regular cleaning of photovoltaic panels, and these data can extended to other types of photovoltaic modules. (author)

ALDS 1978 panel review. [PNL

Energy Technology Data Exchange (ETDEWEB)

Hall, D.L. (ed.)

1979-08-01

Pacific Northwest Laboratory (PNL) is examining the analysis of large data sets (ALDS). After one year's work, a panel was convened to evaluate the project. This document is the permanent record of that panel review. It consists of edited transcripts of presentations made to the panel by the PNL staff, a summary of the responses of the panel to these presentations, and PNL's plans for the development of the ALDS project. The representations of the PNL staff described various aspects of the project and/or the philosophy surrounding the project. Supporting materials appear in appendixes. 20 figures, 4 tables. (RWR)

Advanced solar panel designs

Science.gov (United States)

Ralph, E. L.; Linder, E.

1995-01-01

This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

A Sensitive and Specific Diagnostic Panel to Distinguish Diffuse Astrocytoma from Astrocytosis: Chromosome 7 Gain with Mutant Isocitrate Dehydrogenase 1 and p53

Science.gov (United States)

Camelo-Piragua, Sandra; Jansen, Michael; Ganguly, Aniruddha; Kim, J. ChulMin; Cosper, Arjola K.; Dias-Santagata, Dora; Nutt, Catherine L.; Iafrate, A. John; Louis, David N.

2011-01-01

One of the major challenges of surgical neuropathology is the distinction of diffuse astrocytoma (World Health Organization [WHO] grade II) from astrocytosis. The most commonly used ancillary tool to solve this problem is p53 immunohistochemistry (IHC), but this is neither sensitive nor specific. Isocitrate dehydrogenase 1 (IDH1) mutations are common in lower grade gliomas, with most causing a specific amino acid change (R132H) that can be detected with a monoclonal antibody. IDH2 mutations are rare, but also occur in gliomas. In addition, gains of chromosome 7 are common in gliomas. In this study we assessed the status of p53, IDH1/2 and chromosome 7 to determine the most useful panel to distinguish astrocytoma from astrocytosis. We studied biopsy specimens from 21 WHO grade II diffuse astrocytomas and 20 reactive conditions. The single most sensitive test to identify astrocytoma is fluorescence in situ hybridization (FISH) for chromosome 7 gain (76.2%). The combination of p53 and mutant IDH1 IHC provides a higher sensitivity (71.4%) than either test alone (47.8%); this combination offers a practical initial approach for the surgical pathologist. The best overall sensitivity (95%) is achieved when FISH for chromosome 7 gain is added to the p53-mutant IDH1 IHC panel. PMID:21343879

The estimation of I–V curves of PV panel using manufacturers’ I–V curves and evolutionary strategy

International Nuclear Information System (INIS)

Barukčić, M.; Hederić, Ž.; Špoljarić, Ž.

2014-01-01

Highlights: • The approximation of a I–V curve by two linear and a sigmoid functions is proposed. • The sigmoid function is used to estimate the knee of the I–V curve. • Dependence on irradiance and temperature of sigmoid function parameters is proposed. • The sigmoid function is used to estimate maximum power point (MPP). - Abstract: The method for estimation of I–V curves of photovoltaic (PV) panel by analytic expression is presented in the paper. The problem is defined in the form of an optimization problem. The optimization problem objective is based on data from I–V curves obtained by manufacturers’ or measured I–V curves. In order to estimate PV panel parameters, the optimization problem is solved by using an evolutionary strategy. The proposed method is tested for different PV panel technologies using data sheets. In this method the I–V curve approximation with two linear and a sigmoid function is proposed. The method for estimating the knee of the I–V curve and maximum power point at any irradiance and temperature is proposed

A Bootstrap Cointegration Rank Test for Panels of VAR Models

DEFF Research Database (Denmark)

Callot, Laurent

functions of the individual Cointegrated VARs (CVAR) models. A bootstrap based procedure is used to compute empirical distributions of the trace test statistics for these individual models. From these empirical distributions two panel trace test statistics are constructed. The satisfying small sample...

Aging and low-grade inflammation reduce renal function in middle-aged and older adults in Japan and the USA.

Science.gov (United States)

Costello-White, Reagan; Ryff, Carol D; Coe, Christopher L

2015-08-01

The objective of this study was to investigate the effects of low-grade inflammation on age-related changes in glomerular filtration rate (GFR) in middle-aged and older white Americans, African-Americans, and Japanese adults. Serum creatinine, C-reactive protein (CRP), and interleukin-6 (IL-6) levels were determined for 1570 adult participants in two surveys of aging in the USA and Japan (N = 1188 and 382, respectively). Kidney function declined with age in both countries and was associated with IL-6 and CRP. IL-6 and CRP also influenced the extent of the arithmetic bias when calculating the GFR using the chronic kidney disease epidemiology (CKD-EPI) formula with just serum creatinine. Younger African-Americans initially had the highest GFR but showed a steep age-related decrement that was associated with elevated inflammation. Japanese adults had the lowest average GFR but evinced a large effect of increased inflammatory activity when over 70 years of age. Importantly, our results also indicate that low-grade inflammation is important to consider when evaluating kidney function solely from serum creatinine.

Vibration and buckling of orthotropic functionally graded micro-plates on the basis of a re-modified couple stress theory

Directory of Open Access Journals (Sweden)

Zihao Yang

Full Text Available A microstructure-dependent model for the free vibration and buckling analysis of an orthotropic functionally graded micro-plate was proposed on the basis of a re-modified couple stress theory. The macro- and microscopic anisotropy were simultaneously taken into account by introducing two material length scale parameters. The material attributes were assumed to vary continuously through the thickness direction by a power law. The governing equations and corresponding boundary conditions were derived through Hamilton’s principle. The Navier method was used to calculate the natural frequencies and buckling loads of a simply supported micro-plate. The numerical results indicated that the present model predicts higher natural frequencies and critical buckling loads than the classical model, particular when the geometric size of the micro-plates is comparable to the material length scale parameters, i.e., the scale effect is well represented. The scale effect becomes more noticeable as the material length scale parameters increase, the anisotropy weaken or the power law index increases, and vice versa. Keywords: Free vibration, Buckling, Functionally graded materials, Modified couple stress theory, Scale effect

EFSA NDA Panel (EFSA Panel on Dietetic Product s, Nutrition and Allergies), 2013 . Scientific Opinion on the substantiation of a health claim related to vitamin A and contribution to normal development and function of the immune system pursuant to Article 14 of Regulation (EC) No 1924/2006

DEFF Research Database (Denmark)

Tetens, Inge

of infants and young children (from birth to three years). The Panel concludes that a cause and effect relationship has been established between dietary intake of vitamin A and contribution to normal development and function of the immune system. The following wording reflects the scientific evidence......: “Vitamin A contributes to the normal function of the immune system”. The target population is infants and children up to three years. © European Food Safety Authority, 2013...

Tracking Performance of Upgraded "Polished Panel" Optical Receiver on NASA's 34 Meter Research Antenna

Science.gov (United States)

Vilnrotter, Victor

2013-01-01

There has been considerable interest in developing and demonstrating a hybrid "polished panel" optical receiver concept that would replace the microwave panels on the Deep Space Network's (DSN) 34 meter antennas with highly polished aluminum panels, thus enabling simultaneous opticaland microwave reception. A test setup has been installed on the 34 meter research antenna at DSS-13 (Deep Space Station 13) at NASA's Goldstone Deep Space Communications Complex in California in order to assess the feasibility of this concept. Here we describe the results of a recent effort todramatically reduce the dimensions of the point-spread function (PSF) generated by a custom polished panel, thus enabling improved optical communications performance. The latest results are compared to the previous configuration in terms of quantifiable PSF improvement. In addition, the performance of acquisition and tracking algorithms designed specifically for the polished panel PSF are evaluated and compared, based on data obtained from real-time tracking of planets and bright stars with the 34 meter research antenna at DSS-13.

Housing wealth and US money demand : A panel estimation

NARCIS (Netherlands)

Arnold, I.J.M.; Roelands, S.

2011-01-01

This article estimates a panel model for U.S. money demand using annual state-level data for the period from 1977 to 2008. We incorporate housing wealth in the demand-for-money function and find strong evidence of a relationship between a broad monetary aggregate and housing wealth. This finding is

Mechanical and Thermal Analysis of Classical Functionally Graded Coated Beam

Directory of Open Access Journals (Sweden)

Toudehdehghan Abdolreza

2018-01-01

Full Text Available The governing equation of a classical rectangular coated beam made of two layers subjected to thermal and uniformly distributed mechanical loads are derived by using the principle of virtual displacements and based on Euler-Bernoulli deformation beam theory (EBT. The aim of this paper was to analyze the static behavior of clamped-clamped thin coated beam under thermo-mechanical load using MATLAB. Two models were considered for composite coated. The first model was consisting of ceramic layer as a coated and substrate which was metal (HC model. The second model was consisting of Functionally Graded Material (FGM as a coated layer and metal substrate (FGC model. From the result it was apparent that the superiority of the FGC composite against conventional coated composite has been demonstrated. From the analysis, the stress level throughout the thickness at the interface of the coated beam for the FGC was reduced. Yet, the deflection in return was observed to increase. Therefore, this could cater to various new engineering applications where warrant the utilization of material that has properties that are well-beyond the capabilities of the conventional or yesteryears materials.

Thermal shock resistance behavior of a functionally graded ceramic: Effects of finite cooling rate

Directory of Open Access Journals (Sweden)

Zhihe Jin

2014-01-01

Full Text Available This work presents a semi-analytical model to explore the effects of cooling rate on the thermal shock resistance behavior of a functionally graded ceramic (FGC plate with a periodic array of edge cracks. The FGC is assumed to be a thermally heterogeneous material with constant elastic modulus and Poisson's ratio. The cooling rate applied at the FGC surface is modeled using a linear ramp function. An integral equation method and a closed form asymptotic temperature solution are employed to compute the thermal stress intensity factor (TSIF. The thermal shock residual strength and critical thermal shock of the FGC plate are obtained using the SIF criterion. Thermal shock simulations for an Al2O3/Si3N4 FGC indicate that a finite cooling rate leads to a significantly higher critical thermal shock than that under the sudden cooling condition. The residual strength, however, is relatively insensitive to the cooling rate.

FY 1998 annual summary report on comprehensive development study of high-function flat panel display techniques (second year); 1998 nendo koseino flat panel display gijutsu no sogo kaihatsu kenkyu seika hokokusho. Daininendo

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

This project is aimed at creation of the new world display industry in Shikoku by developing the high-function flat panel display techniques and thereby establishing new techniques which solve the problems involved in, e.g., LEDs, plasma-aided devices and ELs other than liquid crystal devices. For development of emitters using diamond, important results have been obtained for the morphology, and cathode luminescence, Raman and photoluminescence spectra of polycrystalline diamond, synthesized by the vapor-phase process under varying conditions, on the electron radiation characteristics of the emitters. These results have led to clarification of the optimum vapor-phase synthesis conditions for diamond for high-function emitters. The techniques utilizing focused ion beams have also advanced to develop thin polycrystalline diamond films for emitters which correspond to the image elements of quality for television. For electron emitters, a structure prepared by implantation without using a high electrical field is proposed, and the device mechanisms involved are clarified. (NEDO)

Panel acoustic contribution analysis.

Science.gov (United States)

Wu, Sean F; Natarajan, Logesh Kumar

2013-02-01

Formulations are derived to analyze the relative panel acoustic contributions of a vibrating structure. The essence of this analysis is to correlate the acoustic power flow from each panel to the radiated acoustic pressure at any field point. The acoustic power is obtained by integrating the normal component of the surface acoustic intensity, which is the product of the surface acoustic pressure and normal surface velocity reconstructed by using the Helmholtz equation least squares based nearfield acoustical holography, over each panel. The significance of this methodology is that it enables one to analyze and rank relative acoustic contributions of individual panels of a complex vibrating structure to acoustic radiation anywhere in the field based on a single set of the acoustic pressures measured in the near field. Moreover, this approach is valid for both interior and exterior regions. Examples of using this method to analyze and rank the relative acoustic contributions of a scaled vehicle cabin are demonstrated.

Advanced Solar Panel Designs

Science.gov (United States)

Ralph, E. L.; Linder, E. B.

1995-01-01

Solar panel designs that utilize new high-efficiency solar cells and lightweight rigid panel technologies are described. The resulting designs increase the specific power (W/kg) achievable in the near-term and are well suited to meet the demands of higher performance small satellites (smallsats). Advanced solar panel designs have been developed and demonstrated on two NASA SBIR contracts at Applied Solar. The first used 19% efficient, large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells with a lightweight rigid graphite epoxy isogrid substrate configuration. A 1,445 sq cm coupon was fabricated and tested to demonstrate 60 W/kg with a high potential of achieving 80 W/kg. The second panel design used new 22% efficiency, dual-junction GaInP2/GaAs/Ge solar cells combined with a lightweight aluminum core/graphite fiber mesh facesheet substrate. A 1,445 sq cm coupon was fabricated and tested to demonstrate 105 W/kg with the potential of achieving 115 W/kg.

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-02-15

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

Inclusion of Population-specific Reference Panel from India to the 1000 Genomes Phase 3 Panel Improves Imputation Accuracy.

Science.gov (United States)

Ahmad, Meraj; Sinha, Anubhav; Ghosh, Sreya; Kumar, Vikrant; Davila, Sonia; Yajnik, Chittaranjan S; Chandak, Giriraj R

2017-07-27

Imputation is a computational method based on the principle of haplotype sharing allowing enrichment of genome-wide association study datasets. It depends on the haplotype structure of the population and density of the genotype data. The 1000 Genomes Project led to the generation of imputation reference panels which have been used globally. However, recent studies have shown that population-specific panels provide better enrichment of genome-wide variants. We compared the imputation accuracy using 1000 Genomes phase 3 reference panel and a panel generated from genome-wide data on 407 individuals from Western India (WIP). The concordance of imputed variants was cross-checked with next-generation re-sequencing data on a subset of genomic regions. Further, using the genome-wide data from 1880 individuals, we demonstrate that WIP works better than the 1000 Genomes phase 3 panel and when merged with it, significantly improves the imputation accuracy throughout the minor allele frequency range. We also show that imputation using only South Asian component of the 1000 Genomes phase 3 panel works as good as the merged panel, making it computationally less intensive job. Thus, our study stresses that imputation accuracy using 1000 Genomes phase 3 panel can be further improved by including population-specific reference panels from South Asia.

Honeycomb metal panel

International Nuclear Information System (INIS)

1979-01-01

Product constituted by a honeycomb metal panel that can be employed to advantage for manufacturing lagging by sandwiching it between two plane sheets, utilized in particular in the nuclear industry where lagging has to have a very long life strength. The honeycomb metal panel is made of an expanded metal extrusion previously cut so as to form, after additional drawing, a honeycomb structure with square or rectangular cells with a plane surface [fr

Computer-Aided Grading of Lymphangioleiomyomatosis (LAM) using HRCT

Science.gov (United States)

Yao, Jianhua; Avila, Nilo; Dwyer, Andrew; Taveira-DaSilva, Angelo M.; Hathaway, Olanda M.; Moss, Joel

2010-01-01

Lymphangioleiomyomatosis (LAM) is a multisystem disorder associated with proliferation of smooth muscle-like cells, which leads to destruction of lung parenchyma. Subjective grading of LAM on HRCT is imprecise and can be arduous especially in cases with severe involvement. We propose a computer-aided evaluation system that grades LAM involvement based on analysis of lung texture patterns. A committee of support vector machines is employed for classification. The system was tested on 36 patients. The computer grade demonstrates good correlation with subjective radiologist grade (R=0.91, p<0.0001) and pulmonary functional tests (R=0.85, p<0.0001). The grade also provides precise progression assessment of disease over time. PMID:21625320

Exascale Workshop Panel Report Meeting

Energy Technology Data Exchange (ETDEWEB)

Khaleel, Mohammad A.

2010-07-01

The Exascale Review Panel consists of 12 scientists and engineers with experience in various aspects of high-performance computing and its application, development, and management. The Panel hear presentations by several representatives of the workshops and town meetings convened over the past few years to examine the need for exascale computation capability and the justification for a U.S. Department of Energy (DOE) program to develop such capability. This report summarizes information provided by the presenters and substantial written reports to the Panel in advance of the meeting in Washington D.C. on January 19-20, 2010. The report also summarizes the Panel's conclusions with regard to the justification of a DOE-led exascale initiative.

Preparation and characterization of 6-layered functionally graded nickel-alumina (Ni-Al2O3) composites

Science.gov (United States)

Latiff, M. I. A.; Nuruzzaman, D. M.; Basri, S.; Ismail, N. M.; Jamaludin, S. N. S.; Kamaruzaman, F. F.

2018-04-01

The present research study deals with the preparation of 6-layered functionally graded (FG) metal-ceramic composite materials through powder metallurgy technique. Using a cylindrical die-punch set made of steel, the nickel-alumina (Ni-Al2O3) graded composite structure was fabricated. The samples consist of four gradual inter layers of varied nickel composition (80wt.%, 60wt.%, 40wt.%, 20wt.%) sandwiched with pure Ni and Al2O3 powders at the ends (100wt.% and 0wt.% nickel) were fabricated under 30 ton compaction load using a hydraulic press. After that, two-step sintering was carried out at sintering temperature 1200ºC and soaking time 3 hours was maintained in a tube furnace. The properties of the prepared samples were characterized by radial shrinkage, optical microscopy and hardness testing. Results showed that larger shrinkage occurred within the ceramic phase which proves that more porosities were eliminated in the ceramic rich layers. From the microstructural analysis, it was observed that alumina particles are almost uniformly distributed in nickel matrix, so as nickel particles in the ceramic matrix of alumina-dominant layers. From interfacial analyses, it was observed that a smooth transition in microstructure from one layer to the next confirms a good interfacial solid state bonding between metal-ceramic constituents and good compaction process. On the other hand, microhardness test results suggest that there might be increasing percentage of porosities in the graded structure as the ceramic content rises.

Predicted summary of panel discussion on smart instruments

International Nuclear Information System (INIS)

Sorber, R.E.

1991-01-01

The following is a hypothetical account of a panel discussion on Smart Instruments. It enumerates topics that are likely to covered in the actual discussion. A smart instrument may be defined as one that performs smart functions or as one that contains a computer of some sort. Neither definition is perfect. Smart functions might include, but are not limited to: automated data logging (reading, location, time); transfer (downloading) logged data to outside computer; computer assisted, remote calibration; linearity and dead time correction; performance trending; self diagnosis of faults; detector probe recognition; automated beta factor application; and automatic range selection. These smart functions are discussed

The effectiveness of scoliosis screening programs: methods for systematic review and expert panel recommendations formulation

Science.gov (United States)

2013-01-01

Background Literature on scoliosis screening is vast, however because of the observational nature of available data and methodological flaws, data interpretation is often complex, leading to incomplete and sometimes, somewhat misleading conclusions. The need to propose a set of methods for critical appraisal of the literature about scoliosis screening, a comprehensive summary and rating of the available evidence appeared essential. Methods To address these gaps, the study aims were: i) To propose a framework for the assessment of published studies on scoliosis screening effectiveness; ii) To suggest specific questions to be answered on screening effectiveness instead of trying to reach a global position for or against the programs; iii) To contextualize the knowledge through expert panel consultation and meaningful recommendations. The general methodological approach proceeds through the following steps: Elaboration of the conceptual framework; Formulation of the review questions; Identification of the criteria for the review; Selection of the studies; Critical assessment of the studies; Results synthesis; Formulation and grading of recommendations in response to the questions. This plan follows at best GRADE Group (Grades of Recommendation, Assessment, Development and Evaluation) requirements for systematic reviews, assessing quality of evidence and grading the strength of recommendations. Conclusions In this article, the methods developed in support of this work are presented since they may be of some interest for similar reviews in scoliosis and orthopaedic fields. PMID:23883346

Grounds of two positions photovoltaic panels

OpenAIRE

Castán Fortuño, Fernando

2008-01-01

The objective of this Master Thesis is to find the optimum positioning for a two positions photovoltaic panel. Hence, it will be implemented a model in order to optimize the energy of the sun that the photovoltaic panel is receiving by its positioning. Likewise this project will include the comparison with other photovoltaic panel systems as the single position photovoltaics panels. Ultimately, it is also going to be designed a system array for the optimized model of two positions photovoltai...

Orbiter radiator panel solar focusing test

Science.gov (United States)

Howell, H. R.; Rankin, J. G.

1983-01-01

Test data are presented which define the area around the Orbiter radiator panels for which the solar reflections are concentrated to one-sun or more. The concave shape of the panels and their specular silver/Teflon coating causes focusing of the reflected solar energy which could have adverse heating effects on equipment or astronaut extravehicular activity (EVA) in the vicinity of the radiator panels. A room ambient test method was utilized with a one-tenth scale model of the radiator panels.

Error Patterns with Fraction Calculations at Fourth Grade as a Function of Students' Mathematics Achievement Status.

Science.gov (United States)

Schumacher, Robin F; Malone, Amelia S

2017-09-01

The goal of the present study was to describe fraction-calculation errors among 4 th -grade students and determine whether error patterns differed as a function of problem type (addition vs. subtraction; like vs. unlike denominators), orientation (horizontal vs. vertical), or mathematics-achievement status (low- vs. average- vs. high-achieving). We specifically addressed whether mathematics-achievement status was related to students' tendency to operate with whole number bias. We extended this focus by comparing low-performing students' errors in two instructional settings that focused on two different types of fraction understandings: core instruction that focused on part-whole understanding vs. small-group tutoring that focused on magnitude understanding. Results showed students across the sample were more likely to operate with whole number bias on problems with unlike denominators. Students with low or average achievement (who only participated in core instruction) were more likely to operate with whole number bias than students with low achievement who participated in small-group tutoring. We suggest instruction should emphasize magnitude understanding to sufficiently increase fraction understanding for all students in the upper elementary grades.

Mothers' depressive symptoms in infancy and children's adjustment in grade school: The role of children's sustained attention and executive function.

Science.gov (United States)

Wang, Yiji; Dix, Theodore

2017-09-01

On the basis of longitudinal data across 9 years, this study examined the contribution of sustained attention and executive function to the poor cognitive and socioemotional adjustment of school-age children whose mothers had depressive symptoms during the child's infancy. Mothers (N = 1,364) reported depressive symptoms across their child's infancy and early childhood. Maternal sensitivity was observed during laboratory interactions at 36 months. At school entry children's sustained attention and executive function were measured with computer-generated tasks. In third grade, cognitive and socioemotional adjustment was assessed with standardized tests and the reports of fathers and teachers. Using structural equation modeling, findings showed that (a) exposure to mothers' depressive symptoms during the child's infancy, independent of later exposure, uniquely predicted children's poor sustained attention and executive function at school entry; (b) deficits in children's sustained attention and executive function occurred because of depressed mothers' tendencies to display insensitive parenting behavior; and (c) these deficits explained in part relations between exposure to mothers' depressive symptoms in infancy and children's poor cognitive and socioemotional adjustment in third grade. Findings highlight the potential importance of children's exposure to mothers' depressive symptoms specifically during the child's infancy for disrupting the development of fundamental cognitive processes that may underlie the adjustment problems children of depressed mothers display in middle childhood. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Pull-in behavior analysis of vibrating functionally graded micro-cantilevers under suddenly DC voltage

Directory of Open Access Journals (Sweden)

Jamal Zare

2015-01-01

Full Text Available The present research attempts to explain dynamic pull-in instability of functionally graded micro-cantilevers actuated by step DC voltage while the fringing-field effect is taken into account in the vibrational equation of motion. By employing modern asymptotic approach namely Homotopy Perturbation Method with an auxiliary term, high-order frequency-amplitude relation is obtained, then the influences of material properties and actuation voltage on dynamic pull-in behavior are investigated. It is demonstrated that the auxiliary term in the homotopy perturbation method is extremely effective for higher order approximation and two terms in series expansions are sufficient to produce an acceptable solution. The strength of this analytical procedure is verified through comparison with numerical results.

Analyzing panel acoustic contributions toward the sound field inside the passenger compartment of a full-size automobile.

Science.gov (United States)

Wu, Sean F; Moondra, Manmohan; Beniwal, Ravi

2015-04-01

The Helmholtz equation least squares (HELS)-based nearfield acoustical holography (NAH) is utilized to analyze panel acoustic contributions toward the acoustic field inside the interior region of an automobile. Specifically, the acoustic power flows from individual panels are reconstructed, and relative contributions to sound pressure level and spectrum at any point of interest are calculated. Results demonstrate that by correlating the acoustic power flows from individual panels to the field acoustic pressure, one can correctly locate the panel allowing the most acoustic energy transmission into the vehicle interior. The panel on which the surface acoustic pressure amplitude is the highest should not be used as indicative of the panel responsible for the sound field in the vehicle passenger compartment. Another significant advantage of this HELS-based NAH is that measurements of the input data only need to be taken once by using a conformal array of microphones in the near field, and ranking of panel acoustic contributions to any field point can be readily performed. The transfer functions between individual panels of any vibrating structure to the acoustic pressure anywhere in space are calculated not measured, thus significantly reducing the time and effort involved in panel acoustic contributions analyses.

Relationship between red wine grades and phenolics. 1. Tannin and total phenolics concentrations.

Science.gov (United States)

Mercurio, Meagan D; Dambergs, Robert G; Cozzolino, Daniel; Herderich, Markus J; Smith, Paul A

2010-12-08

Measuring chemical composition is a common approach to support decisions about allocating foods and beverages to grades related to market value. Red wine is a particularly complex beverage, and multiple compositional attributes are needed to account for its sensory properties, including measurement of key phenolic components such as anthocyanins, total phenolics, and tannin, which are related to color and astringency. Color has been shown to relate positively to red wine grade; however, little research has been presented that explores the relationship between astringency-related components such as total phenolic or tannin concentration and wine grade. The aim of this research has been to investigate the relationship between the wine grade allocations of commercial wineries and total phenolic and tannin concentrations, respectively, in Australian Shiraz and Cabernet Sauvignon wines. Total phenolic and tannin concentrations were determined using the methyl cellulose precipitable (MCP) tannin assay and then compared to wine grade allocations made by winemaker panels during the companies' postvintage allocation process. Data were collected from wines produced by one Australian wine company over the 2005, 2006, and 2007 vintages and by a further two companies in 2007 (total wines = 1643). Statistical analysis revealed a positive trend toward higher wine grade allocation and wines that had higher concentrations of both total phenolics and tannin, respectively. This research demonstrates that for these companies, in general, Cabernet Sauvignon and Shiraz wines allocated to higher market value grades have higher total phenolics and higher tannin concentrations and suggests that these compositional parameters should be considered in the development of future multiparameter decision support systems for relevant commercial red wine grading processes. In addition, both tannin and total phenolics would ideally be included because although, in general, a positive relationship

FEMA DFIRM Panel Scheme Polygons

Data.gov (United States)

Minnesota Department of Natural Resources — This layer contains information about the Flood Insurance Rate Map (FIRM) panel areas. The spatial entities representing FIRM panels are polygons. The polygon for...

21 CFR 516.141 - Qualified expert panels.

Science.gov (United States)

2010-04-01

... choose members for the qualified expert panel in accordance with selection criteria listed in paragraph... whether the proposed qualified expert panel meets the selection criteria prior to the panel beginning its... Committee Act, as amended, 5 U.S.C. App. (b) Criteria for the selection of a qualified expert panel. (1) A...

High temperature structural sandwich panels

Science.gov (United States)

Papakonstantinou, Christos G.

High strength composites are being used for making lightweight structural panels that are being employed in aerospace, naval and automotive structures. Recently, there is renewed interest in use of these panels. The major problem of most commercial available sandwich panels is the fire resistance. A recently developed inorganic matrix is investigated for use in cases where fire and high temperature resistance are necessary. The focus of this dissertation is the development of a fireproof composite structural system. Sandwich panels made with polysialate matrices have an excellent potential for use in applications where exposure to high temperatures or fire is a concern. Commercial available sandwich panels will soften and lose nearly all of their compressive strength temperatures lower than 400°C. This dissertation consists of the state of the art, the experimental investigation and the analytical modeling. The state of the art covers the performance of existing high temperature composites, sandwich panels and reinforced concrete beams strengthened with Fiber Reinforced Polymers (FRP). The experimental part consists of four major components: (i) Development of a fireproof syntactic foam with maximum specific strength, (ii) Development of a lightweight syntactic foam based on polystyrene spheres, (iii) Development of the composite system for the skins. The variables are the skin thickness, modulus of elasticity of skin and high temperature resistance, and (iv) Experimental evaluation of the flexural behavior of sandwich panels. Analytical modeling consists of a model for the flexural behavior of lightweight sandwich panels, and a model for deflection calculations of reinforced concrete beams strengthened with FRP subjected to fatigue loading. The experimental and analytical results show that sandwich panels made with polysialate matrices and ceramic spheres do not lose their load bearing capability during severe fire exposure, where temperatures reach several

Molecular Triage of Premalignant Lesions in Liquid-Based Cervical Cytology and Circulating Cell-Free DNA from Urine, Using a Panel of Methylated Human Papilloma Virus and Host Genes

NARCIS (Netherlands)

Guerrero-Preston, Rafael; Valle, Blanca L.; Jedlicka, Anne; Turaga, Nitesh; Folawiyo, Oluwasina; Pirini, Francesca; Lawson, Fahcina; Vergura, Angelo; Noordhuis, Maartje; Dziedzic, Amanda; Perez, Gabriela; Renehan, Marisa; Guerrero-Diaz, Carolina; Rodriguez, Edgar De Jesus; Diaz-Montes, Teresa; Orengo, Jose Rodriguez; Mendez, Keimari; Romaguera, Josefina; Trock, Bruce J.; Florea, Liliana; Sidransky, David

2016-01-01

Clinically useful molecular tools to triage women for a biopsy upon referral to colposcopy are not available. We aimed to develop a molecular panel to detect cervical intraepithelial neoplasia (CIN) grade 2 or higher lesions (CIN2(+)) in women with abnormal cervical cytology and high-risk HPV

Reliability Study in Solar Panels

OpenAIRE

Español Lifante, Albert

2012-01-01

Crystalline silicon Modules are formed by single silicon photovoltaic cells. Since each one of these cells individually contributes to the overall electric power of the panel, the failure of one of them directly affects to its benefits and performance. To Minimize these negative effects, junction boxes with few bypass diodes are usually included in Photovoltaic Solar panels. A still experimental way to built solar panels is to integrate bypass diodes in every single cell, which would in...

Dynamic Contrast-Enhanced Perfusion MRI of High Grade Brain Gliomas Obtained with Arterial or Venous Waveform Input Function.

Science.gov (United States)

Filice, Silvano; Crisi, Girolamo

2016-01-01

The aim of this study was to evaluate the differences in dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) perfusion estimates of high-grade brain gliomas (HGG) due to the use of an input function (IF) obtained respectively from arterial (AIF) and venous (VIF) approaches by two different commercially available software applications. This prospective study includes 20 patients with pathologically confirmed diagnosis of high-grade gliomas. The data source was processed by using two DCE dedicated commercial packages, both based on the extended Toft model, but the first customized to obtain input function from arterial measurement and the second from sagittal sinus sampling. The quantitative parametric perfusion maps estimated from the two software packages were compared by means of a region of interest (ROI) analysis. The resulting input functions from venous and arterial data were also compared. No significant difference has been found between the perfusion parameters obtained with the two different software packages (P-value < .05). The comparison of the VIFs and AIFs obtained by the two packages showed no statistical differences. Direct comparison of DCE-MRI measurements with IF generated by means of arterial or venous waveform led to no statistical difference in quantitative metrics for evaluating HGG. However, additional research involving DCE-MRI acquisition protocols and post-processing would be beneficial to further substantiate the effectiveness of venous approach as the IF method compared with arterial-based IF measurement. Copyright © 2015 by the American Society of Neuroimaging.

STRUCTURAL OPTIMIZATION OF FUNCTIONALLY GRADED MATERIALS WITH SMALL CONCENTRATION OF INCLUSIONS

Directory of Open Access Journals (Sweden)

DISKOVSKY A. A.

2017-01-01

Full Text Available Raising of problem.With an optimal design of inner structure of functionally graded material (FGM based on the classical method of homogenization procedure, in cases of low concentration of inclusions, when the size of inclusions is essentially less than the distance between them, leads to computational difficulties. Purpose – the research to develop a homogenization procedure, allowing solving effectively the problem of optimizing the internal structure of FGM at low concentrations of inclusions and illustration with specific examples. Conclusion. The proposed method allows solving tasks of calculation and optimal design of the internal structure of FGM structures with variable inclusions and with a variable step between them using the same methodology. The optimization is performed using two mechanisms. The first allocation is fixed at the edges of the border areas in which inclusions are absent. The second optimization mechanism is the distribution of inclusions sizes under the law, coinciding with the distribution law of an external load. Alternate step for the step should be reduced in areas with greater intensity of the external load.

Sound transmission loss of composite sandwich panels

Science.gov (United States)

Zhou, Ran

Light composite sandwich panels are increasingly used in automobiles, ships and aircraft, because of the advantages they offer of high strength-to-weight ratios. However, the acoustical properties of these light and stiff structures can be less desirable than those of equivalent metal panels. These undesirable properties can lead to high interior noise levels. A number of researchers have studied the acoustical properties of honeycomb and foam sandwich panels. Not much work, however, has been carried out on foam-filled honeycomb sandwich panels. In this dissertation, governing equations for the forced vibration of asymmetric sandwich panels are developed. An analytical expression for modal densities of symmetric sandwich panels is derived from a sixth-order governing equation. A boundary element analysis model for the sound transmission loss of symmetric sandwich panels is proposed. Measurements of the modal density, total loss factor, radiation loss factor, and sound transmission loss of foam-filled honeycomb sandwich panels with different configurations and thicknesses are presented. Comparisons between the predicted sound transmission loss values obtained from wave impedance analysis, statistical energy analysis, boundary element analysis, and experimental values are presented. The wave impedance analysis model provides accurate predictions of sound transmission loss for the thin foam-filled honeycomb sandwich panels at frequencies above their first resonance frequencies. The predictions from the statistical energy analysis model are in better agreement with the experimental transmission loss values of the sandwich panels when the measured radiation loss factor values near coincidence are used instead of the theoretical values for single-layer panels. The proposed boundary element analysis model provides more accurate predictions of sound transmission loss for the thick foam-filled honeycomb sandwich panels than either the wave impedance analysis model or the

Suppression of panel flutter of near-space aircraft based on non-probabilistic reliability theory

Directory of Open Access Journals (Sweden)

Ye-Wei Zhang

2016-03-01

Full Text Available The vibration active control of the composite panels with the uncertain parameters in the hypersonic flow is studied using the non-probabilistic reliability theory. Using the piezoelectric patches as active control actuators, dynamic equations of panel are established by finite element method and Hamilton’s principle. And the control model of panel with uncertain parameters is obtained. According to the non-probabilistic reliability index, and besides being based on H∞ robust control theory and non-probabilistic reliability theory, the non-probabilistic reliability performance function is given. Moreover, the relationships between the robust controller and H∞ performance index and reliability are established. Numerical results show that the control method under the influence of reliability, H∞ performance index, and approaching velocity is effective to the vibration suppression of panel in the whole interval of uncertain parameters.

75 FR 82376 - North American Free Trade Agreement, Article 1904 NAFTA Panel Reviews; Request for Panel Review

Science.gov (United States)

2010-12-30

... Mexico and the People's Republic of China. This determination was published in the Federal Register (75... Panel Review. SUMMARY: On December 22, 2010, the Government of Mexico filed a First Request for Panel... Government of Mexico established Rules of Procedure for Article 1904 Binational Panel Reviews (``Rules...

Development of Electrostatically Clean Solar Array Panels

Science.gov (United States)

Stern, Theodore G.

2000-01-01

Certain missions require Electrostatically Clean Solar Array (ECSA) panels to establish a favorable environment for the operation of sensitive scientific instruments. The objective of this program was to demonstrate the feasibility of an ECSA panel that minimizes panel surface potential below 100mV in LEO and GEO charged particle environments, prevents exposure of solar cell voltage and panel insulating surfaces to the ambient environment, and provides an equipotential, grounded structure surrounding the entire panel. An ECSA panel design was developed that uses a Front Side Aperture-Shield (FSA) that covers all inter-cell areas with a single graphite composite laminate, composite edge clips for connecting the FSA to the panel substrate, and built-in tabs that interconnect the FSA to conductive coated coverglasses using a conductive adhesive. Analysis indicated the ability of the design to meet the ECSA requirements. Qualification coupons and a 0.5m x 0.5m prototype panel were fabricated and tested for photovoltaic performance and electrical grounding before and after exposure to acoustic and thermal cycling environments. The results show the feasibility of achieving electrostatic cleanliness with a small penalty in mass, photovoltaic performance and cost, with a design is structurally robust and compatible with a wide range of current solar panel technologies.

Solar panel foundation device

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.W.

1983-03-29

A transportable solar panel foundation device which has a bottom member, at least one upstanding side member, and an essentially open top. The side members are angled to permit nesting of a plurality of the foundation devices, and reinforcement pads are carried by the foundation device to support legs for one or more solar panels.

Law Panel in action.

Science.gov (United States)

Odulana, J

In September 1976 the Africa Regional Council (ARC) of IPPF created a Law Panel to 1) advise the ARC on the emphasis of laws and parenthood programs in the region, 2) investigate legal obstacles to family planning and ways of removing them, 3) institute a monitoring service on laws and court decisions affecting planned parenthood, and 4) prepare a list of lawyers and legal reformers by country. The panel has 1) recommended adoption of an IPPF Central Medical Committee and Central Law Panel statement on sterilization, adolescent fertility control, and the use of medical and auxiliary personnel in family planning services with guidelines for Africa; 2) appointed National Legal Correspondents to carry on the monitoring service mentioned above in 18 countries; and 3) discussed solutions to problems in delivering family planning services with family planning associations in Tanzania, Zambia, Mauritius, Madagascar, and Kenya. Laws governing family planning education and services, marriage, divorce, and maternity benefits in these countries are summarized. In 1978 the panel will hold 2 workshops on law and the status of women.

PVT Panels. Fully renewable and competitive

International Nuclear Information System (INIS)

Bakker, M.; Strootman, K.J.; Jong, M.J.M.

2003-10-01

A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. PVT panels generate more solar energy per unit surface area than a combination of separate PV panels and solar thermal collectors, and share the aesthetic advantage of PV. After several years of research, PVT panels have been developed into a product that is now ready for market introduction. One of the most promising system concepts, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS, and has been found to be able to fully cover both the building related electricity and heat consumption, while keeping the long-term average ground temperature constant. The cost and payback time of such a system have been determined; it has been found that the payback time of this system is approximately two-thirds of the payback time of an identical system but with 21 m 2 of PV panels and 4 m 2 of solar thermal collectors. Finally, by looking at the expected growth in the PV and solar thermal collector market, the market potential for for PVT panels has been found to be very large

Proposed method for determining the thickness of glass in solar collector panels

Science.gov (United States)

Moore, D. M.

1980-01-01

An analytical method was developed for determining the minimum thickness for simply supported, rectangular glass plates subjected to uniform normal pressure environmental loads such as wind, earthquake, snow, and deadweight. The method consists of comparing an analytical prediction of the stress in the glass panel to a glass breakage stress determined from fracture mechanics considerations. Based on extensive analysis using the nonlinear finite element structural analysis program ARGUS, design curves for the structural analysis of simply supported rectangular plates were developed. These curves yield the center deflection, center stress and corner stress as a function of a dimensionless parameter describing the load intensity. A method of estimating the glass breakage stress as a function of a specified failure rate, degree of glass temper, design life, load duration time, and panel size is also presented.

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

Directory of Open Access Journals (Sweden)

Hee-Jong Choi

2011-12-01

Full Text Available In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 (CB=0.60 hull and KRISO container ship (KCS, a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI. The computational results were validated by comparing with the existing experimental data.

Panel cutting method: new approach to generate panels on a hull in Rankine source potential approximation

Science.gov (United States)

Choi, Hee-Jong; Chun, Ho-Hwan; Park, Il-Ryong; Kim, Jin

2011-12-01

In the present study, a new hull panel generation algorithm, namely panel cutting method, was developed to predict flow phenomena around a ship using the Rankine source potential based panel method, where the iterative method was used to satisfy the nonlinear free surface condition and the trim and sinkage of the ship was taken into account. Numerical computations were performed to investigate the validity of the proposed hull panel generation algorithm for Series 60 (CB=0.60) hull and KRISO container ship (KCS), a container ship designed by Maritime and Ocean Engineering Research Institute (MOERI). The computational results were validated by comparing with the existing experimental data.

[Chronic low-grade inflammation, lipid risk factors and mortality in functionally dependent elderly].

Science.gov (United States)

Vasović, Olga; Trifunović, Danijela; Despotovié, Nebojsa; Milosević, Dragoslav P

2010-07-01

It has been proved that a highly sensitive C-reactive protein (hsCRP) can be used as an established marker of chronic inflammation for cardiovascular risk assessment. Since mean values of both low-density cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) decrease during aging, the knowledge that increased hsCRP concentration predicts mortality (Mt) would influence therapy and treatment outcome. The aim of this study was to examine importance of chronic low grade inflammation and its association with lipid risk factors for all-cause Mt in functionally dependent elderly. The participants of this longitudinal prospective study were 257 functionally dependent elderly aged 65-99 years. Baseline measurements: anthropometric measurements, blood pressure, fasting plasma total cholesterol (TC), triglyceride (TG), HDL-C, LDL-C, non-HDL-C, hemoglobin Alc (HbA1c) were recorded and different lipid ratios were calculated. Inflammation was assessed by the levels of white blood cells, fibrinogen and hsCRP. The participants with hsCRP grater than 10 mg/L were excluded from the study. The residual participants (77.4% women) were divided into three groups according to their hsCRP levels: a low (agressive lipid lowering treatment.

Additive manufacturing of a functionally graded material from Ti-6Al-4V to Invar: Experimental characterization and thermodynamic calculations

International Nuclear Information System (INIS)

Bobbio, Lourdes D.; Otis, Richard A.; Borgonia, John Paul; Dillon, R. Peter; Shapiro, Andrew A.; Liu, Zi-Kui; Beese, Allison M.

2017-01-01

In functionally graded materials (FGMs), the elemental composition, or structure, within a component varies gradually as a function of position, allowing for the gradual transition from one alloy to another, and the local tailoring of properties. One method for fabricating FGMs with varying elemental composition is through layer-by-layer directed energy deposition additive manufacturing. This work combines experimental characterization and computational analysis to investigate a material graded from Ti-6Al-4V to Invar 36 (64 wt% Fe, 36 wt% Ni). The microstructure, composition, phases, and microhardness were determined as a function of position within the FGM. During the fabrication process, detrimental phases associated with the compositional blending of the Ti-6Al-4V and Invar formed, leading to cracking in the final deposited part. Intermetallic phases (FeTi, Fe_2Ti, Ni_3Ti, and NiTi_2) were experimentally identified to occur throughout the gradient region, and were considered as the reason that the FGM cracked during fabrication. CALPHAD (CALculation of PHase Diagrams) thermodynamic calculations were used concurrently to predict phases that would form during the manufacturing process and were compared to the experimental results. The experimental-computational approach described herein for characterizing FGMs can be used to improve the understanding and design of other FGMs.

Orientation of Al3Ti platelets in Al-Al3Ti functionally graded material manufactured by centrifugal method

International Nuclear Information System (INIS)

Watanabe, Y.; Fukui, Y.

1997-01-01

Al-Al 3 Ti functionally graded materials (FGMs) were manufactured by the centrifugal method with a commercial ingot of Al-5 mass% Ti master alloy. The alloy was melted at a liquid/solid coexisting temperature, at which Al 3 Ti remains as a solid, and then it was cast into a thick-walled ring. It was found that the Al-Al 3 Ti functionally graded material can be successfully fabricated by the centrifugal method. It was also found that the volume fraction of the Al 3 Ti can be increased by repetition of the centrifugal method. Since the shape of Al 3 Ti particles in a commercial alloy ingot is that of a platelet, the Al 3 Ti particles are arranged with their platelet planes nearly perpendicular to the radial direction. The orientation effects become stronger when the G number becomes larger. Although the final centrifugal casting was conducted under a very large centrifugal force for the specimen cast three times, the orientation effects were weaker than those in the specimen cast one time. From these observations, it is concluded that the origin of orientation of Al 3 Ti platelets can be attributed to the angular velocity gradient of the melt along the radial direction produced by the difference in the viscosity. (orig.)

Mechanical evaluation with fe analysis of sandwich panels for wind turbine blade

Energy Technology Data Exchange (ETDEWEB)

Yasaswi, M.; Naveen, P.N.E.; Prasad, R.V. [GIET. Dept. of Mechanical Engineering, Rajahmundry (India)

2012-07-01

Sandwich panels are notable for their structural efficiency and are used as load bearing components in various branches of engineering, especially in aerospace and marine industries. The objective of the present work is to perform computer-aided analysis on sandwich panels. The analysis of sandwich panel with truss core are compared with other four types of sandwich panel with continuous corrugated core, top hat core, zed core and channel core. The basic reason to use sandwich structure is to save weight, however smooth skins and excellent fatigue resistance are also attributes of a sandwich structure. A sandwich is comprised of two layered composite materials formed by bonding two or more thin facings or face sheets to relatively thick core materials. In this type of construction the facings resist nearly all of the in-plane loads and out-of-plane bending moments. The thin facings provide nearly all of the bending stiffness because they are generally of a much higher modulus material is located at a greatest distance from the neutral axis of the component. The basic concept of sandwich panel is that the facings carry the bending loads and the core carries the shear loads. The main function of the core material is to distribute local loads and stresses over large areas. From all this analysis it is concluded that the truss core Sandwich panels can be used in wind turbine blade design. (Author)

Modelado y simulación de un panel fotovoltaico empleando técnicas de inteligencia artificial; Modeling and simulation of a photovoltaic panel using artificial intelligence techniques

Directory of Open Access Journals (Sweden)

Adalberto Ospino Castro

2015-04-01

Full Text Available El trabajo presenta la modelación del comportamiento energético y la determinación de los parámetros del circuito equivalente de un panel fotovoltaico con el empleo de técnicas de inteligencia artificial. Para tal efecto, se desarrolló en Matlab un algoritmo genético que permite obtener los parámetros físicos no brindados por los fabricantes para la implementación de funciones matemáticas que se homologuen al comportamiento dinámico de un panel solar. El algoritmo desarrollado en Matlab permite determinar, además, la eficiencia del algoritmo seguidor del punto de máxima potencia del inversor, el cual es un parámetro de no simple obtención o no determinado en condiciones de campo. Finalmente, el algoritmo se probó satisfactoriamente en un panel solar monocristalino de 50W obteniendo adecuados resultados en comparación con el modelo experimental para diferentes niveles de irradiación solar. Los resultados demuestran que el proceso desarrollado constituye una herramienta que puede ser aplicada a paneles fotovoltaicos en condiciones de campo. The paper presents the modeling of the energy behavior and determination of equivalent circuit parameters for a photovoltaic panel using artificial intelligence techniques. For this purpose, it was performed a genetic algorithm in Matlab, which calculates the physical parameters not provided by manufacturers to implement mathematical functions that approve the dynamic behavior of a solar panel. In addition, the algorithm can determine the efficiency of the maximum power point tracking algorithm of the inverter, which is a parameter of not simple obtaining or not determined under field conditions. Finally, the algorithm was successfully tested in a monocrystalline solar 50W panel with excellent results, compared to the experimental model for different levels of solar irradiation. The results demonstrate that the developed process is a tool that can be applied to photovoltaic panels under

Solar panel assembly and support pad

Energy Technology Data Exchange (ETDEWEB)

Hawley, W.W.

1980-10-07

A solar panel assembly is described comprising at least one solar panel, support means for carrying said panel, and at least one support pad having a base plate, upstanding longitudinal sides, and spaced apart flange means for connection to said support means, said upstanding sides and opposed flange means defining an interior volume for receiving and holding weighting material.

Processing and Characterization of Functionally Graded Aluminum (A319)—SiCp Metallic Composites by Centrifugal Casting Technique

Science.gov (United States)

Jayakumar, E.; Jacob, Jibin C.; Rajan, T. P. D.; Joseph, M. A.; Pai, B. C.

2016-08-01

Functionally graded materials (FGM) are successfully adopted for the design and fabrication of engineering components with location-specific properties. The present study describes the processing and characterization of A319 Aluminum functionally graded metal matrix composites (FGMMC) with 10 and 15 wt pct SiCp reinforcements. The liquid stir casting method is used for composite melt preparation followed by FGMMC formation by vertical centrifugal casting method. The process parameters used are the mold preheating temperature of 523 K (250 °C), melt pouring temperature of 1013 K (740 °C), and mold rotation speed of 1300 rpm. The study analyzes the distribution and concentration of reinforcement particles in the radial direction of the FGMMC disk along with the effects of gradation on density, hardness, mechanical strength, the variation in coefficient of thermal expansion and the wear resistance properties at different zones. Microstructures of FGMMC reveal an outward radial gradient distribution of reinforcements forming different zones. Namely, matrix-rich inner, transition, particles-rich outer, and chill zone of a few millimeters thick at the outer most periphery of the casting are formed. From 10-FGM, a radial shift in the position of SiCp maxima is observed in 15-FGM casting. The mechanical characterization depicts enhanced properties for the particle-rich zone. The hardness shows a graded nature in correlation with particle concentration and a maximum of 94.4 HRB has been obtained at the particle-rich region of 15-FGM. In the particle-rich zone, the lowest CTE value of 20.1 µm/mK is also observed with a compressive strength of 650 MPa and an ultimate tensile strength of 279 MPa. The wear resistance is higher at the particle-rich zone of the FGMMC.

Front panel human interface for FASTBUS

International Nuclear Information System (INIS)

Gustavson, D.B.; Holmes, T.L.; Paffrath, L.; Steffani, J.P.

1980-01-01

A human interface based on the Snoop diagnostic module has been designed to facilitate checkout of FASTBUS devices, diagnosis of system faults, and monitoring of system performance. This system, which is a generalization of the usual computer front panel or control console, includes logic analyzer functions, display and manual-control access to other modules, a microprocessor which allows the user to create and execute diagnostic programs and store them on a minifloppy disk, and a diagnostic network which allows remote console operation and coordination of information from multiple segments' Snoops

JERAMI SEBAGAI BAHAN BAKU PANEL AKUSTIK PELAPIS DINDING

Directory of Open Access Journals (Sweden)

Christina E. Mediastika

2008-01-01

Full Text Available The demand of walling panels with acoustic qualification has surprisingly increased, due to the needs for home theaters and mini recording studios in the increase of environmental noise. Therefore, good supply of acoustic panels, especially those with lower price are necessary. A series of study to explore possibility in using paddy-straw as main material to construct cheap and high quality panels has been developed. Prior to this study, an earlier small research showed there was a great potency in using paddy-straw as panels, especially ones drawn from paddy in type IR. The earlier study recommends further research to examine strength of compression and tensile of the constructed panels to go for building materials, which is presented in this paper. Acoustic qualification of the panels is subject for further reserach. Abstract in Bahasa Indonesia: Kebutuhan akan panel pelapis dinding yang bersifat akustik terus meningkat seiring meningkatnya kebisingan dan kebutuhan terhadap ruang studio pribadi. Ketersediaan panel pelapis dinding dengan harga yang lebih terjangkau seperti yang terbuat dari bahan limbah sangatlah dibutuhkan. Pada penelitian awal telah diselidiki kemungkinan penggunaan jerami yang merupakan limbah sebagai bahan baku pembuatan panel akustik. Penelitian tersebut menunjukkan bahwa jerami sangat potensial digunakan sebagai bahan aku panel, terutama jerami padi berjenis IR. Selanjutnya panel jerami ini perlu mendapatkan perlakukan uji desak dan lentur untuk memastikan kemampuannya menahan berat sendiri dan kekuatannya saat proses penggunaan, sebelum akhirnya mengalami pengujian berkaitan dengan kualitas akustik. Kekuatan desak dan lentur panel dimaksud, tersaji dalam tulisan ini. Kata kunci: panel jerami, uji desak, uji lentur.

Report of Industry Panel Group

Science.gov (United States)

Gallimore, Simon; Gier, Jochen; Heitland, Greg; Povinelli, Louis; Sharma, Om; VandeWall, Allen

2006-01-01

A final report is presented from the industry panel group. The contents include: 1) General comments; 2) Positive progress since Minnowbrook IV; 3) Industry panel outcome; 4) Prioritized turbine projects; 5) Prioritized compressor projects; and 6) Miscellaneous.

KUALITAS AKUSTIK PANEL DINDING BERBAHAN BAKU JERAMI

Directory of Open Access Journals (Sweden)

Christina E. Mediastika

2008-01-01

Full Text Available A series of study to explore possibility in using paddy-straw as main material to construct cheap and high quality panels has been developed. Prior to this study, laboratory research to examine strength of compression and tensile of the panels have been conducted, which is showed a significant value for a non-structural panel. The compression is 15 N/mm2 and tensile averaged at 0,5 N/mm2 . In this study, acoustic properties of the panels is to be examined, i.e.: transmission loss (TL, absorption coefficient (, and reverberation time (RT60. The test showed TL of 10 dB and 16 dB,  of 0,4 and 0,8 and improve RT60 from 0,88 sec to 0,35 sec and 0,16 sec (500 Hz is used for reference. Abstract in Bahasa Indonesia: Ketersediaan panel pelapis dinding yang bersifat akustik dengan harga yang lebih terjangkau seperti yang terbuat dari bahan limbah sangatlah penting. Pada penelitian awal telah diselidiki penggunaan jerami sebagai bahan baku pembuatan panel akustik, sekaligus telah dilakukan pengujian terhadap kareakteristik struktural (uji desak dan lentur dari panel tersebut. Dari uji kekuatan struktural, panel memiliki kekuatan desak mencapai 15 N/mm2 dan kuat lentur reta-rata 0,5 N/mm2. Kekuatan ini dianggap mencukupi bagi panel non-struktural yang hanya bertugas untuk memikul beban sendiri. Oleh karena tujuan awal pembuatan panel adalah untuk kepentingan akustik, maka pada penelitian lanjutan, dilakukan uji laboratorium dan lapangan untuk melihat karakterisktik akustiknya. Adapun pengujian meliputi: redaman/insulasi (TL, koefisien serap ( dan waktu dengung (RT60. Dari hasil pengujian, panel mempunyai TL 10 dB dan 16 dB,  0,4 dan 0,8, serta mampu memperbaiki RT60 ruangan dari 0,88 detik menjadi 0,35 detik dan 0,16 detik. Kesemua pengujian menggunakan band frekuensi 500 Hz sebagai acuan. Kata kunci: panel jerami, insulasi, koefisien serap, waktu dengung.

Genomic characterization of recurrent high-grade astroblastoma.

Science.gov (United States)

Bale, Tejus A; Abedalthagafi, Malak; Bi, Wenya Linda; Kang, Yun Jee; Merrill, Parker; Dunn, Ian F; Dubuc, Adrian; Charbonneau, Sarah K; Brown, Loreal; Ligon, Azra H; Ramkissoon, Shakti H; Ligon, Keith L

2016-01-01

Astroblastomas are rare primary brain tumors, diagnosed based on histologic features. Not currently assigned a WHO grade, they typically display indolent behavior, with occasional variants taking a more aggressive course. We characterized the immunohistochemical characteristics, copy number (high-resolution array comparative genomic hybridization, OncoCopy) and mutational profile (targeted next-generation exome sequencing, OncoPanel) of a cohort of seven biopsies from four patients to identify recurrent genomic events that may help distinguish astroblastomas from other more common high-grade gliomas. We found that tumor histology was variable across patients and between primary and recurrent tumor samples. No common molecular features were identified among the four tumors. Mutations commonly observed in astrocytic tumors (IDH1/2, TP53, ATRX, and PTEN) or ependymoma were not identified. However one case with rapid clinical progression displayed mutations more commonly associated with GBM (NF1(N1054H/K63)*, PIK3CA(R38H) and ERG(A403T)). Conversely, another case, originally classified as glioblastoma with nine-year survival before recurrence, lacked a GBM mutational profile. Other mutations frequently seen in lower grade gliomas (BCOR, BCORL1, ERBB3, MYB, ATM) were also present in several tumors. Copy number changes were variable across tumors. Our findings indicate that astroblastomas have variable growth patterns and morphologic features, posing significant challenges to accurate classification in the absence of diagnostically specific copy number alterations and molecular features. Their histopathologic overlap with glioblastoma will likely confound the observation of long-term GBM "survivors". Further genomic profiling is needed to determine whether these tumors represent a distinct entity and to guide management strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

Vibration of functionally graded plate resting on viscoelastic elastic foundation subjected to moving loads

Science.gov (United States)

Duy Hien, Ta; Lam, Nguyen Ngoc

2018-04-01

The dynamics of plates subjected to a moving load must be considered by engineering mechanics and design structures. This paper deals with the dynamic responses of functionally graded (FG) rectangular plates resting on a viscoelastic foundation under moving loads. It is assumed that material properties of the plate vary continuously in the thickness direction according to the power-law. The governing equations are derived by using Hamilton’s principle, which considers the effect of the higher-order shear deformation in the plate. Transient responses of simply supported FG rectangular plates are employed by using state-space methods. Several examples are given for displacement and stresses in the plates with various structural parameters, and the effects of these parameters are discussed.

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

Science.gov (United States)

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

2013-03-01

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

Panel Smooth Transition Regression Models

DEFF Research Database (Denmark)

González, Andrés; Terasvirta, Timo; Dijk, Dick van

We introduce the panel smooth transition regression model. This new model is intended for characterizing heterogeneous panels, allowing the regression coefficients to vary both across individuals and over time. Specifically, heterogeneity is allowed for by assuming that these coefficients are bou...

Acute effects of PM2.5 on lung function parameters in schoolchildren in Nanjing, China: a panel study.

Science.gov (United States)

Xu, Dandan; Zhang, Yi; Zhou, Lian; Li, Tiantian

2018-03-17

The association between exposure to ambient particulate matter (PM) and reduced lung function parameters has been reported in many works. However, few studies have been conducted in developing countries with high levels of air pollution like China, and little attention has been paid to the acute effects of short-term exposure to air pollution on lung function. The study design consisted of a panel comprising 86 children from the same school in Nanjing, China. Four measurements of lung function were performed. A mixed-effects regression model with study participant as a random effect was used to investigate the relationship between PM 2.5 and lung function. An increase in the current day, 1-day and 2-day moving average PM 2.5 concentration was associated with decreases in lung function indicators. The greatest effect of PM 2.5 on lung function was detected at 1-day moving average PM 2.5 exposure. An increase of 10 μg/m 3 in the 1-day moving average PM 2.5 concentration was associated with a 23.22 mL decrease (95% CI: 13.19, 33.25) in Forced Vital Capacity (FVC), a 18.93 mL decrease (95% CI: 9.34, 28.52) in 1-s Forced Expiratory Volume (FEV 1 ), a 29.38 mL/s decrease (95% CI: -0.40, 59.15) in Peak Expiratory Flow (PEF), and a 27.21 mL/s decrease (95% CI: 8.38, 46.04) in forced expiratory flow 25-75% (FEF 25-75% ). The effects of PM 2.5 on lung function had significant lag effects. After an air pollution event, the health effects last for several days and we still need to pay attention to health protection.

Hexagon solar power panel

Science.gov (United States)

Rubin, I. (Inventor)

1978-01-01

A solar energy panel support is described upon which silicon cells are arrayed. The cells are wafer thin and of two geometrical types, both of the same area and electrical rating, namely hexagon cells and hourglass cells. The hourglass cells are composites of half hexagons. A near perfect nesting relationship of the cells achieves a high density packing whereby optimum energy production per panel area is achieved.

Control panel for CMC 8080 crate controller

International Nuclear Information System (INIS)

Masayuki Inokuchi

1978-01-01

The main features of Control Panel for CAMAC Crate Controller CMC 8080 are described. The control panel can be directly connected with CRATE CONTROLLER's front panel connector with a 50 lines cable without any changes in CMC 8080 system circuits. (author)

Computer Aided Analysis of TM-Multimode Planar Graded-index Optical Waveguides

International Nuclear Information System (INIS)

Ashry, M.; Nasr, A.S.; Abou El-Fadl, A.A.

2000-01-01

An algorithm is developed for analysis TM-Multimode Planar graded-index optical waveguides. A Modified Impedance Boundary Method of Moments (MIBMOM) for the analysis of planar graded-index optical waveguide structures is presented. The algorithm is used to calculate the dispersion characteristics and the field distribution of TM-multimode planar graded-index optical waveguides. The technique is based on Galerkin s procedure and the exact boundary condition at the interfaces between the graded index region and the step index cladding. Legendre polynomials are used as basis functions. The efficiency of this algorithm is examined with waveguides having various index profiles such as exponential, Gaussian and complementary error functions. The advantage of the MIBMOM is the complete solution of TM-multimode as presented which is very difficult by the other methods. With this algorithm a minimum number of basis functions to give accurate results is used. The obtained results show good agreement with the experimental results

Light redirecting system using sine-wave based panels for dense urban areas

Science.gov (United States)

Mohamed, Mohamed W. N.; Mashaly, Islam A.; Mohamed, Osama N.; El-Henawy, Sally I.; Galal, Ola; Taha, Iman; Nassar, Khaled; Safwat, Amr M. E.

2014-09-01

Cities and towns around the world are becoming more condensed due to the shrinking amount of buildable areas, which significantly reduces the amount of light that occupants have access to. This lack of natural lighting results in health, safety and quality of life degradation. This paper presents a new technique of transmitting sunlight downward into narrow alleys and streets, by using a daylighting guiding acrylic panel that is capable of changing the direction and distribution of the incident light. The core of the proposed daylight guidance system is made up of light transmission panels with high quality. The corrugations have sine wave shaped cross-section so that the panel functions as an optical diffuser perpendicular to the direction of sunlight propagation. The day lighting system consists of the corrugated panels and a lattice frame, which supports the panel. The proposed system is to be mounted on the building roof facing the sun so as to redirect the incident sunlight downward into the narrow alleys or streets. Since building sizes and orientations are different the frame is arranged such that substantially deep light penetration and high luminance level can be achieved. Simulation results show that the proposed panel improves the illuminance values by more than 200% and 400% in autumn and winter, respectively, provides fan-out angle that exceeds 80° for certain solar altitudes and the transmitted power percentage varies from 40% to 90% as the solar altitude varies from 10° to 80°. Experimental results are in a good agreement with the simulations.

PV panel model based on datasheet values

DEFF Research Database (Denmark)

Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

2007-01-01

This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell....... Based on these equations, a PV panel model, which is able to predict the panel behavior in different temperature and irradiance conditions, is built and tested....

Consumer and trained panel evaluation of beef strip steaks of varying marbling and enhancement levels cooked to three degrees of doneness.

Science.gov (United States)

Lucherk, L W; O'Quinn, T G; Legako, J F; Rathmann, R J; Brooks, J C; Miller, M F

2016-12-01

The palatability of USDA graded beef strip loins of seven treatments [High Enhanced (HE: 112% of raw weight) Select, Low Enhanced (LE: 107% of raw weight) Select, Prime, upper 2/3 Choice (Top Choice), lower 1/3 Choice (Low Choice), Select, and Standard] cooked to three degrees of doneness [DOD; rare (60°C), medium (71°C), or well-done (77°C)] was evaluated by consumer and trained sensory panelists. For consumers, Select HE steaks rated higher (P0.05) were observed between Select LE and Prime samples for most traits evaluated. The effect of USDA grade and enhancement on trained panel palatability scores was independent of DOD for all traits other than juiciness, with the role of marbling in juiciness increasing as DOD increased from rare to well-done. These results indicate enhancement as an effective method to improve the palatability of lower grading beef. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thin film photovoltaic panel and method

Science.gov (United States)

Ackerman, Bruce; Albright, Scot P.; Jordan, John F.

1991-06-11

A thin film photovoltaic panel includes a backcap for protecting the active components of the photovoltaic cells from adverse environmental elements. A spacing between the backcap and a top electrode layer is preferably filled with a desiccant to further reduce water vapor contamination of the environment surrounding the photovoltaic cells. The contamination of the spacing between the backcap and the cells may be further reduced by passing a selected gas through the spacing subsequent to sealing the backcap to the base of the photovoltaic panels, and once purged this spacing may be filled with an inert gas. The techniques of the present invention are preferably applied to thin film photovoltaic panels each formed from a plurality of photovoltaic cells arranged on a vitreous substrate. The stability of photovoltaic conversion efficiency remains relatively high during the life of the photovoltaic panel, and the cost of manufacturing highly efficient panels with such improved stability is significantly reduced.

A highly diverse, desert-like microbial biocenosis on solar panels in a Mediterranean city.

Science.gov (United States)

Dorado-Morales, Pedro; Vilanova, Cristina; Peretó, Juli; Codoñer, Francisco M; Ramón, Daniel; Porcar, Manuel

2016-07-05

Microorganisms colonize a wide range of natural and artificial environments although there are hardly any data on the microbial ecology of one the most widespread man-made extreme structures: solar panels. Here we show that solar panels in a Mediterranean city (Valencia, Spain) harbor a highly diverse microbial community with more than 500 different species per panel, most of which belong to drought-, heat- and radiation-adapted bacterial genera, and sun-irradiation adapted epiphytic fungi. The taxonomic and functional profiles of this microbial community and the characterization of selected culturable bacteria reveal the existence of a diverse mesophilic microbial community on the panels' surface. This biocenosis proved to be more similar to the ones inhabiting deserts than to any human or urban microbial ecosystem. This unique microbial community shows different day/night proteomic profiles; it is dominated by reddish pigment- and sphingolipid-producers, and is adapted to withstand circadian cycles of high temperatures, desiccation and solar radiation.

Wsbnd Cu functionally graded material: Low temperature fabrication and mechanical characterization

Science.gov (United States)

Yusefi, Ali; Parvin, Nader; Mohammadi, Hossein

2018-04-01

In this study, we fabricated and characterized a Wsbnd Cu functionally graded material (FGM) with 11 layers, including a pure copper layer. Samples were prepared by mixing a mechanically alloyed Nisbnd Mnsbnd Cu powder with W and Cu powders, stacking the powders, pressing the stacked layers, and finally sintering at 1000 °C. The utilization of a Nisbnd Mnsbnd Cu system may reduce the cost but without losing the good sintering behavior and physical and mechanical properties. The composition of the material was analyzed based on scanning electron microscopy images and by energy dispersive X-ray spectroscopy mapping, which indicated that in the presence of Ni and Mn, the Cu atoms could diffuse into the W particles. All of the layers had a very high relative density, thereby indicating their densification and excellent sintering behavior. We also found that the porosity values in the Cu phase remained unchanged at approximately 2.39% across the FGM. Mechanical measurements showed that the hardness (72%), modulus of elasticity (61%), and ultimate tensile strength (58%) increased with the W content across the Wsbnd Cu FGM, whereas the fracture toughness (KIC) varied in the opposite manner (minimum of 4.52 MPa/m0.5).

Aerosol Deposition and Solar Panel Performance

Science.gov (United States)

Arnott, W. P.; Rollings, A.; Taylor, S. J.; Parks, J.; Barnard, J.; Holmes, H.

2015-12-01

Passive and active solar collector farms are often located in relatively dry desert regions where cloudiness impacts are minimized. These farms may be susceptible to reduced performance due to routine or episodic aerosol deposition on collector surfaces. Intense episodes of wind blown dust deposition may negatively impact farm performance, and trigger need to clean collector surfaces. Aerosol deposition rate depends on size, morphology, and local meteorological conditions. We have developed a system for solar panel performance testing under real world conditions. Two identical 0.74 square meter solar panels are deployed, with one kept clean while the other receives various doses of aerosol deposition or other treatments. A variable load is used with automation to record solar panel maximum output power every 10 minutes. A collocated sonic anemometer measures wind at 10 Hz, allowing for both steady and turbulent characterization to establish a link between wind patterns and particle distribution on the cells. Multispectral photoacoustic instruments measure aerosol light scattering and absorption. An MFRSR quantifies incoming solar radiation. Solar panel albedo is measured along with the transmission spectra of particles collected on the panel surface. Key questions are: At what concentration does aerosol deposition become a problem for solar panel performance? What are the meteorological conditions that most strongly favor aerosol deposition, and are these predictable from current models? Is it feasible to use the outflow from an unmanned aerial vehicle hovering over solar panels to adequately clean their surface? Does aerosol deposition from episodes of nearby forest fires impact performance? The outlook of this research is to build a model that describes environmental effects on solar panel performance. Measurements from summer and fall 2015 will be presented along with insights gleaned from them.

Optimal Fuzzy and Dynamics Design of Ecological Sandwich Panel Vessel Roofs

Directory of Open Access Journals (Sweden)

Heikki Martikka

2011-01-01

Full Text Available In this study the basic engineering principles, goals, and constraints are all combined with fuzzy methodology and applied to optimally design sandwich panel circular plate roofs for large vessels loaded statically and dynamically. These panels are made up of two stiff, strong veneer skins separated by vertical and peripheral stiffener plates. Advantages are high strength, lightweight, and sustainability. In the present approach, first the goals and constraints of the end user are identified and expressed as decision variables which are formulated using the engineering variables for materials, geometry, and function. Then same consistent fuzzy satisfaction functions are formed over the desired ranges to suit the customer's desires. The risk of extreme dynamic loadings exciting resonance is studied by natural frequency and mode analysis by FEM and analytical models. The results show the most critical locations and give guidelines for innovative remedies of the concept before detailed FEM analyses to finalize the design.

Numerical simulation of wind loads on solar panels

Science.gov (United States)

Su, Kao-Chun; Chung, Kung-Ming; Hsu, Shu-Tsung

2018-05-01

Solar panels mounted on the roof of a building or ground are often vulnerable to strong wind loads. This study aims to investigate wind loads on solar panels using computational fluid dynamic (CFD). The results show good agreement with wind tunnel data, e.g. the streamwise distribution of mean surface pressure coefficient of a solar panel. Wind uplift for solar panels with four aspect ratios is evaluated. The effect of inclined angle and clearance (or height) of a solar panel is addressed. It is found that wind uplift of a solar panel increases when there is an increase in inclined angle and the clearance above ground shows an opposite effect.

7 CFR 810.2204 - Grades and grade requirements for wheat.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Grades and grade requirements for wheat. 810.2204... OFFICIAL UNITED STATES STANDARDS FOR GRAIN United States Standards for Wheat Principles Governing the Application of Standards § 810.2204 Grades and grade requirements for wheat. (a) Grades and grade requirements...

Integrally rigidized acoustic interior spacecraft panel

Science.gov (United States)

1976-01-01

A sandwich panel concept is described which utilizes a monolithic I-beam design as the core. The core and skins are integrally bonded with thermosetting resin into a homogeneous structure. In addition to possessing a high strength to weight ratio, the panel resists combustion, delamination, aging due to fatigue, localized stresses, and exhibits good acoustic properties. Since the panel concept has definite potential as a high flame retardant and low smoke emission panel with excellent structural integrity, aerospace materials were used to optimize the construction for highly demanding space shuttle applications. The specific materials of construction were chosen for low flammability and off-gassing properties as well as for strength, light weight, and sound dampening.

Effects of decompressive craniectomy on functional outcomes and death in poor-grade aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

Science.gov (United States)

Alotaibi, Naif M; Elkarim, Ghassan Awad; Samuel, Nardin; Ayling, Oliver G S; Guha, Daipayan; Fallah, Aria; Aldakkan, Abdulrahman; Jaja, Blessing N R; de Oliveira Manoel, Airton Leonardo; Ibrahim, George M; Macdonald, R Loch

2017-12-01

OBJECTIVE Patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) (World Federation of Neurosurgical Societies Grade IV or V) are often considered for decompressive craniectomy (DC) as a rescue therapy for refractory intracranial hypertension. The authors performed a systematic review and meta-analysis to assess the impact of DC on functional outcome and death in patients after poor-grade aSAH. METHODS A systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles were identified through the Ovid Medline, Embase, Web of Science, and Cochrane Library databases from inception to October 2015. Only studies dedicated to patients with poor-grade aSAH were included. Primary outcomes were death and functional outcome assessed at any time period. Patients were grouped as having a favorable outcome (modified Rankin Scale [mRS] Scores 1-3, Glasgow Outcome Scale [GOS] Scores 4 and 5, extended Glasgow Outcome Scale [GOSE] Scores 5-8) or unfavorable outcome (mRS Scores 4-6, GOS Scores 1-3, GOSE Scores 1-4). Pooled estimates of event rates and odds ratios with 95% confidence intervals were calculated using the random-effects model. RESULTS Fifteen studies encompassing 407 patients were included in the meta-analysis (all observational cohorts). The pooled event rate for poor outcome across all studies was 61.2% (95% CI 52%-69%) and for death was 27.8% (95% CI 21%-35%) at a median of 12 months after aSAH. Primary (or early) DC resulted in a lower overall event rate for unfavorable outcome than secondary (or delayed) DC (47.5% [95% CI 31%-64%] vs 74.4% [95% CI 43%-91%], respectively). Among studies with comparison groups, there was a trend toward a reduced mortality rate 1-3 months after discharge among patients who did not undergo DC (OR 0.58 [95% CI 0.27-1.25]; p = 0.168). However, this trend was not sustained at the 1-year follow-up (OR 1.09 [95% CI 0

A panel study of migration, self-selection and household real income.

Science.gov (United States)

Axelsson, R; Westerlund, O

1998-02-01

"The impact of migration on income for Swedish multi-adult households is examined using panel data pertaining to a sample of stable household constellations during the period 1980-1990. In contrast to previous studies, data on household disposable income is employed in estimating the income function. The empirical results indicate no significant effect on real disposable income from migration. In addition, the hypothesis of no self-selection, or zero correlation between the errors in the decision function and the income function, cannot be rejected." excerpt

Matlab Software for Spatial Panels

NARCIS (Netherlands)

Elhorst, J.Paul

2014-01-01

Elhorst provides Matlab routines to estimate spatial panel data models at his website. This article extends these routines to include the bias correction procedure proposed by Lee and Yu if the spatial panel data model contains spatial and/or time-period fixed effects, the direct and indirect

Panel 3 - characterization

Energy Technology Data Exchange (ETDEWEB)

Erck, R.A.; Erdemir, A.; Janghsing Hsieh; Lee, R.H.; Xian Zheng Pan; Deming Shu [Argonne National Lab., IL (United States); Feldman, A. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Glass, J.T. [North Carolina State Univ., Raleigh (United States); Kleimer, R. [Coors Ceramics Co., Golden, CO (United States); Lawton, E.A. [JPL/Caltech, Pasadena, CA (United States); McHargue, C.J. [Univ. of Tennessee, Knoxville (United States)

1993-01-01

The task of this panel was to identify and prioritize needs in the area of characterization of diamond and diamond-like-carbon (DLC) films for use in the transportation industry. Until recent advances in production of inexpensive films of diamonds and DLC, it was not feasible that these materials could be mass produced. The Characterization Panel is restricting itself to identifying needs in areas that would be most useful to manufacturers and users in producing and utilizing diamond and DLC coatings in industry. These characterization needs include in-situ monitoring during growth, relation of structure to performance, and standards and definitions.

Development of panel loudspeaker system: design, evaluation and enhancement.

Science.gov (United States)

Bai, M R; Huang, T

2001-06-01

Panel speakers are investigated in terms of structural vibration and acoustic radiation. A panel speaker primarily consists of a panel and an inertia exciter. Contrary to conventional speakers, flexural resonance is encouraged such that the panel vibrates as randomly as possible. Simulation tools are developed to facilitate system integration of panel speakers. In particular, electro-mechanical analogy, finite element analysis, and fast Fourier transform are employed to predict panel vibration and the acoustic radiation. Design procedures are also summarized. In order to compare the panel speakers with the conventional speakers, experimental investigations were undertaken to evaluate frequency response, directional response, sensitivity, efficiency, and harmonic distortion of both speakers. The results revealed that the panel speakers suffered from a problem of sensitivity and efficiency. To alleviate the problem, a woofer using electronic compensation based on H2 model matching principle is utilized to supplement the bass response. As indicated in the result, significant improvement over the panel speaker alone was achieved by using the combined panel-woofer system.

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

CERN Document Server

Dantz, D; Reimers, W

1999-01-01

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

Solar Panel Installations on Existing Structures

OpenAIRE

Tim D. Sass; Pe; Leed

2013-01-01

The rising price of fossil fuels, government incentives and growing public aware-ness for the need to implement sustainable energy supplies has resulted in a large in-crease in solar panel installations across the country. For many sites the most eco-nomical solar panel installation uses existing, southerly facing rooftops. Adding solar panels to an existing roof typically means increased loads that must be borne by the building-s structural elements. The structural desig...

Deposition and characterization of plasma sprayed Ni-5A1/ magnesia stabilized zirconia based functionally graded thermal barrier coating

International Nuclear Information System (INIS)

Baig, M N; Khalid, F A

2014-01-01

Thermal barrier coatings (TBCs) are employed to protect hot section components in industrial and aerospace gas turbine engines. Conventional TBCs frequently fail due to high residual stresses and difference between coefficient of thermal expansion (CTE) of the substrate and coatings. Functionally graded thermal barrier coatings (FG-TBCs) with gradual variation in composition have been proposed to minimize the problem. In this work, a five layered functionally graded thermal barrier coating system was deposited by atmospheric plasma spray (APS) technique on Nimonic 90 substrates using Ni-5Al as bond coat (BC) and magnesia stabilized zirconia as top coat (TC). The coatings were characterized by SEM, EDS, XRD and optical profilometer. Microhardness and coefficient of thermal expansion of the five layers deposited as individual coatings were also measured. The deposited coating system was oxidized at 800°C. SEM analysis showed that five layers were successfully deposited by APS to produce a FG-TBC. The results also showed that roughness (Ra) of the individual layers decreased with an increase in TC content in the coatings. It was found that microhardness and CTE values gradually changed from bond coat to cermet layers to top coat. The oxidized coated sample revealed parabolic behavior and changes in the surface morphology and composition of coating

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

Science.gov (United States)

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

1995-01-01

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

78 FR 63501 - Meetings of Humanities Panel

Science.gov (United States)

2013-10-24

... NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES Meetings of Humanities Panel AGENCY: National Endowment for the Humanities. ACTION: Notice of meetings. SUMMARY: Pursuant to section 10(a)(2) of the... Humanities Panel will be held during November, 2013 as follows. The purpose of the meetings is for panel...

Delayed Presentation of Ureteropelvic Junction Obstruction and Loss of Renal Function After Initially Mild (SFU Grade 1-2) Hydronephrosis.

Science.gov (United States)

Bowen, Diana K; Yerkes, Elizabeth B; Lindgren, Bruce W; Gong, Edward M; Faasse, Mark A

2015-07-01

We report 4 pediatric cases of ureteropelvic junction obstruction involving delayed progression of initially mild postnatal hydronephrosis. All 4 children became symptomatic; however, 3 already had a substantial decrement of ipsilateral kidney function by the time of diagnosis. Two of these 3 patients had previous renal scintigraphy demonstrating normal differential function. We caution that counseling regarding hydronephrosis should emphasize the importance of prompt re-evaluation for any symptoms potentially referable to delayed presentation of ureteropelvic junction obstruction, irrespective of initial hydronephrosis grade. Future studies are needed to determine the optimal follow-up regimen for conservative management of hydronephrosis. Copyright © 2015 Elsevier Inc. All rights reserved.

Uncertainties in predicting solar panel power output

Science.gov (United States)

Anspaugh, B.

1974-01-01

The problem of calculating solar panel power output at launch and during a space mission is considered. The major sources of uncertainty and error in predicting the post launch electrical performance of the panel are considered. A general discussion of error analysis is given. Examples of uncertainty calculations are included. A general method of calculating the effect on the panel of various degrading environments is presented, with references supplied for specific methods. A technique for sizing a solar panel for a required mission power profile is developed.

Report of the Federal Internetworking Requirements Panel

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-05-31

The Federal Internetworking Requirements Panel (FIRP) was established by the National Institute of Standards and Technology (NIST) to reassess Federal requirements for open systems networks and to recommend policy on the Government`s use of networking standards. The Panel was chartered to recommend actions which the Federal Government can take to address the short and long-term issues of interworking and convergence of networking protocols--particularly the Internet Protocol Suite (IPS) and Open Systems Interconnection (OSI) protocol suite and, when appropriate, proprietary protocols. The Panel was created at the request of the Office of Management and Budget in collaboration with the Federal Networking Council and the Federal Information Resources Management Policy Council. The Panel`s membership and charter are contained in an appendix to this report.

Thermal Analysis of Solar Panels

Science.gov (United States)

Barth, Nicolas; de Correia, João Pedro Magalhães; Ahzi, Saïd; Khaleel, Mohammad Ahmed

In this work, we propose to analyze the thermal behavior of PV panels using finite element simulations (FEM). We applied this analysis to compute the temperature distribution in a PV panel BP 350 subjected to different atmospheric conditions. This analysis takes into account existing formulations in the literature and, based on NOCT conditions, meteorological data was used to validate our approach for different wind speed and solar irradiance. The electrical performance of the PV panel was also studied. The proposed 2D FEM analysis is applied to different region's climates and was also used to consider the role of thermal inertia on the optimization of the PV device efficiency.

Optimized functionally graded La2Zr2O7/8YSZ thermal barrier coatings fabricated by suspension plasma spraying

International Nuclear Information System (INIS)

Wang, Chaohui; Wang, You; Fan, Shan; You, Yuan; Wang, Liang; Yang, Changlong; Sun, Xiaoguang; Li, Xuewei

2015-01-01

In this paper, an optimized functionally graded coating (OFGC) was successfully fabricated by suspension plasma spraying (SPS) with feedstocks of the suspension of nanoparticles. La 2 Zr 2 O 7 /8YSZ OFGC with gradual compositional variation along the through-thickness direction is proposed to mitigate spallation and crack formation owing to the high residual stresses caused by frequent thermal cycling for TBCs. The single ceramic layer coatings (SCLC) of LZ and double ceramic layer coatings (DCLC) of LZ/8YSZ were fabricated by SPS as comparison. The phase composition and microstructure of the SCLC, OFGC and DCLC were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS). Moreover, the thermal cycling tests were carried out to evaluate their thermal shock behavior. Changes in weight and morphology of specimens were analyzed during thermal cycling tests. The results showed that OFGC has extended lifetime compared with SCLC and DCLC. The failure of DCLC with clear interface between different ceramic layers occurred via delamination mode, as a result of crack initiation and propagation generated by thermal mismatch between LZ and 8YSZ. While the failure of OFGC occurred in thermally grown oxide (TGO) layers, indicating that the gradual compositional variation avoided thermal stress concentration in the top ceramic layers. - Highlights: • Optimized functionally graded coatings and double ceramic layer coatings were deposited by suspension plasma spray. • The graded area of OFGC is continuously changed from inner 8YSZ to outer La 2 Zr 2 O 7 (LZ). • The OFGC shows a more extended thermal cycling life than the LZ SCLC and LZ/8YSZ DCLC. • Various failure mechanisms were proposed to explain thermal cycling behavior

78 FR 74175 - Meetings of Humanities Panel

Science.gov (United States)

2013-12-10

... NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES Meetings of Humanities Panel AGENCY: National Endowment for the Humanities. ACTION: Notice of meetings. SUMMARY: Pursuant to section 10(a)(2) of the... Humanities Panel will be held during January 2014 as follows. The purpose of the meetings is for panel review...

32 CFR 724.104 - NDRB Traveling Panel.

Science.gov (United States)

2010-07-01

... 32 National Defense 5 2010-07-01 2010-07-01 false NDRB Traveling Panel. 724.104 Section 724.104 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY PERSONNEL NAVAL DISCHARGE REVIEW BOARD Definitions § 724.104 NDRB Traveling Panel. An NDRB Panel that travels for the purpose of...

Precast concrete sandwich panels subjected to impact loading

Science.gov (United States)

Runge, Matthew W.

Precast concrete sandwich panels are a relatively new product in the construction industry. The design of these panels incorporates properties that allow for great resilience against temperature fluctuation as well as the very rapid and precise construction of facilities. The concrete sandwich panels investigated in this study represent the second generation of an ongoing research and development project. This second generation of panels have been engineered to construct midsized commercial buildings up to three stories in height as well as residential dwellings. The panels consist of a double-tee structural wythe, a foam core and a fascia wythe, joined by shear connectors. Structures constructed from these panels may be subjected to extreme loading including the effects of seismic and blast loading in addition to wind. The aim of this work was to investigate the behaviour of this particular sandwich panel when subjected to structural impact events. The experimental program consisted of fourteen concrete sandwich panels, five of which were considered full-sized specimens (2700 mm X 1200mm X 270 mm) and nine half-sized specimens (2700mm X 600mm X 270 mm) The panels were subjected to impact loads from a pendulum impact hammer where the total energy applied to the panels was varied by changing the mass of the hammer. The applied loads, displacements, accelerations, and strains at the mid-span of the panel as well as the reaction point forces were monitored during the impact. The behaviour of the panels was determined primarily from the experimental results. The applied loads at low energy levels that caused little to no residual deflection as well as the applied loads at high energy levels that represent catastrophic events and thus caused immediate failure were determined from an impact on the structural and the fascia wythes. Applied loads at intermediate energy levels representing extreme events were also used to determine whether or not the panels could withstand

Case Study - Monitoring the Photovoltaic Panels

OpenAIRE

PACURAR Ana Talida; TOADER Dumitru; PACURAR Cristian

2014-01-01

The photovoltaic cell represents one of the most dynamic and attractive way to converts renewable energy sources in electricity production. That means to convert solar energy into electricity. In this paper is presented a analogy between two types of photovoltaic panels installed, with educational role for students. Also the objective of this paper is to estimate the performance of photovoltaic panels and to provide the best solution for industry. These two types of photovoltaic panels wer...

El Salvador - Rural Electrification - Solar Panels

Data.gov (United States)

Millennium Challenge Corporation — This is a summative qualitative performance evaluation (PE) of the solar panel component of the solar panel component of the RE Sub-Activity. The final report will...

Nanoindentation of Functionally Graded Polymer Nanocomposites: Assessment of the Strengthening Parameters through Experiments and Modeling

Directory of Open Access Journals (Sweden)

Tommaso eNardi

2015-08-01

Full Text Available NNanoindentation tests were carried out on the surface of polymer nanocomposites exhibiting either graded or homogeneous distributions of Fe3O4@silica core-shell nanoparticles in a photocurable polymeric matrix. The results reveal a complex interplay between graded morphology, indentation depth and calculated modulus and hardness values, which was elucidated through numerical simulations. First, it was experimentally shown how for small (1 µm indentations, large increases in modulus (up to +40% and hardness (up to +93% were obtained for graded composites with respect to their homogeneous counterparts, whereas at a larger indentation depth (20 µm the modulus and hardness of the graded and homogeneous composites did not substantially differ from each other and from those of the pure polymer. Then, through a Material Point Method approach, experimental nanoindentation tests were successfully simulated, confirming the importance of the indentation depth and of the associated plastic zone as key factors for a more accurate design of graded polymer nanocomposites whose mechanical properties are able to fulfill the requirements encountered during operational life.

Spinodal Decomposition in Functionally Graded Super Duplex Stainless Steel and Weld Metal

Science.gov (United States)

Hosseini, Vahid A.; Thuvander, Mattias; Wessman, Sten; Karlsson, Leif

2018-04-01

Low-temperature phase separations (T duplex stainless steel (SDSS) base and weld metals were investigated for short heat treatment times (0.5 to 600 minutes). A novel heat treatment technique, where a stationary arc produces a steady state temperature gradient for selected times, was employed to fabricate functionally graded materials. Three different initial material conditions including 2507 SDSS, remelted 2507 SDSS, and 2509 SDSS weld metal were investigated. Selective etching of ferrite significantly decreased in regions heat treated at 435 °C to 480 °C already after 3 minutes due to rapid phase separations. Atom probe tomography results revealed spinodal decomposition of ferrite and precipitation of Cu particles. Microhardness mapping showed that as-welded microstructure and/or higher Ni content accelerated decomposition. The arc heat treatment technique combined with microhardness mapping and electrolytical etching was found to be a successful approach to evaluate kinetics of low-temperature phase separations in SDSS, particularly at its earlier stages. A time-temperature transformation diagram was proposed showing the kinetics of 475 °C-embrittlement in 2507 SDSS.

Daytime space cooling with phase change material ceiling panels discharged using rooftop photovoltaic/thermal panels and night-time ventilation

DEFF Research Database (Denmark)

Bourdakis, Eleftherios; Pean, Thibault Quentin; Gennari, Luca

2016-01-01

The possibility of using photovoltaic/thermal panels for producing cold water through the process of night-time radiative cooling was experimentally examined. The cold water was used to discharge phase change material in ceiling panels in a climatic chamber. Both night-time radiative cooling...... the photovoltaic/thermal varied from 56% to 122%. The phase change material ceiling panels were thus, capable of providing an acceptable thermal environment and the photovoltaic/thermal panels were able to provide most of the required electricity and cold water needed for cooling....

7 CFR 205.509 - Peer review panel.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Peer review panel. 205.509 Section 205.509 Agriculture... PROVISIONS NATIONAL ORGANIC PROGRAM Accreditation of Certifying Agents § 205.509 Peer review panel. The Administrator shall establish a peer review panel pursuant to the Federal Advisory Committee Act (FACA) (5 U.S.C...

Piezoelectricity above the Curie temperature? Combining flexoelectricity and functional grading to enable high-temperature electromechanical coupling

Energy Technology Data Exchange (ETDEWEB)

Mbarki, R. [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204 (United States); Baccam, N. [Department of Mathematics, Southwestern University, Georgetown, Texas 78626 (United States); Dayal, Kaushik [Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Sharma, P. [Department of Mechanical Engineering and Department of Physics, University of Houston, Houston, Texas 77204 (United States)

2014-03-24

Most technologically relevant ferroelectrics typically lose piezoelectricity above the Curie temperature. This limits their use to relatively low temperatures. In this Letter, exploiting a combination of flexoelectricity and simple functional grading, we propose a strategy for high-temperature electromechanical coupling in a standard thin film configuration. We use continuum modeling to quantitatively demonstrate the possibility of achieving apparent piezoelectric materials with large and temperature-stable electromechanical coupling across a wide temperature range that extends significantly above the Curie temperature. With Barium and Strontium Titanate, as example materials, a significant electromechanical coupling that is potentially temperature-stable up to 900 °C is possible.

Performance analysis of PV panel under varying surface temperature

Directory of Open Access Journals (Sweden)

Kumar Tripathi Abhishek