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Sample records for waste elastic properties

  1. HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SENSITIVITY OF DOUBLE SHELL DYNAMIC RESPONSE TO THE WASTE ELASTIC PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    MACKEY TC; ABATT FG; JOHNSON KI

    2009-01-16

    The purpose of this study was to determine the sensitivity of the dynamic response of the Hanford double-shell tanks (DSTs) to the assumptions regarding the constitutive properties of the contained waste. In all cases, the waste was modeled as a uniform linearly elastic material. The focus of the study was on the changes in the modal response of the tank and waste system as the extensional modulus (elastic modulus in tension and compression) and shear modulus of the waste were varied through six orders of magnitude. Time-history analyses were also performed for selected cases and peak horizontal reaction forces and axial stresses at the bottom of the primary tank were evaluated. Because the analysis focused on the differences in the responses between solid-filled and liquid-filled tanks, it is a comparative analysis rather than an analysis of record for a specific tank or set of tanks. The shear modulus was varied between 4 x 10{sup 3} Pa and 4.135 x 10{sup 9} Pa. The lowest value of shear modulus was sufficient to simulate the modal response of a liquid-containing tank, while the higher values are several orders of magnitude greater than the upper limit of expected properties for tank contents. The range of elastic properties used was sufficient to show liquid-like response at the lower values, followed by a transition range of semi-solid-like response to a clearly identifiable solid-like response. It was assumed that the mechanical properties of the tank contents were spatially uniform. Because sludge-like materials are expected only to exist in the lower part of the tanks, this assumption leads to an exaggeration of the effects of sludge-like materials in the tanks. The results of the study show that up to a waste shear modulus of at least 40,000 Pa, the modal properties of the tank and waste system are very nearly the same as for the equivalent liquid-containing tank. This suggests that the differences in critical tank responses between liquid-containing tanks

  2. Elastic Properties of HMX

    Science.gov (United States)

    Sewell, Thomas D.; Bedrov, Dmitry; Menikoff, Ralph; Smith, Grant D.

    2002-07-01

    Atomistic molecular dynamics simulations have been used to calculate isothermal elastic properties for beta-, alpha-, and delta-HMX. The complete elastic tensor for each polymorph was determined at room temperature and pressure via analysis of microscopic strain fluctuations using formalism due to Rahman and Parrinello [J. Chem. Phys. 76, 2662 (1982)]. Additionally, the isothermal compression curve was computed for beta-HMX for 0 less-than-or-equal p less-than-or-equal 10.6 GPa; the bulk modulus K and its pressure derivative K'were obtained from two fitting forms employed previously in experimental studies of the beta-HMX equation of state. Overall, the results indicate good agreement between the bulk modulus predicted from the measured and calculated compression curves. The bulk modulus determined directly from the elastic tensor of beta-HMX is in significant disagreement with the compression curve-based results. The explanation for this discrepancy is an area of current research.

  3. Elastic Properties of Mantle Minerals

    Science.gov (United States)

    Duffy, T. S.; Stan, C. V.

    2012-12-01

    The most direct information about the interior structure of the Earth comes from seismic wave velocities. Interpretation of seismic data requires an understanding of how sound velocities and elastic properties of minerals vary with pressure, temperature, crystal structure, and composition as well as the role of anelasticity, melts, etc. More generally, elastic moduli are important for understanding many solid-state phenomena including mechanical stability, interatomic interactions, material strength, compressibility, and phase transition mechanisms. The database of mineral elasticity measurements has been growing rapidly in recent years. In this work, we report initial results of an ongoing survey of our current knowledge of mineral elasticity at both ambient conditions and high pressures and temperatures. The analysis is selective, emphasizing single crystal measurements but also incorporating polycrystalline measurements and volume compression data as appropriate. The goal is to synthesize our current understanding of mineral elasticity in terms of structure and composition, and to identify the major remaining needs for experimental and theoretical work. Clinopyroxenes (Cpx) provide an example of our approach. A wide range of clinopyroxene compositions are found geologically and Mg-, Ca-, and Na-rich clinopyroxenes are expected to be important components in the upper mantle. The single-crystal elastic properties of a number of endmember Cpx compositions have been measured and these exhibit a range of ~25% in shear velocity. Those with monovalent cations (spodumene, jadeite) in the M2 site exhibit the highest velocities while Fe-rich (hendenbergit, acmite) compositions have the lowest velocities. The effects on velocity due to a wide range of chemical substitutions can be defined, but there are important discrepancies and omissions in the database. New measurements of omphacites, intermediate diopside-hedenbergite compositions, aegerine/acmite, augite, etc. are

  4. Elastic Properties of Chimpanzee Craniofacial Cortical Bone.

    Science.gov (United States)

    Gharpure, Poorva; Kontogiorgos, Elias D; Opperman, Lynne A; Ross, Callum F; Strait, David S; Smith, Amanda; Pryor, Leslie C; Wang, Qian; Dechow, Paul C

    2016-12-01

    Relatively few assessments of cranial biomechanics formally take into account variation in the material properties of cranial cortical bone. Our aim was to characterize the elastic properties of chimpanzee craniofacial cortical bone and compare these to the elastic properties of dentate human craniofacial cortical bone. From seven cranial regions, 27 cylindrical samples were harvested from each of five chimpanzee crania. Assuming orthotropy, axes of maximum stiffness in the plane of the cortical plate were derived using modified equations of Hooke's law in a Mathcad program. Consistent orientations among individuals were observed in the zygomatic arch and alveolus. The density of cortical bone showed significant regional variation (P  E2  > E1 . Shear moduli were significantly different among regions (P < 0.001). The pattern by which chimpanzee cranial cortical bone varies in elastic properties resembled that seen in humans, perhaps suggesting that the elastic properties of craniofacial bone in fossil hominins can be estimated with at least some degree of confidence. Anat Rec, 299:1718-1733, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Elastic properties of nonstoichiometric reacted PDMS networks

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard; Hansen, Kristoffer Karsten; Sommer-Larsen, Peter

    2003-01-01

    The influence of stoichiometry on the elastic modulus of eight-functional end-linked poly(dimethylsiloxane) (PDMS) networks was investigated by extensional rheometry with extensions up to more than 100%, and the stress-strain relation was found to be almost linear-a characteristic property...

  6. Elastic properties of glasses: a multiscale approach

    Science.gov (United States)

    Rouxel, Tanguy

    2006-12-01

    Very different materials are named 'Glass', with Young's modulus E and Poisson's ratio ν extending from 5 to 180 GPa and from 0.1 to 0.4, respectively, in the case of bulk inorganic glasses. Glasses have in common the lack of long range order in the atomic organization. Beside the essential role of elastic properties for materials selection in mechanical design, we show in this analysis that macroscopical elastic characteristics ( E,ν) provide an interesting way to get insight into the short- and medium-range orders existing in glasses. In particular, ν, the packing density ( C) and the glass network dimensionality appear to be strongly correlated. Networks consisting primarily of chains and layers units (chalcogenides, low Si-content silicate glasses) correspond to ν>0.25 and C>0.56, with maximum values observed for metallic glasses ( ν˜0.4 and C>0.7). On the contrary, νelastic moduli brings a new light on the 'fragility' of glasses (as introduced by Angell) and on the level of cooperativity of atomic movements at the source of the deformation process. To cite this article: T. Rouxel, C. R. Mecanique 334 (2006).

  7. Elastic properties of RCC under flexural loading-experimental and ...

    Indian Academy of Sciences (India)

    The codal provisions recommend elastic properties of concrete and steel and these are fairly accurate enough. ... Another method of determining modulus of elasticity of concrete is by flexural test of a beam specimen. The modulus of elasticity ... The experimental results are verified by using 3D finite element techniques.

  8. Elastic properties of cubic crystals: Every's versus Blackman's diagram

    OpenAIRE

    Paszkiewicz, T.; Wolski, S.

    2007-01-01

    Blackman's diagram of two dimensionless ratios of elastic constants is frequently used to correlate elastic properties of cubic crystals with interatomic bondings. Every's diagram of a different set of two dimensionless variables was used by us for classification of various properties of such crystals. We compare these two ways of characterization of elastic properties of cubic materials and consider the description of various groups of materials, e.g. simple metals, oxides, and alkali halide...

  9. Elastic properties of suspended multilayer WSe2

    Science.gov (United States)

    Zhang, Rui; Koutsos, Vasileios; Cheung, Rebecca

    2016-01-01

    We report the experimental determination of the elastic properties of suspended multilayer WSe2, a promising two-dimensional (2D) semiconducting material combined with high optical quality. The suspended WSe2 membranes have been fabricated by mechanical exfoliation of bulk WSe2 and transfer of the exfoliated multilayer WSe2 flakes onto SiO2/Si substrates pre-patterned with hole arrays. Then, indentation experiments have been performed on these membranes with an atomic force microscope. The results show that the 2D elastic modulus of the multilayer WSe2 membranes increases linearly while the prestress decreases linearly as the number of layers increases. The interlayer interaction in WSe2 has been observed to be strong enough to prevent the interlayer sliding during the indentation experiments. The Young's modulus of multilayer WSe2 (167.3 ± 6.7 GPa) is statistically independent of the thickness of the membranes, whose value is about two thirds of other most investigated 2D semiconducting transition metal dichalcogenides, namely, MoS2 and WS2. Moreover, the multilayer WSe2 can endure ˜12.4 GPa stress and ˜7.3% strain without fracture or mechanical degradation. The 2D WSe2 can be an attractive semiconducting material for application in flexible optoelectronic devices and nano-electromechanical systems.

  10. The elastic properties of fractured rocks

    Science.gov (United States)

    Darcel, C.; Le Goc, R.; Davy, P.

    2013-12-01

    The consequences of fracturing on rock mass strength still remain an issue for rock engineering practices, including excavation or repository design, support design, slope stability and caving in mines. The difficulty is twice and concerns both the description of the fracturing pattern, and the relationship between fracture characteristics and rock mass mechanical properties. This is generally assessed by empirical knowledge but no complete quantitative and theoretical relations are yet established. To our knowledge, the only theoretical work was to found a relationship between the elastic strength and the percolation parameter (i.e. a normalized sum of the cube of fracture radius) for 3D frictionless fracture networks. The relationship has been demonstrated for Poissonian (randomly distributed) low-density (i.e. where fractures are not almost intersecting) networks, with a narrow range of fracture radius. By means of finite-element models and Green's function methods, we extend the analysis to fracture networks with geologically realistic geometry: i.e. non-Poissonian, relatively high densities, and power-law length distributions. The elastic strength of the fractured rock mass is still found to decrease exponentially with the percolation parameter on average. But large deviations from the mean exist for heavy tailed fracture length distribution, i.e. when the probability of having fractures of the order of the system size is no more negligible. We discuss the way to ameliorate the prediction by taking into account configuration details that are not described by statistical parameters.

  11. Modelling the elastic properties of cellulose nanopaper

    DEFF Research Database (Denmark)

    Mao, Rui; Goutianos, Stergios; Tu, Wei

    2017-01-01

    The elastic modulus of cellulose nanopaper was predicted using a two-dimensional (2D) micromechanical fibrous network model. The elastic modulus predicted by the network model was 12 GPa, which is well within the range of experimental data for cellulose nanopapers. The stress state in the network...... revealed both tensile and compressive stresses during elastic deformation of the model. The length, diameter, waviness and elastic modulus of the cellulose nanofibres were varied in the model and their effect on the elastic modulus of fibrous networks was studied. It was found that high values of elastic...... moduli of cellulose networks could be obtained for long, thin and straight nanofibres of high stiffness. The effect of inter-fibre bonding and network density was also investigated. Increasing fibre-fibre interactions facilitated stress transfer in cellulose networks and led to a higher elastic modulus...

  12. Structural phase transition and elastic properties of thorium pnictides ...

    Indian Academy of Sciences (India)

    In the present paper we have pointed out the weaknesses of the approach by Aynyas et al [1] to study the structural phase transition and elastic properties of thorium pnictides. The calculated values of phase transition pressure and other elastic properties using the realistic and actual approach are also given and compared ...

  13. Elastic and microplastic properties of titanium in different structural states

    Science.gov (United States)

    Kardashev, B. K.; Betekhtin, V. I.; Kadomtsev, A. G.; Narykova, M. V.; Kolobov, Yu. R.

    2017-09-01

    The behavior of elastic (Young's modulus) and microplastic properties of titanium depending on the initial structure and subsequent severe plastic deformation that transforms the material (concerning the grain size) into the submicrocrystalline structural state has been studied. It has been shown that, to a great extent, different initial structures of the metal predetermine its elastic properties after deformation.

  14. Elastic Properties of Molecular Glass Thin Films

    Science.gov (United States)

    Torres, Jessica

    2011-12-01

    This dissertation provides a fundamental understanding of the impact of bulk polymer properties on the nanometer length scale modulus. The elastic modulus of amorphous organic thin films is examined using a surface wrinkling technique. Potential correlations between thin film behavior and intrinsic properties such as flexibility and chain length are explored. Thermal properties, glass transition temperature (Tg) and the coefficient of thermal expansion, are examined along with the moduli of these thin films. It is found that the nanometer length scale behavior of flexible polymers correlates to its bulk Tg and not the polymers intrinsic size. It is also found that decreases in the modulus of ultrathin flexible films is not correlated with the observed Tg decrease in films of the same thickness. Techniques to circumvent reductions from bulk modulus were also demonstrated. However, as chain flexibility is reduced the modulus becomes thickness independent down to 10 nm. Similarly for this series minor reductions in T g were obtained. To further understand the impact of the intrinsic size and processing conditions; this wrinkling instability was also utilized to determine the modulus of small organic electronic materials at various deposition conditions. Lastly, this wrinkling instability is exploited for development of poly furfuryl alcohol wrinkles. A two-step wrinkling process is developed via an acid catalyzed polymerization of a drop cast solution of furfuryl alcohol and photo acid generator. The ability to control the surface topology and tune the wrinkle wavelength with processing parameters such as substrate temperature and photo acid generator concentration is also demonstrated. Well-ordered linear, circular, and curvilinear patterns are also obtained by selective ultraviolet exposure and polymerization of the furfuryl alcohol film. As a carbon precursor a thorough understanding of this wrinkling instability can have applications in a wide variety of

  15. Resonant ultrasound spectroscopy: Elastic properties of some intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Chu, F.; Thoma, D.J.; He, Y.; Maloy, S.A.; Mitchell, T.E. [Los Alamos National Lab., NM (United States). Materials Science Technology Div.

    1996-09-01

    A novel nondestructive evaluation method, resonant ultrasound spectroscopy (RUS), is reviewed with an emphasis upon defining the elastic properties of intermetallic phases. The applications and advantages of RUS as compared to other conventional elastic constant measurement methods are explained. RUS has been employed to measure the elastic properties of single crystal and/or polycrystalline intermetallics, such as Laves phases (C15 HfV{sub 2} and NbCr{sub 2}), Nb-modified titanium aluminides, and transition metal disilicides (C11{sub b} MoSi{sub 2}, C40 NbSi{sub 2} and TaSi{sub 2}). For Laves phases, the elastic properties of HfV{sub 2}-based C15 phases show various anomalies and those of C15 NbCr{sub 2} do not. For Nb-modified titanium aluminides, the elastic properties of O-phase alloys are investigated as a function of alloying content. For transition metal disilicides, single crystal elastic constants of MoSi{sub 2}, NbSi{sub 2}, and TaSi{sub 2} are obtained and compared. Based on the experimentally determined elastic properties, the characteristics of interatomic bonding in these materials are examined and the possible impact of the elastic properties on mechanical behavior is discussed.

  16. Elastic properties of fly ash-stabilized mixes

    Directory of Open Access Journals (Sweden)

    Sanja Dimter

    2015-12-01

    Full Text Available Stabilized mixes are used in the construction of bearing layers in asphalt and concrete pavement structures. Two nondestructive methods: resonant frequency method and ultrasonic pulse velocity method, were used for estimation of elastic properties of fly ash–stabilized mixes. Stabilized mixes were designed containing sand from the river Drava and binder composed of different share of cement and fly ash. The aim of the research was to analyze the relationship between the dynamic modulus of elasticity determined by different nondestructive methods. Data showed that average value of elasticity modulus obtained by the ultrasound velocity method is lower than the values of elasticity modulus obtained by resonant frequency method. For further analysis and enhanced discussion of elastic properties of fly ash stabilized mixes, see Dimter et al. [1].

  17. Structural, elastic, optoelectronic and magnetic properties of ...

    Indian Academy of Sciences (India)

    2017-09-22

    Sep 22, 2017 ... (GGA) and Trans-Blaha modified Becke-Johnson potential (TB-mBJ) are used to model the exchange-correlation effects. The computed lattice parameter, internal coordinate and bulk modulus are in good agreement with the existing experimental data. According to the calculated elastic moduli, CdHo2S4 is ...

  18. Imaging of the elastic properties of tissue--a review.

    Science.gov (United States)

    Gao, L; Parker, K J; Lerner, R M; Levinson, S F

    1996-01-01

    Recently, a number of methods have been developed that make it possible to image the elastic properties of soft tissues. Because certain types of tissues such as malignant lesions, for example, have elastic properties that are markedly different from surrounding tissues, elasticity imaging could provide a significant adjunct to current diagnostic ultrasonic methods. Further, elasticity imaging techniques could be used to augment the study of tissues that change their elastic properties, such as skeletal and cardiac muscle. In this paper, we survey some of the previous work done in the related field of biomechanics, and we review measurement techniques from the 1950s to the 1980s. Different approaches to elastic imaging and signal processing are then discussed and a lexicography for elastic imaging is introduced. It is hoped that this nomenclature will provide a meaningful categorization of various approaches and will make evident the inherent parameters displayed and conditions applied in deriving the resulting images. Key assumptions and signal processing approaches are also reviewed. Finally, directions for future work are suggested.

  19. Elastic therapeutic tape: do they have the same material properties?

    Science.gov (United States)

    Boonkerd, Chuanpis; Limroongreungrat, Weerawat

    2016-01-01

    [Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex®, ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight® 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young’s modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young’s modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape. PMID:27190472

  20. Elastic properties of pulmonary artery in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    S. Ya. Dotsenko

    2017-02-01

    Full Text Available Today chronic obstructive pulmonary disease (COPD is one of the most common diseases with specific pulmonary vascular changes. The aim – to evaluate elastic properties of pulmonary artery (PA and pathogenic mechanisms of disorders in COPD. Materials and methods. Participants were 50 patients with COPD stages 1–3 without comorbidities (32 men and 18 women, average age was 49.8 ± 1.0 years. Control group included 30 healthy people (19 men and 11 women, aged 50.1 ± 1.2 years. PA elastic properties was researched by ultrasound method. Statistical analysis was performed by means of the Statistica® 6.0 for Windows (StatSoft Inc. software using parametric and nonparametric methods. Results. Study data showed that pulmonary arterial pressure (PAP and PA elastic properties were significantly different between subjects with COPD and control group. Thus, pulsatility, compliance and distensibility in CORD were decreased (39.23 ± 1.6 %, 6.4 ± 0.4 mm 2/mmHg and 1.71 ± 0.10 %/mmHg versus 51.4 ± 1.9 %, 11.1 ± 0.5 mm 2/mmHg and 3.30 ± 0.12 %/mmHg in control group, respectively, p < 0.05, and elastic modulus and index stiffness B were increased (65.7 ± 3.7 mmHg and 2.91 ± 0.17 to 31.6 ± 1.2 mmHg and 2.05 ± 0.08, versus 31.6 ± 1.2 mm Hg and 2.05 ± 0.08 in control group, respectively, p < 0.05. Analysis in groups divided by severity of COPD showed that PA elastic properties was not different significantly between subjects with COPD stage-1 and control group. However, several significant differences in PAP and PA elastic properties between subjects with COPD stage-2, COPD stage-3 and control group were found (p < 0.05. Pearson correlation analysis was showed significant relationships between indexes of PA elastic properties and FEV1, indexes of PAP. Conclusions. The changes of PA elastic properties in COPD are accompany by increasing stiffness, thus reduce pulsatility, compliance and elasticity of vascular wall. Detected changes of PA elastic

  1. Atomic force microscopy studies on cellular elastic and viscoelastic properties.

    Science.gov (United States)

    Li, Mi; Liu, Lianqing; Xi, Ning; Wang, Yuechao

    2017-06-29

    In this work, a method based on atomic force microscopy (AFM) approach-reside-retract experiments was established to simultaneously quantify the elastic and viscoelastic properties of single cells. First, the elastic and viscoelastic properties of normal breast cells and cancerous breast cells were measured, showing significant differences in Young's modulus and relaxation times between normal and cancerous breast cells. Remarkable differences in cellular topography between normal and cancerous breast cells were also revealed by AFM imaging. Next, the elastic and viscoelasitc properties of three other types of cell lines and primary normal B lymphocytes were measured; results demonstrated the potential of cellular viscoelastic properties in complementing cellular Young's modulus for discerning different states of cells. This research provides a novel way to quantify the mechanical properties of cells by AFM, which allows investigation of the biomechanical behaviors of single cells from multiple aspects.

  2. Local elastic properties of cells studied by SFM

    Science.gov (United States)

    Lekka, M.; Lekki, J.; Marszałek, M.; Golonka, P.; Stachura, Z.; Cleff, B.; Hrynkiewicz, A. Z.

    1999-03-01

    Scanning force microscopy (SFM) can be used in nano-indentation experiments for very soft samples of elastic, organic materials. The present paper describes the methodology of device calibration and Young's moduli determination, to evaluate the elastic properties of living cells in their culture conditions. Two similar lines of normal cells (Hu609) and cancerous ones (T24) were measured. A significant difference in Young's modulus for normal and cancerous cells was detected.

  3. Ultrasound Elasticity Imaging System with Chirp-Coded Excitation for Assessing Biomechanical Properties of Elasticity Phantom

    Directory of Open Access Journals (Sweden)

    Guan-Chun Chun

    2015-12-01

    Full Text Available The biomechanical properties of soft tissues vary with pathological phenomenon. Ultrasound elasticity imaging is a noninvasive method used to analyze the local biomechanical properties of soft tissues in clinical diagnosis. However, the echo signal-to-noise ratio (eSNR is diminished because of the attenuation of ultrasonic energy by soft tissues. Therefore, to improve the quality of elastography, the eSNR and depth of ultrasound penetration must be increased using chirp-coded excitation. Moreover, the low axial resolution of ultrasound images generated by a chirp-coded pulse must be increased using an appropriate compression filter. The main aim of this study is to develop an ultrasound elasticity imaging system with chirp-coded excitation using a Tukey window for assessing the biomechanical properties of soft tissues. In this study, we propose an ultrasound elasticity imaging system equipped with a 7.5-MHz single-element transducer and polymethylpentene compression plate to measure strains in soft tissues. Soft tissue strains were analyzed using cross correlation (CC and absolution difference (AD algorithms. The optimal parameters of CC and AD algorithms used for the ultrasound elasticity imaging system with chirp-coded excitation were determined by measuring the elastographic signal-to-noise ratio (SNRe of a homogeneous phantom. Moreover, chirp-coded excitation and short pulse excitation were used to measure the elasticity properties of the phantom. The elastographic qualities of the tissue-mimicking phantom were assessed in terms of Young’s modulus and elastographic contrast-to-noise ratio (CNRe. The results show that the developed ultrasound elasticity imaging system with chirp-coded excitation modulated by a Tukey window can acquire accurate, high-quality elastography images.

  4. Elastic properties of RCC under flexural loading-experimental and ...

    Indian Academy of Sciences (India)

    plain concrete is taken into consideration whereas effects of reinforcement bars and concrete confined by stirrups are neglected. The aim of study is to determine elastic properties of reinforced cement concrete material. Two important stiffness properties such as AE and EI play important role in analysis of high rise RCC ...

  5. Homogenized Elastic Properties of Graphene for Small Deformations

    Directory of Open Access Journals (Sweden)

    Jurica Sorić

    2013-09-01

    Full Text Available In this paper, we provide the quantification of the linear and non-linear elastic mechanical properties of graphene based upon the judicious combination of molecular mechanics simulation results and homogenization methods. We clarify the influence on computed results by the main model features, such as specimen size, chirality of microstructure, the effect of chosen boundary conditions (imposed displacement versus force and the corresponding plane stress transformation. The proposed approach is capable of explaining the scatter of the results for computed stresses, energy and stiffness and provides the bounds on graphene elastic properties, which are quite important in modeling and simulation of the virtual experiments on graphene-based devices.

  6. Elastic properties of Li+ doped lead zinc borate glasses

    Science.gov (United States)

    Rajaramakrishna, R.; Lakshmikantha, R.; Anavekar, R. V.

    2014-04-01

    Glasses in the system 0.25PbO-(0.25-x) ZnO-0.5B2O3-xLi2O have been prepared by the melt quenching technique. Elastic properties, DSC studies have been employed to study the role of Li2O in the present glass system. Elastic properties and Debye temperature have been determined using pulsed echo ultrasonic interferometer operating at 10MHz. Sound velocities Vl, Vt and elastic moduli decrease up to 5 mol% and then gradually increase with increase in Li2O concentration. Debye temperature and the glass transition temperature decreases with increase in Li2O. Densities remains almost constant up to 15 mol% Li2O concentration and increases monotonically while the molar volume decreases with the increase of Li2O concentration. The results are discussed in view of the borate structural network and dual role of Zn and Pb in these glasses.

  7. Anisotropy in elastic properties of lithium sodium sulphate ...

    Indian Academy of Sciences (India)

    13 = 23, are reported for the first time. The anisotropy in the elastic properties of the crystal are well explained by the pictorial representation of the surface plots of phase velocity, slowness, Young's modulus and linear compressibility in – ...

  8. Elastic and thermodynamic properties of zirconium-and hafnium ...

    Indian Academy of Sciences (India)

    ... Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 41; Issue 1. Elastic and thermodynamic properties of zirconium- and hafnium-doped Rh 3 V intermetallic compounds: potential aerospace material. M MANJULA M SUNDARESWARI E VISWANATHAN. Volume 41 Issue 1 February 2018 Article ID 19 ...

  9. Elastic and thermodynamic properties of zirconium- and hafnium ...

    Indian Academy of Sciences (India)

    2018-02-02

    Feb 2, 2018 ... https://doi.org/10.1007/s12034-017-1537-3. Elastic and thermodynamic properties of zirconium- and hafnium-doped Rh3V intermetallic compounds: potential aerospace material. M MANJULA, M SUNDARESWARI. ∗ and E VISWANATHAN. Department of Physics, Sathyabama University, Chennai 600119, ...

  10. First-principles elastic properties of (alpha)-Pu

    Energy Technology Data Exchange (ETDEWEB)

    Soderlind, P; Klepeis, J E

    2008-11-04

    Density-functional electronic structure calculations have been used to investigate the ambient pressure and low temperature elastic properties of the ground-state {alpha} phase of plutonium metal. The electronic structure and correlation effects are modeled within a fully relativistic anti-ferromagnetic treatment with a generalized gradient approximation for the electron exchange and correlation functionals. The 13 independent elastic constants, for the monoclinic {alpha}-Pu system, are calculated for the observed geometry. A comparison of the results with measured data from resonant ultrasound spectroscopy for a cast sample is made.

  11. Torsional Elastic Property Measurements of Selected Orthodontic Archwires.

    Science.gov (United States)

    1987-01-01

    Triple-Stranded Stainless Steel Wires - Evaluation of Mechanical Properties and Comparison with Titanium Alloy Alternatives. Angle Orthod 57:18-32...Greenberg AR: Effects of Composition and Cross-section on the Elastic Properties of Orthodontic Archwires. Angle Orthod 51:325-341, 1981. S11. Thurow, RC... Orthod 71:565-573, 1977. 14. Wagner JA, Nikolai RJ: Stiffness of Incisor Segments of Edgewise Arches in Torsion and Bending. Angle Orthod 55:37-50, 1985

  12. Elastic properties and electron transport in InAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Migunov, Vadim

    2013-02-22

    The electron transport and elastic properties of InAs nanowires grown by chemical vapor deposition on InAs (001) substrate were studied experimentally, in-situ in a transmission electron microscope (TEM). A TEM holder allowing the measurement of a nanoforce while simultaneous imaging nanowire bending was used. Diffraction images from local areas of the wire were recorded to correlate elastic properties with the atomic structure of the nanowires. Another TEM holder allowing the application of electrical bias between the nanowire and an apex of a metallic needle while simultaneous imaging the nanowire in TEM or performing electron holography was used to detect mechanical vibrations in mechanical study or holographical observation of the nanowire inner potential in the electron transport studies. The combination of the scanning probe methods with TEM allows to correlate the measured electric and elastic properties of the nanowires with direct identification of their atomic structure. It was found that the nanowires have different atomic structures and different stacking fault defect densities that impacts critically on the elastic properties and electric transport. The unique methods, that were applied in this work, allowed to obtain dependencies of resistivity and Young's modulus of left angle 111 right angle -oriented InAs nanowires on defect density and diameter. It was found that the higher is the defect density the higher are the resistivity and the Young's modulus. Regarding the resistivity, it was deduced that the stacking faults increase the scattering of the electrons in the nanowire. These findings are consistent with the literature, however, the effect described by the other groups is not so pronounced. This difference can be attributed to the significant incompleteness of the physical models used for the data analysis. Regarding the elastic modulus, there are several mechanisms affecting the elasticity of the nanowires discussed in the thesis. It

  13. Compressive Strength and Modulus of Elasticity of Concrete with Cubed Waste Tire Rubbers as Coarse Aggregates

    Science.gov (United States)

    Haryanto, Y.; Hermanto, N. I. S.; Pamudji, G.; Wardana, K. P.

    2017-11-01

    One feasible solution to overcome the issue of tire disposal waste is the use of waste tire rubber to replace aggregate in concrete. We have conducted an experimental investigation on the effect of rubber tire waste aggregate in cuboid form on the compressive strength and modulus of elasticity of concrete. The test was performed on 72 cylindrical specimens with the height of 300 mm and diameter of 150 mm. We found that the workability of concrete with waste tire rubber aggregate has increased. The concrete density with waste tire rubber aggregate was decreased, and so was the compressive strength. The decrease of compressive strength is up to 64.34%. If the content of waste tire rubber aggregate is more than 40%, then the resulting concrete cannot be categorized as structural concrete. The modulus of elasticity decreased to 59.77%. The theoretical equation developed to determine the modulus of elasticity of concrete with rubber tire waste aggregate has an accuracy of 84.27%.

  14. Bayesian inference of elastic properties with resonant ultrasound spectroscopy.

    Science.gov (United States)

    Bales, Ben; Petzold, Linda; Goodlet, Brent R; Lenthe, William C; Pollock, Tresa M

    2018-01-01

    Bayesian modeling and Hamiltonian Monte Carlo (HMC) are utilized to formulate a robust algorithm capable of simultaneously estimating anisotropic elastic properties and crystallographic orientation of a specimen from a list of measured resonance frequencies collected via Resonance Ultrasound Spectroscopy (RUS). Unlike typical optimization procedures which yield point estimates of the unknown parameters, computing a Bayesian posterior yields probability distributions for the unknown parameters, and HMC is an efficient way to compute this posterior. The algorithms described are demonstrated on RUS data collected from two parallelepiped specimens of structural metal alloys. First, the elastic constants for a specimen of fine-grain polycrystalline Ti-6Al-4 V with random crystallographic texture and isotropic elastic symmetry are estimated. Second, the elastic constants and crystallographic orientation for a single crystal Ni-based superalloy CMSX-4 specimen are accurately determined, using only measurements of the specimen geometry, mass, and resonance frequencies. The unique contributions of this paper are as follows: the application of HMC for sampling the Bayesian posterior of a probabilistic RUS model, and the procedure for simultaneous estimation of elastic constants and lattice-specimen misorientation. Compared to previous approaches these algorithms demonstrate superior convergence behavior, particularly when the initial parameterization is unknown, and enable substantially simplified experimental procedures.

  15. Elastic properties of ultrathin diamond/AlN membranes

    Energy Technology Data Exchange (ETDEWEB)

    Zuerbig, V., E-mail: verena.zuerbig@iaf-extern.fraunhofer.de [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); IMTEK, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Hees, J.; Pletschen, W.; Sah, R.E.; Wolfer, M.; Kirste, L.; Heidrich, N.; Nebel, C.E. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); Ambacher, O. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany); IMTEK, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Lebedev, V. [Fraunhofer Institute for Applied Solid State Physics IAF, Tullastr. 72, 79108 Freiburg (Germany)

    2014-05-02

    Nanocrystalline diamond- (NCD) and AlN-based ultrathin single layer and bilayer membranes are investigated towards their mechanical properties. It is shown that chemo-mechanical polishing and heavy boron doping of NCD thin films do not impact the elastic properties of NCD layers as revealed by negligible variations of the NCD Young's modulus (E). In addition, it is demonstrated that the combination of NCD elastic layer and AlN piezo-actuator is highly suitable for the fabrication of mechanically stable ultrathin membranes in comparison to AlN single layer membranes. The elastic parameters of NCD/AlN heterostructures are mainly determined by the outstanding high Young's modulus of NCD (E = 1019 ± 19 GPa). Such ultrathin unimorph membranes allow for fabrication of piezo-actuated AlN/NCD microlenses with tunable focus length. - Highlights: • Mechanical properties of nanocrystalline diamond (NCD) and AlN circular membranes • No influence of polishing of NCD thin films on the mechanical properties of NCD • No influence of heavy boron-doping on the mechanical properties of NCD • Demonstration of mechanically stable piezo-actuated NCD/AlN membranes • Reported performance of AlN/NCD microlenses with adjustable focus length.

  16. A micromechanics model of the elastic properties of human dentine

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, J. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Balooch, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marshall, G. W. [Univ. of California, San Francisco, CA (United States). Dept. of Restorative Dentistry; Marshall, S. J. [Univ. of California, San Francisco, CA (United States). Dept. of Restorative Dentistry

    1999-10-01

    A generalized self-consistent model of cylindrical inclusions in a homogeneous and isotropic matrix phase was used to study the effects of tubule orientation on the elastic properties of dentin. Closed form expressions for the five independent elastic constants of dentin were derived in terms of tubule concentration, and the Young's moduli and Poisson ratios of peri- and intertubular dentin. An atomic force microscope (AFM) indentation technique determined the Young's moduli of the peri- and intertubular dentin as approximately 30 GPa and 15 GPa, respectively. Over the natural variation in tubule density found in dentin, there was only a slight variation in the axial and transverse shear moduli with position in the tooth, and there was no measurable effect of tubule orientation. We conclude that tubule orientation has no appreciable effect on the elastic behavior of normal dentin, and that the elastic properties of healthy dentin can be modeled as an isotropic continuum with a Young's modulus of approximately 16 GPa and a shear modulus of 6.2 GPa.

  17. ELASTIC PROPERTIES OF SILICA POLYMORPHS – A REVIEW

    Directory of Open Access Journals (Sweden)

    Pabst W.

    2013-09-01

    Full Text Available The elastic properties of silica phases are reviewed. Available monocrystal data for crystalline SiO2 polymorphs (low-quartz, high-quartz, low-cristobalite, high-cristobalite, stishovite are collected from the literature, and effective elastic constants (Young’s moduli, shear moduli, bulk moduli and Poisson ratios are calculated from these using Voigt-Reuss-Hill averaging. Both experimental data and simulation results are taken into account. A table of room temperature elastic constants for crystalline silica polymorphs and silica glass is given that lists the recommended current “state-of-the-art“ values. All data are consistent with the well-known auxetic behavior of cristobalite at room temperature, and high-temperature simulation data published for cristobalite confirm auxetic behavior for all temperatures from room temperature up to more than 1500°C. The calculations of this paper show that also quartz can be auxetic, but only in a very limited temperature range around the low-to-high-quartz transition temperature (420 – 577°C. Experimental measurements of elastic properties of tridymite and cristobalite, including high-temperature measurements, are identified as a desideratum of future research.

  18. Structural, elastic, electronic and optical properties of bi-alkali ...

    Indian Academy of Sciences (India)

    The structural parameters, elastic constants, electronic and optical properties of the bi-alkali antimonides (Na 2 KSb, Na 2 RbSb, Na 2 CsSb, K 2 RbSb, K 2 CsSb and Rb 2 CsSb) were calculated using state-of-the-art density functional theory. Different exchange-correlation potentials were adopted to predict the physical ...

  19. Evaluation of the elastic properties of monovalent oxides using ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... Indian Academy of Sciences. DOI 10.1007/s12034-017-1409-x. Evaluation of the elastic properties of monovalent oxides using. TeO2-based glasses. A M EMARA1,2, S F MANSOUR1, M Y HASSAAN3 and El SAYED YOUSEF2,4,∗. 1Faculty of Science, Department of Physics, Zagazig University, Zagazig, ...

  20. Liquid Crystals Viscous and Elastic Properties in Theory and Applications

    CERN Document Server

    Pasechnik, Sergey V; Shmeliova, Dina V

    2009-01-01

    Covering numerous practical applications as yet not covered in any single source of information, this monograph discusses the importance of viscous and elastic properties for applications in both display and non-display technologies. The very well-known authors are major players in this field of research and pay special attention here to the use of liquid crystals in fiber optic devices as applied in telecommunication circuits.

  1. Elastic properties of cubic crystals: Every's versus Blackman's diagram

    Science.gov (United States)

    Paszkiewicz, T.; Wolski, S.

    2008-03-01

    Blackman's diagram of two dimensionless ratios of elastic constants is frequently used to correlate elastic properties of cubic crystals with interatomic bondings. Every's diagram of a different set of two dimensionless variables was used by us for classification of various properties of such crystals. We compare these two ways of characterization of elastic properties of cubic materials and consider the description of various groups of materials, e.g. simple metals, oxides, and alkali halides. With exception of intermediate valent compounds, the correlation coefficients for Every's diagrams of various groups of materials are greater than for Blackaman's diagrams, revealing the existence of a linear relationship between two dimensionless Every's variables. Alignment of elements and compounds along lines of constant Poisson's ratio v(lang100rang, m), (m arbitrary perpendicular to lang100rang) is observed. Division of the stability region in Blackman's diagram into region of complete auxetics, auxetics and non-auxetics is introduced. Correlations of a scaling and an acoustic anisotropy parameter are considered.

  2. Elastic Properties and Enhanced Piezoelectric Response at Morphotropic Phase Boundaries

    Science.gov (United States)

    Cordero, Francesco

    2015-01-01

    The search for improved piezoelectric materials is based on the morphotropic phase boundaries (MPB) between ferroelectric phases with different crystal symmetry and available directions for the spontaneous polarization. Such regions of the composition x−T phase diagrams provide the conditions for minimal anisotropy with respect to the direction of the polarization, so that the polarization can easily rotate maintaining a substantial magnitude, while the near verticality of the TMPBx boundary extends the temperature range of the resulting enhanced piezoelectricity. Another consequence of the quasi-isotropy of the free energy is a reduction of the domain walls energies, with consequent formation of domain structures down to nanoscale. Disentangling the extrinsic and intrinsic contributions to the piezoelectricity in such conditions requires a high level of sophistication from the techniques and analyses for studying the structural, ferroelectric and dielectric properties. The elastic characterization is extremely useful in clarifying the phenomenology and mechanisms related to ferroelectric MPBs. The relationship between dielectric, elastic and piezoelectric responses is introduced in terms of relaxation of defects with electric dipole and elastic quadrupole, and extended to the response near phase transitions in the framework of the Landau theory. An account is provided of the anelastic experiments, from torsional pendulum to Brillouin scattering, that provided new important information on ferroelectric MPBs, including PZT, PMN-PT, NBT-BT, BCTZ, and KNN-based systems. PMID:28793707

  3. Elastic Properties and Enhanced Piezoelectric Response at Morphotropic Phase Boundaries

    Directory of Open Access Journals (Sweden)

    Francesco Cordero

    2015-12-01

    Full Text Available The search for improved piezoelectric materials is based on the morphotropic phase boundaries (MPB between ferroelectric phases with different crystal symmetry and available directions for the spontaneous polarization. Such regions of the composition x − T phase diagrams provide the conditions for minimal anisotropy with respect to the direction of the polarization, so that the polarization can easily rotate maintaining a substantial magnitude, while the near verticality of the TMPB(x boundary extends the temperature range of the resulting enhanced piezoelectricity. Another consequence of the quasi-isotropy of the free energy is a reduction of the domain walls energies, with consequent formation of domain structures down to nanoscale. Disentangling the extrinsic and intrinsic contributions to the piezoelectricity in such conditions requires a high level of sophistication from the techniques and analyses for studying the structural, ferroelectric and dielectric properties. The elastic characterization is extremely useful in clarifying the phenomenology and mechanisms related to ferroelectric MPBs. The relationship between dielectric, elastic and piezoelectric responses is introduced in terms of relaxation of defects with electric dipole and elastic quadrupole, and extended to the response near phase transitions in the framework of the Landau theory. An account is provided of the anelastic experiments, from torsional pendulum to Brillouin scattering, that provided new important information on ferroelectric MPBs, including PZT, PMN-PT, NBT-BT, BCTZ, and KNN-based systems.

  4. Hardrock Elastic Physical Properties: Birch's Seismic Parameter Revisited

    Science.gov (United States)

    Wu, M.; Milkereit, B.

    2014-12-01

    Identifying rock composition and properties is imperative in a variety of fields including geotechnical engineering, mining, and petroleum exploration, in order to accurately make any petrophysical calculations. Density is, in particular, an important parameter that allows us to differentiate between lithologies and estimate or calculate other petrophysical properties. It is well established that compressional and shear wave velocities of common crystalline rocks increase with increasing densities (i.e. the Birch and Nafe-Drake relationships). Conventional empirical relations do not take into account S-wave velocity. Physical properties of Fe-oxides and massive sulfides, however, differ significantly from the empirical velocity-density relationships. Currently, acquiring in-situ density data is challenging and problematic, and therefore, developing an approximation for density based on seismic wave velocity and elastic moduli would be beneficial. With the goal of finding other possible or better relationships between density and the elastic moduli, a database of density, P-wave velocity, S-wave velocity, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio was compiled based on a multitude of lab samples. The database is comprised of isotropic, non-porous metamorphic rock. Multi-parameter cross plots of the various elastic parameters have been analyzed in order to find a suitable parameter combination that reduces high density outliers. As expected, the P-wave velocity to S-wave velocity ratios show no correlation with density. However, Birch's seismic parameter, along with the bulk modulus, shows promise in providing a link between observed compressional and shear wave velocities and rock densities, including massive sulfides and Fe-oxides.

  5. Elastic and piezoresistive properties of nickel carbides from first principles

    Science.gov (United States)

    Kelling, Jeffrey; Zahn, Peter; Schuster, Jörg; Gemming, Sibylle

    2017-01-01

    The nickel-carbon system has received increased attention over the past years due to the relevance of nickel as a catalyst for carbon nanotube and graphene growth, where nickel carbide intermediates may be involved or carbide interface layers form in the end. Nickel-carbon composite thin films comprising Ni3C are especially interesting in mechanical sensing applications. Due to the metastability of nickel carbides, formation conditions and the coupling between mechanical and electrical properties are not yet well understood. Using first-principles electronic structure methods, we calculated the elastic properties of Ni3C ,Ni2C , and NiC , as well as changes in electronic properties under mechanical strain. We observe that the electronic density of states around the Fermi level does not change under the considered strains of up to 1%, which correspond to stresses up to 3 GPa . Relative changes in conductivity of Ni3C range up to maximum values of about 10%.

  6. Elastic Properties of Hybrid Graphene/Boron Nitride Monolayer

    OpenAIRE

    Peng, Qing; Zamiri, Amir R.; Ji, Wei; De, Suvranu

    2011-01-01

    Recently hybridized monolayers consisting of hexagonal boron nitride (h-BN) phases inside graphene layer have been synthesized and shown to be an effective way of opening band gap in graphene monolayers [1]. In this letter, we report an ab initio density functional theory (DFT)- based study of h-BN domain size effect on the elastic properties of graphene/boron nitride hybrid monolayers (h-BNC). We found both inplane stiffness and longitudinal sound velocity of h-BNC linearly decrease with h-B...

  7. The Effect of Interfacial Transition Zone Properties on the Elastic Properties of Cementitious Nanocomposite Materials

    Directory of Open Access Journals (Sweden)

    Ala G. Abu Taqa

    2015-01-01

    Full Text Available A parametric study was conducted to explore the effect of the interfacial transition zone (ITZ or interphase on the overall elastic modulus of the CNT-reinforced cement. The effect of the ITZ properties on the elastic modulus of the CNT-reinforced cement was investigated using a four-phase axisymmetric model consisting of a single CNT aligned at the center of composite unit cell, an interface, an ITZ (or interphase, and a cement matrix. The CNT and cement matrix were assumed fully elastic while the interface was modeled using a cohesive surface framework. The width and mechanical properties of the ITZ and the interface were found to affect significantly the elastic modulus and the behavior of the composite material.

  8. Phase stability and elastic properties of Cr-V alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gao, M C; Suzuki, Y; Schweiger, H; Doğan, Ö N; Hawk, J; Widom, M

    2013-01-23

    V is the only element in the periodic table that forms a complete solid solution with Cr and thus is particularly important in alloying strategy to ductilize Cr. This study combines first-principles density functional theory calculations and experiments to investigate the phase stability and elastic properties of Cr–V binary alloys. The cluster expansion study reveals the formation of various ordered compounds at low temperatures that were not previously known. These compounds become unstable due to the configurational entropy of bcc solid solution as the temperature is increased. The elastic constants of ordered and disordered compounds are calculated at both T = 0 K and finite temperatures. The overall trends in elastic properties are in agreement with measurements using the resonant ultrasound spectroscopy method. The calculations predict that addition of V to Cr decreases both the bulk modulus and the shear modulus, and enhances the Poisson’s ratio, in agreement with experiments. Decrease in the bulk modulus is correlated to decrease in the valence electron density and increase in the lattice constant. An enhanced Poisson’s ratio for bcc Cr–V alloys (compared to pure Cr) is associated with an increased density of states at the Fermi level. Furthermore, the difference charge density in the bonding region in the (110) slip plane is highest for pure Cr and decreases gradually as V is added. The present calculation also predicts a negative Cauchy pressure for pure Cr, and it becomes positive upon alloying with V. The intrinsic ductilizing effect from V may contribute, at least partially, to the experimentally observed ductilizing phenomenon in the literature.

  9. Stress effects on the elastic properties of amorphous polymeric materials

    Energy Technology Data Exchange (ETDEWEB)

    Caponi, S., E-mail: silvia.caponi@cnr.it, E-mail: silvia.corezzi@unipg.it [Istituto Officina dei Materiali del CNR (CNR-IOM) - Unità di Perugia, c/o Dipartimento di Fisica e Geologia, Perugia I-06100 (Italy); Corezzi, S., E-mail: silvia.caponi@cnr.it, E-mail: silvia.corezzi@unipg.it [Dipartimento di Fisica e Geologia, Università di Perugia, Via A. Pascoli, I-06100 Perugia (Italy); CNR-ISC (Istituto dei Sistemi Complessi), c/o Università di Roma “LaSapienza,” Piazzale A. Moro 2, I-00185 Roma (Italy); Mattarelli, M. [NiPS Laboratory, Dipartimento di Fisica e Geologia, Università di Perugia, Via A. Pascoli, I-06100 Perugia (Italy); Fioretto, D. [Dipartimento di Fisica e Geologia, Università di Perugia, Via A. Pascoli, I-06100 Perugia (Italy)

    2014-12-07

    Brillouin light scattering measurements have been used to study the stress induced modification in the elastic properties of two glass forming polymers: polybutadiene and epoxy-amine resin, prototypes of linear and network polymers, respectively. Following the usual thermodynamic path to the glass transition, polybutadiene has been studied as a function of temperature from the liquid well into the glassy phase. In the epoxy resin, the experiments took advantage of the system ability to reach the glass both via the chemical vitrification route, i.e., by increasing the number of covalent bonds among the constituent molecules, as well as via the physical thermal route, i.e., by decreasing the temperature. Independently from the particular way chosen to reach the glassy phase, the measurements reveal the signature of long range tensile stresses development in the glass. The stress presence modifies both the value of the sound velocities and their mutual relationship, so as to break the generalized Cauchy-like relation. In particular, when long range stresses, by improvise sample cracking, are released, the frequency of longitudinal acoustic modes increases more than 10% in polybutadiene and ∼4% in the epoxy resin. The data analysis suggests the presence of at least two different mechanisms acting on different length scales which strongly affect the overall elastic behaviour of the systems: (i) the development of tensile stress acting as a negative pressure and (ii) the development of anisotropy which increases its importance deeper and deeper in the glassy state.

  10. Engineering properties for high kitchen waste content municipal solid waste

    Directory of Open Access Journals (Sweden)

    Wu Gao

    2015-12-01

    Full Text Available Engineering properties of municipal solid waste (MSW depend largely on the waste's initial composition and degree of degradation. MSWs in developing countries usually have a high kitchen waste content (called HKWC MSW. After comparing and analyzing the laboratory and field test results of physical composition, hydraulic properties, gas generation and gas permeability, and mechanical properties for HKWC MSW and low kitchen waste content MSW (called LKWC MSW, the following findings were obtained: (1 HKWC MSW has a higher initial water content (IWC than LKWC MSW, but the field capacities of decomposed HKWC and LKWC MSWs are similar; (2 the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW; (3 compared with LKWC MSW, HKWC MSW has a higher landfill gas (LFG generation rate but a shorter duration and a lower potential capacity; (4 the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW, but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW; and (5 the shear strength of HKWC MSW changes significantly with time and strain. Based on the differences of engineering properties between these two kinds of MSWs, the geo-environmental issues in HKWC MSW landfills were analyzed, including high leachate production, high leachate mounds, low LFG collection efficiency, large settlement and slope stability problem, and corresponding advice for the management and design of HKWC MSW landfills was recommended.

  11. Anisotropy in elastic properties of lithium sodium sulphate ...

    Indian Academy of Sciences (India)

    Administrator

    velocities in these crystals in the specified directions are tabulated in table 1. The values of the elastic constants, compliance constants and Poisson's ratios of LSSW grown at 323K are tabulated in table 2. The elastic con- stants C12, C13, C14 and C66 are evaluated from the combi- nation of other elastic constants, with the ...

  12. Elastic properties of noncarbon nanotubes as compared to carbon nanotubes

    Science.gov (United States)

    Kochaev, Aleksey

    2017-10-01

    A comparative study of stability, structural, and elastic properties of single-wall noncarbon nanotubes, including BN, AlN, GaN, AlP, GaP, and B nanotubes using ab initio simulation is presented. The proposed nanotubes can be found in nature, which is confirmed by calculation of their binding energy. The values of Young's modulus and Poisson's ratio for (0,n ) and (n ,n ) proposed nanotubes with n =3 ⋯20 are obtained. The conception of two-dimensional (2D) Young's modulus of planar and tubular materials was developed. The calculations show that stable forms of boron nitride nanotubes have the 2D Young's modulus almost similar to carbon nanotubes. At the same time, it is stated that boron nanotubes have a higher 2D Young's modulus than any other known carbon and noncarbon nanostructures.

  13. Elastic and transport properties of topological semimetal ZrTe

    Science.gov (United States)

    Guo, San-Dong; Wang, Yue-Hua; Lu, Wan-Li

    2017-11-01

    Topological semimetals may have substantial applications in electronics, spintronics, and quantum computation. Recently, ZrTe was predicted as a new type of topological semimetal due to the coexistence of Weyl fermions and massless triply degenerate nodal points. In this work, the elastic and transport properties of ZrTe are investigated by combining the first-principles calculations and semiclassical Boltzmann transport theory. Calculated elastic constants prove the mechanical stability of ZrTe, and the bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio also are calculated. It is found that spin–orbit coupling (SOC) has slightly enhanced effects on the Seebeck coefficient, which along the a(b) and c directions for pristine ZrTe at 300 K is 46.26 μVK‑1 and 80.20 μVK‑1, respectively. By comparing the experimental electrical conductivity of ZrTe (300 K) with the calculated value, the scattering time is determined as 1.59 × 10‑14 s. The predicted room-temperature electronic thermal conductivity along the a(b) and c directions is 2.37 {{Wm}}-1{{{K}}}-1 and 2.90 {{Wm}}-1{{{K}}}-1, respectively. The room-temperature lattice thermal conductivity is predicted as 17.56 {{Wm}}-1{{{K}}}-1 and 43.08 {{Wm}}-1{{{K}}}-1 along the a(b) and c directions, showing very strong anisotropy. Calculated results show that isotope scattering produces an observable effect on lattice thermal conductivity. To observably reduce lattice thermal conductivity by nanostructures, the characteristic length should be smaller than 70 nm, based on cumulative lattice thermal conductivity with respect to the phonon mean free path (MFP) at 300 K. It is noted that the average room-temperature lattice thermal conductivity of ZrTe is slightly higher than that of isostructural MoP, which is due to larger phonon lifetimes and smaller Grüneisen parameters. Finally, the total thermal conductivity as a function of temperature is predicted for pristine ZrTe. Our works provide valuable

  14. The Effect of Fiber Geometry and Interfacial Properties on the Elastic Properties of Cementitious Nanocomposite Material

    Directory of Open Access Journals (Sweden)

    Ala G. Abu Taqa

    2015-01-01

    Full Text Available This paper investigates the elastic (Young’s modulus of carbon Nanotube- (CNT- reinforced cement paste using 3D and axisymmetric models using Abaqus software. The behavior of the CNT and the cement matrix was assumed to be fully elastic while the cohesive surface framework was used to model the interface. To investigate the effect of fiber waviness on the value of the elastic modulus, 3D models were developed assuming different distributions of fibers. The results obtained using the 3D model were compared to those obtained using the simplified three-phase axisymmetric model which consists of one single CNT aligned in the center of composite unit cell, an interface, and cement matrix. A parametric study was then carried out using the axisymmetric model to study the role of the interface in the composite elastic modulus without accounting for the presence of the interfacial transition zone (ITZ or interphase. The results showed that the CNTs waviness significantly reduced their reinforcing capability in the cement paste. On the other hand, the results obtained using the axisymmetric model were found to be in good agreement with those obtained using the 3D model. Moreover, the results of the parametric study showed that the interface properties significantly affect the composite elastic modulus and alter its behavior.

  15. Elastic properties of boron carbide films via surface acoustic waves measured by Brillouin light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Salas, E.; Jimenez-Villacorta, F.; Jimenez Rioboo, R.J.; Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Sanchez-Marcos, J. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Munoz-Martin, A.; Prieto, J.E.; Joco, V. [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2013-03-15

    Surface acoustic wave (SAW) velocity has been determined by high resolution Brillouin light scattering to study the mechano-elastic properties of boron carbide films prepared by radio frequency (RF) sputtering. The comparison of experimentally observed elastic behaviour with simulations made by considering film composition obtained from elastic recoil detection analysis-time of flight (ERDA-ToF) spectroscopy allows establishing that elastic properties are determined by that of crystalline boron carbide with a lessening of the SAW velocity values due to surface oxidation. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Simulation of Elastic Properties of Polymer- Clay Nanocomposite

    Directory of Open Access Journals (Sweden)

    M.R. Dashtbayazi

    2015-12-01

    Full Text Available In this research, stiffness of polymer-clay nanocomposites was simulated by Mori-Tanaka and two and three dimensional finite element models. Nanoclays were dispersed into polymer matrix in two ways, namely parallel and random orientations toward loading direction. Effects of microstructural parameters including volume fraction of nanoclays, elastic modulus of nanoclays and interphase, thickness of interphase, aspect ratio of nanoclays and random orientation of nanoclays on elastic modulus of the nanocomposite were investigated by finite element model. Comparing the simulation with experimental results showed that the Mori-Tanak simulation results were closer to the experimental results. Analysis of results showed that the volume fraction of nanoclay, elastic modulus of nanoclay, deviation of nanoclay layers with respect to loading direction, nanoclays aspect ratio, thickness of interphase and the elastic modulus of interphase had respectively the most to the least effect on elastic modulus of nanocomposite.

  17. Microstructure, elastic and electromagnetic properties of epoxy-graphite composites

    Science.gov (United States)

    Bellucci, S.; Micciulla, F.; Levin, V. M.; Petronyuk, Yu. S.; Chernozatonskii, L. A.; Kuzhir, P. P.; Paddubskaya, A. G.; Macutkevic, J.; Pletnev, M. A.; Fierro, V.; Celzard, A.

    2015-06-01

    A set of epoxy resin-based composites filled with 0.25 - 2.0 wt.% of commercially available exfoliated graphite (EG) and thick graphene (TG), prepared by suspending EG particles in cyclohexane, and submitting the suspension to a series of grinding and ultrasonic dispersion steps, was produced. The microstructure of such epoxy-graphite composites has been studied by the impulse acoustic microscopy technique. According to acoustic microscopy data, exfoliated graphite microparticles have been well dispersed in the epoxy matrix. TG nanoflakes demonstrated persistent tendency to clustering and formation of agglomerates. The addition of graphite particles in small amount (0.25 - 2.0 wt.%) did not influence the bulk elastic properties of epoxy-graphite composite materials. Being extremely lightweight, 0.003 g cm-3, EG had a lower percolation threshold than TG, at the level of 1-1.5 wt.% against 2.1-3.2 wt.%, respectively. As a result, epoxy composites filled with 1.0-2.0 wt.% EG provided high electromagnetic (EM) interference shielding both at microwave and THz frequencies. In contrast, no significant influence of TG loading was observed at low weight fraction (up to 2 wt.%) on the EM performance of epoxy composites.

  18. Elastic, micro- and macroplastic properties of polycrystalline beryllium

    Science.gov (United States)

    Kardashev, B. K.; Kupriyanov, I. B.

    2011-12-01

    The Young's modulus and the internal friction of beryllium polycrystals (size grain from 6 to 60 μm) prepared by the powder metallurgy method have been studied as functions of the amplitude and temperature in the range from 100 to 873 K. The measurements have been performed using the composite piezoelectric vibrator method for longitudinal vibrations at frequencies about 100 kHz. Based on the acoustic measurements, the data have been obtained on the elastic and inelastic (microplastic) properties as functions of vibration stress amplitudes within the limits from 0.2 to 30-60 MPa. The microplastic deformation diagram is shown to become nonlinear at the amplitudes higher than 5 MPa. The beryllium mechanical characteristics (the yield strength σ 0.2, the ultimate strength σ u , and the conventional microscopic yield strength σ y ) obtained with various grain sizes are compared. At room temperature, all the parameters satisfactorily obey the Hall-Petch relationship, although there is no complete similarity. The temperature dependences are quite different, namely: σ 0.2( T) and σ u ( T) decrease monotonically during heating from room temperature to higher temperatures; however, σ y ( T) behaves unusually, and it has a minimum near 400 K. The different levels of stresses and the absence of similarity indicate that the scattering of the ultrasound energy and the formation of a level of the macroscopic flow stresses in beryllium occur on dislocation motion obstacles of different origins.

  19. Structure–mechanics property relationship of waste derived biochars

    Energy Technology Data Exchange (ETDEWEB)

    Das, Oisik, E-mail: odas566@aucklanduni.ac.nz [Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142 (New Zealand); Sarmah, Ajit K., E-mail: a.sarmah@auckland.ac.nz [Department of Civil and Environmental Engineering, University of Auckland, Auckland 1142 (New Zealand); Bhattacharyya, Debes, E-mail: d.bhattacharyya@auckland.ac.nz [Department of Mechanical Engineering, Center for Advanced Composite Materials, University of Auckland, Auckland 1142 (New Zealand)

    2015-12-15

    The widespread applications of biochar in agriculture and environmental remediation made the scientific community ignore its mechanical properties. Hence, to examine the scope of biochar's structural applications, its mechanical properties have been investigated in this paper through nanoindentation technique. Seven waste derived biochars, made under different pyrolysis conditions and from diverse feedstocks, were studied via nanoindentation, infrared spectroscopy, X–ray crystallography, thermogravimetry, and electron microscopy. Following this, an attempt was made to correlate the biochars' hardness/modulus with reaction conditions and their chemical properties. The pine wood biochar made at 900 °C and 60 min residence time was found to have the highest hardness and elastic modulus of 4.29 and 25.01 GPa, respectively. It was shown that a combination of higher heat treatment (≥ 500 °C) temperature and longer residence time (~ 60 min) increases the values of hardness and modulus. It was further realized that pyrolysis temperature was a more dominant factor than residence time in determining the final mechanical properties of biochar particles. The degree of aromaticity and crystallinity of the biochar were also correlated with higher values of hardness and modulus. - Highlights: • Characterization was done on waste based biochars which included nanoindentation. • Pine saw dust biochar made at 900 °C for 60 min had highest hardness/modulus. • Combination of temperature/residence time affect biochar's mechanical propertie.s • Aromaticity and crystallinity positively affected biochar's mechanical properties.

  20. Attenuation of elastic waves in bentonite and monitoring of radioactive waste repositories

    Science.gov (United States)

    Biryukov, A.; Tisato, N.; Grasselli, G.

    2016-04-01

    Deep geological repositories, isolated from the geosphere by an engineered bentonite barrier, are currently considered the safest solution for high-level radioactive waste (HLRW) disposal. As the physical conditions and properties of the bentonite barrier are anticipated to change with time, seismic tomography was suggested as a viable technique to monitor the physical state and integrity of the barrier and to timely detect any unforeseen failure. To do so, the seismic monitoring system needs to be optimized, and this can be achieved by conducting numerical simulations of wave propagation in the repository geometry. Previous studies treated bentonite as an elastic medium, whereas recent experimental investigations indicate its pronounced viscoelastic behaviour. The aims of this contribution are (i) to numerically estimate the effective attenuation of bentonite as a function of temperature T and water content Wc, so that synthetic data can accurately reproduce experimental traces and (ii) assess the feasibility and limitation of the HLRW repository monitoring by simulating the propagation of sonic waves in a realistic repository geometry. A finite difference method was utilized to simulate the wave propagation in experimental and repository setups. First, the input of the viscoelastic model was varied to achieve a match between experimental and numerical traces. The routine was repeated for several values of Wc and T, so that quality factors Qp(Wc, T) and Qs(Wc, T) were obtained. Then, the full-scale monitoring procedure was simulated for six scenarios, representing the evolution of bentonite's physical state. The estimated Qp and Qs exhibited a minimum at Wc = 20 per cent and higher sensitivity to Wc, rather than T, suggesting that pronounced inelasticity of the clay has to be taken into account in geophysical modelling and analysis. The repository-model traces confirm that active seismic monitoring is, in principle, capable of depicting physical changes in the

  1. Thermal properties of simulated Hanford waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P. [Pacific Northwest National Laboratory, Richland Washington USA; Chun, Jaehun [Pacific Northwest National Laboratory, Richland Washington USA; Crum, Jarrod V. [Pacific Northwest National Laboratory, Richland Washington USA; Canfield, Nathan L. [Pacific Northwest National Laboratory, Richland Washington USA; Rönnebro, Ewa C. E. [Pacific Northwest National Laboratory, Richland Washington USA; Vienna, John D. [Pacific Northwest National Laboratory, Richland Washington USA; Kruger, Albert A. [U.S. Department of Energy, Office of River Protection, Richland Washington

    2017-03-20

    The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will vitrify the mixed hazardous wastes generated from 45 years of plutonium production. The molten glasses will be poured into stainless steel containers or canisters and subsequently quenched for storage and disposal. Such highly energy-consuming processes require precise thermal properties of materials for appropriate facility design and operations. Key thermal properties (heat capacity, thermal diffusivity, and thermal conductivity) of representative high-level and low-activity waste glasses were studied as functions of temperature in the range of 200 to 800°C (relevant to the cooling process), implementing simultaneous differential scanning calorimetry-thermal gravimetry (DSC-TGA), Xe-flash diffusivity, pycnometry, and dilatometry. The study showed that simultaneous DSC-TGA would be a reliable method to obtain heat capacity of various glasses at the temperature of interest. Accurate thermal properties from this study were shown to provide a more realistic guideline for capacity and time constraint of heat removal process, in comparison to the design basis conservative engineering estimates. The estimates, though useful for design in the absence measured physical properties, can now be supplanted and the measured thermal properties can be used in design verification activities.

  2. Simulation of Elastic Properties of Polymer- Clay Nanocomposite

    OpenAIRE

    M.R. Dashtbayazi; M. Mahmoudi Meymand

    2015-01-01

    In this research, stiffness of polymer-clay nanocomposites was simulated by Mori-Tanaka and two and three dimensional finite element models. Nanoclays were dispersed into polymer matrix in two ways, namely parallel and random orientations toward loading direction. Effects of microstructural parameters including volume fraction of nanoclays, elastic modulus of nanoclays and interphase, thickness of interphase, aspect ratio of nanoclays and random orientation of nanoclays on elastic modulus of ...

  3. Elastic properties and spectroscopic studies of Na2O–ZnO–B2O3 ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Elastic properties, 11B MAS–NMR and IR spectroscopic studies have been employed to study the structure of Na2O–ZnO–B2O3 glasses. Sound velocities and elastic moduli such as longitudinal, Young's, bulk and shear modulus have been measured at a frequency of 10 MHz as a function of ZnO concentration.

  4. Elastic properties of surfactant monolayers at liquid-liquid interfaces: A molecular dynamics study

    DEFF Research Database (Denmark)

    Laradji, Mohamed; Mouritsen, Ole G.

    2000-01-01

    Using a simple molecular model based on the Lennard-Jones potential, we systematically study the elastic properties of liquid-liquid interfaces containing surfactant molecules by means of extensive and large-scale molecular dynamics simulations. The main elastic constants of the interface, corres...

  5. Rational design of soft mechanical metamaterials: Independent tailoring of elastic properties with randomness

    Science.gov (United States)

    Mirzaali, M. J.; Hedayati, R.; Vena, P.; Vergani, L.; Strano, M.; Zadpoor, A. A.

    2017-07-01

    The elastic properties of mechanical metamaterials are direct functions of their topological designs. Rational design approaches based on computational models could, therefore, be used to devise topological designs that result in the desired properties. It is of particular importance to independently tailor the elastic modulus and Poisson's ratio of metamaterials. Here, we present patterned randomness as a strategy for independent tailoring of both properties. Soft mechanical metamaterials incorporating various types of patterned randomness were fabricated using an indirect additive manufacturing technique and mechanically tested. Computational models were also developed to predict the topology-property relationship in a wide range of proposed topologies. The results of this study show that patterned randomness allows for independent tailoring of the elastic properties and covering a broad area of the elastic modulus-Poisson's ratio plane. The uniform and homogenous topologies constitute the boundaries of the covered area, while topological designs with patterned randomness fill the enclosed area.

  6. Effects of Condylar Elastic Properties to Temporomandibular Joint Stress

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2009-01-01

    Full Text Available Mandibular condyle plays an important role in the growth and reconstruction of the temporomandibular joint (TMJ. We aimed to obtain orthotropic elastic parameters of the condyle using a continuous-wave ultrasonic technique and to observe the effects of condylar elastic parameters on stress distribution of the TMJ using finite element analysis (FEA. Using the ultrasonic technique, all nine elastic parameters were obtained, which showed that the mandibular condyle was orthotropic. With the condyle defined as orthotropic, the occlusal stress was transferred fluently and uniformly from the mandible to the TMJ. The stress distribution in the isotropic model showed stepped variation among different anatomical structures with higher stress values in the cartilage and condyle than in the orthotropic model. We conclude that anisotropy has subtle yet significant effects on stress distribution of the TMJ and could improve the reality of simulations.

  7. To the theory of shear elastic properties of magnetic gels

    Science.gov (United States)

    Lopez-Lopez, M. T.; Iskakova, L. Yu.; Zubarev, A. Yu.

    2017-11-01

    We present results of theoretical study of elastic shear modulus of magnetic gels, consisting of single non Brownian magnetic particles, homogeneously (gas-like) distributed in an elastic matrix. The composite is placed in magnetic field, perpendicular to the direction of the sample shear. Effect of both, magnetically hard and soft particles is studied. In order to get mathematically rigorous results, we have restricted ourselves by the analysis of the composites with low concentration of the particles and neglected any interactions between them. Only small deformations of the system were considered. Analysis shows that effect of magnetic field on the macroscopic (measurable) shear modulus of the composite can be comparable with that, provided by the presence of the rigid inclusions in the elastic matrix. The suggested asymptotic model can be a robust background for the study of the systems with moderate or high concentration of the particles.

  8. Detection of change in elastic properties of a stretched DNA by using correlation functions of fluctuations

    Science.gov (United States)

    Murayama, Yoshihiro; Yogiashi, Yusuke; Iwamoto, Takuya; Mitsuhashi, Yoshitake; Homma, Hirofumi

    2013-02-01

    We measured fluctuations of single DNA molecules stretched by dual trap optical tweezers, and obtained its elastic properties, the force and its derivative, by calculating auto- and cross-correlation functions of the fluctuations. We investigated suitable range of the spring constant of optical tweezers for the detection of the change in the elastic properties. We found that the prediction of worm-like chain model for the elastic properties agrees with the experimentally obtained values when the spring constant of optical tweezers is 2-5 pN/μm in our setup. Moreover, we introduced a fluorescent dye, YOYO-1, into the flow chamber, and the change of the elastic properties of the single DNA molecule was observed. The results show that we can detect the changes of not only the force but also its derivative for the DNA stretched at a fixed extension.

  9. Simulation study of the elastic mechanical properties of HMX

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, T. D. (Thomas D.)

    2002-01-01

    Results of calculations of the elastic mechanical response of crystalline HMX polymorphs are summarized. The work is based on atomistic molecular dynamics and Monte Carlo simulations. Principal achievements are: (1) prediction of room temperature and pressure elastic tensors for {beta}-, {alpha}- and {delta}-HMX; (2) calculation of room temperature isotherms for each polymorph; (3) extraction of initial bulk modulus and pressure derivative from the isotherm; and (4) 'discovery' of a pressure induced phase transition in {alpha}-HMX (preliminary result). Details of the work, and implications, will be discussed.

  10. Effect of Carbon Doping on the Electronic Structure and Elastic Properties of Boron Suboxide

    Science.gov (United States)

    2015-06-01

    of Boron Suboxide by Amol B Rahane, Jennifer S Dunn, and Vijay Kumar Approved for public release; distribution unlimited...Laboratory Effect of Carbon Doping on the Electronic Structure and Elastic Properties of Boron Suboxide by Amol B Rahane and Vijay Kumar Dr...SUBTITLE Effect of Carbon Doping on the Electronic Structure and Elastic Properties of Boron Suboxide 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  11. Physical Properties of Hanford Transuranic Waste

    Energy Technology Data Exchange (ETDEWEB)

    Berg, John C.

    2010-03-25

    The research described herein was undertaken to provide needed physical property descriptions of the Hanford transuranic tank sludges under conditions that might exist during retrieval, treatment, packaging and transportation for disposal. The work addressed the development of a fundamental understanding of the types of systems represented by these sludge suspensions through correlation of the macroscopic rheological properties with particle interactions occurring at the colloidal scale in the various liquid media. The results of the work have advanced existing understanding of the sedimentation and aggregation properties of complex colloidal suspensions. Bench scale models were investigated with respect to their structural, colloidal and rheological properties that should be useful for the development and optimization of techniques to process the wastes at various DOE sites.

  12. Rheological properties of polymer melts with high elasticity

    Science.gov (United States)

    Feranc, Jozef; Matvejová, Martina; Alexy, Pavol; Pret'o, Jozef; Hronkovič, Ján

    2017-05-01

    In the recent years efforts to complex description of the rheological characteristic increase even in the case of polymeric blends with high part of elastic deformation. However, unlike the most thermoplastic these blends have a certain specific features. Besides the already mentioned the higher part of elastic deformation it is especially higher viscosity, which are shown mainly for the measurement in the range of high shear rates. For this reason, the presented work is focused on the description of measurement methodology for blends with high part of elastic deformation using capillary rheometer. The measurements were carried out on a commercial polymer blend with trade name A517 based on rubbery polymer. Capillary rheometer Gottfert RG 75 was used, with diameter of chamber 15 mm. Measurements were performed using capillaries with different ratio of length/diameter at temperature 100°C. Because of existence elastic part of deformation, it is not possible to achieve a steady state pressure using measurements at constant volumetric flow at high shear rates. Therefore we decided to measure the flow characteristic using isobaric mode.

  13. Elastic and piezoelectric properties, sound velocity and Debye ...

    Indian Academy of Sciences (India)

    bismuth compound. ... related to the lowest Gibbs energy, which is given as [14] ... Elastic constants Cij and bulk modulus B in (GPa) of (B3) BBi at zero pressure in comparison with the available theoretical data [2,3,16–22]. C11. C12. C14. B.

  14. Evaluation of the elastic properties of monovalent oxides using ...

    Indian Academy of Sciences (India)

    The ultrasonic velocities (longitudinal and shear) were measured in these glasses using the pulse-echo technique at room temperature. Their elastic moduli, microhardness and Debye temperature were calculated and discussed in terms of the modifier's ionicity and quantitatively in terms of number of bonds per unit volume ...

  15. Elastic and piezoelectric properties, sound velocity and Debye ...

    Indian Academy of Sciences (India)

    Pseudopotential plane-wave method (PP–PW) based on density functional theory (DFT) and density functional perturbation theory (DFPT) within the Teter and Pade exchangecorrelation functional form of the local spin density approximation (LSDA) is applied to study the effect of pressure on the elastic and piezoelectric ...

  16. AELAS: Automatic ELAStic property derivations via high-throughput first-principles computation

    Science.gov (United States)

    Zhang, S. H.; Zhang, R. F.

    2017-11-01

    The elastic properties are fundamental and important for crystalline materials as they relate to other mechanical properties, various thermodynamic qualities as well as some critical physical properties. However, a complete set of experimentally determined elastic properties is only available for a small subset of known materials, and an automatic scheme for the derivations of elastic properties that is adapted to high-throughput computation is much demanding. In this paper, we present the AELAS code, an automated program for calculating second-order elastic constants of both two-dimensional and three-dimensional single crystal materials with any symmetry, which is designed mainly for high-throughput first-principles computation. Other derivations of general elastic properties such as Young's, bulk and shear moduli as well as Poisson's ratio of polycrystal materials, Pugh ratio, Cauchy pressure, elastic anisotropy and elastic stability criterion, are also implemented in this code. The implementation of the code has been critically validated by a lot of evaluations and tests on a broad class of materials including two-dimensional and three-dimensional materials, providing its efficiency and capability for high-throughput screening of specific materials with targeted mechanical properties. Program Files doi:http://dx.doi.org/10.17632/f8fwg4j9tw.1 Licensing provisions: BSD 3-Clause Programming language: Fortran Nature of problem: To automate the calculations of second-order elastic constants and the derivations of other elastic properties for two-dimensional and three-dimensional materials with any symmetry via high-throughput first-principles computation. Solution method: The space-group number is firstly determined by the SPGLIB code [1] and the structure is then redefined to unit cell with IEEE-format [2]. Secondly, based on the determined space group number, a set of distortion modes is automatically specified and the distorted structure files are generated

  17. On the elastic properties of carbon nanotube-based composites: modelling and characterization

    CERN Document Server

    Thostenson, E T

    2003-01-01

    The exceptional mechanical and physical properties observed for carbon nanotubes has stimulated the development of nanotube-based composite materials, but critical challenges exist before we can exploit these extraordinary nanoscale properties in a macroscopic composite. At the nanoscale, the structure of the carbon nanotube strongly influences the overall properties of the composite. The focus of this research is to develop a fundamental understanding of the structure/size influence of carbon nanotubes on the elastic properties of nanotube-based composites. Towards this end, the nanoscale structure and elastic properties of a model composite system of aligned multi-walled carbon nanotubes embedded in a polystyrene matrix were characterized, and a micromechanical approach for modelling of short fibre composites was modified to account for the structure of the nanotube reinforcement to predict the elastic modulus of the nanocomposite as a function of the constituent properties, reinforcement geometry and nanot...

  18. Elastic properties of single-walled carbon nanotube thin film by nanoindentation test.

    Science.gov (United States)

    Tang, Xingling; El-Hami, Abdelkhalak; El-Hami, Khalil; Eid, Mohamed; Si, Chaorun

    2017-09-12

    This paper carries out a preliminary study for the elastic properties of single walled carbon nanotube (SWCNT) thin film. The SWCNT thin films (~250 nm) are prepared by a simple and cost effective method of spin-coating technology. Nanoindentation test with a Berkovich indenter is used to determine the hardness and elastic modulus of the SWCNT thin film. It is important to note that the elastic properties of SWCNT film are indirectly derived from the information of load and displacement of the indenter under certain assumptions, deviation of the 'test value' is inevitable. In this regard, uncertainty analysis is an effective process in guarantying the validity of the material properties. This paper carries out uncertainty estimation for the tested elastic properties of SWCNT film by nanoindentation. Experimental results and uncertainty analysis indicates that nanoindentation test could be an effective and reliable method in determine the elastic properties of SWCNT thin film. Moreover, the obtained values of hardness and elastic modulus can further benefit the design of SWCNT thin film based components.

  19. Elastic and dynamic properties of membrane phase-field models.

    Science.gov (United States)

    Lázaro, Guillermo R; Pagonabarraga, Ignacio; Hernández-Machado, Aurora

    2017-09-01

    Phase-field models have been extensively used to study interfacial phenomena, from solidification to vesicle dynamics. In this article, we analyze a phase-field model that captures the relevant physical features that characterize biological membranes. We show that the Helfrich theory of elasticity of membranes can be applied to phase-field models, allowing to derive the expressions of the stress tensor, lateral stress profile and elastic moduli. We discuss the relevance and interpretations of these magnitudes from a phase-field perspective. Taking the sharp-interface limit we show that the membrane macroscopic equilibrium equation can be derived from the equilibrium condition of the phase-field interface. We also study two dynamic models that describe the behaviour of a membrane. From the study of the relaxational behaviour of the membrane we characterize the relevant dynamics of each model, and discuss their applications.

  20. Structural, elastic and thermodynamic properties of Ti2SC

    Indian Academy of Sciences (India)

    Administrator

    Furthermore, at 316 ± 2 GPa, its Young's modulus is the highest one among M2AX .... Young's modulus E (GPa), Poisson's ratio σ, thermal expansion α (10–5 K–1), Grüneisen parameter γ and elastic constants Cij (GPa) of Ti2SC compared with ..... where E(V) is the total energy per unit cell, PV corre- sponds to the constant ...

  1. Distribution of mesoscale elastic properties and mass density in the human femoral shaft.

    Science.gov (United States)

    Rohrbach, Daniel; Grimal, Quentin; Varga, Peter; Peyrin, Francoise; Langer, Max; Laugier, Pascal; Raum, Kay

    2015-04-01

    Cortical bone properties are determined by tissue composition and structure at several hierarchical length scales. In this study, the spatial distribution of micro- and mesoscale elastic properties within a human femoral shaft has been investigated. Microscale tissue degree of mineralization (DMB), cortical vascular porosity Ct.Po and the average transverse isotropic stiffness tensor C(Micro) of cylindrical-shaped samples (diameter: 4.4 mm, N = 56) were obtained from cortical regions between 20 and 85% of the total femur length and around the periphery (anterior, medial, posterior and lateral quadrants) by means of synchrotron radiation µCT (SRµCT) and 50-MHz scanning acoustic microscopy (SAM). Within each cylinder, the volumetric bone mineral density (vBMD) and the mesoscale stiffness tensor C(Meso) were derived using a numerical homogenization approach. Moreover, microelastic maps of the axial elastic coefficient c33 measured by SAM at distinct cross-sectional locations along the femur were used to construct a 3-D multiscale elastic model of the femoral shaft. Variations of vBMD (6.1%) were much lower than the variations of mesoscale elastic coefficients (11.1-21.3%). The variation of DMB was only a minor predictor for variations of the mesoscale elastic properties (0.05 ≤ R(2) ≤ 0.34). Instead, variations of the mesoscale elastic properties could be explained by variations of cortical porosity and microscale elastic properties. These data were suitable inputs for numerical evaluations and may help to unravel the relations between structure and composition on the elastic function in cortical bone.

  2. On the identification of the eggshell elastic properties under quasistatic compression

    Directory of Open Access Journals (Sweden)

    Jana Simeonovová

    2004-01-01

    Full Text Available The problem of the identification of the elastic properties of eggshell, i.e. the evaluation of the Young's modulus and Poisson's ratio is solved. The eggshell is considered as a rotational shell. The experiments on the egg compression under quasistatic loading have been conducted. During these experiments a strain on the eggshell surface has been recorded. By the mutual comparison between experimental and theoretical values of strains the influence of the elastic constants has been demonstrated.

  3. Influence of limestone waste as partial replacement material for sand and marble powder in concrete properties

    Directory of Open Access Journals (Sweden)

    Omar M. Omar

    2012-12-01

    Full Text Available Green concrete are generally composed of recycling materials as hundred or partial percent substitutes for aggregate, cement, and admixture in concrete. Limestone waste is obtained as a by-product during the production of aggregates through the crushing process of rocks in rubble crusher units. Using quarry waste as a substitute of sand in construction materials would resolve the environmental problems caused by the large-scale depletion of the natural sources of river and mining sands. This paper reports the experimental study undertaken to investigate the influence of partial replacement of sand with limestone waste (LSW, with marble powder (M.P as an additive on the concrete properties. The replacement proportion of sand with limestone waste, 25%, 50%, and 75% were practiced in the concrete mixes except in the concrete mix. Besides, proportions of 5%, 10% and 15% marble powder were practiced in the concrete mixes. The effects of limestone waste as fine aggregate on several fresh and hardened properties of the concretes were investigated. The investigation included testing of compressive strength, indirect tensile strength, flexural strength, modulus of elasticity, and permeability. It was found that limestone waste as fine aggregate enhanced the slump test of the fresh concretes. But the unit weight concretes were not affected. However, the good performance was observed when limestone waste as fine aggregate was used in presence of marble powder.

  4. Nanoindentation study of electrodeposited Ag thin coating: An inverse calculation of anisotropic elastic-plastic properties

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Guang; Sun, Xin; Wang, Yuxin; Tay, See Leng; Gao, Wei

    2017-01-01

    A new inverse method was proposed to calculate the anisotropic elastic-plastic properties (flow stress) of thin electrodeposited Ag coating utilizing nanoindentation tests, previously reported inverse method for isotropic materials and three-dimensional (3-D) finite element analyses (FEA). Indentation depth was ~4% of coating thickness (~10 μm) to avoid substrate effect and different indentation responses were observed in the longitudinal (L) and the transverse (T) directions. The estimated elastic-plastic properties were obtained in the newly developed inverse method by matching the predicted indentation responses in the L and T directions with experimental measurements considering indentation size effect (ISE). The results were validated with tensile flow curves measured from free-standing (FS) Ag film. The current method can be utilized to characterize the anisotropic elastic-plastic properties of coatings and to provide the constitutive properties for coating performance evaluations.

  5. Characterization of nuclear graphite elastic properties using laser ultrasonic methods

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Fan W [Johns Hopkins University; Han, Karen [Johns Hopkins University; Olasov, Lauren R [Johns Hopkins University; Gallego, Nidia C [ORNL; Contescu, Cristian I [ORNL; Spicer, James B [Johns Hopkins University

    2015-01-01

    Laser ultrasonic methods have been used to characterize the elastic behaviors of commercially-available and legacy nuclear graphites. Since ultrasonic techniques are sensitive to various aspects of graphite microstructure including preferred grain orientation, microcrack orientation and porosity, laser ultrasonics is a candidate technique for monitoring graphite degradation and structural integrity in environments expected in high-temperature, gas-cooled nuclear reactors. Aspects of materials texture can be assessed by studying ultrasonic wavespeeds as a function of propagation direction and polarization. Shear wave birefringence measurements, in particular, can be used to evaluate elastic anisotropy. In this work, laser ultrasonic measurements of graphite moduli have been made to provide insight into the relationship between the microstructures and the macroscopic stiffnesses of these materials. In particular, laser ultrasonic measurements have been made using laser line sources to produce shear waves with specific polarizations. By varying the line orientation relative to the sample, shear wave birefringence measurements have been recorded. Results from shear wave birefringence measurements show that an isostatically molded graphite, such as PCIB, behaves isotropically, while an extruded graphite, such as H-451, displays significant ultrasonic texture. Graphites have complicated microstructures that depend on the manufacturing processes used, and ultrasonic texture in these materials could originate from grain orientation and preferred microcrack alignment. Effects on material isotropy due to service related microstructural changes are possible and the ultimate aim of this work is to determine the degree to which these changes can be assessed nondestructively using laser ultrasonics measurements

  6. Elastic properties of the filled and unfilled skutterudite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Y [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Fujino, T [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Kikuchi, F [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Tanizawa, T [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Sun, P [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Nakamura, M [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Yoshino, G [Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Ochiai, A [Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan); Sugawara, H [Faculty of Integrated Arts and Sciences, University of Tokushima, Tokushima, 770-8502 (Japan); Kikuchi, D [Department of Physics, Tokyo Metropolitan University, Hachioji, 192-0397 (Japan); Sato, H [Department of Physics, Tokyo Metropolitan University, Hachioji, 192-0397 (Japan); Yoshizawa, M [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan)

    2007-12-15

    Ultrasonic measurements were made on a single crystal of the unfilled skutterudite compounds RhSb{sub 3} and IrSb{sub 3} and compare with that of the filled skutterudite PrOs{sub 4} Sb{sub 12} to elucidate the role of the guest ions Pr. A characteristic increase was observed around 30 K in the temperature dependence of elastic constants (C{sub 11}-C{sub 12})/2 and C{sub 44} which is ascribed to unusual vibration 'rattling' of Pr ions in an atomic cage formed by Sb-'icosahedron. On the other hand, the elastic constants C{sub 11} (C{sub 11}-C{sub 12})/2 and C{sub 44} increase monotonically with decreasing temperature in the case of RhSb{sub 3} and IrSb{sub 3}. No such a characteristic increase was observed. These results give us a piece of evidence that the guest ions would play a crucial role for 'rattling motion' in filled skutterudite compounds.

  7. Visco-Elastic Properties of Sodium Hyaluronate Solutions

    Science.gov (United States)

    Kulicke, Werner-Michael; Meyer, Fabian; Bingöl, Ali Ö.; Lohmann, Derek

    2008-07-01

    Sodium Hyaluronate (NaHA) is a member of the glycosaminoglycans and is present in the human organism as part of the synovial fluid and the vitreous body. HA is mainly commercialized as sodium or potassium salt. It can be extracted from cockscombs or can be produced by bacterial fermentation ensuring a low protein content. Because of its natural origin and toxicological harmlessness, NaHA is used to a great extent for pharmaceutical and cosmetic products. In medical applications, NaHA is already being used as a component of flushing and stabilizing fluids in the treatment of eye cataract and as a surrogate for natural synovial fluid. Another growing domain in the commercial utilization of NaHA is the field of skin care products like dermal fillers or moisturizers. In this spectrum, NaHA is used in dilute over semidilute up to concentrated (0elastic material functions of different NaHA samples. This includes, besides shear flow and oscillatory experiments, the performance of rheo-optical measurements in order to determine the elastic component in the range of low shear rates and low concentrations.

  8. Determining the elastic properties of aptamer-ricin single molecule multiple pathways

    Science.gov (United States)

    Ricin and an anti-ricin aptamer showed three stable binding conformations with their special chemomechanical properties. The elastic properties of the ricin-aptamer single-molecule interactions were investigated by the dynamic force spectroscopy (DFS). The worm-like-chain model and Hook’s law were ...

  9. Soil physicochemical properties after 10 years of animal waste applications

    Science.gov (United States)

    Application of animal waste to cropland provides a method of waste disposal and benefits both soil and crops. The objective of this study was to evaluate the long-term effects of land application of animal waste and inorganic fertilizer on selected soil chemical and physical properties. The animal w...

  10. Mechanical Properties of Epoxy Resin Mortar with Sand Washing Waste as Filler.

    Science.gov (United States)

    Yemam, Dinberu Molla; Kim, Baek-Joong; Moon, Ji-Yeon; Yi, Chongku

    2017-02-28

    The objective of this study was to investigate the potential use of sand washing waste as filler for epoxy resin mortar. The mechanical properties of four series of mortars containing epoxy binder at 10, 15, 20, and 25 wt. % mixed with sand blended with sand washing waste filler in the range of 0-20 wt. % were examined. The compressive and flexural strength increased with the increase in epoxy and filler content; however, above epoxy 20 wt. %, slight change was seen in strength due to increase in epoxy and filler content. Modulus of elasticity also linearly increased with the increase in filler content, but the use of epoxy content beyond 20 wt. % decreased the modulus of elasticity of the mortar. For epoxy content at 10 wt. %, poor bond strength lower than 0.8 MPa was observed, and adding filler at 20 wt. % adversely affected the bond strength, in contrast to the mortars containing epoxy at 15, 20, 25 wt. %. The results indicate that the sand washing waste can be used as potential filler for epoxy resin mortar to obtain better mechanical properties by adding the optimum level of sand washing waste filler.

  11. Patient-specific modeling of corneal refractive surgery outcomes and inverse estimation of elastic property changes.

    Science.gov (United States)

    Roy, Abhijit Sinha; Dupps, William J

    2011-01-01

    The purpose of this study is to develop a 3D patient-specific finite element model (FEM) of the cornea and sclera to compare predicted and in vivo refractive outcomes and to estimate the corneal elastic property changes associated with each procedure. Both eyes of a patient who underwent laser-assisted in situ keratomileusis (LASIK) for myopic astigmatism were modeled. Pre- and postoperative Scheimpflug anterior and posterior corneal elevation maps were imported into a 3D corneo-scleral FEM with an unrestrained limbus. Preoperative corneal hyperelastic properties were chosen to account for meridional anisotropy. Inverse FEM was used to determine the undeformed corneal state that produced aberration were compared at clinical intraocular pressure. The magnitude of elastic weakening of the residual corneal bed required to maximize the agreement with clinical axial power was calculated and compared with the changes in ocular response analyzer (ORA) measurements. The models produced curvature maps and spherical aberrations equivalent to in vivo measurements. For the preoperative property values used in this study, predicted elastic weakening with LASIK was as high as 55% for a radially uniform model of residual corneal weakening and 65% at the point of maximum ablation in a spatially varying model of weakening. Reductions in ORA variables were also observed. A patient-specific FEM of corneal refractive surgery is presented, which allows the estimation of surgically induced changes in corneal elastic properties. Significant elastic weakening after LASIK was required to replicate clinical topographic outcomes in this two-eye pilot study.

  12. High-pressure structure and elastic properties of tantalum single crystal: First principles investigation

    Science.gov (United States)

    Gu, Jian-Bing; Wang, Chen-Ju; Zhang, Wang-Xi; Sun, Bin; Liu, Guo-Qun; Liu, Dan-Dan; Yang, Xiang-Dong

    2016-12-01

    Since knowledge of the structure and elastic properties of Ta at high pressures is critical for addressing the recent controversies regarding the high-pressure stable phase and elastic properties, we perform a systematical study on the high-pressure structure and elastic properties of the cubic Ta by using the first-principles method. Results show that the initial body-centered cubic phase of Ta remains stable even up to 500 GPa and the high-pressure elastic properties are excellently consistent with the available experimental results. Besides, the high-pressure sound velocities of the single- and poly-crystals Ta are also calculated based on the elastic constants, and the predications exhibit good agreement with the existing experimental data. Project supported by the Basic and Frontier Technical Research Project of Henan Province, China (Grant No. 152300410228), the University Innovation Team Project in Henan Province, China (Grant No. 15IRTSTHN004), and the Key Scientific Research Project of Higher Education of Henan Province, China (Grant No. 17A140014).

  13. Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments

    Energy Technology Data Exchange (ETDEWEB)

    Nihei, K.T.; Nakagawa, S.; Reverdy, F.; Meyer, L.R.; Duranti, L.; Ball, G.

    2010-12-15

    Sediments undergoing compaction typically exhibit transversely isotropic (TI) elastic properties. We present a new experimental apparatus, the phased array compaction cell, for measuring the TI elastic properties of clay-rich sediments during compaction. This apparatus uses matched sets of P- and S-wave ultrasonic transducers located along the sides of the sample and an ultrasonic P-wave phased array source, together with a miniature P-wave receiver on the top and bottom ends of the sample. The phased array measurements are used to form plane P-waves that provide estimates of the phase velocities over a range of angles. From these measurements, the five TI elastic constants can be recovered as the sediment is compacted, without the need for sample unloading, recoring, or reorienting. This paper provides descriptions of the apparatus, the data processing, and an application demonstrating recovery of the evolving TI properties of a compacting marine sediment sample.

  14. Influence of elasticity on the syneresis properties of κ-carrageenan gels.

    Science.gov (United States)

    Ako, Komla

    2015-01-22

    Kappa-carrageenan hydrogels spontaneously release fluid (syneresis) under certain elasticity conditions, which depend on the temperature, the salt concentration in the gel (KCl) and the polysaccharide concentration. Strong and weak gels exhibit notably weak syneresis properties. The maximum syneresis was found at intermediate elasticity where the gel was neither strong nor weak. The variation in the gel composition indicated that the fluid is released according to the thermal retraction coefficient, which depends on the elasticity. Experiments revealed a dynamic equilibrium of the syneresis process where syneresis fluid was not withdrawn. However, once the fluid was removed from the gel surface, the release of solvent starts again if the elasticity is below the compressive pressure in the gel. Therefore, swelling of the gel is suggested as an explanation for the dynamic equilibrium of the syneresis process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. The elastic properties of Mn3(Cu1−xGexN compounds

    Directory of Open Access Journals (Sweden)

    B. Y. Qu

    2011-12-01

    Full Text Available We present an ab initio study of the elastic properties of the negative thermal expansion (NTE compound Mn3(Cu1−xGexN. The calculated energies show that the Ge atoms can be easily doped into the compound and, the distribution of the Ge atoms in the compound is very uniform. The elastic moduli of the compound in the form of polycrystalline are evaluated according to the Voigt-Reuss-Hill approximation, which show that the doped Ge enhances the ductile character of the compound, with fairly high elastic anisotropy. Furthermore, it is found that the bulk modulus and the Young's modulus of the compound increase as the Ge content increases from 12.5 % to 50 %, being in agreement with experiments. Through analyzing the electronic structures, we propose that these elastic features are essentially stemmed from the valence states and the valence electrons of the doped Ge.

  16. Influence of point defects on the elastic properties of mantle minerals and superhard materials

    Science.gov (United States)

    Chang, Yun-Yuan

    Perfect crystals do not exist in nature. Defects in crystals modify their physical and chemical properties. Elastic properties relate stress to reversible strain and reflect the strength of interatomic bonding forces, which may be influenced by defects. This thesis advances our understanding of how defects influence the elastic properties of mantle minerals and superhard materials. In this study, I focused on defects associated with ferric iron (Fe 3+) and hydrogen (H) substitution in mantle minerals with application to interpreting the water content of the mantle from observed seismic wave speeds. High-pressure, single-crystal X-ray diffraction experiments were carried out to determine the comparative compressibility of hydrous and anhydrous Fo90 wadsleyite, the dominant phase in Earth's mantle transition zone (410-660 km depth). The results show that hydration of wadsleyite with 1 wt.% H2O reduces its bulk modulus by 4.7%, but has no influence on its pressure derivative. Therefore, the reduction in bulk sound velocity of wadsleyite associated with H defects should persist to mantle pressures. In another study, the equation of state and electronic spin state of ferric iron (Fe3+) in Fe-Al-phase D were determined, pertaining to dense hydrous magnesium silicates that could potentially transport water into the lower mantle. The results show that Fe3+ undergoes a gradual spin transition between 40 and 65 GPa, causing pronounced bulk-elastic softening of Fe-Al phase D within the spin transition pressure interval. Results provide an alternative interpretation for small-scale seismic heterogeneities beneath the Pacific rim. In addition to mantle silicates, I have determined the influence of nitrogen defects on the elastic properties of natural and synthetic diamond. The measurements of elastic moduli of synthetic nano-polycrystalline diamond (NPD) and natural type Ia diamond feature a newly developed optical contact micrometer for ultrasonic sample thickness measurements

  17. Mechanical properties of concrete with SAP. Part II: Modulus of elasticity

    DEFF Research Database (Denmark)

    Hasholt, Marianne Tange; Jespersen, Morten H. Seneka; Jensen, Ole Mejlhede

    2010-01-01

    of air voids. Second, SAP addition may at the same time lead to increased compressive strength (as shown in [5]) and reduced E-modulus. A prediction based solely on compressive strength therefore overrates the modulus of elasticity, so the empirical models are unsafe to use for concrete with SAP......, and air with volume fractions of the three phases as well as elastic properties of paste and aggregates as input parameters. Addition of SAP changes the E-modulus, because it both has an influence on properties of the cement paste and on the volume of air voids. Here, the E-modulus is an example...... of a mechanical property, and the same methodology can probably be applied to other mechanical properties. It is often assumed that a range of mechanical properties of concrete can be derived if the compressive strength is known. The link between the compressive strength and other mechanical properties is often...

  18. Large Scale FEM of the effective elastic properties of particle reinforced composites

    DEFF Research Database (Denmark)

    Rauhe, Jens Christian; Pyrz, Ryszard; Lund, Erik

    2004-01-01

    Over the years several methods have been proposed for the determination of the effective elastic properties of particle reinforced composites. The material microstructures used in the present analysis is a real microstructure and a numerically generated microstructure. X-ray microtomography is used...... three-dimensional finite element models of the microstructure. The models contain a large number of elements, up to 1 million, and are solved iteratively using an element-by-element formalism. Models containing 100 particles have been statistically generated and the material properties of each particle...... is assigned using a Gaussian distribution of the properties. Various distributions have been used to determine how the variation of particle properties influences the effective elastic properties. From this examination it was found that the larger the variation of the particle properties is the softer...

  19. Determination of effective elastic properties of metal matrix composites with damage particulates using homogenization method

    Science.gov (United States)

    Halim, S. Z.; Basaruddin, K. S.; Ibrahim, I.; Majid, M. S. Abdul; Ridzuan, M. J. M.

    2017-10-01

    The present study aims to investigate the effect of micro-damage in particulates metal matrix composite on the elastic properties. The micro damage that perhaps could occurs during manufacturing process or due to environmental effects was modelled in three different types, namely shattered, debonded and breakage particulates with variation of volume fraction. The modelling and analysis were conducted based on homogenization theory by utilizing multiscale finite element software (Voxelxon). The results suggest that the elastic properties of metal matrix composite was sensitive to the geometrical defects of its particle.

  20. Effects of Kyunghee Facial Resistance Program (KFRP) on mechanical and elastic properties of skin.

    Science.gov (United States)

    Kim, Kyunghee; Jeon, Serim; Kim, Jong-Kyung; Hwang, Jae Sung

    2016-01-01

    Facial skin aging is influenced by weakened mimetic muscles. Resistance training of facial mimetic muscles could be one of practical strategy to defend against age-related changes. The aim of this study was to investigate the effects of an exercise program (KFRP: Kyunghee Facial Resistance Program) designed for facial mimetic muscles on the mechanical properties and elasticity of facial skin. For this study, 16 healthy female volunteers aged 35-58 participated in KFRP for eight weeks. The mechanical and elastic properties of skin were measured using a Cutometer® on the face and neck. The parameters representing skin fatigue decreased and the parameters representing skin elasticity increased significantly compared to the baseline in all measured regions. The ability of re-deformation of skin increased significantly except the zygomaticus and platysma muscle regions. All measured regions of skin became firmer and the ability to return to the initial position was also significantly improved compared to the baseline. Visco-elasticiy of the skin was not significantly altered. The skin became more firm and elastic through KFRP. This method of resistive exercise had a significantly positive influence on the mechanical properties and elasticity of facial and neck skin.

  1. Integrated petrophysics and rock physics modeling for well log interpretation of elastic, electrical, and petrophysical properties

    Science.gov (United States)

    Wu, Wenting; Grana, Dario

    2017-11-01

    Rock and fluid volumetric properties, such as porosity, saturation, and mineral volumes, are generally estimated from petrophysical measurements such as density, resistivity, neutron porosity and gamma ray, through petrophysical equations. The computed petrophysical properties and sonic log measurements are generally used to estimate the petro-elastic relationship between elastic and rock and fluid volumetric properties used in reservoir characterization. In this paper, we present a unified workflow that includes petrophysical relations and rock physics models for the estimation of rock and fluid properties from elastic, electrical, and petrophysical (porosity, density, and lithology) measurements. The multi-physics model we propose has the advantage of accounting for the coupled effect of rock and fluid properties in the joint petro-elastic and electrical domains, and potentially reduce the uncertainty in the well log interpretation. Furthermore, the presented workflow can be eventually extended to three-dimensional reservoir characterization problems, where seismic and electromagnetic data are available. To demonstrate the validity of the methodology, we show the application of this multi-physics model to both laboratory measurements and well log data.

  2. Moisture Comfort and Antibacterial Properties of Elastic Warp-Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Yu Zhi-Cai

    2015-03-01

    Full Text Available Multifunction elastic warp-knitted fabrics were fabricated on a crochet machine with the use of metal composite yarns/viscose yarn and bamboo polyester/ crisscross-section polyester hybrid yarns as the front face and back face of the knitted fabric structure, respectively. We investigated the effect of the blend ratio of bamboo charcoal/ crisscross-section polyester multiply yarns on the fabric's moisture comfort properties, such as water vapour transmission (WVT, water evaporation rate (WER, and water absorbency. The results showed that blending ratio significantly influenced WVT and WER. Moreover, antibacterial activity of the elastic warp- knitted fabric was tested against Staphylococcus aureus and Escherichia coli in accordance with AATCC 90-2011. Finally, the extension- stress value curves were used to analyse the elastic stretching property, and the fabric exhibited greater breaking elongation and lower stress value in the walewise than in the weft direction.

  3. Determination of the Elastic Properties of Tomato Fruit Cells with an Atomic Force Microscope

    Directory of Open Access Journals (Sweden)

    Andrzej Kurenda

    2013-09-01

    Full Text Available Since the mechanical properties of single cells together with the intercellular adhesive properties determine the macro-mechanical properties of plants, a method for evaluation of the cell elastic properties is needed to help explanation of the behavior of fruits and vegetables in handling and food processing. For this purpose, indentation of tomato mesocarp cells with an atomic force microscope was used. The Young’s modulus of a cell using the Hertz and Sneddon models, and stiffness were calculated from force-indentation curves. Use of two probes of distinct radius of curvature (20 nm and 10,000 nm showed that the measured elastic properties were significantly affected by tip geometry. The Young’s modulus was about 100 kPa ± 35 kPa and 20 kPa ± 14 kPa for the sharper tip and a bead tip, respectively. Moreover, large variability regarding elastic properties (>100% among cells sampled from the same region in the fruit was observed. We showed that AFM provides the possibility of combining nano-mechanical properties with topography imaging, which could be very useful for the study of structure-related properties of fruits and vegetables at the cellular and sub-cellular scale.

  4. Modeling of elastic-strength properties of elastomers

    Directory of Open Access Journals (Sweden)

    O. V. Karmanova

    2016-01-01

    Full Text Available Model "structure-property", which takes into account the structural heterogeneity of polymer compositions has been developed. Experimental compositions based on styrene-butadiene rubber SCS 30ARK and crosslinked, high viscosity polymer (high-molecular filler - VMN in different proportions, as well as softeners (industrial oil I-12A, oil PN-6, low-molecular polybutadiene PBN were investigated. Samples that differ significantly in viscosity were obtained. The rubber blends and vulcanizates, based on the experimental of polymer compositions, were prepared. Physico-mechanical properties - tensile strength, elongation at break, Shore A. A hardness were determined. For describe the physical and mechanical properties of polymers logarithmic additivity rule was used. The properties of the polymer composition (PС were determined by a single dominant component (resin composition consisting of a high rubber and a filler and further components (softeners. Identification algorithm consists of four steps. The implementation of this algorithm is carried out using experimental design techniques. Estimation of the unknown parameters in the equation was carried out using the method of least squares. Quality evaluation of the model was conducted with the criteria Fisher, turning points, the Durbin-Watson, R / S-criterion. It is found that the model adequately describes the change of physicomechanical properties depending on the composition of polymer compositions. 3d graphics of the physical-mechanical properties of the polymer compositions were built. This allowed us to estimate the contribution of the dominant component and optional components (including combinations thereof to change the parameters. It has been established that the introduction of rubber in total more than 50% of the components (BMH and softeners reduced conventional tensile strength and dramatically increases the relative error of model calculations. (BMH and softeners

  5. EVALUATION OF ELASTICITY AND MECHANICAL PROPERTIES OF BREAD DOUGH MADE WITH REPLACED FLOUR POTATO (IPOMOEA BATATA

    Directory of Open Access Journals (Sweden)

    Ely Fernando Sacón Vera

    2016-10-01

    Full Text Available The effect of the incorporation of sweet potato flour, with 30% replacement in 1kg of wheat flour was evaluated to determine the behavior of elastic and mechanical properties during the kneading and baking stage of bread. For the evaluation the following varieties were studied: Morado Brazil, Morado Ecuador, Guayaco Morado, Ina and Toquecita, and the evaluated properties were: texture (hardness, elasticity, firmness, chewiness measured by a texture meter Bloomfield and volume was measured by INEN standard (NTE INEN 0530: 80. The design employed was completely at random, using analysis of variance at 5% significance level. The results obtained showed that elasticity attribute in texture variable presented significant differences (P <0.05. Analysis concluded that including Toquecita flour in the mixture to form the dough, had the highest elasticity of 13.32mm. However, Morado Ecuador variety flour presented a 6.24 mm elasticity value, ideal for both the malleability of the dough and the freshness of the bread, and concerning volume, the inclusion of Ecuador Morado flour and Ina in the formulation of bread, showed an increase in volume at 93.30 and 93.67cm3 respectively, close to the normed value for wheat flour bread.

  6. Elastic modulus and viscoelastic properties of full thickness skin characterised at micro scales.

    Science.gov (United States)

    Crichton, Michael L; Chen, Xianfeng; Huang, Han; Kendall, Mark A F

    2013-03-01

    The recent emergence of micro-devices for vaccine delivery into upper layers of the skin holds potential for increased immune responses using physical means to target abundant immune cell populations. A challenge in doing this has been a limited understanding of the skin elastic properties at the micro scale (i.e. on the order of a cell diameter; ~10 μm). Here, we quantify skin's elastic properties at a micro-scale by fabricating customised probes of scales from sub- to super-cellular (0.5 μm-20 μm radius). We then probe full thickness skin; first with force-relaxation experiments and subsequently by elastic indentations. We find that skin's viscoelastic response is scale-independent: consistently a ~40% decrease in normalised force over the first second, followed by further 10% reduction over 10 s. Using Prony series and Hertzian contact analyses, we determined the strain-rate independent elastic moduli of the skin. A high scale dependency was found: the smallest probe encountered the highest elastic modulus (~30 MPa), whereas the 20 μm radius probe was lowest (below 1 MPa). We propose that this may be a result of the load distribution in skin facilitated by the hard corneocytes in the outermost skin layers, and softer living cell layers below. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Structural and elastic properties of Ge after Kr-ion irradiation at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Birtcher, R.C.; Grimsditch, M.H. (Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)); McNeil, L.E. (Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599-3255 (United States))

    1994-10-01

    Changes in the elastic properties of Ge induced by room-temperature irradiation with 3.5-MeV Kr ions have been determined and correlated with changes in the microstructure determined by transmission electron microscopy. Elastic-shear-moduli changes were measured by Brillouin scattering, and changes in local atomic arrangement were determined by Raman scattering. Amorphization decreased the elastic shear modulus of Ge by 17%. The fractional decrease was correlated with the amorphous volume fraction with a cross section of 4.5[plus minus]0.5 nm[sup 2]/ion. No change was observed in the shear modulus during void formation and growth. The elastic properties of the voided material are described by the Voigt averaging. However, as the voids evolved into a fibrous spongelike microstructure, a second dramatic elastic softening occurs which we attribute to the inability of the fibrous structure to support shear stresses. Raman scattering showed that, once formed, there was no change in the structure of the amorphous material at the atomic scale during void formation and subsequent void coalescence.

  8. Coupling liquids acoustic velocity effects on elastic metallic bioglass properties

    Science.gov (United States)

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

    2009-11-01

    The effect of surface acoustic wave, SAW, velocities of coupling liquids on acoustical properties of several bulk metallic glasses, BMG, has been investigated using simulation program based on acoustic microscopy. Thus, we determined variations of critical angles at which the excitation of longitudinal mode, θL and Rayleigh mode, θR occurs as a function of wave velocities in different coupling liquids, Vliq. Linear relations of the form θi =ai0 +βiVliq were deduced. The importance of such formula, used with Snell's law, lies in the direct determination of SAW velocities and consequently mechanical properties of BMGs.

  9. Structural, vibrational, elastic and topological properties of PaN under pressure

    DEFF Research Database (Denmark)

    Modak, P.; K. Verma, Ashok; Svane, A.

    2013-01-01

    Electronic, structural, vibrational and elastic properties of PaN have been studied both at ambient and high pressures, using first principles methods with several commonly used parameterizations of the exchange-correlation energy. The generalized gradient approximation (GGA) reproduces the ground...

  10. Comparison of the mechanical properties of therapeutic elastic tapes used in sports and clinical practice.

    Science.gov (United States)

    Matheus, Joao Paulo Chieregato; Zille, Rafael Ribeiro; Gomide Matheus, Liana Barbaresco; Lemos, Thiago Vilela; Carregaro, Rodrigo Luiz; Shimano, Antônio Carlos

    2017-03-01

    Cross-sectional laboratory study. The aim of the present study was to evaluate and compare the mechanical properties of different therapeutic elastic tapes used in sports and clinical practice. Therapeutic tapes have been used since around the 1800s. They are composed of cotton, elastic filaments and adhesive glue that provides an effect of tactile and mechanical stimulation. However, as taping has evolved, manufacturers have implemented new materials and claim that the tensile properties and adhesion of tapes contribute more significantly in the rehabilitation process. Fifty samples of elastic tapes (5 different manufacturers; 10 samples from each manufacturer) were submitted to longitudinal traction until rupture as well as surface adherence assays. Information was recorded on maximum deformation, maximum load, maximum tension and relative stiffness. In tensile testing the bandages brand Kinesio Tex Gold - FP(®) showed higher rates, 3 in 4 properties. During surface adherence tests on the therapeutic elastic tapes the brand Premium Kinesiology 3 NS Tex(®) showed higher rates, 3 in 4 properties analyzed. Tapes from different manufacturers exhibit different characteristics regarding traction and adherence mechanics. Knowledge of these characteristics is fundamental for the optimized use of each tape based on specific therapeutic needs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Toward Characterization of Single Crystal Elastic Properties in Polycrystalline Materials using Resonant Ultrasound (Preprint)

    Science.gov (United States)

    2017-04-06

    AFRL-RX-WP-JA-2017-0331 TOWARD CHARACTERIZATION OF SINGLE CRYSTAL ELASTIC PROPERTIES IN POLYCRYSTALLINE MATERIALS USING RESONANT...STINFO COPY) AIR FORCE RESEARCH LABORATORY MATERIALS AND MANUFACTURING DIRECTORATE WRIGHT-PATTERSON AIR FORCE BASE, OH 45433-7750 AIR...Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway , Suite 1204, Arlington, VA 22202-4302

  12. Using strong nonlinearity and high-frequency vibrations to control effective properties of discrete elastic waveguides

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Thomsen, Jon Juel; Snaeland, Sveinn Orri

    2008-01-01

    The aim of this article is to investigate how highfrequency (HF) excitation, combined with strong nonlinear elastic material behavior, influences the effective material or structural properties for low-frequency excitation and wave propagation. The HF effects are demonstrated on discrete linear...

  13. Elastic properties of model 3-D porous ceramics and foams

    Science.gov (United States)

    Roberts, Anthony; Garboczi, Edward

    2000-03-01

    The novel properties of many new porous materials are related to their interesting internal microstructure. Apart from simple cases, there exist no theoretical means of predicting the bulk properties of these materials. This limits our ability to guide microstructure optimization for a particular purpose. We use a large scale finite element method to demonstrate the complex relationship between microstructure and the effective properties of realistic three-dimensional model porous ceramics and foams. We find that pore-shape and interconnectivity strongly influence the properties of sintered ceramics. For porous foams we have studied the role of coordination number, random disorder, and strut shape on the Young's modulus and Poisson's ratio. We find that that Voronoi tesselations, commonly used to model solid foams, show unphysical behavior, in particular they are incompressible (rubber-like) at low densities. Deletion of just 10% of the bonds in the model reduces the bulk modulus by 75%, more in line with experimental evidence. The FEM results are generally in good agreement with experimental data for ceramics and foams, and can be used as both a predictive and interpretative tool by experimentalists.

  14. Ultrasonic measurement of the elastic properties of benzoyl glycine ...

    Indian Academy of Sciences (India)

    [16] H J McSkimin, in Physical acoustics edited by W P Mason (Academic Press, New. York, 1964) vol. I. Pt. A. [17] J F Nye, Physical properties of crystals (Oxford University Press, London, 1957). [18] B A Auld, Acoustic fields and waves in solids (John Wiley and Sons, NY, 1973) vol. 1. 94. Pramana - J. Phys., Vol. 62, No.

  15. Elastic and Thermodynamic Properties of Zirconium and Hafnium ...

    Indian Academy of Sciences (India)

    65

    Intermetallic Compound– Potential Aerospace Material. M. Manjula, M. Sundareswari* and E. Viswanathan. Department of Physics, Sathyabama University, Tamilnadu, India. Email: sundare65@gmail.com. Abstract. Structural, electronic, mechanical and thermodynamic properties of Rh3Zrx V1-x and Rh3HfxV1-x.

  16. A Nanoscale Simulation Study of Elastic Properties of Gaspeite

    Directory of Open Access Journals (Sweden)

    Benazzouz Brahim-Khalil

    2015-02-01

    Full Text Available The study of structural and mechanical properties of carbonate rock is an interesting subject in engineering and its different applications. In this paper, the crystal structure of gaspeite (NiCO3 is investigated by carrying out molecular dynamics simulations based on energy minimization technique using an interatomic interaction potential.

  17. Physical and elastic properties of marine sediments off Bombay, India

    Digital Repository Service at National Institute of Oceanography (India)

    SubbaRaju, L.V.; Ramana, Y.V.

    45'N and 21 degrees 00N. Representative core samples preserving their natural state were also retrieved from the region in the water depths ranging from 5 to 70 m for the determination of physical properties in the laboratory. Data on the physical...

  18. A simplified approach to determining "effective" elastic mechanical properties of fiber-polymer composite systems

    Science.gov (United States)

    Daggett, Susan Small

    The main objective of the research described herein was to find a method to improve the estimates of mechanical properties-especially elastic properties-in order to reduce the amount of point design testing needed to characterize laminated fiber composites. The specific approach evaluated was "reverse calculation" of the lamina properties from laminate properties for pairs of laminates. Tensile test data with biaxial strain gages were obtained for six to twelve replications for each of seven different laminate configurations of AS4/APC-2 graphite/PEEK. All laminates except the pure 90-deg laminate had between 0 and 25-percent 90-degree plies. The research showed that, for certain pairs of laminates, lamina elastic properties determined from reverse calculation improve the prediction of laminate elastic properties, compared to traditional approaches for obtaining lamina properties (ASTM D3039 and D3518 methods). This is particularly true for the laminate major Poisson's ratio, nusb{xy}, and for the laminate axial modulus, Esb{xy}, at high strains for ductile laminates, which may be very important in such areas of study as fracture mechanics where strains at the edge of a flaw can be very high. The pairs which provided the best correlation had one highly directional laminate with more than forty percent 0-degree plies, and one ductile laminate with 75-percent ±45-degree plies.

  19. Delineation of First-Order Elastic Property Closures for Hexagonal Metals Using Fast Fourier Transforms

    Directory of Open Access Journals (Sweden)

    Nicholas W. Landry

    2015-09-01

    Full Text Available Property closures are envelopes representing the complete set of theoretically feasible macroscopic property combinations for a given material system. In this paper, we present a computational procedure based on fast Fourier transforms (FFTs to delineation of elastic property closures for hexagonal close packed (HCP metals. The procedure consists of building a database of non-zero Fourier transforms for each component of the elastic stiffness tensor, calculating the Fourier transforms of orientation distribution functions (ODFs, and calculating the ODF-to-elastic property bounds in the Fourier space. In earlier studies, HCP closures were computed using the generalized spherical harmonics (GSH representation and an assumption of orthotropic sample symmetry; here, the FFT approach allowed us to successfully calculate the closures for a range of HCP metals without invoking any sample symmetry assumption. The methodology presented here facilitates for the first time computation of property closures involving normal-shear coupling stiffness coefficients. We found that the representation of these property linkages using FFTs need more terms compared to GSH representations. However, the use of FFT representations reduces the computational time involved in producing the property closures due to the use of fast FFT algorithms. Moreover, FFT algorithms are readily available as opposed to GSH codes.

  20. Estimating of the Elastic Properties of the Composite with Anisotropic Ball Inclusions

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2014-01-01

    Full Text Available Scope composites as structural materials sensing mechanical stresses are largely determined by a complex of their elastic properties. Described in the article of review papers devoted to the elastic properties of the composite, it follows that the problem of theoretical evaluation of these characteristics, remains relevant. When considering composites reinforced with spherical inclusions, most famous works of the composite matrix and the inclusion is considered to be isotropic. However, for use as inclusions of metal particles and nanostructured elements often need to consider the anisotropy of the elastic characteristics.In the article for a composite with anisotropic spherical inclusions built two types of estimates of values of the bulk modulus and shear modulus . As background information used elastic properties of the matrix and the inclusions and their content by volume in the composite.The first type is classified as two-sided estimates of desired values that are based on the dual variational formulation of the linear elasticity problem of an inhomogeneous solid body containing alternative functionals (Lagrange and Castigliano. These functionals on the true distribution of strains and stresses in an inhomogeneous body reach the same meaning extremes (minimum and maximum respectively. On the convergence of the distribution of the Lagrange functional application allows you to get an upper bound of desired values, and the use of functional Castigliano - their lower bound.The second type of assessment is built by self-consistency, this method allows for the interaction of a single particle on or matrix composite with a homogeneous isotropic medium having measured the elastic moduli. Averaging over the volume of the composite disturbances arising strains and stresses in the inclusions and matrix particles makes it possible to obtain the calculated dependences for the bulk modulus and shear modulus of the composite. Comparison of these

  1. Extracting elastic properties of an atomically thin interfacial layer by time-domain analysis of femtosecond acoustics

    Science.gov (United States)

    Chen, H.-Y.; Huang, Y.-R.; Shih, H.-Y.; Chen, M.-J.; Sheu, J.-K.; Sun, C.-K.

    2017-11-01

    Modern devices adopting denser designs and complex 3D structures have created much more interfaces than before, where atomically thin interfacial layers could form. However, fundamental information such as the elastic property of the interfacial layers is hard to measure. The elastic property of the interfacial layer is of great importance in both thermal management and nano-engineering of modern devices. Appropriate techniques to probe the elastic properties of interfacial layers as thin as only several atoms are thus critically needed. In this work, we demonstrated the feasibility of utilizing the time-resolved femtosecond acoustics technique to extract the elastic properties and mass density of a 1.85-nm-thick interfacial layer, with the aid of transmission electron microscopy. We believe that this femtosecond acoustics approach will provide a strategy to measure the absolute elastic properties of atomically thin interfacial layers.

  2. To the theory of elastic properties of isotropic magnetic gels. Effect of interparticle interaction

    Science.gov (United States)

    Lopez-Lopez, M. T.; Iskakova, L. Yu; Zubarev, A. Yu; Borin, D. Yu

    2017-09-01

    The paper deals with theoretical study of elastic shear properties of a magnetic gel, consisting of spherical magnetizable particles, randomly (gas-like) distributed in an elastic matrix. We suppose that the composite is placed in a magnetic field, perpendicular to the direction of the sample shear. In order to get mathematically rigorous results, we have restricted ourselves by the analysis of the system with a low concentration of the particles. Magnetic and elastic (through the matrix deformation) interactions between them are considered in the framework of the regular pair approximation. Analysis shows that external magnetic field decreases the macroscopic shear modulus of the composite with a low concentration of the particles. The decreasing dependence of the modulus on the macroscopic shear is estimated. We believe that the suggested rigorous approach can be a robust background for the study of the systems with a high concentration of the particles.

  3. Elastic property of TbRu{sub 4}P{sub 12} under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Y., E-mail: yoshiki@iwate-u.ac.j [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Ito, K.; Kamiyama, T.; Nakamura, M.; Yoshizawa, M. [Graduate School of Engineering, Iwate University, Morioka 020-8551 (Japan); Ohashi, M. [Department of Physics, Kyushu University, Fukuoka 810-8560 (Japan); Oomi, G.; Kosaka, M. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Sekine, C. [Faculty of Engineering, Muroran Institute of Technology, Muroran 050-8585 (Japan); Shirotani, I. [Department of Physics, Saitama University, Saitama 338-8570 (Japan)

    2009-10-15

    We investigated elastic properties of the filled skutterudite compound with heavy lanthanide TbRu{sub 4}P{sub 12} by means of ultrasonic measurements under pressure for the first time. TbRu{sub 4}P{sub 12} undergoes a two successive phase transition from a paramagnetic to an antiferromagnetically ordered phase at T{sub N}approx20K, then to another phase transition at T{sub 1}approx10K. We found that a clear elastic anomaly was observed at the two successive phase transition. Furthermore, it is found that they both show a significant pressure dependence. A steep decrease closely associated with T{sub N} is suppressed significantly, but it hardly shifts by applying the pressure. On the other hand, a slight anomaly associated with T{sub 1} is gradually suppressed and shifts to lower temperatures by applying the pressure. We argue the elastic behavior and the possible interpretation in each ordering phase.

  4. Simulation based modeling of the elastic properties of structural wood based composite lumber

    Science.gov (United States)

    Bejo, Laszlo

    The importance of wood-based composite lumber is increasing in the US market for construction materials. Manufacturers of such composites strive to make their products more competitive by increasing their value. This dissertation describes the development of simulation models that can aid these efforts by estimating the elastic characteristics of composite lumber products. The study included the assessment of the orthotropic mechanical properties of the raw material, the effect of densification it experiences during the hot-pressing procedure, and the geometric structure of the composites. Using the results of these investigations, computer models were created based on principles of deterministic and stochastic simulations. Generated elastic parameters were validated against experimentally measured MOE values. Reasonably good agreement between the simulated and actual elastic constants confirmed the usefulness of the developed models. The simulations can be used to explore the characteristics of composite beams with innovative designs or containing new raw materials before they enter the prototype phase of their development.

  5. Elastic-plastic properties of graphene engineered by oxygen functional groups

    Science.gov (United States)

    Hou, Yuan; Zhu, YinBo; Liu, XiaoYi; Dai, ZhaoHe; Liu, LuQi; Wu, HengAn; Zhang, Zhong

    2017-09-01

    Using molecular dynamics (MD) simulations, we investigate the elastic-plastic mechanical performances of monolayer graphene oxide (GO) under uniaxial tension. The brittle-ductile-brittle transition and nonlinear-linear-nonlinear elastic transition is found in the uniaxial tension of GO, which displays strong correlations to the content, distribution and proportion of oxygen functional groups. In principle, the tensile behavior of graphene with epoxy groups exhibits ductile fracture features due to the unique epoxy-to-ether transformation in structural evolution. Our simulation results also reveal that wrinkling could cause a competing mechanism of strain-hardening or -softening, and in turn, the nonlinear-linear elasticity transition. Moreover, we propose a continuum mechanical model with a modified stress-strain relation to understand the unique deformation performances, which is consistent with the MD results. These findings might provide valuable insight and design guidelines for optimizing the specific mechanical properties and deformation behaviors of graphene and its derivatives.

  6. Influence of tool elasticity on process forces and joint properties during clinching with rotational tool movement

    Science.gov (United States)

    Hiller, Maria; Benkert, Tim; Vitzthum, Simon; Volk, Wolfram

    2017-09-01

    Clinching as a joining method for sheet metal components offers various advantages. Therefore, the process optimization using finite element simulations is continuously increasing. For translational clinching, the use of rigid tools results in a good prediction of process forces and joint properties. In case of roller clinching, the lateral forces acting on the punch lead to significant elastic tool deformation during the process. This paper focuses on the effects of the tool elasticity on the joining forces, the tool deformation and the joint formation during roller clinching. The results are obtained using the finite element tool Abaqus. To evaluate whether higher simulation costs in form of elastic tools are necessary, the obtained clinchpoints are compared to experimental data.

  7. Absorption properties of waste matrix materials

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, J.B. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1997-06-01

    This paper very briefly discusses the need for studies of the limiting critical concentration of radioactive waste matrix materials. Calculated limiting critical concentration values for some common waste materials are listed. However, for systems containing large quantities of waste materials, differences up to 10% in calculated k{sub eff} values are obtained by changing cross section data sets. Therefore, experimental results are needed to compare with calculation results for resolving these differences and establishing realistic biases.

  8. Stress-dependent elastic properties of shales—laboratory experiments at seismic and ultrasonic frequencies

    Science.gov (United States)

    Szewczyk, Dawid; Bauer, Andreas; Holt, Rune M.

    2018-01-01

    Knowledge about the stress sensitivity of elastic properties and velocities of shales is important for the interpretation of seismic time-lapse data taken as part of reservoir and caprock surveillance of both unconventional and conventional oil and gas fields (e.g. during 4-D monitoring of CO2 storage). Rock physics models are often developed based on laboratory measurements at ultrasonic frequencies. However, as shown previously, shales exhibit large seismic dispersion, and it is possible that stress sensitivities of velocities are also frequency dependent. In this work, we report on a series of seismic and ultrasonic laboratory tests in which the stress sensitivity of elastic properties of Mancos shale and Pierre shale I were investigated. The shales were tested at different water saturations. Dynamic rock engineering parameters and elastic wave velocities were examined on core plugs exposed to isotropic loading. Experiments were carried out in an apparatus allowing for static-compaction and dynamic measurements at seismic and ultrasonic frequencies within single test. For both shale types, we present and discuss experimental results that demonstrate dispersion and stress sensitivity of the rock stiffness, as well as P- and S-wave velocities, and stiffness anisotropy. Our experimental results show that the stress-sensitivity of shales is different at seismic and ultrasonic frequencies, which can be linked with simultaneously occurring changes in the dispersion with applied stress. Measured stress sensitivity of elastic properties for relatively dry samples was higher at seismic frequencies however, the increasing saturation of shales decreases the difference between seismic and ultrasonic stress-sensitivities, and for moist samples stress-sensitivity is higher at ultrasonic frequencies. Simultaneously, the increased saturation highly increases the dispersion in shales. We have also found that the stress-sensitivity is highly anisotropic in both shales and that in

  9. Regional stretch method to measure the elastic and hyperelastic properties of soft materials

    Science.gov (United States)

    Sheng, JunYuan; Guo, HaoYuan; Cao, YanPing; Feng, XiQiao

    2018-02-01

    Characterizing the mechanical properties of soft materials and biological tissues is of great significance for understanding their deformation behaviors. In this paper, a regional stretching method is proposed to measure the elastic and hyperelastic properties of a soft material with an adhesive surface or with the aid of glue. Theoretical and dimensional analyses are performed to investigate the regional stretch problem for soft materials that obey the neo-Hookean model, the Mooney-Rivlin model, or the Arruda-Boyce model. Finite element simulations are made to determine the expressions of the dimensionless functions that correlate the stretch response with the constitutive parameters. Thereby, an inverse approach is established to determine the elastic and hyperelastic properties of the tested materials. The regional stretch method is also compared to the indentation technique. Finally, experiments are performed to demonstrate the effectiveness of the proposed method.

  10. The temperature behaviour of the elastic and thermodynamic properties of fcc thorium

    Energy Technology Data Exchange (ETDEWEB)

    Jaroszewicz, S., E-mail: jaroszew@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin (Argentina); Instituto de Tecnologia Jorge A. Sabato, UNSAM-CNEA (Argentina); Mosca, H.O. [Gerencia de Investigacion y Aplicaciones, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, San Martin (Argentina); Instituto de Tecnologia Jorge A. Sabato, UNSAM-CNEA (Argentina); Garces, J.E. [DAEE, Centro Atomico Bariloche, Comisin Nacional de Energia Atomica, Av. Bustillo 9500, Bariloche, Rio Negro (Argentina)

    2012-10-15

    The temperature behaviour of the structural, elastical and thermal properties of fcc thorium have been calculated from a free-parameter Helmholtz free energy developed by computing the cohesive energy from first principles calculations coupled to the Chen-Moebius lattice inversion method and the Debye-Grueneisen quasiharmonic model. The elastic constants, shear modulus, Young modulus, Poisson's ratio and thermodynamic properties of fcc Th as the entropy, the harmonic specific heat, the (P, V, T) equation of state and the thermal lattice expansion are found to be in a very good agreement with experiments and ab initio phonon calculations. The results of this work show the potentiality of the Chen-Moebius method coupled to ab initio calculation of the cohesive energy to develop a free-parameter pair potential capable of giving an overall description of fcc Th properties at T = 0 K with an error similar to ab initio calculations.

  11. [Nondestructive applanation technique to measure the elasticity moduli and creep properties of ocular cornea in vivo].

    Science.gov (United States)

    Zhang, Xueyong; Liu, Dong; Tang, Zhen; Liao, Rongfeng; Ma, Jianguo

    2015-02-01

    Due to lack of the practical technique to measure the biomechanical properties of the ocular cornea in vivo, clinical ophthalmologists have some difficulties in understanding the deformation mechanism of the cornea under the action of physiological intraocular pressures. Using Young's theory analysis of the corneal deformation during applanation tonometry, the relation between the elasticity moduli of the cornea and the applanated corneal area and the measured and true intraocular pressures can be obtained. A new applanation technique has been developed for measuring the biomechanical properties of the ocular cornea tissue in vivo, which can simultaneously acquire the data of the applanation area and displacement of the corneal deformation as well as the exerted applanation force on the cornea. Experimental results on a rabbit's eyeball demonstrated that the present technique could be used to measure the elasticity moduli and creep properties of the ocular cornea nondestructively in vivo.

  12. Frequency dependence of elastic properties of acoustic foams

    Science.gov (United States)

    Etchessahar, M.; Sahraoui, S.; Benyahia, L.; Tassin, J. F.

    2005-03-01

    Polyurethane (PU) and other plastic foams are widely used as passive acoustic absorbers. For optimal design, it is often necessary to know the viscoelastic properties of these materials in the frequency range relevant to their application. A nonresonance technique (dynamic stiffness) based on a forced vibrations procedure is used to investigate the frequency dependent complex shear modulus of a PU foam. This modulus is first measured, in a quasistatic configuration, in the frequency range (0.016-16 Hz) at different temperatures between 0 and 20 °C. It is afterwards predicted over a wide frequency range (0.01-3000 Hz) using the frequency-temperature superposition principle. The validation of this principle is discussed through quasistatic experiments. Under the assumption that Poisson's ratio of polymeric foams is real and frequency independent on the frequency range used, the frequency dependence of the complex shear modulus obtained is used to predict the complex stiffness of the acoustic foam on a wide frequency range. .

  13. Elastic Properties of Tricalcium Aluminate from High-Pressure Experiments and First-Principles Calculations

    KAUST Repository

    Moon, Juhyuk

    2012-06-04

    The structure and elasticity of tricalcium aluminate (C 3A) have been experimentally and theoretically studied. From high-pressure X-ray diffraction experiments, the bulk modulus of 102(6) and 110(3) GPa were obtained by fitting second- and third-order finite strain equation of state, respectively. First-principles calculations with a generalized gradient approximation gave an isotropic bulk modulus of 102.1 GPa and an isothermal bulk modulus of 106.0 GPa. The static calculations using the exchange-correlation functional show an excellent agreement with the experimental measurements. Based on the agreement, accurate elastic constants and other elastic moduli were computed. The slight difference of behavior at high pressure can be explained by the infiltration of pressure-transmitting silicone oil into structural holes in C 3A. The computed elastic and mechanical properties will be useful in understanding structural and mechanical properties of cementitious materials, particularly with the increasing interest in the advanced applications at the nanoscale. © 2012 The American Ceramic Society.

  14. Rheology Effects on Predicted Fiber Orientation and Elastic Properties in Large Scale Polymer Composite Additive Manufacturing

    Directory of Open Access Journals (Sweden)

    Zhaogui Wang

    2018-02-01

    Full Text Available Short fiber-reinforced polymers have recently been introduced to large-scale additive manufacturing to improve the mechanical performances of printed-parts. As the short fiber polymer composite is extruded and deposited on a moving platform, velocity gradients within the melt orientate the suspended fibers, and the final orientation directly affects material properties in the solidified extrudate. This paper numerically evaluates melt rheology effects on predicted fiber orientation and elastic properties of printed-composites in three steps. First, the steady-state isothermal axisymmetric nozzle melt flow is computed, which includes the prediction of die swell just outside the nozzle exit. Simulations are performed with ANSYS-Polyflow, where we consider the effect of various rheology models on the computed outcomes. Here, we include Newtonian, generalized Newtonian, and viscoelastic rheology models to represent the melt flow. Fiber orientation is computed using Advani–Tucker fiber orientation tensors. Finally, elastic properties in the extrudate are evaluated based from predicted fiber orientation distributions. Calculations show that the Phan–Thien–Tanner (PTT model yields the lowest fiber principal alignment among considered rheology models. Furthermore, the cross section averaged elastic properties indicate a strong transversely isotropic behavior in these composites, where generalized Newtonian models yield higher principal Young’s modulus, while the viscoelastic fluid models result in higher shear moduli.

  15. Recent developments in testing techniques for elastic mechanical properties of 1-D nanomaterials.

    Science.gov (United States)

    Wang, Weidong; Li, Shuai; Zhang, Hongti; Lu, Yang

    2015-01-01

    One-dimensional (1-D) nanomaterials exhibit great potentials in their applications to functional materials, nano-devices and systems owing to their excellent properties. In the past decade, considerable studies have been done, with new patents being developed, on these 1-D building blocks for for their mechanical properties, especially elastic properties, which provide a solid foundation for the design of nanoelectromechanical systems (NEMS) and predictions of reliability and longevity for their devices. This paper reviews some of the recent investigations on techniques as well as patents available for the quantitative characterization of the elastic behaviors of various 1-D nanomaterials, with particular focus on on-chip testing system. The review begins with an overview of major testing methods for 1-D nanostructures' elastic properties, including nanoindentation testing, AFM (atomic force microscopy) testing, in situ SEM (scanning electron microscopy) testing, in situ TEM (transmission electron microscopy) testing and the testing system on the basis of MEMS (micro-electro-mechanical systems) technology, followed by advantages and challenges of each testing approach. This review also focuses on the MEMS-based testing apparatus, which can be actuated and measured inside SEM and TEM with ease, allowing users to highly magnify the continuous images of the specimen while measuring load electronically and independently. The combination of on-chip technologies and the in situ electron microscopy is expected to be a potential testing technique for nanomechanics. Finally, details are presented on the key challenges and possible solutions in the implementation of the testing techniques referred above.

  16. Temperature-dependent elastic properties of brain tissues measured with the shear wave elastography method.

    Science.gov (United States)

    Liu, Yan-Lin; Li, Guo-Yang; He, Ping; Mao, Ze-Qi; Cao, Yanping

    2017-01-01

    Determining the mechanical properties of brain tissues is essential in such cases as the surgery planning and surgical training using virtual reality based simulators, trauma research and the diagnosis of some diseases that alter the elastic properties of brain tissues. Here, we suggest a protocol to measure the temperature-dependent elastic properties of brain tissues in physiological saline using the shear wave elastography method. Experiments have been conducted on six porcine brains. Our results show that the shear moduli of brain tissues decrease approximately linearly with a slope of -0.041±0.006kPa/°C when the temperature T increases from room temperature (~23°C) to body temperature (~37°C). A case study has been further conducted which shows that the shear moduli are insensitive to the temperature variation when T is in the range of 37 to 43°C and will increase when T is higher than 43°C. With the present experimental setup, temperature-dependent elastic properties of brain tissues can be measured in a simulated physiological environment and a non-destructive manner. Thus the method suggested here offers a unique tool for the mechanical characterization of brain tissues with potential applications in brain biomechanics research. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effect of alloying on elastic properties of ZrN based transition metal nitride alloys

    KAUST Repository

    Kanoun, Mohammed

    2014-09-01

    We report the effect of composition and metal sublattice substitutional element on the structural, elastic and electronic properties of ternary transition metal nitrides Zr1-xMxN with M=Al, Ti, Hf, V, Nb, W and Mo. The analysis of the elastic constants, bulk modulus, shear modulus, Young\\'s modulus, and Poisson\\'s ratio provides insights regarding the mechanical behavior of Zr1-xMxN. We predict that ternary alloys are more ductile compared to their parent binary compounds. The revealed trend in the mechanical behavior might help for experimentalists on the ability of tuning the mechanical properties during the alloying process by varying the concentration of the transition metal. © 2014 Elsevier B.V.

  18. Numerical homogenization of elastic and thermal material properties for metal matrix composites (MMC)

    Science.gov (United States)

    Schindler, Stefan; Mergheim, Julia; Zimmermann, Marco; Aurich, Jan C.; Steinmann, Paul

    2017-01-01

    A two-scale material modeling approach is adopted in order to determine macroscopic thermal and elastic constitutive laws and the respective parameters for metal matrix composite (MMC). Since the common homogenization framework violates the thermodynamical consistency for non-constant temperature fields, i.e., the dissipation is not conserved through the scale transition, the respective error is calculated numerically in order to prove the applicability of the homogenization method. The thermomechanical homogenization is applied to compute the macroscopic mass density, thermal expansion, elasticity, heat capacity and thermal conductivity for two specific MMCs, i.e., aluminum alloy Al2024 reinforced with 17 or 30 % silicon carbide particles. The temperature dependency of the material properties has been considered in the range from 0 to 500°C, the melting temperature of the alloy. The numerically determined material properties are validated with experimental data from the literature as far as possible.

  19. A Nonlinear Elastic Model for Triaxial Compressive Properties of Artificial Methane-Hydrate-Bearing Sediment Samples

    Directory of Open Access Journals (Sweden)

    Tsutomu Yamaguchi

    2012-10-01

    Full Text Available A constitutive model for marine sediments containing natural gas hydrate is essential for the simulation of the geomechanical response to gas extraction from a gas-hydrate reservoir. In this study, the triaxial compressive properties of artificial methane-hydrate-bearing sediment samples reported in an earlier work were analyzed to examine the applicability of a nonlinear elastic constitutive model based on the Duncan-Chang model. The presented model considered the dependences of the mechanical properties on methane hydrate saturation and effective confining pressure. Some parameters were decided depending on the type of sand forming a specimen. The behaviors of lateral strain versus axial strain were also formulated as a function of effective confining pressure. The constitutive model presented in this study will provide a basis for an elastic analysis of the geomechanical behaviors of the gas-hydrate reservoir in the future study, although it is currently available to a limited extent.

  20. Elastic and viscoelastic properties of porcine subdermal fat using MRI and inverse FEA.

    Science.gov (United States)

    Sims, A M; Stait-Gardner, T; Fong, L; Morley, J W; Price, W S; Hoffman, M; Simmons, A; Schindhelm, K

    2010-12-01

    There is a scarcity of investigation into the mechanical properties of subdermal fat. Recently, progress has been made in the determination of subdermal stress and strain distributions. This requires accurate constitutive modelling and consideration of the subdermal tissues. This paper reports the results of a study to estimate non-linear elastic and viscoelastic properties of porcine subdermal fat using a simple constitutive model. High-resolution magnetic resonance imaging (MRI) was used to acquire a time series of coincident images during a confined indentation experiment. Inverse finite element analysis was used to estimate the material parameters. The Neo Hookean model was used to represent the elastic behaviour (μ = 0.53 ± 0.31 kPa), while a single-element Prony series was used to model the viscoelastic response (α = 0.39 ± 0.03, τ = 700 ± 255 s).

  1. Structural, electronic and elastic properties of REIr2 (RE=La and Ce) Laves phase compounds

    Science.gov (United States)

    Shrivastava, Deepika; Fatima, Bushra; Sanyal, Sankar P.

    2016-05-01

    REIr2 (RE = La and Ce) Laves phase intermetallic compounds were investigated with respect to their structural, electronic and elastic properties using full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation (GGA) as implemented in WIEN2k code. The ground state properties such as lattice constants (a0), bulk modulus (B), pressure derivative of bulk modulus (Bꞌ) and density of state at Fermi level N(EF) have been obtained by optimization method. The electronic structure (BS, TDOS and PDOS) reveals that these Laves phase compounds are metallic in nature. The calculated elastic constants indicate that these compounds are mechanically stable at ambient pressure and found to be ductile in nature.

  2. THE ELASTIC AND THERMODYNAMIC PROPERTIES OF Lu DOPED ScVO3

    Science.gov (United States)

    Parveen, Atahar; Gaur, N. K.

    2012-12-01

    We have investigated the elastic, cohesive and thermal properties of (Lu, Sc) VO3 and Sc1-xLuxVO3(0.6 ≤ x ≤ 0.9) perovskites by means of a modified rigid ion model (MRIM). The variation of specific heat is determined following the temperature driven structural phase transitions. Also, the effect of lattice distortions on the elastic and thermal properties of the present pure and doped vanadates has been studied by an atomistic approach. The calculated bulk modulus (BT), reststrahlen frequency (ν0), cohesive energy (ϕ), Debye temperature (θD) and Gruneisen parameter (γ) reproduce well with the corresponding experimental data. The specific heat results can further be improved by including the magnetic ordering contributions to the specific heat.

  3. Properties of Waste Tire Rubber Powder

    Directory of Open Access Journals (Sweden)

    M. Bekhiti

    2014-08-01

    Full Text Available Scrap tires are abundant and alarming waste. The aggregates resulting from the crushing of the waste tires are more and more used in the field of civil engineering (geotechnical, hydraulic works, light concretes, asphaltic concretes, etc.. Depending on the type of the used tires, dimensions and possible separations and treatment, the physical and mechanical characteristics of these aggregates might change. Some physical, chemical and direct shear tests were performed on three gradation classes of waste tire rubber powder. The tests results were combined with data from previous studies to generate empirical relationships between cohesion, friction angle and particle size of waste tire powder rubber. A cubic (third order regression model seems to be more appropriate compared to linear and quadratic models.

  4. Improving mechanical properties of lightweight Porcelanite aggregate concrete using different waste material

    Directory of Open Access Journals (Sweden)

    Sheelan M. Hama

    2017-06-01

    Full Text Available Improving the mechanical properties of lightweight concrete using waste material is the goal of this work to get both structural and environmental advantage besides cost saving. Porcelanite aggregate was used as lightweight aggregate. First plastic bottles were cut into slices and used as fibers with these percentages: 0.0%, 0.5%, 0.75%, 1.0%, 1.25% and 1.5% by volume. The results of tests under compression and tensile stress showed that mix 1% plastic fiber (PF gave the best results when compared to reference mix without PF. Eggshell (rich with CaO and glass wastes (rich of silca were crashed and powdered to desired size and used as partial replacement of cement with these percentage: 0%, 5%, 10%, 15% and 20%. Compressive strength, flexural strength, density, absorption and modulus of elasticity were tested. Comparison was made with reference mix (without waste powder to figure the efficiency of using these waste in lightweight Porcelanite concrete. The results of tests showed that mixes with 1% PF and 5% eggshell powder (ESP gave results so close to reference mix. Using more than 5% ESP made no improvement in lightweight concrete, while the mix with 1% PF with any glass powder (GP percentages used in this research gave good improvement in the tested properties especially at 20% GP.

  5. Yttrium aluminium garnet under pressure: Structural, elastic, and vibrational properties from ab initio studies

    Energy Technology Data Exchange (ETDEWEB)

    Monteseguro, V. [Departamento de Física and MALTA Consolider Team, Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain); Rodríguez-Hernández, P.; Muñoz, A., E-mail: amunoz@ull.es [Departamento de Física and MALTA Consolider Team, Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain); Instituto de Materiales y Nanotecnología. Universidad de La Laguna, 38200 San Cristóbal de La Laguna, Santa Cruz de Tenerife (Spain)

    2015-12-28

    The structural, elastic, and vibrational properties of yttrium aluminum garnet Y{sub 3}Al{sub 5}O{sub 12} are studied under high pressure by ab initio calculations in the framework of the density functional theory. The calculated ground state properties are in good agreement with the available experimental data. Pressure dependences of bond length and bulk moduli of the constituent polyhedra are reported. The evolution of the elastic constants and the major elastic properties, Young and shear modulus, Poisson's ratios, and Zener anisotropy ratio, are described. The mechanical stability is analyzed, on the light of “Born generalized stability criteria,” showing that the garnet is mechanically unstable above 116 GPa. Symmetries, frequencies, and pressure coefficients of the Raman-active modes are discussed on the basis of the calculated total and partial phonon density of states, which reflect the dynamical contribution of each atom. The relations between the phonon modes of Y{sub 3}Al{sub 5}O{sub 12} and the internal and external molecular modes of the different polyhedra are discussed. Infrared-active modes, as well as the silent modes, and their pressure dependence are also investigated. No dynamical instabilities were found below 116 GPa.

  6. Effects of alloying elements on elastic properties of Al by first-principles calculations

    Directory of Open Access Journals (Sweden)

    Wang J.

    2014-01-01

    Full Text Available The effects of alloying elements (Co, Cu, Fe, Ge, Hf, Mg, Mn, Ni, Si, Sr, Ti, V, Y, Zn, and Zr on elastic properties of Al have been investigated using first-principles calculations within the generalized gradient approximation. A supercell consisting of 31 Al atoms and one solute atom is used. A good agreement is obtained between calculated and available experimental data. Lattice parameters of the studied Al alloys are found to be depended on atomic radii of solute atoms. The elastic properties of polycrystalline aggregates including bulk modulus (B, shear modulus (G, Young’s modulus (E, and the B/G ratio are also determined based on the calculated elastic constants (cij’s. It is found that the bulk modulus of Al alloys decreases with increasing volume due to the addition of alloying elements and the bulk modulus is also related to the total molar volume (Vm and electron density (nAl31x with the relationship of nAl31x=1.0594+0.0207√B/Vm. These results are of relevance to tailor the properties of Al alloys.

  7. Ab initio study of thermodynamic, electronic, magnetic, structural, and elastic properties of Ni4N allotropes

    Science.gov (United States)

    Hemzalová, P.; Friák, M.; Šob, M.; Ma, D.; Udyansky, A.; Raabe, D.; Neugebauer, J.

    2013-11-01

    We have employed parameter-free density functional theory calculations to study the thermodynamic stability and structural parameters as well as elastic and electronic properties of Ni4N in eight selected crystallographic phases. In agreement with the experimental findings, the cubic structure with Pearson symbol cP5, space group Pm3¯m (221) is found to be the most stable and it is also the only thermodynamically stable structure at T=0 K with respect to decomposition to the elemental Ni crystal and N2 gas phase. We determine structural parameters, bulk moduli, and their pressure derivatives for all eight allotropes. The thermodynamic stability and bulk modulus is shown to be anticorrelated. Comparing ferromagnetic and nonmagnetic states, we find common features between the magnetism of elemental Ni and studied ferromagnetic Ni4N structures. For the ground-state Ni4N structure and other two Ni4N cubic allotropes, we predict a complete set of single-crystalline elastic constants (in the equilibrium and under hydrostatic pressure), the Young and area moduli, as well as homogenized polycrystalline elastic moduli obtained by different homogenization methods. We demonstrate that the elastic anisotropy of the ground-state Ni4N is qualitatively opposite to that in the elemental Ni, i.e., these materials have hard and soft crystallographic directions interchanged. Moreover, one of the studied metastable cubic phases is found auxetic, i.e., exhibiting negative Poisson ratio.

  8. Effect of temperature and geometric parameters on elastic properties of tungsten nanowire: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Sourav, E-mail: ssaha09@me.buet.ac.bd; Mojumder, Satyajit; Mahboob, Monon [Department of Mechanical Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000 (Bangladesh); Islam, M. Zahabul [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2016-07-12

    Tungsten is a promising material and has potential use as battery anode. Tungsten nanowires are gaining attention from researchers all over the world for this wide field of application. In this paper, we investigated effect of temperature and geometric parameters (diameter and aspect ratio) on elastic properties of Tungsten nanowire. Aspect ratios (length to diameter ratio) considered are 8:1, 10:1, and 12:1 while diameter of the nanowire is varied from 1-4 nm. For 2 nm diameter sample (aspect ratio 10:1), temperature is varied (10 K ~ 1500 K) to observe elastic behavior of Tungsten nanowire under uniaxial tensile loading. EAM potential is used for molecular dynamic simulation. We applied constant strain rate of 10{sup 9} s{sup −1} to deform the nanowire. Elastic behavior is expressed through stress vs. strain plot. We also investigated the fracture mechanism of tungsten nanowire and radial distribution function. Investigation suggests peculiar behavior of Tungsten nanowire in nano-scale with double peaks in stress vs. strain diagram. Necking before final fracture suggests that actual elastic behavior of the material is successfully captured through atomistic modeling.

  9. The relationship between dermal papillary structure and skin surface properties, color, and elasticity.

    Science.gov (United States)

    Mizukoshi, K; Nakamura, T; Oba, A

    2016-08-01

    The skin contains an undulating structure called the dermal papillary structure between the border of the epidermis and dermis. The physiological importance of the dermal papillary structures has been discussed, however, the dermal papillary structures have never been evaluated for their contribution to skin appearance. In this study, we investigated the correlation between the dermal papillary structure and skin color and elasticity. In addition, the relationship was validated with skin model experiments. The dermal papillary structures in the skin of the female cheek were quantitatively measured by in vivo confocal laser scanning microscopy images. In addition, the skin color and elasticity were measured at the same site. A skin model with dermal papilla-like structures was created by referring to the optical and shape properties of the skin using agar gel and a scattering sheet. Correlations were found between the dermal papillary structures and skin color irregularity and skin elasticity. These relationships were verified by the experiments employing a skin model. The results of this study indicated that the dermal papillary structure is also an important factor for skin appearance such as color and elasticity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. First-principles study on mechanical and elastic properties of BxAl1-xP alloys

    Directory of Open Access Journals (Sweden)

    Huihui Ma

    2017-06-01

    Full Text Available Based on density functional theory calculations, systematic calculations of the structural properties, elastic anisotropy and mechanical properties of boron alloying aluminum phosphide (BxAl1-xP ternary mixed crystal have been presented. The results of the lattice parameters, band gaps, elastic constants and elastic modulus accord with the experimental and others published data well. The band structure which is described by CASTEP method indicates they are direct gap semiconductors for the composition x = 0.25, 0.50 and 0.75. Beyond that, we studied the Debye temperatures together with the acoustic velocities for all the BxAl1-xP alloys using the obtained elastic modulus. Finally, we depicted the three dimensional surface constructions to explain the elastic anisotropy using several calculated different anisotropic indexes in our work.

  11. Elastic and piezoelectric properties of zincblende and wurtzite crystalline nanowire heterostructures.

    Science.gov (United States)

    Boxberg, Fredrik; Søndergaard, Niels; Xu, H Q

    2012-09-04

    The elastic and piezoelectric properties of zincblende and wurtzite crystalline InAs/InP nanowire heterostructures have been studied using electro-elastically coupled continuum elasticity theory. A comprehensive comparison of strains, piezoelectric potentials and piezoelectric fields in the two crystal types of nanowire heterostructures is presented. For each crystal type, three different forms of heterostructures-core-shell, axial superlattice, and quantum dot nanowire heterostructures-are considered. In the studied nanowire heterostructures, the principal strains are found to be insensitive to the change in the crystal structure. However, the shear strains in the zincblende and wurtzite nanowire heterostructures can be very different. All the studied nanowire heterostructures are found to exhibit a piezoelectric field along the nanowire axis. The piezoelectric field is in general much stronger in a wurtzite nanowire heterostructure than in its corresponding zincblende heterostructure. Our results are expected to be particularly important for analyzing and understanding the properties of epitaxially grown nanowire heterostructures and for applications in nanowire electronics, optoelectronics, and biochemical sensing. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Elastic and piezoelectric properties of zincblende and wurtzite crystalline nanowire heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Boxberg, Fredrik [Division of Solid State Physics, Lund University (Sweden); Soendergaard, Niels [Division of Mathematical Physics, Lund University (Sweden); Xu, H.Q. [Department of Electronics and Key Laboratory for the Physics and Chemistry of Nanodevices, Peking University, Beijing (China); Division of Solid State Physics, Lund University (Sweden)

    2012-09-04

    The elastic and piezoelectric properties of zincblende and wurtzite crystalline InAs/InP nanowire heterostructures have been studied using electro-elastically coupled continuum elasticity theory. A comprehensive comparison of strains, piezoelectric potentials and piezoelectric fields in the two crystal types of nanowire heterostructures is presented. For each crystal type, three different forms of heterostructures - core-shell, axial superlattice, and quantum dot nanowire heterostructures - are considered. In the studied nanowire heterostructures, the principal strains are found to be insensitive to the change in the crystal structure. However, the shear strains in the zincblende and wurtzite nanowire heterostructures can be very different. All the studied nanowire heterostructures are found to exhibit a piezoelectric field along the nanowire axis. The piezoelectric field is in general much stronger in a wurtzite nanowire heterostructure than in its corresponding zincblende heterostructure. Our results are expected to be particularly important for analyzing and understanding the properties of epitaxially grown nanowire heterostructures and for applications in nanowire electronics, optoelectronics, and biochemical sensing. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Effects of compositions of filler, binder and porosity on elastic and fracture properties of nuclear graphite

    Energy Technology Data Exchange (ETDEWEB)

    Kyaw, S.T., E-mail: si.kyaw@nottingham.ac.uk; Sun, W.; Becker, A.A.

    2015-02-15

    Highlights: • Micromechanics based homogenisation method is used for graphite microstructures. • Elastic and fracture properties are estimated based on graphite microstructures. • Fracture behaviours are studied using compact tension simulation. • Fracture behaviours are studied using four point bending simulation. • Flexural strengths were obtained and compared to experimental results from literature. - Abstract: Physical mechanisms at different length scales have to be taken into account while predicting the overall failure of nuclear graphite structures of advanced gas cooled graphite reactors. In this paper, the effect of composition of meso graphite phases and porosity on the aggregate elastic properties is predicted using the Eshelby homogenisation method. Results indicate an overall decrease in elastic modulus with an increase in porosity. Subsequently, the moduli at different porosity levels are used to predict the critical strain energy release rates for crack propagation of graphite, and fracture behaviour is studied using compact tension and four point bending tests. Compared to flexural strength at zero porosity level, significant reduction in strength of up to 80% at 30% porosity level is observed. Evolution of flexural strength due to porosity is also compared against available experimental values of graphite from UK nuclear plants.

  14. Variability in the elastic properties of bovine dentin at multiple length scales.

    Science.gov (United States)

    Deymier-Black, A C; Almer, J D; Stock, S R; Dunand, D C

    2012-01-01

    Various methods are used to investigate the variability in elastic properties across a population of deciduous bovine incisor root dentin samples spanning different animals, incisor types, and locations within teeth. First, measurements of elastic strains by high-energy synchrotron X-ray scattering during compressive loading of dentin specimens provided the effective modulus--the ratio of applied stress to elastic phase strain--for the two main phases of dentin (hydroxyapatite crystals and mineralized collagen fibrils), shedding light on load transfer operating at the nanoscale between collagen and mineral phases. Second, Young's moduli were measured at the macroscale by ultrasonic time-of-flight measurements. Third, thermogravimetry quantified the volume fractions of hydroxyapatite, protein and water at the macroscale. Finally, micro-Computed Tomography determined spatial variations of the mineral at the sub-millimeter scale. Statistical comparison of the above properties reveals: (i) no significant differences for dentin samples taken from different animals or different incisor types but (ii) significant differences for samples taken from the cervical or apical root sections as well as from different locations between buccal and lingual edges. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. First principles investigation of the structure, elasticity, and vibrational property of the serpentine minerals. (Invited)

    Science.gov (United States)

    Tsuchiya, J.; Tsuchiya, T.

    2013-12-01

    Serpentine is formed by reaction between peridotite and water which is released from hydrous mineral in subducting slab under pressure. Partially serpentinized peridotite may be a significant reservoir for water in the subducted cold slab and is considered to play an important role in subduction zone processes such as generation of arc magmatism. Precise determination of structure, vibrational and elastic properties of serpentine become the basis for understanding the transporting processes of water into deep Earth interior. Here we investigate by first principles calculation, the detailed structures, vibrational and elastic properties of lizardite, chlorite, and antigorite which are major hydrous minerals in the serpentinized peridotite. We found a very sudden softening of the elastic constants at high pressure condition. This anomaly is associated with a slight change in the compressibility of the c axis which corresponds to the layer normal direction. The calculated OH stretching frequencies also increase suddenly associated with the anomaly and these vibrational behaviors are consistent with the previous Raman measurements. Since other hydrous phyllosilicates such as clay minerals, and mica have similar crystal structures to these hydrous minerals, these anomalous softening is also expected in these minerals under pressure. Research supported in part by special coordination funds for promoting science and technology (Supporting Young Researchers with Fixed-term Appointments) and Grants-In-Aid for Scientific Research from the Japan Society for the Promotion of Science (Nos. 21740380, 20103005, and 24740357).

  16. Molecular dynamics investigation of the elastic and fracture properties of the R-graphyne under uniaxial tension

    Energy Technology Data Exchange (ETDEWEB)

    Rouhi, Saeed, E-mail: s_rouhi@iaul.ac.ir

    2017-05-15

    In this paper, the mechanical properties of the R-graphynes are investigated by using molecular dynamics simulations. For this purpose, the uniaxial strain is applied on the nanosheets. The effects of R-graphyne chirality and dimension on their fracture and elastic properties are investigated. It is shown that the fracture properties of the armchair R-graphyne are approximately independent from the nanosheet sizes. However, a clear dependence is observed in the fracture properties of the zigzag R-graphyne on the nanosheet dimensions. Comparing the elastic modulus of the armchair and zigzag R-graphynes, it is shown that for the same sizes, the elastic modulus of armchair R-graphyne is approximately equal to 2.5 times of the elastic modulus of the zigzag ones. Pursuing the fracture process of R-graphynes with different chiralities, it is represented that the fracture propagates in the zigzag nanosheet with a higher velocity than the armchair ones.

  17. Nanotechnology and construction: use of nanoindentation measurements to predict macroscale elastic properties of high strength cementitious composites

    Directory of Open Access Journals (Sweden)

    W. R. L. da Silva

    Full Text Available This paper aims to present the experimental results involving the use of nanoindentation measurements and prediction of macroscale elastic properties of high performance cementitious composites (HPCC. The elastic properties of HPCC mixture were evaluated at different length scales by nanoindentation (microscale, and elastic moduli and compressive strength tests (macroscale. The nanoindentation results, obtained by grid indentation with subsequent phase deconvolution, were complemented by an independent porosimetry test and inserted into a two-step analytical homogenization scheme to predict the overall macroscale properties. The final results show that the presented method allows a reliable advanced prediction of HPCC elastic properties indicating, thus, that inserting nanotechnology in the concrete industry can be promising, since it would allow the production of a more predictable composite in an easier and less expensive way.

  18. Achilles tendon elastic properties remain decreased in long term after rupture.

    Science.gov (United States)

    Frankewycz, B; Penz, A; Weber, J; da Silva, N P; Freimoser, F; Bell, R; Nerlich, M; Jung, E M; Docheva, D; Pfeifer, C G

    2017-11-16

    Rupture of the Achilles tendon results in inferior scar tissue formation. Elastography allows a feasible in vivo investigation of biomechanical properties of the Achilles tendon. The purpose of this study is to investigate the biomechanical properties of healed Achilles tendons in the long term. Patients who suffered from Achilles tendon rupture were recruited for an elastographic evaluation. Unilateral Achilles tendon ruptures were included and scanned in the mid-substance and calcaneal insertion at least 2 years after rupture using shear wave elastography. Results were compared to patients' contralateral non-injured Achilles tendons and additionally to a healthy population. Descriptive statistics, reliability analysis, and correlation analysis with clinical scores were performed. Forty-one patients were included in the study with a mean follow-up-time of 74 ± 30; [26-138] months after rupture. Significant differences were identified in shear wave elastography in the mid-substance of healed tendons (shear wave velocity 1.2 ±1.5 m/s) compared to both control groups [2.5 ±1.5 m/s (p Achilles tendon after rupture has inferior elastic properties even after a long-term healing phase. Differences in elastic properties after rupture mainly originate from the mid-substance of the Achilles tendon, in which most of the ruptures occur. Elastographic results do not correspond with subjective perception. Clinically, sonoelastographical measurements of biomechanical properties can be useful to provide objective insights in tendon recovery.

  19. Electronic band structure, stability, structural, and elastic properties of IrTi alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chen Wenzhou; Li Qian [Institute of Modern Physics, Northwest University, Xi' an 710069 (China); Jiang Zhenyi, E-mail: jiangzy@nwu.edu.cn [Institute of Modern Physics, Northwest University, Xi' an 710069 (China); Zhang Xiaodong; Si Liang [Institute of Modern Physics, Northwest University, Xi' an 710069 (China); Li Lisha [Department of Physics, Northwest University, Xi' an 710069 (China); Wu Rui [Institute of Modern Physics, Northwest University, Xi' an 710069 (China)

    2012-07-15

    The structural properties and mechanical stabilities of B2-IrTi have been investigated using first-principle calculations. The elastic constants calculations indicate that the B2-IrTi is unstable to external strain and the softening of C{sub 11}-C{sub 12} triggers the B2-IrTi (cubic) to L1{sub 0}-IrTi (tetragonal) phase transformation. Detailed electronic structure analysis revealed a Jahn-Teller-type band split that could be responsible for elastic softening and structure phase transition. The cubic-tetragonal transition is accompanied by a reduction in the density of states (DOS) at the Fermi level and the d-DOS of Ti at Fermi level plays a decisive role in destabilizing the B2-IrTi phase.

  20. Flexoelectricity and thermal fluctuations of lipid bilayer membranes: Renormalization of flexoelectric, dielectric, and elastic properties

    Science.gov (United States)

    Liu, L. P.; Sharma, P.

    2013-03-01

    Thermal fluctuations renormalize the bending elasticity of lipid bilayers. This well-studied effect is a cornerstone in the study of several membrane biophysical phenomena. Analogously, nearly all membranes are endowed with an electromechanical coupling called flexoelectricity that admits membrane polarization due to curvature changes. Flexoelectricity is found to be important in a number of biological functions, including hearing, ion transport, and in some situations where mechanotransduction is necessary. Very little is known about the interplay between thermal fluctuations and flexoelectricity. In this work, we explore how the apparent flexoelectricity is altered due to thermal fluctuations and, further, how the elastic and dielectric properties are renormalized due to flexoelectricity. We find that the apparent bending rigidity is softened by flexoelectricity and discuss the ramifications for interpreting existing experimental work.

  1. Structural, elastic, electronic and magnetic properties of Fe3AC; A = Al, Ga and In

    Directory of Open Access Journals (Sweden)

    Medkour Y.

    2013-09-01

    Full Text Available We report first principle calculations on the structural, electronic and magnetic properties of antiperovskite Fe3AC; A = Al, Ga and In. Calculations show that these compounds are more stable in the magnetic states, the estimated equilibrium lattice parameters (a and V are in agreement with the experimental data. From the single crystal elastic constants, the polycrystalline elastic moduli is estimated. Similar to previous studies on carbides antiperovskite, these compounds are good electrical conductors. The analysis of the total and partial densities of states shows that the conductivity is assured by d electrons of the transition metal atoms. The magnetic character in these compounds is mainly related to the spin polarization of Fe-d electrons. The magnetic moment per unit formula is found to decrease from 3.52 μB to 3.06 μB corresponding to Fe3InC and Fe3AlC respectively.

  2. Al4SiC4 wurtzite crystal: Structural, optoelectronic, elastic, and piezoelectric properties

    Directory of Open Access Journals (Sweden)

    L. Pedesseau

    2015-12-01

    Full Text Available New experimental results supported by theoretical analyses are proposed for aluminum silicon carbide (Al4SiC4. A state of the art implementation of the density functional theory is used to analyze the experimental crystal structure, the Born charges, the elastic properties, and the piezoelectric properties. The Born charge tensor is correlated to the local bonding environment for each atom. The electronic band structure is computed including self-consistent many-body corrections. Al4SiC4 material properties are compared to other wide band gap wurtzite materials. From a comparison between an ellipsometry study of the optical properties and theoretical results, we conclude that the Al4SiC4 material has indirect and direct band gap energies of about 2.5 eV and 3.2 eV, respectively.

  3. Sound insulation properties of structure designed from apparel cutting waste

    OpenAIRE

    Jordeva, Sonja; Tomovska, Elena; Trajković, Dušan; Popeski-Dimovski, Riste; Zafirova, Koleta

    2015-01-01

    In this paper an insulation structure from apparel cutting waste was designed and its sound insulation properties were investigated. Shredded polyester apparel cuttings were used as the raw material for an insulation structure. The obtained results show that the insulation structure made from apparel cutting waste has good sound absorption compared to standard sound and thermal insulators. The average sound absorption of the samples was from 54.7% to 74.7%, for a frequency range of 250-2000Hz...

  4. Properties of vitrified rocky flats TRUW with different waste loadings

    Energy Technology Data Exchange (ETDEWEB)

    Eddy, T.L.; Sears, J.W.; Grandy, J.D.; Miley, D.V.; Erickson, A.W.; Farnsworth, R.N.; Larsen, E.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-12-31

    Leach rates, phase structures, and mechanical properties of simulated Rocky Flats Plant 1st and 2nd slate sludge vitrified in an arc melter are described as a function of waste to soil fraction and method of devitrification to produce the glass-ceramic waste form. Volatile, hazardous, and transuranic (TRU) surrogate metals were added to assess dissolution effects. Zirconia and titania were also added to confirm their ability as transuranic-surrogate getters.

  5. Multiscale Evaluation of the Nonlinear Elastic Properties of Carbon Nanotubes Under Finite Deformation

    Directory of Open Access Journals (Sweden)

    Abolfazl Shahabodini

    2017-06-01

    Full Text Available This paper deals with the calculation of the elastic properties for single-walled carbon nanotubes (SWCNTs under axial deformation and hydrostatic pressure using the atomistic-based continuum approach and the deformation mapping technique. A hyperelastic model based on the higher-order Cauchy-Born (HCB rule being applicable at finite strains and accounting for the chirality and material nonlinearity is presented. Mechanical properties of several carbon nanotubes (CNTs are computed and compared with the existing theoretical results and a good agreement is observed. Moreover, by comparison with atomistic calculations, it is found that the present model can reproduce the energetics of axially deformed CNTs. The model is then adopted to study the dependence of the elastic properties on chirality, radius and strain which yields an upper bound on the stability limit of axially and circumferentially stretched nanotubes. The influence of chirality is found to be more prominent for smaller tubes and as the diameter increases, the anisotropy induced by finite deformations gets nullified. It is discerned that the constitutive properties of the CNT can vary with deformation in a nonlinear manner. It is also found that the CNT displays a martial softening behavior at finite tensile strains and a hardening behavior at slightly compressive strains.

  6. Identification of material properties of orthotropic elastic cylinders immersed in fluid using vibroacoustic techniques.

    Science.gov (United States)

    Rosario, Daniel E; Brigham, John C; Aquino, Wilkins

    2008-11-01

    A numerical study is presented to show the potential for using vibroacoustic-based experiments to identify elastic material properties of orthotropic cylindrical vessels immersed in fluids. Sensitivity analyses and a simulated inverse problem are shown to quantify the potential for material characterization through the use of acoustic emissions. For comparison purposes, the analyses are also shown with the normal component of the velocity at the surface of the cylinder as the measured response in place of the acoustic pressure. The simulated experiment consisted of an orthotropic cylinder immersed in water with an impact force applied to the surface of the cylinder. The material parameters of the cylinder considered in the analyses were the circumferential and longitudinal elastic moduli, and the in-plane shear modulus. The velocity response is shown to provide sufficient information for characterizing all three moduli from a single experiment. Alternatively, the acoustic pressure response is shown to provide sufficient information for characterizing only the two elastic moduli from a single experiment. The analyses show that the acoustic pressure response does not have sufficient sensitivity to the in-plane shear modulus for characterization purposes.

  7. Rheological properties of kaolin and chemically simulated waste

    Energy Technology Data Exchange (ETDEWEB)

    Selby, C.L.

    1981-12-01

    The Savannah River Laboratory is conducting tests to determine the best operating conditions of pumps used to transfer insoluble radioactive sludges from old to new waste tanks. Because it is not feasible to conduct these tests with real or chemically simulated sludges, kaolin clay is being used as a stand-in for the solid waste. The rheology tests described herein were conducted to determine whether the properties of kaolin were sufficiently similar to those of real sludge to permit meaningful pump tests. The rheology study showed that kaolin can be substituted for real waste to accurately determine pump performance. Once adequately sheared, kaolin properties were found to remain constant. Test results determined that kaolin should not be allowed to settle more than two weeks between pump tests. Water or supernate from the waste tanks can be used to dilute sludge on an equal volume basis because they identically affect the rheological properties of sludge. It was further found that the fluid properties of kaolin and waste are insensitive to temperature.

  8. Effect of Neodymium Nanoparticles on Elastic Properties of Zinc-Tellurite Glass System

    Directory of Open Access Journals (Sweden)

    Abdulbaset A. Abdulla Awshah

    2017-01-01

    Full Text Available The aim of this work is to determine the effect of neodymium nanoparticles concentration on the elastic properties of zinc-tellurite glass. A series of neodymium nanoparticles doped zinc-tellurite glass systems (NdNPsZT of composition [(TeO20.70(ZnO0.30]1-x(Nd2O3 NPs(x, x=0.01, 0.02, 0.03, 0.04, and 0.05, were synthesized by using conventional melt-quenching method. The amorphous nature of the glass system was confirmed by using XRD analysis. The density of the glass system was determined by Archimedes method. The elastic properties were calculated from the measured density and ultrasonic velocity at 5 MHz frequency. The experimental results showed that the elastic properties rely upon the composition of the glass systems and the impact of neodymium nanoparticles (Nd2O3 NPs within the glass network. The increase in ultrasonic velocities is due to the increase in rigidity and change in structural units of the glass system. The softening temperature and the microhardness increased with the increase in Nd3+ ions concentration from 0.1 to 0.2 mol and decreased when the Nd3+ ions concentration increased from 0.2 to 0.5 mol. Poisson’s ratio and Debye’s temperature decreased with the increase in the Nd3+ ions concentration from 0.1 to 0.2 mol and increased when the Nd3+ ions concentration was increased from 0.2 to 0.5 mol.

  9. Structural, elastic, electronic, and thermodynamic properties of MgAgSb investigated by density functional theory

    Science.gov (United States)

    Wang, Jun-Fei; Fu, Xiao-Nan; Zhang, Xiao-Dong; Wang, Jun-Tao; Li, Xiao-Dong; Jiang, Zhen-Yi

    2016-08-01

    The structural, elastic, electronic, and thermodynamic properties of thermoelectric material MgAgSb in γ,β,α phases are studied with first-principles calculations based on density functional theory. The optimized lattice constants accord well with the experimental data. According to the calculated total energy of the three phases, the phase transition order is determined from α to γ phase with cooling, which is in agreement with the experimental result. The physical properties such as elastic constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and anisotropy factor are also discussed and analyzed, which indicates that the three structures are mechanically stable and each has a ductile feature. The Debye temperature is deduced from the elastic properties. The total density of states (TDOS) and partial density of states (PDOS) of the three phases are investigated. The TDOS results show that the γ phase is most stable with a pseudogap near the Fermi level, and the PDOS analysis indicates that the conduction band of the three phases is composed mostly of Mg-3s, Ag-4d, and Sb-5p. In addition, the changes of the free energy, entropy, specific heat, thermal expansion of γ-MgAgSb with temperature are obtained successfully. The obtained results above are important parameters for further experimental and theoretical tuning of doped MgAgSb as a thermoelectric material at high temperature. Project supported by the National Natural Science Foundation of China (Grant No. 11504088), the Fund from Henan University of Technology, China (Grant Nos. 2014YWQN08 and 2013JCYJ12), the Natural Science Fund from the Henan Provincial Education Department, China (Grant No. 16A140027), the Natural Science Foundation of Shaanxi Province of China (Grant Nos. 2013JQ1018 and 15JK1759), and the Science Foundation of Northwest University of China (Grant No. 14NW23).

  10. Influence of exogenous pigmentation on the optical properties of orthodontic elastic ligatures

    Directory of Open Access Journals (Sweden)

    Alline Birra Nolasco Fernandes

    2012-08-01

    Full Text Available OBJECTIVES: The aim of this study was to assess the optical properties of orthodontic elastic ligatures under the influence of exogenous pigments contained in the daily diet. MATERIAL AND METHODS: For the analysis, colorless (clear elastic segments (ORTHO Organizers, lot 660625A10 were used as received from the manufacturer, and were divided into 8 groups of 3 segments each. Each group was immersed in 200 mL of a solution containing a determined substance, as follows: distilled water (control group, Coca-Cola®, Pomarola brand tomato sauce (Cica®, açai, Jasmine® brand green tea, Royal Blend® black tea brand, Pilão® brand coffee and Palmares® wine brand. All test specimens were immersed in the solutions and kept in an appropriate receptacle for 7 days at 37°C14. After the staining session, the test specimens were washed with distilled water in an ultrasonic vat for 5 min and dried with paper tissues6. The portable digital spectrophotometer Vita Easyshade Compact was used to assess if there was color variation of the test specimens. This variation was quantified and qualified at the initial time (T0 and after staining (T1. RESULTS: These results were analyzed statistically using the software SPSS version 18.0. The Shapiro-Wilk test of normality was applied followed by the one-way analysis of variance and the Tukey's post hoc test. The level of significance adopted was 5%. CONCLUSIONS: From the substances evaluated in this study, those with higher staining potential on esthetic elastic ligatures were black tea, coffee and wine, respectively. Knowing this information, the dentist may advise their patients to avoid certain foods because of elastic staining may occur thus decreasing the aesthetics of the material.

  11. Elastic and Piezoelectric Properties of Boron Nitride Nanotube Composites. Part II; Finite Element Model

    Science.gov (United States)

    Kim, H. Alicia; Hardie, Robert; Yamakov, Vesselin; Park, Cheol

    2015-01-01

    This paper is the second part of a two-part series where the first part presents a molecular dynamics model of a single Boron Nitride Nanotube (BNNT) and this paper scales up to multiple BNNTs in a polymer matrix. This paper presents finite element (FE) models to investigate the effective elastic and piezoelectric properties of (BNNT) nanocomposites. The nanocomposites studied in this paper are thin films of polymer matrix with aligned co-planar BNNTs. The FE modelling approach provides a computationally efficient way to gain an understanding of the material properties. We examine several FE models to identify the most suitable models and investigate the effective properties with respect to the BNNT volume fraction and the number of nanotube walls. The FE models are constructed to represent aligned and randomly distributed BNNTs in a matrix of resin using 2D and 3D hollow and 3D filled cylinders. The homogenisation approach is employed to determine the overall elastic and piezoelectric constants for a range of volume fractions. These models are compared with an analytical model based on Mori-Tanaka formulation suitable for finite length cylindrical inclusions. The model applies to primarily single-wall BNNTs but is also extended to multi-wall BNNTs, for which preliminary results will be presented. Results from the Part 1 of this series can help to establish a constitutive relationship for input into the finite element model to enable the modeling of multiple BNNTs in a polymer matrix.

  12. Elastic properties of Ca-based metallic glasses predicted by first-principles simulations

    Energy Technology Data Exchange (ETDEWEB)

    Widom, M.; Sauerwine, B.; Cheung, A.M.; Poon, S.J.; Tong, P.; Louca, D.; Shiflet, G.J. (CM); (UV)

    2012-07-11

    First-principles simulations of Ca-based metallic glass-forming alloys yield sample amorphous structures whose structures can be compared to experiment and whose properties can be analyzed. In an effort to understand and control ductility, we investigate the elastic moduli. Calculated Poisson ratios depend strongly on alloying elements in a manner that correlates with ionicity (charge transfer). Consequently, we predict that alloying Ca with Mg and Zn should result in relatively ductile glasses compared to alloying with Ag, Cu, or Al. Experimental observations validate these predictions.

  13. Properties of dune sand concrete containing coffee waste

    Directory of Open Access Journals (Sweden)

    Mohamed Guendouz

    2018-01-01

    Full Text Available In the last years, an increase of coffee beverages consumption has been observed all over the world; and its consumption increases the waste coffee grounds which will become an environmental problems. Recycling of this waste to produce new materials like sand concrete appears as one of the best solutions for reduces the problem of pollution. This work aims to study the possibility of recycling waste coffee grounds (Spent Coffee Grounds (SCG as a fine aggregate by replacing the sand in the manufacturing of dune sand concrete. For this; sand concrete mixes were prepared with substitution of sand with the spent coffee grounds waste at different percentage (0%, 5%, 10%, 15% and 20% by volume of the sand in order to study the influence of this wastes on physical (Workability, bulk density and porosity, mechanical (compressive and flexural strength and Thermal (Thermal conductivity and thermal diffusivity properties of dune sand concrete. The results showed that the use of spent coffee grounds waste as partial replacement of natural sand contributes to reduce workability, bulk density and mechanical strength of sand concrete mixes with an increase on its porosity. However, the thermal characteristics are improved and especially for a level of 15% and 20% of substitution. So, it is possible to obtain an insulating material which can be used in the various types of structural components. This study ensures that reusing of waste coffee grounds in dune sand concrete gives a positive approach to reduce the cost of materials and solve some environmental problems.

  14. High pressure structural, elastic and vibrational properties of green energetic oxidizer ammonium dinitramide

    Science.gov (United States)

    Yedukondalu, N.; Ghule, Vikas D.; Vaitheeswaran, G.

    2016-08-01

    Ammonium DiNitramide (ADN) is one of the most promising green energetic oxidizers for future rocket propellant formulations. In the present work, we report a detailed theoretical study on structural, elastic, and vibrational properties of the emerging oxidizer under hydrostatic compression using various dispersion correction methods to capture weak intermolecular (van der Waals and hydrogen bonding) interactions. The calculated ground state lattice parameters, axial compressibilities, and equation of state are in good accord with the available experimental results. Strength of intermolecular interactions has been correlated using the calculated compressibility curves and elastic moduli. Apart from this, we also observe discontinuities in the structural parameters and elastic constants as a function of pressure. Pictorial representation and quantification of intermolecular interactions are described by the 3D Hirshfeld surfaces and 2D finger print maps. In addition, the computed infra-red (IR) spectra at ambient pressure reveal that ADN is found to have more hygroscopic nature over Ammonium Perchlorate (AP) due to the presence of strong hydrogen bonding. Pressure dependent IR spectra show blue- and red-shift of bending and stretching frequencies which leads to weakening and strengthening of the hydrogen bonding below and above 5 GPa, respectively. The abrupt changes in the calculated structural, mechanical, and IR spectra suggest that ADN might undergo a first order structural transformation to a high pressure phase around 5-6 GPa. From the predicted detonation properties, ADN is found to have high and low performance characteristics (DCJ = 8.09 km/s and PCJ = 25.54 GPa) when compared with ammonium based energetic oxidizers (DCJ = 6.50 km/s and PCJ = 17.64 GPa for AP, DCJ = 7.28 km/s and PCJ = 18.71 GPa for ammonium nitrate) and well-known secondary explosives for which DCJ = ˜8-10 km/s and PCJ = ˜30-50 GPa, respectively.

  15. Ab initio study of electronic structure, elastic and optical properties of anti-perovskite type alkali metal oxyhalides

    Science.gov (United States)

    Ramanna, J.; Yedukondalu, N.; Ramesh Babu, K.; Vaitheeswaran, G.

    2013-06-01

    We report the structural, elastic, electronic, and optical properties of antiperovskite alkali metal oxyhalides Na3OCl, Na3OBr, and K3OBr using two different density functional methods within generalized gradient approximation (GGA). Plane wave pseudo potential (PW-PP) method has been used to calculate the ground state structural and elastic properties while the electronic structure and optical properties are calculated explicitly using full potential-linearized augmented plane wave (FP-LAPW) method. The calculated ground state properties of the investigated compounds agree quite well with the available experimental data. The predicted elastic constants using both PW-PP and FP-LAPW methods are in good accord with each other and show that the materials are mechanically stable. The low values of the elastic moduli indicate that these materials are soft in nature. The bulk properties such as shear moduli, Young's moduli, and Poisson's ratio are derived from the calculated elastic constants. Tran-Blaha modified Becke-Johnson (TB-mBJ) potential improves the band gaps over GGA and Engel-Vosko GGA. The computed TB-mBJ electronic band structure reveals that these materials are direct band gap insulators. The complex dielectric function of the metal oxyhalide compounds have been calculated and the observed prominent peaks are analyzed through the TB-mBJ electronic structures. By using the knowledge of complex dielectric function other important optical properties including absorption, reflectivity, refractive index and loss function have been obtained as a function of energy.

  16. Structural, elastic and magnetic properties of Mn and Sb doped chromium nitride – An ab initio study

    Energy Technology Data Exchange (ETDEWEB)

    Ikram Un Nabi Lone; Sheik Sirajuddeen M Mohamed, E-mail: msheiksiraj@bsauniv.ac.in; Shameem Banu, I.B.; Sathik Basha, S.

    2017-05-01

    Structural, magnetic and elastic properties of Mn and Sb doped CrN were investigated by the electronic band structure calculations using Full Potential Linear Augmented Plane Wave (FP-LAPW) method. The host compound CrN was doped with Mn and Sb separately, in the doping concentration of 12.5% to replace Cr atoms. The introduction of Mn and Sb atoms replacing the Cr atoms does not change the structural stability of the compound. The changes in magnetic and elastic properties were investigated and compared in GGA and GGA+U methods. The doped CrN undergoes a relative increase in the magnetic order with the substitution of Mn and Sb atoms. In GGA method, the magnetic moments are found to be greater in Mn doped CrN than that found in Sb doped Cr{sub 0.875}NSb{sub 0.125}. When doped with Sb, the elastic moduli such as Young’s modulus, bulk modulus and rigidity modulus show a relative increase in comparison with that in Mn doped CrN. Using Hubbard model in GGA+U method, both the magnetic and elastic properties increase in Mn and Sb doped compounds. - Highlights: • Mn and Sb doped Chromium Nitride. • Structural properties. • Magnetic properties. • Elastic properties.

  17. Study of structural, elastic, electronic and thermodynamic properties of NaAlO{sub 3}-perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Bouafia, H. [Laboratoire de Microscope Electronique et Sciences des Materiaux, departement de physique, USTO, BP1505 El m' naouar, Oran (Algeria); Sahli, B. [Laboratoire de Genie Physique, Universite Ibn-Khaldoun, Tiaret 14000 (Algeria); Hiadsi, S. [Laboratoire de Microscope Electronique et Sciences des Materiaux, departement de physique, USTO, BP1505 El m' naouar, Oran (Algeria); Abidri, B., E-mail: b_abidri@hotmail.com [Laboratoire des Materiaux Magnetiques, Universite Djillali Liabes, Sidi Bel-Abbes 22000 (Algeria); Rached, D. [Laboratoire des Materiaux Magnetiques, Universite Djillali Liabes, Sidi Bel-Abbes 22000 (Algeria); Amrani, B. [Departement de Physique, Universite d' Oran es-senia (Algeria)

    2012-06-15

    The structural, elastic, electronic, and thermodynamic properties of the cubic NaAlO{sub 3}-perovskite are calculated using the full potential linearized augmented plane wave with local orbital (FP-LAPW)+lo. The exchange-correlation energy, is treated in generalized gradient approximation (GGA) using the Perdew-Burke-Ernzerhof (PBE) parameterization. The calculated equilibrium parameter is in good agreement with other works. The bulk modulus, elastic constants and their related parameters, such as Young modulus, shear modulus, and Poisson ratio were predicted. The electronic band structure of this compound has been calculated using the Angel-Vosko (EV) generalized gradient approximation (GGA) for the exchange correlation potential. We deduced that NaAlO{sub 3}-perovskite exhibit a wide-gap which it is an indirect from R to {Gamma} point. The analysis of the density of states (DOS) curves shows ionic and covalent character bond for Al-O and Na-O respectively. To complete the fundamental characterization of NaAlO{sub 3} material we have analyzed the thermodynamic properties using the quasi-harmonic Debye model.

  18. Quantifying the Properties of Elastic, Liquid Metal Based Thermal Interface Materials

    Science.gov (United States)

    Kemme, Nicholas

    Advancements in thermal interface materials (TIMs) allows for the creation of new and more powerful electronics as they increase the heat transfer from the component to the heat sink. Current industrial options provide decent heat transfer, but the creation of TIMs with higher thermal conductivities is needed. In addition, if these TIMs are elastic in nature, their effectiveness can greatly increase as they can deal with changing interfaces without degradation of their properties. The research performed delves into this idea, creating elastic TIMs using liquid metal (LM), in this case galinstan, along with other matrix particles embedded in Polydimethylsiloxane (PDMS) to create an easy to use, relatively inexpensive, thermally conductive, but electrically insulative, pad with increased thermal conductivity from industrial solutions. The pads were created using varying amounts of LM and matrix materials ranging from copper microspheres to diamond powder mixed into PDMS using a high-speed mixer. The material was then cast into molds and cured to create the pads. Once the pads were created, the difficulty came in quantifying their thermal properties. A stepped bar apparatus (SBA) following ASTM D5470 was created to measure the thermal resistance of the pads but it was determined that thermal conductivity was a more usable metric of the pads' performance. This meant that the pad's in-situ thickness was needed during testing, prompting the installation of a linear encoder to measure the thickness. The design and analysis of the necessary modification and proposed future design is further detailed in the following paper.

  19. Depressionary Effect of Proximity of Residential Properties to Waste ...

    African Journals Online (AJOL)

    Depressionary Effect of Proximity of Residential Properties to Waste Disposal Sites in Nigeria. ... a helpful Frequently Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link above.

  20. Evaluation of properties of bitumen modified with waste tyre ...

    African Journals Online (AJOL)

    The research investigates the properties of bitumen modified with used tyre. Basic tests such as penetration, softening point, viscosity , flash and fire point and ductility test were carried out by using shredded waste tyre which varied from 0% to 20% by weight of 60/70 penetration grade bitumen at 1600C using dry mix ...

  1. effects of automobile battery wastes on physicochemical properties ...

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    2015-09-28

    Sep 28, 2015 ... battery (Balfour et al., 2011). Wastes from Automobile Battery Manufacturing. Companies (ABMC) are known to release a high percentage of heavy metals like lead (Pb) on soil, the resultant effects also affect the soil physicochemical and its heavy metal properties (Greenpeace 1993; Catwright et al., 1977).

  2. Effects of automobile battery wastes on physicochemical properties ...

    African Journals Online (AJOL)

    Battery wastes were found to be significant sources of Cadmium and Chromium, as none of both was detected in the control soil sample. The daily activities of auto-mechanic battery workshops have negative impacts on soil physicochemical properties. Note, the soil in mechanic battery workshops needs urgent cleanup to ...

  3. Marshall properties of waste polymer and nanoclay modified bitumen

    OpenAIRE

    Sadeque Mohammed; Patil K.A.

    2014-01-01

    Polymer modified bitumen is emerging as one of the important construction materials for flexible pavements. The addition of polymers in bitumen improves the deformational stability and durability of bitumen. Also Montmorillonite nanoclay has been successfully used as additive in polymer to significantly improve the thermal stability and mechanical properties. The present study, the effect of waste low density polyethylene (LDPE), polypropylene (PP) obtained...

  4. Depressionary Effect of Proximity of Residential Properties to Waste ...

    African Journals Online (AJOL)

    It is important to know if and to which extent proximity to waste disposal sites or treatment plants depresses residential property values for many reasons. Whether as a measure of the impact of the sites on health and general welfare of the resident, or to ascertain the degree of monetary depression that would be suffered by ...

  5. Polymer concentration and properties of elastic turbulence in a von Karman swirling flow

    Science.gov (United States)

    Jun, Yonggun; Steinberg, Victor

    2017-10-01

    We report detailed experimental studies of statistical, scaling, and spectral properties of elastic turbulence (ET) in a von Karman swirling flow between rotating and stationary disks of polymer solutions in a wide, from dilute to semidilute entangled, range of polymer concentrations ϕ . The main message of the investigation is that the variation of ϕ just weakly modifies statistical, scaling, and spectral properties of ET in a swirling flow. The qualitative difference between dilute and semidilute unentangled versus semidilute entangled polymer solutions is found in the dependence of the critical Weissenberg number Wic of the elastic instability threshold on ϕ . The control parameter of the problem, the Weissenberg number Wi, is defined as the ratio of the nonlinear elastic stress to dissipation via linear stress relaxation and quantifies the degree of polymer stretching. The power-law scaling of the friction coefficient on Wi/Wic characterizes the ET regime with the exponent independent of ϕ . The torque Γ and pressure p power spectra show power-law decays with well-defined exponents, which has values independent of Wi and ϕ separately at 100 ≤ϕ ≤900 ppm and 1600 ≤ϕ ≤2300 ppm ranges. Another unexpected observation is the presence of two types of the boundary layers, horizontal and vertical, distinguished by their role in the energy pumping and dissipation, which has width dependence on Wi and ϕ differs drastically. In the case of the vertical boundary layer near the driving disk, wvv is independent of Wi/Wic and linearly decreases with ϕ /ϕ * , while in the case of the horizontal boundary layer wvh its width is independent of ϕ /ϕ * , linearly decreases with Wi/Wic , and is about five times smaller than wvv. Moreover, these Wi and ϕ dependencies of the vertical and horizontal boundary layer widths are found in accordance with the inverse turbulent intensity calculated inside the boundary layers Vθh/Vθh rms and Vθv/Vθv rms , respectively

  6. A first principles study of the electronic structure, elastic and thermal properties of UB2

    Science.gov (United States)

    Jossou, Ericmoore; Malakkal, Linu; Szpunar, Barbara; Oladimeji, Dotun; Szpunar, Jerzy A.

    2017-07-01

    Uranium diboride (UB2) has been widely deployed for refractory use and is a proposed material for Accident Tolerant Fuel (ATF) due to its high thermal conductivity. However, the applicability of UB2 towards high temperature usage in a nuclear reactor requires the need to investigate the thermomechanical properties, and recent studies have failed in highlighting applicable properties. In this work, we present an in-depth theoretical outlook of the structural and thermophysical properties of UB2, including but not limited to elastic, electronic and thermal transport properties. These calculations were performed within the framework of Density Functional Theory (DFT) + U approach, using Quantum ESPRESSO (QE) code considering the addition of Coulomb correlations on the uranium atom. The phonon spectra and elastic constant analysis show the dynamic and mechanical stability of UB2 structure respectively. The electronic structure of UB2 was investigated using full potential linear augmented plane waves plus local orbitals method (FP-LAPW+lo) as implemented in WIEN2k code. The absence of a band gap in the total and partial density of states confirms the metallic nature while the valence electron density plot reveals the presence of covalent bond between adjacent B-B atoms. We predicted the lattice thermal conductivity (kL) by solving Boltzmann Transport Equation (BTE) using ShengBTE. The second order harmonic and third-order anharmonic interatomic force constants required as input to ShengBTE was calculated using the Density-functional perturbation theory (DFPT). However, we predicted the electronic thermal conductivity (kel) using Wiedemann-Franz law as implemented in Boltztrap code. We also show that the sound velocity along 'a' and 'c' axes exhibit high anisotropy, which accounts for the anisotropic thermal conductivity of UB2.

  7. Engineering of PHB synthesis causes improved elastic properties of flax fibers.

    Science.gov (United States)

    Wróbel-Kwiatkowska, Magdalena; Zebrowski, Jacek; Starzycki, Michał; Oszmiański, Jan; Szopa, Jan

    2007-01-01

    Flax stem is a source of fiber used by the textile industry. Flax fibers are separated from other parts of stems in the process called retting and are probably the first plant fibers used by man for textile purposes (1). Nowadays flax cultivation is often limited because of its lower elastic property compared to cotton fibers. Thus the goal of this study was to increase the flax fiber quality using a transgenic approach. Expression of three bacterial genes coding for beta-ketothiolase (phb A), acetoacetyl-CoA reductase (phb B), and PHB synthase (phb C) resulted in poly-beta-hydroxybutyrate (PHB) accumulation in the plant stem. PHB is known as a biodegradable thermoplastic displaying chemical and physical properties similar to those of conventional plastics (i.e., polypropylene). The fibers isolated from transgenic flax plants cultivated in the field and synthesizing PHB were then studied for biomechanical properties. All measured parameters, strength, Young's modulus, and energy for failure of flax fibers, were significantly increased. Thus the substantial improvement in elastic properties of fibers from the transgenic line has been achieved. Since the acetyl CoA, substrate for PHB synthesis, is involved not only for energy production but also for synthesis of many cellular constituents, the goal of this study was also the analysis of those metabolites, which interfere with plant physiology and thus fiber quality. The analyzed plants showed that reduction in lignin, pectin, and hemicellulose levels resulted in increased retting efficiency. A significant increase in phenolic acids was also detected, and this was the reason for improved plant resistance to pathogen infection. However, a slight decrease in crop production was detected.

  8. Effect of Concrete Waste Form Properties on Radionuclide Migration

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Skinner, De' Chauna J.; Cordova, Elsa A.; Wood, Marcus I.

    2009-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation) the mechanism of contaminant release, the significance of contaminant release pathways, how waste form performance is affected by the full range of environmental conditions within the disposal facility, the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility, the effect of waste form aging on chemical, physical, and radiological properties and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. Numerous sets of tests were initiated in fiscal years (FY) 2006-2009 to evaluate (1) diffusion of iodine (I) and technetium (Tc) from concrete into uncontaminated soil after 1 and 2 years, (2) I and rhenium (Re) diffusion from contaminated soil into fractured concrete, (3) I and Re (set 1) and Tc (set 2) diffusion from fractured concrete into uncontaminated soil, (4) evaluate the moisture distribution profile within the sediment half-cell, (5) the reactivity and speciation of uranium (VI) (U(VI)) compounds in concrete porewaters, (6) the rate of dissolution of concrete monoliths, and (7) the diffusion of simulated tank waste into concrete.

  9. Combining the AFLOW GIBBS and elastic libraries to efficiently and robustly screen thermomechanical properties of solids

    Science.gov (United States)

    Toher, Cormac; Oses, Corey; Plata, Jose J.; Hicks, David; Rose, Frisco; Levy, Ohad; de Jong, Maarten; Asta, Mark; Fornari, Marco; Buongiorno Nardelli, Marco; Curtarolo, Stefano

    2017-06-01

    Thorough characterization of the thermomechanical properties of materials requires difficult and time-consuming experiments. This severely limits the availability of data and is one of the main obstacles for the development of effective accelerated materials design strategies. The rapid screening of new potential materials requires highly integrated, sophisticated, and robust computational approaches. We tackled the challenge by developing an automated, integrated workflow with robust error-correction within the AFLOW framework which combines the newly developed "Automatic Elasticity Library" with the previously implemented GIBBS method. The first extracts the mechanical properties from automatic self-consistent stress-strain calculations, while the latter employs those mechanical properties to evaluate the thermodynamics within the Debye model. This new thermoelastic workflow is benchmarked against a set of 74 experimentally characterized systems to pinpoint a robust computational methodology for the evaluation of bulk and shear moduli, Poisson ratios, Debye temperatures, Grüneisen parameters, and thermal conductivities of a wide variety of materials. The effect of different choices of equations of state and exchange-correlation functionals is examined and the optimum combination of properties for the Leibfried-Schlömann prediction of thermal conductivity is identified, leading to improved agreement with experimental results than the GIBBS-only approach. The framework has been applied to the AFLOW.org data repositories to compute the thermoelastic properties of over 3500 unique materials. The results are now available online by using an expanded version of the REST-API described in the Appendix.

  10. Effects of alloying elements and temperature on the elastic properties of W-based alloys by first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yong-Jie, E-mail: yoh5120@psu.edu [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Shang, Shun-Li; Wang, Yi [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Darling, Kristopher A.; Butler, Brady G.; Kecskes, Laszlo J. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, RDRL-WMM-F, Aberdeen Proving Ground, MD 21005 (United States); Liu, Zi-Kui [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States)

    2016-06-25

    The influence of various transition alloying elements (X's) on the elastic properties of W-based alloys has been studied via first-principles calculations on the basis of density functional theory. Here, nineteen transition metal alloying elements (X) are considered: Ti, V, Cr, Fe, Co, Ni, Y, Zr, Nb, Mo, Ru, Rh, Pd, Hf, Ta, Re, Os, Ir, and Pt. It is found that (i) the bulk modulus of the dilute W-X alloy decreases with increasing its equilibrium volume, particularly, for the alloying elements in the same period; (ii) all of the alloying elements decrease the shear modulus of BCC W; and (iii) the largest decrease of elastic properties of W is due to alloying element Y. In addition, it is shown that the changes of elastic properties of W caused by the alloying elements are traceable from the electron charge density distribution, resulting in a bonding distortion between W and the alloying atoms. Using the quasi-static approach based on the Debye model, the elastic properties of these W-X alloys at finite temperatures are predicted. Calculated properties of BCC W and the W-X alloys are in favorable agreement with available experimental measurements. - Highlights: • The effects of nineteen metal elements on the elastic properties of W are studied. • The elastic properties at finite temperatures are predicted by the Debye model. • The alloying effects can be traceable from the changes of electronic structure. • The possibly promising alloying elements to soften BCC W are suggested.

  11. Electronic, magnetic, elastic and thermodynamic properties of Cu{sub 2}MnGa

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sukriti [Department of Physics, Government Kamla Raja Girls Autonomous Post Graduate College, Gwalior 474001, Madhya Pradesh (India); Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior 474 011, Madhya Pradesh (India); Gupta, Dinesh C., E-mail: sosfizix@gmail.com [Condensed Matter Theory Group, School of Studies in Physics, Jiwaji University, Gwalior 474 011, Madhya Pradesh (India)

    2016-08-01

    The full-potential linearized augmented plane wave method in the stable Fm-3m phase has been implemented to investigate the structural, elastic, magnetic and electronic properties of Cu{sub 2}MnGa. The optimized equilibrium lattice parameter in stable phase is found to be 5.9495 Å. By the spin resolved density of states calculations, we have shown that the exchange splitting due to Mn atom is the main reason of ferromagnetic behavior of Cu{sub 2}MnGa. The absence of energy gap in both the spin channels predicts that the material is metallic. The total and partial density of states, elastic constants, Shear, Bulk and Young’s moduli, Zener isotropy factor, Cauchy pressure, Pugh's ductility, Kleinman parameter and Poisson's ratio are reported for the first time for the alloy. Cauchy's pressure and Pugh's index of ductility label Cu{sub 2}MnGa as ductile. Cu{sub 2}MnGa is found to be ferromagnetic and anisotropic in nature. The quasi-harmonic approximations have been employed to study the pressure and temperature dependent thermodynamic properties of Cu{sub 2}MnGa. - Highlights: • It is the first attempt to predict a variety of crystal properties of Cu{sub 2}MnGa. • Cu{sub 2}MnGa shows magnetism and hence can prove to be important in modern technology. • Cu{sub 2}MnGa is ductile and hence can attract attention of scientists and technologists.

  12. Characterization and assessment of hyperelastic and elastic properties of decellularized human adipose tissues.

    Science.gov (United States)

    Omidi, Ehsan; Fuetterer, Lydia; Reza Mousavi, Seyed; Armstrong, Ryan C; Flynn, Lauren E; Samani, Abbas

    2014-11-28

    Decellularized adipose tissue (DAT) has shown potential as a regenerative scaffold for plastic and reconstructive surgery to augment or replace damaged or missing adipose tissue (e.g. following lumpectomy or mastectomy). The mechanical properties of soft tissue substitutes are of paramount importance in restoring the natural shape and appearance of the affected tissues, and mechanical mismatching can lead to unpredictable scar tissue formation and poor implant integration. The goal of this work was to assess the linear elastic and hyperelastic properties of decellularized human adipose tissue and compare them to those of normal breast adipose tissue. To assess the influence of the adipose depot source on the mechanical properties of the resultant decellularized scaffolds, we performed indentation tests on DAT samples sourced from adipose tissue isolated from the breast, subcutaneous abdominal region, omentum, pericardial depot and thymic remnant, and their corresponding force-displacement data were acquired. Elastic and hyperelastic parameters were estimated using inverse finite element algorithms. Subsequently, a simulation was conducted in which the estimated hyperelastic parameters were tested in a real human breast model under gravity loading in order to assess the suitability of the scaffolds for implantation. Results of these tests showed that in the human breast, the DAT would show similar deformability to that of native normal tissue. Using the measured hyperelastic parameters, we were able to assess whether DAT derived from different depots exhibited different intrinsic nonlinearities. Results showed that DAT sourced from varying regions of the body exhibited little intrinsic nonlinearity, with no statistically significant differences between the groups. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Pressure effects on the elastic and lattice dynamics properties of AlP from first-principles calculations

    Science.gov (United States)

    Lakel, S.; Okbi, F.; Ibrir, M.; Almi, K.

    2015-03-01

    We have performed first-principles calculations to investigate the behavior under hydrostatic pressure of the structural, elastic and lattice dynamics properties of aluminum phosphide crystal (AlP), in both zinc-blende (B3) and nickel arsenide (B8) phases. Our calculated structural and electronic properties are in good agreement with previous theoretical and experimental results. The elastic constants, bulk modulus (B), shear modulus (G), and Young's modulus (E), Born effective charge and static dielectric constant ɛ0, were calculated with the generalized gradient approximations and the density functional perturbation theory (DFPT). Our results in the pressure behavior of the elastic and dielectric properties of both phases are compared and contrasted with the common III-V materials. The Born effective charge ZB decreases linearly with pressure increasing, while the static dielectric constant decreases quadratically with the increase of pressure.

  14. First principles study on structural, electronic, elastic and thermal properties of equiatomic CoTi and CoZr

    Science.gov (United States)

    Acharya, Nikita; Fatima, Bushra; Chouhan, Sunil Singh; Sanyal, Sankar P.

    2013-06-01

    We have investigated the structural, electronic, elastic and thermal properties of CoTi and CoZr using ab-initio full potential linearized plane wave method (FP-LAPW) method within generalized gradient approximation (GGA). The calculated the ground state and electronic properties such as lattice constant (a0), bulk modulus (B0), its pressure derivative (B0') and density of states at Fermi level N (EF) which are in good agreement with other experimental and theoretical results. The elastic constants (C11, C12 and C44) are also calculated for these compounds. Ductility has been analyzed by Pugh's rule (B/GH) ratio and Cauchy's pressure (C12-C44). To the best of our knowledge, the elastic and thermal properties of CoZr are calculated first time.

  15. Comparison of mechanical properties of glass-bonded sodalite and borosilicate glass high-level waste forms

    Energy Technology Data Exchange (ETDEWEB)

    O' Holleran, T. P.; DiSanto, T.; Johnson, S. G.; Goff, K. M.

    2000-05-09

    Argonne National Laboratory has developed a glass-bonded sodalite waste form to immobilize the salt waste stream from electrometallurgical treatment of spent nuclear fuel. The waste form consists of 75 vol.% crystalline sodalite and 25 vol.% glass. Microindentation fracture toughness measurements were performed on this material and borosilicate glass from the Defense Waste Processing Facility using a Vickers indenter. Palmqvist cracking was confined for the glass-bonded sodalite waste form, while median-radial cracking occurred in the borosilicate glass. The elastic modulus was measured by an acoustic technique. Fracture toughness, microhardness, and elastic modulus values are reported for both waste forms.

  16. Ultrasonic measurement of the elastic properties of ultra-high performance concrete (UHPC)

    Science.gov (United States)

    Washer, Glenn; Fuchs, Paul; Rezai, Ali; Ghasemi, Hamid

    2005-05-01

    This paper discusses research to develop ultrasonic methods for materials characterization of an innovative new material known as Reactive Powder Concrete (RPC). Also known as Ultra-high performance concrete (UHPC), this relatively new material has been proposed for the construction of civil structures. UHPC mix designs typically include no aggregates larger than sand, and include steel fibers 0.2 mm in diameter and 12 mm in length. These steel fibers increase the strength and toughness of the UHPC significantly relative to more traditional concretes. Compressive strengths of 200 to 800 MPa have been achieved with UHPC, compared with maximum compressive strength of 50 to 100 MPa for more traditional concrete materials. Young"s modulus of 50 to 60 GPa are common for UHPC. However, the curing methods employed have a significant influence on the strength and modulus of UHPC. This paper reports on the development of ultrasonic methods for monitoring the elastic properties of UHPC under a series of curing scenarios. Ultrasonic velocity measurements are used to estimate the bulk elastic modulus of UHPC and results are compared with traditional, destructive methods. Measurements of shear moduli and Poisson's ratio based on ultrasonic velocity are also reported. The potential for the development of quality control techniques for the future implementation of UHPC is discussed.

  17. Effect of nanostructuring on the elastic properties of aluminum alloy AMg6

    Energy Technology Data Exchange (ETDEWEB)

    Prokhorov, V., E-mail: pvm@tisnum.ru; Perfilov, S. [Technological Institute for Superhard and Novel Carbon Materials. Centralnaya 7a, Moscow, Troitsk, 142190 (Russian Federation); Korobov, A., E-mail: aikor42@mail.ru; Kokshaiskii, A.; Volkov, A. [Department of Acoustics, Faculty of Physics, M.V. Lomonosov Moscow State University. Leninskie gory 1, Moscow, 119991 (Russian Federation)

    2015-10-28

    We experimentally investigated the nanostructuring effect on the elastic properties of aluminum alloy AMg6 (Al–Mg–Mn system). The n-AMg6 nanostuctured specimens were prepared from a commercial polycrystalline alloy by refining and homogenizing a mixture of small chips of the alloy in a planetary mill. The resulting product consists of 200-500-micron agglomerates of nanoparticles with average nanoparticle size ∼ 40–60 nanometer according to the X-ray analysis. The compacted nanopowder was extruded at a temperature of 300°C with a reduction of cross-sectional area at least 4 times to 90 mm diameter. High resolution transmission electron microscopy studies confirmed the presence of the nanostructure with a grain size of ∼60 nanometers. For the experiments, nine parallelepiped shape specimens of 20×20×40 mm{sup 3} size were cut from the central and peripheral parts of the n-AMg6 rod. We measured of the second-order and third-order elastic coefficients of the obtained samples by ultrasonic method. The same measurements were made on specimens of the primary AMg6 alloy for comparison.

  18. Micromechanical modeling of elastic properties of cortical bone accounting for anisotropy of dense tissue.

    Science.gov (United States)

    Salguero, Laura; Saadat, Fatemeh; Sevostianov, Igor

    2014-10-17

    The paper analyzes the connection between microstructure of the osteonal cortical bone and its overall elastic properties. The existing models either neglect anisotropy of the dense tissue or simplify cortical bone microstructure (accounting for Haversian canals only). These simplifications (related mostly to insufficient mathematical apparatus) complicate quantitative analysis of the effect of microstructural changes - produced by age, microgravity, or some diseases - on the overall mechanical performance of cortical bone. The present analysis fills this gap; it accounts for anisotropy of the dense tissue and uses realistic model of the porous microstructure. The approach is based on recent results of Sevostianov et al. (2005) and Saadat et al. (2012) on inhomogeneities in a transversely-isotropic material. Bone's microstructure is modeled according to books of Martin and Burr (1989), Currey (2002), and Fung (1993) and includes four main families of pores. The calculated elastic constants for porous cortical bone are in agreement with available experimental data. The influence of each of the pore types on the overall moduli is examined. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Elastic properties of muscle-tendon complex in long-distance runners.

    Science.gov (United States)

    Kubo, K; Kanehisa, H; Kawakami, Y; Fukunaga, T

    2000-02-01

    The purpose of this study was to investigate the elastic properties of muscle-tendon complex (MTC) in knee extensor muscles and the capacity for elastic energy utilization in long-distance runners (LDR) by comparing with data obtained from untrained individuals (CON). The elongation (L) of the tendon and aponeurosis of vastus lateralis muscle during isometric knee extension was determined by real-time brightness mode ultrasonography, while the subjects developed a gradually increasing torque from 0 (relaxed) to maximal effort (MVC) within 7 s. In addition, performances in two kinds of maximal vertical jumps, i.e. squatting (SJ) and counter-movement jumps (CMJ), were measured. The relationship between L muscle and force (F) was curvilinear and consisted of an initial region (toe region), characterized by a large increase in L with increasing F, immediately followed by a linear region. The slope of the regression equation for the L-F relationship in the range 50%-100% of MVC was defined as an index of MTC compliance, where the rate of the changes in L to that in muscle F at every 10% of MVC became almost constant. The maximal L (Lmax) and MTC compliance were significantly lower in LDR than in CON: 29.9 (SD 3.9) mm in LDR compared to 33.3 (SD 5.5) mm in CON for Lmax and 1.55 (SD 0.25) x 10(-2) mm.N-1 in LDR compared to 1.88 (SD 0.82) x 10(-2) mm.N-1 in CON for MTC compliance. Also, LDR showed significantly less elastic energy absorption (Ee) than CON, defined as the area below the L-F relationship curve from 0 to 100% of MVC. Not only jump heights but also the differences between the heights in SJ and CMJ, expressed as the percentage of the height in SJ, were significantly lower in LDR than in CON. The augmentation with counter-movement was significantly correlated to either MTC compliance (r = 0.554, P untrained individuals. These elastic profiles of vastus lateralis muscle in LDR may be associated with their lower performances during CMJ.

  20. Characterization of passive elastic properties of the human medial gastrocnemius muscle belly using supersonic shear imaging.

    Science.gov (United States)

    Maïsetti, Olivier; Hug, François; Bouillard, Killian; Nordez, Antoine

    2012-04-05

    The passive elastic properties of a muscle-tendon complex are usually estimated from the relationship between the joint angle and the passive resistive torque, although the properties of the different structures crossing the joint cannot be easily assessed. This study aimed to determine the passive mechanical properties of the gastrocnemius medialis muscle (GM) using supersonic shear imaging (SSI) that allows the measurement of localized muscle shear modulus (μ). The SSI of the GM was taken for 7 subjects during passive ankle dorsiflexion at a range of knee positions performed on an isokinetic dynamometer. The relationship between normalized μ and the length of the gastrocnemius muscle-tendon units (GMTU) was very well fitted to an exponential model (0.944knee fully extended was calculated. The μ-length relationship was highly correlated with the force-length (0.964knee extended were similar to that reconstructed from all knee angles and displayed good intra-session reliability (for α, SEM: 9.7 m(-1); CV: 7.5%; ICC: 0.652; for l(0), SEM: 0.002 m; CV: 0.4%; ICC: 0.992). These findings indicate that SSI may provide an indirect estimation of passive muscle force, and highlight its clinical applicability to evaluate the passive properties of mono- and bi-articular muscles. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Elastic and transport properties of cellular solids derived from three-dimensional tomographic images

    Science.gov (United States)

    Knackstedt, Mark A.; Arns, Christoph H.; Saadatfar, Mohammad; et al.

    2006-09-01

    We describe a three-dimensional imaging and analysis study of eight industrial cellular foam morphologies. The foam morphologies were generated by differing industrial processing methods. Tomograms are acquired on an X-ray micro-computed tomography facility at scales of approximately equal to (5mm)3 at resolutions down to 7μm. The image quality is sufficient in all cases to measure local structure and connectivity of the foamed material, and the field of view large enough to calculate a range of material properties. Phase separation into solid and porous components is straightforward.Three-dimensional structural characteristics are measured directly on the porous and solid phases of the images. A number of morphological parameters are obtained, including pore volume-to-surface-area ratio, connectivity, the pore and solid phase size distributions defined by maximal sphere openings and chord length measurements. We further calculate the pore size distribution associated with capillary pressure via simulating of mercury drainage on the digital images.The binarized microstructures are used as a basis for calculations of transport properties (fluid permeability, diffusivity and thermal conductivity) and elastic moduli. From the data, we generate property-porosity relationships for the range of foam morphologies imaged and quantitatively analyse the effects of porosity and microstructure on the resultant properties of the foams.We compare our numerical data to commonly used theoretical and empirical property-porosity relationships. For thermal conductivity, we find that the numerical results agree extremely well with an empirical expression based on experimental data of various foams. The upper Hashin-Shtrikman bound also provides an excellent prediction of the data across all densities. From simulation of the diffusivity, we can define the tortuosity of the pore space within the cellular solid. We find that different processing methods lead to strong variations in the

  2. Removal properties of low-thermal-expansion materials with rotating-sphere elastic emission machining

    Directory of Open Access Journals (Sweden)

    Masahiko Kanaoka et al

    2007-01-01

    Full Text Available Optical mirrors used in extreme ultraviolet lithography systems require a figure accuracy and a roughness of about 0.1 nm rms. In addition, mirror substrates must be low-thermal-expansion materials. Thus, in this study, we processed two low-thermal-expansion materials, ULE [K. Hrdina, B. Hanson, P. Fenn, R. Sabia, Proc. SPIE 4688 (2002 454.] (Corning Inc. and Zerodur [I. Mitra, M.J. Davis, J. Alkemper, Rolf Müller, H. Kohlmann, L. Aschke, E. Mörsen, S. Ritter, H. Hack, W. Pannhorst, Proc. SPIE 4688 (2002 462.] (SCHOTT AG, with elastic emission machining (EEM in order to evaluate the removal properties. Consequently, we successfully calculated the respective removal rates, because removal volumes were found to be proportional to process times in EEM. Moreover, we demonstrated that the surface roughness of Zerodur is reduced to 0.1 nm rms in the spatial wavelength range from 100 μm to 1 mm.

  3. Calculated Changes in the Elastic Properties of MgCNi3 at the Superconducting Transition

    Directory of Open Access Journals (Sweden)

    R. Abd-Shukor

    2013-01-01

    Full Text Available We calculated the elastic properties of MgCNi3 at the superconducting transition ( using various thermodynamic and acoustic data. From the calculations, a step discontinuity of 8 ppm in the bulk modulus, 7 ppm in the Young’s modulus, and 3 ppm in the longitudinal sound velocity ( is expected at . The step discontinuities at the transition temperature indicated the importance of lattice changes to the superconducting mechanism of MgCNi3. The Debye temperature was calculated to be 460 K. The electron-phonon coupling constants calculated in the weak and strong coupling limits of the BCS theory and the van Hove scenario showed that MgCNi3 is a moderately strong coupled superconductor.

  4. Elastic stability and optical property under pressure of TiN phases: by first principles study

    Science.gov (United States)

    Eslam, Farzaneh Ghafari; Boochani, Arash; Babaeipour, Manuchehr; Khodadadi, Jabbar

    2017-11-01

    The electronic and optical properties of the rock-salt, CsCl-type, zinc-blende and wurtzite phases of TiN have been calculated by First-Principles study for relaxed and under pressure conditions. Calculations are based on the density functional theory and full potential augmented plane waves method by Generalized Gradient Approximation. The optical transitions in zero pressure are derived from the density of states and dielectric function. In addition, various optical characters, such as reflectivity, refraction and extinction indices, under positive and negative pressures are compared and contrasted. It is found that all mentioned phases of TiN are elastically stable and exhibit a rising trend in their plasmonic frequencies by increasing the pressure imposed on.

  5. First principle electronic, structural, elastic, and optical properties of strontium titanate

    Directory of Open Access Journals (Sweden)

    Chinedu E. Ekuma

    2012-03-01

    Full Text Available We report self-consistent ab-initio electronic, structural, elastic, and optical properties of cubic SrTiO3 perovskite. Our non-relativistic calculations employed a generalized gradient approximation (GGA potential and the linear combination of atomic orbitals (LCAO formalism. The distinctive feature of our computations stem from solving self-consistently the system of equations describing the GGA, using the Bagayoko-Zhao-Williams (BZW method. Our results are in agreement with experimental ones where the later are available. In particular, our theoretical, indirect band gap of 3.24 eV, at the experimental lattice constant of 3.91 Å, is in excellent agreement with experiment. Our predicted, equilibrium lattice constant is 3.92 Å, with a corresponding indirect band gap of 3.21 eV and bulk modulus of 183 GPa.

  6. Thermal stresses in a spherical pressure vessel having temperature-dependent, transversely isotropic, elastic properties

    Science.gov (United States)

    Tauchert, T. R.

    1976-01-01

    Rayleigh-Ritz and modified Rayleigh-Ritz procedures are used to construct approximate solutions for the response of a thick-walled sphere to uniform pressure loads and an arbitrary radial temperature distribution. The thermoelastic properties of the sphere are assumed to be transversely isotropic and nonhomogeneous; variations in the elastic stiffness and thermal expansion coefficients are taken to be an arbitrary function of the radial coordinate and temperature. Numerical examples are presented which illustrate the effect of the temperature-dependence upon the thermal stress field. A comparison of the approximate solutions with a finite element analysis indicates that Ritz methods offer a simple, efficient, and relatively accurate approach to the problem.

  7. Uncovering New Thermal and Elastic Properties of Nanostructured Materials Using Coherent EUV Light

    Science.gov (United States)

    Hernandez Charpak, Jorge Nicolas

    Advances in nanofabrication have pushed the characteristic dimensions of nanosystems well below 100nm, where physical properties are often significantly different from their bulk counterparts, and accurate models are lacking. Critical technologies such as thermoelectrics for energy harvesting, nanoparticle-mediated thermal therapy, nano-enhanced photovoltaics, and efficient thermal management in integrated circuits depend on our increased understanding of the nanoscale. However, traditional microscopic characterization tools face fundamental limits at the nanoscale. Theoretical efforts to build a fundamental picture of nanoscale thermal dynamics lack experimental validation and still struggle to account for newly reported behaviors. Moreover, precise characterization of the elastic behavior of nanostructured systems is needed for understanding the unique physics that become apparent in small-scale systems, such as thickness-dependent or fabrication-dependent elastic properties. In essence, our ability to fabricate nanosystems has outstripped our ability to understand and characterize them. In my PhD thesis, I present the development and refinement of coherent extreme ultraviolet (EUV) nanometrology, a novel tool used to probe material properties at the intrinsic time- and length-scales of nanoscale dynamics. By extending ultrafast photoacoustic and thermal metrology techniques to very short probing wavelengths using tabletop coherent EUV beams from high-harmonic upconversion (HHG) of femtosecond lasers, coherent EUV nanometrology allows for a new window into nanoscale physics, previously unavailable with traditional techniques. Using this technique, I was able to probe both thermal and acoustic dynamics in nanostructured systems with characteristic dimensions below 50nm with high temporal (sub-ps) and spatial (work is needed for a full theoretical quantitative picture of the experimental results. In other work, I used coherent EUV nanometrology to simultaneously

  8. Mapping Elastic Properties of Heterogeneous Materials in Liquid with Angstrom-Scale Resolution.

    Science.gov (United States)

    Amo, Carlos A; Perrino, Alma P; Payam, Amir F; Garcia, Ricardo

    2017-09-26

    Fast quantitative mapping of mechanical properties with nanoscale spatial resolution represents one of the major goals of force microscopy. This goal becomes more challenging when the characterization needs to be accomplished with subnanometer resolution in a native environment that involves liquid solutions. Here we demonstrate that bimodal atomic force microscopy enables the accurate measurement of the elastic modulus of surfaces in liquid with a spatial resolution of 3 Å. The Young's modulus can be determined with a relative error below 5% over a 5 orders of magnitude range (1 MPa to 100 GPa). This range includes a large variety of materials from proteins to metal-organic frameworks. Numerical simulations validate the accuracy of the method. About 30 s is needed for a Young's modulus map with subnanometer spatial resolution.

  9. An examination of the elastic properties of tissue-mimicking phantoms using vibro-acoustography and a muscle motor system

    Science.gov (United States)

    Maccabi, A.; Taylor, Z.; Bajwa, N.; Mallen-St. Clair, J.; St. John, M.; Sung, S.; Grundfest, W.; Saddik, G.

    2016-02-01

    Tissue hardness, often quantified in terms of elasticity, is an important differentiating criterion for pathological identity and is extensively used by surgeons for tumor localization. Delineation of malignant regions from benign regions is typically performed by visual inspection and palpation. Although practical, this method is highly subjective and does not provide quantitative metrics. We have previously reported on Vibro-Acoustography (VA) for tumor delineation. VA is unique in that it uses the specific, non-linear properties of tumor tissue in response to an amplitude modulated ultrasound beam to generate spatially resolved, high contrast maps of tissue. Although the lateral and axial resolutions (sub-millimeter and sub-centimeter, respectively) of VA have been extensively characterized, the relationship between static stiffness assessment (palpation) and dynamic stiffness characterization (VA) has not been explicitly established. Here we perform a correlative exploration of the static and dynamic properties of tissue-mimicking phantoms, specifically elasticity, using VA and a muscle motor system. Muscle motor systems, commonly used to probe the mechanical properties of materials, provide absolute, quantitative point measurements of the elastic modulus, analogous to Young's modulus, of a target. For phantoms of varying percent-by-weight concentrations, parallel VA and muscle motor studies conducted on 18 phantoms reveal a negative correlation (p elastic modulus values from force vs. indentation depth curves. Comparison of these elasticity measurements may provide additional information to improve tissue modeling, system characterization, as well as offer valuable insights for in vivo applications, specifically surgical extirpation of tumors.

  10. Computational study of structural, elastic and electronic properties of lithium disilicate (Li(2)Si(2)O(5)) glass-ceramic.

    Science.gov (United States)

    Biskri, Zine Elabidine; Rached, Habib; Bouchear, Merzoug; Rached, Djamel

    2014-04-01

    The objective of this study is to investigate theoretically the structural, elastic and electronic properties of Lithium Disilicate (LD) crystal (Li2Si2O5), using the pseudo potential method based on Density Functional Theory (DFT) with the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA). The calculated structural properties namely the equilibrium lattice parameters and cell volume are in good agreement with the available experimental results. However, for the LD crystal elastic moduli: Shear modulus G, Young's modulus E and Poisson's ratio ν we have found a discrepancy between our theoretical values and experimental ones reported in polycrystalline sample containing LD crystals. The calculated elastic properties show that LD is more rigid compared with other components. We also investigated the mechanical stability of Li2Si2O5 compound and we have noticed that this compound is stable against elastic deformations. On the basis of shear to bulk modulus ratio analysis, we inferred that Li2Si2O5 compound is brittle in nature. In order to complete the fundamental characteristics of this compound we have measured the elastic anisotropy. Our results for the energy band structure and Density of States (DOS) show that Li2Si2O5 compound has an insulator characteristic. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Elastic properties of the aorta and factors affecting aortic stiffness in patients with

    Directory of Open Access Journals (Sweden)

    Derya Tok

    2012-09-01

    Full Text Available Objectives: In this study, we evaluated aortic stiffnessand echocardiographic and laboratory factors affectingaortic stiffness in patients with metabolic syndrome(MetS.Materials and methods: Forty-six patients (25 male,mean age 47.3±6.5 years with the diagnosis of MetS accordingto the Adult Treatment Panel III Final Report criteriawere included. Forty-four age and gender matchedhealthy subjects (18 male, mean age 46.0±6.1 yearswere recruited as the control group. Aortic strain, distensibilityand stiffness index were calculated by M-modeechocardiography and diastolic parameters were measured.Results: Left ventricular mass index (LVMI, decelerationtime (DT, isovolumic relaxation time (IVRT wereincreased and mitral E/A ratio was decreased in patientswith MetS compared to controls. In the MetS patients,aortic distensibility was significantly decreased (10.4±3.5cm2.dyn-1.10-6 vs. 12.7±3.4 cm2.dyn-1.10-6, p=0.002,and ASI was significantly increased (6.5±2.0 vs. 3.2±0.8,p<0.001. ASI was positively correlated with triglycerides,fasting glucose, uric acid, hsCRP, LVMI, DT, IVRT andsystolic blood pressure level, and was negatively correlatedwith HDL-cholesterol and mitral E/A ratio. In regressionanalysis, hsCRP (p=0.05 and systolic blood pressurelevel (p<0.001 were independent predictors of ASI.Conclusions: ASI is increased in patients with MetS. Inthese patients; decrease in aortic elasticity properties wasassociated with left ventricular diastolic dysfunction. Highsystolic pressure and hsCRP levels were found to be independentpredictors of ASI.Key words: Metabolic syndrome, Echocardiography,elastic properties of aorta, hsCRP

  12. Quantifying the Elastic Property of Nine Thigh Muscles Using Magnetic Resonance Elastography.

    Science.gov (United States)

    Chakouch, Mashhour K; Charleux, Fabrice; Bensamoun, Sabine F

    2015-01-01

    Pathologies of the muscles can manifest different physiological and functional changes. To adapt treatment, it is necessary to characterize the elastic property (shear modulus) of single muscles. Previous studies have used magnetic resonance elastography (MRE), a technique based on MRI technology, to analyze the mechanical behavior of healthy and pathological muscles. The purpose of this study was to develop protocols using MRE to determine the shear modulus of nine thigh muscles at rest. Twenty-nine healthy volunteers (mean age = 26 ± 3.41 years) with no muscle abnormalities underwent MRE tests (1.5 T MRI). Five MRE protocols were developed to quantify the shear moduli of the nine following thigh muscles at rest: rectus femoris (RF), vastus medialis (VM), vastus intermedius (VI), vastus lateralis (VL), sartorius (Sr), gracilis (Gr), semimembranosus (SM), semitendinosus (ST), and biceps (BC). In addition, the shear modulus of the subcutaneous adipose tissue was analyzed. The gracilis, sartorius, and semitendinosus muscles revealed a significantly higher shear modulus (μ_Gr = 6.15 ± 0.45 kPa, μ_ Sr = 5.15 ± 0.19 kPa, and μ_ ST = 5.32 ± 0.10 kPa, respectively) compared to other tissues (from μ_ RF = 3.91 ± 0.16 kPa to μ_VI = 4.23 ± 0.25 kPa). Subcutaneous adipose tissue had the lowest value (μ_adipose tissue = 3.04 ± 0.12 kPa) of all the tissues tested. The different elasticities measured between the tissues may be due to variations in the muscles' physiological and architectural compositions. Thus, the present protocol could be applied to injured muscles to identify their behavior of elastic property. Previous studies on muscle pathology found that quantification of the shear modulus could be used as a clinical protocol to identify pathological muscles and to follow-up effects of treatments and therapies. These data could also be used for modelling purposes.

  13. Elastic and electronic properties of antiperovskite-type Pd- and Pt-based ternary carbides from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, V.V.; Ivanovskii, A.L., E-mail: ivanovskii@ihim.uran.ru

    2013-11-15

    Highlights: • 23 Pd- and Pt-based antiperovskite-type ternary carbides are probed from first principles. • Structural, elastic, electronic properties and inter-atomic bonding are evaluated. • A rich variety of mechanical and electronic properties was predicted. -- Abstract: By means of first-principles calculations, the structural, elastic, and electronic properties of a broad series of proposed Pd- and Pt-based antiperovskite-type ternary carbides AC(Pd,Pt){sub 3}, where A are Zn, Ca, Al, Ga, In, Ge, Hg, Sn, Cd, Pb, Ag, Sc, Ti, Y, Nb, Mo, and Ta, have been studied, and their stability, elastic constants, bulk, shear, and Young’s moduli, compressibility, Pugh’s indicator, Poisson’s ratio, indexes of elastic anisotropy, as well as electronic properties have been evaluated. We found that these materials should demonstrate a rich variety of mechanical and electronic properties depending on the type of A sublattices, which can include (unlike the majority of known 3d-metal-based antiperovskites) both sp elements and d atoms. We believe that the presented results will be useful for future synthesis of these phases, as well as for expanding our knowledge of this interesting group of antiperovskite-type materials.

  14. LEATHER WASTE VALORISATION THROUGH MATERIAL INNOVATION: SOME PROPERTIES OF LEATHER WOOD FIBREBOARD

    Directory of Open Access Journals (Sweden)

    Axel M. RINDLER

    2015-12-01

    Full Text Available Due to the ever-increasing scarcity of resources and raw materials in the wood panels industry, it is imperative to look for suitable alternatives to the established resources. Therefore a combination of the traditionally used and newly explored sources may reveal highly innovative ways. The objective of this study is to provide an insight into the behavior of the material and possible new applications of those fiber/particle wood and waste leather composites. For this reason exclusively fibers of spruce were used for the trials. Wet white (WW leather particles and wet blue (WB leather particles were mixed with the wooden materials for the production of high density fibreboards. Besides the mechanical properties such as the internal bond (IB the bending strength (MOR and modulus of elasticity (MOE was analyzed. Further physical property as thickness swelling after 24h watering was investigated. To analyze how the density influences the behavior under thermal conditions, fiberboards with the densities 500, 700 and 900 kg/m³ were tested. The results of the material properties were influenced by the leather content of the panels. The results for the UF-bonded HDF boards show enhancement of the transverse IB with increasing wet blue leather content, whereas the other mechanical properties decline meanwhile. The thickness swelling showed higher values compared to the wood fibreboard. The results of this study underline the usefulness of integrating leather shavings to HDF and give an overview of their influence in wood fiber materials. The combination of the natural resource wood fiber and the leather waste products (Wet Blue and Wet White gives a very interesting new material, its mechanical properties allow a variety of possible application in future applications.

  15. Parallel calculations of vibrational properties in complex materials: negative thermal expansion and elastic inhomogeneity

    Science.gov (United States)

    Vila, F. D.; Rehr, J. J.

    Effects of thermal vibrations are essential to obtain a more complete understanding of the properties of complex materials. For example, they are important in the analysis and simulation of x-ray absorption spectra (XAS). In previous work we introduced an ab initio approach for a variety of vibrational effects, such as crystallographic and XAS Debye-Waller factors, Debye and Einstein temperatures, and thermal expansion coefficients. This approach uses theoretical dynamical matrices from which the locally-projected vibrational densities of states are obtained using a Lanczos recursion algorithm. In this talk I present recent improvements to our implementation, which permit simulations of more complex materials with up to two orders of magnitude larger simulation cells. The method takes advantage of parallelization in calculations of the dynamical matrix with VASP. To illustrate these capabilities we discuss two problems of considerable interest: negative thermal expansion in ZrW2O8; and local inhomogeneities in the elastic properties of supported metal nanoparticles. Both cases highlight the importance of a local treatment of vibrational properties. Supported by DOE Grant DE-FG02-03ER15476, with computer support from DOE-NERSC.

  16. Elasticity, biodegradability and cell adhesive properties of chitosan/hyaluronan multilayer films

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Aurore; Richert, Ludovic; Francius, Gregory; Voegel, Jean-Claude; Picart, Catherine [Present address: Universite de Montpellier II, CNRS-UMR 5539, cc107, Place Eugene Bataillon, 34 095 Montpellier Cedex 5 (France)

    2007-03-01

    In the bioengineering field, a recent and promising approach to modifying biomaterial surfaces is the layer-by-layer (LbL) technique used to build thin polyelectrolyte multilayer films. In this work, we focused on polyelectrolyte multilayer films made of two polysaccharides, chitosan (CHI) and hyaluronan (HA), and on the control of their physico-chemical and cell adhesive properties by chemical cross-linking. CHI/HA films were cross-linked using a water soluble carbodiimide and observed by confocal laser scanning microscopy (CLSM) with a fluorescently labeled CHI. Film thicknesses were similar for native and cross-linked films. The film nanometer roughness was measured by atomic force microscopy and was found to be higher for cross-linked films. Cross-linking the films also leads to a drastic change in film stiffness. The elastic modulus of the films (Young's modulus) as measured by AFM nano-indentation was about tenfold increased for cross-linked films as compared to native ones. From a biological point of view, cross-liked films are more resistant to enzymatic degradation by hyaluronidase. Furthermore, the increase in film stiffness has a favorable effect on the adhesion and spreading of chondrosarcoma cells. Thus, the CHI/HA cross-linked films could be used for various applications due to their adhesive properties and to their mechanical properties (including stability in enzymatic media)

  17. Magnetic, elastic and optical properties of zinc peroxide (ZnO{sub 2}): First principles study

    Energy Technology Data Exchange (ETDEWEB)

    Thapa, Ranjit, E-mail: ranjit.t@res.srmuniv.ac.in [SRM Research Institute, SRM University, Kattankulathur 603 203, Tamil Nadu (India); Ghosh, Saurabh, E-mail: sg827@cornell.edu [School of Applied and Engineering Physics, Cornell University, Ithaca, NY (United States); Sinthika, S.; Mathan Kumar, E. [SRM Research Institute, SRM University, Kattankulathur 603 203, Tamil Nadu (India); Park, Noejung [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of)

    2015-01-25

    Highlights: • XO{sub 2}{sup 2−} materials have on-site coulomb repulsion for p-electron of oxygen atoms. • The metal vacancy converts XO{sub 2} (peroxide based materials) as “d{sup 0} magnet”. • Mechanical stability and hardness of pure, Zn and O-vacant ZnO{sub 2}. • Zn vacancies tune the optical properties of ZnO{sub 2}, indicates applications in wide area. - Abstract: Using first principles method we elaborately discuss the magnetic, elastic and optical properties of pure, Zn and O vacant ZnO{sub 2}. It is found that the electronic structure and band gap of ZnO{sub 2} is not sensitive to the active on-site Coulomb interaction term U{sub d}, but found to be depending on the term U{sub p}. The role of orbitals subject to the correlation is thus completely opposite for the case of ZnO{sub 2} in respect of ZnO. Interestingly, the Zn vacancy converts ZnO{sub 2} as “d{sup 0} magnet”. Indeed, our analysis show that, Zn vacancy transmuted O{sub 2}{sup 2−} state into O{sub 2}{sup δ+2−} state, indicating the partially filled π{sup ∗} states are the governing reason for the d{sup 0} magnetism. Both HSE06 and PBE0 functional confirm the same. The similar phenomena has been observed for other peroxide materials XO{sub 2} (X = Mg, Ca, Sr, Ba) studied here. Our results suggest that this class of materials can be studied further to exploit its potential in spintronic devices. Further the elastic properties have been estimated for pure ZnO{sub 2} at different pressures and for Zn and O vacant ZnO{sub 2} to know the stability of the system. Zn vacancy in ZnO{sub 2} also tunes optical properties, indicating its potential application in other areas.

  18. Structural, elastic, electronic and thermal properties of the cubic perovskite-type BaSnO 3

    Science.gov (United States)

    Bouhemadou, A.; Haddadi, K.

    2010-04-01

    First-principles calculations are performed to investigate the structural, elastic, electronic and thermal properties of the cubic perovskite-type BaSnO 3. The ground-state properties are in agreement with experimental data. The independent elastic constants, C11, C12 and C44, are calculated from direct computation of stresses generated by small strains. A linear pressure dependence of the elastic stiffnesses is found. From the theoretical elastic constants, we have computed the elastic wave velocities along [100], [110] and [111] directions. The shear modulus, Young's modulus, Poisson's ratio, Lamé's coefficients, average sound velocity and Debye temperature are estimated in the framework of the Voigt-Reuss-Hill approximation for ideal polycrystalline BaSnO 3 aggregate. Using the sX-LDA for the exchange-correlation potential, the calculated indirect fundamental band gap value is in very good agreement with the measured one. The analysis of the site-projected l-decomposed density of states, charge transfer and charge density shows that the bonding is of ionic nature. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the temperature effect on the lattice constant, bulk modulus, thermal expansion coefficient, heat capacity and Debye temperature is calculated.

  19. Evaluating elastic properties of heterogeneous soft tissue by surface acoustic waves detected by phase-sensitive optical coherence tomography

    Science.gov (United States)

    Li, Chunhui; Guan, Guangying; Li, Sinan; Huang, Zhihong; Wang, Ruikang K.

    2012-05-01

    The combined use of surface acoustic wave (SAW) and phase-sensitive optical coherence tomography (PhS-OCT) is useful to evaluate the elasticity of layered biological tissues, such as normal skin. However, the pathological tissue is often originated locally, leading to the alternation of mechanical properties along both axial and lateral directions. We present a feasibility study on whether the SAW technique is sensitive to detect the alternation of mechanical property along the lateral direction within tissue, which is important for clinical utility of this technique to localize diseased tissue. Experiments are carried out on purposely designed tissue phantoms and ex vivo chicken breast samples, simulating the localized change of elasticity. A PhS-OCT system is employed not only to provide the ultra-high sensitive measurement of the generated surface waves on the tissue surface, but also to provide the real time imaging of the tissue to assist the elasticity evaluation of the heterogeneous tissue. The experimental results demonstrate that with PhS-OCT used as a pressure sensor, the SAW is highly sensitive to the elasticity change of the specimen in both vertical and lateral directions with a sensing depth of ˜5 mm with our current system setup, thus promising its useful clinical applications where the quantitative elasticity of localized skin diseases is needed to aid in diagnosis and treatment.

  20. The Propagation of Seismic Waves in the Presence of Strong Elastic Property Contrasts

    Science.gov (United States)

    Saleh, R.; Jeyaraj, R.; Milkereit, B.; Liu, Q.; Valley, B.

    2012-12-01

    In an active underground mine there are many seismic activities taking place, such as seismic noises, blasts, tremors and microseismic events. In between the activities, the microseismic events are mainly used for monitoring purposes. The frequency content of microseismic events can be up to few KHz, which can result in wavelengths on the order of a few meters in hard rock environment. In an underground mine, considering the presence of both small wavelength and strong elastic contrasts, the simulation of seismic wave propagation is a challenge. With the recent availability of detailed 3D rock property models of mines, in addition to the development of efficient numerical techniques (such as Spectral Element Method (SEM)), and parallel computation facilities, a solution for such a problem is achievable. Most seismic wave scattering studies focus on large scales (>1 km) and weak elastic contrasts (velocity perturbations less than 10%). However, scattering in the presence of small-scale heterogeneities and large elastic contrasts is an area of ongoing research. In a mine environment, the presence of strong contrast discontinuities such as massive ore bodies, tunnels and infrastructure lead to discontinuities of displacement and/or stress tensor components, and have significant impact on the propagation of seismic waves. In order to obtain an accurate image of wave propagation in such a complex media, it is necessary to consider the presence of these discontinuities in numerical models. In this study, the effects of such a contrast are illustrated with 2D/3D modeling and compared with real broadband 3-component seismic data. The real broadband 3-component seismic data will be obtained in one of the Canadian underground mines in Ontario. One of the possible scenarios investigated in this study that may explain the observed complexity in seismic wavefield pattern in hard rock environments is the effect of near field displacements rather than far field. Considering the

  1. Effect of deposition temperature on morphological, magnetic and elastic properties of ultrathin Co49Pt51 films

    Science.gov (United States)

    Si Abdallah, F.; Chérif, S. M.; Bouamama, Kh.; Roussigné, Y.; Hsu, J.-H.

    2018-03-01

    Morphological, magnetic and elastic properties of 5 nm-thick Co49Pt51 films, sputtered on glass substrates, with 20 nm-thick Ta (seed) and Pt (buffer) layers were studied as function of the deposition temperature Td ranging between room temperature and 350° C. Atomic and magnetic force microscopy, vibrating sample magnetometer and Brillouin light scattering techniques were used to investigate the root mean square (RMS) roughness, the magnetic domain configuration, the coercive field (Hc), the perpendicular magnetic anisotropy (PMA), and the dynamic magnetic and elastic properties of the films with Td. The results show that surface uniformity was enhanced since the RMS roughness decreases with Td while magnetic domains typical of films with high PMA are observed. Hc and PMA are found to sensibly increase with Td. The dynamic magnetization behavior is characterized by magnetic modes related with the co-existence of hard and soft magnetic areas within the samples. The elastic properties of the stack were first analyzed by means of a model describing the main variation of the elastic wave frequencies within the frame of weighted average thickness, density, Young's modulus and Poisson coefficient of all the layers constituting the stacks. However, while Hc and PMA keep increasing with Td, a more precise experimental analysis of the mechanical behavior shows that the group velocity starts increasing and finally decreases with Td, suggesting that knowledge of the influence of Td on the mechanical properties of each individual layer composing the stack is required to obtain a more accurate analysis.

  2. Elastic properties of Na2 O–ZnO–ZnF2 –B2 O3 oxyfluoride glasses

    Indian Academy of Sciences (India)

    Administrator

    plex behaviour of the glass network. The results have been analysed in view of the modified borate glass net- work. Addition of ZnF2 into the pure glass seems to influence the borate network by replacement of B–O–B linkages with B–O–Zn. Keywords. Borate glasses; oxyfluoride glasses; elastic properties; dual role of Zn.

  3. Elastic properties of Na2 O–ZnO–ZnF2–B2 O3 oxyfluoride glasses

    Indian Academy of Sciences (India)

    Elastic properties of Na2O–ZnO–ZnF2–B2O3 oxyfluoride glasses with different ZnF2 concentrations have been investigated using ultrasonic velocity measurements at room temperature, at a frequency of 10 MHz. Glasses prepared by melt quenching method were suitably polished for the ultrasonic velocity measurements ...

  4. Anisotropy of the elastic properties of crystalline cellulose Iß from first principles density functional theory with Van der Waals interactions

    Science.gov (United States)

    Fernando L. Dri; Louis G. Jr. Hector; Robert J. Moon; Pablo D. Zavattieri

    2013-01-01

    In spite of the significant potential of cellulose nanocrystals as functional nanoparticles for numerous applications, a fundamental understanding of the mechanical properties of defect-free, crystalline cellulose is still lacking. In this paper, the elasticity matrix for cellulose Iß with hydrogen bonding network A was calculated using ab initio...

  5. Anisotropy and temperature dependence of structural, thermodynamic, and elastic properties of crystalline cellulose Iβ: a first-principles investigation

    Science.gov (United States)

    ShunLi Shang; Louis G. Hector Jr.; Paul Saxe; Zi-Kui Liu; Robert J. Moon; Pablo D. Zavattieri

    2014-01-01

    Anisotropy and temperature dependence of structural, thermodynamic and elastic properties of crystalline cellulose Iβ were computed with first-principles density functional theory (DFT) and a semi-empirical correction for van der Waals interactions. Specifically, we report the computed temperature variation (up to 500...

  6. Measuring the linear and nonlinear elastic properties of brain tissue with shear waves and inverse analysis.

    Science.gov (United States)

    Jiang, Yi; Li, Guoyang; Qian, Lin-Xue; Liang, Si; Destrade, Michel; Cao, Yanping

    2015-10-01

    We use supersonic shear wave imaging (SSI) technique to measure not only the linear but also the nonlinear elastic properties of brain matter. Here, we tested six porcine brains ex vivo and measured the velocities of the plane shear waves induced by acoustic radiation force at different states of pre-deformation when the ultrasonic probe is pushed into the soft tissue. We relied on an inverse method based on the theory governing the propagation of small-amplitude acoustic waves in deformed solids to interpret the experimental data. We found that, depending on the subjects, the resulting initial shear modulus [Formula: see text] varies from 1.8 to 3.2 kPa, the stiffening parameter [Formula: see text] of the hyperelastic Demiray-Fung model from 0.13 to 0.73, and the third- [Formula: see text] and fourth-order [Formula: see text] constants of weakly nonlinear elasticity from [Formula: see text]1.3 to [Formula: see text]20.6 kPa and from 3.1 to 8.7 kPa, respectively. Paired [Formula: see text] test performed on the experimental results of the left and right lobes of the brain shows no significant difference. These values are in line with those reported in the literature on brain tissue, indicating that the SSI method, combined to the inverse analysis, is an efficient and powerful tool for the mechanical characterization of brain tissue, which is of great importance for computer simulation of traumatic brain injury and virtual neurosurgery.

  7. Modifying the MRI, elastic stiffness and electrical properties of polyvinyl alcohol cryogel using irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Goharian, Mehran [Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4K1 (Canada); Moran, Gerald R. [Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4K1 (Canada); Imaging Division, Lawson Health Research Institute, London, Ontario (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario (Canada)], E-mail: morang@mcmaster.ca; Wilson, Kyle [Department of Medical Biophysics, University of Western Ontario, London, Ontario (Canada); Seymour, Colin; Jegatheesan, Aravinthan; Hill, Michael [Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4K1 (Canada); Thompson, R. Terry [Imaging Division, Lawson Health Research Institute, London, Ontario (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario (Canada); Campbell, Gordon [Department of Medical Biophysics, University of Western Ontario, London, Ontario (Canada); Integrated Manufacturing Technologies Institute, Medical Devices, NRC, London, Ontario (Canada)

    2007-10-15

    The aim of this work was to study the effect of radiation on the elastic stiffness, electrical and MRI properties of polyvinyl alcohol (PVA)-based cryogel (PVA-C). The PVA-C samples were irradiated with a {sup 60}C0 {gamma}-source, at 2.18 x 10{sup 6} Rads. The indentation measurements (an indication of elastic stiffness) reduced by about 14.6% for PVA-3C and 5.7% PVA-6C after irradiation, indicating that the material became harder/stiffer. It was found that MRI relaxation times provide an alternative and non-destructive method to evaluate the radiation effect on PVA-C. The T{sub 1} of PVA-C that had undergone three freeze thaw cycles decreased with irradiation by 10%, 25% and 35% at 1 T, 1.89 T and 3 T respectively. The T{sub 1} of PVA-C that had undergone six freeze thaw cycles decreased with irradiation by 18%, 15% and 11% at 1 T, 1.89 T and 3 T respectively. The T{sub 2} of PVA-C decreased with irradiation only at 1T, however this change is hypothesized to be due to the interaction of two spin pools in the gel. The electrical conductivity ({sigma}) and permittivity constant ({epsilon}) of the unirradiated and {gamma}-irradiated PVA-C samples were measured at different frequencies in the range 40 Hz to 1 MHz. The results demonstrated that the conductivity increased with irradiation by 50% for PVA-3C (three freeze thaw cycles) and 75% for PVA-6C (six freeze thaw cycles) at frequencies greater than 1 KHz.The permittivity decreased with irradiation up to 25% for 3C and 35% for 6C at frequencies less than 1 KHz.

  8. Investigations of structural, elastic, electronic and thermodynamic properties of lutetium filled skutterudite LuFe4P12 under pressure effect: FP-LMTO method

    Directory of Open Access Journals (Sweden)

    Boudia Keltouma

    2015-12-01

    Full Text Available Structural, elastic, electronic and thermodynamic properties of ternary cubic filled skutterudite compound were calculated. We have computed the elastic modulus and its pressure dependence. From the elastic parameter behavior, it is inferred that this compound is elastically stable and ductile in nature. Through the quasi-harmonic Debye model, in which phononic effects are considered, the effect of pressure P (0 to 50 GPa and temperature T (0 to 3000 °C on the lattice constant, elastic parameters, bulk modulus B, heat capacity, thermal expansion coefficient α, internal energy U, entropy S, Debye temperature θD, Helmholtz free energy A, and Gibbs free energy G are investigated.

  9. Elastic properties of superconducting bulk metallic glasses; Elastische Eigenschaften von supraleitenden massiven metallischen Glaesern

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Marius

    2015-07-01

    Within the framework of this thesis the elastic properties of a superconducting bulk metallic glass between 10 mK and 300 K were first investigated. In order to measure the entire temperature range, in particular the low temperature part, new experimental techniques were developed. Using an inductive readout scheme for a double paddle oscillator it was possible to determine the internal friction and the relative change of sound velocity of bulk metallic glasses with high precision. This allowed for a detailed comparison of the data with different models. The analysis focuses on the low temperature regime where the properties of glassy materials are governed by atomic tunneling systems as described by the tunneling model. The influence of conduction electrons in the normal conducting state and quasiparticles in the superconducting state of the glass were accounted for in the theoretical description, resulting in a good agreement over a large temperature range between measured data and prediction of the tunneling model. This allowed for a direct determination of the coupling constant between electrons and tunneling systems. In the vicinity of the transition temperature Tc the data can only be described if a modified distribution function of the tunneling parameters is applied.

  10. Elastic properties of model random three-dimensional open-cell solids

    Science.gov (United States)

    Roberts, A. P.; Garboczi, E. J.

    2002-01-01

    Most cellular solids are random materials, while practically all theoretical structure-property relations are for periodic models. To generate theoretical results for random models the finite element method (FEM) was used to study the elastic properties of open-cell solids. We have computed the density ( ρ) and microstructure dependence of the Young's modulus ( E) and Poisson's ratio ( ν) for four different isotropic random models. The models were based on Voronoi tessellations, level-cut Gaussian random fields, and nearest neighbour node-bond rules. These models were chosen to broadly represent the structure of foamed solids and other (non-foamed) cellular materials. At low densities, the Young's modulus can be described by the relation E∝ ρn. The exponent n and constant of proportionality depend on microstructure. We find 1.3common model of foams, became approximately incompressible ( ν≈0.5). This behaviour is not commonly observed experimentally. Our studies showed the result was robust to polydispersity and that a relatively large number (15%) of the bonds must be broken to significantly reduce the low-density Poission's ratio to ν≈0.33.

  11. Effect of elastic and plastic tensile mechanical loading on the magnetic properties of NGO electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Leuning, N., E-mail: nora.leuning@iem.rwth-aachen.de [Institute of Electrical Machines, RWTH Aachen University, D-52062 Aachen (Germany); Steentjes, S. [Institute of Electrical Machines, RWTH Aachen University, D-52062 Aachen (Germany); Schulte, M.; Bleck, W. [Steel Institute, RWTH Aachen University, D-52072 Aachen (Germany); Hameyer, K. [Institute of Electrical Machines, RWTH Aachen University, D-52062 Aachen (Germany)

    2016-11-01

    The magnetic properties of non-grain-oriented (NGO) electrical steels are highly susceptible to mechanical stresses, i.e., residual, external or thermal ones. For rotating electrical machines, mechanical stresses are inevitable and originate from different sources, e.g., material processing, machine manufacturing and operating conditions. The efficiency and specific losses are largely altered by different mechanical stress states. In this paper the effect of tensile stresses and plastic deformations on the magnetic properties of a 2.9 wt% Si electrical steel are studied. Particular attention is paid to the effect of magnetic anisotropy, i.e., the influence of the direction of applied mechanical stress with respect to the rolling direction. Due to mechanical stress, the induced anisotropy has to be evaluated as it is related to the stress-dependent magnetostriction constant and the grain alignment. - Highlights: • A detailed look at magnetic anisotropy of FeSi NGO electrical steel. • Study of magnetic behavior under elastic as well as plastic tensile stresses. • Correlation of magnetic behavior with microscopic deformation mechanisms. • Discussion of detrimental and beneficial effects of external stresses. • Loss separation at different polarizations and frequencies under increasing stress.

  12. Structural, elastic and electronic Properties of isotropic cubic crystals of carbon and silicon nanotubes : Density functional based tight binding calculations.

    Directory of Open Access Journals (Sweden)

    Alexander L. Ivanovskii

    2008-01-01

    Full Text Available Atomic models of cubic crystals (CC of carbon and graphene-like Si nanotubes are offered and their structural, cohesive, elastic and electronic properties are predicted by means of the DFTB method. Our main findings are that the isotropic crystals of carbon nanotubes adopt a very high elastic modulus B and low compressibility β, namely B = 650 GPa, β = 0.0015 1/GPa. In addition, these crystals preserve the initial conductivity type of their “building blocks”, i.e. isolated carbon and Si nanotubes. This feature may be important for design of materials with the selected conductivity type.

  13. EMTA’s Evaluation of the Elastic Properties for Fiber Polymer Composites Potentially Used in Hydropower Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Ba Nghiep; Paquette, Joshua

    2010-08-01

    Fiber-reinforced polymer composites can offer important advantages over metals where lightweight, cost-effective manufacturing and high mechanical performance can be achieved. To date, these materials have not been used in hydropower systems. In view of the possibility to tailor their mechanical properties to specific applications, they now have become a subject of research for potential use in hydropower systems. The first step in any structural design that uses composite materials consists of evaluating the basic composite mechanical properties as a function of the as-formed composite microstructure. These basic properties are the elastic stiffness, stress-strain response, and strength. This report describes the evaluation of the elastic stiffness for a series of common discontinuous fiber polymer composites processed by injection molding and compression molding in order to preliminarily estimate whether these composites could be used in hydropower systems for load-carrying components such as turbine blades. To this end, the EMTA (Copyright © Battelle 2010) predictive modeling tool developed at the Pacific Northwest National Laboratory (PNNL) has been applied to predict the elastic properties of these composites as a function of three key microstructural parameters: fiber volume fraction, fiber orientation distribution, and fiber length distribution. These parameters strongly control the composite mechanical performance and can be tailored to achieve property enhancement. EMTA uses the standard and enhanced Mori-Tanaka type models combined with the Eshelby equivalent inclusion method to predict the thermoelastic properties of the composite based on its microstructure.

  14. Composted municipal waste effect on chosen properties of calcareous soil

    Science.gov (United States)

    Hamidpour, M.; Afyuni, M.; Khadivi, E.; Zorpas, A.; Inglezakis, V.

    2012-10-01

    A 3-year field study was conducted to assess effects of composted municipal waste on some properties, distribution of Zn, Cu in a calcareous soil and uptake of these metals by wheat. The treatments were 0, 25, 50 and 100 Mg ha-1 of municipal solidwastewhichwas applied in three consecutive years. The application of composted municipal waste increased the saturated hydraulic conductivity, the aggregate stability,the organic carbon content and electrical conductivity, whereas it slightly decreased the soil pH and bulk density. A significant increase in the concentration of Zn and Cu were observed with increasing number and rate of compost application. The distribution of Zn and Cu between the different fractions in untreated and treated soils showed that the majority of Zn and Cu were in the residual form. Finally, the levels of Zn and Cu were higher in grains of wheat grown in composttreated plots compared to that grown in the control plots.

  15. Endothelial, cardiac muscle and skeletal muscle exhibit different viscous and elastic properties as determined by atomic force microscopy

    Science.gov (United States)

    Mathur, A. B.; Collinsworth, A. M.; Reichert, W. M.; Kraus, W. E.; Truskey, G. A.

    2001-01-01

    This study evaluated the hypothesis that, due to functional and structural differences, the apparent elastic modulus and viscous behavior of cardiac and skeletal muscle and vascular endothelium would differ. To accurately determine the elastic modulus, the contribution of probe velocity, indentation depth, and the assumed shape of the probe were examined. Hysteresis was observed at high indentation velocities arising from viscous effects. Irreversible deformation was not observed for endothelial cells and hysteresis was negligible below 1 microm/s. For skeletal muscle and cardiac muscle cells, hysteresis was negligible below 0.25 microm/s. Viscous dissipation for endothelial and cardiac muscle cells was higher than for skeletal muscle cells. The calculated elastic modulus was most sensitive to the assumed probe geometry for the first 60 nm of indentation for the three cell types. Modeling the probe as a blunt cone-spherical cap resulted in variation in elastic modulus with indentation depth that was less than that calculated by treating the probe as a conical tip. Substrate contributions were negligible since the elastic modulus reached a steady value for indentations above 60 nm and the probe never indented more than 10% of the cell thickness. Cardiac cells were the stiffest (100.3+/-10.7 kPa), the skeletal muscle cells were intermediate (24.7+/-3.5 kPa), and the endothelial cells were the softest with a range of elastic moduli (1.4+/-0.1 to 6.8+/-0.4 kPa) depending on the location of the cell surface tested. Cardiac and skeletal muscle exhibited nonlinear elastic behavior. These passive mechanical properties are generally consistent with the function of these different cell types.

  16. Hanford Site organic waste tanks: History, waste properties, and scientific issues

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, D.M.; Schulz, W.W.; Reynolds, D.A.

    1993-01-01

    Eight Hanford single-shell waste tanks are included on a safety watch list because they are thought to contain significant concentrations of various organic chemical. Potential dangers associated with the waste in these tanks include exothermic reaction, combustion, and release of hazardous vapors. In all eight tanks the measured waste temperatures are in the range 16 to 46[degree]C, far below the 250 to 380[degree]C temperatures necessary for onset of rapid exothermic reactions and initiation of deflagration. Investigation of the possibility of vapor release from Tank C-103 has been elevated to a top safety priority. There is a need to obtain an adequate number of truly representative vapor samples and for highly sensitive and capable methods and instruments to analyze these samples. Remaining scientific issues include: an understanding of the behavior and reaction of organic compounds in existing underground tank environments knowledge of the types and amounts of organic compounds in the tanks knowledge of selected physical and chemical properties of organic compounds source, composition, quality, and properties of the presently unidentified volatile organic compound(s) apparently evolving from Tank C-103.

  17. Hanford Site organic waste tanks: History, waste properties, and scientific issues. Hanford Tank Safety Project

    Energy Technology Data Exchange (ETDEWEB)

    Strachan, D.M.; Schulz, W.W.; Reynolds, D.A.

    1993-01-01

    Eight Hanford single-shell waste tanks are included on a safety watch list because they are thought to contain significant concentrations of various organic chemical. Potential dangers associated with the waste in these tanks include exothermic reaction, combustion, and release of hazardous vapors. In all eight tanks the measured waste temperatures are in the range 16 to 46{degree}C, far below the 250 to 380{degree}C temperatures necessary for onset of rapid exothermic reactions and initiation of deflagration. Investigation of the possibility of vapor release from Tank C-103 has been elevated to a top safety priority. There is a need to obtain an adequate number of truly representative vapor samples and for highly sensitive and capable methods and instruments to analyze these samples. Remaining scientific issues include: an understanding of the behavior and reaction of organic compounds in existing underground tank environments knowledge of the types and amounts of organic compounds in the tanks knowledge of selected physical and chemical properties of organic compounds source, composition, quality, and properties of the presently unidentified volatile organic compound(s) apparently evolving from Tank C-103.

  18. Acoustic and Elastic Properties of Glycerol in Oil-Based Gel Phantoms.

    Science.gov (United States)

    Cabrelli, Luciana C; Grillo, Felipe W; Sampaio, Diego R T; Carneiro, Antonio A O; Pavan, Theo Z

    2017-09-01

    Phantoms are important tools for image quality control and medical training. Many phantom materials have been proposed for ultrasound; most of them use water as the solvent, but these materials have disadvantages such as dehydration and low temporal stability if not properly stored. To overcome these difficulties, copolymer-in-oil gel was proposed as an inert and stable material; however, speed of sound for these materials is still lower than what is described for most biological tissues. Here, we propose the glycerol dispersion in oil-based gels to modify the acoustic and elastic properties of copolymer-in-oil phantoms. We manufactured copolymer-in-oil gels using styrene-ethylene/butylene-styrene (SEBS) in concentrations 8%-15%. We used 2 types of mineral oils with different viscosities. Glycerol was added in a volume fraction 0%-30% of the total amount of liquid. The acoustic (i.e., speed of sound, attenuation and backscattering) and the mechanical (i.e., density and Young's modulus) properties of the samples were within the range of values observed for soft tissues. The acoustic parameters of the samples were dependent on oil viscosity and glycerol concentration. The speed of sound ranged 1423 m/s - 1502 m/s, while the acoustic attenuation and the ultrasonic backscattering increased by adding glycerol. The density and the Young's moduli were less affected by the presence of glycerol. We conclude that glycerol can be used to control the acoustic parameters of copolymer-in-oil gels. Additionally, it opens the possibility of incorporating other oil-insoluble substances to control further properties of the phantom. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. First principles calculation of elastic and magnetic properties of Cr-based full-Heusler alloys

    Energy Technology Data Exchange (ETDEWEB)

    Aly, Samy H., E-mail: samy.ha.aly@gmail.com; Shabara, Reham M., E-mail: rehamph@hotmail.com

    2014-06-01

    We present an ab-initio study of the elastic and magnetic properties of Cr-based full-Heusler alloys within the first-principles density functional theory. The lattice constant, magnetic moment, bulk modulus and density of states are calculated using the full-potential nonorthogonal local-orbital minimum basis (FPLO) code in the Generalized Gradient Approximation (GGA) scheme. Only the two alloys Co{sub 2}CrSi and Fe{sub 2}CrSi are half-metallic with energy gaps of 0.88 and 0.55 eV in the spin-down channel respectively. We have predicted the metallicity state for Fe{sub 2}CrSb, Ni{sub 2}CrIn, Cu{sub 2}CrIn, and Cu{sub 2}CrSi alloys. Fe{sub 2}CrSb shows a strong pressure dependent, e.g. exhibits metallicity at zero pressure and turns into a half-metal at P≥10 GPa. The total and partial magnetic moments of these alloys were studied under higher pressure, e.g. in Co{sub 2}CrIn, the total magnetic moment is almost unchanged under higher pressure up to 500 GPa. - Highlights: • This study is a novel study on properties of Ni{sub 2}CrIn, Cu{sub 2}CrIn, Cu{sub 2}CrSi and Fe{sub 2}CrSb. • We have calculated the lattice constant, bulk modulus, energy gap, and DOS. • Half-metallic property is found only in both Co{sub 2}CrSi and Fe{sub 2}CrSi alloys. • Total and partial magnetic moments were studied under high pressure.

  20. Evaluation of visco-elastic properties of conditioned wheat kernels and their doughs using a compression test under small strain.

    Science.gov (United States)

    Ponce-García, Néstor; Ramírez-Wong, Benjamín; Torres-Chávez, Patricia I; Figueroa-Cárdenas, Juan de Dios; Serna-Saldívar, Sergio O; Cortez-Rocha, Mario O; Escalante-Aburto, Anayansi

    2017-03-01

    The aim of this research was to evaluate the visco-elastic properties of conditioned wheat kernels and their doughs by applying the compression test under a small strain. Conditioned wheat kernels and their doughs, from soft and hard wheat classes were evaluated for total work (Wt ), elastic work (We ) and plastic work (Wp ). Soft wheat kernels showed lower We than Wp , while the hard wheat kernels had a We that was higher than Wp . Regarding dough visco-elasticity, cultivars from soft and hard wheat showed higher Wp than We . The degree of elasticity (DE%) of the conditioned wheat kernel related to its dough decreased ∼46% in both wheat classes. The Wt , We and Wp from the soft wheat kernel and dough correlated with physico-chemical and farinographic flour tests. The Wt , Wp and the maximum compression force (Fmax ) of the dough from hard wheat class presented highly significant negative correlations with wet gluten. The visco-elasticity parameters from compression test presented significant differences among conditioned wheat classes and their doughs. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. Dependence of Some Mechanical Properties of Elastic Bands on the Length and Load Time

    Science.gov (United States)

    Triana, C. A.; Fajardo, F.

    2012-01-01

    We present a study of the maximum stress supported by elastics bands of nitrile as a function of the natural length and the load time. The maximum tension of rupture and the corresponding variation in length were found by measuring the elongation of an elastic band when a mass is suspended from its free end until it reaches the breaking point. The…

  2. Are the dynamics of silicate glasses and glass-forming liquids embedded in their elastic properties?

    DEFF Research Database (Denmark)

    Smedskjær, Morten Mattrup; Mauro, John C.

    According to the elastic theory of the glass transition, the dynamics of glasses and glass-forming liquids are controlled by the evolution of shear modulus. In particular, the elastic shoving model expresses dynamics in terms of an activation energy required to shove aside the surrounding atoms, ...

  3. Multi scale modeling of the elastic properties of polymer-clay nanocomposites

    Science.gov (United States)

    Pahlavan Pour, Maryam

    Polymer-Clay Nanocomposites (PCN) are known to improve the mechanical properties of bulk polymers, even for modest clay loadings. This enhancement is due to the high aspect ratio and mechanical properties of the nanoclay platelets. Additionally, the interphase zone created by altered polymer chains in the vicinity of the nanoclays plays an important reinforcing role. Several analytical approaches exist for predicting the elastic properties of PCN, ranging from simplified two-step models to more complex one-step methods. However, no thorough study has yet rigorously verified the accuracy of these models. On the other hand, the numerical models that are commonly used to evaluate the analytical models are still far from modeling the real PCN microstructure reported in the literature. For example, most of the models have failed to model the detailed 3D microstructure considering randomly positioned reinforcing particles, the large nanoclay aspect ratio and the explicit incorporation of the constituent phases. More significantly, most of numerical studies have been reported without a thorough determination of the appropriate Representative Volume Element (RVE) due its computational burden, resulting in benchmark results of questionable accuracy. The main purpose of this thesis was to evaluate the accuracy of homogenization models for predicting the mechanical behavior of nanoclay nanocomposites. First, the validity of commonly used analytical micromechanical models for the prediction of exfoliated PCN elastic properties was evaluated with the help of 3D Finite Element (FE) simulations. In particular, special attention was devoted to the interphase around the nanoclays. The modeling strategy was a two-step procedure relying on the Effective Particle (EP) concept, in which the multi-layer reinforcing stacks were replaced by homogenized particles. The accuracy of the numerical models was guaranteed, within a given tolerance, by rigorous determination of the RVE. It was

  4. First-principles study of structural stability, electronic, optical and elastic properties of binary intermetallic: PtZr

    Energy Technology Data Exchange (ETDEWEB)

    Pagare, Gitanjali, E-mail: gita-pagare@yahoo.co.in [Department of Physics, Sarojini Naidu Government Girls P. G. Autonomous College, Bhopal-462016 (India); Jain, Ekta, E-mail: jainekta05@gmail.com [Department of Physics, Government M. L. B. Girls P. G. Autonomous College, Bhopal-462002 (India); Sanyal, S. P., E-mail: sps.physicsbu@gmail.com [Department of Physics, Barkatullah University, Bhopal-462026 (India)

    2016-05-06

    Structural, electronic, optical and elastic properties of PtZr have been studied using the full-potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). The energy against volume and enthalpy vs. pressure variation in three different structures i.e. B{sub 1}, B{sub 2} and B{sub 3} for PtZr has been presented. The equilibrium lattice parameter, bulk modulus and its pressure derivative have been obtained using optimization method for all the three phases. Furthermore, electronic structure was discussed to reveal the metallic character of the present compound. The linear optical properties are also studied under zero pressure for the first time. Results on elastic properties are obtained using generalized gradient approximation (GGA) for exchange correlation potentials. Ductile nature of PtZr compound is predicted in accordance with Pugh’s criteria.

  5. Exploring structural, electronic and thermo-elastic properties of metallic AMoO3 (A = Pb, Ba, Sr) molybdates

    Science.gov (United States)

    Tariq, Saad; Jamil, M. Imran; Sharif, Azeem; Ramay, Shahid Mahmood; Ahmad, Hasnain; ul Qamar, Noor; Tahir, Bashir

    2018-01-01

    The structural, electronic and thermodynamic properties of AMoO3 (A = Pb, Ba and Sr) molybdates have been investigated by deploying density functional theory. Computed elastic constants and corresponding properties is the first comparative report on AMoO3.The elastic properties match well with the available literature. Results have shown that the studied compounds exhibit stable anti-ferromagnetic, ductile cubic phase along with metallic attributes. Electron spin density contours and DOS were used to shed light on surface morphology of metal-oxide-metal type of mixed bonding. By analyzing enthalpy of formations for AMoO3, SrMoO3 has found to be the most stable than Pb and Ba molybdates. Our results are predictions for future experimentations to develop electronic devices based on studied compounds.

  6. Glass Property Data and Models for Estimating High-Level Waste Glass Volume

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, John D.; Fluegel, Alexander; Kim, Dong-Sang; Hrma, Pavel R.

    2009-10-05

    This report describes recent efforts to develop glass property models that can be used to help estimate the volume of high-level waste (HLW) glass that will result from vitrification of Hanford tank waste. The compositions of acceptable and processable HLW glasses need to be optimized to minimize the waste-form volume and, hence, to save cost. A database of properties and associated compositions for simulated waste glasses was collected for developing property-composition models. This database, although not comprehensive, represents a large fraction of data on waste-glass compositions and properties that were available at the time of this report. Glass property-composition models were fit to subsets of the database for several key glass properties. These models apply to a significantly broader composition space than those previously publised. These models should be considered for interim use in calculating properties of Hanford waste glasses.

  7. Material and elastic properties of Al-tobermorite in ancient roman seawater concrete

    KAUST Repository

    Jackson, Marie D.

    2013-05-28

    The material characteristics and elastic properties of aluminum-substituted 11 Å tobermorite in the relict lime clasts of 2000-year-old Roman seawater harbor concrete are described with TG-DSC and 29Si MAS NMR studies, along with nanoscale tomography, X-ray microdiffraction, and high-pressure X-ray diffraction synchrotron radiation applications. The crystals have aluminum substitution for silicon in tetrahedral bridging and branching sites and 11.49(3) Å interlayer (002) spacing. With prolonged heating to 350°C, the crystals exhibit normal behavior. The experimentally measured isothermal bulk modulus at zero pressure, K0, 55 ±5 GPa, is less than ab initio and molecular dynamics models for ideal tobermorite with a double-silicate chain structure. Even so, K0, is substantially higher than calcium-aluminum-silicate-hydrate binder (C-A-S-H) in slag concrete. Based on nanoscale tomographic study, the crystal clusters form a well connected solid, despite having about 52% porosity. In the pumiceous cementitious matrix, Al-tobermorite with 11.27 Å interlayer spacing is locally associated with phillipsite, similar to geologic occurrences in basaltic tephra. The ancient concretes provide a sustainable prototype for producing Al-tobermorite in high-performance concretes with natural volcanic pozzolans. © 2013 The American Ceramic Society.

  8. Optical and elastic properties of diamond-like carbon with metallic inclusions: A theoretical study

    Science.gov (United States)

    Tritsaris, Georgios A.; Mathioudakis, Christos; Kelires, Pantelis C.; Kaxiras, Efthimios

    2012-11-01

    A tough material commonly used in coatings is diamond-like carbon (DLC), that is, amorphous carbon with content in four-fold coordinated C higher than ˜70%, and its composites with metal inclusions. This study aims to offer useful guidelines for the design and development of metal-containing DLC coatings for solar collectors, where the efficiency of the collector depends critically on the performance of the absorber coating. We use first-principles calculations based on density functional theory to study the structural, electronic, optical, and elastic properties of DLC and its composites with Ag and Cu inclusions at 1.5% and 3.0% atomic concentration, to evaluate their suitability for solar thermal energy harvesting. We find that with increasing metal concentration optical absorption is significantly enhanced while at the same time, the composite retains good mechanical strength: DLC with 70-80% content in four-fold coordinated C and small metal concentrations (Young's modulus higher than 300 and 500 GPa, respectively).

  9. Acoustic tests of elastic and microplastic properties of V-Ti-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, V.M. [Fiziko-Ehnergeticheskij Institut, Obninsk (Russian Federation); Rezvoushkin, A.V. [Fiziko-Ehnergeticheskij Institut, Obninsk (Russian Federation); Kardashev, B.K. [Ioffe Physico-Technical Inst., St. Petersburg (Russian Federation)

    1996-10-01

    The non-linear acoustic properties of V-10Ti-5Cr alloy before and after proton irradiation (dose 2.2 x 10{sup 14} p/cm{sup 2}) were investigated using a composite oscillator technique at longitudinal vibration frequencies of about 100 kHz. Acoustic parameters (decrement and resonance frequency) of the samples demonstrated noticeable amplitude dependencies of hysteretic type both in undeformed and deformed states. An unusual influence of plastical pre-straining on irradiated sample was found which resulted in small decreases in damping and increases in resonance frequency, and hence, of the elastic modulus. Damping in an irradiated sample was higher and its resonant frequency was lower as compared with a non-irradiated sample. This acoustic effect correlated with the results of microhardness and yield strength measurements. The experimental results are discussed in the framework of a model which predicts the creation by proton irradiation of defects which aid the motion of dislocations in V-alloys. (orig.).

  10. A novel chitin binding crayfish molar tooth protein with elasticity properties.

    Directory of Open Access Journals (Sweden)

    Jenny Tynyakov

    Full Text Available The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate. This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties.

  11. A novel chitin binding crayfish molar tooth protein with elasticity properties.

    Science.gov (United States)

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties.

  12. First principles calculation of elastic and magnetic properties of Cr-based full-Heusler alloys

    Science.gov (United States)

    Aly, Samy H.; Shabara, Reham M.

    2014-06-01

    We present an ab-initio study of the elastic and magnetic properties of Cr-based full-Heusler alloys within the first-principles density functional theory. The lattice constant, magnetic moment, bulk modulus and density of states are calculated using the full-potential nonorthogonal local-orbital minimum basis (FPLO) code in the Generalized Gradient Approximation (GGA) scheme. Only the two alloys Co2CrSi and Fe2CrSi are half-metallic with energy gaps of 0.88 and 0.55 eV in the spin-down channel respectively. We have predicted the metallicity state for Fe2CrSb, Ni2CrIn, Cu2CrIn, and Cu2CrSi alloys. Fe2CrSb shows a strong pressure dependent, e.g. exhibits metallicity at zero pressure and turns into a half-metal at P≥10 GPa. The total and partial magnetic moments of these alloys were studied under higher pressure, e.g. in Co2CrIn, the total magnetic moment is almost unchanged under higher pressure up to 500 GPa.

  13. First-principles study of the elastic and thermodynamic properties of thorium hydrides at high pressure

    Science.gov (United States)

    Xiao-Lin, Zhang; Yuan-Yuan, Wu; Xiao-Hong, Shao; Yong, Lu; Ping, Zhang

    2016-05-01

    The high pressure behaviors of Th4H15 and ThH2 are investigated by using the first-principles calculations based on the density functional theory (DFT). From the energy-volume relations, the bct phase of ThH2 is more stable than the fcc phase at ambient conditions. At high pressure, the bct ThH2 and bcc Th4H15 phases are more brittle than they are at ambient pressure from the calculated elastic constants and the Poisson ratio. The thermodynamic stability of the bct phase ThH2 is determined from the calculated phonon dispersion. In the pressure domain of interest, the phonon dispersions of bcc Th4H15 and bct ThH2 are positive, indicating the dynamical stability of these two phases, while the fcc ThH2 is unstable. The thermodynamic properties including the lattice vibration energy, entropy, and specific heat are predicted for these stable phases. The vibrational free energy decreases with the increase of the temperature, and the entropy and the heat capacity are proportional to the temperature and inversely proportional to the pressure. As the pressure increases, the resistance to the external pressure is strengthened for Th4H15 and ThH2. Project supported by the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China.

  14. High-pressure structural and elastic properties of Tl₂O₃

    Energy Technology Data Exchange (ETDEWEB)

    Gomis, O., E-mail: osgohi@fis.upv.es; Vilaplana, R. [Centro de Tecnologías Físicas, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Santamaría-Pérez, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, 46100 Burjassot (Spain); Earth Sciences Department, University College London, Gower Street, WC1E 6BT London (United Kingdom); Ruiz-Fuertes, J. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Edificio de Investigación, C/Dr. Moliner 50, 46100 Burjassot (Spain); Geowissenschaften, Goethe-Universität, Altenhöferallee 1, 60438 Frankfurt am Main (Germany); Sans, J. A.; Manjón, F. J.; Mollar, M. [Instituto de Diseño para la Fabricación y Producción Automatizada, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); and others

    2014-10-07

    The structural properties of Thallium (III) oxide (Tl₂O₃) have been studied both experimentally and theoretically under compression at room temperature. X-ray powder diffraction measurements up to 37.7 GPa have been complemented with ab initio total-energy calculations. The equation of state of Tl₂O₃ has been determined and compared to related compounds. It has been found experimentally that Tl₂O₃ remains in its initial cubic bixbyite-type structure up to 22.0 GPa. At this pressure, the onset of amorphization is observed, being the sample fully amorphous at 25.2 GPa. The sample retains the amorphous state after pressure release. To understand the pressure-induced amorphization process, we have studied theoretically the possible high-pressure phases of Tl₂O₃. Although a phase transition is theoretically predicted at 5.8 GPa to the orthorhombic Rh₂O₂-II-type structure and at 24.2 GPa to the orthorhombic α-Gd₂S₃-type structure, neither of these phases were observed experimentally, probably due to the hindrance of the pressure-driven phase transitions at room temperature. The theoretical study of the elastic behavior of the cubic bixbyite-type structure at high-pressure shows that amorphization above 22 GPa at room temperature might be caused by the mechanical instability of the cubic bixbyite-type structure which is theoretically predicted above 23.5 GPa.

  15. Correlating elastic properties and molecular organization of an ionic organic nanostructure

    Science.gov (United States)

    Eskelsen, Jeremy R.; Qi, Yun; Schneider-Pollack, Samantha; Schmitt, Samantha; Hipps, K. W.; Mazur, Ursula

    2013-12-01

    Mechanical and structural properties of ionically self-assembled nanostructures of meso-tetra(4-sulfonatophenyl)porphyrin (TSPP) and meso-tetra(4-pyridyl)porphyrin (TPyP) are presented. This is the first time that elastic modulus of an ionic porphyrin nanostructure has been reported. X-ray photoelectron spectroscopy (XPS), UV-visible spectra, and elemental analysis all support a stoichiometric 1 : 1 TSPP to TPyP composition. Atomic force microscopy (AFM) revealed that the porphyrin nanostructure is composed of stacked ribbons about 20 nm tall, 70 nm wide, and several microns in length. High resolution transmission electron microscopy (HRTEM) images showed clear lattice fringes 1.5 +/- 0.2 nm in width aligned along the length of the nanorod. Selected area electron diffraction (SAED) and powder X-ray diffraction patterns of TSPP:TPyP are consistent with an orthorhombic system and space group Imm2 with lattice parameters a = 26.71 Å, b = 20.16 Å, and c = 8.61 Å. Crystallographic data is consistent with an arrangement of alternating face-to-face TSPP and TPyP molecules forming ordered columns along the length of the nanorods. The structural integrity of the solid is attributed to combined noncovalent interactions that include ionic, hydrogen bonding, and π-π interactions. The values of Young's modulus obtained for the crystalline TSPP:TPyP nanorods averaged 6.5 +/- 1.3 GPa. This modulus is comparable to those reported for covalently bonded flexible polymeric systems. The robust bonding character of the TSPP:TPyP nanostructures combined with their mechanical properties makes them excellent candidates for flexible optoelectronic devices.Mechanical and structural properties of ionically self-assembled nanostructures of meso-tetra(4-sulfonatophenyl)porphyrin (TSPP) and meso-tetra(4-pyridyl)porphyrin (TPyP) are presented. This is the first time that elastic modulus of an ionic porphyrin nanostructure has been reported. X-ray photoelectron spectroscopy (XPS), UV

  16. Robust and Elastic Polymer Membranes with Tunable Properties for Gas Separation.

    Science.gov (United States)

    Cao, Peng-Fei; Li, Bingrui; Hong, Tao; Xing, Kunyue; Voylov, Dmitry N; Cheng, Shiwang; Yin, Panchao; Kisliuk, Alexander; Mahurin, Shannon M; Sokolov, Alexei P; Saito, Tomonori

    2017-08-09

    Polymer membranes with the capability to process a massive volume of gas are especially attractive for practical applications of gas separation. Although much effort has been devoted to develop novel polymer membranes with increased selectivity, the overall gas-separation performance and lifetime of membrane are still negatively affected by the weak mechanical performance, low plasticization resistance and poor physical aging tolerance. Recently, elastic polymer membranes with tunable mechanical properties have been attracting significant attentions due to their tremendous potential applications. Herein, we report a series of urethane-rich PDMS-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation. The cross-link density of U-PDMS-NWs is tailored by varying the molecular weight (Mn) of PDMS. The U-PDMS-NWs show up to 400% elongation and tunable Young's modulus (1.3-122.2 MPa), ultimate tensile strength (1.1-14.3 MPa), and toughness (0.7-24.9 MJ/m(3)). All of the U-PDMS-NWs exhibit salient gas-separation performance with excellent thermal resistance and aging tolerance, high gas permeability (>100 Barrer), and tunable gas selectivity (up to α[PCO2/PN2] ≈ 41 and α[PCO2/PCH4] ≈ 16). With well-controlled mechanical properties and gas-separation performance, these U-PDMS-NW can be used as a polymer-membrane platform not only for gas separation but also for other applications such as microfluidic channels and stretchable electronic devices.

  17. Optimizing Thermal-Elastic Properties of C/C–SiC Composites Using a Hybrid Approach and PSO Algorithm

    Directory of Open Access Journals (Sweden)

    Yingjie Xu

    2016-03-01

    Full Text Available Carbon fiber-reinforced multi-layered pyrocarbon–silicon carbide matrix (C/C–SiC composites are widely used in aerospace structures. The complicated spatial architecture and material heterogeneity of C/C–SiC composites constitute the challenge for tailoring their properties. Thus, discovering the intrinsic relations between the properties and the microstructures and sequentially optimizing the microstructures to obtain composites with the best performances becomes the key for practical applications. The objective of this work is to optimize the thermal-elastic properties of unidirectional C/C–SiC composites by controlling the multi-layered matrix thicknesses. A hybrid approach based on micromechanical modeling and back propagation (BP neural network is proposed to predict the thermal-elastic properties of composites. Then, a particle swarm optimization (PSO algorithm is interfaced with this hybrid model to achieve the optimal design for minimizing the coefficient of thermal expansion (CTE of composites with the constraint of elastic modulus. Numerical examples demonstrate the effectiveness of the proposed hybrid model and optimization method.

  18. Density functional calculations of elastic properties of portlandite, Ca(OH)(2)

    DEFF Research Database (Denmark)

    Laugesen, Jakob Lund

    2005-01-01

    elasticity, applying a least-square method. Young's modulus and bulk modulus are calculated from the stiffness matrix. The results are compared with the Brillouin zone spectroscopy results of F. Holuj et al. [F. Holuj, M. Drozdowski, M. Czajkowski, Brillouin spectrum of Ca(OH)(2), Solid State Commun., 56 (12......The elastic constants of portlandite, Ca(OH)(2), are calculated by use of density functional theory. A lattice optimization of an infinite (periodic boundary conditions) lattice is performed on which strains are applied. The elastic constants are extracted by minimizing Hooke's law of linear...

  19. First-principles study of structural stabilities, elastic and electronic properties of transition metal monocarbides (TMCs) and mononitrides (TMNs)

    Energy Technology Data Exchange (ETDEWEB)

    Rached, H.; Rached, D.; Benalia, S. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Reshak, A.H., E-mail: maalidph@yahoo.co.uk [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Rabah, M. [Laboratoire des Matériaux Magnétiques, Faculté des Sciences, Université Djillali Liabès de Sidi Bel-Abbès, Sidi Bel-Abbès 22000 (Algeria); Khenata, R. [Laboratoire de Physique Quantique et de Modélisation Mathématique de la Matière (LPQ3M), université de Mascara, Mascara 29000 (Algeria); Bin Omran, S. [Department of Physics and Astronomy, Faculty of Science, King Saud University, Riyadh 11451 (Saudi Arabia)

    2013-12-16

    The structural stabilities, elastic and electronic properties of 5d transition metal mononitrides (TMNs) XN with (X = Ir, Os, Re, W and Ta) and 5d transition metal monocarbides (TMCs) XC with (X = Ir, Os, Re and Ta) were investigated using the full-potential linear muffin-tin orbital (FP-LMTO) method, in the framework of the density functional theory (DFT) within the local density approximation (LDA) for the exchange correlation functional. The ground state quantities such as the lattice parameter, bulks modulus and its pressure derivatives for the six considered crystal structures, Rock-salt (B1), CsCl (B2), zinc-blend (B3), Wurtzite (B4), NiAs (B8{sub 1}) and the tungsten carbides (B{sub h}) are calculated. The elastic constants of TMNs and TMCs compounds in its different stable phases are determined by using the total energy variation with strain technique. The elastic modulus for polycrystalline materials, shear modulus (G), Young's modulus (E), and Poisson's ratio (ν) are calculated. The Debye temperature (θ{sub D}) and sound velocities (v{sub m}) were also derived from the obtained elastic modulus. The analysis of the hardness of the herein studied compounds classifies OsN – (B4 et B8{sub 1}), ReN – (B8{sub 1}), WN – (B8{sub 1}) and OsC – (B8{sub 1}) as superhard materials. Our results for the band structure and densities of states (DOS), show that TMNs and TMCs compounds in theirs energetically and mechanically stable phase has metallic characteristic with strong covalent nature Metal–Nonmetal elements. - Highlights: • Structural stabilities, elastic, electronic properties of 5d TMNs XN are investigated. • 5d TMCs XC with (X = Ir, Os, Re and Ta) were investigated. • The ground state properties for the six considered crystal structure are calculated. • The elastic constants of TMNs and TMCs in its different stable phases are determined. • The elastic modulus for polycrystalline materials, G, E, and ν are calculated.

  20. Reactive Extrusion of Polyethylene Terephthalate Waste and Investigation of Its Thermal and Mechanical Properties after Treatment

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Mohsin

    2017-01-01

    Full Text Available This study investigates treating polyethylene terephthalate (PET waste water bottles with different mass of ethylene glycol (EG using reactive extrusion technique at a temperature of 260°C. The study puts emphases on evaluating the thermal, mechanical, and chemical characteristics of the treated polyethylene terephthalate. The properties of the treated PET from the extruder were analyzed using FT-IR, TGA, DSC, and nanoindentation. The melt flow indexes (MFI of both treated and untreated PET were also measured and compared. Thermal properties such as melting temperature (Tm for treating PET showed an inversely proportional behavior with the EG concentrations. The FT-IR analysis was used to investigate the formation of new linkages like hydrogen bonds between PET and EG due to the hydroxyl and carbonyl groups. Nanoindentation results revealed that both the mechanical characteristics, elastic modulus and hardness, decrease with increasing EG concentration. On the other hand, the melt flow index of treated PET exhibited an increase with increasing EG concentration in the PET matrix.

  1. Ultrasound (US transducer of higher operating frequency detects photoacoustic (PA signals due to the contrast in elastic property

    Directory of Open Access Journals (Sweden)

    Mayanglambam Suheshkumar Singh

    2016-02-01

    Full Text Available We report our study that shows selection in operating frequency of US-transducer used for boundary detection of PA-signals, which result due to the contrast in elastic property distribution ( E ( r → in sample material other than that of optical absorption coefficient (μa. Studies were carried out, experimentally, in tissue-mimicking Agar phantoms employing acoustic resolution photoacoustic microscopy (AR-PAM system as an imaging unit. In the experiments, various transducers having different operating frequencies, ranging from 1MHz to 50MHz, were employed for studying frequency response of the photoacoustic signals. The study shows that, for detecting photoacoustic signals due to the contrast in elastic property, ultrasound transducer with higher operating frequency (∼50MHz is demanded.

  2. Structural, electronic and elastic properties of REIr{sub 2} (RE=La and Ce) Laves phase compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shrivastava, Deepika, E-mail: deepika89shrivastava@gmail.com; Fatima, Bushra; Sanyal, Sankar P. [Department of Physics, Barkatullah University, Bhopal, 462026 (India)

    2016-05-23

    REIr{sub 2} (RE = La and Ce) Laves phase intermetallic compounds were investigated with respect to their structural, electronic and elastic properties using full potential linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation (GGA) as implemented in WIEN2k code. The ground state properties such as lattice constants (a{sub 0}), bulk modulus (B), pressure derivative of bulk modulus (B′) and density of state at Fermi level N(E{sub F}) have been obtained by optimization method. The electronic structure (BS, TDOS and PDOS) reveals that these Laves phase compounds are metallic in nature. The calculated elastic constants indicate that these compounds are mechanically stable at ambient pressure and found to be ductile in nature.

  3. (2+1)-dimensional compacton solutions with and without completely elastic interaction properties

    CERN Document Server

    Lou Sen Yue

    2002-01-01

    Taking the (2+1)-dimensional Broer-Kaup-Kupershmidt system as a simple example, some special types of (2+1)-dimensional compacton solutions are constructed. It is shown that there is quite rich interaction behaviour between two travelling compactons. For some types of compactons, the interactions among them may not be completely elastic. For some others, the interactions are completely elastic. There is no phase shift for the interactions of the (2+1)-dimensional compactons discussed in this paper.

  4. Effect of AlF3 on the Density and Elastic Properties of Zinc Tellurite Glass Systems

    Directory of Open Access Journals (Sweden)

    Zainal Abidin Talib

    2012-08-01

    Full Text Available This paper presents the results of the physical and elastic properties of the ternary zinc oxyfluoro tellurite glass system. Systematic series of glasses (AlF3x(ZnOy(TeO2z with x = 0–19, y = 0–20 and z = 80, 85, 90 mol% were synthesized by the conventional rapid melt quenching technique. The composition dependence of the physical, mainly density and molar volume, and elastic properties is discussed in term of the AlF3 modifiers addition that are expected to produce quite substantial changes in their physical properties. The absence of any crystalline peaks in the X-ray diffraction (XRD patterns of the present glass samples indicates the amorphous nature. The addition of AlF3 lowered the values of the densities in ternary oxyfluorotellurite glass systems. The longitudinal and transverse ultrasonic waves propagated in each glass sample were measured using a MBS8020 ultrasonic data acquisition system. All the velocity data were taken at 5 MHz frequency and room temperature. The longitudinal modulus (L, shear modulus (G, Young’s modulus (E, bulk modulus (K and Poisson’s ratio ( are obtained from both velocities data and their respective density. Experimental data shows the density and elastic moduli of each AlF3-ZnO-TeO2 series are found strongly depend upon the glass composition. The addition of AlF3 modifiers into the zinc tellurite causes substantial changes in their density, molar volume as well as their elastic properties.

  5. Numerical investigation of the influence of technological parameters of manufacturing on the elastic properties of short-fiber composite materials

    OpenAIRE

    Альтенбах, Х.; Науменко, К.; Львов, Г. И.; Пилипенко, С. Н.

    2003-01-01

    The paper presents a model which allows to estimate the elastic properties of thin-walled structures manufactured by means of injection molding. The starting point is the numerical prediction of the microstructure of the short fiber reinforced composite induced during the filling stage of the manufacturing process. For this purpose the commercial program Moldflow Plastic Insight® is used. The result of the filling simulation characterizing the fiber microstructure is the second rank orientati...

  6. Effect of AlF3 on the Density and Elastic Properties of Zinc Tellurite Glass Systems

    Science.gov (United States)

    Sidek, Haji Abdul Aziz; Rosmawati, Shaharuddin; Halimah, Mohamed Kamari; Matori, Khamirul Amin; Talib, Zainal Abidin

    2012-01-01

    This paper presents the results of the physical and elastic properties of the ternary zinc oxyfluoro tellurite glass system. Systematic series of glasses (AlF3)x(ZnO)y(TeO2)z with x = 0–19, y = 0–20 and z = 80, 85, 90 mol% were synthesized by the conventional rapid melt quenching technique. The composition dependence of the physical, mainly density and molar volume, and elastic properties is discussed in term of the AlF3 modifiers addition that are expected to produce quite substantial changes in their physical properties. The absence of any crystalline peaks in the X-ray diffraction (XRD) patterns of the present glass samples indicates the amorphous nature. The addition of AlF3 lowered the values of the densities in ternary oxyfluorotellurite glass systems. The longitudinal and transverse ultrasonic waves propagated in each glass sample were measured using a MBS8020 ultrasonic data acquisition system. All the velocity data were taken at 5 MHz frequency and room temperature. The longitudinal modulus (L), shear modulus (G), Young’s modulus (E), bulk modulus (K) and Poisson’s ratio (σ) are obtained from both velocities data and their respective density. Experimental data shows the density and elastic moduli of each AlF3-ZnO-TeO2 series are found strongly depend upon the glass composition. The addition of AlF3 modifiers into the zinc tellurite causes substantial changes in their density, molar volume as well as their elastic properties.

  7. Structural, elastic and electronic properties of new antiperovskite-type superconductor ZnNNi{sub 3} from first-principles

    Energy Technology Data Exchange (ETDEWEB)

    Okoye, C.M.I., E-mail: okoyecmi@yahoo.co [Department of Physics and Astronomy, University of Nigeria, Nsukka (Nigeria)

    2010-03-15

    A theoretical study of the structural, elastic and electronic properties of a new antiperovskite-type nitrogen-based superconductor ZnN{sub y}Ni{sub 3}, y=1.012+-0.208 has been performed on the stiochiometric compound, ZnNNi{sub 3}, using the augmented plane waves plus local orbital (APW+lo) method within the framework of density functional theory. This is compared with the isostructural non-superconducting ZnCNi{sub 3}. The optimized structural parameters were determined using different exchange-correlation potentials. The calculated lattice constants are within the usual accuracy range of such calculations although the deviations of results obtained using the generalized gradient approximation proposed by Wu-Cohen(WC-GGA) are the least. The independent elastic constants (C{sub 11}, C{sub 12}and C{sub 44}) are evaluated and numerical estimates of elastic parameters of the polycrystalline compounds were obtained in the framework of the Voigt-Reuss-Hill approximations. These elastic parameters, some of which are found to be of comparable magnitude in both compounds, were used to examine their mechanical properties. We found that the materials are brittle and with fairly high elastic anisotropy. The electronic band structures, total, site and orbital decomposed densities of states (DOS) were obtained and analysed. Our electronic structure results show that in ZnNNi{sub 3}, states near the Fermi energy are dominated by Ni d and N p states. This is also the case for ZnCNi{sub 3}. The peak in the DOS due to Ni d{sub xz},d{sub yz} in ZnNNi{sub 3} is closest to the Fermi energy, and is about 0.21 eV away from the Fermi energy compared with an energy distance of 0.09 eV away of similar peak in ZnCNi{sub 3}, resulting in decreased value of Fermi level density of states in ZnNNi{sub 3}. We estimated the Debye temperature of both compounds from the calculated mean sound velocity. Our results show that the stoichiometric ZnNNi{sub 3} and ZnCNi{sub 3} are very much alike in

  8. Topographical variation of the elastic properties of articular cartilage in the canine knee.

    Science.gov (United States)

    Jurvelin, J S; Arokoski, J P; Hunziker, E B; Helminen, H J

    2000-06-01

    Equilibrium response of articular cartilage to indentation loading is controlled by the thickness (h) and elastic properties (shear modulus, mu, and Poisson's ratio, nu) of the tissue. In this study, we characterized topographical variation of Poisson's ratio of the articular cartilage in the canine knee joint (N=6). Poisson's ratio was measured using a microscopic technique. In this technique, the shape change of the cartilage disk was visualized while the cartilage was immersed in physiological solution and compressed in unconfined geometry. After a constant 5% axial strain, the lateral strain was measured during stress relaxation. At equilibrium, the lateral-to-axial strain ratio indicates the Poisson's ratio of the tissue. Indentation (equilibrium) data from our prior study (Arokoski et al., 1994. International Journal of Sports Medicine 15, 254-260) was re-analyzed using the Poisson's ratio results at the test site to derive values for shear and aggregate moduli. The lowest Poisson's ratio (0.070+/-0.016) located at the patellar surface of femur (FPI) and the highest (0.236+/-0.026) at the medial tibial plateau (TMI). The stiffest cartilage was found at the patellar groove of femur (micro=0.964+/-0.189MPa, H(a)=2.084+/-0. 409MPa) and the softest at the tibial plateaus (micro=0.385+/-0. 062MPa, H(a)=1.113+/-0.141MPa). Comparison of the mechanical results and the biochemical composition of the tissue (Jurvelin et al., 1988. Engineering in Medicine 17, 157-162) at the matched sites of the canine knee joint indicated a negative correlation between the Poisson's ratio and collagen-to-PG content ratio. This is in harmony with our previous findings which suggested that, in unconfined compression, the degree of lateral expansion in different tissue zones is related to collagen-to-PG ratio of the zone.

  9. Quantification of effects of cancer on elastic properties of breast tissue by Atomic Force Microscopy.

    Science.gov (United States)

    Ansardamavandi, Arian; Tafazzoli-Shadpour, Mohammad; Omidvar, Ramin; Jahanzad, Iisa

    2016-07-01

    Different behaviors of cells such as growth, differentiation and apoptosis widely differ in case of diseases. The mechanical properties of cells and tissues can be used as a clue for diagnosis of pathological conditions. Here, we implemented Atomic Force Microscopy to evaluate the extent of alteration in mechanical stiffness of tissue layers from patients affected by breast cancer and investigated how data can be categorized based on pathological observations. To avoid predefined categories, Fuzzy-logic algorithm as a novel method was used to divide and categorize the derived Young׳s modulus coefficients (E). Such algorithm divides data among groups in such way that data of each group are mostly similar while dissimilar with other groups. The algorithm was run for different number of categories. Results showed that three (followed by two with small difference) groups categorized data best. Three categories were defined as (E7000Pa) among which data were allocated. The first cluster was assumed as the cellular region while the last cluster was referred to the fibrous parts of the tissue. The intermediate region was due to other non-cellular parts. Results indicated 50% decline of average Young׳s modulus of cellular region of cancerous tissues compared to healthy tissues. The average Young׳s modulus of non-cellular area of normal tissues was slightly lower than that of cancerous tissues, although the difference was not statistically different. Through clustering, the measured Young׳s moduli of different locations of cancerous tissues, a quantified approach was developed to analyze changes in elastic modulus of a spectrum of components of breast tissue which can be applied in diagnostic mechanisms of cancer development, since in cancer progression the softening cell body facilitates the migration of cancerous cells through the original tumor and endothelial junctions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. First-principles study of the structural and elastic properties of rhenium-based transition-metal alloys

    Science.gov (United States)

    de Jong, Maarten; Olmsted, David L.; van de Walle, Axel; Asta, Mark

    2012-12-01

    Structural, energetic, and elastic properties of hexagonal-close-packed rhenium-based transition-metal alloys are computed by density-functional theory. The practical interest in these materials stems from the attractive combination of mechanical properties displayed by rhenium for structural applications requiring the combination of high melting temperature and low-temperature ductility. Single-crystal elastic constants, atomic volumes, axial c/a ratios, and dilute heats of solution for Re-X alloys are computed, considering all possible transition-metal solute species X. Calculated elastic constants are used to compute values of a commonly considered intrinsic-ductility parameter K/G, where K is the bulk modulus and G denotes the Voigt average of the shear modulus, as well as the anisotropies in the Young's modulus and shear modulus. The calculated properties show clear trends as a function of d-band filling, which can be rationalized through tight-binding theory. The results indicate that solutes to the left of rhenium in the periodic table show a tendency to increase the intrinsic ductility parameter, a trend that correlates with an increase of the c/a ratio towards the ideal value associated optimal close packing. The Young's modulus shows a trend towards increasing isotropy with alloying of solutes X to the left of Re, while the shear modulus shows the opposite trend but with an overall weaker dependence on solute additions.

  11. Numerical Estimation of the Elastic Properties of Thin-Walled Structures Manufactured from Short-Fiber-Reinforced Thermoplastics

    Science.gov (United States)

    Altenbach, H.; Naumenko, K.; L'vov, G. I.; Pilipenko, S. N.

    2003-05-01

    A model which allows us to estimate the elastic properties of thin-walled structures manufactured by injection molding is presented. The starting step is the numerical prediction of the microstructure of a short-fiber-reinforced composite developed during the filling stage of the manufacturing process. For this purpose, the Moldflow Plastic Insight® commercial program is used. As a result of simulating the filling process, a second-rank orientation tensor characterizing the microstructure of the material is obtained. The elastic properties of the prepared material locally depend on the orientational distribution of fibers. The constitutive equation is formulated by means of orientational averaging for a given orientation tensor. The tensor of elastic material properties is computed and translated into the format for a stress-strain analysis based on the ANSYSÒ finite-element code. The numerical procedure and the convergence of results are discussed for a thin strip, a rectangular plate, and a shell of revolution. The influence of manufacturing conditions on the stress-strain state of statically loaded thin-walled elements is illustrated.

  12. Effect of water content on the structural reorganization and elastic properties of biopolymer films: a comparative study.

    Science.gov (United States)

    Yakimets, Iryna; Paes, Sabrina S; Wellner, Nikolaus; Smith, Andrew C; Wilson, Reginald H; Mitchell, John R

    2007-05-01

    In this work, the effect of water uptake on the structural reorganization and elastic properties of three types of biopolymer films was studied. The water-biopolymer interaction for hydroxypropyl cellulose (HPC), gelatin, and cassava starch films prepared from aqueous solutions was studied and compared using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction, dynamic vapor sorption (DVS), and dynamic mechanical thermal analysis with humidity generator and controller (DMTA) techniques. The FTIR spectral variations due to the water sorption were generalized into two-dimensional (2D) correlation graphs for each biopolymer, and the effect of water on the molecular conformation was compared. The water sorption isotherms were fitted with Guggenheim-Anderson-De Boer (GAB) and D'Arcy and Watt models. The water content in the mono- and multilayers predicted by both models for each biopolymer was discussed and compared. The correlation of the fitted data obtained from the sorption isotherms to the DMTA data allowed us to conclude that the elastic properties of the HPC films depended on the total water content in contrast to the elastic properties of the gelatin and cassava starch films, which decrease only with the appearance of multilayer water.

  13. Phase transition, elastic and electronic properties of topological insulator Sb2Te3 under pressure: First principle study

    Science.gov (United States)

    Qing, Lu; Huai-Yong, Zhang; Yan, Cheng; Xiang-Rong, Chen; Guang-Fu, Ji

    2016-02-01

    The phase transition, elastic and electronic properties of three phases (phase I, II, and III) of Sb2Te3 are investigated by using the generalized gradient approximation (GGA) with the PBESOL exchange-correlation functional in the framework of density-functional theory. Some basic physical parameters, such as lattice constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, acoustic velocity, and Debye temperature Θ are calculated. The obtained lattice parameters under various pressures are consistent with experimental data. Phase transition pressures are 9.4 GPa (I → II) and 14.1 GPa (II → III), which are in agreement with the experimental results. According to calculated elastic constants, we also discuss the ductile or brittle characters and elastic anisotropies of three phases. Phases I and III are brittle, while phase II is ductile. Of the three phases, phase II has the most serious degree of elastic anisotropy and phase III has the slightest one. Finally, we investigate the partial densities of states (PDOSs) of three phases and find that the three phases possess some covalent features. Project supported by the National Natural Science Foundation of China (Grant Nos. 11204192 and 11174214) and Jointly supported by the National Natural Science Foundation of China and the China Academy of Engineering Physics (NSAF) (Grant No. U1430117).

  14. An Atomistic-Based Continuum Modeling for Evaluation of Effective Elastic Properties of Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    M. S. M. Al-Kharusi

    2016-01-01

    Full Text Available The mechanical behavior of SWCNTs is characterized using an atomistic-based continuum method. At nanoscale, interatomic energy among carbon atoms and the corresponding force constants are defined. Subsequently, we used an atomistic finite element analysis to calculate the energy stored in the SWCNT model, which forms a basis for calculating effective elastic moduli. In the finite element model, the force interaction among carbon atoms in a SWCNT is modeled using load-carrying structural beams. At macroscale, the SWCNT is taken as cylindrical continuum solid with transversely isotropic mechanical properties. Equivalence of energies of both models establishes a framework to calculate effective elastic moduli of armchair and zigzag nanotubes. This is achieved by solving five boundary value problems under distinct essential-controlled boundary conditions, which generates a prescribed uniform strain field in both models. Elastic constants are extracted from the calculated elastic moduli. While results of Young’s modulus obtained in this study generally concur with the published theoretical and numerical predictions, values of Poisson’s ratio are on the high side.

  15. Measurements of Elastic and Inelastic Properties of Polycrystalline Samples under Simulated Earth's Mantle Conditions in Large Volume Apparatus

    Science.gov (United States)

    Mueller, Hans J.

    2017-04-01

    The interpretation of highly resolved seismic data from Earth=s deep interior require measurements of the physical properties of Earth's materials under experimental simulated mantle conditions. More than a decade ago seismic tomography clearly showed subduction of crustal material can reach the core mantle boundary under specific circumstances. Considering this geophysical high pressure research is faced the challenge to increase pressure and sample volume at the same time to be able to perform in situ experiments with geophysical representative complex samples. Recent large volume presses at synchrotrons provide sample volumes 3 to 7 orders of magnitude bigger than in diamond anvil cells far beyond transition zone conditions. The sample size of several cubic millimeters allows elastic wave frequencies in the low to medium MHz range. Together with the small and even adjustable temperature gradients over the whole sample this technique makes anisotropy and grain boundary effects in complex systems accessible for elastic and inelastic properties measurements in principle. The real elastic wave propagation have also no limits for opaque and encapsulated samples. Using triple-mode transducers and the data transfer function technique for ultrasonic interferometry makes transient measurements in complex systems under non-equilibrium conditions possible. Ultrasonic interferometry necessarily requires in situ sample deformation measurement by X-radiography. In situ falling sphere viscosimetry require time-resolved X-radiography. Using a D-DIA even the measurement of elastic and inelastic properties in the seismic frequency range is achievable. The paper presents techniques and results of recent experimental high pressure geophysics in LVPs.

  16. Monitoring the temperature-dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy

    Directory of Open Access Journals (Sweden)

    M. J. Vaughan

    2016-11-01

    calibration of active and passive seismic data gathered in the field. The elastic properties and anelastic quality factor Q in laboratory-manufactured polycrystalline isotropic ice cores decrease (reversibly with increasing temperature, but compressional-wave speed and attenuation prove most sensitive to temperature, indicative of pre-melting of the ice. This method of resonant ultrasound spectroscopy can be deployed in the field, for those situations where shipping samples is difficult (e.g. remote locations, or where the properties of ice change rapidly after extraction (e.g. in the case of sea ice.

  17. First-principles calculations of structural, elastic, electronic and optical properties of the antiperovskite AsNMg{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Bouhemadou, A. [Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria)], E-mail: a_bouhemadou@yahoo.fr; Khenata, R. [Department of Physics, University of Mascara, 29000 Mascara (Algeria); Chegaar, M.; Maabed, S. [Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria)

    2007-11-19

    The density functional theory (DFT) calculations of structural, elastic, electronic and optical properties of the cubic antiperovskite AsNMg{sub 3} has been reported using the pseudo-potential plane wave method (PP-PW) within the generalized gradient approximation (GGA). The equilibrium lattice, bulk modulus and its pressure derivative have been determined. The elastic constants and their pressure dependence are calculated using the static finite strain technique. We derived the bulk and shear moduli, Young's modulus and Poisson's ratio for ideal polycrystalline AsNMg{sub 3} aggregate. We estimated the Debye temperature of AsNMg{sub 3} from the average sound velocity. This is the first quantitative theoretical prediction of the elastic properties of AsNMg{sub 3} compound, and it still awaits experimental confirmation. Band structure, density of states and pressure coefficients of energy gaps are also given. The fundamental band gap ({gamma}-{gamma}) initially increases up to 4 GPa and then decreases as a function of pressure. Furthermore, the dielectric function, optical reflectivity, refractive index, extinction coefficient, and electron energy loss are calculated for radiation up to 30 eV. The all results are compared with the available theoretical and experimental data.

  18. The role of water in the elastic properties of aluminosilicate zeolites: DFT investigation.

    Science.gov (United States)

    Bryukhanov, Ilya A; Rybakov, Andrey A; Larin, Alexander V; Trubnikov, Dmitry N; Vercauteren, Daniel P

    2017-03-01

    The bulk and Young moduli and heats of hydration have been calculated at the DFT level for fully optimized models of all-siliceous and cationic zeolites with and without water, and then compared to the corresponding experimental data. Upon the addition of water, the monovalent alkali ion and divalent alkaline earth ion exchanged zeolites presented opposite trends in the elastic modulus. The main contribution to the decrease in the elastic modulus of the alkali ion exchanged zeolites appeared to be a shift of cations from the framework oxygen atoms upon water addition, with the coordination number often remaining the same. The contrasting increase in elastic modulus observed for the divalent (alkaline earth) ion exchanged zeolites was explained by cation stabilization resulting from increased coordination, which cannot be achieved within a rigid zeolite framework without water.

  19. Physical properties of sand from the waste water treatment plants

    Directory of Open Access Journals (Sweden)

    Tomáš Vítěz

    2010-01-01

    Full Text Available The work is focused on characterization of selected physical properties of sewage sand from the waste water treatment plants. Sand is transported into wastewater mainly in areas with a combined se­we­ra­ge system – principally in connection with rainfalls, in case of which it is transported through the sewerage system together with rainwater, but also (within smaller extents due to leakages of sewerage systems or bad conduct of natural persons and legal entities. The main attention was focused on basic physical parameters such as content of total solid, ash free dry mass, density and granulometry. These material parameters are very often underestimated so the set of quality data is completly missing, as well as a background for designers of wastewater treatment plants. This paper should be quite useful e.g. for the purpose of technological equipment design in the region of South Moravia.

  20. A GENERALIZED CROSS-PROPERTY RELATION BETWEEN THE ELASTIC MODULI AND CONDUCTIVITY OF ISOTROPIC POROUS MATERIALS WITH SPHEROIDAL PORES

    Directory of Open Access Journals (Sweden)

    Willi Pabst

    2016-12-01

    Full Text Available A new generalized cross-property relation is proposed for predicting the relative elastic moduli (Young's modulus, shear modulus, bulk modulus from the relative conductivities (thermal or electrical of isotropic porous materials with spheroidal pores. Using this cross-property-relation it is possible to estimate the elastic moduli when the conductivites are known (either from real-world measurements or from numerical calculations on digital microstructures and vice versa. This generalized cross-property relation contains the case of spherical or isometric pores as a special case, but is sufficiently general to account for the properties of materials with strongly anisometric pores, i.e. randomly orientated prolate and oblate pores, including the extreme cases of pore channels or microcracks. The exponent of this cross-property relation is shown in graphical form and - for future reference with respect to practical applications - its numerical values are listed in tabular form as a function of the pore aspect ratio and the Poisson ratio of the solid

  1. Role of Vacancies on Electronic and Elastic Properties of RuAl2 Semiconducting Compound from First-Principles Calculations

    Science.gov (United States)

    Pan, Yong; Jin, Chao; Mao, Pengyu

    2017-11-01

    RuAl2 is a fascinating intermetallic semiconducting compound. However, the influence of vacancies on the electronic and mechanical properties of RuAl2 is unknown. By means of first-principles calculations, we have investigated the influence of vacancies on the electronic properties, elastic modulus, brittle or ductile behavior and Vickers hardness of RuAl2. Two possible vacancy types, Ru-va and Al-va, are considered. The calculated results show that the Ru-va vacancy is more thermodynamically stable than that of the Al-va vacancy. Importantly, we find that vacancies can improve the electronic properties of RuAl2 because the removed Ru or Al atom enhances the charge overlap between conduction band and the valence band near the Fermi level. In addition, these vacancies weaken the resistance to volume deformation, shear deformation and the elastic stiffness of RuAl2 because the removed atom weakens the localized hybridization between the Ru atom and the Al atom. However, the Ru-va vacancy can improve the Vickers hardness and Al-va vacancies result in brittle-to-ductile transition of RuAl2. The variation of mechanical properties is attributed to the Ru-Al and Al-Al metallic bonds along the shear direction. Therefore, we can conclude that vacances are beneficial for improving the electronic and mechanical properties of RuAl2.

  2. Geotechnical properties of municipal solid waste at Laogang Landfill, China.

    Science.gov (United States)

    Feng, Shi-Jin; Gao, Ke-Wei; Chen, Yi-Xin; Li, Yao; Zhang, L M; Chen, H X

    2017-05-01

    Landfills have been widely constructed all around the world in order to properly dispose municipal solid waste (MSW). Understanding geotechnical properties of MSW is essential for the design and operation of landfills. A comprehensive investigation of geotechnical properties of MSW at the largest landfill in China was conducted, including waste composition, unit weight, void ratio, water content, hydraulic conductivity, and shear behavior. A large-scale rigid-wall permeameter and a direct-shear apparatus were adopted to test the hydraulic conductivity and shear behavior of the MSW, respectively. The composition of the MSW varied with age. With the depth increasing from 0 to 16m, the unit weight increased from 7.2 to 12.5kN/m(3), while the void ratio decreased from 2.5 to 1.76. The water content ranged between 30.0% and 68.9% but did not show a trend with depth. The hydraulic conductivity of the MSW ranged between 4.6×10(-4) and 6.7×10(-3)cm/s. It decreased as the dry unit weight increased and was sensitive to changes in dry unit weight in deeper layers. Displacement-hardening was observed during the whole shearing process and the shear strength increased with the normal stress, the displacement rate, and the unit weight. The friction angle and cohesion varied from (15.7°, 29.1kPa) to (21.9°, 18.3kPa) with depth increasing from 4 to 16m. The shear strength of the MSW obtained in this study was lower than the reported values in other countries, which was caused by the less fibrous materials in the specimens in this study. The results in this study will provide guidance in the design and operation of the landfills in China. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of van der Waals interactions on the structural and elastic properties of black phosphorus

    DEFF Research Database (Denmark)

    Appalakondaiah, S.; Vaitheeswaran, G.; Lebègue, S.

    2012-01-01

    (GGA), and with several dispersion corrections to include van der Waals interactions. It is found that the dispersion corrections improve the lattice parameters over LDA and GGA in comparison with experimental results. The calculations reproduce well the experimental trends under pressure and show...... that van der Waals interactions are most important for the crystallographic b axis in the sense that they have the largest effect on the bonding between the phosphorus layers. The elastic constants are calculated and are found to be in good agreement with experimental values. The calculated C22 elastic...

  4. First-principles investigation of structural, elastic, lattice dynamical and thermodynamic properties of lithium sulfur under pressure

    Science.gov (United States)

    Saib, S.; Bouarissa, N.

    2017-10-01

    In this study we report on the influence of hydrostatic pressure on structural, elastic, lattice dynamical and thermal properties of Li2S in the anti-fluorite structure using ab initio pseudopotential approach based on the density functional perturbation theory. Our results are found to be in good agreement with those existing in the literature. The present phonon dispersion spectra, dielectric constants and Born effective charges may be seen as the first investigation for the material under load. The pressure dependence of all features of interest has been examined and discussed. Besides, the temperature dependence of the lattice parameter and bulk modulus is predicted. The generalized elastic stability criteria showed that the material of interest is mechanically unstable for pressures beyond 55 GPa.

  5. Theory-Guided Materials Design of Multi-Phase Ti-Nb Alloys with Bone-Matching Elastic Properties

    Directory of Open Access Journals (Sweden)

    Jörg Neugebauer

    2012-10-01

    Full Text Available We present a scale-bridging approach for modeling the integral elasticresponse of polycrystalline composite that is based on a multi-disciplinary combination of(i parameter-free first-principles calculations of thermodynamic phase stability andsingle-crystal elastic stiffness; and (ii homogenization schemes developed forpolycrystalline aggregates and composites. The modeling is used as a theory-guidedbottom-up materials design strategy and applied to Ti-Nb alloys as promising candidatesfor biomedical implant applications. The theoretical results (i show an excellent agreementwith experimental data and (ii reveal a decisive influence of the multi-phase character ofthe polycrystalline composites on their integral elastic properties. The study shows thatthe results based on the density functional theory calculations at the atomistic level canbe directly used for predictions at the macroscopic scale, effectively scale-jumping severalorders of magnitude without using any empirical parameters.

  6. Synthesis, electronic structure, elastic properties, and interfacial behavior of icosahedral boron-rich solids

    Energy Technology Data Exchange (ETDEWEB)

    Hunold, Oliver

    2017-08-01

    relationship of icosahedral B-rich solids as weil as comprise important aspects for applications, such as the influence of impurity incorporations on the elastic properties, the formation of competing phases during synthesis, and the effect of atmosphere exposure on the interaction with a workpiece.

  7. Pair collisions of fluid-filled elastic capsules in shear flow: Effects of membrane properties and polymer additives

    Science.gov (United States)

    Pranay, Pratik; Anekal, Samartha G.; Hernandez-Ortiz, Juan P.; Graham, Michael D.

    2010-12-01

    The dynamics and pair collisions of fluid-filled elastic capsules during Couette flow in Newtonian fluids and dilute solutions of high-molecular weight (drag-reducing) polymers are investigated via direct simulation. Capsule membranes are modeled using either a neo-Hookean constitutive model or a model introduced by Skalak et al. ["Strain energy function of red blood-cell membranes," Biophys. J. 13, 245 (1973)], which includes an energy penalty for area changes. This model was developed to capture the elastic properties of red blood cells. Polymer molecules are modeled as bead-spring trimers with finitely extensible nonlinearly elastic springs; parameters were chosen to loosely approximate 4000 kDa poly(ethylene oxide). Simulations are performed with a novel Stokes flow formulation of the immersed boundary method for the capsules, combined with Brownian dynamics for the polymer molecules. The results for isolated capsules in shear indicate that at the very low concentrations considered here, polymers have a little effect on the capsule shape. In the case of pair collisions, the effect of polymer is strongly dependent on the elastic properties of the capsules' membranes. For neo-Hookean capsules or for Skalak capsules with only a small penalty for area change, the net displacement in the gradient direction after collision is virtually unaffected by the polymer. For Skalak capsules with a large penalty for area change, polymers substantially decrease the net displacement when compared to the Newtonian case and the effect is enhanced upon increasing the polymer concentration. The differences between the polymer effects in the various cases are associated with the extensional flow generated in the region between the capsules as they leave the collision. The extension rate is highest when there is a strong resistance to a change in the membrane area and is substantially decreased in the presence of polymer.

  8. The effects of gamma irradiation on the elastic properties of soda lime glass doped with cerium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Laopaiboon, R.; Laopaiboon, J.; Pencharee, S. [Glass Technology Excellent Center (GTEC), Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand); Nontachat, S. [Department of Radiotherapy, Ubon Ratchathani Cancer Centre, Ubon Ratchathani, 34190 (Thailand); Bootjomchai, C., E-mail: cherdsak_per@hotmail.co.th [Glass Technology Excellent Center (GTEC), Department of Physics, Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani, 34190 (Thailand)

    2016-05-05

    Soda lime glass doped with cerium oxide was prepared using a conventional melt quenching technique. The density and molar volume of the glass samples were measured. Ultrasonic wave velocities of the glass samples were carried out using a pulse echo technique. The density and ultrasonic velocities were used for determining elastic moduli of the glass samples, both before and after irradiation with gamma rays at 1 kGy. The results revealed that the influence of gamma irradiation caused the matrix structure of the glass samples to be damaged by creating displacements, electronic defects and/or breaks in the network bonds, leading to the formation of non-bridging oxygens (NBOs). Elastic properties were investigated under the influence of gamma irradiation. The results also revealed that the structures of the glass samples were distorted by irradiation. Damage by irradiation created the NBOs and/or the transformation of main glass network structures from Q{sub 4} to Q{sub 3}. Evidence of these results was acquired from FTIR spectra. The results of FTIR supported the results and were obtained from ultrasonic velocities. In addition, the elastic properties obtained from experiments were compared with theoretical values calculated from the Makishima and Mackenzie model (M–M model). - Highlights: • Results show good agreement between experimental and theoretical of elastic moduli. • Influence of irradiation created a distorted network structure. • Transformation of network structure from Ref. Q{sub 4} to Q{sub 3} after irradiation. • FTIR result is good evidence of the result is obtained from ultrasonic technique.

  9. Al{sub 4}SiC{sub 4} wurtzite crystal: Structural, optoelectronic, elastic, and piezoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Pedesseau, L., E-mail: laurent.pedesseau@insa-rennes.fr, E-mail: jacky.even@insa-rennes.fr; Even, J., E-mail: laurent.pedesseau@insa-rennes.fr, E-mail: jacky.even@insa-rennes.fr; Durand, O. [Fonctions Optiques pour les Technologies de l’Information, FOTON UMR 6082, CNRS, INSA de Rennes, 35708 Rennes (France); Modreanu, M. [Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland); Chaussende, D.; Sarigiannidou, E.; Chaix-Pluchery, O. [LMGP, CNRS, Université Grenoble Alpes, 38000 Grenoble (France)

    2015-12-01

    New experimental results supported by theoretical analyses are proposed for aluminum silicon carbide (Al{sub 4}SiC{sub 4}). A state of the art implementation of the density functional theory is used to analyze the experimental crystal structure, the Born charges, the elastic properties, and the piezoelectric properties. The Born charge tensor is correlated to the local bonding environment for each atom. The electronic band structure is computed including self-consistent many-body corrections. Al{sub 4}SiC{sub 4} material properties are compared to other wide band gap wurtzite materials. From a comparison between an ellipsometry study of the optical properties and theoretical results, we conclude that the Al{sub 4}SiC{sub 4} material has indirect and direct band gap energies of about 2.5 eV and 3.2 eV, respectively.

  10. A nonlinear theory for elastic plates with application to characterizing paper properties

    Science.gov (United States)

    M. W. Johnson; Thomas J. Urbanik

    1984-03-01

    A theory of thin plates which is physically as well as kinematically nonlinear is, developed and used to characterize elastic material behavior for arbitrary stretching and bending deformations. It is developed from a few clearly defined assumptions and uses a unique treatment of strain energy. An effective strain concept is introduced to simplify the theory to a...

  11. Change of Static and Dynamic Elastic Properties due to CO² Injection in North Sea Chalk

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Hjuler, M.L.; Christensen, H.F.

    2012-01-01

    . We observed lower dynamic elastic modulus for chalk with higher non-carbonate content at porosities lower than 30%. In 30% porosity chalk, dynamic compressional and bulk modulus were found significantly higher than the static modulus. Static measurements with LVDT were found lowest. The effect of CO2...

  12. Elastic and viscoelastic mechanical properties of brain tissues on the implanting trajectory of sub-thalamic nucleus stimulation.

    Science.gov (United States)

    Li, Yan; Deng, Jianxin; Zhou, Jun; Li, Xueen

    2016-11-01

    Corresponding to pre-puncture and post-puncture insertion, elastic and viscoelastic mechanical properties of brain tissues on the implanting trajectory of sub-thalamic nucleus stimulation are investigated, respectively. Elastic mechanical properties in pre-puncture are investigated through pre-puncture needle insertion experiments using whole porcine brains. A linear polynomial and a second order polynomial are fitted to the average insertion force in pre-puncture. The Young's modulus in pre-puncture is calculated from the slope of the two fittings. Viscoelastic mechanical properties of brain tissues in post-puncture insertion are investigated through indentation stress relaxation tests for six interested regions along a planned trajectory. A linear viscoelastic model with a Prony series approximation is fitted to the average load trace of each region using Boltzmann hereditary integral. Shear relaxation moduli of each region are calculated using the parameters of the Prony series approximation. The results show that, in pre-puncture insertion, needle force almost increases linearly with needle displacement. Both fitting lines can perfectly fit the average insertion force. The Young's moduli calculated from the slope of the two fittings are worthy of trust to model linearly or nonlinearly instantaneous elastic responses of brain tissues, respectively. In post-puncture insertion, both region and time significantly affect the viscoelastic behaviors. Six tested regions can be classified into three categories in stiffness. Shear relaxation moduli decay dramatically in short time scales but equilibrium is never truly achieved. The regional and temporal viscoelastic mechanical properties in post-puncture insertion are valuable for guiding probe insertion into each region on the implanting trajectory.

  13. Determination of elastic and thermal properties of a thin nanocrystalline diamond coating using all-optical methods

    Energy Technology Data Exchange (ETDEWEB)

    Sermeus, J.; Verstraeten, B.; Salenbien, R. [KU Leuven-University of Leuven, Soft Matter and Biophysics, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Pobedinskas, P.; Haenen, K. [Instituut voor Materiaalonderzoek (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek (Belgium); IMOMEC, IMEC vzw, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Glorieux, C., E-mail: christ.glorieux@fys.kuleuven.be [KU Leuven-University of Leuven, Soft Matter and Biophysics, Celestijnenlaan 200D, B-3001 Heverlee (Belgium)

    2015-09-01

    Results are presented on the thermal and elastic properties of a thin, 1.5 μm, nanocrystalline diamond coating (NCD), deposited on a silicon substrate by microwave plasma enhanced chemical vapor deposition. A combination of two all-optical measurement techniques, impulsive stimulated thermal scattering and grating induced laser beam deflection, was employed to launch and detect surface acoustic waves (SAWs). The relation between the dispersive propagation velocity of SAWs to the coating-substrate geometry is exploited to determine the elastic properties of the NCD coating. The elastic properties are found to be consistent with literature values. The thermal properties of the coating were determined by monitoring the thermal diffusion induced washing away of the laser induced transient surface temperature grating. The transient thermal grating signals were fitted by the low-frequency limit of a thermoelastic model for a multilayer configuration. Similar to the dispersion of the surface acoustic wave velocity, the characteristic time of the thermal diffusion driven grating decay evolves from a coating-dominated value at short grating spacings towards a substrate-dominated value at grating spacings well exceeding the coating thickness. The grating spacing dependence of the corresponding effective thermal diffusivity was experimentally determined and fitted, leading to a value for the thermal diffusivity of the NCD coating α{sub NCD} = 8.4{sub −0.1}{sup +2.7} mm{sup 2}·s{sup −1}, which is an order of magnitude lower than that of the silicon substrate. The low value of the thermal diffusivity is interpreted with a simple touching model. - Highlights: • We investigate a thin nano-crystalline diamond coating. • We used two all optical surface acoustic wave based methods. • We found a young's modulus and density that is in line with literature. • The thermal diffusivity of the NCD coating was 2 orders of magnitude lower than the one of bulk diamond.

  14. Elastic and thermal properties of free-standing molybdenum disulfide membranes measured using ultrafast transient grating spectroscopy

    Science.gov (United States)

    Kim, Taeyong; Ding, Ding; Yim, Jong-Hyuk; Jho, Young-Dahl; Minnich, Austin J.

    2017-08-01

    Molybdenum disulfide (MoS2), a member of transition-metal dichalcogenide family, is of intense interest due to its unique electronic and thermoelectric properties. However, reports of its in-plane thermal conductivity vary due to the difficulty of in-plane thermal conductivity measurements on thin films, and an experimental measurement of the in-plane sound velocity has not been reported. Here, we use time-resolved transient grating spectroscopy to simultaneously measure the in-plane elastic and thermal properties of free-standing MoS2 membranes at room temperature. We obtain a longitudinal acoustic phonon velocity of 7000 ± 40 m s-1 and an in-plane thermal conductivity of 74 ± 21 W m-1K-1. Our measurements provide useful insights into the elastic and thermal properties of MoS2 and demonstrate the capability of transient grating spectroscopy to investigate the in-plane vibrational properties of van der Waals materials that are challenging to characterize with conventional methods.

  15. Elastic and thermal properties of free-standing molybdenum disulfide membranes measured using ultrafast transient grating spectroscopy

    Directory of Open Access Journals (Sweden)

    Taeyong Kim

    2017-08-01

    Full Text Available Molybdenum disulfide (MoS2, a member of transition-metal dichalcogenide family, is of intense interest due to its unique electronic and thermoelectric properties. However, reports of its in-plane thermal conductivity vary due to the difficulty of in-plane thermal conductivity measurements on thin films, and an experimental measurement of the in-plane sound velocity has not been reported. Here, we use time-resolved transient grating spectroscopy to simultaneously measure the in-plane elastic and thermal properties of free-standing MoS2 membranes at room temperature. We obtain a longitudinal acoustic phonon velocity of 7000 ± 40 m s−1 and an in-plane thermal conductivity of 74 ± 21 W m−1K−1. Our measurements provide useful insights into the elastic and thermal properties of MoS2 and demonstrate the capability of transient grating spectroscopy to investigate the in-plane vibrational properties of van der Waals materials that are challenging to characterize with conventional methods.

  16. Stability and Elastic, Electronic, and Thermodynamic Properties of Fe2TiSi1- x Sn x Compounds

    Science.gov (United States)

    Jong, Ju-Yong; Yan, Jihong; Zhu, Jingchuan; Kim, Chol-Jin

    2017-10-01

    We have systematically studied the structural, phase, and mechanical stability and elastic, electronic, and thermodynamic properties of Fe2TiSi1- x Sn x ( x = 0, 0.25, 0.5, 0.75, 1) compounds using first-principles calculations. The structural and phase stability and elastic properties of Fe2TiSi1- x Sn x ( x = 0, 0.25, 0.5, 0.75, 1) indicated that all of the compounds are thermodynamically and mechanically stable. The shear modulus, bulk modulus, Young's modulus, Poisson's ratio, electronic band structure, density of states, Debye temperature, and Grüneisen parameter of all the substituted compounds were studied. The results show that Sn substitution in Fe2TiSi enhances its stability and mechanical and thermoelectric properties. The Fe2TiSi1- x Sn x compounds have narrow bandgap from 0.144 eV and 0.472 eV for Sn substitution from 0 to 1. The calculated band structure and density of states (DOS) of Fe2TiSi1- x Sn x show that the thermoelectric properties can be improved at substituent concentration x of 0.75. The lattice thermal conductivity was significantly decreased in the Sn-substituted compounds, and all the results indicate that Fe2TiSi0.25Sn0.75 could be a new candidate high-performance thermoelectric material.

  17. First-principles prediction of structural, elastic, electronic and thermodynamic properties of the cubic SrUO{sub 3}-Perovskite

    Energy Technology Data Exchange (ETDEWEB)

    Sahli, B. [Laboratoire de Génie Physique, Université Ibn Khaldoun, Tiaret, 14000 (Algeria); Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria); Bouafia, H., E-mail: hamza.tssm@gmail.com [Laboratoire de Génie Physique, Université Ibn Khaldoun, Tiaret, 14000 (Algeria); Abidri, B.; Abdellaoui, A. [Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria); Hiadsi, S.; Akriche, A. [Laboratoire de Microscope Electronique et Sciences des Matériaux, Université des Sciences et de la Technologie Mohamed Boudiaf, département de Génie Physique, BP1505 El m’naouar, Oran (Algeria); Benkhettou, N.; Rached, D. [Laboratoire des Matériaux Magnétiques, Université Djillali Liabés, Sidi Bel-Abbes 22000 (Algeria)

    2015-06-25

    Highlights: • The ground state properties of SrUO{sub 3}-Perovskite were investigated. • Elastic constants and their related parameters were calculated. • Electronic properties are treated using GGA-PBEsol + U approach. - Abstract: In this paper, we investigate bulk properties of the cubic SrUO{sub 3}-Perovskite in their nonmagnetic (NM), antiferromagnetic (AFM) and ferromagnetic (FM) states using all-electron self consistent Full Potential Augmented Plane Waves plus local orbital (FP-(L)APW + lo) method within PBEsol Generalized Gradiant density approximations. Our calculation allowed us to predict that the more stable magnetic state of the cubic SrUO{sub 3}-Perovskite is that of the ferromagnetic (FM). This work is the first prediction of elastic constants and their related parameters (Young modulus, shear modulus, Poisson ratio, Zener anisotropy and the Debye temperature) for this cubic compound using Mehl method. We have employed the GGA(PBEsol) and GGA(PBEsol) + U to investigate the electronic band structure, density of states and electronic charge density of SrUO{sub 3}-Perovskite. The electronic band structure calculations revealed that SrUO{sub 3} exhibits metallic behavior. On the other hand the charge density plots for [1 1 0] direction indicates a strong ionic character along the Sr–O bond while the U–O bond has strong covalent character. Finally, we have analyzed the thermodynamic properties using the quasi-harmonic Debye model to complete the fundamental characterization of cubic SrUO{sub 3}-Perovskite.

  18. Engineering properties of fibres from waste fishing nets

    DEFF Research Database (Denmark)

    Bertelsen, Ida Maria Gieysztor; Ottosen, Lisbeth M.

    2016-01-01

    This study is part of the international project Circular Ocean and focuses on reducing marine plastic waste within the Northern Periphery and Arctic (NPA) region by developing new sustainable solutions for the reuse of discarded waste fishing nets. Recycled plastic fibres from waste fishing nets...

  19. The nonlinear elastic and viscoelastic passive properties of left ventricular papillary muscle of a guinea pig heart.

    Science.gov (United States)

    Hassan, M A; Hamdi, M; Noma, A

    2012-01-01

    The mechanical behavior of the heart muscle tissues is the central problem in finite element simulation of the heart contraction, excitation propagation and development of an artificial heart. Nonlinear elastic and viscoelastic passive material properties of the left ventricular papillary muscle of a guinea pig heart were determined based on in-vitro precise uniaxial and relaxation tests. The nonlinear elastic behavior was modeled by a hypoelastic model and different hyperelastic strain energy functions such as Ogden and Mooney-Rivlin. Nonlinear least square fitting and constrained optimization were conducted under MATLAB and MSC.MARC in order to obtain the model material parameters. The experimental tensile data was used to get the nonlinear elastic mechanical behavior of the heart muscle. However, stress relaxation data was used to determine the relaxation behavior as well as viscosity of the tissues. Viscohyperelastic behavior was constructed by a multiplicative decomposition of a standard Ogden strain energy function, W, for instantaneous deformation and a relaxation function, R(t), in a Prony series form. The study reveals that hypoelastic and hyperelastic (Ogden) models fit the tissue mechanical behaviors well and can be safely used for heart mechanics simulation. Since the characteristic relaxation time (900 s) of heart muscle tissues is very large compared with the actual time of heart beating cycle (800 ms), the effect of viscosity can be reasonably ignored. The amount and type of experimental data has a strong effect on the Ogden parameters. The in vitro passive mechanical properties are good initial values to start running the biosimulation codes for heart mechanics. However, an optimization algorithm is developed, based on clinical intact heart measurements, to estimate and re-correct the material parameters in order to get the in vivo mechanical properties, needed for very accurate bio-simulation and for the development of new materials for the

  20. Influence of intra-molecular flexibility on the elastic property of double-stranded DNA film on a substrate

    Science.gov (United States)

    Wu, Jun-Zheng; Meng, Wei-Lie; Tang, Heng-Song; Zhang, Neng-Hui

    2017-05-01

    DNA film self-assembled or nanografted on a substrate, as a kind of soft matter, consists of fixed DNA chains endowed with negative charges and an aqueous solution full of cations, anions and water molecules. Their thermal/electrical/mechanical properties are closely related to the complex biodetection signals in nano-/micro-scale biosensors and other new genome technologies. This makes it important to properly characterize these properties. In this paper, the effect of flexible micro-scale configurations on the elastic moduli of DNA films is investigated. First, illuminated by Qiu’s sphere model, an alternative bead-chain model in terms of the Yukawa potential is presented for flexible intra-DNA configurations to describe interactions between DNA fragments. The effective charges of coarse-grained DNA beads could be derived, in which the empirical parameters are identified by curve fitting with Qiu’s experimental data. Second, the updated mesoscopic bead-chain model and the thought experiment of a continuum compression bar are used to compare the elastic moduli of double-stranded DNA (dsDNA) films prepared by self-assembling and nanografting techniques. Configurational sampling is achieved via Monte Carlo simulation. Our predictions quantitatively or qualitatively agree well with the relevant experiments on the effective charge of dsDNA from low to moderate monovalent counterion concentration, immobilization deflection of single-stranded DNA (ssDNA) or dsDNA microcantilever with the variation of salt concentration, and elastic modulus of ssDNA film in the air. The results reveal that different solution environment stimulates the diverse mechanical properties of dsDNA film on a substrate, and the end effect (i.e. terminal group effect) makes self-assembling dsDNA film stiffer in the sense of the same average packing density.

  1. Effect of pressure variation on structural, elastic, mechanical, optoelectronic and thermodynamic properties of SrNaF3 fluoroperovskite

    Science.gov (United States)

    Erum, Nazia; Azhar Iqbal, Muhammad

    2017-12-01

    The effect of pressure variation on structural, electronic, elastic, mechanical, optical and thermodynamic characteristics of cubic SrNaF3 fluoroperovskite have been investigated by employing first-principles method within the framework of gradient approximation (GGA). For the total energy calculations, we have used the full-potential linearized augmented plane wave (FP-LAPW) method. Thermodynamic properties are computed in terms of quasi-harmonic Debye model. The pressure effects are determined in the range of 0–25 GPa, in which mechanical stability of SrNaF3 fluoroperovskite remains valid. A prominent decrease in lattice constant and bonds length is observed with the increase in pressure from 0 to 25 GPa. The effect of increase in pressure on band structure calculations with GGA and GGA plus Tran–Blaha modified Becke–Johnson (TB-mBJ) potential reveals a predominant characteristic associated with widening of bandgap. The influence of pressure on set of isotropic elastic parameters and their related properties are numerically estimated for SrNaF3 polycrystalline aggregate. Apart of linear dependence of elastic coefficients, transition from brittle to ductile behavior is observed as pressure is increased from 0 to 25 GPa. We have successfully obtained variation of lattice constant, volume expansion, bulk modulus, Debye temperature and specific heat capacities with pressure and temperature in the range of 0–25 GPa and 0–600 K. All the calculated optical properties such as the complex dielectric function ε(ω), optical conductivity σ(ω), energy loss function L(ω), absorption coefficient α(w), refractive index n(ω), reflectivity R(ω), and effective number of electrons n eff, via sum rules shift towards the higher energies under the application of pressure.

  2. Structural and elastic properties of defect chalcopyrite HgGa{sub 2}S{sub 4} under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Gomis, O., E-mail: osgohi@fis.upv.es [Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Santamaría-Pérez, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universitat de València, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 València (Spain); Departamento de Química Física I, Universidad Complutense de Madrid, MALTA Consolider Team, Avenida Complutense s/n, 28040 Madrid (Spain); Vilaplana, R.; Luna, R. [Centro de Tecnologías Físicas: Acústica, Materiales y Astrofísica, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Sans, J.A.; Manjón, F.J. [Instituto de Diseño para la Fabricación y Producción Automatizada, MALTA Consolider Team, Universitat Politècnica de València, 46022 València (Spain); Errandonea, D. [Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universitat de València, Edificio de Investigación, C/Dr. Moliner 50, Burjassot, 46100 València (Spain); and others

    2014-01-15

    Highlights: • Single crystals of HgGa{sub 2}S{sub 4} with defect-chalcopyrite (DC) structure were synthesized. • High-pressure X-ray diffraction in DC-HgGa{sub 2}S{sub 4} was performed. • Equation of state of DC-HgGa{sub 2}S{sub 4} determined (bulk modulus of 48.4 GPa). • Calculated elastic constants of DC-HgGa{sub 2}S{sub 4} reported at different pressures. • DC-HgGa{sub 2}S{sub 4} becomes mechanically unstable above 13.8 GPa. -- Abstract: In this work, we focus on the study of the structural and elastic properties of mercury digallium sulfide (HgGa{sub 2}S{sub 4}) at high pressures. This compound belongs to the family of AB{sub 2}X{sub 4} ordered-vacancy compounds and exhibits a tetragonal defect chalcopyrite structure. X-ray diffraction measurements at room temperature have been performed under compression up to 15.1 GPa in a diamond anvil cell. Our measurements have been complemented and compared with ab initio total energy calculations. The axial compressibility and the equation of state of the low-pressure phase of HgGa{sub 2}S{sub 4} have been experimentally and theoretically determined and compared to other related ordered-vacancy compounds. The pressure dependence of the theoretical cation–anion and vacancy-anion distances and compressibilities in HgGa{sub 2}S{sub 4} are reported and discussed in comparison to other related ordered-vacancy compounds. Finally, the pressure dependence of the theoretical elastic constants and elastic moduli of HgGa{sub 2}S{sub 4} has been studied. Our calculations indicate that the low-pressure phase of HgGa{sub 2}S{sub 4} becomes mechanically unstable above 13.8 GPa.

  3. Properties of radioactive wastes and waste containers. Progress report No. 7, October--December 1977

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, P.; Neilson, Jr, R. M.

    1978-04-01

    Trial solidifications were made using portland type II cement--sodium silicate as the solidification agent. The sodium silicate was found to produce an initial rapid set for all wastes because of the precipitation of relatively insoluble silicate compounds upon reaction with soluble multivalent cations in solution in the cement-waste mixture. Achievement of the ultimate waste form strength required time intervals similar to waste forms produced using portland cement alone. A hard waste form was not obtained within seventy-eight days with formulations used to solidify boric acid waste. The flash points and flame points of Pioneer 221 bitumen and bitumen waste forms were determined using the Cleveland open cup method. The bitumen alone had a flash point of 610 +- 2/sup 0/F and a flame point of 668 +- 4/sup 0/F. The bitumen waste forms exhibited similar flame points but slightly higher (15 to 20/sup 0/F) flash points were measured. Self-irradiation exposure dose curves were calculated for BWR and PWR waste forms. These curves indicate the cumulative waste form exposure dose with time and serve as the basis for radiation stability experiments. Waste form specific activities of 0.01 to 100 Ci/ft/sup 3/ were considered. Bitumen waste forms containing sodium sulfate from the solidification of BWR chemical regenerative waste were prepared and leach tested. These specimens swelled and cracked during leach testing, exposing substantial new surface area to the leachant. The volumetric efficiencies of urea-formaldehyde and portland type II cement for various wastes and waste/binder ratios were calculated from compression test specimen data.

  4. Investigation into the supramolecular properties of fibres regenerated from cotton based waste garments.

    Science.gov (United States)

    Haule, L V; Carr, C M; Rigout, M

    2016-06-25

    This paper investigated the supramolecular properties and accessibility of fibres regenerated from cotton-based waste garments and compared to typical lyocell fibres. The supramolecular and accessibility properties of the cotton-based waste garments fibres regenerated from three sources (waste denim garments, easy care finished cotton fabrics and a blend of cotton-based waste garment with wood pulp) were analysed and compared to the lyocell fibres. The Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and Wide Angle X-ray Diffraction (WAXD) analyses indicated that the fibres from cotton waste garments had supramolecular properties similar to the typical lyocell fibres. The exception was spun from the cotton pulp reclaimed from easy care treated cotton fabrics and maybe related to increased amorphous cellulose content in its structure. The fibre's accessibility by reagents behaviour correlated well with the supramolecular properties. The results indicate that the waste garment purification process may affect the properties of the pulp and hence the supramolecular properties of the resultant fibres. Further research on the purification and regeneration of fibres from waste garments may lead to the use of cotton waste garments as an alternative feedstock source to the lyocell process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Anisotropy and temperature dependence of structural, thermodynamic, and elastic properties of crystalline cellulose Iβ: a first-principles investigation

    Science.gov (United States)

    Dri, Fernando L.; Shang, ShunLi; Hector, Louis G., Jr.; Saxe, Paul; Liu, Zi-Kui; Moon, Robert J.; Zavattieri, Pablo D.

    2014-12-01

    Anisotropy and temperature dependence of structural, thermodynamic and elastic properties of crystalline cellulose Iβ were computed with first-principles density functional theory (DFT) and a semi-empirical correction for van der Waals interactions. Specifically, we report the computed temperature variation (up to 500 K) of the monoclinic cellulose Iβ lattice parameters, constant pressure heat capacity, Cp, entropy, S, enthalpy, H, the linear thermal expansion components, ξi, and components of the isentropic and isothermal (single crystal) elastic stiffness matrices, CijS (T) and CijT (T) , respectively. Thermodynamic quantities from phonon calculations computed with DFT and the supercell method provided necessary inputs to compute the temperature dependence of cellulose Iβ properties via the quasi-harmonic approach. The notable exceptions were the thermal conductivity components, λi (the prediction of which has proven to be problematic for insulators using DFT) for which the reverse, non-equilibrium molecular dynamics approach with a force field was applied. The extent to which anisotropy of Young's modulus and Poisson's ratio is temperature-dependent was explored in terms of the variations of each with respect to crystallographic directions and preferred planes containing specific bonding characteristics (as revealed quantitatively from phonon force constants for each atomic pair, and qualitatively from charge density difference contours). Comparisons of the predicted quantities with available experimental data revealed reasonable agreement up to 500 K. Computed properties were interpreted in terms of the cellulose Iβ structure and bonding interactions.

  6. Elastic properties and stress-temperature phase diagrams of high-temperature phases with low-temperature lattice instabilities

    Science.gov (United States)

    Thomas, John C.; Van der Ven, Anton

    2014-12-01

    The crystal structures of many technologically important high-temperature phases are predicted to have lattice instabilities at low temperature, making their thermodynamic and mechanical properties inaccessible to standard first principles approaches that rely on the (quasi) harmonic approximation. Here, we use the recently developed anharmonic potential cluster expansion within Monte Carlo simulations to predict the effect of temperature and anisotropic stress on the elastic properties of ZrH2, a material that undergoes diffusionless transitions among cubic, tetragonal, and orthorhombic phases. Our analysis shows that the mechanical properties of high-temperature phases with low-temperature vibrational instabilities are very sensitive to temperature and stress state. These findings have important implications for materials characterization and multi-scale simulations and suggest opportunities for enhanced strain engineering of high-temperature phases exhibiting soft-mode instabilities.

  7. The study of the elastic properties of carbonate rocks on a base of laboratory and field measurement

    Directory of Open Access Journals (Sweden)

    Iwona Stan-Kłeczek

    2016-04-01

    were carried out from different quarries from the south part of Poland. The shape of samples is a cuboid with dimensions 0,1 x 0,05 x 0,05 m. The Pundit Lab+ equipment was used for tests. It measures the transmission time of an ultrasonic wave. P- and S- wave velocity are obtained for each sample. Seismic velocity values allowed for the calculation of the dynamic elastic moduli. The application of laboratory methods allowed obtaining information about the physical properties of rocks. This knowledge makes easier recognition in preliminary stages during engineering study

  8. The Role of Evolutive Elastic Properties in the Performance of a Sheet Formed Spring Applied in Multimedia Car Industry

    Directory of Open Access Journals (Sweden)

    Silva Joel

    2016-01-01

    Full Text Available The manufacturing process and the behavior of a sheet formed spring manufactured from an aluminum sheet is described and investigated in this work considering the specifications for the in-service conditions. The sheet formed spring is intended to be applied in car multimedia industry to replace bolted connections. Among others, are investigated the roles of the constitutive parameters and the hypothesis of evolutive elastic properties with the plastic work in the multi-step forming process and in working conditions.

  9. ELEMENTARY APPROACH TO SELF-ASSEMBLY AND ELASTIC PROPERTIES OF RANDOM COPOLYMERS

    Energy Technology Data Exchange (ETDEWEB)

    S. M. CHITANVIS

    2000-10-01

    The authors have mapped the physics of a system of random copolymers onto a time-dependent density functional-type field theory using techniques of functional integration. Time in the theory is merely a label for the location of a given monomer along the extent of a flexible chain. We derive heuristically within this approach a non-local constraint which prevents segments on chains in the system from straying too far from each other, and leads to self-assembly. The structure factor is then computed in a straightforward fashion. The long wave-length limit of the structure factor is used to obtain the elastic modulus of the network. It is shown that there is a surprising competition between the degree of micro-phase separation and the elastic moduli of the system.

  10. Elastic constants and thermophysical properties of Al-Mg-Si alloys from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fenglian; Guo, Fei; Chen, Hongmei; Tao, Xiaoma [Ministry of Education, Guangxi Univ., Nanning (China). Key Lab. of New Processing Technology for Nonferrous Metals and Materials; Ouyang, Yifang [Ministry of Education, Guangxi Univ., Nanning (China). Key Lab. of New Processing Technology for Nonferrous Metals and Materials; Central South Univ., Changsha (China). State Key Lab. of Powder Metallurgy; Feng, Yuanping [National Univ. of Singapore (Singapore). Dept. of Physics; Du, Yong [Central South Univ., Changsha (China). State Key Lab. of Powder Metallurgy

    2010-11-15

    The lattice constants and elastic constants for Al-Mg-Si alloys have been calculated by using first-principles total energy calculations within the generalized gradient approximation. The calculated results are in good agreement with available experimental and theoretical results. The polycrystalline shear modulus, Young's modulus and Poisson's ratio are also estimated from the calculated single crystalline elastic constants. The Young's modulus and shear modulus increase following the precipitation sequence in Al-Mg-Si. The Debye sound velocity, Debye temperature, Grueneisen constant, heat capacity and linear coefficients of thermal expansion are predicted for the considered Al-Mg-Si alloys based on the Debye-Grueneisen model. The calculated values of Mg{sub 2}Si agree well with the previous experimental and theoretical results. (orig.)

  11. Real-Time Measurement of Material Elastic Properties in a High Gamma Irradiation Environment

    Energy Technology Data Exchange (ETDEWEB)

    Ken Telschow; Rob Schley; Dave Cottle

    2006-05-01

    This paper describes the first noncontact elastic vibration measurements of an object in a high gamma radiation field. Using a laser-coupled resonant ultrasound technique, the vibration modes of an Inconel hollow capped cylinder were measured as the gamma radiation field was increased to 104 Gy/h. This measurement technique allowed shifts in the resonant frequency of the sample’s vibration modes to be tracked over a 170-h period. The vibration mode frequencies changed in a manner consistent with the temperature dependence of the elastic stiffness coefficients of the material. These results demonstrate the efficacy of the laser approach for real-time resonant ultrasound measurements in this severely hostile nuclear environment.

  12. Simulation of the Elastic Properties of Reinforced Kevlar-Graphene Composites

    OpenAIRE

    Martirosyan, Karen S; Zyskin, M.

    2012-01-01

    The compressive strength of unidirectional fiber composites in the form of Kevlar yarn with a thin outer layer of graphene was investigated and modeled. Such fiber structure may be fabricated by using a strong chemical bond between Kevlar yarn and graphene sheets. Chemical functionalization of graphene and Kevlar may achieved by modification of appropriate surface-bound functional (e.g., carboxylic acid) groups on their surfaces. In this report we studied elastic response to unidirectional in...

  13. Structural motifs and elastic properties of hierarchical biological tissues - a review.

    Science.gov (United States)

    Bar-On, Benny; Wagner, H Daniel

    2013-08-01

    Recent progress made in the field of hierarchical biological materials is reviewed with an emphasis on the staggering characteristics at the smaller structural scale of a number of tissues. We show by means of selected examples that the small-scale architecture, and particularly the degree of staggering and overlap, plays a critical role in the macroscopic elastic behavior of those tissues. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Tailoring Elastic Properties of Silica Aerogels Cross-Linked with Polystyrene

    Science.gov (United States)

    Nguyen, Baochau N.; Meador, Mary Ann B.; Tousley, Marissa E.; Shonkwiler, Brian; McCorkle, Linda; Scheiman, Daniel A.; Palczer, Anna

    2009-01-01

    The effect of incorporating an organic linking group, 1,6-bis(trimethoxysilyl)hexane (BTMSH), into the underlying silica structure of a styrene cross-linked silica aerogel is examined. Vinyltrimethoxysilane (VTMS) is used to provide a reactive site on the silica backbone for styrene polymerization. Replacement of up to 88 mol 1 of the silicon from tetramethoxyorthosilicate with silicon derived from BTMSH and VTMS during the making of silica gels improves the elastic behavior in some formulations of the crosslinked aerogels, as evidenced by measurement of the recovered length after compression of samples to 251 strain. This is especially true for some higher density formulations, which recover nearly 100% of their length after compression to 251 strain twice. The compressive modulus of the more elastic monoliths ranged from 0.2 to 3 MPa. Although some of these monoliths had greatly reduced surface areas, changing the solvent used to produce the gels from methanol to ethanol increased the surface area in one instance from 6 to 220 sq m2/g with little affect on the modulus, elastic recovery, porosity, or density.

  15. Tire-Pavement Friction Characteristics with Elastic Properties of Asphalt Pavements

    Directory of Open Access Journals (Sweden)

    Miao Yu

    2017-11-01

    Full Text Available The skid-resisting performance of pavement is a critical factor in traffic safety. Recent studies primarily analyze this behavior by examining the macro or micro texture of the pavement. It is inevitable that skid-resistance declines with time because the texture of pavement deteriorates throughout its service life. The primary objective of this paper is to evaluate the use of different asphalt pavements, varying in resilience, to optimize braking performance on pavement. Based on the systematic dynamics of tire-pavement contact, and analysis of the tire-road coupled friction mechanism and the effect of enlarging the tire-pavement contact area, road skid resistance was investigated by altering the elastic modulus of asphalt pavement. First, this research constructed the kinetic contact model to simulate tire-pavement friction. Next, the following aspects of contact behaviors were studied when braking: tread deformation in the tangential pavement interface, actual tire-pavement contact in the course, and the frictional braking force transmitted from the pavement to the tires. It was observed that with improvements in pavement elasticity, the actual tire-pavement contact area increased, which gives us the ability to effectively strengthen the frictional adhesion of the tire to the pavement. It should not be overlooked that the improvement in skid resistance was caused by an increase in pavement elasticity. This research approach provides a theoretical basis and design reference for the anti-skid research of asphalt pavements.

  16. Hanford Waste Physical and Rheological Properties: Data and Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Beric E.; Kurath, Dean E.; Mahoney, Lenna A.; Onishi, Yasuo; Huckaby, James L.; Cooley, Scott K.; Burns, Carolyn A.; Buck, Edgar C.; Tingey, Joel M.; Daniel, Richard C.; Anderson, K. K.

    2011-08-01

    The Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shell tanks (SSTs) and 28 double -hell tanks (DSTs). Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection’s (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks.

  17. EFFECTS OF POLYTHENE FIBRES ON SELECTED PROPERTIES ...

    African Journals Online (AJOL)

    eobe

    solid waste recycling companies in Nigeria. Despite the fact that these bags have elastic properties yet the ... be used in making of man-made timber. Brick, stone, concrete and other waste can replace sand after ... quality of concrete produced with polymer waste as partial replacement of fine aggregate with a view to.

  18. Influence of bismuth on structural, elastic and spectroscopic properties of Nd{sup 3+} doped Zinc–Boro-Bismuthate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Gaurav; Sontakke, Atul D.; Karmakar, P.; Biswas, K.; Balaji, S.; Saha, R.; Sen, R.; Annapurna, K., E-mail: annapurnak@cgcri.res.in

    2014-05-01

    The present investigation reports, influence of bismuth addition on structural, elastic and spectral properties of [(99.5−x) {4ZnO−3B_2O_3}−0.5Nd{sub 2}O{sub 3}−x Bi{sub 2}O{sub 3} where x=0, 5, 10, 20, 30, 40, 50 and 60] glasses. The measured FTIR reflectance spectra facilitated a thorough insight of methodical modifications that are arising in the glass structure from borate (build by BO{sub 3} and BO{sub 4} units) to bismuthate (BiO{sub 3} and BiO{sub 6} units) network due to the increase of bismuth content ensuing with a steady decrease in host phonon energy (ν{sub ph}). The elastic properties estimated from measured longitudinal and shear ultrasonic velocities (U{sub L} and U{sub s}) demonstrated the reduction in network rigidity of glasses on Bi{sub 2}O{sub 3} inclusion. The three phenomenological Judd–Ofelt intensity parameters (Ω{sub 2,4,6}) were obtained from recorded absorption spectra of Nd{sup 3+} ions in these glasses and have been used to predict radiative properties as a function of variation in bismuth content. The reduced host phonon energy and high optical basicity effect due to Bi{sub 2}O{sub 3} incorporation remarkably improved the Nd{sup 3+} luminescence properties such as emission intensity, quantum yield and emission cross-section. The quantum yield showed a strong increase from mere 16% in Zinc–Borate glass to almost 73% in 60 mol% Bi{sub 2}O{sub 3} containing glass. Similarly, the emission cross-section for Nd{sup 3+4}F{sub 3/2}→{sup 4}I{sub 11/2} laser transition raised from 2.43×10{sup −20} cm{sup 2} to 3.95×10{sup −20} cm{sup 2} in studied concentration suggesting a strong improvement in Nd{sup 3+} laser spectroscopic properties in Zinc–Boro-Bismuthate glass. These materials may be promising for compact solid state infrared lasers. - Highlights: • Continuous structural changes associated with reduction in host phonon energy by Bi{sub 2}O{sub 3} inclusion. • Ultrasonic velocity study revealed reduced Debye

  19. EFFECT OF PAPER WASTE ON CONCRETE PROPERTIES: SUSTAINABILITY APPROACH

    OpenAIRE

    Patil Asha, Sarvankar Dipti, Palte Rupali, Prof. Patil Prerana

    2017-01-01

    In Construction field is widely developed from day to day. The development is causing the increasing needs of raw materials such as gravel. This high demand is causing the materials becoming extinct. Apart from that, this world also had facing the high amount of waste products which including waste paper. Research has proven that the waste paper can be used as recycled paper in construction field. The construction industry consumes a large amount of non-renewable resources. On the other hand,...

  20. Properties of fired clay brick incorporating with sewage sludge waste

    Science.gov (United States)

    Kadir, Aeslina Abdul; Salim, Nurul Salhana Abdul; Sarani, Noor Amira; Rahmat, Nur Aqma Izurin; Abdullah, Mohd Mustafa Al Bakri

    2017-09-01

    The production of sludge in wastewater treatment plant is about to increase every year and most of the sludge was directly disposed to landfill. In addition, the constraint to treat sludge is very high in cost and time- consuming could be disadvantages to the responsible parties. Therefore, this research was conducted to utilize sludge produced from the wastewater treatment plant into fired clay brick as one of the alternatives of disposal method. In this study, the research attempt to incorporate sewage sludge waste (SSW) into fired clay brick. The sewage sludge brick (SSB) mixtures were incorporated with 0%, 1%, 5%, 10%, and 20% of SSW. The manufactured bricks were fired at 1050°C with heating rate of 1°C/min. Physical and mechanical properties test were conducted such as shrinkage, density, water absorption and compressive strength. As the conclusion, brick with utilization 5% of SSW is acceptable to produce good quality of brick. This study shows by using SSW in fired clay brick could be an alternative method to dispose of the SSW and also could act as a replacement material for brick manufacturing with appropriate mix and design.

  1. Ab initio localized basis set study of structural parameters and elastic properties of HfO{sub 2} polymorphs

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, M A [Facultad de Ingenieria, Universidad Nacional del Nordeste, Avenida Las Heras 727, 3500-Resistencia (Argentina); Casali, R A [Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avenida Libertad, 5600-Corrientes (Argentina)

    2005-09-21

    The SIESTA approach based on pseudopotentials and a localized basis set is used to calculate the electronic, elastic and equilibrium properties of P 2{sub 1}/c, Pbca, Pnma, Fm3m, P4{sub 2}nmc and Pa3 phases of HfO{sub 2}. Using separable Troullier-Martins norm-conserving pseudopotentials which include partial core corrections for Hf, we tested important physical properties as a function of the basis set size, grid size and cut-off ratio of the pseudo-atomic orbitals (PAOs). We found that calculations in this oxide with the LDA approach and using a minimal basis set (simple zeta, SZ) improve calculated phase transition pressures with respect to the double-zeta basis set and LDA (DZ-LDA), and show similar accuracy to that determined with the PPPW and GGA approach. Still, the equilibrium volumes and structural properties calculated with SZ-LDA compare better with experiments than the GGA approach. The bandgaps and elastic and structural properties calculated with DZ-LDA are accurate in agreement with previous state of the art ab initio calculations and experimental evidence and cannot be improved with a polarized basis set. These calculated properties show low sensitivity to the PAO localization parameter range between 40 and 100 meV. However, this is not true for the relative energy, which improves upon decrease of the mentioned parameter. We found a non-linear behaviour in the lattice parameters with pressure in the P 2{sub 1}/c phase, showing a discontinuity of the derivative of the a lattice parameter with respect to external pressure, as found in experiments. The common enthalpy values calculated with the minimal basis set give pressure transitions of 3.3 and 10.8?GPa for P2{sub 1}/c {yields} Pbca and Pbca {yields} Pnma, respectively, in accordance with different high pressure experimental values.

  2. Ab-initio study of phase stability, elastic and thermodynamic properties of AlY alloy under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dawei [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China); Su, Taichao [Institute of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000 (China); Song, Haizhen; Lu, Cheng; Zhong, Zhiguo; Lu, Zhiwen [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China); Pu, Chunying, E-mail: puchunying@126.com [College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061 (China)

    2015-11-05

    Using the particle swarm optimization algorithm combined with first-principles methods, we explore the diagram of AlY alloy up to 250 GPa. It is found that AlDy phase, rather than the experimentally observed B2 phase, is the most stable structure at 0 K and 0–20 GPa. However, our results show that B2 phase can exist as a stable phase at 20–27.6 GPa. At higher pressure, four new high-pressure phases with Cmcm-I, Cmcm-II, I4/mmm and P4/nmm structure are identified for the first time. The hardness, elastic and thermodynamic properties of the newly found phases are investigated and compared with B2 phase. The calculated hardness of AlDy, Cmcm-I, Cmcm-II, I4/mmm and P4/nmm phases is in the range of 7–9 GPa, higher than that of B2 phase. In addition, it is found that AlDy phase is a brittle material at 0 GPa, which changes to a ductile material above 12 GPa. Except for AlDy phase, all the other AlY compounds exhibit completely ductile behavior under pressure. Compared with the other phases, B2 phase is found to have the best ductility and the largest elastic anisotropy over the whole pressure investigated. Moreover, all AlY intermetallics exhibit a nearly elastic isotropy in compressibility but a comparatively large elastic anisotropy in shear. The structural stability, electronic structure, bulk and shear modulus, Debye temperature as well as sound velocities of AlY alloy under pressure are also deeply discussed. - Graphical abstract: Pressure-induced phase transition of AlY alloy up to 250 GPa. - Highlights: • The diagram of AlY alloy was explored and four new stable phases were predicted. • B2 phase shows the largest ductility and elastic anisotropy among AlY alloys. • All AlY alloys exhibit ductile behavior except for AlDy phase under pressure. • All AlY alloys show strong isotropy in compressibility and anisotropy in shear.

  3. Graphene Oxide/Polyacrylamide/Aluminum Ion Cross-Linked Carboxymethyl Hemicellulose Nanocomposite Hydrogels with Very Tough and Elastic Properties.

    Science.gov (United States)

    Kong, Weiqing; Huang, Danyang; Xu, Guibin; Ren, Junli; Liu, Chuanfu; Zhao, Lihong; Sun, Runcang

    2016-06-06

    Development of high-strength hydrogels has recently attracted ever-increasing attention. In this work, a new design strategy has been proposed to prepare graphene oxide (GO)/polyacrylamide (PAM)/aluminum ion (Al(3+) )-cross-linked carboxymethyl hemicellulose (Al-CMH) nanocomposite hydrogels with very tough and elastic properties. GO/PAM/Al-CMH hydrogels were synthesized by introducing graphene oxide (GO) into PAM/CMH hydrogel, followed by ionic cross-linking of Al(3+) . The nanocomposite hydrogels were characterized by means of FTIR, X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analysis (SEM-EDX) along with their swelling and mechanical properties. The maximum compressive strength and the Young's modulus of GO3.5 /PAM/Al-CMH0.45 hydrogel achieved values of up to 1.12 and 13.27 MPa, increased by approximately 6488 and 18330 % relative to the PAM hydrogel (0.017 and 0.072 MPa). The as-prepared GO/PAM/Al-CMH nanocomposite hydrogels possess high strength and great elasticity giving them potential in bioengineering and drug-delivery system applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Office blood pressure is a predictor of aortic elastic properties and urinary protein excretion in subjects with white coat hypertension.

    Science.gov (United States)

    Aznaouridis, Konstantinos; Vlachopoulos, Charalambos; Masoura, Konstantina; Pietri, Panagiota; Vyssoulis, Gregory; Ioakeimidis, Nikolaos; Stefanadis, Christodoulos; Tousoulis, Dimitrios

    2016-01-15

    White coat hypertension (WCH) is related to target organ damage and increased cardiovascular risk. Arterial elastic properties and urinary protein excretion are determinants of cardiovascular performance and predictors of outcomes. We investigated whether office blood pressure (BP) is a better determinant of arterial and renal function than the ambulatory BP in WCH patients. We studied 440 consecutive untreated non-diabetic patients with WCH (office BP >140/90 mmHg, mean daytime ambulatory BP 0.5). Hierarchical multilevel linear regression analysis showed that office systolic BP is an independent determinant of cfPWV (P=0.050), AIx (P=0.029), albumin (P=0.002) and ACR (P=0.001) and has a borderline association with α1-microglobulin (P=0.088). In non-diabetic WCH individuals, office systolic BP is an independent predictor of aortic elastic properties and urinary protein excretion, whereas ambulatory BP is not. This finding suggests that office BP may be a marker of cardiovascular risk in subjects with WCH. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. An ab initio prediction study of the electronic structure and elastic properties of V3GeC2

    Directory of Open Access Journals (Sweden)

    Guobing Ying

    2017-06-01

    Full Text Available The electronic structure and elastic properties of the ternary layered carbide V3GeC2 were investigated by the first-principle plane-wave pseudopotential total energy calculation method based on density functional theory. It is found that the computed P63/mmc lattice constants and internal coordinates are a = 2.9636 Å, c = 17.2256 Å and zV2 = 0.1325, zC = 0.5712, respectively. The predictable cohesive energy of V3GeC2 reflects that it could be a stable Mn+1AXn phase like Ti3GeC2 and V2GeC, while the band structure shows that the V3GeC2 has anisotropic electrical conductivity, with a high density of states at the Fermi energy. The V3GeC2 exhibits potential anisotropic elastic properties, as well as self-lubricating and ductile behaviour, related to the V–Ge bonds being relatively weaker than the V–C bonds.

  6. Analytical applications and effective properties of a second gradient isotropic elastic material model

    Science.gov (United States)

    Enakoutsa, Koffi

    2015-06-01

    Recently, the works by Toupin, Mindlin, Sokolowski and Germain have been developed following two research streams. In the first one, higher-order gradient continuum models were developed based on the Cauchy tetrahedron argument (see, e.g., dell'Isola and Seppecher in Comptes Rendus de l Academie de Sciences 17 Serie IIb: Mecanique, Physique, Chimie, Astronomie 321:303-308, 1995, Meccanica 32:33-52 1997, Zeitschrift fr Angewandte Mathematik und Physik 63(6):1119-1141, 2012). In the second one, the structure of higher-order gradient models is developed with a view to the applications. In particular in the model of linear isotropic solids proposed by Dell'Isola, Sciarra and Vidoli (DSV), the main constitutive equation is obtained for the case of second gradient models. This model introduces in addition to the two well-known Lame's elastic constants five constitutive constants. The practical applications of this model remain in its infancy since the issue of determining the new moduli it introduces is not yet completely addressed. Also, analytical solutions of simple boundary value problems that can be helpful to grasp some of the physical foundations of this model are missing. This paper aims to address these two issues by providing the analytical solutions for two model problems, a spherical shell subjected to axisymmetric loading conditions and the circular bending of a beam in plane strain, both the beam and the shell obeying the DSV second gradient isotropic elastic model. The solution of the circular bending of a beam has served to grasp some of the physical soundness of the model. A framework based on homogenization under inhomogeneous boundary conditions is also suggested to determine the unknown constitutive constants, which are provided in the particular case of elastic porous heterogeneous materials.

  7. Mechanical properties of concrete containing recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate replacement

    Science.gov (United States)

    Khalid, Faisal Sheikh; Azmi, Nurul Bazilah; Sumandi, Khairul Azwa Syafiq Mohd; Mazenan, Puteri Natasya

    2017-10-01

    Many construction and development activities today consume large amounts of concrete. The amount of construction waste is also increasing because of the demolition process. Much of this waste can be recycled to produce new products and increase the sustainability of construction projects. As recyclable construction wastes, concrete and ceramic can replace the natural aggregate in concrete because of their hard and strong physical properties. This research used 25%, 35%, and 45% recycled concrete aggregate (RCA) and ceramic waste as coarse aggregate in producing concrete. Several tests, such as concrete cube compression and splitting tensile tests, were also performed to determine and compare the mechanical properties of the recycled concrete with those of the normal concrete that contains 100% natural aggregate. The concrete containing 35% RCA and 35% ceramic waste showed the best properties compared with the normal concrete.

  8. Decay property of regularity-loss type of solutions in elastic solids with voids

    KAUST Repository

    Said-Houari, Belkacem

    2013-12-01

    In this article, we consider two porous systems of nonclassical thermoelasticity in the whole real line. We discuss the long-time behaviour of the solutions in the presence of a strong damping acting, together with the heat effect, on the elastic equation and establish several decay results. Those decay results are shown to be very slow and of regularity-loss type. Some improvements of the decay rates have also been given, provided that the initial data belong to some weighted spaces. © 2013 Copyright Taylor and Francis Group, LLC.

  9. Effect of focusing flow on stationary spot machining properties in elastic emission machining.

    Science.gov (United States)

    Takei, Yoshinori; Mimura, Hidekazu

    2013-05-16

    Ultraprecise optical elements are applied in advanced optical apparatus. Elastic emission machining (EEM) is one of the ultraprecision machining methods used to fabricate shapes with 0.1-nm accuracy. In this study, we proposed and experimentally tested the control of the shape of a stationary spot profile by introducing a focusing-flow state between the nozzle outlet and the workpiece surface in EEM. The simulation results indicate that the focusing-flow nozzle sharpens the distribution of the velocity on the workpiece surface. The results of machining experiments verified those of the simulation. The obtained stationary spot conditions will be useful for surface processing with a high spatial resolution.

  10. Elastic-properties measurement at high temperatures through contact resonance atomic force microscopy

    DEFF Research Database (Denmark)

    Marinello, Francesco; Pezzuolo, Andrea; Carmignato, Simone

    2015-01-01

    . To this regard, some open issues are of particular interest: low depth of penetration, high lateral resolution and measurements at elevated temperatures. An interesting solution is given by acoustic microscopy techniques, which can be successfully implemented for advanced research in surface elasticity, allowing...... during scanning, in order to allow exploitation of high resolution measurements at relatively high temperatures. Such instrument set up was undergone a set of calibration experiments in order to allow not only qualitative but also quantitative characterization of surfaces. The work was completed...... with a feasibility study with mechanical and topography measurements at temperatures as high as 150°C, with lateral resolution lower than 100 nm....

  11. FP-LAPW study of structural, electronic, elastic, mechanical and thermal properties of AlFe intermetallic

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Ekta, E-mail: jainekta05@gmail.com [Department of Physics, Government M. L. B. Girls P. G. Autonomous College, Bhopal-462002 (India); Pagare, Gitanjali, E-mail: gita-pagare@yahoo.co.in [Department of Physics, Sarojini Naidu Government Girls P. G. Autonomous College, Bhopal-462016 (India); Sanyal, S. P., E-mail: sps.physicsbu@gmail.com [Department of Physics, Barkatullah University, Bhopal-462026 (India)

    2016-05-06

    The structural, electronic, elastic, mechanical and thermal properties of AlFe intermetallic compound in B{sub 2}-type (CsCl) structure have been investigated using first-principles calculations. The exchange-correlation term was treated within generalized gradient approximation. Ground state properties i.e. lattice constants (a{sub 0}), bulk modulus (B) and first-order pressure derivative of bulk modulus (B’) are presented. The density of states are derived which show the metallic character of present compound. Our results for C{sub 11}, C{sub 12} and C{sub 44} agree well with previous theoretical data. Using Pugh’s criteria (B/G{sub H} < 1.75), brittle character of AlFe is satisfied. In addition shear modulus (G{sub H}), Young’s modulus (E), sound wave velocities and Debye temperature (θ{sub D}) have also been estimated.

  12. Evaluation of thermal insulation and mechanical properties of waste rubber/natural rubber composite

    Directory of Open Access Journals (Sweden)

    M.M. Abdel Kader

    2012-04-01

    Full Text Available The influences of waste rubber loading on mechanical and thermal conductivity properties were investigated for NR composite. An experimental investigation was carried out to obtain low cost construction material with desirable mechanical and thermal insulation properties. Natural rubber was loaded with different concentrations of waste rubber (200, 400, 600, 800, and 1000 phr. The addition of waste rubber leads to a slight increase in thermal conductivity values of composites but it still lies around range of thermal insulating materials. Also addition of waste rubber leads to improvement of mechanical properties of composites. The crosslink density of NR composite increases with the increase of waste rubber loading until 600 phr and after that it decreases due to the stronger the rubber–filler interaction. This leads to the decrease of the swelling index that has the opposite trend of crosslink density. So, the sample with 600 phr waste rubber is considered the optimum concentration from the swelling measurement. Filler loading results in pronounced increase in the tensile modulus and decease in the elongation at fracture which reflects the reinforcement effect of the filler. The yield stress increases with waste rubber loading increment. This delays the permanent disruption of matrix morphology. So, the optimum concentration which is 600 phr waste rubber loading agrees with the swelling and mechanical measurements which has desirable thermal insulation and high mechanical properties and decreases the cost of materials to 82% of the NR cost.

  13. Self-assembly of suspended graphene wrinkles with high pre-tension and elastic property

    Science.gov (United States)

    Yang, Liusi; Niu, Tianxiao; Zhang, Hui; Xu, Wenjing; Zou, Mingchu; Xu, Lu; Cao, Guoxin; Cao, Anyuan

    2017-12-01

    Wrinkles exist universally in graphene-based structures, yet their controlled fabrication remains challenging; most graphene wrinkles have been produced either in attachment to elastic substrates or limited in small single sheets. Here, we utilize the phenomenon of gel-cracking to generate uniaxial strains locally on solution-precipitated graphene oxide (GO) sheets, thus creating suspended and aligned wrinkles over the trenches between cracked TiO2 islands. In particular, those GO wrinkles are subjected to a high pre-tension, which is important for making stable suspended configuration, as confirmed by theoretical calculations based on the wrinkle geometry and measured spring constants, respectively. As a result, in situ atomic force microscope indentation reveals elastic deformation with tunable spring constants depending on the gap width. We further obtain chemically reduced GO wrinkles with enhanced spring constants and reversible behavior after 1000 indentation cycles. Our suspended and aligned graphene wrinkles have potential applications in many areas such as sensors, actuators, and micro/nano electromechanical systems.

  14. Evaluating the Effect of Finishing Materials on Viscous Elastic Properties of Particle Boards

    Directory of Open Access Journals (Sweden)

    Jonas VOBOLIS

    2012-09-01

    Full Text Available In the present research the investigation of finishing wood particle boards is presented. The testing process of wood particle boards involved an original stand. The following three types of finished boards underwent evaluation: finished with veneer on both sides, finished with veneer on the one side and with compensatory paper on the other side, and finished with melamine impregnated paper on both sides. It was established that the first vibrational modes of finished wood particle boards in two perpendicular directions share similarity with modes of the beam-shaped body in terms of their shape. It was obtained that the modulus of elasticity of wood particle boards with different finishing differs by approximately 30 % – 70 % in two perpendicular directions. It was established that when dealing with boards finished with veneer on both sides, with veneer on the one side and compensatory paper on the other side, and with melamine impregnated paper, the value of the modulus of elasticity in two perpendicular directions differs by 1.71, 1.54 and 1.34 times, respectively. It was found that in the case of boards finished with veneer on both sides and with veneer on the one side and compensatory paper on the other side, the coefficient of damping change in two perpendicular directions is less than the one of the board finished with melamine impregnated paper by 25 %.DOI: http://dx.doi.org/10.5755/j01.ms.18.3.2436

  15. Chemical and mechanical performance properties for various final waste forms -- PSPI scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Farnsworth, R.K.; Larsen, E.D.; Sears, J.W.; Eddy, T.L.; Anderson, G.L.

    1996-09-01

    The US DOE is obtaining data on the performance properties of the various final waste forms that may be chosen as primary treatment products for the alpha-contaminated low-level and transuranic waste at the INEL`s Transuranic Storage Area. This report collects and compares selected properties that are key indicators of mechanical and chemical durability for Portland cement concrete, concrete formed under elevated temperature and pressure, sulfur polymer cement, borosilicate glass, and various forms of alumino-silicate glass, including in situ vitrification glass and various compositions of iron-enriched basalt (IEB) and iron-enriched basalt IV (IEB4). Compressive strength and impact resistance properties were used as performance indicators in comparative evaluation of the mechanical durability of each waste form, while various leachability data were used in comparative evaluation of each waste form`s chemical durability. The vitrified waste forms were generally more durable than the non-vitrified waste forms, with the iron-enriched alumino-silicate glasses and glass/ceramics exhibiting the most favorable chemical and mechanical durabilities. It appears that the addition of zirconia and titania to IEB (forming IEB4) increases the leach resistance of the lanthanides. The large compositional ranges for IEB and IEB4 more easily accommodate the compositions of the waste stored at the INEL than does the composition of borosilicate glass. It appears, however, that the large potential variation in IEB and IEB4 compositions resulting from differing waste feed compositions can impact waste form durability. Further work is needed to determine the range of waste stream feed compositions and rates of waste form cooling that will result in acceptable and optimized IEB or IEB4 waste form performance. 43 refs.

  16. Low-temperature phase transition in γ-glycine single crystal. Pyroelectric, piezoelectric, dielectric and elastic properties

    Energy Technology Data Exchange (ETDEWEB)

    Tylczyński, Zbigniew, E-mail: zbigtyl@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Busz, Piotr [Institute of Molecular Physics, Polish Academy of Science, Smoluchowskiego 17, 60-179 Poznań (Poland)

    2016-11-01

    Temperature changes in the pyroelectric, piezoelectric, elastic and dielectric properties of γ-glycine crystals were studied in the range 100 ÷ 385 K. The pyroelectric coefficient increases monotonically in this temperature range and its value at RT was compared with that of other crystals having glycine molecules. A big maximum in the d14 component of piezoelectric tensor compared by maximum in attenuation of the resonant face-shear mode were observed at 189 K. The components of the elastic stiffness tensor and other components of the piezoelectric tensor show anomalies at this temperature. The components of electromechanical coupling coefficient determined indicate that γ-glycine is a weak piezoelectric. The real and imaginary part of the dielectric constant measured in the direction perpendicular to the trigonal axis show the relaxation anomalies much before 198 K and the activation energies were calculated. These anomalies were interpreted as a result of changes in the NH{sub 3}{sup +} vibrations through electron-phonon coupling of the so called “dynamical transition”. The anomalies of dielectric constant ε*{sub 11} and piezoelectric tensor component d{sub 14} taking place at 335 K are associated with an increase in ac conductivity caused by charge transfer of protons. - Graphical abstract: Imaginary part of dielectric constant in [100] direction. - Highlights: • Piezoelectric, elastic and dielectric constants anomalies were discovered at 189 K. • These anomalies were interpreted as a result of so called “dynamical transition”. • Relaxational dielectric anomaly was explained by the dynamics of glycine molecules. • Pyroelectric coefficient of γ-glycine was determined in a wide temperature range. • Complex dielectric & piezoelectric anomalies at 335 K were caused by protons hopping.

  17. Systematic study of the elastic properties of Mn{sub 3}AC antiperovskite with A = Zn, Al, Ga, In, Tl, Ge and Sn

    Energy Technology Data Exchange (ETDEWEB)

    Medkour, Y.; Roumili, A. [Laboratoire d' Etudes des Surfaces et Interfaces des Materiaux Solides (LESIMS), Universite de Setif (Algeria); Maouche, D., E-mail: djmaouche@yahoo.fr [Laboratory for Developing New Materials and their Characterizations, University of Setif (Algeria); Saoudi, A.; Louail, L. [Laboratory for Developing New Materials and their Characterizations, University of Setif (Algeria)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer Single crystal elastic constants C{sub 11}, C{sub 12} and C{sub 44} were calculated. Black-Right-Pointing-Pointer Elastic moduli for polycrystalline aggregate were obtained. Black-Right-Pointing-Pointer Increasing the atomic number of A element reduces B, G Prime , Y and v. Black-Right-Pointing-Pointer Mn{sub 3}AlC has a high melting point and light weight. - Abstract: First principle calculations were made to investigate the elastic properties of Mn{sub 3}AC antiperovskites, A = Zn, Al, Ga, In, Tl, Ge and Sn. The estimated equilibrium lattice parameters are in agreement with the experimental ones. From the single crystal elastic constants we have calculated the polycrystalline elastic moduli: the bulk modulus B, shear modulus G, tetragonal shear modulus G Prime , Young's modulus Y, Cauchy's pressure CP, Poisson's ratio v, elastic anisotropy factor and Pugh's criterion G/B. Using Debye's approximation we have deduced the elastic wave velocities and Debye's temperature.

  18. Non-linear elastic deformations

    CERN Document Server

    Ogden, R W

    1997-01-01

    Classic in the field covers application of theory of finite elasticity to solution of boundary-value problems, analysis of mechanical properties of solid materials capable of large elastic deformations. Problems. References.

  19. Impact of gas injection on the apparent viscosity and viscoelastic property of waste activated sewage sludge.

    Science.gov (United States)

    Bobade, Veena; Baudez, Jean Christophe; Evans, Geoffery; Eshtiaghi, Nicky

    2017-05-01

    Gas injection is known to play a major role on the particle size of the sludge, the oxygen transfer rate, as well as the mixing efficiency of membrane bioreactors and aeration basins in the waste water treatment plants. The rheological characteristics of sludge are closely related to the particle size of the sludge floc. However, particle size of sludge floc depends partly on the shear induced in the sludge and partly on physico-chemical nature of the sludge. The objective of this work is to determine the impact of gas injection on both the apparent viscosity and viscoelastic property of sludge. The apparent viscosity of sludge was investigated by two methods: in-situ and after sparging. Viscosity curves obtained by in-situ measurement showed that the apparent viscosity decreases significantly from 4000 Pa s to 10 Pa s at low shear rate range (below 10 s-1) with an increase in gas flow rate (0.5LPM to 3LPM); however the after sparging flow curve analysis showed that the reduction in apparent viscosity throughout the shear rate range is negligible to be displayed. Torque and displacement data at low shear rate range revealed that the obtained lower apparent viscosity in the in-situ method is not the material characteristics, but the slippage effect due to a preferred location of the bubbles close to the bob, causing an inconsistent decrease of torque and increase of displacement at low shear rate range. In linear viscoelastic regime, the elastic and viscous modulus of sludge was reduced by 33% & 25%, respectively, due to gas injection because of induced shear. The amount of induced shear measured through two different tests (creep and time sweep) were the same. The impact of this induced shear on sludge structure was also verified by microscopic images. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Quantum-mechanical study of tensorial elastic and high-temperature thermodynamic properties of grain boundary states in superalloy-phase Ni3Al

    Science.gov (United States)

    Friák, Martin; Všianská, Monika; Holec, David; Šob, Mojmír

    2017-07-01

    Grain boundaries (GBs), the most important defects in solids and their properties are crucial for many materials properties including (in-)stability. Quantum-mechanical methods can reliably compute properties of GBs and we use them to analyze (tensorial) anisotropic elastic properties of interface states associated with GBs in one of the most important intermetallic compounds for industrial applications, Ni3Al. Selecting the Σ5(210) GBs as a case study because of its significant extra volume, we address the mechanical stability of the GB interface states by checking elasticity-based Born stability criteria. One critically important elastic constant, C 55, is found nearly three times smaller at the GB compared with the bulk, contributing thus to the reduction of the mechanical stability of Ni3Al polycrystals. Next, comparing properties of Σ5(210) GB state which is fully relaxed with those of a Σ5(210) GB state when the supercell dimensions are kept equal to those in the bulk we conclude that lateral relaxations have only marginal impact on the studied properties. Having the complete elastic tensor of Σ5(210) GB states we combine Green’s-function based homogenization techniques and an approximative approach to the Debye model to compare thermodynamic properties of a perfect Ni3Al bulk and the Σ5(210) GB states. In particular, significant reduction of the melting temperature (to 79-81% of the bulk value) is predicted for nanometer-size grains.

  1. Micro-finite-element method to assess elastic properties of trabecular bone at micro- and macroscopic level.

    Science.gov (United States)

    Rieger, R; Auregan, J C; Hoc, T

    2017-09-08

    The objective of the present study is to assess the mechanical behavior of trabecular bone based on microCT imaging and micro-finite-element analysis. In this way two methods are detailed: (i) direct determination of macroscopic elastic property of trabecular bone; (ii) inverse approach to assess mechanical properties of trabecular bone tissue. Thirty-five females and seven males (forty-two subjects) mean aged (±SD) 80±11.7 years from hospitals of Assistance publique-Hôpitaux de Paris (AP-HP) diagnosed with osteoporosis following a femoral neck fracture due to a fall from standing were included in this study. Fractured heads were collected during hip replacement surgery. Standardized bone cores were removed from the femoral head's equator by a trephine in a water bath. MicroCT images acquisition and analysis were performed with CTan® software and bone volume fraction was then determined. Micro-finite-element simulations were per-formed using Abaqus 6.9-2® software in order to determine the macroscopic mechanical behaviour of the trabecular bone. After microCT acquisition, a longitudinal compression test was performed and the experimental macroscopic Young's Modulus was extracted. An inverse approach based on the whole trabecular bone's mechanical response and micro-finite-element analysis was performed to determine microscopic mechanical properties of trabecular bone. In the present study, elasticity of the tissue was shown to be similar to that of healthy tissue but with a lower yield stress. Classical histomorphometric analysis form microCT imaging associated with an inverse micro-finite-element method allowed to assess microscopic mechanical trabecular bone parameters. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Decay property of regularity-loss type for solutions in elastic solids with voids

    KAUST Repository

    Djouamai, Leila

    2014-01-01

    In this paper, we consider the Cauchy problem for a system of elastic solids with voids. First, we show that a linear porous dissipation leads to decay rates of regularity-loss type of the solution. We show some decay estimates for initial data in Hs(R)∩L1(R). Furthermore, we prove that by restricting the initial data to be in Hs(R)∩L1,γ(R) and γ. ∈. [0, 1], we can derive faster decay estimates of the solution. Second, we show that by adding a viscoelastic damping term, then we gain the regularity of the solution and obtain the optimal decay rate. © 2013 Elsevier Ltd.

  3. Experimental Investigation of Effects of Vibration upon Elastic and Cohesive Properties of Beds of Wet Sand

    Directory of Open Access Journals (Sweden)

    S. Alsop

    1995-01-01

    Full Text Available The transmission of sinusoidal vibrations through beds of cohesive particulate solids was measured. Results were interpreted in terms of a critical state model to predict the elastic swelling constant k, and the cohesive stress C. Factorial experimental design was used to identify significant parameters. Factors that affect k include percent moisture, bulk density, sample size, sample shape, the presence of a supporting membrane, and loading order. Factors that affect C include percent moisture and particle size distribution. Factors affecting k were interpreted in terms of their effects upon bed structure and factors affecting C in terms of an equivalent pore water pressure due to capillary and liquid bridge effects. The critical state model was modified to incorporate general relationships between axial and radial strains.

  4. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials.

    Science.gov (United States)

    Sikora, Pawel; Augustyniak, Adrian; Cendrowski, Krzysztof; Horszczaruk, Elzbieta; Rucinska, Teresa; Nawrotek, Pawel; Mijowska, Ewa

    2016-08-18

    The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

  5. Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

    Directory of Open Access Journals (Sweden)

    Pawel Sikora

    2016-08-01

    Full Text Available The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100% to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

  6. Investigations on the influences of elastic foundations on the aerothermoelastic flutter and thermal buckling properties of lattice sandwich panels in supersonic airflow

    Science.gov (United States)

    Chai, Yu-Yang; Song, Zhi-Guang; Li, Feng-Ming

    2017-11-01

    The lattice sandwich panels supported on elastic mediums are often applied in the construction of aerospace structures because of the low specific weight, excellent bending rigidity and outstanding vibration properties. This elastic medium can be any spring materials including damping tapes or heat shields which are attached to one side of the sandwich panel. Therefore, in this paper, aerothermoelastic flutter and thermal buckling characteristics of sandwich panels with the pyramidal lattice core resting on elastic foundations in supersonic airflow are studied. The influences of geometrical parameters and elastic foundation on the panel flutter and thermal buckling of the structures are analyzed in detail. In the structural modeling, the first-order shear deformation theory is applied, and the effective material properties of the lattice core are used. The aerodynamic pressure is evaluated by the supersonic piston theory. Hamilton's principle and the assumed modes method are applied to formulate the equation of motion. The highlight point of this investigation is that an effective thermal buckling suppression method utilizing the elastic foundation is proposed, based on which the thermal buckling of the structure can be completely eliminated with the natural frequencies remaining unchanged when the shearing layer parameter is equal to the thermal load. Through the numerical results, the influences of the elastic foundation, aspect ratio, core-to-facesheet thickness ratio, and inclination angle of the core truss on the aerothermoelastic behaviors of the lattice sandwich panel are analyzed, and the thermal buckling elimination effects are also examined.

  7. First principles calculations of structural, elastic, electronic properties of Ir{sub 3}Zr with L1{sub 2} structure under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Na; Wang, Xueye, E-mail: wxueye@xtu.edu.cn; Wan, Yali

    2015-07-15

    The effects of pressure on the structural, elastic and electronic properties of Ir{sub 3}Zr are investigated by means of the first-principles calculations based on the density functional theory with generalized gradient approximation and local density approximation methods. The calculated lattice parameters and elastic modulus of Ir{sub 3}Zr at zero pressure are in good agreement with available experimental and theoretical results. The values of elastic constants (C{sub 11}, C{sub 12}, C{sub 44}), bulk modulus (B), shear modulus (G), Young modulus (E), Poisson's ratio (υ), anisotropy index (A) and Debye temperature (T{sub D}) present the linearly increasing dependences on the external pressure. Additionally, the B/G values exhibit an upward trend with increasing pressure, which means that higher pressure can improve its ductility. Ir{sub 3}Zr exhibits a brittle characteristic at zero pressure. When the pressure reaches 10 GPa, the Cauchy pressure and B/G value show ductile feature. In addition, the pressure-dependence behavior of density of states, Mulliken charge and bond length are analyzed. - Graphical abstract: Display Omitted - Highlights: • The elastic and electronic properties of Ir{sub 3}Zr under pressure are investigated. • The elastic constants, elastic moduli increase with the pressure increasing. • When the pressure reaches 10 GPa, Ir{sub 3}Zr changes from brittle to ductile. • Ir{sub 3}Zr remains as a stable structure and no structural transition under pressure.

  8. An ab initio study of the structural, elastic, electronic and optical properties of the newly synthesized nitridoaluminate LiCaAlN2

    Science.gov (United States)

    Haddadi, K.; Bouhemadou, A.; Bin-Omran, S.; Maabed, S.; Khenata, R.

    2015-01-01

    The structural parameters, elastic constants, electronic structure and optical properties of the recently reported monoclinic quaternary nitridoaluminate LiCaAlN2 are investigated in detail using the ab initio plane-wave pseudopotential method within the generalized gradient approximation. The calculated equilibrium structural parameters are in excellent agreement with the experimental data, which validate the reliability of the applied theoretical method. The chemical and structural stabilities of LiCaAlN2 are confirmed by calculating the cohesion energy and enthalpy of formation. Chemical band stiffness is calculated to explain the pressure dependence of the lattice parameters. Through the band structure calculation, LiCaAlN2 is predicted to be an indirect band gap of 2.725 eV. The charge-carrier effective masses are estimated from the band structure dispersions. The frequency-dependent dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity coefficient and electron energy loss function spectra are calculated for polarized incident light in a wide energy range. Optical spectra exhibit a noticeable anisotropy. Single-crystal and polycrystalline elastic constants and related properties, including isotropic sound velocities and Debye temperatures, are numerically estimated. The calculated elastic constants and elastic compliances are used to analyse and visualize the elastic anisotropy of LiCaAlN2. The calculated elastic constants demonstrate the mechanical stability and brittle behaviour of the considered material.

  9. Elastic properties and electronic structure of WS{sub 2} under pressure from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics; Civil Aviation Flight Univ. of China, Guanghan (China). Dept. of Physics; Zeng, Zhao-Yi [Chongqing Normal Univ., Chongqing (China). College of Physics and Electronic Engineering; Liang, Ting; Tang, Mei; Cheng, Yan [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics

    2017-07-01

    The influence of pressure on the elastic and mechanical properties of the hexagonal transition-metal dichalcogenide WS{sub 2} is investigated using the first-principles calculations. With the increase in pressure, the lattice parameters and the volume of WS{sub 2} decrease, which is exactly in agreement with the available experimental data and other calculated results. The elastic constants C{sub ij}, bulk modulus B, shear modulus G, Young's modulus E, and Poisson's ratio σ of WS{sub 2} also increase with pressure. At last, for the first time, the band gaps of energy, the partial density of states, and the total density of states under three different pressures are obtained and analysed. It is found that the band gap of WS{sub 2} decreases from 0.843 to 0 eV when the external pressure varies from 0 to 20 GPa, which implies that WS{sub 2} may transform from semiconductors to semimetal phase at a pressure about 20 GPa.

  10. Structural, Elastic, and Electronic Properties of Antiperovskite Chromium-Based Carbides ACCr3 (A = Al and Ga

    Directory of Open Access Journals (Sweden)

    D. F. Shao

    2013-01-01

    Full Text Available We theoretically investigated antiperovskite chromium-based carbides ACCr3 through the first-principles calculation based on density functional theory (DFT. The structure optimization shows that the lattice parameter of ACCr3 is basically proportional to the radius of A-site elements. The calculated formation energies show that AlCCr3 and GaCCr3 can be synthesized at ambient pressure and are stable with nonmagnetic ground states. Based on the calculation of elastic constants, some elastic, mechanical, and thermal parameters are derived and discussed. AlCCr3 and GaCCr3 show ductile natures and may have similar thermal properties. From the analysis of the electronic structures, it was found that there are electron and hole bands that cross the Fermi level for AlCCr3 and GaCCr3, indicating multiple-band natures. The Fermi level locates at the vicinity of the density of states (DOSs peak, which leads to a large DOS at Fermi level dominated by Cr-3d electrons. The band structures of AlCCr3 and GaCCr3 are very similar to those of the superconducting antiperovskite MgCNi3. The similarity may make AlCCr3 and GaCCr3 behave superconductively, which needs to be further investigated in theoretical and experimental studies.

  11. Properties of Mortar Containing Waste Glass and Limestone Filler

    OpenAIRE

    Karamanoğlu, B; EREN, Özgür

    2008-01-01

    The building material industry has been developed due to the increasing population. This brings chronic shortage of building materials. According to this the civil engineers have been challenged to convert the industrial wastes to useful building and construction materials. The purpose of using ground waste glass is protect the environment by saving more landfills, to increase the cement plant capacity by using more beneficial additives, and to reduce CO2 emission per ton of...

  12. Fiberglass wastes/polyester resin composites: mechanical properties and water sorption

    Directory of Open Access Journals (Sweden)

    Edcleide M. Araújo

    2006-12-01

    Full Text Available The mechanical properties of polyester/fiberglass composites were studied. The aim of this work was to evaluate the possibility of reusing the wastes taken from spray-up processing of Paraíba state Industries as reinforcement in polyester matrix composites. Composites with 20, 30, 40, 50 and 60 wt. (% of recycled fiberglass were prepared by compression molding and compared with polyester/ virgin glass fiber composites. The mechanical properties and water sorption behavior were evaluated. The results showed that fiberglass wastes are promising to be reused in polyester resin composites. The impact strength was excellent. It can be concluded that the reusing of the fiberglass wastes is viable.

  13. Soil mechanical properties of MBT waste from Luxembourg, Germany and Thailand

    Directory of Open Access Journals (Sweden)

    Pattaraporn Pimolthai

    2014-12-01

    Full Text Available Mechanical and biological treatments (MBT of waste have become well known in Europe and Asia. The maximum particle size of waste is reduced by the removal of larger plastic materials from municipal solid waste during mechanical processing. The mechanical properties of the MBT waste are significantly changed by this process. An effective treatment system can lead to a better quality of output materials which do not cause environmental problems. This paper shows the comparative mechanical properties of MBT wastes from Luxembourg, Germany and Thailand. This research focused on the smaller 10 mm-fraction of MBT samples, in order to describe and evaluate the potential application of the small size material as a cover liner in landfill sites. Therefore the smaller 10 mm-fraction of MBT samples were tested for geotechnical properties. The small size waste particles were analysed in laboratory tests in order to determine their particle size, particle shape, compaction, permeability, shear strength, porosity and water absorption capacity, including comparison with the properties of soil material. The results showed that reduced particles were likely to act as a compact, low permeable material with a high potential for water absorption. The amount of remaining fibre and foil components in the materials cause different mechanical and hydraulic behaviours in the samples. The leachate of MBT samples showed very low concentrations of chemical oxygen demand, ammonium, and heavy metals, compared to the landfill leachate of untreated waste.

  14. Characterization of Elastic Properties in Basalts of the Western Snake River Plain, Idaho: a Mechanostratigraphic Analysis of a Potential Geothermal Reservoir

    Science.gov (United States)

    Kessler, J. A.; Evans, J. P.; Schmitt, D. R.; Shervais, J. W.

    2013-12-01

    The western Snake River Plain is a region of high crustal heat flow and has the potential for commercial geothermal energy development. High-temperature crystalline reservoirs commonly have connected fracture networks and other discontinuities that provide the primary fluid storage and permeability (Type I fractures). A borehole was drilled during the DOE/ICDP Snake River Scientific Drilling Program near Mountain Home, Idaho to a depth of ~1,800 m (6,000 ft) with 85 - 90% slimhole core recovery to assess the potential for geothermal energy development. A high-temperature artesian flow zone was encountered in basalt at a depth of 1,745 m (5,726 ft) in the MH-2 borehole with fluid temperatures above 140°C (240°F). Analysis of geomechanical behavior of rocks requires an understanding of basic physical and elastic properties under dynamic in-situ stress conditions. Here we conduct unconfined uniaxial compressive stress experiments on core samples to measure static elastic properties and compressive strength over a ~305 m (1,000 ft) interval of the borehole above and including the geothermal reservoir. Acoustic velocities are measured under pressure and temperature scenarios to calculate dynamic elastic properties and describe the anisotropy of elastic moduli and compressive strength. Dynamic elastic properties are calculated from dipole sonic borehole log data and compare the results to the previous dynamic and static interpretations. The comparison demonstrates that the calculation of dynamic elastic properties from borehole data is an effective method to interpret and describe mechanical stratigraphy and elastic properties in the case that core is not available for analysis in this area. Natural fractures, induced fractures, and breakouts are mapped in acoustic televiewer data. Fracture density is calculated and compared to lithological and mechanical stratigraphy, defined by the physical properties, elastic properties, and strength measurements. The stratigraphic

  15. Elastic properties of carbon phases obtained from C sub 6 sub 0 under pressure: the first example of anisotropic disordered carbon solid

    CERN Document Server

    Brazhkin, V V; Mukhamadiarov, V V; Gromnitskaya, E L; Lyapin, A G; Popova, S V; Stalgorova, O V

    2002-01-01

    We observe an anisotropy of the propagation velocities of longitudinal and transverse ultrasonic waves, as well as of the hardness, for disordered graphite-like samples obtained from the C sub 6 sub 0 fullerite, which is heated to different temperatures under a pressure of 7.5 GPa. The anisotropy of the elastic properties and the hardness is connected to the additional pressure component that occurs in the quasi-hydrostatic experimental conditions. The elastic characteristics of the samples are determined. We propose a model description relating the observed properties of superhard sp sup 2 carbon to its possible structural features and to the mechanism of its formation.

  16. Elastic properties of Nafion, polybenzimidazole and poly [2,5-benzimidazole] membranes determined by AFM tip nano-indentation

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, Esteban A. [Departamento de Fisica de Materia Condensada, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), 1650 San Martin, Buenos Aires (Argentina); Corti, Horacio R. [Departamento de Fisica de Materia Condensada, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica (CNEA), 1650 San Martin, Buenos Aires (Argentina); Instituto de Quimica Fisica de los Materiales, Medio Ambiente y Energia (INQUIMAE), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellon II, Ciudad Universitaria, 1428 Buenos Aires (Argentina)

    2009-03-15

    The mechanical properties of polybenzimidazole (PBI) and poly [2,5-benzimidazole] (ABPBI) membranes, possible candidates to replace Nafion as proton exchange membranes in direct methanol fuel cells (DMFC), were studied. It was observed by AFM imaging that the morphology of the ABPBI membranes strongly depends on the casting procedure, performed at high temperature from methanesulphonic acid and at low temperature from formic acid. The elastic moduli of the undoped and phosphoric acid doped membranes were determined using the AFM force spectroscopy technique and the differences observed with doped and undoped PBI and Nafion membranes, were discussed in terms of the electrostatic and swelling forces between polymer chains. The analysis of the force curves indicates differences in the mechanical behavior of doped PBI and ABPBI membranes compared to Nafion, which could have practical consequences on the stability of the membrane electrode assemblies. (author)

  17. Computational modeling of elastic properties of carbon nanotube/polymer composites with interphase regions. Part II: Mechanical modeling

    KAUST Repository

    Han, Fei

    2014-01-01

    We present two modeling approaches for predicting the macroscopic elastic properties of carbon nanotubes/polymer composites with thick interphase regions at the nanotube/matrix frontier. The first model is based on local continuum mechanics; the second one is based on hybrid local/non-local continuum mechanics. The key computational issues, including the peculiar homogenization technique and treatment of periodical boundary conditions in the non-local continuum model, are clarified. Both models are implemented through a three-dimensional geometric representation of the carbon nanotubes network, which has been detailed in Part I. Numerical results are shown and compared for both models in order to test convergence and sensitivity toward input parameters. It is found that both approaches provide similar results in terms of homogenized quantities but locally can lead to very different microscopic fields. © 2013 Elsevier B.V. All rights reserved.

  18. Effect of solid distribution on elastic properties of open-cell cellular solids using numerical and experimental methods.

    Science.gov (United States)

    Zargarian, A; Esfahanian, M; Kadkhodapour, J; Ziaei-Rad, S

    2014-09-01

    Effect of solid distribution between edges and vertices of three-dimensional cellular solid with an open-cell structure was investigated both numerically and experimentally. Finite element analysis (FEA) with continuum elements and appropriate periodic boundary condition was employed to calculate the elastic properties of cellular solids using tetrakaidecahedral (Kelvin) unit cell. Relative densities between 0.01 and 0.1 and various values of solid fractions were considered. In order to validate the numerical model, three scaffolds with the relative density of 0.08, but different amounts of solid in vertices, were fabricated via 3-D printing technique. Good agreement was observed between numerical simulation and experimental results. Results of numerical simulation showed that, at low relative densities (numerical simulation and considering the relative density and solid fraction in vertices, empirical relations were derived for Young׳s modulus and Poisson׳s ratio. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Laboratory assessment of the influence of the proportion of waste foundry sand on the geotechnical engineering properties of clayey soils

    CSIR Research Space (South Africa)

    Mgangira, Martin B

    2006-01-01

    Full Text Available Soil improvement can be achieved through mechanical stabilisation using industrial byproducts. Clayey soils were blended with waste foundry sand to examine its influence on the geotechnical engineering properties of the soils. The waste foundry sand...

  20. Structural, electronic, elastic and superconducting properties of noble metal nitrides MN{sub 2} (M = Ru, Rh, Pd)

    Energy Technology Data Exchange (ETDEWEB)

    Puvaneswari, S. [Department of Physics, E.M.G. Yadava Women' s College, Madurai, Tamilnadu 625 014 (India); Rajeswarapalanichamy, R., E-mail: rrpcaspd2003@gmail.com [Department of Physics, N.M.S.S. Vellaichamy Nadar College, Madurai, Tamilnadu 625019 (India); Sudha Priyanga, G. [Department of Physics, N.M.S.S. Vellaichamy Nadar College, Madurai, Tamilnadu 625019 (India)

    2015-02-01

    The structural stability, electronic structure, elastic and superconducting properties of noble metal nitrides MN{sub 2} (M = Ru, Rh, Pd) are investigated in tetragonal (P4/mbm), fluorite (Fm3m), orthorhombic (Pnnm), pyrite (Pa-3) and hexagonal (P6/mmm) phases using first principles calculations. The calculated lattice parameters are in good agreement with other theoretical results. Among the considered structures, RhN{sub 2} and PdN{sub 2} are found to be most stable in tetragonal structure, whereas RuN{sub 2} is stable in fluorite structure. A sequence of structural phase transition is predicted under high pressure in these metal nitrides. The electronic structure reveals that these nitrides are metallic. These metal nitrides are found to be covalent, ionic and metallic in the stable phase. The observations show that these metal nitrides are mechanically stable at ambient condition. The superconducting transition temperatures for RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are found to be 1.65 K, 5.01 K and 8.7 K respectively. - Highlights: • Electronic, structural and elastic properties of RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are studied. • A pressure induced structural phase transition is predicted. • Electronic structure reveals that these materials exhibit metallic behavior. • High bulk modulus indicates that RuN{sub 2}, RhN{sub 2} and PdN{sub 2} are superhard materials. • Superconducting temperature values are reported.

  1. Elastic-properties measurement at high temperatures through contact resonance atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Marinello, Francesco, E-mail: francesco.marinello@unipd.it; Pezzuolo, Andrea; Sartori, Luigi; Cavalli, Raffaele [University of Padova, Department of Land, Environment, Agriculture and Forestry, Viale dell’Università 16, 35020 Legnaro, Padova (Italy); Carmignato, Simone [University of Padova, Department of Management and Engineering, Stradella San Nicola 3, 36100 Vicenza (Italy); Savio, Enrico [University of Padova, Department of Industrial Engineering, Via Venezia 1, 35131 Padova (Italy); De Chiffre, Leonardo [Technical University of Denmark, Department of Mechanical Engineering, Produktionstorvet 425, 2800 Kgs. Lyngby (Denmark)

    2015-06-23

    Miniaturization of products and need for further improvement of machines performance introduce new serious challenges in materials characterization. In particular non-destructive mechanical testing in the sub-micrometer scale is needed to better understand and improve micro-manufacturing operations. To this regard, some open issues are of particular interest: low depth of penetration, high lateral resolution and measurements at elevated temperatures. An interesting solution is given by acoustic microscopy techniques, which can be successfully implemented for advanced research in surface elasticity, allowing fast direct and non-destructive measurement of Young’s modulus and related surface parameters. In this work an instrument set up for Contact Resonance Atomic Force Microscopy is proposed, where the sample with is coupled to a heating stage and a piezoelectric transducer directly vibrate the cantilever during scanning, in order to allow exploitation of high resolution measurements at relatively high temperatures. Such instrument set up was undergone a set of calibration experiments in order to allow not only qualitative but also quantitative characterization of surfaces. The work was completed with a feasibility study with mechanical and topography measurements at temperatures as high as 150°C, with lateral resolution lower than 100 nm.

  2. Elastic-properties measurement at high temperatures through contact resonance atomic force microscopy

    Science.gov (United States)

    Marinello, Francesco; Pezzuolo, Andrea; Carmignato, Simone; Savio, Enrico; De Chiffre, Leonardo; Sartori, Luigi; Cavalli, Raffaele

    2015-06-01

    Miniaturization of products and need for further improvement of machines performance introduce new serious challenges in materials characterization. In particular non-destructive mechanical testing in the sub-micrometer scale is needed to better understand and improve micro-manufacturing operations. To this regard, some open issues are of particular interest: low depth of penetration, high lateral resolution and measurements at elevated temperatures. An interesting solution is given by acoustic microscopy techniques, which can be successfully implemented for advanced research in surface elasticity, allowing fast direct and non-destructive measurement of Young's modulus and related surface parameters. In this work an instrument set up for Contact Resonance Atomic Force Microscopy is proposed, where the sample with is coupled to a heating stage and a piezoelectric transducer directly vibrate the cantilever during scanning, in order to allow exploitation of high resolution measurements at relatively high temperatures. Such instrument set up was undergone a set of calibration experiments in order to allow not only qualitative but also quantitative characterization of surfaces. The work was completed with a feasibility study with mechanical and topography measurements at temperatures as high as 150°C, with lateral resolution lower than 100 nm.

  3. A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property

    Energy Technology Data Exchange (ETDEWEB)

    Tsap, L V; Zhang, Y; Goldgof, D B; Sarkar, S

    2004-04-02

    A modeling approach is presented for quantitative burn scar assessment. Emphases are given to: (1) constructing a finite element model from natural image features with an adaptive mesh, and (2) quantifying the Young's modulus of scars using the finite element model and the regularization method. A set of natural point features is extracted from the images of burn patients. A Delaunay triangle mesh is then generated that adapts to the point features. A 3D finite element model is built on top of the mesh with the aid of range images providing the depth information. The Young's modulus of scars is quantified with a simplified regularization functional, assuming that the knowledge of scar's geometry is available. The consistency between the Relative Elasticity Index and the physician's rating based on the Vancouver Scale (a relative scale used to rate burn scars) indicates that the proposed modeling approach has high potentials for image-based quantitative burn scar assessment.

  4. Bonding, elastic and vibrational properties in low and high pressure synthesized diamond-like BCx phases

    Science.gov (United States)

    Zinin, P.; Liu, X. R.; Jia, R.; Sharma, S. K.; Ming, L. C.; Kutuza, I.; Troyan, I.

    2017-10-01

    Recent studies demonstrate that low pressure chemical vapor deposition at 950 K leads to the synthesis of diamond-like boron carbides with high concentrations of boron (0.66 chemical vapor deposition materials are mixtures of diamond-like and graphitic BCx phases. This finding allows us to revise the interpretation of the x-ray diffraction (XRD) patterns of the g-BC3 phases discussed previously [2, 3]. To support the new interpretation, we conducted a laser heating experiment of the g-BC3 phase. We found that after laser heating at 1100 K and 25 GPa in a diamond anvil cell (DAC) almost all graphitic layers of the g-BC3 transform into a cubic structure. The XRD pattern of the cubic BC3 phase (c-BC3) can be indexed with a cubic unit cell a = 3.619 (0.165) Å. Measurements of the equation of state of the g-BC3 phase demonstrated that boron atoms were incorporated into the graphitic B-C network. The linear compressibility along the c axis can be characterized by the value of the linear modulus Bc = 29.2 ± 1.8 GPa. Linear fitting of the experimental data for the a/a o parameter as a function of pressure gives us the value of the linear elastic modulus along the a axes: Ba = 800 ± 75 GPa.

  5. Influence of industrial solid waste addition on properties of soil-cement bricks

    Directory of Open Access Journals (Sweden)

    F. B. Siqueira

    Full Text Available Abstract The reuse of pollutant solid wastes produced in distinct industrial activities (avian eggshell waste and welding flux slag waste as a source of alternative raw material for producing soil-cement bricks for civil construction was investigated. Soil-cement bricks containing up to 30 wt% of industrial solid waste were uniaxially pressed and cured for 28 days. Special emphasis is given on the influence of solid waste addition on the technical properties (as such volumetric shrinkage, water absorption, bulk density, durability, and compressive strength, microstructure and mineral phases of soil-cement bricks. Microstructural evolution was evaluated via confocal microscopy. The experimental results showed that the solid wastes behave as charge material and influenced both technical properties and microstructure of the soil-cement bricks. It was found that up to 15 wt% of welding flux slag waste and up to 30 wt% of avian eggshell waste could be added into the soil-cement bricks for use as building material.

  6. Comparative first-principles calculations of the electronic, optical, elastic and thermodynamic properties of XCaF{sub 3} (X = K, Rb, Cs) cubic perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Li; Wang, Y.-J. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, 2 Chongwen Road, Nan' an District, Chongqing 400065 (China); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Liu, D.-X.; Ma, C.-G. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, 2 Chongwen Road, Nan' an District, Chongqing 400065 (China); Brik, M.G., E-mail: mikhail.brik@ut.ee [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, 2 Chongwen Road, Nan' an District, Chongqing 400065 (China); Institute of Physics, University of Tartu, W. Ostwald Str. 1, Tartu 50411 (Estonia); Institute of Physics, Jan Długosz University, Armii Krajowej 13/15, PL-42200 Częstochowa (Poland); Suchocki, A. [College of Mathematics and Physics, Chongqing University of Posts and Telecommunications, 2 Chongwen Road, Nan' an District, Chongqing 400065 (China); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Institute of Physics, Kazimierz Wielki University, Weyssenhoffa 11, 85-072 Bydgoszcz (Poland); Piasecki, M. [Institute of Physics, Jan Długosz University, Armii Krajowej 13/15, PL-42200 Częstochowa (Poland); Reshak, A.H. [New Technologies – Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic); School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia)

    2017-02-15

    Three fluoroperovskites with the general formula XCaF{sub 3} (X = K, Rb, Cs) have been systematically studied using the first-principles methods. The structural, electronic, optical, elastic and thermodynamic properties of these three compounds were calculated at the ambient and elevated hydrostatic pressure. Variation of all these properties with pressure was analyzed; it was shown that the structural and elastic constants change linearly with increased pressure, whereas the calculated band gaps follow the quadratic dependence on pressure. Influence of the first cation variation (K – Rb – Cs) on these properties was discussed. Elastic anisotropy (directional dependence of the Young moduli) of these compounds was modeled and analyzed for the first time. - Highlights: • Three cubic perovskites XCaF{sub 3} (X = K, Rb, Cs) were studied by ab initio methods. • Systematic variation of physical properties with the first cation change was traced. • Pressure effects on physical properties were calculated and modeled. • Debye temperature and Grüneisen constant for all materials were calculated for the first time. • Elastic anisotropy was visualized by plotting Young moduli directional dependences.

  7. Annealing effect on elastic, magnetic and magnetoelastic properties of CoFeB thin films on polymer substrate

    Science.gov (United States)

    Zighem, F.; Faurie, D.; Belmeguenai, M.; Girodon-Boulandet, N.; Gabor, M. S.; Djemia, P.

    2017-11-01

    We have studied the magnetomechanical properties of Co20 Fe60 B20 thin films deposited on polyimide substrate. Particularly, we studied the effect of annealing in the accessible temperature range (0-375 °C) allowed by the polymer substrate. Complementary techniques have been used to characterize the elastic, magnetic and magnetoelastic properties of annealed samples (Brillouin light scattering and tensile tests combined with in situ ferromagnetic resonance). Below 200 °C, no significant evolutions of the properties have been found excepted the magnetic damping parameter. In contrast, above 200 °C, strong variations are observed (+15% for Young’s modulus, -40% for magnetostriction coefficient and  +500% for the uniaxial magnetic anisotropy field). This is in correlation with the x-ray diffraction peak sharpening observed in the studied thin films. This is most probably due to exceeding of the glass transition temperature of the thin film. The complete data analysis allowed an estimation of the thermal stability of Co20 Fe60 B20 alloy thin films.

  8. Polyacrylamide hydrogels and semi-interpenetrating networks (IPNs) with poly(N-isopropylacrylamide): mechanical properties by measure of compressive elastic modulus.

    Science.gov (United States)

    Muniz, E C; Geuskens, G

    2001-01-01

    Semi-IPN hydrogels (based on cross-linked polyacrylamide having poly(N-isopropylacrylamide) (PN1PAAm) inside) were synthesized and their properties, such as swelling ratio and compressive elastic moduli, were studied at several temperatures. Equilibrium swelling ratios of semi-IPN markedly decreased due to the presence of less hydrophilic PNIPAAm chains. The semi-IPN presented greater elastic modulus when compared to the cross-linked PAAm hydrogel. The effect was explained as being an additional contribution of the PNIPAAm chains, which collapsed around the PAAm networks, to the elastic modulus. It was pointed out that the PAAm networks support the collapsed chains. According to the results presented in this work, semi-IPN hydrogels present better mechanical properties than the PAAm hydrogel, mainly when the PNIPAAm chains are in a collapsed state. Copyright 2001 Kluwer Academic Publishers

  9. Bonding, elastic and vibrational properties in low and high pressure synthesized diamond-like BCx phases

    Energy Technology Data Exchange (ETDEWEB)

    Zinin, P.; Liu, X. R.; Jia, R.; Sharma, S. K.; Ming, L. C.; Kutuza, I.; Troyan, I.

    2017-10-01

    Recent studies demonstrate that low pressure chemical vapor deposition at 950 K leads to the synthesis of diamond-like boron carbides with high concentrations of boron (0.66 < x < 4) in which the sp 2 fraction depends on the boron concentration [1]. This indicates that the graphitic BC3 (g-BC3) phases obtained by chemical vapor deposition materials are mixtures of diamond-like and graphitic BCx phases. This finding allows us to revise the interpretation of the x-ray diffraction (XRD) patterns of the g-BC3 phases discussed previously [2, 3]. To support the new interpretation, we conducted a laser heating experiment of the g-BC3 phase. We found that after laser heating at 1100 K and 25 GPa in a diamond anvil cell (DAC) almost all graphitic layers of the g-BC3 transform into a cubic structure. The XRD pattern of the cubic BC3 phase (c-BC3) can be indexed with a cubic unit cell a = 3.619 (0.165) Å. Measurements of the equation of state of the g-BC3 phase demonstrated that boron atoms were incorporated into the graphitic B-C network. The linear compressibility along the c axis can be characterized by the value of the linear modulus Bc = 29.2 ± 1.8 GPa. Linear fitting of the experimental data for the a/a o parameter as a function of pressure gives us the value of the linear elastic modulus along the a axes: Ba = 800 ± 75 GPa.

  10. Effect of Different Organic Wastes on Soil Propertie s and Plant Growth and Yield: a Review

    Directory of Open Access Journals (Sweden)

    Hossain M. Z.

    2017-12-01

    Full Text Available The use of organic wastes in agriculture plays a great role in recycling essential plant nutrients, sustaining soil security as well as protecting the environment from unwanted hazards. This review article deals with the effect of different kinds of organic wastes on soil properties and plant growth and yield. Municipal solid waste is mainly used as a source of nitrogen and organic matter, improving soil properties and microbial activity that are closely related to soil fertility. Biowaste and food waste increase pH, nitrogen content, cation exchange capacity, water holding capacity, and microbial biomass in soil. Sewage sludge contains various amounts of organic matter and huge amounts of plant nutrients. Manure is a common waste which improves soil properties by adding nutrients and increases microbial and enzyme activity in soil. It also reduces toxicity of some heavy metals. These organic wastes have a great positive impact on soil physical, chemical, and biological properties as well as stimulate plant growth and thus increase the yield of crops.

  11. Effects of a Pseudophysiological Environment on the Elastic and Viscoelastic Properties of Collagen Gels

    Directory of Open Access Journals (Sweden)

    Sébastien Meghezi

    2012-01-01

    Full Text Available Vascular tissue engineering focuses on the replacement of diseased small-diameter blood vessels with a diameter less than 6 mm for which adequate substitutes still do not exist. One approach to vascular tissue engineering is to culture vascular cells on a scaffold in a bioreactor. The bioreactor establishes pseudophysiological conditions for culture (medium culture, 37°C, mechanical stimulation. Collagen gels are widely used as scaffolds for tissue regeneration due to their biological properties; however, they exhibit low mechanical properties. Mechanical characterization of these scaffolds requires establishing the conditions of testing in regard to the conditions set in the bioreactor. The effects of different parameters used during mechanical testing on the collagen gels were evaluated in terms of mechanical and viscoelastic properties. Thus, a factorial experiment was adopted, and three relevant factors were considered: temperature (23°C or 37°C, hydration (aqueous saline solution or air, and mechanical preconditioning (with or without. Statistical analyses showed significant effects of these factors on the mechanical properties which were assessed by tensile tests as well as stress relaxation tests. The last tests provide a more consistent understanding of the gels' viscoelastic properties. Therefore, performing mechanical analyses on hydrogels requires setting an adequate environment in terms of temperature and aqueous saline solution as well as choosing the adequate test.

  12. physico-chemical properties and energy potential of wood wastes

    African Journals Online (AJOL)

    user

    transportation fuels by using several technologies available such as direct combustion, gasification and pyrolysis [9]. Combustion with energy recovery involves the burning of wood wastes and transferring the heat produced to water for the purpose of generating steam in boiler super-heater tubes. The steam may be used to.

  13. Geotechnical Properties of Waste Engine Oil Contaminated Laterites ...

    African Journals Online (AJOL)

    Surface disposal of waste engine oil is common in many parts of Nigeria and this result in the attendant contamination of soils. It is therefore important to investigate the effect of this on laterites which are commonly used as bases for road construction. In this work, laboratory tests were performed on four lateritic soils ...

  14. Antioxidative properties of some phototropic microalgae grown in waste water

    DEFF Research Database (Denmark)

    Safafar, Hamed; Jacobsen, Charlotte; Møller, Peter

    for the screening and selection of the species. In this study,the potential antioxidant activities of 12 micro algal sample from Chlorella., Spirulina., Euglena, Scenedesmus and Haematococcus species grown in waste water in Kalundborg micro algal facilities were evaluated using three antioxidant assays, including...

  15. Physico-chemical properties and energy potential of wood wastes ...

    African Journals Online (AJOL)

    Calorific values, moisture contents as well as proximate and ultimate analyses were performed to assess the energy characteristics of the collected wood wastes in accordance with the American Society for Testing and Materials: ASTM E872-82 and ASTM D4442-07. Results from the laboratory experiments and energy ...

  16. Ipe: Evaluation of orthotropic elastic properties and its application in roadside barriers

    Science.gov (United States)

    Lankford, Robert

    Roadside barriers are the primary structural safety device on surface roads. They can be made from any material as long as they can absorb the energy involved in an impact scenario. One material that has that potential is Ipe. Ipe is a hardwood material that has relatively high strength compared to common structural woods. Despite its high strength, the 9 independent material properties for Ipe has not studied in the literature. In this paper, those material properties are determined with various tests. With the material properties, dynamic finite element analyses were done with seven different roadside barrier configurations and were then compared to the performance of the commonly used steel W-beam barrier. Ipe showed great potential with certain configurations, but with a much higher cost. Realistic implementation of Ipe in roadside barriers would be more beneficial for roads with lower speed limits, thus lowering that cost.

  17. Predictive analysis of chitosan-based nanocomposite biopolymers elastic properties at nano- and microscale.

    Science.gov (United States)

    Kossovich, Elena L; Safonov, Roman A

    2016-04-01

    Chitosan nanocomposites mechanical properties play a major role in usage of such materials for specific areas of application, mostly in medicine and development of ecologically-friendly production. Computer-based predictive modelling of such composites will reduce costs of their development. In this paper, a multiscale approach for structural characterization and evaluation of mechanical properties is proposed based on hybrid coarse-grained/all atom molecular dynamics. Chitosan films and fibers are constructed and studied in silico as well as chitosan composites with different types of randomly distributed reinforcing fillers (graphene nanoparticles, graphene oxide nanoparticles, carbon nanotubes, chitin nanoparticles). Young's moduli are found for such composites, degrees of improvement of mechanical properties and size effects within the framework of proposed methodology are discussed.

  18. An Ab-initio study of structural, elastic, electronic and thermodynamic properties of triclinic Cu{sub 7}In{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ching-Feng [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Cheng, Hsien-Chie, E-mail: hccheng@fcu.edu.tw [Department of Aerospace and Systems Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Chen, Wen-Hwa, E-mail: whchen@pme.nthu.edu.tw [Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2016-05-01

    First principles density functional theory calculations within the generalized gradient approximation are performed to comprehensively study the structural, elastic, electronic and thermodynamic properties of triclinic single and polycrystalline Cu{sub 7}In{sub 3}. The polycrystalline elastic properties are predicted using the Voigt–Reuss–Hill approximation and the thermodynamic properties are evaluated based on the quasi-harmonic Debye model. Their temperature, hydrostatic pressure or crystal orientation dependences are also addressed, and the predicted physical properties are compared with the literature experimental and theoretical data and also with those of three other Cu–In compounds, i.e., CuIn, Cu{sub 2}In and Cu{sub 11}In{sub 9}. The present calculations show that in addition to being a much better conductor compared to Cu{sub 2}In and Cu{sub 11}In{sub 9}, Cu{sub 7}In{sub 3} crystal reveals weak elastic anisotropy, high ductility and low stiffness, and tends to become more elastically isotropic at very high hydrostatic pressure. Moreover, the Cu{sub 7}In{sub 3} holds the largest high-temperature heat capacity among the four Cu–In compounds. - Highlights: • The physical property of Cu{sub 7}In{sub 3} is reported by first-principles calculations. • Pressure effect on the physical property of Cu{sub 7}In{sub 3} is presented. • The calculated lattice constants of Cu{sub 7}In{sub 3} agree well with the experimental data. • Cu{sub 7}In{sub 3} tends to become more elastically isotropic at very high pressure. • The heat capacity of Cu{sub 7}In{sub 3} is much larger than that of CuIn, Cu{sub 2}In and Cu{sub 11}In{sub 9}.

  19. Effect of ordered B-site cations on the structure, elastic and thermodynamic properties of KTa0.5Nb0.5O3 crystal

    Science.gov (United States)

    Yang, Wenlong; Han, Junsheng; Wang, Li; Shen, Yanqing; Li, Linjun; Yang, Yuqiang; Li, Haidong; Chen, Liangyu

    2017-07-01

    BO6 oxygen octahedral was considered as the key part in ABO3 perovskite structure, and the electro-optical, elastic and thermodynamic properties of potassium tantalate niobate (KTa0.5Nb0.5O3, abbreviated as KTN) were closely depended on the B-site Ta/Nb ratio and ordering. The effect of [100]NT, [110]NT, and [111]NT B-site cations ordering (N means a pure Nb layer parallel to ( h, k, l), T means a pure Ta layer parallel to ( h, k, l)) on structure, elastic properties and Debye temperatures properties of KTN were investigated based on density functional theory (DFT). KTN with [111]NT B-site ordering presents an cubic phase structure with excellent stability from the view of lattice properties. The elastic properties include elastic stiffness coefficients C ij , bulk modulus B, shear modulus G, Young's modulus E and Poisson' ratio ν were calculated. The elastic stiffness coefficients C 11 of KTN with B-site ordering have approached to maximum 485.506 GPa, indicating that KTN materials have better deformation ability along x axis compared with other perovskite materials. The calculated results of bulk modulus B and the shear modulus G show that KTN with [100]NT B-site ordering has stronger ability to resist fracture and plastic deformation. And the criteria B/G <1.75 suggests that KTN should be classified as a brittle material. The KTN with [100]NT B-site has excellent ductility properties compared with any other B-site arrangements. Debye temperatures of KTN with [100]NT, [110]NT, [111]NT are about 650 K, and KTN with [100]NT B-site has best thermodynamic stability.

  20. Density functional study of elastic and vibrational properties of the Heusler-type alloys Fe2VAl and Fe2VGa

    DEFF Research Database (Denmark)

    Kanchana, V.; Vaitheeswaran, G.; Ma, Yanming

    2009-01-01

    The structural and elastic properties as well as phonon-dispersion relations of the Heusler-type alloys Fe2VAl and Fe2VGa are computed using density functional and density-functional perturbation theory within the generalized-gradient approximation. The calculated equilibrium lattice constants...

  1. Effect of different RE site ionic radii on the electronic structures and elastic properties of Ba2RENbO6: A first-principles study

    Science.gov (United States)

    Du, Lifei; Zhang, Peng; Wang, Lianli; Du, Huiling

    2017-09-01

    RE site ionic radius has a critical influence on the properties of double perovskite oxide Ba2RENbO6. In this paper, the electronic structures and elastic properties of Ba2RENbO6 (RE = Ho, Er, Yb) have been calculated by using the plane-wave pseudopotential density functional theory, and the effect of the different RE site ions on the structures and properties of Ba2RENbO6 is discussed. Results indicate that Ba2RENbO6 (RE = Ho, Er, Yb) are all direct bandgap semiconductors with a bandgap of 0.95 eV, 1.26 eV and 2.36 eV, respectively. With the decrease of the RE site ionic radius of Ba2RENbO6 (RE = Ho, Er, Yb), RE-O and Nb-O covalent bonds are enhanced, and the elastic constants (c11, c12, c44), elastic modulus (B, G, Y), B/G, Poisson’s ratio (σ), the Debye temperature Θ, Gruneisen parameters ζ all show a trend of increase. The elastic and thermodynamic properties are all improved with the decreasing radius of RE site ion.

  2. Pressure dependence of elastic properties of ZnX (X= Se, S and Te ...

    Indian Academy of Sciences (India)

    An effective interaction potential (EIOP) is developed to invoke the pressure induced phase transition from zinc blende (3) to rocksalt (1) structure and anharmonic properties in ZnX (X = Se, S, Te) semiconductors. The effective interaction potential incorporates the long range Coulomb interaction, van der Waals ...

  3. Characterization of Elastic Properties of Porous Graphene Using an Ab Initio Study

    Directory of Open Access Journals (Sweden)

    Reza Ansari

    2016-12-01

    Full Text Available Importance of covalent bonded two-dimensional monolayer nanostructures and also hydrocarbons is undeniably responsible for creation of new fascinating materials like polyphenylene polymer, a hydrocarbon super honeycomb network, so-called porous graphene. The mechanical properties of porous graphene such as its Young’s modulus, Poisson’s ratio and the bulk modulus as the determinative properties are calculated in this paper using ab initio calculations. To accomplish this aim, the density functional theory on the basis of generalized gradient approximation and the Perdew–Burke–Ernzerhof exchange correlation is employed. Density functional theory calculations are used to calculate strain energy of porous graphene with respect to applied strain. Selected numerical results are then presented to study the properties of porous graphene. Comparisons are made between the properties of porous graphene and those of other analogous nanostructures. The results demonstrated lower stiffness of porous graphene than those of graphene and graphyne, and higher stiffness than that of graphdyine and other graphyne families. Unlikely, Poisson’s ratio is observed to be more than that of graphene and also less than that of graphyne. It is further observed that the presence of porosity and also formation of C-H bond in the pore sites is responsible for these discrepancies. Porous graphene is found to behave as the isotropic material.

  4. Tribo-charging properties of waste plastic granules in process of tribo-electrostatic separation.

    Science.gov (United States)

    Li, Jia; Wu, Guiqing; Xu, Zhenming

    2015-01-01

    Plastic products can be found everywhere in people's daily life. With the consistent growth of plastic consumption, more and more plastic waste is generated. Considering the stable chemical and physics characteristics of plastic, regular waste management methods are not suitable for recycling economic strategy of each government, which has become a serious environmental problem. Recycling plastic waste is considered to be the best way to treat it, because it cannot only deduce the waste but also save the energy to produce new virgin plastic. Tribo-electrostatic separation is strongly recommended for plastic separation as it can preserve the original properties of plastic and has little additional pollution. In this study, plastic granules are generated by crushing plastic waste in waste electric and electronic equipment. The tribo-charging properties of plastic waste were studied by vibrating tribo-charging and cyclone tribo-charging. The triboelectric series obtained by vibrating was: (-)-PE-PS-PC-PVC-ABS-PP-(+), while the triboelectric series obtained by cyclone was (-)-PE-PS-PC-PVC-ABS-PP-(+). Further, the cyclone charging was more effective and stable than vibrating charging. The impact factors experiments showed that small particle size was better changed than large ones and were more suitable recycled by tribo-electrostatic separation. High relative humidity was identified as impede charging effect. The results of this study will help defining the operating parameters of subsequent separator. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Evaluation of transport properties of nanofiltration membranes exposed to radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Elizabeth E.M.; Barbosa, Celina C.R.; Bastos, Edna T.R., E-mail: eemo@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeira, RJ (Brazil); Afonso, Julio C., E-mail: Julio@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2011-07-01

    The application of membrane separation processes (PSM) for treatment of radioactive waste requires the selection of a suitable membrane for the treatment of waste, as the membrane will be directly exposed to the radioactive liquid waste, and also exposed to ionizing radiation. The nanofiltration membrane is most suitable for treatment of radioactive waste, since it has high rejection of multivalent ions. Usually the membranes are made of polymers and depending on the composition of the waste, type and dose of radiation absorbed may be changes in the structure of the membrane, resulting in loss of its transport properties. We tested two commercial nanofiltration membranes: NF and SW Dow/Filmtec. The waste liquid used was obtained in the process of conversion of uranium hexafluoride gas to solid uranium dioxide, known as 'carbonated water'. The membranes were characterized as their transport properties (hydraulic permeability, permeate flux and salt rejection) before and after their immersion in the waste for 24 hours. The surface of the membranes was also evaluated by SEM and FTIR. It was observed that in both the porosity of the membrane selective layer was altered, but not the membrane surface charge, which is responsible for the selectivity of the membrane. The NF membranes and SW showed uranium ion rejection of 64% and 55% respectively. (author)

  6. Physical and mechanical properties of quarry dust waste incorporated into fired clay brick

    Science.gov (United States)

    Kadir, A. A.; Hassan, M. I. H.; Sarani, N. A.; Rahim, A. S. Abdul; Ismail, N.

    2017-04-01

    A large amount of quarry dust waste is dispose into landfills every year. This waste was obtained as a by-product during the production of aggregates through the crushing process of rocks in rubble crusher units. The increasing value of waste will have significant impact towards health and environment. Recycling such wastes by incorporating them into building materials is a practical solution for pollution problem. Therefore, this research was to examine the possibility of quarry dust to be incorporated in fired clay bricks. In this research, the composition and concentration of heavy metals were determined by using X-Ray Fluorescence Spectrometer (XRF). The research also consists of physical and mechanical properties of the fired clay bricks by utilizing quarry dust waste. Brick was manufactured by incorporating different percentages of quarry dust waste which are 0%, 10%, 20% and 30%. All bricks sample was tested with physical and mechanical properties which were density, shrinkage, initial rate of suction (IRS) and compressive strength of the fired bricks. Furthermore, the density and shrinkage were also in standard range. All physical and mechanical results were complied with the BS 3921:1985 standard. The comprehensive experimental work described in this research investigated the possibility of incorporating quarry dust into fired clay bricks. These materials could be an alternative low cost material for brick and at the same time provide a new disposal method for the waste.

  7. Mechanical properties of structural lightweight concrete reinforced with waste steel wires

    OpenAIRE

    Aghaee, K; Yazdi, MA; Tsavdaridis, KD

    2014-01-01

    The study of concrete incorporating different waste fibres has started to increase rapidly due to economic reasons and positive environmental effects. In the study reported here, waste steel wires from steel reinforcement and used formworks were blended with structural lightweight concrete, with the aim of replacing commercial steel fibres of controlled quality with recycled fibres. Compression, tensile, flexural and impact tests were performed to assess the mechanical properties of 28 d old ...

  8. A Preliminary Study on Light Transmittance Properties of Translucent Concrete Panels with Coarse Waste Glass Inclusions

    OpenAIRE

    Lo Verso, Valerio Roberto Maria; Torta, Annalisa; Pagliolico, Simonetta Lucia

    2015-01-01

    This paper investigates the potential reuse of coarse glass wastes as insert in a high performance cement matrix to produce translucent concrete panels for architectural applications such as interior walls. The effects of the addition of glass scraps on chemical and optical properties of concrete were studied. Alkali-silica reactivity resistance tests were carried out to evaluate the reactivity between amorphous waste glass and alkaline concrete pore solution. Light transmittance LT was evalu...

  9. Enhancement of concrete properties for pavement slabs using waste metal drillings and silica fume.

    Science.gov (United States)

    Hassani, Abolfazl; Arjmandi, Mohsen

    2010-01-01

    This paper presents a comparative study on the effects of steel fibres and waste metal drillings on the mechanical/physical behaviour of conventional and silica fume concrete. The amount of silica fume used was 10% of cement by mass and the amount of steel fibres and metal drillings used in both concrete mixtures was 0.5% by concrete volume for steel fibres and 0.0, 0.25, 0.50 and 0.75% for metal drillings, respectively. In total, 10 different mixtures were made and tested for compressive strength, modulus of elasticity, flexural strength and toughness. Our data reveal the significant impact of the effect of silica fume, steel fibres and industrial waste metal drillings on the mechanical and physical characteristics of concrete mixtures. The results also show that mixtures with steel fibres and waste metal drillings have comparable behaviour. Hence, there is a potential for use of waste metal drillings as an alternative to steel fibres for specific cases such as concrete pavement slabs.

  10. Solid waste disposal in the soil: effects on the physical, chemical, and organic properties of soil

    Directory of Open Access Journals (Sweden)

    Vanessa Regina Lasaro Mangieri

    2015-04-01

    Full Text Available Currently, there is growing concern over the final destination of the solid waste generated by society. Landfills should not be considered the endpoint for substances contained or generated in solid waste. The sustainable use of natural resources, especially soil and water, has become relevant, given the increase in anthropogenic activities. Agricultural use is an alternative to solid waste (leachate, biosolid disposal, considering the hypothesis that the agricultural use of waste is promising for reducing waste treatment costs, promoting nutrient reuse and improving the physical and chemical conditions of soil. Thus, this literature review, based on previously published data, seeks to confirm or disprove the hypothesis regarding the promising use of solid waste in agriculture to decrease the environmental liability that challenges public administrators in the development of efficient management. The text below addresses the following subtopics after the introduction: current solid waste disposal and environmental issues, the use of solid waste in agriculture, and the effect on the physical and chemical properties of soil and on organic matter, ending with final considerations.

  11. Effect of elastic and plastic tensile mechanical loading on the magnetic properties of NGO electrical steel

    Science.gov (United States)

    Leuning, N.; Steentjes, S.; Schulte, M.; Bleck, W.; Hameyer, K.

    2016-11-01

    The magnetic properties of non-grain-oriented (NGO) electrical steels are highly susceptible to mechanical stresses, i.e., residual, external or thermal ones. For rotating electrical machines, mechanical stresses are inevitable and originate from different sources, e.g., material processing, machine manufacturing and operating conditions. The efficiency and specific losses are largely altered by different mechanical stress states. In this paper the effect of tensile stresses and plastic deformations on the magnetic properties of a 2.9 wt% Si electrical steel are studied. Particular attention is paid to the effect of magnetic anisotropy, i.e., the influence of the direction of applied mechanical stress with respect to the rolling direction. Due to mechanical stress, the induced anisotropy has to be evaluated as it is related to the stress-dependent magnetostriction constant and the grain alignment.

  12. ENHANCING OF WOOD CHIPPING CONCRETE PROPERTIES BY ADDING WASTE FIBRE

    Directory of Open Access Journals (Sweden)

    Fadia S. Kulak

    2013-05-01

    Full Text Available The recycling of wood chippings, anindustrial waste product, has a potential use in the production of alightweight concrete. In modern countries, the low cost and the proximity ofsupply makes this material a good candidate for local building applications.This study aims to examining the ability of enhancing of a wood fibre lightweightconcrete strength by reinforcing it with lathe scrap from lathe industry. Specimenshave been casted, compressive and split tensile strengths were measured inaddition to the wet and dry weight as per relevant British standardspecifications. The wood chippings are saturated with a water for 24 hours,this is to prevent chippings from sorption the water of the mixture. Testresults indicate that addition of waste fibre from lathe enhances the strengthmarkedly and in the same time increases the weight.

  13. Synthesis, electronic structure, elastic properties, and interfacial behavior of icosahedral boron-rich solids

    OpenAIRE

    Hunold, Oliver

    2017-01-01

    Boron-rich solids are commonly characterized by icosahedral clusters, where 12 B atoms form an icosahedron, giving rise to outstanding mechanical and transport properties. However, broader applications are limited due to the high synthesis temperature required to obtain the icosahedra-based crystalline structure. Utilizing high power pulsed magnetron sputtering (HPPMS), the deposition temperature may be lowered as compared to direct current magnetron sputtering by enhanced surface diffusion. ...

  14. Fluorogel Elastomers with Tunable Transparency, Elasticity, ShapeMemory, and Antifouling Properties**

    Energy Technology Data Exchange (ETDEWEB)

    Yao, X; Dunn, SS; Kim, P; Duffy, M; Alvarenga, J; Aizenberg, J

    2014-03-18

    Omniphobic fluorogel elastomers were prepared by photocuring perfluorinated acrylates and a perfluoropolyether crosslinker. By tuning either the chemical composition or the temperature that control the crystallinity of the resulting polymer chains, a broad range of optical and mechanical properties of the fluorogel can be achieved. After infusing with fluorinated lubricants, the fluorogels showed excellent resistance to wetting by various liquids and anti-biofouling behavior, while maintaining cytocompatiblity.

  15. Fluorogel Elastomers with Tunable Transparency, Elasticity, Shape-Memory, and Antifouling Properties**

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Xi; Dunn, Stuart; Kim, Philseok; Duffy, Meredith; Alvarenga, Jack; Aizenberg, Joanna

    2014-04-22

    Omniphobic fluorogel elastomers were prepared by photocuring perfluorinated acrylates and a perfluoropolyether crosslinker. By tuning either the chemical composition or the temperature that control the crystallinity of the resulting polymer chains, a broad range of optical and mechanical properties of the fluorogel can be achieved. After infusing with fluorinated lubricants, the fluorogels showed excellent resistance to wetting by various liquids and anti-biofouling behavior, while maintaining cytocompatiblity.

  16. Bioinspired pH and magnetic responsive catechol-functionalized chitosan hydrogels with tunable elastic properties.

    Science.gov (United States)

    Ghadban, Ali; Ahmed, Anansa S; Ping, Yuan; Ramos, Ricardo; Arfin, Najmul; Cantaert, Bram; Ramanujan, Raju V; Miserez, Ali

    2016-01-14

    We have developed pH- and magnetic-responsive hydrogels that are stabilized by both covalent bonding and catechol/Fe(3+) ligands. The viscoelastic properties of the gels are regulated by the complexation valence and can be used to tune drug release profiles. The stable incorporation of magnetic nanoparticles further expands control over the mechanical response and drug release, in addition to providing magnetic stimuli-responsivity to the gels.

  17. Effect of freezing storage time on the elastic and viscous properties of the porcine TMJ disc.

    Science.gov (United States)

    Calvo-Gallego, Jose L; Commisso, Maria S; Domínguez, Jaime; Tanaka, Eiji; Martínez-Reina, Javier

    2017-07-01

    The correct characterisation of the articular disc of the temporomandibular joint (TMJ) is key to study the masticatory biomechanics. For the interval from extraction until testing, freezing is the most used preservation technique for biological tissues, but its influence on their behaviour is still unclear. An important error can be committed in the characterisation of such tissues if freezing has any effect on their mechanical properties. Thus, the aim of this study was to determine whether the freezing storage time causes any change in the mechanical properties of the TMJ discs. To check that, the specimens were stored in a -20°C freezer during different time intervals: 1 day, 1 week, 1 month and 3 months. Fresh specimens, tested right after extraction, were used as the control group. Compressive stress relaxation tests were carried out on the specimens and a quasi-linear viscoelastic (QLV) model was used to fit the experimental curves. A statistical analysis detected significant differences among the groups. Post-hoc tests determined that freezing the specimens more than 30 days may lead to changes in the viscoelastic properties of the tissue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Thermodynamic parameters of elasticity and electrical conductivity ...

    African Journals Online (AJOL)

    The thermodynamic parameters (change in free energy of elasticity, DGe; change in enthalpy of elasticity, DHe; and change in entropy of elasticity, DSe) and the electrical conductivity of natural rubber composites reinforced separately with some agricultural wastes have been determined. Results show that the reinforced ...

  19. Modeling elastic and thermal properties of 2.5D carbon fiber and carbon/SiC hybrid matrix composites by homogenization method

    OpenAIRE

    Luiz Claudio Pardini; Maria Luisa Gregori

    2010-01-01

    Abstract: Advanced carbon fiber hybrid carbon-ceramic matrix composites are realizing their potential in many thermostructural components for aerospace vehicles. This work presents ab-initio predictions of elastic constants and thermal properties for 2.5D carbon fiber reinforced carbon-silicon carbide hybrid matrix composites, by using the homogenization technique. The homogenization technique takes properties of individual components of the composites (fiber and matrix) and characteristics o...

  20. Elasticity of polymeric nanocolloidal particles

    National Research Council Canada - National Science Library

    Riest, Jonas; Athanasopoulou, Labrini; Egorov, Sergei A; Likos, Christos N; Ziherl, Primož

    2015-01-01

    .... Elasticity of individual particles directly controls their swelling, wetting, and adsorption behaviour, their aggregation and self-assembly as well as structural and rheological properties of suspensions...

  1. The structural, elastic, electronic and dynamical properties of chalcopyrite semiconductor BeGeAs{sub 2} from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Ciftci, Yasemin Oe. [Gazi University Teknikokullar, Department of Physics, Faculty of Sciences, Ankara (Turkey); Evecen, Meryem; Aldirmaz, Emine [Amasya University, Department of Physics, Faculty of Arts and Sciences, Amasya (Turkey)

    2017-01-15

    First-principles calculations for the structural, elastic, electronic and vibrational properties of BeGeAs{sub 2} with chalcopyrite structure have been reported in the frame work of the density functional theory. The calculated ground state properties are in good agreement with the available data. By considering the electronic band structure and electronic density of states calculation, it is found that this compound is a semiconductor which confirmed the previous work. Single-crystal elastic constants and related properties such as Young's modulus, Poisson ratio, shear modulus and bulk modulus have been predicted using the stress-finite strain technique. It can be seen from the calculated elastic constants that this compound is mechanically stable in the chalcopyrite structure. Pressure dependences of elastic constants and band gap are also reported. Finally, the phonon dispersion curves and total and partial density of states were calculated and discussed. The calculated phonon frequencies BeGeAs{sub 2} are positive, indicating the dynamical stability of the studied compound. (orig.)

  2. Comparative study on structural, elastic, dynamical, and thermodynamic properties of Weyl semimetals MX (M = Ta or Nb; X = As or P)

    Science.gov (United States)

    Liu, Lei; Wang, Zhao-Qi; Hu, Cui-E.; Cheng, Yan; Ji, Guang-Fu

    2017-09-01

    We present a comparative investigation on structural, elastic, dynamical and thermodynamic properties of Weyl semimetals MX (M = Ta or Nb; X = As or P) using density functional theory (DFT) within the generalized gradient approximation. The elastic properties of NbAs, TaP and NbP are obtained for the first time, then we compared them with each other and with some well-studied materials. Among four Weyl semimetals, TaP and NbAs possess the largest and smallest bulk modulus B, shear modulus G, and Young's modulus E, respectively, while NbP and TaAs own the maximum and minimum elastic Debye temperature. Through the analysis of three dimensional (3D) representations and two dimensional (2D) projections of Young's modulus, MX series exhibit distinct elastic anisotropy, especially for TaAs and NbAs. The calculated phonon dispersions of four Weyl semimetals show no imaginary frequency throughout the Brillouin zone, indicating they are dynamically stable. In addition, compared with other theoretical results, our calculated Brillouin-zone-center frequencies of MX series are more in line with experimental data. Furthermore, Phonon velocities are obtained using phonon spectra, and anisotropic phonon group velocities are responsible for their anisotropic lattice thermal conductivity. Additionally, thermodynamic properties are also predicted using the calculated phonon density of states. The results are in good agreement with available experimental values. We expect our work can provide more information for further experimental studies.

  3. Tl{sub 4}CdI{sub 6} – Wide band gap semiconductor: First principles modelling of the structural, electronic, optical and elastic properties

    Energy Technology Data Exchange (ETDEWEB)

    Piasecki, M., E-mail: m.piasecki@ajd.czest.pl [Institute of Physics, Jan Dlugosz University, Armii Krajowej 13/15, 42-200 Czestochowa (Poland); Brik, M.G. [College of Sciences, Chongqing University of Posts and Telecommunications, Chongqing 400065 (China); Institute of Physics, University of Tartu, Ravila 14C, Tartu 50411 (Estonia); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Kityk, I.V. [Faculty of Electrical Engineering, Czestochowa University of Technology, Armii Krajowej 17, 42-200 Czestochowa (Poland)

    2015-08-01

    A novel infrared optoelectronic material Tl{sub 4}CdI{sub 6} was studied using the density functional theory (DFT)-based techniques. Its structural, electronic, optical and elastic properties were all calculated in the generalized gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE) and the local density approximation (LDA) with the Ceperley-Alder–Perdew-Zunger (CA–PZ) functionals. The studied material is a direct band gap semiconductor with the calculated band gaps of 2.043 eV (GGA) and 1.627 eV (LDA). The wavelength dependence of the refractive index was fitted to the Sellmeier equation in the spectral range from 400 to 2000 nm. Good agreement between the GGA-calculated values of refractive index and experimental data was achieved. To the best of our knowledge, this is the first consistent theoretical description of the title compound, which includes calculations and analysis of the structural, electronic, optical and elastic properties. - Graphical abstract: Display Omitted - Highlights: • Infrared optoelectronic material Tl{sub 4}CdI{sub 6} was studied using ab initio methods. • Structural, electronic, optical and elastic properties were calculated. • Independent components of the elastic constants tensor were calculated. • Good agreement with available experimental results was achieved.

  4. Investigation of structural, electronic and anisotropic elastic properties of Ru-doped WB{sub 2} compound by increased valence electron concentration

    Energy Technology Data Exchange (ETDEWEB)

    Surucu, Gokhan, E-mail: g_surucu@yahoo.com [Ahi Evran University, Department of Electric and Energy, 40100, Kirsehir (Turkey); Gazi University, Photonics Application and Research Center, 06500, Ankara (Turkey); Kaderoglu, Cagil [Ankara University, Department of Engineering Physics, 06100, Ankara (Turkey); Deligoz, Engin; Ozisik, Haci [Aksaray University, Department of Physics, 68100, Aksaray (Turkey)

    2017-03-01

    First principles density functional theory (DFT) calculations have been used to investigate the structural, anisotropic elastic and electronic properties of ruthenium doped tungsten-diboride ternary compounds (W{sub 1−x}Ru{sub x}B{sub 2}) for an increasing molar fraction of Ru atom from 0.1 to 0.9 by 0.1. Among the nine different compositions, W{sub 0.3}Ru{sub 0.7}B{sub 2} has been found as the most stable one due to the formation energy and band filling theory calculations. Moreover, the band structures and partial density of states (PDOS) have been computed for each x composition. After obtaining the elastic constants for all x compositions, the secondary results such as Bulk modulus, Young’s modulus, Poisson’s ratio, Shear modulus, and Vickers Hardness of polycrystalline aggregates have been derived and the relevant mechanical properties have been discussed. In addition, the elastic anisotropy has been visualized in detail by plotting the directional dependence of compressibility, Poisson ratio, Young’s and Shear moduli. - Highlights: • Effects of Ru substitution in WB{sub 2} using increased valence electron concentration. • Structural, electronic, mechanic and elastic properties for increasing Ru content. • Considered alloys are incompressible, brittle, stiffer and high hard materials.

  5. Modeling the Effect of Helical Fiber Structure on Wood Fiber Composite Elastic Properties

    Science.gov (United States)

    Marklund, Erik; Varna, Janis

    2009-08-01

    The effect of the helical wood fiber structure on in-plane composite properties has been analyzed. The used analytical concentric cylinder model is valid for an arbitrary number of phases with monoclinic material properties in a global coordinate system. The wood fiber was modeled as a three concentric cylinder assembly with lumen in the middle followed by the S3, S2 and S1 layers. Due to its helical structure the fiber tends to rotate upon loading in axial direction. In most studies on the mechanical behavior of wood fiber composites this extension-twist coupling is overlooked since it is assumed that the fiber will be restricted from rotation within the composite. Therefore, two extreme cases, first modeling fiber then modeling composite were examined: (i) free rotation and (ii) no rotation of the cylinder assembly. It was found that longitudinal fiber modulus depending on the microfibril angle in S2 layer is very sensitive with respect to restrictions for fiber rotation. In-plane Poisson’s ratio was also shown to be greatly influenced. The results were compared to a model representing the fiber by its cell wall and using classical laminate theory to model the fiber. It was found that longitudinal fiber modulus correlates quite well with results obtained with the concentric cylinder model, whereas Poisson’s ratio gave unsatisfactory matching. Finally using typical thermoset resin properties the longitudinal modulus and Poisson’s ratio of an aligned softwood fiber composite with varying fiber content were calculated for various microfibril angles in the S2 layer.

  6. Woven glass fabric reinforced laminates based on polyolefin wastes: Thermal, mechanical and dynamic-mechanical properties

    Science.gov (United States)

    Russo, Pietro; Acierno, Domenico; Simeoli, Giorgio; Lopresto, Valentina

    2014-05-01

    Potentialities of polyolefin wastes in place of virgin polypropylene to produce composite laminates have been investigated. Plaques reinforced with a woven glass fabric were prepared by film-stacking technique and systematically analyzed in terms of thermal, mechanical and dynamic-mechanical properties. In case of PP matrices, the use of a typical compatibilizer to improve the adhesion at the interface has been considered. Thermal properties emphasized the chemical nature of plastic wastes. About mechanical properties, static tests showed an increase of flexural parameters for compatibilized systems due to the coupling effect between grafted maleic anhydride and silane groups on the surface of the glass fabric. These effects, maximized for composites based on car bumper wastes, is perfectly reflected in terms of storage modulus and damping ability of products as determined by single-cantilever bending dynamic tests.

  7. X-ray spectra and theoretical elastic properties of crystalline calcium silicate hydrates: comparison with cement hydrated gels

    Directory of Open Access Journals (Sweden)

    Ayuela, A.

    2010-09-01

    Full Text Available For 22 crystalline Calcium Silicates Hydrates, we have calculated their structure and their elastic properties by atomistic force field methods as well as simulate their Xray diffraction patterns. From the computed Young moduli, it can be suggested that the key parameters to determine the elastic properties of crystalline Calcium Silicate Hydrates are densities and water content. We have compared these trends with those of cementitious C-S-H gel and synthetic C-S-H type I as a function of their C/S ratios and nominal water content. Our comparison show that the experimentally suggested values of density and Young moduli for C-S-H gel lie in the range of the calculated CSH crystals. However, we conclude that a detailed correspondence might require investigating structurally within CSH gels the role of water and especially of Ca and Si sites through their C/S ratio.

    En este trabajo se han calculado para 22 Silicatos Cálcicos Hidratados cristalinos, su estructura y sus propiedades elásticas mediante métodos atomísticos “force field”, así como simulado sus espectros de difracción de rayos X. De los módulos de Young calculados se puede deducir, que los parámetros clave que determinan las propiedades elásticas de los Silicatos Cálcicos Hidratados cristalinos son la densidad y el contenido en agua. Nuestros resultados muestran que los valores experimentales de la densidad y de los módulos de Young para el gel C-S-H están dentro del rango de los cristales de CSH calculados. Sin embargo, podemos concluir que para establecer una correlación más directa sería necesario investigar el papel que juegan el agua y sobre todo el Ca y Si, mediante la relación C/S, en la estructura del gel CSH.

  8. Rietveld structure refinement and elastic properties of MgAlxCrxFe2-2xO4 spinel ferrites

    Science.gov (United States)

    Thummer, K. P.; Tanna, Ashish R.; Joshi, Hiren H.

    2017-05-01

    MgAlxCrxFe2-2xO4 (x = 0.1, 03 & 0.6) ferrites are synthesized by solid state reaction method. The Rietveld refinement of X-ray diffraction (XRD) data confirms the cubic spinel structure with Fd3m space group. The Fourier Transform Infrared Transmission Spectroscopy (FTIR) is employed to study elastic properties of present systems at 300K. The force constants for tetrahedral (A) and octahedral (B) sites of the spinel lattice are determined by infrared spectral and X-ray diffraction analysis. The elastic constants like bulk modulus, rigidity modulus, Young's modulus, Poisson's ratio and Debye temperature are determined. The vibrational frequency of both the interstitial sites increases as Al-Cr content increases hence the force constant and elastic moduli for all the samples are found to increase for the present ferrite system.

  9. Ab Initio Predicted Alloying Effects on the Elastic Properties of AlxHf1−xNbTaTiZr High Entropy Alloys

    Directory of Open Access Journals (Sweden)

    Shaohui Li

    2015-07-01

    Full Text Available Using ab initio alloy theory, we investigate the equilibrium bulk properties and elastic mechanics of the single bcc solid-solution AlxHf1−xNbTaTiZr (x = 0–0.7, 1.0 high entropy alloys. Ab initio predicted equilibrium volume is consistent with the available experiment. We make a detailed investigation of the alloying effect of Al and Hf on the equilibrium volume, elastic constants and polycrystalline elastic moduli. Results imply that the partial replacement Hf with Al increases the stability of the bcc phase and decreases the ductility of the AlxHf1−xNbTaTiZr HEAs. The inner ductility of Al0.4Hf0.6NbTaTiZr is predicted by the calculations of ideal tensile strength.

  10. Anomalous elastic properties across the γ to α volume collapse in cerium

    Energy Technology Data Exchange (ETDEWEB)

    Lipp, Magnus J.; Jenei, Zs.; Cynn, H.; Kono, Y.; Park, C.; Kenney-Benson, C.; Evans, W.J. (LLNL); (CIW)

    2017-10-31

    The behavior of the f-electrons in the lanthanides and actinides governs important macroscopic properties but their pressure and temperature dependence is not fully explored. Cerium with nominally just one 4f electron offers a case study with its iso-structural volume collapse from the γ-phase to the α-phase ending in a critical point (pC, VC, TC), unique among the elements, whose mechanism remains controversial. Here, we present longitudinal (cL) and transverse sound speeds (cT) versus pressure from higher than room temperature to TC for the first time. While cL experiences a non-linear dip at the volume collapse, cT shows a step-like change. This produces very peculiar macroscopic properties: the minimum in the bulk modulus becomes more pronounced, the step-like increase of the shear modulus diminishes and the Poisson’s ratio becomes negative—meaning that cerium becomes auxetic. At the critical point itself cerium lacks any compressive strength but offers resistance to shear.

  11. Chemically cross-linked silk fibroin hydrogel with enhanced elastic properties, biodegradability, and biocompatibility.

    Science.gov (United States)

    Kim, Min Hee; Park, Won Ho

    2016-01-01

    In this study, the synthesis of silk fibroin (SF) hydrogel via chemical cross-linking reactions of SF due to gamma-ray (γ-ray) irradiation was investigated, as were the resultant hydrogel's properties. Two different hydrogels were investigated: physically cross-linked SF hydrogel and chemically cross-linked SF hydrogel irradiated at different doses of γ-rays. The effects of the irradiation dose and SF concentration on the hydrogelation of SF were examined. The chemically cross-linked SF hydrogel was compared with the physically cross-linked one with regard to secondary structure and gel strength. Furthermore, the swelling behavior, crystallinity, and biodegradation of the SF hydrogels were characterized. To assay cell proliferation, the cell viability of human mesenchymal stem cells on the lyophilized SF hydrogel scaffolds was evaluated, and no significant cytotoxicity against human mesenchymal stem cells was observed.

  12. Effect of the addition of fibreglass waste on the properties of dried and fired clay bricks

    Science.gov (United States)

    Guzlena, S.; Sakale, G.; Certoks, S.; Grase, L.

    2017-10-01

    The main objective of this study was to investigate the effect of the addition of fibreglass waste on the properties of the dried and fired clay bricks. Different amounts of waste glass (0 – 10 wt %) were added to the original brick clay and fired at 1000 °C. The effects on the technological properties of the bricks such as compressive strength, water absorption and density after firing were investigated. Also cracks and fibreglass influence in dried and fired samples were analysed by digital camera and SEM-EDX analysis.

  13. The elastic constants and related properties of the epsilon polymorph of the energetic material CL-20 determined by Brillouin scattering

    Science.gov (United States)

    Haycraft, James J.

    2009-12-01

    The acoustic phonons of the epsilon polymorph of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo [5.5.0.05,9.03,11] dodecane (ɛ-CL-20) have been studied using Brillouin scattering spectroscopy. Analysis of the acoustic phonon velocities allowed determination of the complete stiffness tensor for this energetic material. The results are compared to a theoretical determination of the ɛ-CL-20 elastic constants, bulk moduli, and shear moduli. The observed ordering of elastic constants, C22>C33>C11, is noted to be different from other nitramine energetic materials. Finally, the elasticity of ɛ-CL-20 is compared to recently published reports on cyclotrimethylene trinitramine's (RDX) elasticity and the beta polymorph of cyclotetramethylene tetranitramine's (β-HMX) elasticity.

  14. Analysis of Dielectric Properties On Agricultural Waste for Microwave Communication Application

    Directory of Open Access Journals (Sweden)

    Zulkifli Nurul Ain

    2017-01-01

    Full Text Available This paper presents the analysis of dielectric properties of agricultural waste for microwave communication application such as microwave absorber and antenna. The residues products – rice straw, rice husk, banana leaves and sugar cane bagasse were studied in the range between 1-20GHz. Firstly, the 2 types of resins namely Epoxy der 331 and Polyamine clear hardener were mixed with the agricultural waste materials to produce the small size of agricultural waste sample. Then, the sample were measured using PNA network analyzer. The permittivity and tangent loss of different agricultural waste samples have been measured using dielectric probe technique. Besides, other objectives of this paper is to replace the conventional printed circuit board (PCB using FR4, Taconic, and Roger material with the agricultural waste material. Besides that, the different percentage of filer for each agricultural waste materials were also investigated to specify the best material to be used as the substrate board and as the resonant material. the result shows the average of dielectric constants and the average of the tangent loss of agricultural waste materials.

  15. Electrical, Elastic, and Piezoresistive Properties of Nanocomposites of Poly(dimethylsiloxane) and Poly(phenylmethylsiloxane)-Functionalized Graphene Nanoplatelets

    Science.gov (United States)

    Zhang, Biao; Li, Buyin; Jiang, Shenglin

    2017-10-01

    High-performance piezoresistive materials can detect pressures in the finger-sensing regime (0 kPa to 100 kPa). Piezoresistive nanocomposites of poly(phenylmethylsiloxane) (PPMS)-functionalized graphene nanoplatelets (P-GNPs) as conductive filler and polydimethylsiloxane (PDMS) as polymer matrix have been prepared and their electrical, elastic, and piezoresistive properties investigated. GNPs were π-π stacked with PPMS by noncovalent functionalization, and P-GNPs/PDMS nanocomposites were prepared by solution casting. The results showed that P-GNPs with sandwiched nanostructures (PPMS/GNPs/PPMS) exhibited improved dispersibility and compatibility in the PDMS matrix. Compared with GNPs/PDMS nanocomposites, low percolation threshold (2.96 vol.%) was obtained for the P-GNPs/PDMS nanocomposites. P-GNPs/PDMS nanocomposite with 3.00 vol.% P-GNPs showed remarkable negative piezoresistivity with high sensitivity of -105.22 × 10-3 kPa-1 (0 kPa to 10 kPa), low Young's modulus of 408.26 kPa, and high electrical conductivity of 1.28 × 10-6 S/m. These results demonstrate a simple and low-cost method for preparation of high-performance nanocomposites and facilitate wide application of such piezoresistive materials, especially in cheap and flexible tactile sensors.

  16. Effect of elastic region nanoparticle SiO2 jet polishing on the laser damage properties of fused silica

    Science.gov (United States)

    Song, Jialiang; Shi, Feng; Xiao, Qi; Yang, Ping

    2017-08-01

    To further improve the laser-induced damage threshold of fused silica elements after Hydrogen Fluoride (HF) acid dynamic acid etching, the effect of the nanoparticle SiO2 jet polishing on the surface quality and laser damage properties of fused silica was studied. On the fused silica surface after HF acid dynamic etching, different depths were polished with nanoparticle SiO2 jet, and their surface roughness were measured by In-situ detection. The photothermal absorption, laser damage threshold and surface contamination element concentration at different depths were measured. The experimental results show that the RMS value of the surface roughness of the surface is reduced from 1.440nm to 0.507nm, and surface contamination elements are removed. The laser damage threshold is improved by 10%. The results show that nanoparticle SiO2 jet polishing can remove surface damage and contamination after HF acid dynamic etching on the basis of elastic processing. Therefore, laser damage threshold can be improved.

  17. EFFECTIVE ELASTIC PROPERTIES OF ALUMINA-ZIRCONIA COMPOSITE CERAMICS - PART 4. TENSILE MODULUS OF POROUS ALUMINA AND ZIRCONIA

    Directory of Open Access Journals (Sweden)

    W. Pabst

    2004-12-01

    Full Text Available In this fourth paper of a series on the effective elastic properties of alumina-zirconia composite ceramics the influence of porosity on the effective tensile modulus of alumina and zirconia ceramics is discussed. The examples investigated are alumina and zirconia ceramics prepared from submicron powders by starch consolidation casting using two different types of starch, potato starch (median size D50 =47.2 µm and corn starch (median size D50 =13.7 µm. The dependence of effective tensile moduli E, on the porosity f, measured for porosities in the ranges of approx. 19-55 vol.% and 10-42 vol.% for alumina and zirconia, respectively, using a resonant frequency technique, was evaluated by fitting with various model relations, including newly developed ones. A detailed comparison of the fitting results suggests the superiority of the new relation E/E0 = (1 - f·(1 - f/fC, developed by the authors (with the tensile modulus of the dense ceramic material E0 and the critical porosity fC, over most other existing fit models. Only for special purposes and well-behaved data sets the recently proposed exponential relation E/E0 = exp [-Bf/(1 - f] and the well-known Phani-Niyogi relation E/E0 = (1 - f/fCN might be preferable.

  18. Biocompatibility and inflammatory response in vitro and in vivo to gelatin-based biomaterials with tailorable elastic properties.

    Science.gov (United States)

    Ullm, Sandra; Krüger, Anne; Tondera, Christoph; Gebauer, Tim P; Neffe, Axel T; Lendlein, Andreas; Jung, Friedrich; Pietzsch, Jens

    2014-12-01

    Hydrogels prepared from gelatin and lysine diisocyanate ethyl ester provide tailorable elastic properties and degradation behavior. Their interaction with human aortic endothelial cells (HAEC) as well as human macrophages (Mɸ) and granulocytes (Gɸ) were explored. The experiments revealed a good biocompatibility, appropriate cell adhesion, and cell infiltration. Direct contact to hydrogels, but not contact to hydrolytic or enzymatic hydrogel degradation products, resulted in enhanced cyclooxygenase-2 (COX-2) expression in all cell types, indicating a weak inflammatory activation in vitro. Only Mɸ altered their cytokine secretion profile after direct hydrogel contact, indicating a comparably pronounced inflammatory activation. On the other hand, in HAEC the expression of tight junction proteins, as well as cytokine and matrix metalloproteinase secretion were not influenced by the hydrogels, suggesting a maintained endothelial cell function. This was in line with the finding that in HAEC increased thrombomodulin synthesis but no thrombomodulin membrane shedding occurred. First in vivo data obtained after subcutaneous implantation of the materials in immunocompetent mice revealed good integration of implants in the surrounding tissue, no progredient fibrous capsule formation, and no inflammatory tissue reaction in vivo. Overall, the study demonstrates the potential of gelatin-based hydrogels for temporal replacement and functional regeneration of damaged soft tissue. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Biomechanical Consequences of the Elastic Properties of Dental Implant Alloys on the Supporting Bone: Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Esteban Pérez-Pevida

    2016-01-01

    Full Text Available The objective of the present study is to evaluate how the elastic properties of the fabrication material of dental implants influence peri-implant bone load transfer in terms of the magnitude and distribution of stress and deformation. A three-dimensional (3D finite element analysis was performed; the model used was a section of mandibular bone with a single implant containing a cemented ceramic-metal crown on a titanium abutment. The following three alloys were compared: rigid (Y-TZP, conventional (Ti-6Al-4V, and hyperelastic (Ti-Nb-Zr. A 150-N static load was tested on the central fossa at 6° relative to the axial axis of the implant. The results showed no differences in the distribution of stress and deformation of the bone for any of the three types of alloys studied, mainly being concentrated at the peri-implant cortical layer. However, there were differences found in the magnitude of the stress transferred to the supporting bone, with the most rigid alloy (Y-TZP transferring the least stress and deformation to cortical bone. We conclude that there is an effect of the fabrication material of dental implants on the magnitude of the stress and deformation transferred to peri-implant bone.

  20. An elastically compressible phantom material with mechanical and x-ray attenuation properties equivalent to breast tissue

    Science.gov (United States)

    Price, B. D.; Gibson, A. P.; Tan, L. T.; Royle, G. J.

    2010-02-01

    We have developed a novel phantom material: a solution of polyvinyl alcohol (PVAL) in ethanol and water, freeze-thawed to produce a solid yet elastically compressible gel. The x-ray attenuation and mechanical properties of these gels are compared with published measurements of breast tissue. Gels with PVAL concentrations from 5 to 20% w/v were produced. The linear x-ray attenuation coefficients of these gels range from 0.76 to 0.86 cm-1 at 17.5 keV, increasing with PVAL concentration. These values are very similar to the published values of breast tissue at this energy, 0.8-0.9 cm-1. Under compression cancerous breast tissue is approximately ten times stiffer than healthy breast tissue. The Young's moduli of the gels increase with PVAL concentration. Varying the PVAL concentration from 7.5 to 20% w/v produces gels with Young's moduli from 20 to 220 kPa at 15% strain. These values are characteristic of normal and cancerous breast tissue, respectively.

  1. Elastic and electrical properties and permeability of serpentinites from Atlantis Massif, Mid-Atlantic Ridge

    Science.gov (United States)

    Falcon-Suarez, Ismael; Bayrakci, Gaye; Minshull, Tim A.; North, Laurence J.; Best, Angus I.; Rouméjon, Stéphane

    2017-11-01

    Serpentinized peridotites co-exist with mafic rocks in a variety of marine environments including subduction zones, continental rifts and mid-ocean ridges. Remote geophysical methods are crucial to distinguish between them and improve the understanding of the tectonic, magmatic and metamorphic history of the oceanic crust. But, serpentinite peridotites exhibit a wide range of physical properties that complicate such a distinction. We analysed the ultrasonic P- and S-wave velocities (Vp, Vs) and their respective attenuation (Qp-1, Qs-1), electrical resistivity and permeability of four serpentinized peridotite samples from the southern wall of the Atlantis Massif, Mid-Atlantic Ridge, collected during International Ocean Discovery Program Expedition 357. The measurements were taken over a range of loading-unloading stress paths (5-45 MPa), using ˜1.7 cm length, 5 cm diameter samples horizontally extracted from the original cores drilled on the seafloor. The measured parameters showed variable degrees of stress dependence, but followed similar trends. Vp, Vs, resistivity and permeability show good inter-correlations, while relationships that included Qp-1 and Qs-1 are less clear. Resistivity showed high contrast between highly serpentinized ultramafic matrix (>50 Ω m) and mechanically/geochemically altered (magmatic/hydrothermal-driven alteration) domains (seismic techniques and controlled source electromagnetic surveys for understanding tectonomagmatic processes and fluid pathways in hydrothermal systems.

  2. Microstructure, elastic, and inelastic properties of biomorphic carbons carbonized using a Fe-containing catalyst

    Science.gov (United States)

    Orlova, T. S.; Kardashev, B. K.; Smirnov, B. I.; Gutierrez-Pardo, A.; Ramirez-Rico, J.

    2016-12-01

    The microstructure and amplitude dependences of the Young's modulus E and internal friction (logarithmic decrement δ), and microplastic properties of biocarbon matrices BE-C(Fe) obtained by beech tree carbonization at temperatures T carb = 850-1600°C in the presence of an iron-containing catalyst are studied. By X-ray diffraction analysis and transmission electron microscopy, it is shown that the use of Fe-catalyst during carbonization with T carb ≥ 1000°C leads to the appearance of a bulk graphite phase in the form of nanoscale bulk graphite inclusions in a quasi-amorphous matrix, whose volume fraction and size increase with T carb. The correlation of the obtained dependences E( T carb) and δ( T carb) with microstructure evolution with increasing T carb is revealed. It is found that E is mainly defined by a crystalline phase fraction in the amorphous matrix, i.e., a nanocrystalline phase at T carb 1300°C. Maximum values E = 10-12 GPa are achieved for samples with T carb ≈ 1150 and 1600°C. It is shown that the microplasticity manifest itself only in biocarbons with T carb ≥ 1300°C (upon reaching a significant volume of the graphite phase); in this case, the conditional microyield stress decreases with increasing total volume of introduced mesoporosity (free surface area).

  3. Stillinger–Weber potential for elastic and fracture properties in graphene and carbon nanotubes

    Science.gov (United States)

    Hossain, M. Z.; Hao, T.; Silverman, B.

    2018-02-01

    This paper presents a new framework for determining the Stillinger–Weber (SW) potential parameters for modeling fracture in graphene and carbon nanotubes. In addition to fitting the equilibrium material properties, the approach allows fitting the potential to the forcing behavior as well as the mechanical strength of the solid, without requiring ad hoc modification of the nearest-neighbor interactions for avoiding artificial stiffening of the lattice at larger deformation. Consistent with the first-principles results, the potential shows the Young’s modulus of graphene to be isotropic under symmetry-preserving and symmetry-breaking deformation conditions. It also shows the Young’s modulus of carbon nanotubes to be diameter-dependent under symmetry-breaking loading conditions. The potential addresses the key deficiency of existing empirical potentials in reproducing experimentally observed glass-like brittle fracture in graphene and carbon nanotubes. In simulating the entire deformation process leading to fracture, the SW-potential costs several factors less computational time compared to the state-of-the-art interatomic potentials that enables exploration of the fracture processes in large atomistic systems which are inaccessible otherwise.

  4. Monitoring ice thickness and elastic properties from the measurement of leaky guided waves: A laboratory experiment.

    Science.gov (United States)

    Moreau, Ludovic; Lachaud, Cédric; Théry, Romain; Predoi, Mihai V; Marsan, David; Larose, Eric; Weiss, Jérôme; Montagnat, Maurine

    2017-11-01

    The decline of Arctic sea ice extent is one of the most spectacular signatures of global warming, and studies converge to show that this decline has been accelerating over the last four decades, with a rate that is not reproduced by climate models. To improve these models, relying on comprehensive and accurate field data is essential. While sea ice extent and concentration are accurately monitored from microwave imagery, an accurate measure of its thickness is still lacking. Moreover, measuring observables related to the mechanical behavior of the ice (such as Young's modulus, Poisson's ratio, etc.) could provide better insights in the understanding of sea ice decline, by completing current knowledge so far acquired mostly from radar and sonar data. This paper aims at demonstrating on the laboratory scale that these can all be estimated simultaneously by measuring seismic waves guided in the ice layer. The experiment consisted of leaving a water tank in a cold room in order to grow an ice layer at its surface. While its thickness was increasing, ultrasonic guided waves were generated with a piezoelectric source, and measurements were subsequently inverted to infer the thickness and mechanical properties of the ice with very good accuracy.

  5. Liquid crystal elastomer foams with elastic properties specifically engineered as biodegradable brain tissue scaffolds.

    Science.gov (United States)

    Prévôt, M E; Andro, H; Alexander, S L M; Ustunel, S; Zhu, C; Nikolov, Z; Rafferty, S T; Brannum, M T; Kinsel, B; Korley, L T J; Freeman, E J; McDonough, J A; Clements, R J; Hegmann, E

    2017-12-13

    Tissue regeneration requires 3-dimensional (3D) smart materials as scaffolds to promote transport of nutrients. To mimic mechanical properties of extracellular matrices, biocompatible polymers have been widely studied and a diverse range of 3D scaffolds have been produced. We propose the use of responsive polymeric materials to create dynamic substrates for cell culture, which goes beyond designing only a physical static 3D scaffold. Here, we demonstrated that lactone- and lactide-based star block-copolymers (SBCs), where a liquid crystal (LC) moiety has been attached as a side-group, can be crosslinked to obtain Liquid Crystal Elastomers (LCEs) with a porous architecture using a salt-leaching method to promote cell infiltration. The obtained SmA LCE-based fully interconnected-porous foams exhibit a Young modulus of 0.23 ± 0.07 MPa and a biodegradability rate of around 20% after 15 weeks both of which are optimized to mimic native environments. We present cell culture results showing growth and proliferation of neurons on the scaffold after four weeks. This research provides a new platform to analyse LCE scaffold-cell interactions where the presence of liquid crystal moieties promotes cell alignment paving the way for a stimulated brain-like tissue.

  6. A Nanomechanical Approach on the Measurement of the Elastic Properties of Epoxy Reinforced Carbon Nanotube Nanocomposites

    Directory of Open Access Journals (Sweden)

    G. Mansour

    2013-09-01

    Full Text Available The mechanical behavior of nanocomposite materials with multiwallcarbon nanotube ( MWCNT reinforcements is investigated in the present paper. Epoxy nanocomposites with different weight percentages of carbon nanotubes have been characterized following tensile tests and nanoindentations. The objective of this work was to investigate the efficiency of the reinforcement provided by nanotubes and to examine the agreement between the mechanical properties of the epoxynanocomposites obtained via a macroscale and nanoscale experimentalmethods. Higher increase in modulus was accomplished at weight fraction of nanotube reinforcement of 1 %. The modulus as measured by the tensile tests differed an average of 18% with the results obtained from the nanoindentations, however by utilizing a proper calibration method the resulting data were corrected to only a 3% difference. The modulus results obtained from the experiments were compared with the Halpin - Tsai model and with the Thostenson - Chou model accounting for the outer layer interactions of the nanotube with the hosting matrix. A relatively good agreement was found between the models and the experiments.

  7. Phonon Dispersion and Elastic Properties of Two-Dimensional Soft Particle Colloidal Crystals and Glasses

    Science.gov (United States)

    Still, Tim; Chen, Ke; Yunker, Peter J.; Goodrich, Carl P.; Schoenholz, Samuel; Liu, Andrea J.; Yodh, A. G.

    2013-03-01

    We investigate phonon dispersion relations and associated mechanical properties of two-dimensional colloidal glasses and crystals composed of soft, thermoresponsive microgel particles whose temperature-sensitive size facilitates in-situ variation of particle packing fraction. The phonon modes were measured using particle tracking and displacement covariance matrix techniques. Measurements of the hexagonal crystal served to check our methodology and, as expected, the observed phonon dispersion was largely in agreement with theoretical expectations. Measurements of phonon dispersion in the glassy colloids, as a function of packing fraction above the jamming transition, permitted study of the scaling of bulk and shear moduli as a function of packing fraction. We performed numerical simulations and were able to recover the experimental findings. Moreover, the obtained shear moduli are in good agreement with rheological measurements. We gratefully acknowledge financial support from the NSF through DMR12-05463, the PENN MRSEC DMR11-20901, and NASA NNX08AO0G. T. S. acknowledges financial support from DAAD.

  8. Elastic Properties and the Band Gap of AlNxP1-x Semiconductor Alloy: A Comparative Study of Various Ab Initio Approaches

    Directory of Open Access Journals (Sweden)

    M. P. Polak

    2016-01-01

    Full Text Available Structural and elastic properties of AlNxP1-x, a novel semiconductor alloy, are studied from the first principles in both zinc-blende and wurtzite structures. Performances of the finite difference (FD method and the density functional perturbation theory (DFPT are tested and compared. Both of these methods are applied to two different approaches of alloy simulation, a supercell of 16 and 32 atoms (for zinc-blende and wurtzite structures, resp. and the alchemical mixing (AM method, where the pseudopotentials are mixed in an appropriate way to form an alloy. All elastic properties, including the elastic tensors, elastic moduli, Poisson’s ratio, B/G, and relaxation coefficient, as well as lattice parameters are calculated using all said methods. Conclusions about the use of the approaches investigated in this paper and about their performance are drawn. In addition, in both crystal structures, the band gap is studied in the whole composition range using the MBJLDA functional. The band gap bowings are unusually high, which confirms earlier reports.

  9. Elastic properties of ascending aorta in women with previous pregnancy complicated by early- or late-onset pre-eclampsia.

    Science.gov (United States)

    Orabona, R; Sciatti, E; Vizzardi, E; Bonadei, I; Valcamonico, A; Metra, M; Frusca, T

    2016-03-01

    To evaluate the elastic properties of the ascending aorta in women with a previous pregnancy complicated by early-onset (EO) or late-onset (LO) pre-eclampsia (PE) and the correlation with gestational age (GA), systolic/diastolic blood pressure (SBP/DBP) and mean uterine artery pulsatility index (UtA-PI) at diagnosis of the disease as well as with birth weight of the neonate. Thirty women who had a previous pregnancy complicated by EO-PE, 30 with a previous pregnancy complicated by LO-PE and 30 normal controls were selected retrospectively from our electronic database and then recalled for assessment from 6 months to 4 years after delivery. Data regarding GA, SBP/DBP and mean UtA-PI at the diagnosis of PE were obtained from medical records. At our assessment, aortic M-mode and tissue Doppler imaging (TDI) parameters were measured. Aortic diameters were assessed at end-diastole at four levels: Valsalva sinuses, sinotubular junction, tubular tract and aortic arch. Aortic compliance, distensibility, stiffness index (SI), Peterson's elastic modulus (EM), pulse-wave velocity and M-mode strain were calculated using standard formulae. Aortic expansion velocity, early and late diastolic retraction velocities and peak systolic tissue strain (TDI-ϵ) were determined. Aortic diameters at the four levels were significantly greater in both EO-PE and LO-PE groups than in controls. Aortic compliance and distensibility and TDI-ϵ were lower in EO-PE than in LO-PE (P  = 0.001, P  = 0.002 and P  = 0.011, respectively) and controls (P  = 0.037, P  = 0.044 and P  = 0.013, respectively). SI and EM were higher in EO-PE than in LO-PE (P  = 0.001 and P  pregnancy complicated by EO-PE, but not in those with LO-PE. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

  10. Poro-elastic Properties of Whillan's Ice Stream Till: Implications for Basal Stick-Slip

    Science.gov (United States)

    Leeman, J.; Valdez, R. D.; Alley, R. B.; Anandakrishnan, S.; Saffer, D. M.

    2016-12-01

    Whillans ice stream, West Antarctica, flows rapidly from the West Antarctic ice sheet into the Ross Ice Shelf. Regions of highly compacted till, termed sticky-spots, pin the ice in place. Upstream ice flow increases driving stress, until minor changes in buttressing stresses from tides affecting the ice shelf cause the main sticky-spot to fail, triggering diurnal or semidiurnal stick-slip events. The mechanical and hydrological properties of the till partially control the basal conditions, generation and persistence of the sticky spots, and thus the dynamics of the rupture and healing processes. Here we present laboratory tests on core samples of the till beneath Whillan's Ice Stream collected in the 1989-1993 field seasons. Two types of tests were performed on till cores: stepped loading and cyclic loading. In the stepped loading test, the effective stress was increased from 0.1 to 10 MPa in a series of steps, and the permeability measured at each step. Cyclic loading tests consisted of a series of effective stress oscillations with 24 h period lasting 5-10 d each, increasing in amplitude from 20-150 kPa. The permeability was measured after each set of oscillations to investigate the role of cyclic loading in driving enhanced compaction. Compressional wave velocity (Vp) was also measured during both test sequences. We observe sample initial porosities of 30% and permeabilities of 3x10-17 m2. During stepped loading tests, porosity is reduced to 20% and permeability to 8x10-18 m2. Vp ranged from 2.2-2.95 km s-1 and was well fit by an effective medium model. Application of this model to Vp obtained by field seismic surveys is consistent with low ( 50 kPa) effective vertical stresses in the uppermost till. Cyclic loading sequences reduced porosity by 4% and permeability by an order of magnitude. A transient numerical model based on our data shows that over the tidal timescale, a layer of stiffened till 10 cm thick should develop. We suggest that this provides one

  11. Effect of ripples on the finite temperature elastic properties of hexagonal boron nitride using strain-fluctuation method

    Science.gov (United States)

    Thomas, Siby; Ajith, K. M.; Valsakumar, M. C.

    2017-11-01

    This work intents to put forth the results of a classical molecular dynamics study to investigate the temperature dependent elastic constants of monolayer hexagonal boron nitride (h-BN) between 100 and 1000 K for the first time using strain fluctuation method. The temperature dependence of out-of-plane fluctuations (ripples) is quantified and is explained using continuum theory of membranes. At low temperatures, negative in-plane thermal expansion is observed and at high temperatures, a transition to positive thermal expansion has been observed due to the presence of thermally excited ripples. The decrease of Young's modulus, bulk modulus, shear modulus and Poisson's ratio with increase in temperature has been analyzed. The thermal rippling in h-BN leads to strong anharmonic behaviour that causes large deviation from the isotropic elasticity. A detailed study shows that the strong thermal rippling in large systems is also responsible for the softening of elastic constants in h-BN. From the determined values of elastic constants and elastic moduli, it has been elucidated that 2D h-BN sheets meet the Born's mechanical stability criterion in the investigated temperature range. The variation of longitudinal and shear velocities with temperature is also calculated from the computed values of elastic constants and elastic moduli.

  12. Melt processing and property testing of a model system of plastics contained in waste from electrical and electronic equipment.

    Science.gov (United States)

    Triantou, Marianna I; Tarantili, Petroula A; Andreopoulos, Andreas G

    2015-05-01

    In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile-butadiene-styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile-butadiene-styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile-butadiene-styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile-butadiene-styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2 phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile-butadiene-styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile-butadiene-styrene terpolymer/polycarbonate and acrylonitrile-butadiene-styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile-butadiene-styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment. © The Author(s) 2015.

  13. First-principles calculations of the structural, elastic and thermodynamic properties of mackinawite (FeS) and pyrite (FeS2)

    Science.gov (United States)

    Wen, Xiangli; Liang, Yuxuan; Bai, Pengpeng; Luo, Bingwei; Fang, Teng; Yue, Luo; An, Teng; Song, Weiyu; Zheng, Shuqi

    2017-11-01

    The thermodynamic properties of Fe-S compounds with different crystal structure are very different. In this study, the structural, elastic and thermodynamic properties of mackinawite (FeS) and pyrite (FeS2) were investigated by first-principles calculations. Examination of the electronic density of states shows that mackinawite (FeS) is metallic and that pyrite (FeS2) is a semiconductor with a band gap of Eg = 1.02 eV. Using the stress-strain method, the elastic properties including the bulk modulus and shear modulus were derived from the elastic Cij data. Density functional perturbation theory (DFPT) calculations within the quasi-harmonic approximation (QHA) were used to calculate the thermodynamic properties, and the two Fe-S compounds are found to be dynamically stable. The isothermal bulk modulus, thermal expansion coefficient, heat capacities, Gibbs free energy and entropy of the Fe-S compounds are obtained by first-principles phonon calculations. Furthermore, the temperature of the mackinawite (FeS) ⟶ pyrite (FeS2) phase transition at 0 GPa was predicted. Based on the calculation results, the model for prediction of Fe-S compounds in the Fe-H2S-H2O system was improved.

  14. Macrophage adhesion on fibronectin evokes an increase in the elastic property of the cell membrane and cytoskeleton: an atomic force microscopy study.

    Science.gov (United States)

    Souza, Samuel T; Agra, Laís C; Santos, Cássio E A; Barreto, Emiliano; Hickmann, Jandir M; Fonseca, Eduardo J S

    2014-12-01

    Interactions between cells and microenvironments are essential to cellular functions such as survival, exocytosis and differentiation. Cell adhesion to the extracellular matrix (ECM) evokes a variety of biophysical changes in cellular organization, including modification of the cytoskeleton and plasma membrane. In fact, the cytoskeleton and plasma membrane are structures that mediate adherent contacts with the ECM; therefore, they are closely correlated. Considering that the mechanical properties of the cell could be affected by cell adhesion-induced changes in the cytoskeleton, the purpose of this study was to investigate the influence of the ECM on the elastic properties of fixed macrophage cells using atomic force microscopy. The results showed that there was an increase (~50%) in the Young's modulus of macrophages adhered to an ECM-coated substrate as compared with an uncoated glass substrate. In addition, cytochalasin D-treated cells had a 1.8-fold reduction of the Young's modulus of the cells, indicating the contribution of the actin cytoskeleton to the elastic properties of the cell. Our findings show that cell adhesion influences the mechanical properties of the plasma membrane, providing new information toward understanding the influence of the ECM on elastic alterations of macrophage cell membranes.

  15. Proposal of concentration limits for determining the hazard property HP 14 for waste using ecotoxicological tests.

    Science.gov (United States)

    Hennebert, Pierre

    2017-12-05

    Different ecotoxicological test batteries and concentration limits have been proposed to assess the hazard property (HP) HP 14 'Ecotoxic' for waste in the European Union and its member states. In test batteries, if the concentration of waste in the culture/dilution medium producing 50% of inhibitory biological effect in one or more test(s) is below the concentration limit of the test, the waste is classified as hazardous. A summarized review of the test batteries proposed since 1998 is presented. The last proposed test battery uses seven aquatic and terrestrial species with standardized methods, but with options and uniform concentration limits of 10% of waste eluate or solid waste in the culture/dilution medium. No attempt was made to match this hazard assessment with the classification made in the European List of Waste (LoW). The aim of this paper is to propose for the same test battery (reduced to 6 tests without options) concentration limits that match with the European List of Waste. This list was taken as reference (despite the fact that waste can be hazardous for other properties than the most frequent HP 14, and its partly political nature for some opinions). The concentration limits (CLs) for tests are the concentrations producing the highest ecotoxicological effects for each test observed in a non-hazardous waste set. Data from Germany, France and Belgium (from in total 5 different sources from 2009 to 2016) with the above-mentioned test battery (without options) were gathered for 81 samples, being the largest set ever published. In total, ten non-hazardous (NH) waste samples (as defined by the LoW and for most of them checked by chemical composition) were used to establish CLs. These CLs were then applied to 13 hazardous (H) waste by the LoW, and all were classified as hazardous. The matching of the resulting classification with the LoW is convincing. For the 58 'mirror entries' in the LoW (hazardous or not depending of the presence of hazardous

  16. Tillage and kitchen wastes effect on Peri-Urban soil properties and ...

    African Journals Online (AJOL)

    Tillage and kitchen wastes effect on Peri-Urban soil properties and vegetable cowpea (). PC Nnabude, CO Obi, E Onuoha. Abstract. No Abstract. Nigerian Journal of Soil Science Vol. 16 (1) 2006: pp. 140-144. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  17. Investigation of combined effect of mixture variables on mechanical properties of cement treated demolition waste

    NARCIS (Netherlands)

    Xuan, D.; Houben, L.J.M.; Molenaar, A.A.A.; Shui, Z.

    2012-01-01

    One of high efficient ways to reuse the recycled construction and demolition waste (CDW) is to consider it as a road base material. The recycled CDW however is mainly a mix of recycled masonry and concrete with a wide variation in composition. This results that the mechanical properties of cement

  18. Structural, elastic and electronic properties of C14-type Al{sub 2}M (M=Mg, Ca, Sr and Ba) Laves phases

    Energy Technology Data Exchange (ETDEWEB)

    Lishi, Ma; Yonghua, Duan, E-mail: duanyh@kmust.edu.cn; Runyue, Li

    2017-02-15

    The structural and mechanical properties, Debye temperatures and anisotropic sound velocities of the Laves phases Al{sub 2}M (M=Mg, Ca, Sr and Ba) with C14-type structure were investigated using the first-principles corresponding calculations. The corresponding calculated structural parameters and formation enthalpies are in good agreement with the available theoretical values, and Al{sub 2}Ca has the best phase stability. The mechanical properties, including elastic constants, bulk modulus B, shear modulus G, Young’s modulus E, and Poisson ratio ν, were deduced within the Voigt-Reuss-Hill approximation. The brittleness and ductility were estimated by the values of Poisson ratio, B/G and Cauchy pressure. Moreover, the elastic anisotropy was investigated by calculating and discussing several anisotropy indexes. Finally, the electronic structures were used to illustrate the bonding characteristics of C14-Al{sub 2}M (M=Mg, Ca, Sr and Ba) phases.

  19. Ab-initio study of structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys

    Directory of Open Access Journals (Sweden)

    Chelli S.

    2015-12-01

    Full Text Available The structural, elastic, electronic and thermodynamic properties of BaxSr1−xS ternary alloys have been investigated using the full-potential (linearized augmented plane wave method. The ground state properties, such as lattice constant, bulk modulus and elastic constants, are in good agreement with numerous experimental and theoretical data. The dependence of the lattice parameters, bulk modulus and band gap on the composition x was analyzed. Deviation of the lattice constant from Vegard’s law and the bulk modulus from linear concentration dependence (LCD was observed. The microscopic origins of the gap bowing were explained by using the approach of Zunger et al. The thermodynamic stability of BaxSr1−xS alloy was investigated by calculating the excess enthalpy of mixing, ΔHm and the calculated phase diagram showed a broad miscibility gap with a critical temperature.

  20. First-principles calculations of elastic and thermo-physical properties of Al, Mg and rare earth lanthanide elements

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang Yifang, E-mail: ouyangyf@gxu.edu.c [Department of Physics, Guangxi University, Nanning 530004 (China); Tao Xiaoma; Zeng Fanjiang; Chen Hongmei [Department of Physics, Guangxi University, Nanning 530004 (China); Du Yong [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Feng Yuanping [Department of Physics, National University of Singapore, 119260 Singapore (Singapore); He Yuehui [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2009-08-01

    The elastic constants of the Al, Mg and rare earth (RE) lanthanide elements have been calculated at T=0 K by using the projector augmented-wave (PAW) method within the generalized gradient approximation (GGA). The bulk moduli, shear moduli, Young's moduli and Poisson's ratio of poly-crystalline solid are estimated from the calculated elastic constants of single crystal. Based on the quasi-harmonic Debye model, the Debye temperature, heat capacity, Grueneisen parameter and linear thermal expansion coefficient are also estimated. The present calculated results are in reasonable agreement with the available experimental data and other theoretical results. The present calculation of elastic constants for Ce also indicates that the PAW potential (named 'Ce{sub 3}'), for which one f electron is kept frozen in the core and hence fix the valency of Ce to three (Ce{sub 3}) does not yield good results for the elastic constants.

  1. Effects of Waste Plastic on the Physical and Rheological Properties of Bitumen

    Science.gov (United States)

    Ezree Abdullah, Mohd; Asyiqin Ahmad, Nurul; Putra Jaya, Ramadhansyah; Hassan, Norhidayah Abdul; Yaacob, Haryati; Rosli Hainin, Mohd

    2017-05-01

    Plastic disposal is one of the major problems for developing countries like Malaysia, at the same time Malaysia needs a large network of roads for its smooth economic and social development. The limited source of bitumen needs a deep thinking to ensure fast road construction. Therefore, the use of plastic waste in road construction not only can help to protect environment but also able to help the road construction industry. The aims of this research are to study the effects of waste plastic on rheological properties of bitumen. Modified bitumen was prepared by using blending techniques. Bitumen was heated and plastic waste was slowly added. Rheological properties of bitumen were performance by penetration, softening point, viscosity and direct shear rheometer test. The results showed that when content of plastic waste increase, the penetration value, softening point and viscosity of bitumen also increase. Generally, plastic waste improves the performance of bitumen when it was added into bitumen. It can be said that the usage helps to improve the performance of the road pavement which also reduces the rutting effect.

  2. Ab initio study of the structural and elastic properties of spinels MgX2O4(X = Al, Ga, In) under pressure

    Science.gov (United States)

    Bouhemadou, A.; Khenata, R.; Zerarga, F.

    2007-03-01

    We perform ab initio calculations using a pseudo-potential plane-wave method based on density functional theory, within the local density approximation and generalized gradient approximation, in order to determine and predict the pressure dependence of structural and elastic properties of spinel compounds: MgAl2O4, MgGa2O4 and MgIn2O4. The results are in agreement with the available experimental data and other theoretical calculations.

  3. An experimental study of elastic properties of dragonfly-like flapping wings for use in biomimetic micro air vehicles (BMAVs

    Directory of Open Access Journals (Sweden)

    Praveena Nair Sivasankaran

    2017-04-01

    Full Text Available This article studies the elastic properties of several biomimetic micro air vehicle (BMAV wings that are based on a dragonfly wing. BMAVs are a new class of unmanned micro-sized air vehicles that mimic the flapping wing motion of flying biological organisms (e.g., insects, birds, and bats. Three structurally identical wings were fabricated using different materials: acrylonitrile butadiene styrene (ABS, polylactic acid (PLA, and acrylic. Simplified wing frame structures were fabricated from these materials and then a nanocomposite film was adhered to them which mimics the membrane of an actual dragonfly. These wings were then attached to an electromagnetic actuator and passively flapped at frequencies of 10–250 Hz. A three-dimensional high frame rate imaging system was used to capture the flapping motions of these wings at a resolution of 320 pixels × 240 pixels and 35000 frames per second. The maximum bending angle, maximum wing tip deflection, maximum wing tip twist angle, and wing tip twist speed of each wing were measured and compared to each other and the actual dragonfly wing. The results show that the ABS wing has considerable flexibility in the chordwise direction, whereas the PLA and acrylic wings show better conformity to an actual dragonfly wing in the spanwise direction. Past studies have shown that the aerodynamic performance of a BMAV flapping wing is enhanced if its chordwise flexibility is increased and its spanwise flexibility is reduced. Therefore, the ABS wing (fabricated using a 3D printer shows the most promising results for future applications.

  4. Studying the Effect of ZnO on Physical and Elastic Properties of (ZnOx(P2O51−x Glasses Using Nondestructive Ultrasonic Method

    Directory of Open Access Journals (Sweden)

    Khamirul Amin Matori

    2015-01-01

    Full Text Available Binary zinc phosphate glass system with composition of (ZnOx(P2O51−x, (x = 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 mol% was successfully prepared using a conventional melt-quenching method. Composition dependence of physical properties and elastic properties in the (ZnOx(P2O51−x were discussed in association with the effects of adding zinc oxide (ZnO as a modifier. The addition of ZnO modifier was expected to produce substantial changes on physical properties of the phosphate glasses. An increase in density values of the phosphate glasses was observed. Elastic moduli were studied by measuring ultrasonic longitudinal and shear velocities (Vl and Vt of the glasses at room. Longitudinal modulus, shear modulus, bulk modulus, Young’s modulus, Poisson’s ratio, and Debye temperature (θD were derived from both data of velocities and respective density of all of the samples. Findings from present work showed dependence of density and elastic moduli of each ZnO-P2O5 series on glass composition.

  5. First principles calculations on elasticity, electronic structure and bonding properties of antiperovskites ANTi{sub 3} (A = Al, In and Tl)

    Energy Technology Data Exchange (ETDEWEB)

    Cherrad, Djellal, E-mail: cherradphisic@yahoo.fr [Laboratory for Developing New Materials and their Characterizations, University of Setif (Algeria); Selmani, L. [University Center of BBA (Algeria); Maouche, D. [Laboratory for Developing New Materials and their Characterizations, University of Setif (Algeria); Maamache, M. [Department of Physics, Faculty of Sciences, University of Setif (Algeria)

    2011-03-24

    Research highlights: > In this study the B/G values of ANTi{sub 3} show that these materials behave as ductile. > Band structures show that are conductors and exhibit magnetism. > Therefore lead to lower T{sub c} or no superconducting behavior in our compounds. > The chemical bonding in ANTi{sub 3} compounds may be covalent-ionic. > Elastic properties of our compounds show a correlation with the bonding properties. - Abstract: We use an ab initio pseudopotential plane wave (PP-PW) method within the generalized gradient approximation (GGA) and the local density approximation (LDA) to study the structural, elastic and electronic properties of the unexplored antiperovskite ANTi{sub 3} compounds. The elastic constants C{sub 11}, C{sub 12}, C{sub 44} and their pressure dependence are calculated. We derived the bulk, shear and Young's moduli for ideal monocrystalline and for polycrystalline ANTi{sub 3} aggregates which we have classified as ductile in nature. Band structures reveal that these compounds are conductors. The covalent ionic bands nature is due to the strong hybridization between Ti 3d and N 2p states. The Ti 3d states play dominant roles near the Fermi levels for all these compounds. The energy difference between spin polarized calculations and the nonspin polarized calculations indicate that ANTi{sub 3} compounds exhibit magnetism at their equilibrium lattice constants.

  6. Thermal Expansion, Elastic and Magnetic Properties of FeCoNiCu-Based High-Entropy Alloys Using First-Principle Theory

    Science.gov (United States)

    Huang, Shuo; Vida, Ádám; Heczel, Anita; Holmström, Erik; Vitos, Levente

    2017-11-01

    The effects of V, Cr, and Mn on the magnetic, elastic, and thermal properties of FeCoNiCu high-entropy alloy are studied by using the exact muffin-tin orbitals method in combination with the coherent potential approximation. The calculated lattice parameters and Curie temperatures in the face-centered-cubic structure are in line with the available experimental and theoretical data. A significant change in the magnetic behavior is revealed when adding equimolar V, Cr, and Mn to the host composition. The three independent single-crystal elastic constants are computed using a finite strain technique, and the polycrystalline elasticity parameters including shear modulus, Young's modulus, Pugh ratio, Poisson's ratio, and elastic anisotropy are derived and discussed. The effects of temperature on the structural parameters are determined by making use of the Debye-Grüneisen model. It is found that FeCoNiCuCr possesses a slightly larger thermal expansion coefficient than do the other alloys considered here.

  7. Elastic properties of terbium

    DEFF Research Database (Denmark)

    Spichkin, Y.I.; Bohr, Jakob; Tishin, A.M.

    1996-01-01

    The temperature dependence of the Young modulus along the crystallographic axes b and c (E(b) and E(c)), and the internal friction of a terbium single crystal have been measured. At 4.2 K, E(b) and E(c) are equal to 38 and 84.5 GPa, respectively. The lattice part of the Young modulus and the Debye...... temperature has been calculated. The origin of the Young modulus anomalies arising at the transition to the magnetically ordered state is discussed....

  8. Physical and mechanical properties of composite materials of different compositions based on waste products

    OpenAIRE

    A.E. Burdonov; V.V. Barakhtenko; E.V. Zelinskaya; E.O. Suturina; A.V. Burdonova; A.V. Golovnina

    2012-01-01

    This paper presents a study on the effect of mineral filler on the polymer composite material based on waste products of heat and power engineering - fly ash. This type of waste products has never been used for the production of polymer-mineral composites. Depending on the type of ash, its chemical composition and its quantity in the material, we can adjust the properties of the resulting composites. The use of fly ash as a filler will not only make a product less expensive, but it also will ...

  9. Properties of SYNROC C nuclear-waste form: a state-of-the-art review

    Energy Technology Data Exchange (ETDEWEB)

    Oversby, V.M.

    1982-09-01

    SYNROC C is a titanate ceramic waste form designed to contain the waste generated by the reprocessing of commercial nuclear reactor fuel. The properties of SYNROC C are described with particular emphasis on the distribution of chemical elements in SYNROC, the fabrication of good quality specimens, and the chemical durability of SYNROC. Data obtained from testing of natural mineral analogues of SYNROC minerals are briefly discussed. The information available on radiation effects in SYNROC in relation to structural alteration and changes in chemical durability are summarized. 26 references, 2 figures, 18 tables.

  10. Thermal properties of light-weight concrete with waste polypropylene aggregate

    Science.gov (United States)

    Záleská, Martina; Pokorný, Jaroslav; Pavlíková, Milena; Pavlík, Zbyšek

    2017-07-01

    Thermal properties of a sustainable light-weight concrete incorporating high volume of waste polypropylene as partial substitution of natural aggregate were studied in the paper. Glass fiber reinforced polypropylene (GFPP), a by-product of PP tubes production, partially substituted fine natural silica aggregate in 10, 20, 30, 40, and 50 mass%. In order to quantify the effect of GFPP use on concrete properties, a reference concrete mix without plastic waste was studied as well. For the applied GFPP, bulk density, matrix density, and particle size distribution were measured. Specific attention was paid to thermal transport and storage properties of GFPP that were examined in dependence on compaction time. For the developed light-weight concrete, thermal properties were accessed using transient impulse technique, whereas the measurement was done in dependence on moisture content, from the dry state to fully water saturated state. Additionally, the investigated thermal properties were plotted as function of porosity. The tested light-weight concrete was found to be prospective construction material possessing improved thermal insulation function. Moreover, the reuse of waste plastics in concrete composition was beneficial both from the environmental and financial point of view considering plastics low biodegradability and safe disposal.

  11. Physicochemical properties, nutritional value and techno-functional properties of goldenberry (Physalis peruviana) waste powder concise title: Composition of goldenberry juice waste.

    Science.gov (United States)

    Mokhtar, Sayed M; Swailam, Hesham M; Embaby, Hassan El-Sayed

    2018-05-15

    Goldenberry waste powder, contained 5.87% moisture, 15.89% protein, 13.72% fat, 3.52% ash, 16.74% dietary fiber and 61% carbohydrates. Potassium (560 mg/100 g) was the predominant element followed by sodium (170 mg/100 g) and phosphorus (130 mg/100 g). Amino acid analysis gave high levels of cystine/methionine, histidine and tyrosine/phenylalanine. Goldenberry waste powder had good levels of the techno-functional properties including water absorption index, swelling index, foaming capacity and stability (3.38 g/g, 5.24 ml/g, 4.09 and 72.0%, respectively). Fatty acids profile showed that linoleic acid was the predominant fatty acid followed by oleic, palmitic and stearic acids. Iodine value (109.5 g/100 g of oil), acid value (2.36 mg KOH/g of oil), saponification value (183.8 mg KOH/g of oil), peroxide value (8.2 meq/kg of oil) and refractive index (1.4735) were comparable to those of soybean and sunflower oils. Goldenberry waste oil exhibited absorbance in the UV range at 100-400 nm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Permeation properties of Concrete Added with a Petrochemical Industry Waste

    Directory of Open Access Journals (Sweden)

    Janneth Torres-Agredo

    2017-09-01

    Full Text Available The aim of this study is to evaluate the permeation properties of concrete added with a residue of a petrochemical industry located in Colombia, called catalytic cracking catalyst residue (FCC. Concrete samples with 10, 20 and 30 % of FCC incorporated as cement replacement were evaluated. As reference materials, concrete without addition and concrete added with 20 % of metakaolin (MK were used. MK is a high performance pozzolan of chemical composition similar to the FCC. The properties studied, in addition to the compressive strength, were: water absorption by total immersion, porosity, surface absorption and capillary sorption. The results showed that the concrete added with FCC and MK had similar behavior, and were slightly higher than the control sample. The total absorption and porosity were below 5 % and 10 % respectively for all samples; this means that the incorporation of the addition reduces the permeability of concrete. In this sense, FCC is considered as a good alternative for producing more durable concrete, being the optimum percentage, 10 % cement replacement.

  13. Physical properties of heat-treated rattan waste binderless particleboard

    Science.gov (United States)

    Tajuddin, Maisarah; Ahmad, Zuraida; Halim, Zahurin; Maleque, Md Abd; Ismail, Hanafi; Sarifuddin, Norshahida

    2017-07-01

    The objective of this study is to investigate the effects of heat treatment on the properties of binderless particleboard (BPB) fabricated via hot-pressing process with pressing temperature, pressing time and pressing pressure of 180°C, 5 minutes and 1 MPa, respectively. The fabricated BPB with density in the range of 0.8-0.95g cm-3 was heated in a temperature-controlled laboratory chamber at 80°C, 120°C and 160°C for period of 2 and 8 hours before underwent physical observation, mass loss measurement and thickness swelling test. The samples had remarkable color changes, mainly with samples of treatment temperature of 160˚C, where the color differences were 9.5 and 20.3. This changed the fabricated BPB samples from yellowish brown to dark brown color when treatment conditions increased. Darker color indicates greater mass loss due to severity of chemical component in the powder. Dimensional stability of fabricated BPB was improved with higher treatment temperature as more cellulose cross-linked and hemicellulose degraded that removed the hygroscopicity behavior of powder. These results revealed that heat treatment helped in improving the BPB physical properties, particularly in dimensional stability of boards.

  14. Marshall properties of asphalt concrete using crumb rubber modified of motorcycle tire waste

    Science.gov (United States)

    Siswanto, Henri; Supriyanto, Bambang; Pranoto, Chandra, Pria Rizky; Hakim, Arief Rahman

    2017-09-01

    The aim of this study is to explain the effect of Crumb Rubber Modified (CRM) of motorcycle tire waste on Marshall properties of asphalt mix. Two types of aggregate gradation, asphalt concrete wearing course (ACWC) and asphalt concrete base (ACB), and CRM passing #50 sieve size were used. Seven levels of CRM content were investigated in this study, namely 0%, 0.5%, 1%, 1.5%, 3%, 4.5%, and 6% by weight of aggregate. Marshall test is conducted on Marshall specimens. The specimens are tested in their optimum binder content (OBC). The results indicate that CRM addition of motorcycle tire waste increases the Marshall stability of the both mix, ACWC and ACB. In addition, 1% CRM addition of motorcycle tire waste of the total mix weight is the best mix.

  15. Effect of Using Windows Waste Glass as Fine Aggregate on Some Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Abdelmaseeh Bakos Keryou

    2017-12-01

    Full Text Available The main goal of this study is to investigate the effect of using waste glass (WG on some mechanical properties of concrete at both fresh and hardened stages. In our study, we used local windows waste glass (WG as partial replacement of fine aggregates with 0, 20, 25, and 30% percentages (by weight. The experimental results obtained from testing specimens prepared from concrete mixes with water/cement ratio equal to 0.5, showed that the optimum percentage of fine waste glass to be used within the concrete mix was 20%. At this percentage of replacement the compressive strength obtained at 28-days age was 39 MPa compared with 30.32 MPa for reference concrete mix.

  16. Structural and elastic properties under pressure effect of the cubic antiperovskite compounds ANCa{sub 3} (A = P, As, Sb, and Bi)

    Energy Technology Data Exchange (ETDEWEB)

    Haddadi, K. [Laboratory for Developing New Materials and their Characterization, Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria)], E-mail: haddadi_khelifa@yahoo.fr; Bouhemadou, A.; Louail, L.; Maabed, S.; Maouche, D. [Laboratory for Developing New Materials and their Characterization, Department of Physics, Faculty of Science, University of Setif, 19000 Setif (Algeria)

    2009-04-27

    Using first-principles density functional calculations, the effect of high pressures, up to 40 GPa, on the structural and elastic properties of ANCa{sub 3}, with A = P, As, Sb, and Bi, were studied by means of the pseudo-potential plane-waves method. Calculations were performed within the local density approximation and the generalized gradient approximation for exchange-correlation effects. The lattice constants are in good agreement with the available results. The elastic constants and their pressure dependence are calculated using the static finite strain technique. We derived the bulk and shear moduli, Young's modulus, Poisson's ratio and Lame's constants for ideal polycrystalline ANCa{sub 3} aggregates. By analysing the ratio between the bulk and shear moduli, we conclude that ANCa{sub 3} compounds are brittle in nature. We estimated the Debye temperature of ANCa{sub 3} from the average sound velocity. This is the first quantitative theoretical prediction of the elastic properties of PNCa{sub 3}, AsNCa{sub 3}, SbNCa{sub 3}, and BiNCa{sub 3} compounds, and it still awaits experimental confirmation.

  17. In-situ neutron diffraction of LaCoO3 perovskite under uniaxial compression. II. Elastic properties

    Science.gov (United States)

    Lugovy, Mykola; Aman, Amjad; Chen, Yan; Orlovskaya, Nina; Kuebler, Jakob; Graule, Thomas; Reece, Michael J.; Ma, Dong; Stoica, Alexandru D.; An, Ke

    2014-07-01

    Calculations of elastic constants and development of elastic anisotropy under uniaxial compression in originally isotropic polycrystalline LaCoO3 perovskite are reported. The lattice strains in individual (hkl) planes as well as average lattice strain were determined both for planes oriented perpendicular and parallel to the loading direction using in-situ neutron diffraction. Utilizing average lattice strains as well as lattice strains along the a and c crystallographic directions, an attempt was made to determine Poisson's ratio of LaCoO3, which was then compared with that measured using an impulse excitation technique. The elastic constants were calculated and Young's moduli of LaCoO3 single crystal in different crystallographic directions were estimated.

  18. In-situ neutron diffraction of LaCoO{sub 3} perovskite under uniaxial compression. II. Elastic properties

    Energy Technology Data Exchange (ETDEWEB)

    Lugovy, Mykola [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Institute for Problems of Materials Science, Kiev 03142 (Ukraine); Aman, Amjad; Orlovskaya, Nina, E-mail: Nina.Orlovskaya@ucf.edu [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Chen, Yan [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, Florida 32816 (United States); Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Kuebler, Jakob; Graule, Thomas [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for High Performance Ceramics, Ueberlandstrasse 129, 8600 Duebendorf (Switzerland); Reece, Michael J. [The School of Engineering and Materials Science, Queen Mary, University of London, London E1 4NS (United Kingdom); Ma, Dong; Stoica, Alexandru D.; An, Ke [Chemical and Engineering Materials Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-07-07

    Calculations of elastic constants and development of elastic anisotropy under uniaxial compression in originally isotropic polycrystalline LaCoO{sub 3} perovskite are reported. The lattice strains in individual (hkl) planes as well as average lattice strain were determined both for planes oriented perpendicular and parallel to the loading direction using in-situ neutron diffraction. Utilizing average lattice strains as well as lattice strains along the a and c crystallographic directions, an attempt was made to determine Poisson's ratio of LaCoO{sub 3}, which was then compared with that measured using an impulse excitation technique. The elastic constants were calculated and Young's moduli of LaCoO{sub 3} single crystal in different crystallographic directions were estimated.

  19. Nonlinear elastic properties of superconducting antiperovskites MNNi 3 (M =Zn, Cd, Mg, Al, Ga, and In) from first principles

    KAUST Repository

    Liu, Lili

    2014-05-22

    We present theoretical studies for the third-order elastic constants (TOECs) of superconducting antiperovskites MNNi 3 (M = Zn, Cd, Mg, Al, Ga, and In) using the density functional theory (DFT) and homogeneous deformation method. From the nonlinear least-square fitting, the elastic constants are extracted from a polynomial fit to the calculated strain-energy data. Calculated second-order elastic constants (SOECs) are compared with the previous theoretical calculations, and a very good agreement was found. The nonlinear effects often play an important role when the finite strains are larger than approximately 2.5 %. Besides, we have computed the pressure derivatives of SOECs and provided rough estimations for the Grüneisen constants of long-wavelength acoustic modes by using the calculated TOECs. © 2014 Springer Science+Business Media New York.

  20. Response Surfaces for Fresh and Hardened Properties of Concrete with E-Waste (HIPS

    Directory of Open Access Journals (Sweden)

    K. Senthil Kumar

    2014-01-01

    Full Text Available The fresh and hardened properties of concrete with E-waste plastic, that is, high impact polystyrene (HIPS, as a partial replacement for coarse aggregate were analyzed using response surface methodology (RSM. Face-centred central composite response surface design was used in this study. The statistical models were developed between the factors (HIPS and water cement ratio and their response variables (slump, fresh density, dry density, compressive strength, spilt tensile strength, and flexural strength. The Design-Expert 9.0.3 software package was used to analyze the experimental values. The relationships were established and final mathematical models in terms of coded factors from predicted responses were developed. The effects of factors on properties for all variables were seen visually from the response surface and contour plot. Validation of experiments has shown that the experimental value closely agreed with the predicted value, which validates the calculated response surface models with desirability = 1. The HIPS replacement influenced all the properties of concrete than water cement ratio. Even though all properties show the decline trend, the experimented values and predicted values give a hope that the E-waste plastic (HIPS can be used as coarse aggregate up to certain percentage of replacement in concrete which successively reduces the hazardous solid waste problem and conserves the natural resources from exhaustion.

  1. Tensile properties of chrome tanned leather waste short fibre filled unsaturated polyester composite

    Science.gov (United States)

    Talib, Satariah; Romli, Ahmad Zafir; Saad, Siti Zaleha

    2017-12-01

    Waste leather from industries was commonly disposed via land filling or incineration where the oxidation of Cr III to Cr VI by oxidants (such as peroxides and hypohalide) can easily occur. Cr VI is well known as carcinogenic and mutagenic element where the excessive exposure to this element can be very harmful. As an alternative way, the leather waste from footwear industry was utilised as filler in unsaturated polyester composite (UPC). The leather waste was ground using 0.25 mm mesh size and used without any chemical treatment. The sample was fabricated via castingtechnique and the study was carried out at 1 wt%, 2 wt% and 3 wt% filler loading. The leather waste filled composites showed lower tensile strength and Young's modulus than the unfilled composite. The increasing loading amount of leather waste led to the decreased in tensile strength and Young's modulus. The tensile results was supported by the decreasing pattern of density result which indicates the increasing of void content as the filler loading increased. The results of glass transition temperature are also parallel to the tensile properties where the increasing filler loading had decreased the glass transition temperature. Based on the morphological observation on the fractured tensile sample, much severe filler agglomerations and higher amount of voids was observed at higher filler loading compared to the lower filler loading.

  2. Effect of waste banner as fiber on mechanical properties of concrete

    Science.gov (United States)

    Rahmawati, Anis; Saputro, Ida Nugroho

    2017-06-01

    Banner is broadly used as advertisement media and event backdrop that is usually only used at one moment, resulting to a lot of waste banners. Banner made from nylon fiber is covered by polyvinyl. Nylon is well known as a material with high tensile strength. This research was done as a preliminary investigation on the opportunity of using the waste banner as fiber material of concrete by evaluating its mechanical properties, namely compressive and flexural strength. Research conducted by making cylinder shape specimens of 15 mm in diameter and 300 mm in height for the compressive strength test. While the specimen shape for flexural strength test was a rectangular prism with dimension of 150 mm in height, 150 mm in width, and 600 mm in length. Fiber generated from waste banner was added in concrete mixtures with percentage of 0.00%, 0.20%, 0.40%, 0.60%, 0.80%, and 1.00% by weight of concrete. The concrete strength was tested at 28 days after standard moisture and temperature curing. Experimental results indicated that the addition of 0.20% of waste banner obtained the highest compressive strength that was 21.967 Mpa, while 0.40% of waste banner obtained the highest flexural strength of 4.663 Mpa.

  3. The evaluation of chosen properties of ashes created by thermal utilization of hazardous and communal wastes

    Directory of Open Access Journals (Sweden)

    Damian Krawczykowski

    2005-11-01

    Full Text Available One of methods of the waste neutralization is their thermal transformation in suitable installations or devices in order to achieve the state, which is no longer dangerous for the human health and life or for the environment. In effect of the thermal transformation the “new” wastes are created, which, by law are suppose a to be utilized first. These wastes may be utilized if their properties are suitable. In the paper, the process of thermal utilization of hazardous and municipal wastes is presented, together with the investigation results of the grain composition, surface area, density and of the initial chemical analysis of the created ashes. The research of the grain composition was conducted by using the “Fritsch” apparatus. On the base of the grain composition, the surface area of ashes under investigation was determined, whereas the density was determined by using the helium pycnometer. The purpose of the research was to determine how the properties of ashes are changed and if the differences allow to use these ashes in future.

  4. Effects of Ni vacancy, Ni antisite, Cr and Pt on the third-order elastic constants and mechanical properties of NiAl

    KAUST Repository

    Wu, Shaohua

    2014-12-01

    Effects of Ni vacancy, Ni antisite in Al sublattice, Cr in Al sublattice, Pt in Ni sublattice on the second-order elastic constants (SOECs) and third-order elastic constants (TOECs) of the B2 NiAl have been investigated using the first-principles methods. Lattice constant and the SOECs of NiAl are in good agreement with the previous results. The brittle/ductile transition map based on Pugh ratio G/B and Cauchy pressure Pc shows that Ni antisite, Cr, Pt and pressure can improve the ductility of NiAl, respectively. Ni vacancy and lower pressure can enhance the Vickers hardness Hv of NiAl. The density of states (DOS) and the charge density difference are also used to analysis the effects of vacancy, Ni antisite, Cr and Pt on the mechanical properties of NiAl, and the results are in consistent with the transition map. © 2014 Elsevier Ltd. All rights reserved.

  5. Improvement in elastic properties of CuAl{sub 0.4}Fe{sub 1.6}O{sub 4} spinel ferrite by rapid thermal cooling

    Energy Technology Data Exchange (ETDEWEB)

    Modi, K. B., E-mail: kunalbmodi2003@yahoo.com; Shah, S. J., E-mail: kunalbmodi2003@yahoo.com; Pathak, T. K., E-mail: kunalbmodi2003@yahoo.com; Vasoya, N. H., E-mail: kunalbmodi2003@yahoo.com; Lakhani, V. K., E-mail: kunalbmodi2003@yahoo.com [Department of Physics, Saurashtra University, Rajkot-360005 (India); Yahya, A. K. [School of Physics and Materials Studies, University Technology MARA, 40450 Shah Alam, Selangor (Malaysia)

    2014-04-24

    The elastic properties of spinel ferrite composition, CuAl{sub 0.4}Fe{sub 1.6}O{sub 4}, quenched from final sintering temperature of 1373 K to liquid nitrogen temperature (∼ 80K) have been studied by means of X-ray powder diffractometry and pulse echo-overlap technique (9 MHz) at 300 K. The magnitude of elastic constants is found to enhance by 15% compared to slowly-cooled counterpart. The observed mechanical strengthening has been discussed in the light of compressive stress on the surface, with tensile stresses at interior regions and corresponding changes in structural parameters. The B{sub o}/G{sub o} ratio indicates the brittle nature of CuAl{sub 0.4}Fe{sub 1.6}O{sub 4}.

  6. First principles study on structural, electronic, elastic and mechanical properties of RuAl1-xGex alloys using special quasirandom structure

    Science.gov (United States)

    Fatima, Bushra; Acharya, Nikita; Chouhan, Sunil Singh; Sanyal, Sankar P.

    2013-06-01

    We developed the special quasirandom structure to study the structural, electronic, elastic and mechanical properties of RuAl1-xGex for different composition (x= 0.25, 0.50, 0.75 and 1) using Density Functional (FP-LAPW) method. The exchange and correlation potential is treated by the generalized gradient approximation. The values of elastic constant at ambient pressure are also reported. The ductility of these compounds has been analyzed using Pugh rule and Cauchy's pressure. From this study we found that RuAl is brittle while all its Ge doped alloys are ductile and RuAl0.25Ge0.75 is found to be the most ductile. The band structure of RuAl and its alloys are also reported.

  7. A pseudo-elastic effective material property representation of the costal cartilage for use in finite element models of the whole human body.

    Science.gov (United States)

    Forman, Jason L; de Dios, Eduardo del Pozo; Kent, Richard W

    2010-12-01

    Injury-predictive finite element (FE) models of the chest must reproduce the structural coupling behavior of the costal cartilage accurately. Gross heterogeneities (the perichondrium and calcifications) may cause models developed based on local material properties to erroneously predict the structural behavior of cartilage segments. This study sought to determine the pseudo-elastic effective material properties required to reproduce the structural behavior of the costal cartilage under loading similar to what might occur in a frontal automobile collision. Twenty-eight segments of cadaveric costal cartilage were subjected to cantilever-like, dynamic loading. Three limited-mesh FE models were then developed for each specimen, having element sizes of 10 mm (typical of current whole-body FE models), 3 mm, and 2 mm. The cartilage was represented as a homogeneous, isotropic, linear elastic material. The elastic moduli of the cartilage models were optimized to fit the anterior-posterior (x-axis) force versus displacement responses observed in the experiments. For a subset of specimens, additional model validation tests were performed under a second boundary condition. The pseudo-elastic effective moduli ranged from 4.8 to 49 MPa, with an average and standard deviation of 22 ± 13.6 MPa. The models were limited in their ability to reproduce the lateral (y-axis) force responses observed in the experiments. The prediction of the x-axis and y-axis forces in the second boundary condition varied. Neither the effective moduli nor the model fit were significantly affected (Student's t-test, p representation of the costal cartilage in whole-body FE models where these heterogeneities cannot be modeled distinctly.

  8. Effect of boron waste on the properties of mortar and concrete.

    Science.gov (United States)

    Topçu, Iker Bekir; Boga, Ahmet Raif

    2010-07-01

    Utilization of by-products or waste materials in concrete production are important subjects for sustainable development and industrial ecology concepts. The usages as mineral admixtures or fine aggregates improve the durability properties of concrete and thus increase the economic and environmental advantages for the concrete industry. The effect of clay waste (CW) containing boron on the mechanical properties of concrete was investigated. CW was added in different proportions as cement additive in concrete. The effect of CW on workability and strength of concrete were analysed by fresh and hardened concrete tests. The results obtained were compared with control concrete properties and Turkish standard values. The results showed that the addition of CW had a small effect upon the workability of the concrete but an important effect on the reduction of its strength. It was observed that strength values were quite near to that of control concrete when not more than 10% CW was used in place of cement. In addition to concrete specimens, replacing cement with CW produced mortar specimens, which were investigated for their strength and durability properties. The tests of SO( 4) (2-) and Cl(-) effect as well as freeze-thaw behaviour related to the durability of mortar were performed. Consequently, it can be said that some improvements were obtained in durability properties even if mechanical properties had decreased with increasing CW content.

  9. Comment on “Structural, elastic, electronic, magnetic and optical properties of RbSrX (C, SI, Ge) half-Heusler compounds”

    Energy Technology Data Exchange (ETDEWEB)

    Jalilian, Jaafar, E-mail: jaafarjalilian@gmail.com [Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Motiepour, Pouria [Electrical Engineering Department, Technical and Vocational University, Kermanshs (Iran, Islamic Republic of)

    2015-12-15

    In a recent article by Ahmad et al. (2015) [1] structural, elastic, electronic, magnetic and optical properties of RbSrX (C, Si, Ge) half-Heusler compounds have been studied by the first principles calculations. After studying this article, we found that there are some physical and computational mistakes in electronic and optical properties sections. In investigating optical properties, they did not consider intraband transitions contribution in complex dielectric function term, while this term has significant effect on optical spectra for half-metallic materials. - Highlights: • The spin up channel is more occupied than the spin down channel. • The intraband transition has remarkable effects on optical properties of half-metallic materials. • The intraband transitions increase reflectance in low energy ranges.

  10. A Non-Linear Finite Element Model for the Determination of Elastic and Thermal Properties of Nanocomposites

    Science.gov (United States)

    2009-04-01

    is presented in Figure 10. 38 Start V — Calculate Stiff Matrices in Each Element Due to Nanotubes V — Initialize Sress , Strain, and Elastic...Introduction to the FEM and Adaptive Error Analysis for Engineering Students , Elsevier Butterworth- Heinemann, 2005. [59] C.S. Desai and J.F. Abel

  11. Elastic and optical properties of GexSe2Sb1− x (0. 0≤ x≤ 1. 0 ...

    Indian Academy of Sciences (India)

    ... E g ) were investigated with high accuracy. The optically determined bulk modulus of these glasses was in good agreement with that elastically investigated. The obtained results were discussed in terms of the changes in the glass density, electronegativity and electronic polarizability with the variation in antimony content.

  12. The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.

    Science.gov (United States)

    Daszkiewicz, Karol; Maquer, Ghislain; Zysset, Philippe K

    2017-06-01

    Boundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58 and 15.87 mm) were cropped from [Formula: see text] scans of femoral heads and vertebral bodies. They were converted into [Formula: see text] models and their stiffness tensor was established via six uniaxial and shear load cases. PMUBCs- and KUBCs-based tensors were determined for each sample. "In situ" stiffness tensors were also evaluated for the embedded configuration, i.e. when the loads were transmitted to the samples via a layer of trabecular bone. The Zysset-Curnier model accounting for bone volume fraction and fabric anisotropy was fitted to those stiffness tensors, and model parameters [Formula: see text] (Poisson's ratio) [Formula: see text] and [Formula: see text] (elastic and shear moduli) were compared between sizes. BCs and sample size had little impact on [Formula: see text]. However, KUBCs- and PMUBCs-based [Formula: see text] and [Formula: see text], respectively, decreased and increased with growing size, though convergence was not reached even for our largest samples. Both BCs produced upper and lower bounds for the in situ values that were almost constant across samples dimensions, thus appearing as an approximation of the effective properties. PMUBCs seem also appropriate for mimicking the trabecular core, but they still underestimate its elastic properties (especially in shear) even for nearly orthotropic samples.

  13. Changes in morphological and elastic properties of patellar tendon in athletes with unilateral patellar tendinopathy and their relationships with pain and functional disability.

    Directory of Open Access Journals (Sweden)

    Zhi Jie Zhang

    Full Text Available Patellar tendinopathy (PT is one of the most common knee disorders among athletes. Changes in morphology and elasticity of the painful tendon and how these relate to the self-perceived pain and dysfunction remain unclear.To compare the morphology and elastic properties of patellar tendons between athlete with and without unilateral PT and to examine its association with self-perceived pain and dysfunction.In this cross-sectional study, 33 male athletes (20 healthy and 13 with unilateral PT were enrolled. The morphology and elastic properties of the patellar tendon were assessed by the grey and elastography mode of supersonic shear imaging (SSI technique while the intensity of pressure pain, self-perceived pain and dysfunction were quantified with a 10-lb force to the most painful site and the Victorian Institute of Sport Assessment-patella (VISA-P questionnaire, respectively.In athletes with unilateral PT, the painful tendons had higher shear elastic modulus (SEM and larger tendon than the non-painful side (p<0.05 or the dominant side of the healthy athletes (p<0.05. Significant correlations were found between tendon SEM ratio (SEM of painful over non-painful tendon and the intensity of pressure pain (rho  = 0.62; p = 0.024, VISA-P scores (rho  = -0.61; p = 0.026, and the sub-scores of the VISA-P scores on going down stairs, lunge, single leg hopping and squatting (rho ranged from -0.63 to -0.67; p<0.05.Athletes with unilateral PT had stiffer and larger tendon on the painful side than the non-painful side and the dominant side of healthy athletes. No significant differences on the patellar tendon morphology and elastic properties were detected between the dominant and non-dominant knees of the healthy control. The ratio of the SEM of painful to non-painful sides was associated with pain and dysfunction among athletes with unilateral PT.

  14. The usage of plastic waste as a secondary raw material for the modification of sandcrete properties

    Science.gov (United States)

    Klovas, A.; Daukšys, M.; Venčkauskas, L.

    2015-03-01

    Recently the usage of various industry wastes as a secondary raw material tends to increase its relevancy. One of possible options to decrease the amount of waste is to use them to produce new products or materials. The operation of various secondary raw materials (tire rubber, tire cord, ground glass shards, ground ceramic waste products) during the concrete mixture preparation allows to change its as well as cured concrete properties. Recently polymer and steel fibers are used for concrete reinforcement. This study analyses the usage possibility of plastic shavings for the reinforcement of concrete. The technological properties of cement slurry (sand, fraction of 0/4 and 10 kg/m3, 15 kg/m3 and 20 kg/m3 of plastic shavings) as well as mechanical, physical and porosity properties of cured sandcrete were established during the experimental research. The geometric characteristics of mill-shredded plastic shavings were established. Experimental results revealed that the usage of plastic shavings decreased slurry slump and density. The minor decrease of cured sandcrete density (~2200 kg/m3) was noticed with the addition of plastic shavings within the limits of 10 - 20 kg/m3. The flexural strength of cured sandcrete increased from 36 % to 57 % compared with reference specimen (without plastic shavings). The dependence of flexural force and deflection was obtained. Study revealed that the residual strength after crack opening is bigger with the usage of plastic shavings as a secondary raw material compared with reference specimen.

  15. Effect of steatite waste additions on the physical and mechanical properties of clay composites

    Directory of Open Access Journals (Sweden)

    Túlio Hallak Panzera

    2010-12-01

    Full Text Available Mineral rock wastes are being widely investigated due to possible damage to the environment when discarded indiscriminately in the nature, but also because of their great potential as ceramic raw materials. This work aims to study the effect of steatite particle additions on the mechanical properties of clay composites. A comprehensive series of experiments have been conducted to assess the influence of: steatite particle size, steatite fraction and compacting pressure on the performance of clay composites. The composite of superior properties was manufactured with 20 wt. (% of steatite, 100-200 US-Tyler of steatite particle size and 30 MPa of compacting pressure.

  16. Survey of creep properties of copper intended for nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Andersson-Oestling, Henrik C.M. (Swerea KIMAB AB, Stockholm (Sweden)); Sandstroem, Rolf (Materials Science and Engineering, School of Industrial Engineering and Management, Royal Inst. of Technology (KTH), Stockholm (Sweden))

    2009-12-15

    Creep in copper for application in canisters for nuclear waste disposal is surveyed. The importance of phosphorus doping to obtain adequate properties is demonstrated experimentally as well as explained theoretically. Creep tests results for electron beam and friction stir welds are compared. The latter type of welds has properties that are close to those of parent metal. The relation between slow strain rate tensile and creep is described. Fundamental constitutive equations are presented that are suitable for finite element modelling. These equations are used to simulate creep deformation in canisters

  17. Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Eduardo Sadot Herrera-Sosa

    2014-01-01

    Full Text Available In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16% are compensated with the use of high concentration of waste tire particles (30%, which ensures that the concrete will not significantly increase the cost.

  18. Thermal and physical property determination for IONSIV/256 IE-911 crystalline silicotitanate and Savannah River Site waste simulant solutions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-12-08

    This document describes physical and thermophysical property determinations that were made in order to resolve questions associated with the decontamination of Savannah River Site waste streams using ion exchange on crystalline silicotitanate.

  19. A general methodology for inverse estimation of the elastic and anelastic properties of anisotropic open-cell porous materials—with application to a melamine foam

    Science.gov (United States)

    Cuenca, Jacques; Van der Kelen, Christophe; Göransson, Peter

    2014-02-01

    This paper proposes an inverse estimation method for the characterisation of the elastic and anelastic properties of the frame of anisotropic open-cell foams used for sound absorption. A model of viscoelasticity based on a fractional differential constitutive equation is used, leading to an augmented Hooke's law in the frequency domain, where the elastic and anelastic phenomena appear as distinctive terms in the stiffness matrix. The parameters of the model are nine orthotropic elastic moduli, three angles of orientation of the material principal directions and three parameters governing the anelastic frequency dependence. The inverse estimation consists in numerically fitting the model on a set of transfer functions extracted from a sample of material. The setup uses a seismic-mass measurement repeated in the three directions of space and is placed in a vacuum chamber in order to remove the air from the pores of the sample. The method allows to reconstruct the full frequency-dependent complex stiffness matrix of the frame of an anisotropic open-cell foam and in particular it provides the frequency of maximum energy dissipation by viscoelastic effects. The characterisation of a melamine foam sample is performed and the relation between the fractional-derivative model and other types of parameterisations of the augmented Hooke's law is discussed.

  20. Comfort and Functional Properties of Far-Infrared/Anion-Releasing Warp-Knitted Elastic Composite Fabrics Using Bamboo Charcoal, Copper, and Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Ting-Ting Li

    2016-02-01

    Full Text Available Elastic warp-knitted composite fabrics with far-infrared emissivity and an anion-releasing property were prepared using bamboo charcoal (BC, copper (Cu, and phase-change material (PCM. The functional composite fabric, which was composed of self-made complex yarns with various twisting degrees and material composition, were created using a rotor twister and ring-spinning technique. The fabric structure was diversified by the feeding modes of weft yarn into a crochet-knitting machine. The twist number of complex yarns was optimized by tensile tenacity, twist contraction, and hairiness, and analysis showed that twisting at 12 twists per inch produced the highest tensile tenacity and appropriate twist contraction and hairiness. Comfort evaluation showed that the elastic composite fabrics with BC weft yarns exhibited higher water–vapor transmission rate and air permeability, reaching 876 g/m2∙ day and 73.2 cm3/s/cm2, respectively. Three structures of composite fabric with various weft yarns had >0.85 ε far-infrared emissivity and 350–420 counts/cm3 anion amount. The prepared elastic warp-knitted fabrics can provide a comfortable, dry, and breathable environment to the wearer and can thus be applied as health-care textiles in the future.

  1. A general methodology for inverse estimation of the elastic and anelastic properties of anisotropic open-cell porous materials—with application to a melamine foam

    Energy Technology Data Exchange (ETDEWEB)

    Cuenca, Jacques, E-mail: jcuenca@kth.se; Van der Kelen, Christophe; Göransson, Peter [Marcus Wallenberg Laboratory for Sound and Vibration Research, Royal Institute of Technology (KTH), Teknikringen 8, SE-10044 Stockholm (Sweden)

    2014-02-28

    This paper proposes an inverse estimation method for the characterisation of the elastic and anelastic properties of the frame of anisotropic open-cell foams used for sound absorption. A model of viscoelasticity based on a fractional differential constitutive equation is used, leading to an augmented Hooke's law in the frequency domain, where the elastic and anelastic phenomena appear as distinctive terms in the stiffness matrix. The parameters of the model are nine orthotropic elastic moduli, three angles of orientation of the material principal directions and three parameters governing the anelastic frequency dependence. The inverse estimation consists in numerically fitting the model on a set of transfer functions extracted from a sample of material. The setup uses a seismic-mass measurement repeated in the three directions of space and is placed in a vacuum chamber in order to remove the air from the pores of the sample. The method allows to reconstruct the full frequency-dependent complex stiffness matrix of the frame of an anisotropic open-cell foam and in particular it provides the frequency of maximum energy dissipation by viscoelastic effects. The characterisation of a melamine foam sample is performed and the relation between the fractional-derivative model and other types of parameterisations of the augmented Hooke's law is discussed.

  2. Fabric and elastic properties of antigorite, mica and amphibole-rich rocks and implications for the tectonic interpretation of seismic anisotropy

    Science.gov (United States)

    Shao, Tongbin

    The knowledge of seismic and elastic properties of polycrystalline rocks, which are representative of rocks currently being deformed at depth, under high pressure and temperature conditions is fundamental for geological interpretation of in-situ seismic data (e.g., reflections, refractions, received functions, tomography, and shear-wave splitting) and for establishing lithospheric structure and composition models. Through seismic properties measurements by directing high frequency waves at oriented rock samples and calculations from the crystallographic preferred orientation (CPO) measurements of minerals in polished rock samples using electron backscatter diffusion (EBSD) techniques, this thesis aims to better understand how the seismic and elastic properties [e.g., compressional and shear-wave velocities (Vp and Vs), anisotropy, and elastic moduli] of main rocks under confining pressure are influenced by their chemical and modal compositions, microstructures (e.g., foliation and lineation), and CPO of anisotropic minerals, and to interpret in situ seismic data observed in Tibetan Plateau and oceanic subduction zone using these data. This thesis consists of five chapters. Chapter 1 addresses the framework of calculation of seismic properties, with focus on basic principles of elasticity, mixture rules, and seismic properties of rock-forming minerals. Then it introduces three main groups of techniques for measuring rock seismic property, and describes the experimental details used in this study. Also, this chapter provides an overview on the source of seismic anisotropy in the lithosphere. Chapter 2 deals with seismic and elastic properties of 15 antigorite serpentinite samples measured at hydrostatic pressures up to 650 MPa, and with CPO-based calculation of 3D seismic properties of 11 samples. These data provide a new calibration for both seismic and fabric properties of antigorite, the only stable serpentine in subduction zones where temperature is above ˜300

  3. Assesment of hydraulics properties of technosoil constructed with waste material using Beerkan infiltration

    Science.gov (United States)

    Yilmaz, Deniz; Peyneau, Pierre-Emmanuel; Beaudet, Laure; Cannavo, Patrice; Sere, Geoffroy

    2017-04-01

    For the characterization of hydraulics soils functions, in situ infiltration experiments are commonly used. The BEST method based on the infiltration through a single ring is well suited for soils containing coarse material. Technosols built from Civil engineering waste material such as brick waste, concrete waste, track ballast and demolition rubble wastes contain large part of coarse material. In this work, different materials made of civil engineering wastes mixed with organic wastes are tested for greening applications in an urban environment using in situ lysimeters. Beerkan infiltrations experiments were performed on these technosols. Experimental data are used to estimate hydraulics properties through the BEST method. The results shows from a hydraulic point of view that studied technosols can achieve the role of urban soil for greening application. Five combinations of artefacts were tested either as "growing material" (one combination) or "structural material" (4 combinations) - as support for traffic. Structural materials consisted in 27 wt.% earth material, 60 wt.% mineral coarse material and 3 wt.% organic material. These constructed technosols were studied in situ using lysimeters under two contrasted climatic conditions in two sites in France (Angers, in northwestern France and Homécourt, in northeastern France). Constructed technosols exhibited high porosities (31-48 vol% for structural materials, 70 vol% for the growing material). The dry bulk density of the growing material is estimated to 0.66 kg/m3 and 1.59 kg/m3 for structural material. The particle size distribution analysis, involving manual sieving (> 2 mm) and complemented by a grain size analysis (method (2006) for the estimation of the shape parameter n of hydraulics functions (Van-Genuchten -Mualem, 1980). This n parameter was estimated to 2.23 for growing materials and 2.29 for structural materials. Beerkan infiltrations experiments data were inversed using the BEST method, the results

  4. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics.

    Science.gov (United States)

    Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J

    2015-01-01

    Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette

  5. Ab initio study of the structural, electronic, elastic and thermal properties of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Miloud Abid, O.; Yakoubi, A. [Laboratoire d’Etudes des Matériaux et Instrumentations Expérimentales, Université Djilali Liabes de Sidi Bel-Abbes, 22000 (Algeria); Tadjer, A. [Modeling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, Sidi Bel-Abbes (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique de la Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 (Algeria); Ahmed, R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Murtaza, G. [Materials Modeling Laboratory, Department of Physics, Islamia College University, Peshawar (Pakistan); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Azam, Sikander [New Technologies – Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic)

    2014-12-15

    Highlights: • The calculated structural parameters of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds are found in good agreement with the experimental data. • The structural and band structure calculation reveals that these compounds are ferromagnetic brittle metals. • The elastic and thermodynamic properties for the herein studied compounds are investigated for the first time. - Abstract: Intermetallic RMn{sub 2}Ge{sub 2} ternary compounds have attracted considerable attention from researchers in recent years because they show strong indications for novel magnetic characteristics and they have the potential to reveal the mechanism of superlattices. The study of the paramagnetic, ferromagnetic and antiferromagnetic phases affirms the strong dependence to the distance between atomic species in these compounds. In this study, we investigated the structural, elastic, electronic and thermodynamic properties of the intermetallic RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds. To carry out this study, we used the full potential (FP) linearized (L) augmented plane wave plus local orbitals (APW + lo), a scheme of calculations developed within the frame work of density functional theory (DFT). To incorporate the exchange correlation (XC) energy and corresponding potential into the total energy calculations, local density approximation (LDA) parameterized by Perdew and Wang is taken into account. Analysis of the density of states (DOS) profile illustrates the conducting nature of these intermetallic compounds; with a predominantly contribution from the R and Mn-d states. At ambient conditions, calculations for elastic constants (C{sub 11}, C{sub 12}, C{sub 13}, C{sub 44}, C{sub 33} and C{sub 66}) are also performed, which point to their brittle character. In addition, the quasi harmonic Debye model was used to predict the thermal properties, together with relative expansion coefficients and heat capacity.

  6. Dynamic Properties and Fatigue Life of Stone Mastic Asphalt Mixtures Reinforced with Waste Tyre Rubber

    Directory of Open Access Journals (Sweden)

    Nuha Salim Mashaan

    2013-01-01

    Full Text Available Today, virgin polymer modified asphalt mixes are comparatively more expensive for road pavement. One way to reduce the expense of such construction and to make it more convenient is the application of inexpensive polymer, such as waste polymer. The primary aim of this study was to investigate the effect of adding waste tyre rubber (crumb rubber modifier (CRM on the stiffness and fatigue properties of stone mastic asphalt (SMA mixtures. Various percentages of waste CRM with size of 0.60 mm were added to SMA mixtures. Indirect tensile stiffness modulus test was conducted at temperatures of 5, 25, and 40°C. Indirect tensile fatigue test was conducted at three different stress levels (2000, 2500, and 3000 N. The results show that the stiffness modulus of reinforced SMA samples containing various contents of CRM is significantly high in comparison with that of nonreinforced samples, and the stiffness modulus of reinforced samples is in fact less severely affected by the increased temperature compared to the nonreinforced samples. Further, the results show that CRM reinforced SMA mixtures exhibit significantly higher fatigue lives compared to the nonreinforced mixtures help in and promotion of sustainable technology by recycling of waste materials in much economical and environmental-friendly manner.

  7. Effects of biochar, waste water irrigation and fertilization on soil properties in West African urban agriculture.

    Science.gov (United States)

    Häring, Volker; Manka'abusi, Delphine; Akoto-Danso, Edmund K; Werner, Steffen; Atiah, Kofi; Steiner, Christoph; Lompo, Désiré J P; Adiku, Samuel; Buerkert, Andreas; Marschner, Bernd

    2017-09-06

    In large areas of sub-Saharan Africa crop production must cope with low soil fertility. To increase soil fertility, the application of biochar (charred biomass) has been suggested. In urban areas, untreated waste water is widely used for irrigation because it is a nutrient-rich year-round water source. Uncertainty exists regarding the interactions between soil properties, biochar, waste water and fertilization over time. The aims of this study were to determine these interactions in two typical sandy, soil organic carbon (SOC) and nutrient depleted soils under urban vegetable production in Tamale (Ghana) and Ouagadougou (Burkina Faso) over two years. The addition of biochar at 2 kg m-2 made from rice husks and corn cobs initially doubled SOC stocks but SOC losses of 35% occurred thereafter. Both biochar types had no effect on soil pH, phosphorous availability and effective cation exchange capacity (CEC) but rice husk biochar retained nitrogen (N). Irrigation with domestic waste water increased soil pH and exchangeable sodium over time. Inorganic fertilization alone acidified soils, increased available phosphorous and decreased base saturation. Organic fertilization increased SOC, N and CEC. The results from both locations demonstrate that the effects of biochar and waste water were less pronounced than reported elsewhere.

  8. MECHANICAL AND THERMAL PROPERTIES OF WASTE BIO-POLYMER COMPOUND BY HOT COMPRESSION MOLDING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    M. Khairul Zaimy A. G.

    2013-12-01

    Full Text Available The demand for bio-polymer compound (BPC has attracted attention in various applications from industrial to medical. Therefore, the mechanical and thermal stability properties of recycling industrial waste BPC are very important to investigate. The waste BPC for this study is based on a mixture of hydroxylated waste cooking oil with hardeners to produce waste bio-polymer foam (WBF. The granulate of WBF was cast into the mold until all spaces were evenly filled and compacted into a homogeneous shape and thickness at 30–45 bar for 2 hours using hot compression molding. This method of BPC fabrication results in a tensile and flexural strength of 4.89 MPa and 18.08 MPa respectively. Meanwhile, the thermal stability of laminated BPC was conducted using a thermal gravimetric analyzer (TGA, and the first degradation of the soft segment occurred at 263°C, then subsequently the second degradation occurred at 351°C and the last at 416°C.

  9. Effect of Coulomb interactions and Hartree-Fock exchange on structural, elastic, optoelectronic and magnetic properties of Co{sub 2}MnSi Heusler: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Lantri, T. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bentata, S., E-mail: sam_bentata@yahoo.com [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bouadjemi, B.; Benstaali, W. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Bouhafs, B. [Modelling and Simulation in Materials Science Laboratory, Djillali Liabès University of Sidi Bel-Abbès, 22000 Sidi Bel-Abbes (Algeria); Abbad, A. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria); Modelling and Simulation in Materials Science Laboratory, Djillali Liabès University of Sidi Bel-Abbès, 22000 Sidi Bel-Abbes (Algeria); Zitouni, A. [Laboratory of Technology and Solid’s Properties, Faculty of Sciences and Technology, Abdelhamid Ibn Badis University, BP 227, Mostaganem 27000 (Algeria)

    2016-12-01

    Using the first-principle calculations, we have investigated the structural, elastic, optoelectronic and magnetic properties of Co{sub 2}MnSi Heusler alloy. Based on the density functional theory (DFT) and hiring the full-potential linearized augmented plane wave (FP-LAPW) method, we have used five approaches: the Hybrid on-site exact exchange, the Local Spin Density Approximation (LSDA), the LSDA+U, the Generalized Gradient Approximation GGA and GGA+U; where the Hubbard on-site Coulomb interaction correction U is calculated by constraint local density approximation for Co and Mn atoms. Our results show that the highly-ordered Co{sub 2}MnSi alloy is a ductile, stiff and anisotropic material. It has a half-metallic ferromagnetic character with an integer magnetic moment of 5 µB which is in good agreement with the Slater-Pauling rule. - Highlights: • Each approach gives a half magnetic compound. • EECE gives the largest gap. • Elastic properties show a stiff, ductile and anisotropic material. • Electronic properties are similar for the five approaches. • Total magnetic moment is the same for the five approaches (5 µB).

  10. Theoretical investigation of the electronic structure, optical, elastic and thermodynamics properties of a newly binary boron nitride (T-B{sub 3}N{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shibo, E-mail: zsb@cdut.edu.cn [Network and Educational Technology Center, Chengdu University of Technology, Chengdu 610059 (China); Long, Jianping [College of Materials and Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu 610059 (China)

    2015-02-15

    The ultrasoft pseudopotential planewave (UPPW) within density functional theory (DFT) has been used to investigate the electronic structure, optical, elastic and thermodynamics properties of newly binary boron nitride (T-B{sub 3}N{sub 3}). The calculated lattice parameters are in good agreement with previous theoretical results and deviated are less than 0.4%. The electronic structure showed that the T-B{sub 3}N{sub 3} is metallic, and the optical spectra exhibit a noticeable anisotropy. The static dielectric constants, optical permittivity constants and the elastic properties are calculated. From our results, we observe that T-B{sub 3}N{sub 3} is mechanically unstable and ductile. The entropy, enthalpy, free energy, heat capacity and Debye temperature of T-B{sub 3}N{sub 3} was obtained. Up to now, there are no available experimental data about those properties. The results obtained in the present paper could provide important reference data for future studies.

  11. Wave field characterization for non-destructive assessment of elastic properties using laser-acoustic sources in fluids and eye related tissues

    Science.gov (United States)

    Windisch, T.; Schubert, F.; Köhler, B.; Spörl, E.

    2010-03-01

    The age-related changes in the visco-elastic properties of the human lens are discussed with respect to presbyopia for a long time. All known measurement techniques are based on extracted lenses or are damaging the tissue. Hence, in vivo studies of lens hardness are not possible at the moment. To close this gap in lens diagnostics this project deals with an approach for a non-contact laser-acoustic characterization technique. Laser-generated wave fronts are reflected by the tissue interfaces and are also affected by the visco-elastic properties of the lens tissue. After propagating through the eye, these waves are recorded as corneal vibrations by laser vibrometry. A systematic analysis of amplitude and phase of these signals and the wave generation process shall give information about the interface locations and the tissues viscoelastic properties. Our recent studies on extracted porcine eyes proved that laser-acoustic sources can be systematically used for non-contacting generation and recording of ultrasound inside the human eye. Furthermore, a specific numerical model provides important contributions to the understanding of the complex wave propagation process. Measurements of the acoustic sources support this approach. Future investigations are scheduled to answer the question, whether this novel technique can be directly used during a laser surgery for monitoring purposes and if a purely diagnostic approach, e.g. by excitation in the aqueous humor, is also possible. In both cases, this technique offers a promising approach for non-contact ultrasound based eye diagnostics.

  12. Study of pressure variation effect on structural, opto-electronic, elastic, mechanical, and thermodynamic properties of SrLiF3

    Science.gov (United States)

    Erum, Nazia; Iqbal, Muhammad Azhar

    2017-11-01

    The structural, electronic, elastic, optical and thermodynamic properties of cubic fluoroperovskite SrLiF3 at ambient and high-pressure are investigated by using first-principles total energy calculations within the framework of Generalized Gradient Approximation (GGA), combined with Quasi-harmonic Debye model in which the phonon effects are considered. The pressure effects are determined in the range of 0-50 GPa, in which cubic stability of SrLiF3 fluoroperovskite remains valid. The computed lattice parameters agree well with experimental and previous theoretical results. Decrease in lattice constant and bonds length is observed with the increase in pressure from 0 to 50 GPa. The effect of increase in pressure on electronic band structure calculations with GGA and GGA plus Tran-Blaha modified Becke-Johnson (TB-mBJ) potential reveals a predominant characteristic associated with widening of bandgap. The influence of pressure on elastic constants and their related mechanical parameters have been discussed in detail. All the calculated optical properties such as the complex dielectric function Ԑ(ω), optical conductivity σ(ω), energy loss function L(ω), absorption coefficient α(w), refractive index n (ω), reflectivity R (ω), and effective number of electrons neff, via sum rules shift towards the higher energies under the application of pressure. Moreover, important thermodynamic properties heat capacities (Cp and Cv), volume expansion coefficient (α), and Debye temperature (θD) are predicted successfully in the wide temperature and pressure ranges.

  13. Structural, electronic, elastic and magnetic properties of RuFe{sub 3}N and OsFe{sub 3}N: A first principle study

    Energy Technology Data Exchange (ETDEWEB)

    Puvaneswari, S. [Department of Physics, E.M.G. Yadava Women’s College, Madurai, Tamilnadu-625014 (India); Priyanga, G. Sudha; Rajeswarapalanichamy, R., E-mail: rajeswarapalanichamy@gmail.com; Santhosh, M. [Department of Physics, N.M.S.S.V.N college, Madurai, Tamilnadu-625019 (India)

    2015-06-24

    The structural, electronic, elastic and magnetic properties of the perovskite structure of RuFe{sub 3}N, and OsFe{sub 3}N have been reported using the VASP within the gradient generalized approximation. Total energy calculations are performed using both spin and non-spin polarized calculations and it is found that, at ambient pressure both RuFe{sub 3}N and OsFe{sub 3}N are stable in ferromagnetic phase. The electronic structure reveals that both RuFe{sub 3}N and OsFe{sub 3}N are metallic in nature at ambient pressure.

  14. Influence of Size Effect on the Electronic and Elastic Properties of Graphane Nanoflakes: Quantum Chemical and Empirical Investigations

    Directory of Open Access Journals (Sweden)

    A. S. Kolesnikova

    2015-01-01

    Full Text Available By application of empirical method it is found that graphene nanoflake (graphane saturated by hydrogen is not elastic material. In this case, the modulus of the elastic compression of graphane depends on its size, allowing us to identify the linear parameters of graphane with maximum Young’s modulus for this material. The electronic structure of graphane nanoflakes was calculated by means of the semiempirical tight-binding method. It is found that graphane nanoflakes can be characterized as dielectric. The energy gap of these particles decreases with increasing of the length tending to a certain value. At the same time, the ionization potential of graphane also decreases. A comparative analysis of the calculated values with the same parameters of single-walled nanotubes is performed.

  15. The influence of closed brine pockets and permeable brine channels on the thermo-elastic properties of saline ice

    Science.gov (United States)

    Marchenko, Aleksey; Lishman, Ben

    2017-02-01

    A model of the thermo-elastic behaviour of saline ice is formulated, and model solutions describing thermo-elastic waves (TEW) propagating into a half-space of the ice are investigated. The model is based on a proposal that saline ice is a matrix, which encompasses both closed brine pockets and permeable channels filled with brine. Experiments on the thermal expansion of saline ice samples, and on TEW in saline ice, have been performed in the cold laboratories of the University Centre in Svalbard and in University College London. The experimental data are compared with theoretical conclusions. The experimental data support our hypothesis that the brine in saline ice is divided between closed pockets and open, permeable channels. This article is part of the themed issue 'Microdynamics of ice'.

  16. Growth mechanism, dielectric, elastic and thermal properties of zinc cadmium thiocyanate crystal as a potential piezoelectric crystal

    Science.gov (United States)

    Lü, Yadong; Liu, Xitao; Wang, Xinqiang; Gao, Zeliang; Yin, Xin; Yuan, Kangkang; Xu, Chonghe; Wang, Lin; Zhang, Guanghui; Zhu, Luyi; Xu, Dong

    2017-10-01

    Bulk single crystals of zinc cadmium thiocyanate, ZnCd(SCN)4 (ZCTC) with dimensions of 51 × 15 × 12 and 28 × 13 × 12 mm3 have been obtained. Growth habits were investigated, two-dimensional nucleation growth mechanism and crystal twinning defect were observed from the as-grown crystals. The thermal diffusivities were measured, and then thermal conductivities were calculated with values decreasing from 1.3683 to 0.8739 Wṡm-1ṡK-1 and 0.8496 to 0.5356 Wṡm-1ṡK-1 as the temperature increasing from 303 to 423 K, along the a- and c-directions, respectively. The relative dielectric constants and elastic compliance constants at room temperature were determined. Meanwhile, first-principles calculation was used to calculate elastic constants.

  17. King post truss as a motif for internal structure of (meta)material with controlled elastic properties

    Science.gov (United States)

    Turco, Emilio; Giorgio, Ivan; Misra, Anil; dell'Isola, Francesco

    2017-10-01

    One of the most interesting challenges in the modern theory of materials consists in the determination of those microstructures which produce, at the macro-level, a class of metamaterials whose elastic range is many orders of magnitude wider than the one exhibited by `standard' materials. In dell'Isola et al. (2015 Zeitschrift für angewandte Mathematik und Physik 66, 3473-3498. (doi:10.1007/s00033-015-0556-4)), it was proved that, with a pantographic microstructure constituted by `long' micro-beams it is possible to obtain metamaterials whose elastic range spans up to an elongation exceeding 30%. In this paper, we demonstrate that the same behaviour can be obtained by means of an internal microstructure based on a king post motif. This solution shows many advantages: it involves only microbeams; all constituting beams are undergoing only extension or compression; all internal constraints are terminal pivots. While the elastic deformation energy can be determined as easily as in the case of long-beam microstructure, the proposed design seems to have obvious remarkable advantages: it seems to be more damage resistant and therefore to be able to have a wider elastic range; it can be realized with the same three-dimensional printing technology; it seems to be less subject to compression buckling. The analysis which we present here includes: (i) the determination of Hencky-type discrete models for king post trusses, (ii) the application of an effective integration scheme to a class of relevant deformation tests for the proposed metamaterial and (iii) the numerical determination of an equivalent second gradient continuum model. The numerical tools which we have developed and which are presented here can be readily used to develop an extensive measurement campaign for the proposed metamaterial.

  18. Influence of polyacrylic acid nanoparticles on the elastic properties of RBCs membranes in patients with diabetes mellitus type 2

    Czech Academy of Sciences Publication Activity Database

    Melnikova, G.B.; Kuzhel, N.S.; Tolstaya, T.N.; Konstantinova, E.E.; Drozd, E.S.; Shisko, O.N.; Mokhort, T.G.; Antonova, N.; Říha, Pavel; Kowalczuk, A.; Koseva, N.

    2015-01-01

    Roč. 29, č. 4 (2015), s. 12-19 ISSN 1313-2458 Institutional support: RVO:67985874 Keywords : red blood cells * nanoparticles * poly(acrylic acid) * elasticity modulus * atomic force microscopy Subject RIV: BK - Fluid Dynamics http://www.imbm.bas.bg/biomechanics/uploads/Archive2015-4/12-19_Melnikova-Konstantinova_et%20al_abstract-1_18.12.15.pdf

  19. Elastic Properties of Novel Co and CoNi Based Superalloys Determined through Bayesian Inference and Resonant Ultrasound Spectroscopy (Preprint)

    Science.gov (United States)

    2018-01-01

    accurately the liquidus and solidus temperatures) is intrinsic to the material and cannot be appre- ciably increased . This reality has spurred research and...atomic fraction of Co increased and Ni decreased. Elastic anisotropy (A) is also substantially increased , but only after Co becomes the dominant...a small average increase in A of 1.8% over the Ni-based alloy CMSX-4, Co-based alloys were an average of 11% more anisotropic than the CoNi-based

  20. Functional Elastic Knits Made of Bamboo Charcoal and Quick-Dry Yarns: Manufacturing Techniques and Property Evaluations

    Directory of Open Access Journals (Sweden)

    Jia-Horng Lin

    2017-12-01

    Full Text Available Conventional sportswear fabrics are functional textiles that can mitigate the impaired muscles caused by exercises for the wearers, but they can also cause discomfort and skin allergy. This study proposes combining two yarns to form functional composite yarns, by using a twisting or wrapping process. Moreover, a different twist number is used in order to adjust the performance of functional composite yarns. A crochet machine is used to make the functional composite yarns into functional elastic knits that are suitable for use in sportswear. The test results show that, in comparison to the non-processed yarns, using the twisted or wrapped yarns can considerably decrease the water vapor transmission rate of functional elastic knits by 38%, while also improving their far infrared emissivity by 13%, water absorption rate by 39%, and air permeability by 136%. In particular, the functional elastic knits that are made of B-wrapped yarns (bamboo charcoal- wrapped yarns, composed of 20 twists per inch, have the optimal diverse functions.