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Sample records for cellular solid behaviour

  1. Continuum representations of cellular solids

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  2. Advanced 3D Printers for Cellular Solids

    Science.gov (United States)

    2016-06-30

    SECURITY CLASSIFICATION OF: Final Report for DURIP grant W911NF-14-1-0416 This DURIP grant has allowed for the purchase of three 3D printers ...06-2016 1-Aug-2014 31-Dec-2015 Final Report: Advanced 3D printers for Cellular Solids The views, opinions and/or findings contained in this report are...Papers published in non peer-reviewed journals: Final Report: Advanced 3D printers for Cellular Solids Report Title Final Report for DURIP grant W911NF

  3. Cellular Automata Model for Elastic Solid Material

    Institute of Scientific and Technical Information of China (English)

    DONG Yin-Feng; ZHANG Guang-Cai; XU Ai-Guo; GAN Yan-Biao

    2013-01-01

    The Cellular Automaton (CA) modeling and simulation of solid dynamics is a long-standing difficult problem.In this paper we present a new two-dimensional CA model for solid dynamics.In this model the solid body is represented by a set of white and black particles alternatively positioned in the x-and y-directions.The force acting on each particle is represented by the linear summation of relative displacements of the nearest-neighboring particles.The key technique in this new model is the construction of eight coefficient matrices.Theoretical and numerical analyses show that the present model can be mathematically described by a conservative system.So,it works for elastic material.In the continuum limit the CA model recovers the well-known Navier equation.The coefficient matrices are related to the shear module and Poisson ratio of the material body.Compared with previous CA model for solid body,this model realizes the natural coupling of deformations in the x-and y-directions.Consequently,the wave phenomena related to the Poisson ratio effects are successfully recovered.This work advances significantly the CA modeling and simulation in the field of computational solid dynamics.

  4. Thermo-fluid behaviour of periodic cellular metals

    CERN Document Server

    Lu, Tian Jian; Wen, Ting

    2013-01-01

    Thermo-Fluid Behaviour of Periodic Cellular Metals introduces the study of coupled thermo-fluid behaviour of cellular metals with periodic structure in response to thermal loads, which is an interdisciplinary research area that requires a concurrent-engineering approach.  The book, for the first time, systematically adopts experimental, numerical, and analytical approaches, presents the fluid flow and heat transfer in periodic cellular metals under forced convection conditions, aiming to establish structure-property relationships for tailoring material structures to achieve properties and performance levels that are customized for defined multifunctional applications. The book, as a textbook and reference book, is intended for both academic and industrial people, including graduate students, researchers and engineers. Dr. Tian Jian Lu is a professor at the School of Aerospace, Xi’an Jiaotong University, Xi’an, China. Dr. Feng Xu is a professor at the Key Laboratory of Biomedical Information Engineering o...

  5. Amplification of cellular oncogenes in solid tumors

    Directory of Open Access Journals (Sweden)

    Ozkan Bagci

    2015-01-01

    Full Text Available The term gene amplification refers to an increase in copy number of a gene. Upregulation of gene expression through amplification is a general mechanism to increase gene dosage. Oncogene amplifications have been shown in solid human cancers and they are often associated with progression of cancer. Defining oncogene amplification is useful since it is used as a prognostic marker in clinical oncology nowadays, especially v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (HER2 targeted agents are used in breast cancer patients with high level of HER2 overexpression as a therapeutic approach. However, patients without HER2 overexpression do not appear to benefit from these agents. We concluded that determination of oncogene amplification in solid tumors is an important factor in treatment of human cancers with many unknowns. We have referred to PubMed and some databases to prepare this article.

  6. Phenomenological study of a cellular material behaviour under dynamic loadings

    Science.gov (United States)

    Bouix, R.; Viot, Ph.; Lataillade, J.-L.

    2006-08-01

    Polypropylene foams are cellular materials, which are often use to fill structures subjected to crash or violent impacts. Therefore, it is necessary to know and to characterise in experiments their mechanical behaviour in compression at high strain rates. So, several apparatus have been used in order to highlight the influence of strain rate, material density and also temperature. A split Hopkinson Pressure Bar has been used for impact tests, a fly wheel to test theses materials at medium strain rate and an electro-mechanical testing machine associated to a climatic chamber for temperature tests. Then, a rheological model has been used in order to describe the material behaviour. The mechanical response to compression of these foams presents three typical domains: a linear elastic step, a wide collapse plateau stress, which leads to a densification, which are related to a standard rheological model.

  7. Modeling effective viscosity reduction behaviour of solid suspensions

    Institute of Scientific and Technical Information of China (English)

    Wei En-Bo; Ji Yan-Ju; Zhang Jun

    2012-01-01

    Under a simple shearing flow,the effective viscosity of solid suspensions can be reduced by controlling the inclusion particle size or the number of inclusion particles in a unit volume.Based on the Stokes equation,the transformation field method is used to model the reduction behaviour of effective viscosity of solid suspensions theoretically by enlarging the particle size at a given high concentration of particles.With a lot of samples of random cubic particles in a unit cell,our statistical results show that at the same higher concentration,the effective viscosity of solid suspensions can be reduced by increasing the particle size or reducing the number of inclusion particles in a unit volume.This work discloses the viscosity reduction mechanism of increasing particle size,which is observed experimentally.

  8. The CORVET complex: compositions, function, and impact on cellular behaviour

    NARCIS (Netherlands)

    Jonker, CTH

    2016-01-01

    The endolysosomal system is positioned on the crossroad of the intracellular and extracellular environment and is therefore crucial to regulate many cellular processes. Proper function of the endolysosomal system greatly depends on the concept of membrane identity; the controlled protein and lipid

  9. Cell dipole behaviour revealed by ECM sub-cellular geometry

    Science.gov (United States)

    Mandal, Kalpana; Wang, Irène; Vitiello, Elisa; Orellana, Laura Andreina Chacòn; Balland, Martial

    2014-12-01

    Cells sense and respond to their mechanical environment by exerting forces on their surroundings. The way forces are modulated by extra-cellular matrix (ECM) properties plays a key role in tissue homoeostasis. Using highly resolved micropatterns that constrain cells into the same square envelope but vary the adhesive geometry, here we investigate how the adhesive micro-environment affects the architecture of actin cytoskeleton and the orientation of traction forces. Our data demonstrate that local adhesive changes can trigger orientational ordering of stress fibres throughout the cell, suggesting that cells are capable of integrating information on ECM geometry at the whole-cell level. Finally, we show that cells tend to generate highly polarized force pattern, that is, unidirectional pinching, in response to adequate adhesive conditions. Hence, the geometry of adhesive environment can induce cellular orientation, a process which may have significant implications for the formation and mechanical properties of tissues.

  10. Scale Effects on Solid Rocket Combustion Instability Behaviour

    Directory of Open Access Journals (Sweden)

    David R. Greatrix

    2011-01-01

    Full Text Available The ability to understand and predict the expected internal behaviour of a given solid-propellant rocket motor under transient conditions is important. Research towards predicting and quantifying undesirable transient axial combustion instability symptoms necessitates a comprehensive numerical model for internal ballistic simulation under dynamic flow and combustion conditions. A numerical model incorporating pertinent elements, such as a representative transient, frequency-dependent combustion response to pressure wave activity above the burning propellant surface, is applied to the investigation of scale effects (motor size, i.e., grain length and internal port diameter on influencing instability-related behaviour in a cylindrical-grain motor. The results of this investigation reveal that the motor’s size has a significant influence on transient pressure wave magnitude and structure, and on the appearance and magnitude of an associated base pressure rise.

  11. Predictive model to describe water migration in cellular solid foods during storage

    NARCIS (Netherlands)

    Voogt, J.A.; Hirte, A.; Meinders, M.B.J.

    2011-01-01

    BACKGROUND: Water migration in cellular solid foods during storage causes loss of crispness. To improve crispness retention, physical understanding of this process is needed. Mathematical models are suitable tools to gain this physical knowledge. RESULTS: Water migration in cellular solid foods

  12. Predictive model to describe water migration in cellular solid foods during storage

    NARCIS (Netherlands)

    Voogt, J.A.; Hirte, A.; Meinders, M.B.J.

    2011-01-01

    Background: Water migration in cellular solid foods during storage causes loss of crispness. To improve crispness retention, physical understanding of this process is needed. Mathematical models are suitable tools to gain this physical knowledge. Results: Water migration in cellular solid foods invo

  13. Predictive model to describe water migration in cellular solid foods during storage

    NARCIS (Netherlands)

    Voogt, J.A.; Hirte, A.; Meinders, M.B.J.

    2011-01-01

    BACKGROUND: Water migration in cellular solid foods during storage causes loss of crispness. To improve crispness retention, physical understanding of this process is needed. Mathematical models are suitable tools to gain this physical knowledge. RESULTS: Water migration in cellular solid foods invo

  14. Current perspectives on behavioural and cellular mechanisms of illness anorexia.

    Science.gov (United States)

    Asarian, Lori; Langhans, Wolfgang

    2005-12-01

    Here we review our current understanding of the integration of immune, neural, metabolic and endocrine signals involved in the generation of anorexia during acute infection, with the focus on anorexia elicited by peripheral administration of bacterial lipopolysaccharide (LPS). We chose to limit this review to peripheral LPS-anorexia because the mechanisms underlying this response may also be valid for anorexia during other types of acute or chronic infections, with slight differences in the duration of anorexia, levels of circulating concentrations of pro-inflammatory cytokines and hypermetabolism. Evidence so far indicates that LPS-anorexia is a complex response beneficial to host defence that involves both peripheral and central action of pro-inflammatory cytokines, other immune factors, such as prostanoids, and neurotransmitters, such as serotonin. One interesting characteristic of LPS-anorexia is its sexual differentiation, an aspect mainly mediated by the gonadal hormone estradiol. Understanding the behavioural and molecular mechanisms of LPS-anorexia may even provide useful leads for identifying mechanisms of eating disorders in humans.

  15. 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.

  16. On the behaviour characterization of metallic cellular materials under impact loading

    Science.gov (United States)

    Fang, Dai-Ning; Li, Yu-Long; Zhao, Han

    2010-12-01

    This paper reviews the common mechanical features of the metallic cellular material under impact loading as well as the characterization methods of such behaviours. The main focus is on the innovations of various testing methods at impact loading rates. Following aspects were discussed in details. (1) The use of soft nylon Hopkinson/Kolsky bar for an enhanced measuring accuracy in order to assess if there is a strength enhancement or not for this class of cellular materials under moderate impact loading; (2) The use of digital image correlations to determine the strain fields during the tests to confirm the existence of a pseudo-shock wave propagation inside the cellular material under high speed impact; (3) The use of new combined shear compression device to determine the loading envelop of cellular materials under impact multiaxial loadings.

  17. Digital Cellular Solid Pressure Vessels: A Novel Approach for Human Habitation in Space

    Science.gov (United States)

    Cellucci, Daniel; Jenett, Benjamin; Cheung, Kenneth C.

    2017-01-01

    It is widely assumed that human exploration beyond Earth's orbit will require vehicles capable of providing long duration habitats that simulate an Earth-like environment - consistent artificial gravity, breathable atmosphere, and sufficient living space- while requiring the minimum possible launch mass. This paper examines how the qualities of digital cellular solids - high-performance, repairability, reconfigurability, tunable mechanical response - allow the accomplishment of long-duration habitat objectives at a fraction of the mass required for traditional structural technologies. To illustrate the impact digital cellular solids could make as a replacement to conventional habitat subsystems, we compare recent proposed deep space habitat structural systems with a digital cellular solids pressure vessel design that consists of a carbon fiber reinforced polymer (CFRP) digital cellular solid cylindrical framework that is lined with an ultra-high molecular weight polyethylene (UHMWPE) skin. We use the analytical treatment of a linear specific modulus scaling cellular solid to find the minimum mass pressure vessel for a structure and find that, for equivalent habitable volume and appropriate safety factors, the use of digital cellular solids provides clear methods for producing structures that are not only repairable and reconfigurable, but also higher performance than their conventionally manufactured counterparts.

  18. Lightened plaster: alternative solutions to cellular solids addition

    Directory of Open Access Journals (Sweden)

    Del Río, M.

    2004-09-01

    Full Text Available The following paper pretends to analyze different processes in order to lightweighters gypsum as an alternative way at the cellular fillers addition, in order to establish the most suitable ones for the manufacture of plasterboard. Outstanding the process which uses foamings addition to lighten gypsum uses nowdays only to manufacture cellular concrete.

    En este artículo se presenta el análisis de diferentes procedimientos para aligerar la escayola, como alternativas a la adición de sólidos celulares, determinando los más adecuados para la realización de prefabricados. Dentro de estos procedimientos cabe destacar la adición de espumantes, hasta ahora sólo utilizados para la fabricación de hormigones celulares.

  19. Dispersion Behaviour of Silica Nanoparticles in Biological Media and Its Influence on Cellular Uptake.

    Science.gov (United States)

    Halamoda-Kenzaoui, Blanka; Ceridono, Mara; Colpo, Pascal; Valsesia, Andrea; Urbán, Patricia; Ojea-Jiménez, Isaac; Gioria, Sabrina; Gilliland, Douglas; Rossi, François; Kinsner-Ovaskainen, Agnieszka

    2015-01-01

    Given the increasing variety of manufactured nanomaterials, suitable, robust, standardized in vitro screening methods are needed to study the mechanisms by which they can interact with biological systems. The in vitro evaluation of interactions of nanoparticles (NPs) with living cells is challenging due to the complex behaviour of NPs, which may involve dissolution, aggregation, sedimentation and formation of a protein corona. These variable parameters have an influence on the surface properties and the stability of NPs in the biological environment and therefore also on the interaction of NPs with cells. We present here a study using 30 nm and 80 nm fluorescently-labelled silicon dioxide NPs (Rubipy-SiO2 NPs) to evaluate the NPs dispersion behaviour up to 48 hours in two different cellular media either supplemented with 10% of serum or in serum-free conditions. Size-dependent differences in dispersion behaviour were observed and the influence of the living cells on NPs stability and deposition was determined. Using flow cytometry and fluorescence microscopy techniques we studied the kinetics of the cellular uptake of Rubipy-SiO2 NPs by A549 and CaCo-2 cells and we found a correlation between the NPs characteristics in cell media and the amount of cellular uptake. Our results emphasize how relevant and important it is to evaluate and to monitor the size and agglomeration state of nanoparticles in the biological medium, in order to interpret correctly the results of the in vitro toxicological assays.

  20. A traffic flow cellular automaton model to considering drivers' learning and forgetting behaviour

    Institute of Scientific and Technical Information of China (English)

    Ding Jian-Xun; Huang Hai-Jun; Tian Qiong

    2011-01-01

    It is known that the commonly used NaSch cellular automaton (CA) model and its modifications can help explain the internal causes of the macro phenomena of traffic flow. However, the randomization probability of vehicle velocity used in these models is assumed to be an exogenous constant or a conditional constant, which cannot reflect the learning and forgetting behaviour of drivers with historical experiences. This paper further modifies the NaSch model by enabling the randomization probability to be adjusted on the bases of drivers' memory. The Markov properties of this modified model are discussed. Analytical and simulation results show that the traffic fundamental diagrams can be indeed improved when considering drivers' intelligent behaviour. Some new features of traffic are revealed by differently combining the model parameters representing learning and forgetting behaviour.

  1. Thermal behaviour of ESP ash from municipal solid waste incinerators.

    Science.gov (United States)

    Yang, Y; Xiao, Y; Wilson, N; Voncken, J H L

    2009-07-15

    Stricter environmental regulations demand safer treatment and disposal of incinerator fly ashes. So far no sound technology or a process is available for a sustainable and ecological treatment of the waste incineration ashes, and only partial treatment is practised for temporary and short-term solutions. New processes and technology need to be developed for comprehensive utilization and detoxification of the municipal solid waste (MSW) incinerator residues. To explore the efficiency of thermal stabilisation and controlled vitrification, the thermal behaviour of electrostatic precipitator (ESP) ash was investigated under controlled conditions. The reaction stages are identified with the initial moisture removal, volatilization, melting and slag formation. At the temperature higher than 1100 degrees C, the ESP ashes have a quicker weight loss, and the total weight loss reaches up to 52%, higher than the boiler ash. At 1400 degrees C a salt layer and a homogeneous glassy slag were formed. The effect of thermal treatment on the leaching characteristics of various elements in the ESP ash was evaluated with the availability-leaching test. The leaching values of the vitrified slag are significantly lowered than that of the original ash.

  2. Pattern transformations in periodic cellular solids under external stimuli

    Science.gov (United States)

    Zhang, K.; Zhao, X. W.; Duan, H. L.; Karihaloo, B. L.; Wang, J.

    2011-04-01

    The structural patterns of periodic cellular materials play an important role in their properties. Here, we investigate how these patterns transform dramatically under external stimuli in simple periodic cellular structures that include a nanotube bundle and a millimeter-size plastic straw bundle. Under gradual hydrostatic straining up to 20%, the cross-section of the single walled carbon nanotube bundle undergoes several pattern transformations, while an amazing new hexagram pattern is triggered from the circular shape when the strain of 20% is applied suddenly in one step. Similar to the nanotube bundle, the circular plastic straw bundle is transformed into a hexagonal pattern on heating by conduction through a baseplate but into a hexagram pattern when heated by convection. Besides the well-known elastic buckling, we find other mechanisms of pattern transformation at different scales; these include the minimization of the surface energy at the macroscale or of the van der Waals energy at the nanoscale and the competition between the elastic energy of deformation and either the surface energy at the macroscale or the van der Waals energy at the nanoscale. The studies of the pattern transformations of periodic porous materials offer new insights into the fabrication of novel materials and devices with tailored properties.

  3. Recoverable and Programmable Collapse from Folding Pressurized Origami Cellular Solids

    Science.gov (United States)

    Li, S.; Fang, H.; Wang, K. W.

    2016-09-01

    We report a unique collapse mechanism by exploiting the negative stiffness observed in the folding of an origami solid, which consists of pressurized cells made by stacking origami sheets. Such a collapse mechanism is recoverable, since it only involves rigid folding of the origami sheets and it is programmable by pressure control and the custom design of the crease pattern. The collapse mechanism features many attractive characteristics for applications such as energy absorption. The reported results also suggest a new branch of origami study focused on its nonlinear mechanics associated with folding.

  4. Experimental micro mechanics methods for conventional and negative Poisson's ratio cellular solids as Cosserat continua

    Science.gov (United States)

    Lakes, R.

    1991-01-01

    Continuum representations of micromechanical phenomena in structured materials are described, with emphasis on cellular solids. These phenomena are interpreted in light of Cosserat elasticity, a generalized continuum theory which admits degrees of freedom not present in classical elasticity. These are the rotation of points in the material, and a couple per unit area or couple stress. Experimental work in this area is reviewed, and other interpretation schemes are discussed. The applicability of Cosserat elasticity to cellular solids and fibrous composite materials is considered as is the application of related generalized continuum theories. New experimental results are presented for foam materials with negative Poisson's ratios.

  5. Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour.

    Science.gov (United States)

    Fokkelman, Michiel; Balcıoğlu, Hayri E; Klip, Janna E; Yan, Kuan; Verbeek, Fons J; Danen, Erik H J; van de Water, Bob

    2016-08-17

    Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour.

  6. Yielding and post-yield behaviour of closed-cell cellular materials under multiaxial dynamic loading

    Science.gov (United States)

    Vesenjak, Matej; Ren, Zoran

    2016-05-01

    The paper focuses on characterisation of yielding and post-yield behaviour of metals with closed-cell cellular structure when subjected to multiaxial dynamic loading, considering the influence of the relative density, base material, strain rate and pore gas pressure. Research was conducted by extensive parametric fully-coupled computational simulations using the finite element code LS-DYNA. Results have shown that the macroscopic yield stress of cellular material rises with increase of the relative density, while its dependence on the hydrostatic stress decreases. The yield limit also rises with increase of the strain rate, while the hydrostatic stress influence remains more or less the same at different strain-rates. The macroscopic yield limit of the cellular material is also strongly influenced by the choice of base material since the base materials with higher yield limit contribute also to higher macroscopic yield limit of the cellular material. By increasing the pore gas filler pressure the dependence on hydrostatic stress increases while at the same time the yield surface shifts along the hydrostatic axis in the negative direction. This means that yielding at compression is delayed due to influence of the initial pore pressure and occurs at higher compressive loading, while the opposite is true for tensile loading.

  7. Determination of the mechanical properties of solid and cellular polymeric dosage forms by diametral compression.

    Science.gov (United States)

    Blaesi, Aron H; Saka, Nannaji

    2016-07-25

    At present, the immediate-release solid dosage forms, such as the oral tablets and capsules, are granular solids. They release drug rapidly and have adequate mechanical properties, but their manufacture is fraught with difficulties inherent in processing particulate matter. Such difficulties, however, could be overcome by liquid-based processing. Therefore, we have recently introduced polymeric cellular (i.e., highly porous) dosage forms prepared from a melt process. Experiments have shown that upon immersion in a dissolution medium, the cellular dosage forms with polyethylene glycol (PEG) as excipient and with predominantly open-cell topology disintegrate by exfoliation, thus enabling rapid drug release. If the volume fraction of voids of the open-cell structures is too large, however, their mechanical strength is adversely affected. At present, the common method for determining the tensile strength of brittle, solid dosage forms (such as select granular forms) is the diametral compression test. In this study, the theory of diametral compression is first refined to demonstrate that the relevant mechanical properties of ductile and cellular solids (i.e., the elastic modulus and the yield strength) can also be extracted from this test. Diametral compression experiments are then conducted on PEG-based solid and cellular dosage forms. It is found that the elastic modulus and yield strength of the open-cell structures are about an order of magnitude smaller than those of the non-porous solids, but still are substantially greater than the stiffness and strength requirements for handling the dosage forms manually. This work thus demonstrates that melt-processed polymeric cellular dosage forms that release drug rapidly can be designed and manufactured to have adequate mechanical properties.

  8. An improved instrumental characterization of mechanical and acoustic properties of crispy cellular solid food

    NARCIS (Netherlands)

    Vliet, T. van; Castro-Prada, E.M.; Luyten, H.; Lichtendonk, W.; Hamer, R.J.

    2007-01-01

    A detailed study was performed to simultaneously measure the mechanical and acoustic properties of crispy cellular solid foods. Different critical aspects are discussed in order to assess optimal test conditions. These are primarily data sampling rate, microphone positioning, frequency spectrum of i

  9. Computational Modelling of the Structural Integrity following Mass-Loss in Polymeric Charred Cellular Solids

    Directory of Open Access Journals (Sweden)

    J. P. M. Whitty

    2014-01-01

    Full Text Available A novel computational technique is presented for embedding mass-loss due to burning into the ANSYS finite element modelling code. The approaches employ a range of computational modelling methods in order to provide more complete theoretical treatment of thermoelasticity absent from the literature for over six decades. Techniques are employed to evaluate structural integrity (namely, elastic moduli, Poisson’s ratios, and compressive brittle strength of honeycomb systems known to approximate three-dimensional cellular chars. That is, reducing the mass of diagonal ribs and both diagonal-plus-vertical ribs simultaneously show rapid decreases in the structural integrity of both conventional and reentrant (auxetic, i.e., possessing a negative Poisson’s ratio honeycombs. On the other hand, reducing only the vertical ribs shows initially modest reductions in such properties, followed by catastrophic failure of the material system. Calculations of thermal stress distributions indicate that in all cases the total stress is reduced in reentrant (auxetic cellular solids. This indicates that conventional cellular solids are expected to fail before their auxetic counterparts. Furthermore, both analytical and FE modelling predictions of the brittle crush strength of both auxteic and conventional cellular solids show a relationship with structural stiffness.

  10. An improved cellular automaton model considering the effect of traffic lights and driving behaviour

    Institute of Scientific and Technical Information of China (English)

    He Hong-Di; Lu Wei-Zhen; Dong Li-Yun

    2011-01-01

    This paper proposes an improved cellular automaton model to describe the urban traffic flow with the consideration of traffic light and driving behaviour effects. Based on the model, the characteristics of the urban traffic flow on a singlelane road are investigated under three different control strategies, i.e., the synchronized, the green wave and the random strategies. The fundamental diagrams and time-space patterns of the traffic flows are provided for these strategies respectively. It finds that the dynamical transition to the congested flow appears when the vehicle density is higher than a critical level. The saturated flow is less dependent on the cycle time and the strategies of the traffic light control,while the critical vehicle density varies with the cycle time and the strategies. Simulated results indicate that the green wave strategy is proven to be the most effective one among the above three control strategies.

  11. An improved cellular automaton model considering the effect of traffic lights and driving behaviour

    Science.gov (United States)

    He, Hong-Di; Lu, Wei-Zhen; Dong, Li-Yun

    2011-04-01

    This paper proposes an improved cellular automaton model to describe the urban traffic flow with the consideration of traffic light and driving behaviour effects. Based on the model, the characteristics of the urban traffic flow on a single-lane road are investigated under three different control strategies, i.e., the synchronized, the green wave and the random strategies. The fundamental diagrams and time-space patterns of the traffic flows are provided for these strategies respectively. It finds that the dynamical transition to the congested flow appears when the vehicle density is higher than a critical level. The saturated flow is less dependent on the cycle time and the strategies of the traffic light control, while the critical vehicle density varies with the cycle time and the strategies. Simulated results indicate that the green wave strategy is proven to be the most effective one among the above three control strategies.

  12. Rheological behaviour of semi-solid succinonitrile-camphor alloy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Rheology experiments were carried out on succinonitrile-4% (mass fraction) camphor alloy, using a Haake VT550 viscometer.The results showed that the steady state viscosity of succinonitrile-4% camphor alloy in semi-solid process can be described well by the classical power law of viscosity versus shear rate, η= kym, and the test method can be used to simulate the semi-solid processing for metals. The viscosity of the organic alloy decreases with increasing shear rate at a given temperature within liquid-solid range, and the viscosity of the organic alloy slurries increases with decreasing temperature, decreases with decreasing cooling rate. The structure and viscosity of organic alloy during solidification are strongly influenced by shear rate.

  13. Social interactions of eating behaviour among high school students: a cellular automata approach.

    Science.gov (United States)

    Dabbaghian, Vahid; Mago, Vijay K; Wu, Tiankuang; Fritz, Charles; Alimadad, Azadeh

    2012-10-09

    Overweight and obesity in children and adolescents is a global epidemic posing problems for both developed and developing nations. The prevalence is particularly alarming in developed nations, such as the United States, where approximately one in three school-aged adolescents (ages 12-19) are overweight or obese. Evidence suggests that weight gain in school-aged adolescents is related to energy imbalance exacerbated by the negative aspects of the school food environment, such as presence of unhealthy food choices. While a well-established connection exists between the food environment, presently there is a lack of studies investigating the impact of the social environment and associated interactions of school-age adolescents. This paper uses a mathematical modelling approach to explore how social interactions among high school adolescents can affect their eating behaviour and food choice. In this paper we use a Cellular Automata (CA) modelling approach to explore how social interactions among school-age adolescents can affect eating behaviour, and food choice. Our CA model integrates social influences and transition rules to simulate the way individuals would interact in a social community (e.g., school cafeteria). To replicate these social interactions, we chose the Moore neighbourhood which allows all neighbours (eights cells in a two-dimensional square lattice) to influence the central cell. Our assumption is that individuals belong to any of four states; Bring Healthy, Bring Unhealthy, Purchase Healthy, and Purchase Unhealthy, and will influence each other according to parameter settings and transition rules. Simulations were run to explore how the different states interact under varying parameter settings. This study, through simulations, illustrates that students will change their eating behaviour from unhealthy to healthy as a result of positive social and environmental influences. In general, there is one common characteristic of changes across time

  14. Thermal treatment of solid waste in view of recycling: Chromate and molybdate formation and leaching behaviour.

    Science.gov (United States)

    Verbinnen, Bram; Billen, Pieter; Vandecasteele, Carlo

    2014-06-01

    Elevated Cr and Mo concentrations are often found in leachates of thermally treated solid waste, but there is no general explanation for this so far. Therefore, we studied the leaching behaviour after thermal treatment as a function of heating temperature and residence time for two types of solid waste: contaminated sludge and bottom ash from municipal solid waste incineration. The leaching behaviour of both waste streams was compared with experiments on synthetic samples, allowing deduction of a general mechanism for Cr and Mo leaching. Cr and Mo showed a similar leaching behaviour: after an initial increase, the leaching decreased again at higher temperatures. Oxidation of these elements from their lower oxidation states to chromate and molybdate at temperatures up to 600 °C was responsible for the increased leaching. At higher temperatures, both Mo and Cr leaching decreased again owing to the formation of an amorphous phase, incorporating the newly formed chromate and molybdate salts, which prevents them from leaching.

  15. Public concerns and behaviours towards solid waste management in Italy.

    Science.gov (United States)

    Sessa, Alessandra; Di Giuseppe, Gabriella; Marinelli, Paolo; Angelillo, Italo F

    2010-12-01

    A self-administered questionnaire investigated knowledge, perceptions of the risks to health associated with solid waste management, and practices about waste management in a random sample of 1181 adults in Italy. Perceived risk of developing cancer due to solid waste burning was significantly higher in females, younger, with an educational level lower than university and who believed that improper waste management is linked to cancer. Respondents who had visited a physician at least once in the last year for fear of contracting a disease due to the non-correct waste management had an educational level lower than university, have modified dietary habits for fear of contracting disease due to improper waste management, believe that improper waste management is linked to allergies, perceive a higher risk of contracting infectious disease due to improper waste management and have participated in education/information activities on waste management. Those who more frequently perform with regularity differentiate household waste collection had a university educational level, perceived a higher risk of developing cancer due to solid waste burning, had received information about waste collection and did not need information about waste management. Educational programmes are needed to modify public concern about adverse health effects of domestic waste.

  16. Viscoelastic Behaviour of Solid Propellants based on Various Polymeric Binders

    Directory of Open Access Journals (Sweden)

    N. Prabhakaran

    1995-01-01

    Full Text Available The dynamic mechanical properties of different binders and corresponding propellants are studied in terms of storage modulus and loss tangent. The binders investigated are HTPB, CTPB, PBAN, HEF-20 and ISRO polyol. The viscoelastic behaviour is investigated using Rheovibron viscoelastometer at 35 Hz covering a wide temperature range (-100 degree centigrade to 100 degree centigrade. The properties of the binder and corresponding propellant are compared in terms of parameters, tan delta/sub max/, T/sub g/ and the trend of their master relaxation modulus curves. It is found that polybutadiene binders exhibit lowest T/sub g/ (around -60 degree centigrade and ISRO polyol the highest (near -20 degree centigrade. The propellants have higher moduli than the binders at any temperature. The master relaxation modulus curve is influenced by the type of propellant.

  17. Hydrodynamic behaviour of a gas—solid counter-current packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; Swaaij, van W.P.M.

    1979-01-01

    Trickle flow of a more or less fluidized catalyst through a packed column is a promising new gas—solid counter-current operation. The hydrodynamic, behaviour of such a column, filled with dumped PALL rings, has been investigated, while some results have been obtained with RASCHIG rings and cylindric

  18. Agglomeration and Deposition Behaviour of Solid Recovered Fuel

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Jensen, Peter Arendt; Hjuler, Klaus;

    2016-01-01

    Waste-derived fuels, such as solid recovered fuel (SRF), are increasingly being used in, e.g., the cement industry as a means to reduce cost. The inhomogeneous nature of SRF makes it difficult to combust, and many problems may arise within, e.g., combustion control, feeding of fuel, deposit...... formation, or accumulation of impurities. The combustion of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), wood, and SRF were studied in a rotary drum furnace. The combustion was recorded on a camera (60 frames per second), so that any agglomeration or deposition of fuel or ash...... could be monitored. PE and PP pose no significant risk of forming deposits in a combustion environment (T > 800 °C) as a result of a rapid devolatilization, while PET may cause deposits as a result of a sticky char residue. The deposition tendency of the investigated SRF is low, and it may be managed...

  19. Efficient cellular solid-state NMR of membrane proteins by targeted protein labeling

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Lindsay A. [University of Oxford, Oxford Particle Imaging Centre, The Wellcome Trust Centre for Human Genetics, Division of Structural Biology, Nuffield Department of Medicine (United Kingdom); Daniëls, Mark; Cruijsen, Elwin A. W. van der; Folkers, Gert E.; Baldus, Marc, E-mail: m.baldus@uu.nl [Utrecht University, NMR Spectroscopy, Department of Chemistry, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands)

    2015-06-15

    Solid-state NMR spectroscopy (ssNMR) has made significant progress towards the study of membrane proteins in their native cellular membranes. However, reduced spectroscopic sensitivity and high background signal levels can complicate these experiments. Here, we describe a method for ssNMR to specifically label a single protein by repressing endogenous protein expression with rifampicin. Our results demonstrate that treatment of E. coli with rifampicin during induction of recombinant membrane protein expression reduces background signals for different expression levels and improves sensitivity in cellular membrane samples. Further, the method reduces the amount of time and resources needed to produce membrane protein samples, enabling new strategies for studying challenging membrane proteins by ssNMR.

  20. The spreading behaviour of perfluoropolyether droplets on solid surfaces

    Institute of Scientific and Technical Information of China (English)

    Guo Xiao-Yan; Li Xin; Hu Yuan-Zhong; Wang Hui

    2008-01-01

    The spread of perfluoropolyether (PFPE) droplets on solid surfaces has been measured from the top-down view through a microscope system. Effects of substrates, molecular weight and end-group functionality on spreading of the PFPE droplets have been studied experimentally and the results were compared with those by molecular dynamics (MD)simulations. Silicon wafer and diamond-like carbon (DLC) substrates were used to study the effect of substrates on spreading. Two types of PFPE, Z-dol and Z-tetraol, with the same chain structure and various molecular weights (2000 and 4000 g/mol) were employed in experiments. Effect of molecular weight has been investigated through comparing the spreading of Z-dol 2000 and Z-dol 4000, and it is found that the increase of molecular weight will decrease the mobility of PFPE. Comparison between spreading of Z-dol and Z-tetraol of the same molecular weight proved that functional end group plays a significant role on the spreading of PFPE, which confirmed the MD simulation results.

  1. Cuttlebone-like V2O5 Nanofibre Scaffolds – Advances in Structuring Cellular Solids

    Science.gov (United States)

    Knöller, Andrea; Runčevski, Tomče; Dinnebier, Robert E.; Bill, Joachim; Burghard, Zaklina

    2017-02-01

    The synthesis of ceramic materials combining high porosity and permeability with good mechanical stability is challenging, as optimising the latter requires compromises regarding the first two properties. Nonetheless, significant progress can be made in this direction by taking advantage of the structural design principles evolved by nature. Natural cellular solids achieve good mechanical stability via a defined hierarchical organisation of the building blocks they are composed of. Here, we report the first synthetic, ceramic-based scaffold whose architecture closely mimics that of cuttlebone –a structural biomaterial whose porosity exceeds that of most other natural cellular solids, whilst preserving an excellent mechanical strength. The nanostructured, single-component scaffold, obtained by ice-templated assembly of V2O5 nanofibres, features a highly sophisticated and elaborate architecture of equally spaced lamellas, which are regularly connected by pillars as lamella support. It displays an unprecedented porosity of 99.8 %, complemented by an enhanced mechanical stability. This novel bioinspired, functional material not only displays mechanical characteristics similar to natural cuttlebone, but the multifunctionality of the V2O5 nanofibres also renders possible applications, including catalysts, sensors and electrodes for energy storage.

  2. Quality Dimensions, Value, Service Cost and Recommendation Behaviour: Evidence from the Nigerian Cellular Industry

    OpenAIRE

    Abolaji Joachim Abiodun; Kenneth Sola Adeyemi; Adewale Omotayo Osibanjo

    2014-01-01

    The present study proposed and test a model that connects both affective and cognitive factors in cellular service to customers’ recommendation behavior. Results of the analysis of data collected through questionnaire from 293 respondents with cellular phones and active account in the Nigerian cellular industry indicate that core cellular service dimensions, service cost (price) and hedonic values are significant determinants of customers’ recommendation behavior. In addition, the study found...

  3. Effect of surface chemistry on the behaviour of solid particles in multiphase flow

    Energy Technology Data Exchange (ETDEWEB)

    Gulbrandsen, Egil; Pedersen, Anette

    2006-03-15

    The surface chemical properties of solids particles strongly influence their behaviour in multiphase flow, e.g. their tendency to be transported by the oil or water phase, their tendency to stick to the oil-water interfaces, or their tendency to aggregate. The behaviour of the solid particles may influence various processes such as emulsion breakdown, oil-water separation, or sedimentation of solids in a pipeline, and thereby issues as erosion, and corrosion under deposits. These issues were addressed in the present laboratory study. The reported results focus on behaviour of sand in a simple oil-water system in presence of a model corrosion inhibitor compound, cetyltrimethylammonium bromide. A refined oil was used in the tests. The system was studied by various methods like zeta-potential measurements, assessment of wetting properties and tendency of aggregation and sedimentation in oil-water system. It was found that surface-active corrosion inhibitor could strongly influence the wetting of the sand. By addition of the corrosion inhibitor, the sand changed from water wet to oil wet. This change induced a tendency to aggregation of the sand grains. The aggregation led to sticky deposits of sand. This may have an impact on under deposit corrosion phenomena. (Author)

  4. Characterization of cellular solids in Ti6Al4V for orthopaedic implant applications: Trabecular titanium.

    Science.gov (United States)

    Marin, E; Fusi, S; Pressacco, M; Paussa, L; Fedrizzi, L

    2010-07-01

    EBM (Electron Beam Melting) technology can be used successfully to obtain cellular solids in metallic biomaterials that can greatly increase osseointegration in arthroprothesis and at the same time maintain good mechanical properties. The investigated structures, called Trabecular Titanium, usually cannot be obtained by traditional machining. Two samples: (A) with a smaller single cell area and, (B) with a bigger single cell area, were produced and studied in this project. They have been completely characterized and compared with the results in similar literature pertinent to Ti6Al4V EBM structures. Relative density was evaluated using different methods, the mean diameter of the open porosities was calculated by Scanning Electron Microscope images; the composition was evaluated using Energy-Dispersive X-Ray Spectroscopy; the microstructure (alpha-beta) was investigated using chemical etching and, the mechanical proprieties were investigated using UMTS. The mean porosity values resulted comparable with spongy bone (63% for A and 72% for B). The mean diameter of the single porosity (650 mum for A and 1400 mum for B) resulted compatible with the osseointegration data from the literature, in particular for sample A. The Vickers micro-hardness tests and the chemical etching demonstrated that the structure is fine, uniform and well distributed. The mechanical test proved that sample (A) was more resistant than sample (B), but sample (B) showed an elastic modulus almost equal to the value of spongy bone. The results of this study suggest that the two Ti6Al4V cellular solids can be used in biomedical applications to promote osseointegration demonstrating that they maybe successfully used in prosthetic implants. Additional implant results will be published in the near future. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. A hybrid cellular automaton model of solid tumor growth and bioreductive drug transport.

    Science.gov (United States)

    Kazmi, Nabila; Hossain, M A; Phillips, Roger M

    2012-01-01

    Bioreductive drugs are a class of hypoxia selective drugs that are designed to eradicate the hypoxic fraction of solid tumors. Their activity depends upon a number of biological and pharmacological factors and we used a mathematical modeling approach to explore the dynamics of tumor growth, infusion, and penetration of the bioreductive drug Tirapazamine (TPZ). An in-silico model is implemented to calculate the tumor mass considering oxygen and glucose as key microenvironmental parameters. The next stage of the model integrated extra cellular matrix (ECM), cell-cell adhesion, and cell movement parameters as growth constraints. The tumor microenvironments strongly influenced tumor morphology and growth rates. Once the growth model was established, a hybrid model was developed to study drug dynamics inside the hypoxic regions of tumors. The model used 10, 50 and 100 \\mu {\\rm M} as TPZ initial concentrations and determined TPZ pharmacokinetic (PK) (transport) and pharmacodynamics (cytotoxicity) properties inside hypoxic regions of solid tumor. The model results showed that diminished drug transport is a reason for TPZ failure and recommend the optimization of the drug transport properties in the emerging TPZ generations. The modeling approach used in this study is novel and can be a step to explore the behavioral dynamics of TPZ.

  6. Quality Dimensions, Value, Service Cost and Recommendation Behaviour: Evidence from the Nigerian Cellular Industry

    Directory of Open Access Journals (Sweden)

    Abolaji Joachim Abiodun

    2014-09-01

    Full Text Available The present study proposed and test a model that connects both affective and cognitive factors in cellular service to customers’ recommendation behavior. Results of the analysis of data collected through questionnaire from 293 respondents with cellular phones and active account in the Nigerian cellular industry indicate that core cellular service dimensions, service cost (price and hedonic values are significant determinants of customers’ recommendation behavior. In addition, the study found that customer service and utilitarian value exert negative effect on recommendation behavior. It seems that strengthening the performance of service providers on core service attributes, service cost (price and the entertainment and emotion evoking aspects of cellular service is of more value in partnering with customer to enlarge customer base through recommendation

  7. Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Ji P

    2016-03-01

    Full Text Available Peng Ji, Tong Yu, Ying Liu, Jie Jiang, Jie Xu, Ying Zhao, Yanna Hao, Yang Qiu, Wenming Zhao, Chao WuCollege of Pharmacy, Liaoning Medical University, Jinzhou, Liaoning Province, People’s Republic of ChinaAbstract: Naringenin (NRG, a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only ~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle

  8. Transient demonstration of exciton behaviours in solid state cathodoluminescence under different driving voltage

    Institute of Scientific and Technical Information of China (English)

    Zhang Fu-Jun; Zhao Su-Ling; Xu Zheng; Huang Jin-Zhao; Xu Xu-Rong

    2007-01-01

    In the solid state cathodoluminescence (SSCL), organic materials were excited by hot electrons accelerated in silicon oxide (SiO2) layer under alternating current (AC). In this paper exciton behaviours were analysed by using transient spectra under different driving voltages. The threshold voltages of SSCL and exciton ionization were obtained from the transient spectra. The recombination radiation occurred when the driving voltage went beyond the threshold voltage of exciton ionization. Prom the transient spectrum of two kinds of luminescence (exciton emission and recombination radiation), it was demonstrated that recombination radiation should benefit from the exciton ionization.

  9. Transient behaviour of deposition of liquid metal droplets on a solid substrate

    Science.gov (United States)

    Chapuis, J.; Romero, E.; Soulié, F.; Bordreuil, C.; Fras, G.

    2016-10-01

    This paper investigates the mechanisms that contribute to the spreading of liquid metal macro-drop deposited during Stationary Pulsed Gas Metal Arc Welding on an initially cold solid workpiece. Surface tension and inertial effects take an important part in the behaviour of the liquid metal macro-drop, but in this configuration the influence of energetic effects can also be significant. The experimental results are discussed in the light of dimensional analysis in order to appreciate the influence of the process parameters and the physical mechanisms involved on the spreading of a macro-drop. A law is established to model forced non-isothermal spreading.

  10. Pyrolysis and combustion behaviour of wood: temperature profiles and solid conversion

    Energy Technology Data Exchange (ETDEWEB)

    Ceamanos, J.; Bilbao, R.; Aldea, M.E.; Betran, M.; Mastral, J.F. [University of Zaragoza (Spain)

    1999-07-01

    The development of techniques for the production of electricity by pyrolysis and combustion of biomass must take into account the behaviour of large particles under very different experimental conditions. In this work the influences of the variable heat flux, the moisture content of the sample and the atmosphere surrounding the particle have been studied. The mathematical model developed takes into account variable thermal properties, variation of temperature and enthalpy of water vaporization with water content, and thermal decomposition kinetics previously obtained by thermogravimetry. It predicts temperature and moisture profiles inside the solid as well as the global conversion. The results obtained agree with the experimental results for most conditions. (author)

  11. Extra-cellular isoamylase production by Rhizopus oryzae in solid-state fermentation of agro wastes

    Directory of Open Access Journals (Sweden)

    Barnita Ghosh

    2011-10-01

    Full Text Available Extra-cellular isoamylase was produced by Rhizopus oryzae PR7 in solid-state fermentations of various agro wastes, among which millet, oat, tapioca, and arum (Colocasia esculenta showed promising results. The highest amount of enzyme production was obtained after 72 h of growth at 28°C. The optimum pH for enzyme production was - 8.0. Among the various additives tested, enzyme production increased with ions such as Ca2+, Mg2+ and also with cysteine, GSH, and DTT. The enzyme synthesis was reduced in the presence of thiol inhibitors like Cu2+ and pCMB. The surfactants like Tween-40, Tween-80 and Triton X-100 helped in enhancing the enzyme activity. The production could be further increased by using the combinations of substrates. The ability to produce high amount of isoamylase within a relatively very short period and the capability of degrading wastes could make the strain suitable for commercial production of the enzyme.

  12. The contact line behaviour of solid-liquid-gas diffuse-interface models

    CERN Document Server

    Sibley, David N; Savva, Nikos; Kalliadasis, Serafim

    2013-01-01

    A solid-liquid-gas moving contact line is considered through a diffuse-interface model with the classical boundary condition of no-slip at the solid surface. Examination of the asymptotic behaviour as the contact line is approached shows that the relaxation of the classical model of a sharp liquid-gas interface, whilst retaining the no-slip condition, resolves the stress and pressure singularities associated with the moving contact line problem while the fluid velocity is well defined (not multi-valued). The moving contact line behaviour is analysed for a general problem relevant for any density dependent dynamic viscosity and volume viscosity, and for general microscopic contact angle and double well free-energy forms. Away from the contact line, analysis of the diffuse-interface model shows that the Navier--Stokes equations and classical interfacial boundary conditions are obtained at leading order in the sharp-interface limit, justifying the creeping flow problem imposed in an intermediate region in the se...

  13. Naringenin-loaded solid lipid nanoparticles: preparation, controlled delivery, cellular uptake, and pulmonary pharmacokinetics.

    Science.gov (United States)

    Ji, Peng; Yu, Tong; Liu, Ying; Jiang, Jie; Xu, Jie; Zhao, Ying; Hao, Yanna; Qiu, Yang; Zhao, Wenming; Wu, Chao

    2016-01-01

    Naringenin (NRG), a flavonoid compound, had been reported to exhibit extensive pharmacological effects, but its water solubility and oral bioavailability are only~46±6 µg/mL and 5.8%, respectively. The purpose of this study is to design and develop NRG-loaded solid lipid nanoparticles (NRG-SLNs) to provide prolonged and sustained drug release, with improved stability, involving nontoxic nanocarriers, and increase the bioavailability by means of pulmonary administration. Initially, a group contribution method was used to screen the best solid lipid matrix for the preparation of SLNs. NRG-SLNs were prepared by an emulsification and low-temperature solidification method and optimized using an orthogonal experiment approach. The morphology was examined by transmission electron microscopy, and the particle size and zeta potential were determined by photon correlation spectroscopy. The total drug content of NRG-SLNs was measured by high-performance liquid chromatography, and the encapsulation efficiency (EE) was determined by Sephadex gel-50 chromatography and high-performance liquid chromatography. The in vitro NRG release studies were carried out using a dialysis bag. The best cryoprotectant to prepare NRG-SLN lyophilized powder for future structural characterization was selected using differential scanning calorimetry, powder X-ray diffraction, and Fourier transform infrared spectroscopy. The short-term stability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay, cellular uptake, and pharmacokinetics in rats were studied after pulmonary administration of NRG-SLN lyophilized powder. Glycerol monostearate was selected to prepare SLNs, and the optimal formulation of NRG-SLNs was spherical in shape, with a particle size of 98 nm, a polydispersity index of 0.258, a zeta potential of -31.4 mV, a total drug content of 9.76 mg, an EE of 79.11%, and a cumulative drug release of 80% in 48 hours with a sustained profile. In addition, 5% mannitol (w

  14. The influence of dipalmitoyl phosphatidylserine on phase behaviour of and cellular response to lyotropic liquid crystalline dispersions.

    Science.gov (United States)

    Shen, Hsin-Hui; Crowston, Jonathan G; Huber, Florian; Saubern, Simon; McLean, Keith M; Hartley, Patrick G

    2010-12-01

    Lyotropic liquid crystalline nanoparticles (cubosomes) have the potential to act as amphiphilic scaffolds for the presentation of lipids and subsequent application in, for example, bioseparations and therapeutic delivery. In this work we have formulated lyotropic liquid crystalline systems based on the synthetic amphiphile 1,2,3-trihydroxy-3,7,11,15-tetramethylhexadecane (phytantriol) and containing the lipid dipalmitoyl phosphatidylserine (DPPS). We have prepared a range of DPPS-containing phytantriol cubosome formulations and characterized them using Small Angle X-ray Scattering and Cryo-transmission electron microscopy. These techniques show that increased DPPS content induces marked changes in lyotropic liquid crystalline phase behaviour, characterized by changes in crystallographic dimensions and increases in vesicle content. Furthermore, in vitro cell culture studies indicate that these changes correlate with lipid/surfactant cellular uptake and cytotoxicity. A model cell membrane based on a surface supported phospholipid bilayer was used to gain insights into cubosome-bilayer interactions using Quartz Crystal Microgravimetry. The data show that mass uptake at the supported bilayer increased with DPPS content. We propose that the cytotoxicity of the DPPS-containing dispersions results from changes in lipid/surfactant phase behaviour and the preferential attachment and fusion of vesicles at the cell membrane.

  15. Hygromorphic behaviour of cellular material: hysteretic swelling and shrinkage of wood probed by phase contrast X-ray tomography

    Science.gov (United States)

    Derome, Dominique; Rafsanjani, Ahmad; Patera, Alessandra; Guyer, Robert; Carmeliet, Jan

    2012-10-01

    Wood is a hygromorphic material, meaning it responds to changes in environmental humidity by changing its geometry. Its cellular biological structure swells during wetting and shrinks during drying. The origin of the moisture-induced deformation lies at the sub-cellular scale. The cell wall can be considered a composite material with stiff cellulose fibrils acting as reinforcement embedded in a hemicellulose/lignin matrix. The bulk of the cellulose fibrils, forming 50% of the cell wall, are oriented longitudinally, forming long-pitched helices. Both components of cell wall matrix are displaying swelling. Moisture sorption and, to a lesser degree, swelling/shrinkage are known to be hysteretic. We quantify the affine strains during the swelling and shrinkage using high resolution images obtained by phase contrast synchrotron X-ray tomography of wood samples of different porosities. The reversibility of the swelling/shrinkage is found for samples with controlled moisture sorption history. The deformation is more hysteretic for high than for low density samples. Swelling/shrinkage due to ad/desorption of water vapour displays also a non-affine component. The reversibility of the swelling/shrinkage indicates that the material has a structural capacity to show a persistent cellular geometry for a given moisture state and a structural composition that allows for moisture-induced transitional states. A collection of qualitative observations of small subsets of cells during swelling/shrinkage is further studied by simulating the observed behaviour. An anisotropic swelling coefficient of the cell wall is found to emerge and its origin is linked to the anisotropy of the cellulose fibrils arrangement in cell wall layers.

  16. Researches on the behaviour of cellular antiballistic composites based on AlMg-SiC alloys

    Science.gov (United States)

    Bălţătescu, O.; Florea, R. M.; Rusu, I.; Carcea, I.

    2015-11-01

    The researches presented in this paper refers basically to the impact of a small/medium caliber bullet shot on a light armor built on the base of a AlMg-SiC metallic composite cellular/foam. Thus, we study the antiballistic behavior and protection properties of the armor, based on the effects that occur at the impact zone of the bullet with the composite surface. We performed an antiballistic behavior modeling by means of a finite element analysis, based on a "multi grid" Fast Finite Element (FFE) system. We used for this purpose the DYNA 2D software package. The obtained samples show after the impact the occurrence of concentration / deformation pores effect and intercellular cracks development to the interior of the composite. Those effects, depending on speed, mass and length of the projectile ballistic trajectory, reduce zonal tensions due to the effect of cell walls deformation. It was obtained a good correlation between modeling results and the electron microscope analyse of the impact area. It is worth mentioning that almost all values for impact energy absorbed by the composite armor are in the protection active zone provided by it.

  17. Adaptive responses and cellular behaviour of biphenyl-degrading bacteria toward polychlorinated biphenyls.

    Science.gov (United States)

    Chávez, Francisco P; Gordillo, Felipe; Jerez, Carlos A

    2006-01-01

    Polychlorinated biphenyls (PCBs) are one of the most widely distributed classes of chlorinated chemicals in the environment. For cleanup of large areas of PCB-contaminated environments, bioremediation seems to be a promising approach. However, the multitude of PCB congeners, their low bioavailability and high toxicity are important factors that affect the cleanup progression. Elucidating how the PCB-degrading microorganisms involved in the process adapt to and deal with the stressing conditions caused by this class of compounds may help to improve the bioremediation process. Also specific physiological characteristics of biphenyl-utilizing bacteria involved in the degradation of PCBs may enhance their availability to these compounds and therefore contribute to a better microbial mineralization. This review will focus in the stress responses caused in aerobic biphenyl-utilizing bacteria by PCBs and its metabolic intermediates and will also analyze bacterial properties such as motility and chemotaxis, adherence to solid surfaces, biosurfactant production and biofilm development, all properties found to enhance bacteria-pollutant interaction.

  18. Cellular uptake and degradation behaviour of biodegradable poly(ethylene glycol-graft-methyl methacrylate) nanoparticles crosslinked with dimethacryloyl hydroxylamine.

    Science.gov (United States)

    Scheler, Stefan; Kitzan, Martina; Fahr, Alfred

    2011-01-17

    Crosslinked polymers with hydrolytically cleavable linkages are highly interesting materials for the design of biodegradable drug carriers. The aim of this study was to investigate if nanoparticles made of such polymers have the potential to be used also for intracellular drug delivery. PEGylated nanoparticles were prepared by copolymerization of methacrylic acid esters and N,O-dimethacryloylhydroxylamine (DMHA). The particles were stable at pH 5.0. At pH 7.4 and 9.0 the degradation covered a time span of about 14 days, following first-order kinetics with higher crosslinked particles degrading slower. Cellular particle uptake and cytotoxicity were tested with L929 mouse fibroblasts. The particle uptake rate was found to correlate linearly with the surface charge and to increase as the zeta potential becomes less negative. Coating of the particle surface with polysorbate 80 drops the internalization rate close to zero and the charge dependence disappears. This indicates the existence of a second effect apart from surface charge. A similar pattern of correlation with zeta potential and coating was also found for the degree of membrane damage while there was no effect of polysorbate on the cell metabolism which increased as the negative charge decreased. It is discussed whether exocytotic processes may explain this behaviour.

  19. Impact of health education on community knowledge, attitudes and behaviour towards solid waste management in Al Ghobeiry, Beirut.

    Science.gov (United States)

    Karout, N; Altuwaijri, S

    2012-07-01

    The risks posed by accumulation of solid waste are most obvious in developing countries, where waste collection and treatment is often inadequate. This study aimed to determine the impact of a health education intervention (based on lectures and focus group discussions) on community knowledge, attitudes and behaviours concerning solid waste management in Al Ghobeiry, Beirut. A randomly selected sample of 320 inhabitants were divide into intervention and control groups who completed the same questionnaire in the pre- and post-intervention phases. Compared with the control group the intervention group, who attended the health education sessions, showed: significantly better knowledge about the problems of and diseases spread by accumulation of solid waste; better attitudes to management of solid waste collection; and improved practices in terms of handling and recycling of household waste. There was an observed increased participation by people in cleaning campaigns and voluntary work in all the municipality activities.

  20. Cellular solid-state NMR on large prokaryotic and eukaryotic membrane protein complexes

    NARCIS (Netherlands)

    Kaplan, M.

    2015-01-01

    Unraveling the structure and dynamics of biomolecules is pivotal to understand their function. Hitherto, structural biology has been dependent on data obtained under in-vitro circumstances thereby neglecting the influence of the natural environment. Here, we developed a solid-state Nuclear Magnetic

  1. Cellular solid-state NMR on large prokaryotic and eukaryotic membrane protein complexes

    NARCIS (Netherlands)

    Kaplan, M.

    2015-01-01

    Unraveling the structure and dynamics of biomolecules is pivotal to understand their function. Hitherto, structural biology has been dependent on data obtained under in-vitro circumstances thereby neglecting the influence of the natural environment. Here, we developed a solid-state Nuclear Magnetic

  2. Effect of glucosamine HCl on dissolution and solid state behaviours of piroxicam upon milling.

    Science.gov (United States)

    Al-Hamidi, Hiba; Edwards, Alison A; Douroumis, Dionysis; Asare-Addo, Kofi; Nayebi, Alireza Mohajjel; Reyhani-Rad, Siamak; Mahmoudi, Javad; Nokhodchi, Ali

    2013-03-01

    Piroxicam is a non-steroidal anti-inflammatory drug that is characterised by low solubility and high permeability. In order to improve the drug dissolution rate, the co-grinding method was used as an approach to prepare piroxicam co-ground in the carriers such as glucosamine hydrochloride. As, this amino sugar (glucosamine HCl) has been shown to decrease pain and improve mobility in osteoarthritis in joints, therefore, the incorporation of glucosamine in piroxicam formulations would be expected to offer additional benefits to patients. The effect of the order of grinding on the dissolution of piroxicam was also investigated. Co-ground drug and glucosamine were prepared in different ratios using a ball mill. The samples were then subjected to different grinding times. In order to investigate the effect of the grinding process on the dissolution behaviour of piroxicam, the drug was ground separately in the absence of glucosamine. Mixtures of ground piroxicam and unground D-glucosamine HCl were prepared. Physical mixtures of piroxicam and glucosamine were also prepared for comparison. The properties of prepared co-ground systems and physical mixtures were studied using a dissolution tester, FTIR, SEM, XRPD and DSC. These results showed that the presence of glucosamine HCl can increase dissolution rate of piroxicam compared to pure piroxicam. Generally, all dissolution profiles showed the fastest dissolution rate when ground piroxicam was mixed with unground glucosamine. This was closely followed by the co-grinding of piroxicam with glucosamine where lower grinding times showed the fastest dissolution. The solid state studies showed that the grinding of piroxicam for longer times had no effect on polymorphic form of piroxicam, whereas mixtures of piroxicam-glucosamine ground for longer times (60 min) converted piroxicam polymorph II to polymorph I.

  3. Ferroelectric behaviour in solid croconic acid using neutron scattering and first-principles density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, S., E-mail: sanghamitra.mukhopadhyay@stfc.ac.uk [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Gutmann, M.J.; Jura, M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Jochym, D.B. [Scientific Computing Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Jimenez-Ruiz, M. [Institut Laue Langevin, 6 rue Jules Horowitz 38042, Grenoble Cedex 9 (France); Sturniolo, S.; Refson, K. [Scientific Computing Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fernandez-Alonso, F. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2013-12-12

    Highlights: • We have presented results of neutron diffraction on croconic acid (CA). • We have presented results of inelastic neutron scattering (INS) spectra. • INS is compared with lattice dynamical simulations using density functional theory. • The prominent doublet in INS spectra around 1000 cm{sup −1} are from two hydrogen ions. • We identify the role of these H ions in the ferroelectricity of the CA crystal. - Abstract: A combination of neutron-scattering experiments and first-principles calculations using density-functional theory have been performed to explore the structural and dynamical properties of the single-component organic ferroelectric croconic acid. Neutron diffraction and spectroscopy have been used to determine the location and underlying vibrational motions of the hydrogen ions within the crystalline lattice, respectively. On the computational front we find that dispersion corrections within the generalised-gradient approximation are essential to obtain a satisfactory crystal structure for this organic solid. Two distinct types of hydrogen ions in the crystal also have been identified, located at the ‘hinge’ and ‘terrace’ positions of a pleated, accordion-like structure. Phonon calculations and simulated neutron spectra show that the prominent doublet observed at ca. 1000 cm{sup −1} arises from out-of-plane motions associated with these two types of hydrogen ions. Calculated Born-effective-charge tensors yield an anomalously high dynamic charge centered on the hydrogen ions at the hinges, a finding which serves to identify the primary motif underpinning ferroelectric behaviour in this novel material.

  4. Comprehensive finite element modeling of Ti-6Al-4V cellular solids fabricated by electron beam melting

    Science.gov (United States)

    Arrieta, Edel

    Additive manufacturing permits the fabrication of cellular metals which are materials that can be highly customizable and possess multiple and extraordinary properties such as damage tolerance, metamorphic and auxetic behaviors, and high specific stiffness. This makes them the subject of interest for innovative applications. With interest in these materials for energy absorption applications, this work presents the development of nonlinear finite element models in commercial software platforms (MSC Patran/Nastran) that permit the analysis of the deformation mechanisms of these materials under compressive loads. In the development of these models, a detailed multiscale study on the different factors affecting the response of cellular metals was conducted with the objective to understanding the physics with the objective of selecting the most appropriate experiments. In that manner, a series of experiments were conducted on Ti-6Al-4V specimens fabricated by electron beam melting at different manufacturing orientations. Digital image correlation was presented as a vital tool for the measurement of strains in specimens with complex shapes; the experiments contemplated compression and tension tests of Ti-6Al-4V solid components, as well as compression tests on cellular lattices of the same alloy. FEMs were developed from the same CAD file utilized for the fabrication of the lattices; in addition, different meshing approaches and mesh convergence analysis were discussed. The mesh density showed convergence in models with over 70,000 elements, permitting the evaluation of the stress/strain-distribution mechanisms in the lattices. However, because of the considerable variability of the experimental material properties, some numerical results showed significant errors in predicting the compressive force applied to the lattices during the experiments; thus suggesting the need to improve the quality control in the manufacturing process and develop better technologies in

  5. Anomalous dissolution behaviour of tablets prepared from sugar glass-based solid dispersions

    NARCIS (Netherlands)

    Van Drooge, D.J.; Hinrichs, W.L.J.; Frijlink, H.W.

    2004-01-01

    In this study, anomalous dissolution behaviour of tablets consisting of sugar glass dispersions was investigated. The poorly aqueous soluble diazepam was used as a lipophilic model drug. The release of diazepam and sugar carrier was determined to study the mechanisms governing dissolution behaviour.

  6. Anomalous dissolution behaviour of tablets prepared from sugar glass-based solid dispersions

    NARCIS (Netherlands)

    Van Drooge, D.J.; Hinrichs, W.L.J.; Frijlink, H.W.

    2004-01-01

    In this study, anomalous dissolution behaviour of tablets consisting of sugar glass dispersions was investigated. The poorly aqueous soluble diazepam was used as a lipophilic model drug. The release of diazepam and sugar carrier was determined to study the mechanisms governing dissolution behaviour.

  7. Solid-phase synthesis, characterization, and cellular activities of collagen-model nanodiamond-peptide conjugates.

    Science.gov (United States)

    Knapinska, Anna M; Tokmina-Roszyk, Dorota; Amar, Sabrina; Tokmina-Roszyk, Michal; Mochalin, Vadym N; Gogotsi, Yury; Cosme, Patrick; Terentis, Andrew C; Fields, Gregg B

    2015-05-01

    Nanodiamonds (NDs) have received considerable attention as potential drug delivery vehicles. NDs are small (∼5 nm diameter), can be surface modified in a controllable fashion with a variety of functional groups, and have little observed toxicity in vitro and in vivo. However, most biomedical applications of NDs utilize surface adsorption of biomolecules, as opposed to covalent attachment. Covalent modification provides reliable and reproducible ND-biomolecule ratios, and alleviates concerns over biomolecule desorption prior to delivery. The present study has outlined methods for the efficient solid-phase conjugation of ND to peptides and characterization of ND-peptide conjugates. Utilizing collagen-derived peptides, the ND was found to support or even enhance the cell adhesion and viability activities of the conjugated sequence. Thus, NDs can be incorporated into peptides and proteins in a selective manner, where the presence of the ND could potentially enhance the in vivo activities of the biomolecule it is attached to.

  8. Heterogeneity of DNA Distribution in Diploid Cells: A New Predicitive Discriminant Factor for Solid Tumour Behaviour

    Directory of Open Access Journals (Sweden)

    Jacques Assailly

    1999-01-01

    distribution of diploid cells seems to quantitate probable genetic instability as a function of clinical evolution such as tumour recurrence, and suggests the possible presence of aneuploid stemlines in a heterogeneous tumour, even if a diploid DNA histogram is observed in a single sample. From standardized C1 and C2 canonical discriminant function coefficients, a DNA heterogeneity index (2c‐HI is proposed to characterize diploid cells providing a descriptive and predictive discriminant factor for solid tumour behaviour.

  9. Solid lipid nanoparticles for oral drug delivery: chitosan coating improves stability, controlled delivery, mucoadhesion and cellular uptake.

    Science.gov (United States)

    Luo, Yangchao; Teng, Zi; Li, Ying; Wang, Qin

    2015-05-20

    The poor stability of solid lipid nanoparticles (SLN) under acidic condition resulted in large aggregation in gastric environment, limiting their application as oral delivery systems. In this study, a series of SLN was prepared to investigate the effects of surfactant/cosurfactant and chitosan coating on their physicochemical properties as well as cellular uptake. SLN was prepared from Compritol 888 ATO using a low-energy method combining the solvent-diffusion and hot homogenization technique. Poloxamer 188 and polyethylene glycol (PEG) were effective emulsifiers to produce SLN with better physicochemical properties than SLN control. Chitosan-coated SLN exhibited the best stability under acidic condition by forming a thick layer around the lipid core, as clearly observed by transmission electron microscope. The intermolecular interactions in different formulations were monitored by Fourier transform infrared spectroscopy. Chitosan coating also significantly improved the mucoadhesive property of SLN as determined by Quartz Crystal Microbalance. In vitro drug delivery assays, cytotoxicity, and cellular uptake of SLN were studied by incorporating coumarin 6 as a fluorescence probe. Overall, chitosan-coated SLN was superior to other formulations and held promising features for its application as a potential oral drug delivery system for hydrophobic drugs.

  10. Analysis of the Rheological Behaviour of Selected Semi-Solid Slag Systems in Blast Furnace Flow Conditions

    Directory of Open Access Journals (Sweden)

    Migas P.

    2015-04-01

    Full Text Available The rheological properties of liquid and semi-solid systems of slag and hot metal in a blast furnace are extremely important from the perspective of their dripping in the unit. The rheological nature and the values of the dynamic viscosity coefficient of liquid and semi-solid phases - slag and hot metal - determine the permeability of the zones in which those systems exist. The modelling of dripping processes and e.g. static and dynamic holding/retention of liquid in the bed, requires an accurate description of the rheological behaviour of slag and iron systems. Determining the liquid flow through the lump bed of the blast furnace is based on the assumption that liquids in the unit in the whole range of their occurrence are similar to a Newtonian ideal liquid. This study presents an analysis of the findings of high-temperature rheometric measurements of CaO-SiO2-Al2O3-MgO systems, liquid, semi-solid slags of the blast furnace type doped with TiO2 and solids in the form of TiN. The tests were performed within a temperature range of 1310-1490°C. Also measurement results for glycerol solutions with concentrations of 86% and 100% at the ambient temperature, simulating blast furnace slags with various contents of solids - PC, anthracite - are presented.

  11. Delivery of kinesin spindle protein targeting siRNA in solid lipid nanoparticles to cellular models of tumor vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Ying, Bo; Campbell, Robert B., E-mail: robert.campbell@mcphs.edu

    2014-04-04

    Highlights: • siRNA-lipid nanoparticles are solid particles not lipid bilayers with aqueous core. • High, but not low, PEG content can prevent nanoparticle encapsulation of siRNA. • PEG reduces cellular toxicity of cationic nanoparticles in vitro. • PEG reduces zeta potential while improving gene silencing of siRNA nanoparticles. • Kinesin spindle protein can be an effective target for tumor vascular targeting. - Abstract: The ideal siRNA delivery system should selectively deliver the construct to the target cell, avoid enzymatic degradation, and evade uptake by phagocytes. In the present study, we evaluated the importance of polyethylene glycol (PEG) on lipid-based carrier systems for encapsulating, and delivering, siRNA to tumor vessels using cellular models. Lipid nanoparticles containing different percentage of PEG were evaluated based on their physical chemical properties, density compared to water, siRNA encapsulation, toxicity, targeting efficiency and gene silencing in vitro. siRNA can be efficiently loaded into lipid nanoparticles (LNPs) when DOTAP is included in the formulation mixture. However, the total amount encapsulated decreased with increase in PEG content. In the presence of siRNA, the final formulations contained a mixed population of particles based on density. The major population which contains the majority of siRNA exhibited a density of 4% glucose, and the minor fraction associated with a decreased amount of siRNA had a density less than PBS. The inclusion of 10 mol% PEG resulted in a greater amount of siRNA associated with the minor fraction. Finally, when kinesin spindle protein (KSP) siRNA was encapsulated in lipid nanoparticles containing a modest amount of PEG, the proliferation of endothelial cells was inhibited due to the efficient knock down of KSP mRNA. The presence of siRNA resulted in the formation of solid lipid nanoparticles when prepared using the thin film and hydration method. LNPs with a relatively modest amount of

  12. New insights into the thermal behaviour of organic ionic plastic crystals: magnetic resonance imaging of polycrystalline morphology alterations induced by solid-solid phase transitions.

    Science.gov (United States)

    Romanenko, Konstantin; Pringle, Jennifer M; O'Dell, Luke A; Forsyth, Maria

    2015-07-15

    Organic ionic plastic crystals (OIPCs) show strong potential as solid-state electrolytes for lithium battery applications, demonstrating promising electrochemical performance and eliminating the need for a volatile and flammable liquid electrolyte. The ionic conductivity (σ) in these systems has recently been shown to depend strongly on polycrystalline morphology, which is largely determined by the sample's thermal history. [K. Romanenko et al., J. Am. Chem. Soc., 2014, 136, 15638]. Tailoring this morphology could lead to conductivities sufficiently high for battery applications, so a more complete understanding of how phenomena such as solid-solid phase transitions can affect the sample morphology is of significant interest. Anisotropic relaxation of nuclear spin magnetisation provides a new MRI based approach for studies of polycrystalline materials at both a macroscopic and molecular level. In this contribution, morphology alterations induced by solid-solid phase transitions in triisobutyl(methyl)phosphonium bis(fluorosulfonyl)imide (P1444FSI) and diethyl(methyl)(isobutyl)phosphonium hexafluorophosphate (P1224PF6) are examined using magnetic resonance imaging (MRI), alongside nuclear magnetic resonance (NMR) spectroscopy, diffusion measurements and conductivity data. These observations are linked to molecular dynamics and structural behaviour crucial for the conductive properties of OIPCs. A distinct correlation is established between the conductivity at a given temperature, σ(T), and the intensity of the narrow NMR signal that is attributed to a mobile fraction, fm(T), of ions in the OIPC. To explain these findings we propose an analogy with the well-studied relationship between permeability (k) and void fraction (θ) in porous media, with k(θ) commonly quantified by a power-law dependence that can also be employed to describe σ(fm).

  13. Behaviour of rare gases in solids at high temperature; Comportement des gaz rares dans les solides a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Blin, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    In this article a number of simple results regarding the solubility and displacement of rare gases in solids have been assembled. These results were obtained from elementary considerations on highly compressed gases and on dislocations. They provide a better understanding of the now fairly numerous experiments dealing with the swelling of irradiated fuels, this swelling being due to the presence of a high proportion of gases in the fission products. Finally, the chances of success of the various methods which may be devised to diminish the swelling are examined. (author) [French] Nous avons rassemble dans ce texte un certain nombre de resultats simples relatifs a la solubilite et au deplacement des gaz rares dans les solides. Ces resultats ont ete obtenus par des considerations elementaires sur les gaz tres comprimes et sur les dislocations. Ils permettent de mieux comprendre les experiences, maintenant assez nombreuses, qui ont trait au gonflement des combustibles irradies; gonflement qui est du a la presence d'une forte proportion de gaz dans les produits de fission. On examine finalement les chances de succes des differents moyens que l'on peut imaginer pour attenuer le gonflement. (auteur)

  14. Hydrodynamic Behaviour of a Gas-Solid Air-loop Stripper

    Institute of Scientific and Technical Information of China (English)

    刘梦溪; 卢春喜; 时铭显

    2004-01-01

    In this paper, the principles of airlift loop reactor in gas-liquid and gas-liquid-solid systems are extended to gas-solid system. The models on bed average voidage in draft tube and the particle circulation velocity in a gas-solid loop reactor are deduced. The experiments are also conducted on a Φ600mm×7000mm reactor. The catalyst voidage and catalyst circulation velocity are measured at different radial and axial positions in draft tube and annulus, respectively. The experimental data are analyzed systemically and represented satisfactorily by the proposed models.

  15. Manufacturing processes of cellular metals. Part II. Solid route, metals deposition, other processes; Procesos de fabricacion de metales celulares. Parte II: Via solida, deposicion de metales otros procesos

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, P.; Cruz, L. J.; Coleto, J.

    2009-07-01

    At the first part of this paper review a description about cellular metal processes by liquid route, was made. In this second part, solid processes and metals deposition are described. In similar way, the different kind of processes in each case are reviewed; making a short description about the main parameters involved and the advantages and drawbacks in each of them. (Author) 147 refs.

  16. Synthesis, characterization and thermal behaviour on solid pyruvates of light trivalent lanthanides; Sintese, caracterizacao e comportamento termico dos piruvatos de lantanideos leves no estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, A.B.; Carvalho, C.T. de; Ionashiro, M. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica]. E-mail: massaoi@iq.unesp.br; Rodrigues, E.C. [Fundacao Educacional de Barretos, SP (Brazil); Ionashiro, E.Y.; Bannach, G. [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil). Dept. de Quimica

    2007-07-01

    Solid State Ln-L compounds, where Ln stands for light trivalent lanthanides (La - Gd) and L is pyruvate, have been synthesized. Thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), X-Ray powder diffractometry, infrared spectroscopy, elemental analysis, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, ligand denticity, thermal behaviour and thermal decomposition of the isolated compounds. (author)

  17. Creep behaviour of porous metal supports for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Boccaccini, Dino; Frandsen, Henrik Lund; Sudireddy, Bhaskar Reddy

    2014-01-01

    a significant role affecting the creep behaviour of the metal supports, in particular the stress exponent. The variation of the elastic modulus as function of temperature and oxidation conditions was also determined by a high temperature impulse excitation technique. Additionally nano-indentation testing...... was performed in the metal oxide interface to elucidate the mechanical properties of the oxide scales and qualitative information about the oxide scale-metal interfacial bonding. Copyright © 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved....

  18. Corrosion Behaviour of A380 Aluminiun Alloy by Semi-Solid Rheocasting

    Science.gov (United States)

    Forn, A.; Rupérez, E.; Baile, M. T.; Campillo, M.; Menargues, S.; Espinosa, I.

    2007-04-01

    A comparative study was performed on the corrosion behavior of a component of A380 aluminium alloy obtained by Semi-Solid Rheocasting (SSR). The effect of heat treatments T5 and T6 on corrosion resistance was compared with components without heat treatment by SSR processes. Corrosion studies were performed using an acetic acid salt spray test, impedance measurements and polarization curves using a 3,5%Na Cl test solution. The corrosion progress is described by micrographic analysis.

  19. TIME–HARMONIC BEHAVIOUR OF CRACKED PIEZOELECTRIC SOLID BY BOUNDARY INTEGRAL EQUATION METHOD

    Directory of Open Access Journals (Sweden)

    Rangelov Tsviatko

    2014-03-01

    Full Text Available Anti-plane cracked functionally graded finite piezoelectric solid under time-harmonic elecromechanical load is studied by a non-hypersingular traction boundary integral equation method (BIEM. Exponentially varying material properties are considered. Numerical solutions are obtained by using Mathematica. The dependance of the intensity factors (IF - mechanical stress intensity factor (SIF and electrical field intensity factor (FIF on the inhomogeneous material parameters, on the type and frequency of the dynamic load and on the crack position are analyzed by numerical illustrative examples

  20. Heterogeneous catalytic materials solid state chemistry, surface chemistry and catalytic behaviour

    CERN Document Server

    Busca, Guido

    2014-01-01

    Heterogeneous Catalytic Materials discusses experimental methods and the latest developments in three areas of research: heterogeneous catalysis; surface chemistry; and the chemistry of catalysts. Catalytic materials are those solids that allow the chemical reaction to occur efficiently and cost-effectively. This book provides you with all necessary information to synthesize, characterize, and relate the properties of a catalyst to its behavior, enabling you to select the appropriate catalyst for the process and reactor system. Oxides (used both as catalysts and as supports for cata

  1. Relating solubility data of parabens in liquid PEG 400 to the behaviour of PEG 4000-parabens solid dispersions.

    Science.gov (United States)

    Unga, Johan; Tajarobi, Farhad; Norder, Ove; Frenning, Göran; Larsson, Anette

    2009-10-01

    The solid state behaviour of polyethylene glycol 4000 (PEG 4000) and dispersions of a homologous series of parabens (methyl- (MP), ethyl- (EP), propyl- (PP) and butyl- (BP)) were examined and compared to the paraben solubility in liquid PEG 400. Dispersions were prepared by co-melting different amounts of paraben (5-80% (w/w)) and PEG 4000 and were studied using a combination of differential scanning calorimetry (DSC) and small and wide angle X-ray diffraction (SAXD/WAXD). Depending on the concentration of parabens in the dispersions, DSC showed melting peaks from folded and unfolded forms of PEG, a eutectic melting and melting of pure parabens. The fraction of folded PEG increased and the melting temperatures of both PEG forms decreased with increasing paraben content. In an apparent phase diagram of PP-PEG dispersions a eutectic mixture appeared above 5% PP. In addition, a melting peak corresponding to the paraben appeared for dispersion containing more than 60% PP. Similar phase diagrams were shown for the other parabens. The SAXD data and a 1D correlation function analysis revealed that MP and BP were incorporated into the amorphous domains of the lamellae of solid PEG to a higher degree than EP and PP. In addition, the lamellae thickness of PEG and the fraction of amorphous domains increased more for MP and BP compared to EP and PP. BP showed the highest solubility of the parabens followed by MP, EP and PP in both liquid and solid PEG. Furthermore, the thickness of the amorphous domains of the PEG in the different parabens-PEG dispersions could be correlated to the solubility in liquid PEG 400.

  2. Thermal/moisture-related stresses and fracture behaviour in solid wood members during forced drying

    DEFF Research Database (Denmark)

    Larsen, Finn

    of wood without injury to the timber itself. When solid wood products are dried from a green condition down to an average moisture content level close to the service life conditions of the final product, significant moisture-induced stresses and related fracturing can occur. The drying stresses arise.......e. the possibility of driving mechano-sorptive strains back to their original state, was studied then by use of the verified model. Kiln-drying experiments were carried out, ina specially designed climate chamber under well-defined climatic conditions, allowing the climatic variation limits for crack initiation...... to be identified. The critical tensile stresses were determined by means of simulations and were compared with the levels of tensile strength found in tests of tensile strength carried out at the same temperature levels. Tensile strength is highly dependent upon the temperature! Water flux in the tangential...

  3. Scale Effects on Quasi-Steady Solid Rocket Internal Ballistic Behaviour

    Directory of Open Access Journals (Sweden)

    David R. Greatrix

    2010-11-01

    Full Text Available The ability to predict with some accuracy a given solid rocket motor’s performance before undertaking one or several costly experimental test firings is important. On the numerical prediction side, as various component models evolve, their incorporation into an overall internal ballistics simulation program allows for new motor firing simulations to take place, which in turn allows for updated comparisons to experimental firing data. In the present investigation, utilizing an updated simulation program, the focus is on quasi-steady performance analysis and scale effects (influence of motor size. The predicted effects of negative/positive erosive burning and propellant/casing deflection, as tied to motor size, on a reference cylindrical-grain motor’s internal ballistics, are included in this evaluation. Propellant deflection has only a minor influence on the reference motor’s internal ballistics, regardless of motor size. Erosive burning, on the other hand, is distinctly affected by motor scale.

  4. Continuous supercritical synthesis and dielectric behaviour of the whole BST solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Reveron, H; Elissalde, C; Aymonier, C; Bousquet, C; Maglione, M; Cansell, F [Institut de Chimie de la Matiere Condensee de Bordeaux (ICMCB), CNRS-UPR 9048, Bordeaux I University, 87, avenue du Dr Schweitzer, 33608 PESSAC Cedex (France)

    2006-07-28

    In this study we show that pure and well crystallized nanoparticles of Ba{sub x}Sr{sub 1-x}TiO{sub 3} (BST) can be synthesized over the entire range of composition through the hydrolysis and further crystallization of alkoxide precursors under supercritical conditions. To our knowledge, this is the first time that the whole ferroelectric solid solution has been produced in a continuous way, using the same experimental conditions. The composition of the powder can be easily controlled by adjusting the feed solution composition. The powders consist of soft-aggregated monocrystalline nanoparticles with an average particle size ranging from {approx}20 to 40 nm. Ferroelectric ceramics with accurately adjustable Curie temperature (100-390 K) can thus be obtained by sintering.

  5. Effect of solid lubricants on friction and wear behaviour of alloyed gray cast iron

    Indian Academy of Sciences (India)

    Aravind Vadiraj; M Kamaraj; V S Sreenivasan

    2012-10-01

    Friction and wear behaviour of MoS2, boric acid, graphite and TiO2 at four different sliding speeds (1.0, 1.5, 2.0, 2.5 m/s) has been compared with dry sliding condition. MoS2 and graphite show 30 to 50% reduction in mass loss compared to other lubricants at all sliding speeds. Friction coefficient reduces with increase in sliding speeds for all the conditions. Friction coefficient of dry as well as lubricant coated samples varies from 0.2 to 0.55 with MoS2 showing the lowest value (0.2). Boric acid and TiO2 coated samples show high friction coefficients at higher sliding speeds due to poor lubricity and adherence. This could also be due to sliding resistance offered by lubricant coated samples with predominant asperities interaction. MoS2 and graphite coated samples also generated lowest frictional temperature compared to other conditions.

  6. Agglomeration behaviour of steel plants solid waste and its effect on sintering performance

    Directory of Open Access Journals (Sweden)

    Prince Kumar Singh

    2017-07-01

    Full Text Available Recycling has been the fascinating topic among the researchers for all times. The present study shows the recycling of steel plant's solid wastes as blast furnace flue dust and sludge towards agglomeration and their use in the production of sinter. These wastes consist of metal oxides and coke fines as a valuable material with some alkali oxides. Using these wastes as it is in the form of fines exacerbate the further processing. Pellets of these wastes are prepared with three types of binders as molasses, dextrin and bentonite. The result reveals that properties as compressive strength, shatter strength, are better in the case of bentonite binder having the productivity of the disc pelletizer machine as 75. After that, these macro pellets used for sintering with iron ore and other ingredients in pot type, down draft laboratory grade sintering machine, which shows very high productivity and good mechanical properties of the sinter as well. The microstructural analysis reveals the presence of re-oxidized hematite and a little bit of a magnetite phase with some slag phases, which confirmed later by XRD analysis. Results also show the decrease in coke rate, i.e. coke consumption to produce sinter and at the same time, this process is highly eco-friendly.

  7. Temperature-dependent modification of muscle precursor cell behaviour is an underlying reason for lasting effects on muscle cellularity and body growth of teleost fish.

    Science.gov (United States)

    Steinbacher, Peter; Marschallinger, Julia; Obermayer, Astrid; Neuhofer, Alois; Sänger, Alexandra M; Stoiber, Walter

    2011-06-01

    Temperature is an important factor influencing teleost muscle growth, including a lasting ('imprinted') influence of embryonic thermal experience throughout all further life. However, little is known about the cellular processes behind this phenomenon. The study reported here used digital morphometry and immunolabelling for Pax7, myogenin and H3P to quantitatively examine the effects of thermal history on muscle precursor cell (MPC) behaviour and muscle growth in pearlfish (Rutilus meidingeri) until the adult stage. Fish were reared at three different temperatures (8.5, 13 and 16°C) until hatching and subsequently kept under the same (ambient) thermal conditions. Cellularity data were combined with a quantitative analysis of Pax7+ MPCs including those that were mitotically active (Pax7+/H3P+) or had entered differentiation (Pax7+/myogenin+). The results demonstrate that at hatching, body lengths, fast and slow muscle cross-sectional areas and fast fibre numbers are lower in fish reared at 8.5 and 13°C than at 16°C. During the larval period, this situation changes in the 13°C-fish, so that these fish are finally the largest. The observed effects can be related to divergent cellular mechanisms at the MPC level that are initiated in the embryo during the imprinting period. Embryos of 16°C-fish have reduced MPC proliferation but increased differentiation, and thus give rise to larger hatchlings. However, their limited MPC reserves finally lead to smaller adults. By contrast, embryos of 13°C-fish and, to a lesser extent, 8.5°-fish, show enhanced MPC proliferation but reduced differentiation, thus leading to smaller hatchlings but allowing for a larger MPC pool that can be used for enhanced post-hatching growth, finally resulting in larger adults.

  8. Catalytic and electrochemical behaviour of solid oxide fuel cell operated with simulated-biogas mixtures

    Science.gov (United States)

    Dang-Long, T.; Quang-Tuyen, T.; Shiratori, Y.

    2016-06-01

    Being produced from organic matters of wastes (bio-wastes) through a fermentation process, biogas mainly composed of CH4 and CO2 and can be considered as a secondary energy carrier derived from solar energy. To generate electricity from biogas through the electrochemical process in fuel cells is a state-of-the-art technology possessing higher energy conversion efficiency without harmful emissions compared to combustion process in heat engines. Getting benefits from high operating temperature such as direct internal reforming ability and activation of electrochemical reactions to increase overall system efficiency, solid oxide fuel cell (SOFC) system operated with biogas becomes a promising candidate for distributed power generator for rural applications leading to reductions of environmental issues caused by greenhouse effects and bio-wastes. CO2 reforming of CH4 and electrochemical oxidation of the produced syngas (H2-CO mixture) are two main reaction processes within porous anode material of SOFC. Here catalytic and electrochemical behavior of Ni-ScSZ (scandia stabilized-zirconia) anode in the feed of CH4-CO2 mixtures as simulated-biogas at 800 °C were evaluated. The results showed that CO2 had strong influences on both reaction processes. The increase in CO2 partial pressure resulted in the decrease in anode overvoltage, although open-circuit voltage was dropped. Besides that, the simulation result based on a power-law model for equimolar CH4-CO2 mixture revealed that coking hazard could be suppressed along the fuel flow channel in both open-circuit and closed-circuit conditions.

  9. Catalytic and electrochemical behaviour of solid oxide fuel cell operated with simulated-biogas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Dang-Long, T., E-mail: 3TE14098G@kyushu-u.ac.jp [Department of Hydrogen Energy Systems, Faculty of Engineering, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); Quang-Tuyen, T., E-mail: tran.tuyen.quang.314@m.kyushu-u.ac.jp [International Research Center for Hydrogen Energy, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); Shiratori, Y., E-mail: shiratori.yusuke.500@m.kyushu-u.ac.jp [Department of Hydrogen Energy Systems, Faculty of Engineering, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); International Research Center for Hydrogen Energy, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan)

    2016-06-03

    Being produced from organic matters of wastes (bio-wastes) through a fermentation process, biogas mainly composed of CH{sub 4} and CO{sub 2} and can be considered as a secondary energy carrier derived from solar energy. To generate electricity from biogas through the electrochemical process in fuel cells is a state-of-the-art technology possessing higher energy conversion efficiency without harmful emissions compared to combustion process in heat engines. Getting benefits from high operating temperature such as direct internal reforming ability and activation of electrochemical reactions to increase overall system efficiency, solid oxide fuel cell (SOFC) system operated with biogas becomes a promising candidate for distributed power generator for rural applications leading to reductions of environmental issues caused by greenhouse effects and bio-wastes. CO{sub 2} reforming of CH{sub 4} and electrochemical oxidation of the produced syngas (H{sub 2}–CO mixture) are two main reaction processes within porous anode material of SOFC. Here catalytic and electrochemical behavior of Ni-ScSZ (scandia stabilized-zirconia) anode in the feed of CH{sub 4}–CO{sub 2} mixtures as simulated-biogas at 800 °C were evaluated. The results showed that CO{sub 2} had strong influences on both reaction processes. The increase in CO{sub 2} partial pressure resulted in the decrease in anode overvoltage, although open-circuit voltage was dropped. Besides that, the simulation result based on a power-law model for equimolar CH{sub 4}−CO{sub 2} mixture revealed that coking hazard could be suppressed along the fuel flow channel in both open-circuit and closed-circuit conditions.

  10. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

    Science.gov (United States)

    K S, Joshy; Sharma, Chandra P; Kalarikkal, Nandakumar; Sandeep, K; Thomas, Sabu; Pothen, Laly A

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Effect of composition, microstructure and component thickness on the oxidation behaviour of laves phase strengthened interconnect steel for solid oxide fuel cells (SOFC)

    OpenAIRE

    2013-01-01

    The high-Cr, Laves phase strengthened ferritic steel, Crofer 22 H, has recently been proposed as construction material for interconnects in solid oxide fuel cells (SOFC). Aim of the present investigation was to get more insight in the details of SOFC relevant properties, mostly oxidation behaviour and oxide electronic conductivity, in simulated SOFC service environments as a function of temperature, with main emphasis on the most commonly used operating temperature 800°C. The present studies ...

  12. Friction behaviour of solid oxide lubricants as second phase in alpha-Al2O3 and stabilised ZrO2 composites

    NARCIS (Netherlands)

    Kerkwijk, B.; de la Luz Garcia-Curiel, M.M.; van Zyl, W.E.; Winnubst, Aloysius J.A.; Mulder, E.J.; Schipper, Dirk J.; Verweij, H.

    2004-01-01

    The influence of metal oxide additives within alumina (¿-Al2O3) and yttria-stabilised tetragonal zirconia (Y-TZP) matrices was studied with respect to the tribological behaviour of the composites. The solid lubricants CuO, ZnO, MgO, MnO2 and B2O3 were added in sufficiently small quantities (1 or 5

  13. Cellular behaviour of hepatocyte-like cells from nude mouse bone marrow-derived mesenchymal stem cells on galactosylated poly(D,L-lactic-co-glycolic acid).

    Science.gov (United States)

    Roh, Hyun; Yang, Dae Hyeok; Chun, Heung Jae; Khang, Gilson

    2015-07-01

    Previously, the galactosylation of poly(d,l-lactic-co-glycolic acid) (PLGA) surface was accomplished by grafting allylamine (AA), using inductively coupled plasma-assisted chemical vapour deposition (ICP-CVD) and conjugating lactobionic acid (LA) with AA via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS) activation for hepatic tissue-engineering purposes. As a continuation study, the cellular behaviour of hepatocyte-like cells (HLCs) on the surface of the galactosylated PLGA were investigated. Nude mouse bone marrow-derived mesenchymal stem cells (MSCs) were cultured under hepatogenic conditions and the differentiated cells were characterized by reverse-transcription polymerase chain reaction (RT-PCR), immunofluorescence and periodic acid-Schiff (PAS) staining. Galactosylated PLGA enhanced the proliferation rate of HLCs compared to the control; HLCs on the surface of the sample became aggregated and formed spheroids after 3 days of culture. A large number of cells on the surface of the sample exhibited increased liver-specific functional activities, such as albumin and urea secretions. In addition, multicellular spheroids in the sample strongly expressed phospholyated focal adhesion kinase (pFAK) (cell-matrix interactions), E-cadherin (cell-cell interactions) and connexin 32 (Cox32; gap junction).

  14. Rapid solid-phase microwave synthesis of highly photoluminescent nitrogen-doped carbon dots for Fe3+ detection and cellular bioimaging

    Science.gov (United States)

    He, Guili; Xu, Minghan; Shu, Mengjun; Li, Xiaolin; Yang, Zhi; Zhang, Liling; Su, Yanjie; Hu, Nantao; Zhang, Yafei

    2016-09-01

    Recently, carbon dots (CDs) have been playing an increasingly important role in industrial production and biomedical field because of their excellent properties. As such, finding an efficient method to quickly synthesize a large scale of relatively high purity CDs is of great interest. Herein, a facile and novel microwave method has been applied to prepare nitrogen doped CDs (N-doped CDs) within 8 min using L-glutamic acid as the sole reaction precursor in the solid phase condition. The as-prepared N-doped CDs with an average size of 1.64 nm are well dispersed in aqueous solution. The photoluminescence of N-doped CDs is pH-sensitive and excitation-dependent. The N-doped CDs show a strong blue fluorescence with relatively high fluorescent quantum yield of 41.2%, which remains stable even under high ionic strength. Since the surface is rich in oxygen-containing functional groups, N-doped CDs can be applied to selectively detect Fe3+ with the limit of detection of 10-5 M. In addition, they are also used for cellular bioimaging because of their high fluorescent intensity and nearly zero cytotoxicity. The solid-phase microwave method seems to be an effective strategy to rapidly obtain high quality N-doped CDs and expands their applications in ion detection and cellular bioimaging.

  15. A Comparative Electrochemical Behaviour Study and Analytical Detection of the p-Nitrophenol Using Silver Solid Amalgam, Mercury, and Silver Electrodes

    Directory of Open Access Journals (Sweden)

    Djenaine De Souza

    2011-01-01

    Full Text Available This work reports a comparative electrochemical behaviour study and p-nitrophenol analytical detection using silver solid amalgam, hanging dropping mercury, and silver electrodes. For this, square wave voltammetry was employed, where the analytical responses and the redox mechanisms could be compared for reduction processes of 4-nitrophenol by analysis of the voltammetric responses. The analytical performance of the electrode was evaluated and detection and quantification limits, recovery percentages, repeatability, and reproducibility for the silver solid amalgam and hanging dropping mercury electrodes presented similar values; the results presented for the silver electrode indicated worse analytical parameters than the other electrodes. The results indicate that the silver solid amalgam electrode can be considered a suitable tool and an interesting alternative for the analytical determination of 4-nitrophenol, as well as for the determination of other biological and environmentally interesting compounds that present analytical responses on mercury surfaces.

  16. Stomach Temperature Records Reveal Nursing Behaviour and Transition to Solid Food Consumption in an Unweaned Mammal, the Harbour Seal Pup (Phoca vitulina)

    Science.gov (United States)

    Sauvé, Caroline C.; Van de Walle, Joanie; Hammill, Mike O.; Arnould, John P. Y.; Beauplet, Gwénaël

    2014-01-01

    Knowledge of milk transfer from mother to offspring and early solid food ingestions in mammals allows for a greater understanding of the factors affecting transition to nutritional independence and pre-weaning growth and survival. Yet studies monitoring suckling behaviour have often relied on visual observations, which might not accurately represent milk intake. We assessed the use of stomach temperature telemetry to monitor suckling and foraging behaviour in free-ranging harbour seal (Phoca vitulina) pups during lactation. Stomach temperature declines were analysed using principal component and cluster analyses, as well as trials using simulated stomachs resulting in a precise classification of stomach temperature drops into milk, seawater and solid food ingestions. Seawater and solid food ingestions represented on average 15.3±1.6% [0–40.0%] and 0.7±0.2% [0–13.0%], respectively, of individual ingestions. Overall, 63.7% of milk ingestions occurred while the pups were in the water, of which 13.9% were preceded by seawater ingestion. The average time between subsequent ingestions was significantly less for seawater than for milk ingestions. These results suggest that seawater ingestion might represent collateral ingestion during aquatic suckling attempts. Alternatively, as solid food ingestions (n = 19) were observed among 7 pups, seawater ingestion could result from missed prey capture attempts. This study shows that some harbour seals start ingesting prey while still being nursed, indicating that weaning occurs more gradually than previously thought in this species. Stomach temperature telemetry represents a promising method to study suckling behaviour in wild mammals and transition to nutritional independence in various endotherm species. PMID:24587327

  17. Stomach temperature records reveal nursing behaviour and transition to solid food consumption in an unweaned mammal, the harbour seal pup (Phoca vitulina.

    Directory of Open Access Journals (Sweden)

    Caroline C Sauvé

    Full Text Available Knowledge of milk transfer from mother to offspring and early solid food ingestions in mammals allows for a greater understanding of the factors affecting transition to nutritional independence and pre-weaning growth and survival. Yet studies monitoring suckling behaviour have often relied on visual observations, which might not accurately represent milk intake. We assessed the use of stomach temperature telemetry to monitor suckling and foraging behaviour in free-ranging harbour seal (Phoca vitulina pups during lactation. Stomach temperature declines were analysed using principal component and cluster analyses, as well as trials using simulated stomachs resulting in a precise classification of stomach temperature drops into milk, seawater and solid food ingestions. Seawater and solid food ingestions represented on average 15.3±1.6% [0-40.0%] and 0.7±0.2% [0-13.0%], respectively, of individual ingestions. Overall, 63.7% of milk ingestions occurred while the pups were in the water, of which 13.9% were preceded by seawater ingestion. The average time between subsequent ingestions was significantly less for seawater than for milk ingestions. These results suggest that seawater ingestion might represent collateral ingestion during aquatic suckling attempts. Alternatively, as solid food ingestions (n = 19 were observed among 7 pups, seawater ingestion could result from missed prey capture attempts. This study shows that some harbour seals start ingesting prey while still being nursed, indicating that weaning occurs more gradually than previously thought in this species. Stomach temperature telemetry represents a promising method to study suckling behaviour in wild mammals and transition to nutritional independence in various endotherm species.

  18. Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Joshy, K.S. [Department of Chemistry, CMS College Kottayam, Kerala (India); International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sharma, Chandra P. [Division of Biosurface Technology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Science and Technology, Poojappura, Thiruvananthapuram, Kerala (India); Kalarikkal, Nandakumar [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Sandeep, K. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Thomas, Sabu, E-mail: sabuchathukulam@yahoo.co.uk [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); School of Chemical Sciences, Mahatma Gandhi University, Kottayam 686 560, Kerala (India); Pothen, Laly A. [Department of Chemistry, Bishop Moore College, Mavelikkara, Kerala (India)

    2016-09-01

    Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66 ± 12.22 nm and modified solid lipid nanoparticles showed an average size of 265.61 ± 80.44 nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV. - Highlights: • SLN of AZT-SA, AZT-SA-AV was developed • Better drug loading efficacy • Good uptake.

  19. Antidepressant effects of curcumin and HU-211 coencapsulated solid lipid nanoparticles against corticosterone-induced cellular and animal models of major depression

    Directory of Open Access Journals (Sweden)

    He XL

    2016-10-01

    Full Text Available Xiaolie He,* Yanjing Zhu,* Mei Wang, Guoxin Jing, Rongrong Zhu, Shilong Wang Research Center for Translational Medicine at East Hospital, School of Life Science and Technology, Tongji University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: Major depression is a complex neuropsychiatric disorder with few treatment approaches. The use of nontargeted antidepressants induced many side effects with their low efficacy. A more precise targeting strategy is to develop nanotechnology-based drug delivery systems; hence, we employed solid lipid nanoparticles (SLNs to encapsulate HU-211 and curcumin (Cur. The antidepressant effects of the dual-drug nanoparticles (Cur/SLNs-HU-211 for major depression treatment were investigated in corticosterone-induced cellular and animal models of major depression. Cur/SLNs-HU-211 can effectively protect PC12 cells from corticosterone-induced apoptosis and can release more dopamine, which may be associated with the higher uptake of Cur/SLNs-HU-211 shown by cellular uptake behavior analysis. Additionally, Cur/SLNs-HU-211 significantly reduced the immobility time in forced swim test, enhanced fall latency in rotarod test, and improved the level of dopamine in mice blood. Cur/SLNs-HU-211 can deliver more Cur to the brain and thus produce a significant increase in neurotransmitters level in brain tissue, especially in the hippocampus and striatum. The results of Western blot and immunofluorescence revealed that Cur/SLNs-HU-211 can significantly enhance the expression of CB1, p-MEK1, and p-ERK1/2. Our study suggests that Cur/SLNs-HU-211 may have great potential for major depression treatment. Keywords: major depression, curcumin, HU-211, solid lipid nanoparticles, dopamine

  20. Antidepressant effects of curcumin and HU-211 coencapsulated solid lipid nanoparticles against corticosterone-induced cellular and animal models of major depression

    Science.gov (United States)

    He, Xiaolie; Zhu, Yanjing; Wang, Mei; Jing, Guoxin; Zhu, Rongrong; Wang, Shilong

    2016-01-01

    Major depression is a complex neuropsychiatric disorder with few treatment approaches. The use of nontargeted antidepressants induced many side effects with their low efficacy. A more precise targeting strategy is to develop nanotechnology-based drug delivery systems; hence, we employed solid lipid nanoparticles (SLNs) to encapsulate HU-211 and curcumin (Cur). The antidepressant effects of the dual-drug nanoparticles (Cur/SLNs-HU-211) for major depression treatment were investigated in corticosterone-induced cellular and animal models of major depression. Cur/SLNs-HU-211 can effectively protect PC12 cells from corticosterone-induced apoptosis and can release more dopamine, which may be associated with the higher uptake of Cur/SLNs-HU-211 shown by cellular uptake behavior analysis. Additionally, Cur/SLNs-HU-211 significantly reduced the immobility time in forced swim test, enhanced fall latency in rotarod test, and improved the level of dopamine in mice blood. Cur/SLNs-HU-211 can deliver more Cur to the brain and thus produce a significant increase in neurotransmitters level in brain tissue, especially in the hippocampus and striatum. The results of Western blot and immunofluorescence revealed that Cur/SLNs-HU-211 can significantly enhance the expression of CB1, p-MEK1, and p-ERK1/2. Our study suggests that Cur/SLNs-HU-211 may have great potential for major depression treatment. PMID:27757031

  1. Investigation and correlation of physical stability, dissolution behaviour and interaction parameter of amorphous solid dispersions of telmisartan: a drug development perspective.

    Science.gov (United States)

    Dukeck, R; Sieger, P; Karmwar, P

    2013-07-16

    The aim of this study was to investigate if amorphous solid dispersions of telmisartan, prepared in presence of different polymers, exhibit different structural and thermodynamic characteristics and whether these differences can be correlated to their physical stability (time to crystallisation) and dissolution behaviour. Amorphous samples were prepared by melt quenching. The resulting amorphous materials were characterised using X-ray diffraction, Raman spectroscopy and differential scanning calorimetry. All freshly prepared samples were completely X-ray amorphous (with a halo being the only feature in the diffractograms). The shape of the halos in the diffractograms varied suggesting structural variations in the near order of the molecules between the different amorphous solid dispersions (ASDs). Principal component analysis of the Raman spectra of the various ASD revealed that the samples clustered in the scores plot, again suggesting structural differences due to the presence of different drug-polymer interaction. The ranking of the samples with respect to physical stability and interaction parameter was: ASD of telmisartan:eudragit>ASD of telmisartan:soluplus>ASD of telmisartan:HPMC>ASD of telmisartan:PVP>amorphous telmisartan. The interaction parameter, calculated by using the Flory Huggins theory, showed a good correlation with the experimentally determined stability whereas a weak correlation was found with dissolution behaviour of different ASD. This study showed that correlation of physical stability and dissolution behaviour with calculated interaction parameter is possible for the same amorphous systems prepared by using different polymers. This could aid in selecting the most appropriate polymer for the development of optimised formulations containing amorphous drugs. It can be concluded that ASD prepared by using different polymers have different structural and thermal properties. These differences affect the physical stability and dissolution

  2. Solid bioneedle-delivered influenza vaccines are highly thermostable and induce both humoral and cellular immune responses.

    Directory of Open Access Journals (Sweden)

    Peter C Soema

    Full Text Available The potential of bioneedles to deliver influenza vaccines was investigated. Four influenza vaccine formulations were screened to determine the optimal formulation for use with bioneedles. The stability of the formulations after freeze-drying was checked to predict the stability of the influenza vaccines in the bioneedles. Subunit, split, virosomal and whole inactivated influenza (WIV vaccine were formulated and lyophilized in bioneedles, and subsequently administered to C57BL/6 mice. Humoral and cellular immune responses were assessed after vaccination. The thermostability of lyophilized vaccines was determined after one-month storage at elevated temperatures. Bioneedle influenza vaccines induced HI titers that are comparable to those induced by intramuscular WIV vaccination. Delivery by bioneedles did not alter the type of immune response induced by the influenza vaccines. Stability studies showed that lyophilized influenza vaccines have superior thermostability compared to conventional liquid vaccines, and remained stable after one-month storage at 60°C. Influenza vaccines delivered by bioneedles are a viable alternative to conventional liquid influenza vaccines. WIV was determined to be the most potent vaccine formulation for administration by bioneedles. Lyophilized influenza vaccines in bioneedles are independent of a cold-chain, due to their increased thermostability, which makes distribution and stockpiling easier.

  3. Effects of deformation temperature and rate on compressive deformation behaviour of Y 112 die cast aluminum alloy in semi-solid state

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-bo; HU Hong-jun; TANG Li-wen; DAI Bing

    2006-01-01

    The semi-solid compression deformation behaviour of Y112 die casting aluminum alloy with nondendritic structure obtained under the semi-solid isothermal treatment condition of 570 ℃ and 120 min, was investigated by means of Gleeble-1500 thermal-mechanical simulator. The results show that, when the strain is lower than 0.8, along with the compression strain increasing,the compression stress firstly increases rapidly, then decreases gradually. Under the condition of different deformation temperatures and deformation rates, the maximium compression stress is obtained simultaneously when the strain is 0.07 approximately.Furthermore, when the deformation rate keeps a constant, the compression stress decreases along with the deformation temperature increasing, and when the deformation temperature keeps a constant, the compression stress increases along with the deformation rate increasing.

  4. The Effect of Cellular Architecture on the Ductility and Strength of Metal Foams

    NARCIS (Netherlands)

    Mangipudi, K. R.; Onck, P. R.; Brechet, YJM; Embury, JD; Onck, PR

    2009-01-01

    A multiscale finite element model has been developed to study the fracture behaviour of two-dimensional random Voronoi structures. The influence of materials parameters and cellular architecture on the damage initiation and accumulation has been analyzed. The effect of the solid material's strain ha

  5. Mechanical behaviour of Al/Al_2O_3 composite in pseudo-semi-solid state during isothermal compression

    Institute of Scientific and Technical Information of China (English)

    CHENG Yuan-sheng; LUO Shou-jing

    2009-01-01

    To gain a better understanding of thixoforging for the Al_2O_3-37%Al composite, its mechanical behavior in the pseudo-semi-solid state was studied by isothermal compression tests. The results show that the values of peak stress obviously decrease with increasing temperature and decreasing strain rate. The compressive true stress-strain curves of the Al_2O_3-37%Al composite can be divided into four stages. They are rapidly ascending, decreasing, steady and slowly ascending. Moreover, the main deformation mechanism controlling deformation of the composite in the pseudo-semi-solid state is the sliding or rotary movement between solid particles.

  6. Alpha5beta1 integrin-fibronectin interactions specify liquid to solid phase transition of 3D cellular aggregates.

    Directory of Open Access Journals (Sweden)

    Carlos E Caicedo-Carvajal

    Full Text Available BACKGROUND: Tissue organization during embryonic development and wound healing depends on the ability of cells on the one hand to exchange adhesive bonds during active rearrangement and on the other to become fixed in place as tissue homeostasis is reached. Cells achieve these contradictory tasks by regulating either cell-cell adhesive bonds, mediated by cadherins, or cell-extracellular matrix (ECM connections, regulated by integrins. Integrin alpha5beta1 and soluble fibronectin (sFN are key players in cell-ECM force generation and in ECM polymerization. Here, we explore the interplay between integrin alpha5beta1 and sFN and its influence on tissue mechanical properties and cell sorting behavior. METHODOLOGY/PRINCIPAL FINDINGS: We generated a series of cell lines varying in alpha5beta1 receptor density. We then systematically explored the effects of different sFN concentrations on aggregate biomechanical properties using tissue surface tensiometry. We found previously unreported complex behaviors including the observation that interactions between fibronectin and integrin alpha5beta1 generates biphasic tissue cohesion profiles. Specifically, we show that at constant sFn concentration, aggregate cohesion increases linearly as alpha5beta1 receptor density is increased from low to moderate levels, producing a transition from viscoelastic-liquid to pseudo viscoelastic-solid behavior. However, further increase in receptor density causes an abrupt drop in tissue cohesion and a transition back to viscoelastic-liquid properties. We propose that this may be due to depletion of sFn below a critical value in the aggregate microenvironment at high alpha5beta1 levels. We also show that differential expression of alpha5beta1 integrin can promote phase-separation between cells. CONCLUSIONS/SIGNIFICANCE: The interplay between alpha5-integrin and sFn contributes significantly to tissue cohesion and, depending on their level of expression, can mediate a shift

  7. Cellular automata modelling of phase-change memories

    Institute of Scientific and Technical Information of China (English)

    Wanhua Yu; David Wright

    2008-01-01

    A novel approach to modelling phase-transition processes in phase change materials used for optical and electrical data storage applications is presented. The model is based on a cellular automaton (CA) approach to predict crystallization behaviour that is linked to thermal and electrical simulations to enable the study of the data writing and erasing processes. The CA approach is shown to be able to predict the evolution of the microstructure during the rapid heating and cooling cycles pertinent to data storage technology, and maps crystallization behaviour on the nanoscale. A simple example based on possible future nonvolatile phase-change random access solid-state memory is presented.

  8. Evidence for lattice strain and non-ideal behaviour in the (La1-xEux)PO4 solid solution from X-ray diffraction and vibrational spectroscopy

    Science.gov (United States)

    Geisler, Thorsten; Popa, Karin; Konings, Rudy

    2016-06-01

    The monazite-type solid solution of LaPO_4 and EuPO_4 has been studied by X-ray diffraction, infrared (IR) and Raman spectroscopic techniques. A substantial excess molar volume has been derived from the X-ray data, and the Raman and IR spectra show band broadening typical for mixing of cations of different size on the cation sublattice. The IR spectra were interpreted by the autocorrelation method and the excess autocorrelation parameter Δ{corr}^{ex} shows clear deviation from ideal solution behaviour, similar to the observed broadening of the Raman bands. The results can be interpreted in terms of local lattice strains resulting from the ion size effects of substitution of La^{3+} by Eu^{3+}, and correlate very well with calorimetric measurements of the excess enthalpy that was previously measured.

  9. Study on the crystallization behaviour and thermal stability of glass-ceramics used as solid oxide fuel cell-sealing materials

    Science.gov (United States)

    Gödeke, Dieter; Dahlmann, Ulf

    Glass ceramics are commonly used as sealing materials for planar solid oxide fuel cells (SOFCs). The major requirements of stack and module builders for these materials are the stability of the coefficient of thermal expansion (CTE), excellent bonding (sticking) behaviour and the absence of volatile ingredients, which can lead to changes of the material properties and the sealing ability. SCHOTT Electronic Packaging has developed special glasses and glass-ceramics for various solid oxide fuel cell designs and operating temperatures. The glass compositions are based on the system MgO-Al 2O 3-BaO-SiO 2-B 2O 3. In this study the evaluation of the developed materials was done by high temperature aging tests for up to 1000 h, high temperature XRD-studies and Rietveld calculations, combined with scanning-electron microscope analysis. Samples of these aged samples were chemically analysed by XRD and wet chemical methods. Results show that after thermal aging of the glasses barium silicates accompanied by barium-magnesium silicates are the major crystalline phases of the glasses. The crystal phases remain stable during high temperature aging tests, indicating a low driving force of material change. The experimental results are compared to phase diagrams by phenomenological and thermochemical considerations.

  10. A Study of Environmental Behaviour of the Wenceslau Braz (In the State of Paraná Population as Regards Urban Solid Waste

    Directory of Open Access Journals (Sweden)

    Mauro Januário

    2017-05-01

    Full Text Available The increasing and continuous production of waste in cities is a major concern for Public Managers. The implementation of the Environmental Public Policy has contributed to the responsible participation of all citizens. A partnership between the State University of Northern Paraná, in the Bandeirantes (PR campus, and the City of Wenceslau Braz (PR enabled the implementation of the "Green Partnership" Extension Project. Among the results, the implementation of selective collection of municipal solid waste was the most important. This study aims to understand the environmental behaviour of the population of Wenceslau Braz (PR after 15 months after the start of the selective collection service. A field research was done to study the environmental awareness of the people regarding the treatment of solid waste. Semi-structured questionnaires were applied by Community Health Agents, provided by the local Health Department, which, in the first week of December 2013, interviewed 310 people. The results show that 51% of respondents have a high interest in the issue of waste in nature. However, only 29% of them have substituted products for others to reduce the impact on the environment. Of the respondents, 1 in 5 do not commit to recycling at home. The data show that the lower the educational level, the greater the indifference to waste in nature. The study concludes that environmental education is the main tool to promote the overcoming of the current environmental problems, making possible the effective sustainability of our planet.

  11. Structural Behaviour of Solid Solutions in the NdAlO3-SrTiO3 System

    Science.gov (United States)

    Ohon, Natalia; Stepchuk, Roman; Blazhivskyi, Kostiantyn; Vasylechko, Leonid

    2017-02-01

    Single-phase mixed aluminates-titanates Nd1- x Sr x Al1- x Ti x O3 ( x = 0.3 ÷ 0.9) were prepared from stoichiometric amounts of constituent oxides Nd2O3, Al2O3, TiO2 and strontium carbonate SrCO3 by solid-state reaction technique in air at 1773 K. Crystal structure parameters of Nd1- x Sr x Al1- x Ti x O3 were refined by full-profile Rietveld refinement in space groups R overline{3} c ( x = 0.3, 0.5, 0.7 and 0.8) and Pm overline{3} m ( x = 0.9). Comparison of the obtained structural parameters with the literature data for the end members of the system NdAlO3 and SrTiO3 revealed formation of two kinds of solid solutions Nd1-xSrxAl1-xTixO3 with the cubic and rhombohedral perovskite structure. Morphotropic rhombohedral-to-cubic phase transition in Nd1-xSrxAl1-xTixO3 series occurs at x = 0.84. Based on the results obtained as well as the literature data for the parent compounds, the tentative phase diagram of the NdAlO3-SrTiO3 pseudo-binary system have been constructed.

  12. Simulation of the steady-state behaviour of a new design of a single planar Solid Oxide Fuel Cell

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2016-03-01

    Full Text Available The aim of the work was to develop a mathematical model for computing the steady-state voltage – current characteristics of a planar Solid Oxide Fuel Cell and to determine the performance of a new SOFC design. The design involves cross-flow bipolar plates. Each of the bipolar plates has an air channel system on one side and a fuel channel system on the other side. The proposed model was developed using the ANSYS-Fluent commercial Computational Fluid Dynamics (CFD software supported by additional Fuel Cell module. The results confirm that the model can well simulate the diagonal current path. The effects of temperature and gas flow through the channels and a Membrane Electrode Assembly (MEA structure were taken into account. It was shown that a significant increase of the MEA temperature at high current density can lead to hot spots formation and hence electrode damage.

  13. Thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned solid wastes with calcium hydroxide.

    Science.gov (United States)

    Tahiri, S; Albizane, A; Messaoudi, A; Azzi, M; Bennazha, J; Younssi, S Alami; Bouhria, M

    2007-01-01

    The thermal behaviour of chrome shavings and of sludges recovered after digestion of tanned wastes with Ca(OH)2 was studied. Ashes obtained after incineration of wastes at various temperatures were analysed by X-ray diffraction and EDX method. The main crystallized phases present in the ash obtained at 600 degrees C are Cr2O3 and NaCl. The diffractograms revealed an increase in the intensities of the chromium oxide peaks and a very notable decrease of the amount of sodium chloride at 1100 degrees C. EDX analysis revealed a total disappearance of the chlorine peak at this temperature. Scanning electron micrographs show that the waste lost its fibrous aspect when the temperature increases. Formation of aggregates was noted after 550 degrees C. Combustion of organic matters and decarbonation phenomenon are the main stages observed on GTA and DTA curves of sludges. These phenomena are, respectively, exothermic and endothermic. The diffractogram of sludges recorded at 550 degrees C, in the presence of a constant oxygen surplus, revealed the presence of CaCrO4 and CaCO3.

  14. Carbon deposition behaviour in metal-infiltrated gadolinia doped ceria electrodes for simulated biogas upgrading in solid oxide electrolysis cells

    Science.gov (United States)

    Duboviks, V.; Lomberg, M.; Maher, R. C.; Cohen, L. F.; Brandon, N. P.; Offer, G. J.

    2015-10-01

    One of the attractive applications for reversible Solid Oxide Cells (SOCs) is to convert CO2 into CO via high temperature electrolysis, which is particularly important for biogas upgrading. To improve biogas utility, the CO2 component can be converted into fuel via electrolysis. A significant issue for SOC operation on biogas is carbon-induced catalyst deactivation. Nickel is widely used in SOC electrodes for reasons of cost and performance, but it has a low tolerance to carbon deposition. Two different modes of carbon formation on Ni-based electrodes are proposed in the present work based on ex-situ Raman measurements which are in agreement with previous studies. While copper is known to be resistant towards carbon formation, two significant issues have prevented its application in SOC electrodes - namely its relatively low melting temperature, inhibiting high temperature sintering, and low catalytic activity for hydrogen oxidation. In this study, the electrodes were prepared through a low temperature metal infiltration technique. Since the metal infiltration technique avoids high sintering temperatures, Cu-Ce0.9Gd0.1O2-δ (Cu-CGO) electrodes were fabricated and tested as an alternative to Ni-CGO electrodes. We demonstrate that the performance of Cu-CGO electrodes is equivalent to Ni-CGO electrodes, whilst carbon formation is fully suppressed when operated on biogas mixture.

  15. Ballistic properties and burning behaviour of an ammonium perchlorate/guanidine nitrate/sodium nitrate airbag solid propellant

    Energy Technology Data Exchange (ETDEWEB)

    A. Ulas; G.A. Risha; K.K. Kuo [Middle East Technical University, Ankara (Turkey). Department of Mechanical Engineering

    2006-10-15

    An experimental investigation on the determination of ballistic properties and burning behavior of a composite solid propellant for airbag application was conducted. The experimental results were obtained using a high-pressure optical strand burner. Steady-state burning rates were determined for a pressure range of 20.8-41.5 MPa and initial propellant temperatures of -30 to +80{sup o}C. For the pressure and temperature ranges tested, the temperature sensitivity was on the order of 1 x 10{sup -3} K{sup -1}. The pressure exponent was found to be a function of the initial propellant temperature and was 0.75 at 25{sup o}C. The activation energy and the pre-exponential factor of the Arrhenius equation are 2.735 kcal/mol and 15.06 cm/s, respectively. The pressure deflagration limit for this propellant was found to be in the range of 8.37-8.72 MPa. During combustion, small condensed-phase spherical particles were ejected from the burning surface. The size of the particles decreased with either increasing the pressure or the initial propellant temperature. For pressures below 41.4 MPa, average particle size was on the order of 900 {mu}m, and at 84.4 MPa, the bead size was much smaller, on the order of 300 {mu}m. A chemical analysis on these particles using both the ESEM and the X-ray diffraction method indicated that the material of the beads was mostly sodium chloride with a small amount of silicon-containing compounds. 6 refs., 17 figs.

  16. Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor - General combustion and ash behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Hao Wu; Peter Glarborg; Flemming Jappe Frandsen; Kim Dam-Johansen; Peter Arendt Jensen; Bo Sander [Technical University of Denmark, Lyngby (Denmark). Department of Chemical and Biochemical Engineering

    2011-05-15

    Co-combustion of a bituminous coal and a solid recovered fuel (SRF) was carried out in an entrained flow reactor, and the influence of additives such as NaCl, PVC, ammonium sulphate, and kaolinite was investigated. The experiments were carried out with SRF shares of 7.9 wt.%, 14.8 wt.% and 25 wt.%, respectively. The effect of additives was evaluated by maintaining the share of secondary fuel (mixture of SRF and additive) at 14.8 wt.%. The results showed that fuel burnout, NO and SO{sub 2} emission decreased with increasing share of SRF. The majority of the additives inhibited the burnout, except for NaCl which seemed to have a promoting effect. The impact of additives on NO emission was mostly insignificant, except for ammonium sulphate which greatly reduced NO emission. For SO{sub 2}, it was found that all of the additives increased the S-retention in ash. Analysis of the bulk composition of fly ash from different experiments indicated that the majority of S and Cl in the fuels were released to gas phase during combustion, whereas the K and Na in the fuels were mainly retained in ash in water insoluble form such as aluminosilicates or silicates. The addition of NaCl, PVC, and ammonium sulphate generally promoted the vaporization of Na and K, resulting in increased formation of water soluble alkalis such as alkali chlorides or sulphates. The vaporization degree of Na and K was found to be correlated during the experiments, suggesting an interaction between the vaporization of Na and K during combustion. By collecting deposits on an air-cooled probe, it was found that the ash deposition propensity in co-combustion decreased with increasing share of SRF. The addition of NaCl and PVC significantly increased the ash deposition propensity, whereas the addition of ammonium sulphate or kaolinite showed a slight reducing effect. 46 refs., 13 figs., 2 tabs.

  17. The mineral phase evolution behaviour in the production of glass-ceramics from municipal solid waste incineration fly ash by melting technology.

    Science.gov (United States)

    Luan, Jingde; Chai, Meiyun; Li, Rundong; Yao, Pengfei; Khan, Agha Saood

    2016-01-01

    High energy consumption was the major obstacle to the widespread application of melting technology in the treatment of municipal solid waste incineration fly ash. Aiming to lower the ash-melting temperature (AMT) for energy-saving, differential scanning calorimetry, X-ray diffraction and the scanning electron microscope were used to investigate the relations between AMT and the mineral evolution. The results indicated that the change of AMT was determined by the types and the contents of mineral crystals. The transition from refractory minerals to fluxing minerals was the key. The transition of the main crystalline phase from pseudowollastonite (Ca3(Si3O9)) to wollastonite (CaSiO3) played a significant role in AMT reduction. A quantum chemistry calculation was carried out to investigate the effect of crystal reaction activity on AMT. In the chemical reaction, the highest occupied molecular orbital and the lowest unoccupied molecular orbital played a more important role than any other orbits. Cations (Ca(2+), Mg(2+), Na(+), K(+)) were apt to enter into the crystal lattice of wollastonite and gehlenite mainly through Si (3), O (1), Si (6), O (10) and Al (2), O (10), and broke the covalent bonds of Si (3)-O (7), Al (1)-O (9) and Al (1)-O (15), respectively. This deconstruction behaviour provided convenient conditions for restructuring and promoted the formation of fluxing minerals. In melts, the excess SiO2 monomers which existed in the form of cristobalite and quartz caused AMT increase.

  18. Leaching behaviour of elements and evaluation of pre-treatment methods for municipal solid waste incinerator residues in column leaching tests.

    Science.gov (United States)

    Kim, Sang-Yul; Tanaka, Nobutoshi; Matsuto, Toshihiko; Tojo, Yasumasa

    2005-06-01

    Two new pre-treatment methods (water-washing/carbonation and carbonation/phosphate stabilization) of municipal solid waste (MSW) incinerator residues were evaluated by column leaching tests under aerobic conditions and anaerobic conditions (which were changed to aerobic conditions after 10 months). A mixture of bottom ash and fly ash (5:1 ratio) was pre-treated using each method. Shredded incombustible residues (SIR) were added to each ash preparation in proportions similar to the ratios present in landfills. For comparison, landfill wastes typical of Japan, namely, a mixture of bottom ash, chelating-pre-treated fly ash, and SIR, were also examined. Leachate samples were collected periodically and analysed over a 15-month period. When compared with chelating pretreatment, both water-washing/carbonation and carbonation/ phosphate stabilization reduced the leaching of Pb, Al, and Cu by about one to two orders of magnitude. Moreover, the initial concentrations of Ca and Pb in leachates from column of water-washing/carbonation were 56-57% and 84-96% less than those from the column of carbonation/phosphate stabilization. Therefore, water-washing/carbonation was considered to be a promising approach to obtain early waste stabilization and to reduce the release of heavy metals to near-negligible levels. The leaching behaviour of elements was also discussed.

  19. Cellular automata to understand the behaviour of beach-dune systems: Application to El Fangar Spit active dune system (Ebro delta, Spain)

    Science.gov (United States)

    Barrio-Parra, Fernando; Rodríguez-Santalla, Inmaculada

    2016-08-01

    Coastal dunes are sedimentary environments characterized by their high dynamism. Their evolution is determined by sedimentary exchanges between the beach-dune subsystems and the dune dynamics itself. Knowledge about these exchanges is important to prioritize management and conservation strategies of these environments. The aim of this work is the inclusion of the aeolian transport rates obtained using a calibrated cellular automaton to estimate the beach-dune sediment exchange rates in a real active dune field at El Fangar Spit (Ebro Delta, Spain). The dune dynamics model is able to estimate average aeolian sediment fluxes. These are used in combination with the observed net sediment budget to obtain a quantitative characterization of the sediment exchange interactions. The methods produce a substantial improvement in the understanding of coastal sedimentary systems that could have major implications in areas where the management and conservation of dune fields are of concern.

  20. Cellular Automata Simulation of Buying Behaviour during Corporation Crisis Formation%企业危机形成中的消费行为的元胞自动机模拟

    Institute of Scientific and Technical Information of China (English)

    刘天卓; 孙伟然; 杨靖

    2011-01-01

    在企业所面临的不同类型的危机中,产品质量危机所占的比重最大。本文从群体行为的角度研究企业产品质量危机的形成机理,利用元胞自动机的定性模拟理论和方法,建立消费者对产品的购买行为的演化模型,通过基于不同的从众系数和演化规则的演化,揭示群体从众行为与企业危机公关与企业产品质量危机的形成之间的关系,并在此基础上提出了基于消费者信任修复理论的管理思路,对现代企业的危机管理有一定的借鉴与指导意义。%In modem society, exigencies happen frequently, and if not handled properly in the incident, the influence that does not digest and relieve the crisis will result in formation. In the different types of crisis the corporation faced, the most proportion is product quality crisis. We research the formation mechanism of enterprise manufacture crisis from the point of group behaviour, utilize the theory and method of qualitative simulation of cellular automata, build the buying behaviour evolution model of customers, by the evolution based different conformity ratio and evolution rule, reveal the relationship between the group behaviour and business crisis public relation and enterprise production crisis, and based on that we propose management thread based on the consumer confidence restore model, which can guide the crisis management for companies.

  1. Comparative studies on cellular behaviour of carnation (Dianthus caryophyllus Linn. cv. Grenadin) grown in vivo and in vitro for early detection of somaclonal variation.

    Science.gov (United States)

    Yaacob, Jamilah Syafawati; Taha, Rosna Mat; Khorasani Esmaeili, Arash

    2013-01-01

    The present study deals with the cytological investigations on the meristematic root cells of carnation (Dianthus caryophyllus Linn.) grown in vivo and in vitro. Cellular parameters including the mitotic index (MI), chromosome count, ploidy level (nuclear DNA content), mean cell and nuclear areas, and cell doubling time (Cdt) were determined from the 2 mm root tip segments of this species. The MI value decreased when cells were transferred from in vivo to in vitro conditions, perhaps due to early adaptations of the cells to the in vitro environment. The mean chromosome number was generally stable (2n = 2x = 30) throughout the 6-month culture period, indicating no occurrence of early somaclonal variation. Following the transfer to the in vitro environment, a significant increase was recorded for mean cell and nuclear areas, from 26.59 ± 0.09  μm² to 35.66 ± 0.10  μm² and 142.90 ± 0.59  μm² to 165.05 ± 0.58  μm², respectively. However, the mean cell and nuclear areas of in vitro grown D. caryophyllus were unstable and fluctuated throughout the tissue culture period, possibly due to organogenesis or rhizogenesis. Ploidy level analysis revealed that D. caryophyllus root cells contained high percentage of polyploid cells when grown in vivo and maintained high throughout the 6-month culture period.

  2. Comparative Studies on Cellular Behaviour of Carnation (Dianthus caryophyllus Linn. cv. Grenadin Grown In Vivo and In Vitro for Early Detection of Somaclonal Variation

    Directory of Open Access Journals (Sweden)

    Jamilah Syafawati Yaacob

    2013-01-01

    Full Text Available The present study deals with the cytological investigations on the meristematic root cells of carnation (Dianthus caryophyllus Linn. grown in vivo and in vitro. Cellular parameters including the mitotic index (MI, chromosome count, ploidy level (nuclear DNA content, mean cell and nuclear areas, and cell doubling time (Cdt were determined from the 2 mm root tip segments of this species. The MI value decreased when cells were transferred from in vivo to in vitro conditions, perhaps due to early adaptations of the cells to the in vitro environment. The mean chromosome number was generally stable (2n=2x=30 throughout the 6-month culture period, indicating no occurrence of early somaclonal variation. Following the transfer to the in vitro environment, a significant increase was recorded for mean cell and nuclear areas, from 26.59 ± 0.09 μm2 to 35.66 ± 0.10 μm2 and 142.90 ± 0.59 μm2 to 165.05 ± 0.58 μm2, respectively. However, the mean cell and nuclear areas of in vitro grown D. caryophyllus were unstable and fluctuated throughout the tissue culture period, possibly due to organogenesis or rhizogenesis. Ploidy level analysis revealed that D. caryophyllus root cells contained high percentage of polyploid cells when grown in vivo and maintained high throughout the 6-month culture period.

  3. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  4. Microstructural architecture developed in the fabrication of solid and open-cellular copper components by additive manufacturing using electron beam melting

    Science.gov (United States)

    Ramirez, Diana Alejandra

    The fabrication of Cu components were first built by additive manufacturing using electron beam melting (EBM) from low-purity, atomized Cu powder containing a high density of Cu2O precipitates leading to a novel example of precipitate-dislocation architecture. These microstructures exhibit cell-like arrays (1-3microm) in the horizontal reference plane perpendicular to the build direction with columnar-like arrays extending from ~12 to >60 microm in length and corresponding spatial dimensions of 1-3 microm. These observations were observed by the use of optical metallography, and scanning and transmission electron microscopy. The hardness measurements were taken both on the atomized powder and the Cu components. The hardness for these architectures ranged from ~HV 83 to 88, in contrast to the original Cu powder microindentation hardness of HV 72 and the commercial Cu base plate hardness of HV 57. These observations were utilized for the fabrication of open-cellular copper structures by additive manufacturing using EBM and illustrated the ability to fabricate some form of controlled microstructural architecture by EBM parameter alteration or optimizing. The fabrication of these structures ranged in densities from 0.73g/cm3 to 6.67g/cm3. These structures correspond to four different articulated mesh arrays. While these components contained some porosity as a consequence of some unmelted regions, the Cu2O precipitates also contributed to a reduced density. Using X-ray Diffraction showed the approximate volume fraction estimated to be ~2%. The addition of precipitates created in the EBM melt scan formed microstructural arrays which contributed to hardening contributing to the strength of mesh struts and foam ligaments. The measurements of relative stiffness versus relative density plots for Cu compared very closely with Ti-6Al-4V open cellular structures - both mesh and foams. The Cu reticulated mesh structures exhibit a slope of n = 2 in contrast to a slope of n = 2

  5. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  6. Using DVS-NIR to assess the water sorption behaviour and stability of a griseofulvin/PVP K30 solid dispersion.

    Science.gov (United States)

    Li, Wanjing; Buckton, Graham

    2015-11-30

    The purpose of this work was to investigate the distribution of water in a physically unstable amorphous solid dispersion (polyvinylpyrrolidone (PVP) and griseofulvin (as a model hydrophobic drug)), both as the sample absorbs water and during prolonged exposure to elevated humidity by use of dynamic vapour sorption combined with near infrared (DVS-NIR). The solid dispersion absorbed much less water than the sum of the water sorption of the individual components. This suggests that griseofulvin hindered PVP from absorbing water through the formation of the solid dispersion. Prolonged storage of the solid dispersion at 75% RH resulted in no significant mass change. Whilst this would usually be interpreted as the absence of crystallization, the NIR spectra demonstrated that crystallization occurred. The reason for the lack of a weight loss was that the expelled water from amorphous griseofulvin was sorbed by PVP, meaning that as the dispersion was broken by the crystallisation of griseofulvin, the PVP was once again free to sorb water (in line with the higher water sorption shown by PVP alone, and in contrast with the lower sorption of water by the solid dispersion). As water is a key factor in the physical stability of amorphous systems, understanding how and where water is absorbed and how this is liable to change is an important advance and offers promise in understanding the mechanism of stabilisation of solid dispersions, and therefore may be useful to predict the stability of new API dispersions.

  7. Determination of nucleoside analog mono-, di-, and tri-phosphates in cellular matrix by solid phase extraction and ultra-sensitive LC-MS/MS detection.

    Science.gov (United States)

    Bushman, Lane R; Kiser, Jennifer J; Rower, Joseph E; Klein, Brandon; Zheng, Jia-Hua; Ray, Michelle L; Anderson, Peter L

    2011-09-10

    An ultra-sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay was developed and validated to facilitate the assessment of clinical pharmacokinetics of nucleotide analogs from lysed intracellular matrix. The method utilized a strong anion exchange isolation of mono-(MP), di-(DP), and tri-phosphates (TP) from intracellular matrix. Each fraction was then dephosphorylated to the parent moiety yielding a molar equivalent to the original nucleotide analog intracellular concentration. The analytical portion of the methodology was optimized in specific nucleoside analog centric modes (i.e. tenofovir (TFV) centric, zidovudine (ZDV) centric), which included desalting/concentration by solid phase extraction and detection by LC-MS/MS. Nucleotide analog MP-, DP-, and TP-determined on the TFV centric mode of analysis include TFV, lamivudine (3TC), and emtricitibine (FTC). The quantifiable linear range for TFV was 2.5-2000 fmol/sample, and that for 3TC/FTC was 0.1 200 pmol/sample. Nucleoside analog MP-, DP-, and TP-determined on the ZDV centric mode of analysis included 3TC and ZDV. The quantifiable linear range for 3TC was 0.1 100 pmol/sample, and 5-2000 fmol/sample for ZDV. Stable labeled isotopic internal standards facilitated accuracy and precision in alternative cell matrices, which supported the intended use of the method for MP, DP, and TP determinations in various cell types. The method was successfully applied to clinical research samples generating novel intracellular information for TFV, FTC, ZDV, and 3TC nucleotides. This document outlines method development, validation, and application to clinical research.

  8. Compression Effects on the Phase Behaviour of Miconazole-Poly (1-Vinylpyrrolidone-Co-Vinyl Acetate) Solid Dispersions-Role of Pressure, Dwell Time, and Preparation Method.

    Science.gov (United States)

    Singh, Abhishek; De Bisschop, Cathérine; Schut, Henk; Van Humbeeck, Jan; Van Den Mooter, Guy

    2015-10-01

    Compression of miconazole-poly (1-vinylpyrrolidone-co-vinyl acetate) (PVPVA64) solid dispersions prepared by spray drying and hot-melt extrusion was performed to gain insights into effect of compression pressure, dwell time, and preparation method on compression-dependent phase behavior. The solid dispersions prepared by spray drying were initially phase-separated showing two glass transition temperature (Tg), whereas the extruded samples showed one single Tg indicating better mixing. Compression caused mixing of spray-dried solid dispersions at high compression pressures and especially high dwell times. The extruded systems showed no statistically significant differences. However, physical mixtures made up from extruded samples containing 20% and 40% of active pharmaceutical ingredient underwent mixing upon compression. Coincidence Doppler measurements were performed to quantify the free volume of PVPVA64 which is a major contributor to the free volume in the solid dispersion matrix. A small but significant difference was found between the open free volume of the pure polymer subjected to varied manufacturing processes. Compression-induced plastic deformation and plastic flow enhances molecular mobility leading to mixing of different domains in solid dispersions. Different manufacturing methods may result in products with similar free volume, thereby showing similar molecular mobility.

  9. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  10. Experimental Simulation of the Radionuclide Behaviour in the Process of Creating Additional Safety Barriers in Solid Radioactive Waste Repositories Containing Irradiated Graphite

    Science.gov (United States)

    Pavliuk, A. O.; Kotlyarevskiy, S. G.; Bespala, E. V.; Zakarova, E. V.; Rodygina, N. I.; Ermolaev, V. M.; Proshin, I. M.; Volkova, A.

    2016-08-01

    Results of the experimental modeling of radionuclide behavior when creating additional safety barriers in solid radioactive waste repositories are presented. The experiments were run on the repository mockup containing solid radioactive waste fragments including irradiated graphite. The repository mockup layout is given; the processes with radionuclides that occur during the barrier creation with a clayey solution and during the following barrier operation are investigated. The results obtained confirm high anti-migration and anti-filtration properties of clay used for the barrier creation even under the long-term excessive water saturation of rocks confining the repository.

  11. Kinetics behaviour of metastable equiatomic Cu–Fe solid solution as function of the number of collisions induced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Contini, A., E-mail: alessandro.contini@hotmail.com [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, via Vienna 2, 07100 Sassari (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, 09123 Cagliari (Italy); Garroni, S.; Mulas, G.; Enzo, S. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, via Vienna 2, 07100 Sassari (Italy)

    2014-12-05

    Graphical abstract: - Highlights: • Cu–Fe powders were studied as a function of the number of hits during MA. • An impulsive model describes the kinetics curves of solid solution formation. • The kinetic curve indicates that powders must undergo 6 critical events to transform. - Abstract: We have addressed a new study by mechanical alloying on the nominally immiscible Cu{sub 50}Fe{sub 50} system with the aim of relating the solid state transformation process, with formation of a disordered unstable solid solution having the face centered cubic habit, to parameters reflecting the impulsive, discontinuous nature of the process. The milling set-up, tools and powder were adjusted in order to ensure completely anelastic hits. Phase analysis, structure and microstructure parameters of such powder system have been followed accurately in the course of the kinetics by X-ray Diffraction using the Rietveld method. The experimental kinetics data points of the amount of transformed solid solution show a typical sigmoidal behavior. It was assumed that dissolution only occurs in the volumes of material that have undergone the necessary critical loading conditions, which is accounted by a discrete series expansion. The mass fraction effectively processed at each collision can be regarded as an apparent rate constant for the microstructural refinement and phase transformation processes. Analysis of model curves fitting the experimental data suggests that it takes up an average of 6 impacts of coupled powder particles to drive the system to the new unstable nano-crystalline state.

  12. Proton glass behaviour in a solid solution of gamma-irradiated deuterated betaine phosphate sub 0 sub . sub 1 sub 5 betaine phosphite sub 0 sub . sub 8 sub 5

    CERN Document Server

    Banys, J; Klimm, C; Voelkel, G; Kloepperpieper, A

    1997-01-01

    Measurements of the dielectric permittivity are reported for a deuterated solid solution of gamma-irradiated antiferroelectric (betainephosphate) sub 0 sub . sub 1 sub 5 ferroelectric (betainephosphite) sub 0 sub . sub 8 sub 5 at frequencies 20 H sub Z behaviour with an estimated glass temperature of 55.4 K. (author). Letter-to-the-editor

  13. Incorporation Behaviour of Arsenic and Phosphorus in GaAsP/GaAs Grown by Solid Source Molecular Beam Epitaxy with a GaP Decomposition Source

    Institute of Scientific and Technical Information of China (English)

    WU Shu-Dong; GUO Li-Wei; WANG Wen-Xin; LI Zhi-Hua; NIU Ping-Juan; HUANG Qi; ZHOU Jun-Ming

    2005-01-01

    @@ The incorporation behaviour of arsenic and phosphorus in the GaAsP ternary alloy under phosphorus-rich conditions is studied based on the incorporation coeffcient model and the growth diffusion model combined with the alloy composition data obtained by high resolution x-ray diffraction analysis.It is found that As adatoms have longer surface lifetime and longer migration length than those of P adatoms, which leads to an arsenic incorporation efficiency much higher than that of phosphorous.With the increase of arsenic flux, the surface lifetime of arsenic adatoms decreases due to the competition of As adatoms.The detailed analysis and discussion are given here.

  14. Assessing the presence of enrofloxacin and ciprofloxacin in piggery wastewater and their adsorption behaviour onto solid materials, with a newly developed chromatographic method.

    Science.gov (United States)

    Parpounas, Andreas; Litskas, Vassilis; Hapeshi, Evroula; Michael, Costas; Fatta-Kassinos, Despo

    2017-08-25

    Veterinary antibiotics could enter the environment after the application of manure or farm wastewater on soil as fertilizer. In this study, a UPLC-MS/MS analytical method was developed and validated for the simultaneous determination of enrofloxacin (ENR) and ciprofloxacin (CIP) at environmental relevant concentrations in piggery wastewater, piggery wastewater solids, agricultural soil and ground water with good performance characteristics. The method recovery for ENR and CIP was 94.2 and 89.9% in the filtered piggery wastewater, 81.3 and 82% in the wastewater solid material, 78.1 and 76.8% in the soil and 95.6 and 97.3% in the ground water. The Limit of Detection (LOD) and Limit of Quantification (LOQ) for ENR were 21 and 64 ng L(-1) and for CIP was 18 and 54 ng L(-1), respectively. The method was implemented to monitor ENR and CIP in the wastewater of a piggery facility in Cyprus which applied anaerobic treatment before the final disposal of the reclaimed water. The highest antibiotic concentrations were measured in the wastewater samples collected from the nursery, where ENR is continuously used, with average concentration 31.4 μg L(-1) for ENR and 16.0 μg L(-1) for CIP. After the anaerobic digester, the two antibiotics were found only on the solid matter of the treated wastewater with an average concentration of 1.7 μg kg(-1) for ENR and 1.0 μg kg(-1) for CIP. The antibiotics adsorption at pH = 7 on clay soil, quartz sand and on solid matter isolated from the piggery wastewater was found to be higher than 95% for all solid materials. The concentration of the antibiotics in soil samples taken from a field where reclaimed piggery wastewater was applied for 10 years and in samples of groundwater from a nearby well was found for all samples below the LOD.

  15. Contribution to the study of the behaviour of solid particles in a confined turbulent flow using direct numerical simulation; Contribution a l'etude du comportement de particules solides en ecoulement turbulent confine par simulation numerique directe

    Energy Technology Data Exchange (ETDEWEB)

    Rambaud, P.

    2001-11-01

    The theme of this numerical thesis is on the behavior of solid particles embedded in a non-homogeneous and non-isotropic turbulent gas flow as the one tacking place in a plane channel. The turbulence is generated through the direct numerical simulation of Navier-Stokes equations discretized by formally second order in time and space finite difference operators. This Eulerian vision of the incompressible gas flow is completed by a Lagrangian formulation allowing to follow solid particles. In this formulation, the considered forces are the non-linear drag and the Saffman lift both corrected for wall effects. Furthermore, depending on the test cases studied, particle bouncing forces on the wall, gravity or electrostatic forces are taken into account. A three-dimensional Hermitian interpolation highlight the special care spend on the determination of the fluid velocity at the solid particle location. The first code application is dedicated to solid particles dispersion inside an horizontal channel, or in a channel operated in a weightlessness state. The huge amount of data from the Lagrangian tracking is reduced to the integral times of the turbulence seen by the solid particles on their trajectories. Those times are crucial in Lagrangian methods associated with a low numerical cost compared with the ones used in the present study. Among those methods, the one based on Langevin type equations have the best potential to handle industrial type problems. Nevertheless, this method needs to rebuild the fluid velocity fluctuations seen by the solid particles on their trajectories. This technic is able to reproduce the crossing trajectory effect, the inertial effect and the continuity effect, only if the integral times of the turbulence seen are known. Till now, those times were known thanks to a semi-empirical correlation from direct numerical simulation in homogeneous and isotropic turbulence (Wang and Stock 1993). However, although these conditions, this correlation was

  16. Lamellar crystalline self-assembly behaviour and solid lipid nanoparticles of a palmityl prodrug analogue of Capecitabine—A chemotherapy agent

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Xiaojuan; Moghaddam, Minoo J.; Sagnella, Sharon M.; Conn, Charlotte E.; Danon, Stephen J.; Waddington, Lynne J.; Drummond, Calum J. [CSIRO/MSE

    2014-09-24

    An amphiphile prodrug, 5'-deoxy-5-fluoro-N4-(palmityloxycarbonyl) cytidine or 5'-deoxy-5-fluoro-N4-(hexadecanaloxycarbonyl) cytidine (5-FCPal), consisting of the same head group as the commercially available chemotherapeutic agent Capecitabine, linked to a palmityl hydrocarbon chain via a carbamate bond is reported. Thermal analysis of this prodrug indicates that it melts at ~115 °C followed quickly by degradation beginning at ~120 °C. The neat solid 5-FCPal amphiphile acquires a lamellar crystalline arrangement with a d-spacing of 28.6 ± 0.3 Å, indicating interdigitation of the hydrocarbon chains. Under aqueous conditions, solid 5-FCPal is non-swelling and no lyotropic liquid crystalline phase formation is observed. In order to assess the in vitro toxicity and in vivo efficacy in colloidal form, solid lipid nanoparticles (SLNs) with an average size of ~700 nm were produced via high pressure homogenization. The in vitro toxicity of the 5-FCPal SLNs against several different cancer and normal cell types was assessed over a 48 h period, and IC50 values were comparable to those observed for Capecitabine. The in vivo efficacy of the 5-FCPal SLNs was then assessed against the highly aggressive mouse 4T1 breast cancer model. To do so, the prodrug SLNs were administered orally at 3 different dosages (0.1, 0.25, 0.5 mmol/mouse/day) and compared to Capecitabine delivered at the same dosages. After 21 days of receiving the treatments, the 0.5 mmol dose of 5-FCPal exhibited the smallest average tumour volume. Since 5-FCPal is activated in a similar manner to Capecitabine via a 3 step enzymatic pathway with the final step occurring preferentially at the tumour site, formulation of the prodrug into SLNs combines the advantage of selective, localized activation with the sustained release properties of nanostructured amphiphile self-assembly and multiple payload materials thereby potentially creating a more effective anticancer agent.

  17. Behaviour of the elements introduced with the fuels in their distribution and immobilization between the coal-petroleum coke IGCC solid products

    Energy Technology Data Exchange (ETDEWEB)

    Ramon Alvarez-Rodriguez; Carmen Clemente-Jul; Juan A. Martin-Rubi [Technical University of Madrid (UPM), Madrid (Spain). Mining School

    2007-09-15

    In this research on the solid products of the Elcogas IGCC plant (Puertollano, Spain) the influence of the two fuels, coal and pet coke, on the composition of the fly ashes and slag is demonstrated and how the majority of the elements are provided by the coal and only some as V, Ni and Mo are provided by the pet coke. The different nature of slag and fly ashes is highlighted and how the different elements are distributed between them that in general follow the indications of the mathematical models. The passage of the elements into gaseous phase is calculated. The fly ashes are some products of very fine granulometry that present problems of solubilization of a series of elements and therefore of deposition. Their inertization has been investigated by calcination at 1000{sup o}C and with additives. Some good results have been obtained. 20 refs., 14 figs., 4 tabs.

  18. Application of a stochastic modelling framework to characterize the influence of different oxide scales on the solid particle erosion behaviour of boiler grade steel

    Indian Academy of Sciences (India)

    S K Das

    2011-08-01

    An earlier developed stochastic model has been applied to describe the relative rate of material loss from the steel surface subjected to simultaneous action of high temperature oxidation involving multiple oxides and mechanical erosion. Different oxide scale growths, namely, nickel, iron and chromium have been treated deterministically and erosion is described using a literature based probabilistic framework. Oxidation is described with a power law (parabolic) approach to quantify the rate of growth of all the three oxide scales. In consonance with the published model, erosion is treated using a probabilistic methodology as spatially random phenomena on the oxide surface. The concept of ‘erosion footprint’ has been incorporated in the present model to characterize the erosion-induced damage on the steel surface. The model has been applied to predict the relative material loss as a function of time resulted from erosion–oxidation interaction pertaining to nickel, iron and chromium oxides in dimensionless form. This investigation is expected to provide a quantitative understanding of relative material loss due to solid particle erosion for oxide scales, (composed of multiple oxides) formed on the steel components of coal-fired boilers.

  19. Determination of biocides and pesticides by on-line solid phase extraction coupled with mass spectrometry and their behaviour in wastewater and surface water

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Heinz; Jaus, Sylvia; Hanke, Irene; Lueck, Alfred; Hollender, Juliane [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland); Alder, Alfredo C., E-mail: alfredo.alder@eawag.c [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600 Duebendorf (Switzerland)

    2010-10-15

    This study focused on the input of hydrophilic biocides into the aquatic environment and on the efficiency of their removal in conventional wastewater treatment by a mass flux analysis. A fully automated method consisting of on-line solid phase extraction coupled to LC-ESI-MS/MS was developed and validated for the simultaneous trace determination of different biocidal compounds (1,2-benzisothiazoline-3-one (BIT), 3-Iodo-2-propynylbutyl-carbamate (IPBC), irgarol 1051 and 2-N-octyl-4-isothiazolinone (octhilinone, OIT), carbendazim, diazinon, diuron, isoproturon, mecoprop, terbutryn and terbutylazine) and pharmaceuticals (diclofenac and sulfamethoxazole) in wastewater and surface water. In the tertiary effluent, the highest average concentrations were determined for mecoprop (1010 ng/L) which was at comparable levels as the pharmaceuticals diclofenac (690 ng/L) and sulfamethoxazole (140 ng/L) but 1-2 orders of magnitude higher than the other biocidal compounds. Average eliminations for all compounds were usually below 50%. During rain events, increased residual amounts of biocidal contaminants are discharged to receiving surface waters. - Incomplete removal of biocides and pesticides during wastewater treatment.

  20. Impact on knowledge and behaviour of the general population of two different methods of solid waste management: An explorative cross-sectional study.

    Science.gov (United States)

    Del Cimmuto, Angela; Mannocci, Alice; Ribatti, Domenico; Boccia, Antonio; La Torre, Giuseppe

    2014-06-01

    The objectives of the present study were to evaluate knowledge among general population about the risks factors of waste management, to estimate the feeling of anxiety concerning the waste, and to compare knowledge of two different methods for collecting municipal solid waste (MSW): a street separate collection system and a door-to-door separate collection system. A cross-sectional study was performed, administering an anonymous questionnaire to 180 inhabitants in Aprilia, Latium, Italy. The study sample consisted of 183 citizens: 64 in the intervention group and 119 in the control group. The intervention was represented by a campaign of door-to-door collection. The correct implementation of separate collection of waste was 87.5% in the intervention group and 63% in the control group (pwaste collection was door-to-door (p=0.013); a high difference concerning the quality of information was found (pmanagement of waste and household waste. The door-to-door collection was appreciated and preferred by both groups. The adoption of a door-to-door scheme seems to be a winning option mostly because it is supported by an information and education system for the citizens.

  1. Partition chromatography separation using trilaurylamine adsorbed on a solid support. Behaviour of the uranyl ion; Separations par chromatographie de partage au moyen de trilaurylamine adsorbee sur support solide comportement de l'ion uranyle

    Energy Technology Data Exchange (ETDEWEB)

    Petit-Bromet, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-07-01

    The extractive phase is made up of a TLA solution in cyclohexanol adsorbed on a solid poly-trifluorochloroethylene support (sold commercially as voltalef or KEL-F). The mixture obtained is homogeneous and can be used for partition chromatography. For a solution of hydrochloric acid stronger than 1 M, the amine is quantitatively in the form of the chlorohydrate. The partition curve for U(VI) between the 2 N hydrochloric acid aqueous phase and the organic TLA phase has two steps which can be explained by assuming that two complexes exist in the organic phase. The equilibrium constants for extraction have been determined. The homogeneity of the voltalef-amine mixture has made it possible to build up a column with reproducible characteristics. Under the operational conditions adopted, the height of the equivalent theoretical plate is about 3 mm. A plot of all the curves giving the variations in the partition function of U(VI), Fe(III), Cu(II), Sr(II) and Cs(I) as a function of the hydrochloric acid concentration makes it possible to predict the conditions under which these elements may be separated. [French] La phase extractive est constituee d'une solution de TLA dans le cyclohexanol adsorbe sur un support solide de polytrifluorochloroethylene (commercialise sous le nom de voltalef ou KEL-F). Le melange obtenu est homogene et peut etre utilise en chromatographie de partage. Pour une concentration d'acide chlorhydrique en solution superieure a 1 M, l'amine est quantitativement sous forme de chlorhydrate. La courbe de partage de U(VI) entre la phase aqueuse d'acide chlorhydrique 2 N et la phase organique de TLA presente deux paliers que l'on peut interpreter en admettant l'existence de deux complexes en phase organique. Les constantes des equilibres d'extraction ont ete determinees. L'homogeneite du melange voltalef-amine a permis de constituer une colonne.dont les caracteristiques sont reproductibles. Dans les conditions de

  2. Aggressive behaviour of solid-pseudopapillary tumor of the pancreas in adults:A case report and review of the literature

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Solid-pseudopapillary tumor (SPT) is a rare neoplasm of the pancreas that usually occurs in young females.It is generally considered a low-grade malignant tumor that can remain asymptomatic for several years.The occurrence of infiltrating varieties of 5PT is around 10%-15%.Between 1986 and 2006,282 cystic tumors of the pancreas were observed.Among them a SPT was diagnosed in 8 patients (2.8%) with only one infiltrating variety.This was diagnosed in a 49-year-old female 13 years after the sonographic evidence of a small pancreatic cystic lesion interpreted as a pseudocyst.The tumor invaded a long segment of the portalmesenteric vein confluence,and was removed with a total pancreatectomy,resection of the portal vein and reconstruction with the internal jugular vein.Histological examination confirmed the R-0 resection of the primary SPT,although a vascular invasion was demonstrated.The postoperative course was uneventful,but 32 mo after surgery the patient experienced diffuse liver metastases.Chemotherapy with different drugs was started.The patient is alive and symptom-free,with stable disease,75 mo after surgery.Twenty-five patients with invasion of the portal vein and/or of mesenteric vessels were retrieved from the literature,16 recent patients with tumor relapse after potentially curative resection were also retrieved.The best treatment remains a radical resection whenever possible,even in locally advanced or metastatic disease.The role of chemotherapy,and/or radiotherapy,is still to be defined.

  3. Suicidal behaviour

    NARCIS (Netherlands)

    Neeleman, J

    2001-01-01

    -Prevention of suicidal behaviour remains difficult, despite increasing knowledge of its determinants. Health service efforts hardly affect suicide rates. -Recent shifts in the epidemiology of suicidal behaviour are rising rates among the young and increasing use of violent methods. these can be lin

  4. Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    C. Lievens; J. Yperman; J. Vangronsveld; R. Carleer [Hasselt University, Diepenbeek (Belgium). Laboratory of Applied Chemistry

    2008-08-15

    Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (623, 673, 773 and 873 K) and the type of solid heat carrier (sand and fumed silica) on the distribution of the heavy metals in birch and sunflower pyrolysis fractions are studied. The goal of the set-up is 'concentrating' heavy metals in the ash/char fraction after thermal treatment, preventing them to be released in the condensable and/or volatile fractions. The knowledge of the behaviour of heavy metals affects directly future applications and valorisation of the pyrolysis products and thus contaminated biomass. They are indispensable for making and selecting the proper thermal conditions for their maximum recovery. In view of the future valorisation of these biomasses, the amounts of the pyrolysis fractions and the calorific values of the obtained liquid pyrolysis products, as a function of the pyrolysis temperature, are determined. 46 refs., 8 figs., 4 tabs.

  5. Behavioural Modernity

    OpenAIRE

    McLean, Laura

    2015-01-01

    Behavioural Modernity explores the changing politics of representation and ethics of care in curatorial practice, necessitated by an increasing blurring of boundaries between the human, the technological, and the planetary.

  6. Sickness Behaviour:

    African Journals Online (AJOL)

    adaptive function for hyperthermia and ... on immunity. However ... infectious disorders probably lies in the ... nervous system, and thus behaviour, .... Fever: Basic ... system. In Ader R, Felten DL,. Cohen N, editors. Psychoneuro- immunology.

  7. CELLULAR AUTOMATA AND COMPUTER GRAPHICS

    Directory of Open Access Journals (Sweden)

    Şen ÇAKIR

    1999-01-01

    Full Text Available Cellular Automata (CA are simple mathematical systems which provide models for a variety of physical processes. They show how minute changes and simple rules lead to enormous changes in the behaviour of a system. They can also be used as computer graphics tools to produce a rich reservoir of interesting figures. In recent years, CA have attracked the attention of many scientists. Today, CA are used in many fields from ecology to image processing. In this paper, it is shown that a large number of complex and interesting patterns can be created with relatively simple CA rules.

  8. Glass transitions in the cellular Potts model

    Science.gov (United States)

    Chiang, M.; Marenduzzo, D.

    2016-10-01

    We study the dynamical transition between a fluid-like and a solid-like phase in a confluent cell monolayer, by using the cellular Potts model and computer simulations. We map out the phase diagram as a function of interfacial tension and of cell motility. While in the fluid phase there is normal diffusion, in the solid phase we observe sub-diffusion, very slow relaxation, and ageing, thereby strongly suggesting that this phase is glassy. Our results complement previous theoretical work within the vertex model and show that the cellular Potts model can account for the experimentally observed glassy dynamics of some biological tissues.

  9. Combustion Behaviour of Advanced Solid Propellants.

    Directory of Open Access Journals (Sweden)

    S. N. Asthana

    1993-07-01

    Full Text Available The study reports the effect of incorporation of Al and ammonium perchlorate (AP individually and in combination with each other on combustion pattern and specific impulse (Isp of minimum signature propellants. Incorporation of Al obviates the combustion instability problems; however, it has marginal effect on burning rates. The composition containing AP and zirconium silicate combination gives superior performance; however, its Isp is considerably lower than the composition incorporating 9 per cent AP. A combination of 6 per cent Al gave 20 per cent enhancement in burning rate and 12 s increase in Isp as compared to purely nitramine-based composition, cal-val results also reveal increase in energy output on incorporating AP and Al. Hot stage microscopic and propellant combustion studies indicate occurrence of intense decomposition reaction in case of AP-based compositions.

  10. Consumer behaviours

    DEFF Research Database (Denmark)

    Grønhøj, Alice

    2016-01-01

    Energy-saving programmes are increasingly targeted at children to encourage household energy conservation. A study involving the assignment of energy-saving interventions to Girl Scouts shows that a child-focused intervention can improve energy-saving behaviours among children and their parents....

  11. Comportamento celular e resposta antioxidante diferenciados de Saccharomyces cerevisiae e de Saccharomyces chevalieri ao metavanadato de amónio Different cellular behaviour and antioxidant response of Saccharomyces cerevisiae and Saccharomyces chevalieri growing in presence of ammonium metavanadate

    Directory of Open Access Journals (Sweden)

    R. Ferreira

    2007-01-01

    conditions. In the cellular environment of aerobic organisms naturally reactive oxygen species (ROS occurs as by-products of mitochondrial respiration. The higher reactivity of these chemical species could cause molecular damages that in several cases induce cellular death. In common physiological conditions or as response to oxidative stress, the cell can generate adapted responses which involve antioxidants mechanisms as glutathione reductase (GR; EC 1.6.4.2 and catalase T (CAT T; EC 1.11.1.6 and A (CAT A; EC 1.11.1.6 enzymes. Vanadium, a heavy metal present in several pesticides could generate ROS changing the intracellular redox state and cause deleterious effects in yeasts exposed to higher levels of this element. The main objective of this work was to compare the effects of ammonium metavanadate (NH4VO3, a pentavalent salt of vanadium on cellular viability and GR, CAT T and CAT A activities of wine yeast Saccharomyces cerevisiae UE-ME3 and Saccharomyces chevalieri UE-ME1. The results obtained show that S. chevalieri UE-ME1 has lower tolerance to NH4VO3 than S. cerevisiae UE-ME3, since S. chevalieri cultures do not survive to concentration values of ammonium metavanadate higher than 7,5 mM, whereas S. cerevisiae cells are still viable in the presence of 75 mM. S. chevalieri has an enzymatic activity lower than S. cerevisiae, although for both yeast species NH4VO3 could behave as oxidative stress inductor, causing a significant decrease of GR activity (P<0,01 and a significant increase of CAT A activity (P<0,01. The results show also an increase of CAT T activity in both yeast species, which can be interpreted as a protective response to oxidative stress. Differences on response to amonium metavanadate by both species of Saccharomyces could be partially justified by more efficient antioxidant systems in S. cerevisiae UE-ME3.

  12. Generic behaviours in impact fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Sator, N.; Mechkov, S.; Sausset, F. [Paris-6 Univ. Pierre et Marie Curie, Lab. de Physique Theorique de la Matiere Condensee, UMR CNRS 7600, 75 - Paris (France); Mechkov, S. [Ecole Normale Superieure, Lab. de Physique Statistique, 75 - Paris (France)

    2008-02-15

    From atomic nuclei to supernovae, including plates and rocks, every cohesive system can be broken into fragments, provided that the deposited energy is sufficiently large compared to its cohesive energy. We present a simple numerical model for investigating the general properties of fragmentation. By use of molecular dynamics simulations, we study the impact fragmentation of a solid disk of interacting particles with a wall. Regardless of the particular form of the interaction potential, the fragment size distribution exhibits a power law behaviour with an exponent that increases logarithmically with the energy deposited in the system, in agreement with experiments. We expect this behaviour to be generic in fragmentation phenomena. (authors)

  13. Modelling Behaviour

    DEFF Research Database (Denmark)

    2015-01-01

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while....... The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015....

  14. Additional force field in cooling process of cellular Al alloy

    Institute of Scientific and Technical Information of China (English)

    郑明军; 何德坪; 戴戈

    2002-01-01

    The foaming process of Al alloy is similar to that of Al, but there is a solid-liquid state zone in the solidification process of cellular Al alloy which does not exist in the case of Al. In the unidirectional solidification of cellular Al alloy, the proportion of the solid phase gradually reduces from the solid front to the liquid front. This will introduce a force and result in a serious quick shrinkage. By the mathematic and physical mode, the solidification of the cellular Al alloy is studied. The data measured by experiment are close to the result calculated by the mode. This kind of shrinkage can be solved by suitable cooling method in appropriate growth stage. The compressive strength of the cellular Al alloy made by this way is 40% higher than that of cellular Al.

  15. Flat Cellular (UMTS) Networks

    NARCIS (Netherlands)

    Bosch, H.G.P.; Samuel, L.G.; Mullender, S.J.; Polakos, P.; Rittenhouse, G.

    2007-01-01

    Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective i

  16. Benchmark study between FIDAP and a cellular automata code

    Science.gov (United States)

    Akau, R. L.; Stockman, H. W.

    A fluid flow benchmark exercise was conducted to compare results between a cellular automata code and FIDAP. Cellular automata codes are free from gridding constraints, and are generally used to model slow (Reynolds number approximately 1) flows around complex solid obstacles. However, the accuracy of cellular automata codes at higher Reynolds numbers, where inertial terms are significant, is not well-documented. In order to validate the cellular automata code, two fluids problems were investigated. For both problems, flow was assumed to be laminar, two-dimensional, isothermal, incompressible and periodic. Results showed that the cellular automata code simulated the overall behavior of the flow field.

  17. PHYSICAL MODEL FOR THE ENGINEERING ANALYSIS OF THE THERMOELASTICLTY OF SOLID BODIES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The thermal behaviour of the solids under elastic deformations is analysed in order to obtain a model which combines the molecular dynamics results with the global thermal behaviour of the solids under elastic t ransformations.The result obtained consists of the introduction of the thermal behaviour in the ParrinelloRahman model,obtaining the thermal molecular dynamic model useful in the analysis of the thermoelastic behaviour of solids.

  18. Mesophase behaviour of polyhedral particles

    KAUST Repository

    Agarwal, Umang

    2011-02-13

    Translational and orientational excluded-volume fields encoded in particles with anisotropic shapes can lead to purely entropy-driven assembly of morphologies with specific order and symmetry. To elucidate this complex correlation, we carried out detailed Monte Carlo simulations of six convex space-filling polyhedrons, namely, truncated octahedrons, rhombic dodecahedrons, hexagonal prisms, cubes, gyrobifastigiums and triangular prisms. Simulations predict the formation of various new liquid-crystalline and plastic-crystalline phases at intermediate volume fractions. By correlating these findings with particle anisotropy and rotational symmetry, simple guidelines for predicting phase behaviour of polyhedral particles are proposed: high rotational symmetry is in general conducive to mesophase formation, with low anisotropy favouring plastic-solid behaviour and intermediate anisotropy (or high uniaxial anisotropy) favouring liquid-crystalline behaviour. It is also found that dynamical disorder is crucial in defining mesophase behaviour, and that the apparent kinetic barrier for the liquid-mesophase transition is much lower for liquid crystals (orientational order) than for plastic solids (translational order). © 2011 Macmillan Publishers Limited. All rights reserved.

  19. Thermomechanical characterisation of cellular rubber

    Science.gov (United States)

    Seibert, H.; Scheffer, T.; Diebels, S.

    2016-09-01

    This contribution discusses an experimental possibility to characterise a cellular rubber in terms of the influence of multiaxiality, rate dependency under environmental temperature and its behaviour under hydrostatic pressure. In this context, a mixed open and closed cell rubber based on an ethylene propylene diene monomer is investigated exemplarily. The present article intends to give a general idea of the characterisation method and the considerable effects of this special type of material. The main focus lies on the experimental procedure and the used testing devices in combination with the analysis methods such as true three-dimensional digital image correlation. The structural compressibility is taken into account by an approach for a material model using the Theory of Porous Media with additional temperature dependence.

  20. Durability of Solid Oxide Cells

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Hauch, Anne; Hjelm, Johan

    2011-01-01

    In recent years extended focus has been placed on monitoring and understanding degradation mechanisms in both solid oxide fuel cells and solid oxide electrolysis cells. The time-consuming nature of degradation experiments and the disparate conclusions from experiment reproductions indicates...... behaviour and mechanisms are discussed. For ease of navigation, the review is separated into the various cell components – fuel electrode, electrolyte and oxygen electrode. Finally, nano-particle impregnate stability is discussed....

  1. Modelling Behaviour

    DEFF Research Database (Denmark)

    2015-01-01

    This book reflects and expands on the current trend in the building industry to understand, simulate and ultimately design buildings by taking into consideration the interlinked elements and forces that act on them. This approach overcomes the traditional, exclusive focus on building tasks, while....... The chapter authors were invited speakers at the 5th Symposium "Modelling Behaviour", which took place at the CITA in Copenhagen in September 2015....... posing new challenges in all areas of the industry from material and structural to the urban scale. Contributions from invited experts, papers and case studies provide the reader with a comprehensive overview of the field, as well as perspectives from related disciplines, such as computer science...

  2. Hydrodynamic Behaviour of a Gas-Solid Air-loop Stripper%气升式气-固环流汽提器的流体力学行为

    Institute of Scientific and Technical Information of China (English)

    刘梦溪; 卢春喜; 时铭显

    2004-01-01

    In this paper, the principles of airlift loop reactor in gas-liquid and gas-liquid-solid systems are extended to gas-solid system. The models on bed average voidage in draft tube and the particle circulation velocity in a gas-solid loop reactor are deduced. The experiments are also conducted on a φ600mm×7000mm reactor. The catalyst voidage and catalyst circulation velocity are measured at different radial and axial positions in draft tube and annulus, respectively. The experimental data are analyzed systemically and represented satisfactorily by the proposed models.

  3. A study on consumer switching behaviour in cellular service provider

    OpenAIRE

    M. Sathish; K.J.Naveen; V.Jeevanantham

    2011-01-01

    Indian mobile market is a fastest growing market and is forecasted to reach 868.47 million users by 2013. India has seen rapid increase in number of players which caused the tariff rates to hit an all time low. This allowed the players to target the low income population increasing the market share. The availability of number of subscriber options for consumers and varied tariff rates of each player, lead the consumers to switch the service providers. The objectives of the study are to find t...

  4. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  5. Directional Dynamics along Arbitrary Curves in Cellular Automata

    CERN Document Server

    Delacourt, Martin; Sablik, Mathieu; Theyssier, Guillaume

    2010-01-01

    This paper studies directional dynamics in cellular automata, a formalism previously introduced by the third author. The central idea is to study the dynamical behaviour of a cellular automaton through the conjoint action of its global rule (temporal action) and the shift map (spacial action): qualitative behaviours inherited from topological dynamics (equicontinuity, sensitivity, expansivity) are thus considered along arbitrary curves in space-time. The main contributions of the paper concern equicontinuous dynamics which can be connected to the notion of consequences of a word. We show that there is a cellular automaton with an equicontinuous dynamics along a parabola, but which is sensitive along any linear direction. We also show that real numbers that occur as the slope of a limit linear direction with equicontinuous dynamics in some cellular automaton are exactly the computably enumerable numbers.

  6. Experimental Ultrasound Transmission through Fluid-Solid and Air-Solid Phononic Plates

    Directory of Open Access Journals (Sweden)

    Vicente Gómez-Lozano

    2016-06-01

    Full Text Available Underwater ultrasonic transmissions for fluid-solid and air-solid phononic brass plates are reported in this work. Although the structure is roughly the same, experimental results show very different behaviour between fluid-solid and air-solid phononic plates, due to most of the properties of the fluid-solid perforated plates rely on Fabry-Perot resonances, Wood anomalies and Lamb modes. In air-solid phononic plates Fabry-Perot resonance is highly attenuated due to impedances difference between air and water, and therefore some transmission modes are now distinguishable due to surface modes coupling.

  7. Solid propellants.

    Science.gov (United States)

    Marsh, H. E., Jr.; Hutchison, J. J.

    1972-01-01

    The basic principles underlying propulsion by rocket motor are examined together with the configuration of a solid propellant motor. Solid propellants and their preparation are discussed, giving attention to homogeneous propellants, composite propellants, energetic considerations in choosing a solid propellant, the processing of composite propellants, and some examples of new developments. The performance of solid propellants is investigated, taking into account characteristics velocity, the specific impulse, and performance calculations. Aspects of propellant development considered include nonperformance requirements for solid propellants, the approach to development, propellant mechanical properties, and future trends.

  8. Light weight cellular structures based on aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, O. [Indian Inst. of Tech., Kanpur (India); Embury, J.D.; Sinclair, C. [McMaster Univ., Hamilton, ON (Canada); Sang, H. [Queen`s Univ., Kingston, ON (Canada); Silvetti, P. [Cordoba Univ. Nacional (Argentina). Facultad de Ciencias Exactas, Fisicas y Naturales

    1997-02-01

    An interesting form of lightweight material which has emerged in the past 2 decades is metallic foam. This paper deals with the basic concepts of making metallic foams and a detailed study of foams produced from Al-SiC. In addition, some aspects of cellular solids based on honeycomb structures are outlined including the concept of producing both two-phase foams and foams with composite walls.

  9. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  10. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  11. Epigenetics and Cellular Metabolism

    OpenAIRE

    Wenyi Xu; Fengzhong Wang; Zhongsheng Yu; Fengjiao Xin

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the proce...

  12. Nanostructured cellular networks.

    Science.gov (United States)

    Moriarty, P; Taylor, M D R; Brust, M

    2002-12-01

    Au nanocrystals spin-coated onto silicon from toluene form cellular networks. A quantitative statistical crystallography analysis shows that intercellular correlations drive the networks far from statistical equilibrium. Spin-coating from hexane does not produce cellular structure, yet a strong correlation is retained in the positions of nanocrystal aggregates. Mechanisms based on Marangoni convection alone cannot account for the variety of patterns observed, and we argue that spinodal decomposition plays an important role in foam formation.

  13. Solid lubricants

    Science.gov (United States)

    Sliney, Harold E.

    1993-01-01

    The state of knowledge of solid lubricants is reviewed. The results of research on solid lubricants from the 1940's to the present are presented from a historical perspective. Emphasis is placed largely, but not exclusively, on work performed at NASA Lewis Research Center with a natural focus on aerospace applications. However, because of the generic nature of the research, the information presented in this review is applicable to most areas where solid lubricant technology is useful.

  14. Solid Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Supported by a generous quantity of full-color illustrations and interesting sidebars, Solid Matter introduces the basic characteristics and properties of solid matter. It briefly describes the cosmic connection of the elements, leading readers through several key events in human pre-history that resulted in more advanced uses of matter in the solid state. Chapters include:. -Solid Matter: An Initial Perspective. -Physical Behavior of Matter. -The Gravity of Matter. -Fundamentals of Materials Science. -Rocks and Minerals. -Metals. -Building Materials. -Carbon Earth's Most Versatile Element. -S

  15. Cellular nanotechnology: making biological interfaces smarter.

    Science.gov (United States)

    Mendes, Paula M

    2013-12-21

    Recently, there has been an outburst of research on engineered cell-material interfaces driven by nanotechnology and its tools and techniques. This tutorial review begins by providing a brief introduction to nanostructured materials, followed by an overview of the wealth of nanoscale fabrication and analysis tools available for their development. This background serves as the basis for a discussion of early breakthroughs and recent key developments in the endeavour to develop nanostructured materials as smart interfaces for fundamental cellular studies, tissue engineering and regenerative medicine. The review covers three major aspects of nanostructured interfaces - nanotopographical control, dynamic behaviour and intracellular manipulation and sensing - where efforts are continuously being made to further understand cell function and provide new ways to control cell behaviour. A critical reflection of the current status and future challenges are discussed as a conclusion to the review.

  16. Investigation of the behaviour of solid acid catalysts for acylations and cyanisations of aromatics. Final report; Untersuchungen zur Wirkungsweise von festen sauren Katalysatoren bei Acylierungen und Cyanierungen von Aromaten. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kemnitz, E.

    2002-01-01

    The present state of the art in the field of FRIEDEL-CRAFTS-ACYLATIONS is characterized by the application of homogenous catalysts (at least stochiometric amounts) like AlCl{sub 3} or FeCl{sub 3}. Problems arising from this application are corrosions, difficult product separations from the catalyst and the origin of acid waste water. Hence, the aim of this project was the development of suitable solid catalysts which overcome the problems ascribed above. Sulfated zirconia (SZ) was found to be an excellent solid Br.o/nsted-acid to be used especially in their aerogel or cryogel form. Thus with this catalyst system, in the benzoylation of anisol nearly 100% conversion may be achieved. In this way it could be proved, that with SZ a solid Br.o/nsted-acid might be available which gives reasonable hope to substitute in a near future, at least for some reactions, the classical homogeneous catalysts and to overcome their problems in use. (orig.)

  17. Designing beauty the art of cellular automata

    CERN Document Server

    Martínez, Genaro

    2016-01-01

    This fascinating, colourful book offers in-depth insights and first-hand working experiences in the production of art works, using simple computational models with rich morphological behaviour, at the edge of mathematics, computer science, physics and biology. It organically combines ground breaking scientific discoveries in the theory of computation and complex systems with artistic representations of the research results. In this appealing book mathematicians, computer scientists, physicists, and engineers brought together marvelous and esoteric patterns generated by cellular automata, which are arrays of simple machines with complex behavior. Configurations produced by cellular automata uncover mechanics of dynamic patterns formation, their propagation and interaction in natural systems: heart pacemaker, bacterial membrane proteins, chemical rectors, water permeation in soil, compressed gas, cell division, population dynamics, reaction-diffusion media and self-organisation. The book inspires artists to tak...

  18. Construction of living cellular automata using the Physarum plasmodium

    Science.gov (United States)

    Shirakawa, Tomohiro; Sato, Hiroshi; Ishiguro, Shinji

    2015-04-01

    The plasmodium of Physarum polycephalum is a unicellular and multinuclear giant amoeba that has an amorphous cell body. To clearly observe how the plasmodium makes decisions in its motile and exploratory behaviours, we developed a new experimental system to pseudo-discretize the motility of the organism. In our experimental space that has agar surfaces arranged in a two-dimensional lattice, the continuous and omnidirectional movement of the plasmodium was limited to the stepwise one, and the direction of the locomotion was also limited to four neighbours. In such an experimental system, a cellular automata-like system was constructed using the living cell. We further analysed the exploratory behaviours of the plasmodium by duplicating the experimental results in the simulation models of cellular automata. As a result, it was revealed that the behaviours of the plasmodium are not reproduced by only local state transition rules; and for the reproduction, a kind of historical rule setting is needed.

  19. Schema Redescription in Cellular Automata: Revisiting Emergence in Complex Systems

    CERN Document Server

    Marques-Pita, Manuel

    2011-01-01

    We present a method to eliminate redundancy in the transition tables of Boolean automata: schema redescription with two symbols. One symbol is used to capture redundancy of individual input variables, and another to capture permutability in sets of input variables: fully characterizing the canalization present in Boolean functions. Two-symbol schemata explain aspects of the behaviour of automata networks that the characterization of their emergent patterns does not capture. We use our method to compare two well-known cellular automata for the density classification task: the human engineered CA GKL, and another obtained via genetic programming. We show that despite having very different collective behaviour, these rules are very similar. Indeed, GKL is a special case of GP. Therefore, we demonstrate that it is more feasible to compare cellular automata via schema redescriptions of their rules, than by looking at their emergent behaviour, leading us to question the tendency in complexity research to pay much m...

  20. Epigenetics and Cellular Metabolism

    Science.gov (United States)

    Xu, Wenyi; Wang, Fengzhong; Yu, Zhongsheng; Xin, Fengjiao

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well. PMID:27695375

  1. A systems-based mathematical modelling framework for investigating the effect of drugs on solid tumours

    Directory of Open Access Journals (Sweden)

    Liu Cong

    2011-12-01

    Full Text Available Abstract Background Elucidating the effects of drugs on solid tumours is a highly challenging multi-level problem, since this involves many complexities associated with transport and cellular response, which in turn is characterized by highly non-linear chemical signal transduction. Appropriate systems frameworks are needed to seriously address the sources of these complexities, especially from the cellular side. Results We develop a skeletal modelling framework incorporating interstitial drug transport, intracellular signal processing and cell population descriptions. The descriptions aim to appropriately capture the nature of information flow. The model is deliberately formulated to start with simple intracellular descriptions so that additional features can be incorporated in a modular fashion. Two kinds of intracellular signalling modules which describe the drug effect were considered, one a monostable switch and the other a bistable switch. Analysis of our model revealed how different drug stimuli can lead to cell killing in the tumour. Interestingly both modules considered exhibited similar trends. The effects of important parameters were also studied. Conclusions We have created a predictive systems platform integrating drug transport and cellular response which can be systematically augmented to include additional layers of cellular complexity. Our results indicate that intracellular signalling models which are qualitatively different can give rise to similar behaviour to simple (and typical stimuli, and that validating intracellular descriptions must be performed with care by considering a variety of drug stimuli.

  2. Cellular structural biology.

    Science.gov (United States)

    Ito, Yutaka; Selenko, Philipp

    2010-10-01

    While we appreciate the complexity of the intracellular environment as a general property of every living organism, we collectively lack the appropriate tools to analyze protein structures in a cellular context. In-cell NMR spectroscopy represents a novel biophysical tool to investigate the conformational and functional characteristics of biomolecules at the atomic level inside live cells. Here, we review recent in-cell NMR developments and provide an outlook towards future applications in prokaryotic and eukaryotic cells. We hope to thereby emphasize the usefulness of in-cell NMR techniques for cellular studies of complex biological processes and for structural analyses in native environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Cellular blue naevus

    Directory of Open Access Journals (Sweden)

    Mittal R

    2001-01-01

    Full Text Available A 31-year-old man had asymptomatic, stationary, 1.5X2 cm, shiny, smooth, dark blue nodule on dorsum of right hand since 12-14 years. In addition he had developed extensive eruption of yellow to orange papulonodular lesions on extensors of limbs and buttocks since one and half months. Investigations confirmed that yellow papules were xanthomatosis and he had associated diabetes mellitus and hyperlipidaemia. Biopsy of blue nodule confirmed the clinical diagnosis of cellular blue naevus. Cellular blue naevus is rare and its association with xanthomatosis and diabetes mellitus were interesting features of above patients which is being reported for its rarity.

  4. Mathematical modelling of municipal solid waste incineration and thermodynamic study of the behaviour of heavy metals; Modelisation de l'incineration sur grille d'ordures menageres et approche thermodynamique du comportement des metaux lourds

    Energy Technology Data Exchange (ETDEWEB)

    Menard, Y.

    2003-07-15

    The present dissertation describes experimental and theoretical investigations undertaken for the mathematical modelling of municipal solid waste (MSW) incineration in a grate furnace and the thermodynamic study of the speciation of heavy metals (HM), originally contained into MSW, during combustion. Thermogravimetric and gaseous analysis (mass spectrometry and gas chromatography) experiments were performed on MSW samples to get pyrolysis kinetics and to quantify the gaseous species that evolve during the primary reactions of devolatilization. Other experiments were carried out in a fixed bed pilot-scale reactor: the combustion of two types of solids (wood chips and MSW) was studied, and the influence of operating conditions (flow rate, staging and temperature of the primary air) as well as fuel characteristics (moisture content, inert material fraction, lower calorific value) was investigated. A mathematical model was developed for simulating the combustion of a solid fuel, either in a fixed bed reactor or on the grate of an incineration plant. It has been validated by comparison of the calculated results and the experiments carried out on the pilot. Thanks to this model, we have been able to localize the different processes taking place in the fuel bed and to evaluate the influence of the operating conditions on the combustion efficiency. Numerical simulations of the gas flow and combustion in the post-combustion chamber and the heater of an incineration plant were performed using the CFD code FLUENT. The local thermal conditions as well as local gaseous species concentrations obtained from these simulations were eventually used to carry out thermodynamic calculations of the speciation of HM during incineration. (author)

  5. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  6. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Cellular rehabilitation of photobiomodulation

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Yuan, Jian-Qin; Wang, Yan-Fang; Xu, Xiao-Yang; Liu, Song-Hao

    2007-05-01

    Homeostasis is a term that refers to constancy in a system. A cell in homeostasis normally functions. There are two kinds of processes in the internal environment and external environment of a cell, the pathogenic processes (PP) which disrupts the old homeostasis (OH), and the sanogenetic processes (SP) which restores OH or establishes a new homeostasis (NH). Photobiomodualtion (PBM), the cell-specific effects of low intensity monochromatic light or low intensity laser irradiation (LIL) on biological systems, is a kind of modulation on PP or SP so that there is no PBM on a cell in homeostasis. There are two kinds of pathways mediating PBM, the membrane endogenetic chromophores mediating pathways which often act through reactive oxygen species, and membrane proteins mediating pathways which often enhance cellular SP so that it might be called cellular rehabilitation. The cellular rehabilitation of PBM will be discussed in this paper. It is concluded that PBM might modulate the disruption of cellular homeostasis induced by pathogenic factors such as toxin until OH has been restored or NH has been established, but can not change homeostatic processes from one to another one.

  8. Cellular Response to Irradiation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; YAN Shi-Wei

    2011-01-01

    To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions.It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

  9. Solid consistency

    Science.gov (United States)

    Bordin, Lorenzo; Creminelli, Paolo; Mirbabayi, Mehrdad; Noreña, Jorge

    2017-03-01

    We argue that isotropic scalar fluctuations in solid inflation are adiabatic in the super-horizon limit. During the solid phase this adiabatic mode has peculiar features: constant energy-density slices and comoving slices do not coincide, and their curvatures, parameterized respectively by ζ and Script R, both evolve in time. The existence of this adiabatic mode implies that Maldacena's squeezed limit consistency relation holds after angular average over the long mode. The correlation functions of a long-wavelength spherical scalar mode with several short scalar or tensor modes is fixed by the scaling behavior of the correlators of short modes, independently of the solid inflation action or dynamics of reheating.

  10. Organizational Behaviour in Construction

    DEFF Research Database (Denmark)

    Kreiner, Kristian

    2013-01-01

    Review of: Organizational Behaviour in Construction / Anthony Walker (Wiley-Blackwell,2011 336 pp)......Review of: Organizational Behaviour in Construction / Anthony Walker (Wiley-Blackwell,2011 336 pp)...

  11. Recycling as moral behaviour

    DEFF Research Database (Denmark)

    Thøgersen, John

    of Reasoned Action (TRA) with regard to understanding recycling behaviour. Further, examples of misleading policy conclusions are discussed suggested that within the framework of cognitive psychology, Schwartz's model of altruistic behaviour offers a more satisfying starting point for understanding recycling......It is argued in this paper that in the affluent, industrial societies, environmental behaviours like recycling are typically classified within ""the domain of morality"" in people's minds. Intentions regarding these types of behaviours are not ba a thorough - conscious or unconscious - calculation...

  12. Neurotechnological Behavioural Treatment of Criminal Offenders

    DEFF Research Database (Denmark)

    Ryberg, Jesper; Petersen, Thomas Søbirk

    2013-01-01

    Whether it is morally acceptable to offer rehabilitation by CNS-intervention to criminals as a condition for early release constitutes an important neuroethical question. Bomann-Larsen has recently suggested that such interventions are unacceptable if the offered treatment is not narrowly targeted...... at the behaviour for which the criminal is convicted. In this article it is argued that Bomann-Larsen's analysis of the morality of offers does not provide a solid base for this conclusion and that, even if the analysis is assumed to be correct, it still does not follow that voluntary rehabilitation schemes...... targeting behaviour beyond the act for which a criminal is convicted are inappropriate....

  13. Organizational Behaviour Study Material

    OpenAIRE

    P. Sreeramana Aithal

    2016-01-01

    An overview of Organizational Behaviour – History of Organisational Behaviour and its  emergence as a disciple-emerging perspective Organizational Behaviour.  Individual process in organisation – Learning, perception and attribution- Individual differences - Basic concepts of motivation - Advanced concepts of motivation. Group process in Organisation – Group dynamics, leadership theories - Power, politics and conflict - inter- personal communication. Enhancing individu...

  14. A full computation-relevant topological dynamics classification of elementary cellular automata

    OpenAIRE

    SchÜle, M.; Stoop, R.

    2012-01-01

    Cellular automata are both computational and dynamical systems. We give a complete classification of the dynamic behaviour of elementary cellular automata (ECA) in terms of fundamental dynamic system notions such as sensitivity and chaoticity. The "complex" ECA emerge to be sensitive, but not chaotic and not eventually weakly periodic. Based on this classification, we conjecture that elementary cellular automata capable of carrying out complex computations, such as needed for Turing-universal...

  15. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  16. Post-Failure behaviour of pyroclastic debris flow

    Science.gov (United States)

    Scotto di Santolo, Anna; Pellegrino, Anna Maria; Evangelista, Aldo; Coussot, Philippe

    2010-05-01

    The Campania Region is covered by pyroclastic soils accumulated in the last tens of thousands of years as a result of volcanic activity of Campi Flegrei (Phlegrean Fields) and Somma-Vesuvio. These materials cover the slope of the hilly area of Naples and mountain sides of Appennino. Even if they present significant physical and mechanical differences from site to site, they are posing the same geotechnical problems: they are usually unsaturated and collapse due to the increase of water content after prolonged rains creating simple or complex type of landslides (translational or rotational sliding or falls that lead to debris flows). While the mechanical properties of natural soils are the object of a number of research works, the evolution of the material after failure is much less often studied. Typically the post failure behaviour of this material may be "solid-like" or "fluid-like", according to causes that are not well-known. The object of this presentation is the study of the rheological behaviour of the "fluid like" material mixtures with fluid mechanics tools. Three natural pyroclastic deposits were sampled and the soils were remixed with distilled water at different solid volume fractions. The behaviour of these mixtures was investigated like a fluid with a vane rotor rheometer and an inclined plane. The main results are that the rheological behaviour is strongly related to the solid volume concentration, but the transition between solid-like to fluid-like behaviour occurs in a small range of solid concentration slightly different for each material tested. In the fluid-like behaviour the material mixtures behave like a yield stress fluid and a classical Herschel-Bulkley model well represents the experimental data. Nevertheless a hysteresis effect, associated with instability of the material behaviour, is observed for the largest solid concentrations. In that case the material starts to flow abruptly beyond a critical stress and rapidly reaches a relatively

  17. Long-term behaviour of solid oxide fuel cell interconnect materials in contact with Ni-mesh during exposure in simulated anode gas at 700 and 800 °C

    Science.gov (United States)

    Garcia-Fresnillo, L.; Shemet, V.; Chyrkin, A.; de Haart, L. G. J.; Quadakkers, W. J.

    2014-12-01

    In the present study the long-term behaviour of two ferritic steels, Crofer 22 APU and Crofer 22H, in contact with a Ni-mesh during exposure in simulated anode gas, Ar-4%H2-2%H2O, at 700 and 800 °C for exposure times up to 3000 h was investigated. Ni diffusion from the Ni-mesh into the steel resulted in the formation of an austenitic zone whereas diffusion of iron and chromium from the steel into the Ni-mesh resulted in the formation of chromia base oxides in the Ni-mesh. Depending on the chemical composition of the steel, the temperature and the exposure time, interdiffusion processes between ferritic steel and Ni-mesh also resulted in σ-phase formation at the austenite-ferrite interface and in Laves-phase dissolution in the austenitic zone. The extent and morphology of the σ-phase formation are discussed on the basis of thermodynamic considerations, including reaction paths in the ternary alloy system Fe-Ni-Cr.

  18. Breakdown of elasticity in amorphous solids

    Science.gov (United States)

    Biroli, Giulio; Urbani, Pierfrancesco

    2016-12-01

    What characterizes a solid is the way that it responds to external stresses. Ordered solids, such as crystals, exhibit an elastic regime followed by a plastic regime, both understood microscopically in terms of lattice distortion and dislocations. For amorphous solids the situation is instead less clear, and the microscopic understanding of the response to deformation and stress is a very active research topic. Several studies have revealed that even in the elastic regime the response is very jerky at low temperature, resembling very much the response of disordered magnetic materials. Here we show that in a very large class of amorphous solids this behaviour emerges upon decreasing temperature, as a phase transition, where standard elastic behaviour breaks down. At the transition all nonlinear elastic moduli diverge and standard elasticity theory no longer holds. Below the transition, the response to deformation becomes history- and time-dependent.

  19. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  20. Study of the behaviour of gaseous pollutants during the incineration of municipal solid waste in a circulating fluidized bed; Etude du devenir des polluants gazeux lors de l`incineration d`ordures menageres en lit fluidise circulant

    Energy Technology Data Exchange (ETDEWEB)

    Desroches-Ducarne, E.

    1997-09-30

    The Circulating Fluidized Bed (CFB) combustor seems to be a promising tool, being able to burn a variety of fuels whilst maintaining low emissions levels. The present work describes an experimental and theoretical investigation into the formation and destruction of acid gases (HCl and SO{sub 2}) and nitrogen oxides (NO and N{sub 2}O) during Municipal Solid Waste incineration. Experiments were conducted on six different fuels (namely MSW, mixtures of wood, paper, plastics, polyethylene...). The effect of five parameters (temperature, excess air, air staging, calcium addition and moisture) on the emissions levels was investigated. A statistical study on the experimental data allowed us to quantify the impact of the operating conditions and the influence of the fuel characteristics. A mathematical model has been developed which includes the main physical and chemical steps of combustion in CFB and which predicts the pollutant emissions under various operating conditions. A parametric study of the influence of operating conditions on emissions showed that in most cases the trends predicted by the model are in agreement with the experimental observations. (author) 175 refs.

  1. Chaotic phenomena in Josephson circuits coupled quantum cellular neural networks

    Institute of Scientific and Technical Information of China (English)

    Wang Sen; Cai Li; Li Qin; Wu Gang

    2007-01-01

    In this paper the nonlinear dynamical behaviour of a quantum cellular neural network (QCNN) by coupling Josephson circuits was investigated and it was shown that the QCNN using only two of them can cause the onset of chaotic oscillation. The theoretical analysis and simulation for the two Josephson-circuits-coupled QCNN have been done by using the amplitude and phase as state variables. The complex chaotic behaviours can be observed and then proved by calculating Lyapunov exponents. The study provides valuable information about QCNNs for future application in high-parallel signal processing and novel chaotic generators.

  2. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  3. Failover in cellular automata

    CERN Document Server

    Kumar, Shailesh

    2010-01-01

    A cellular automata (CA) configuration is constructed that exhibits emergent failover. The configuration is based on standard Game of Life rules. Gliders and glider-guns form the core messaging structure in the configuration. The blinker is represented as the basic computational unit, and it is shown how it can be recreated in case of a failure. Stateless failover using primary-backup mechanism is demonstrated. The details of the CA components used in the configuration and its working are described, and a simulation of the complete configuration is also presented.

  4. Review of cellular mechanotransduction

    Science.gov (United States)

    Wang, Ning

    2017-06-01

    Living cells and tissues experience physical forces and chemical stimuli in the human body. The process of converting mechanical forces into biochemical activities and gene expression is mechanochemical transduction or mechanotransduction. Significant advances have been made in understanding mechanotransduction at the cellular and molecular levels over the last two decades. However, major challenges remain in elucidating how a living cell integrates signals from mechanotransduction with chemical signals to regulate gene expression and to generate coherent biological responses in living tissues in physiological conditions and diseases.

  5. Cellular automata: structures

    OpenAIRE

    Ollinger, Nicolas

    2002-01-01

    Jury : François Blanchard (Rapporteur), Marianne Delorme (Directeur), Jarkko Kari (Président), Jacques Mazoyer (Directeur), Dominique Perrin, Géraud Sénizergues (Rapporteur); Cellular automata provide a uniform framework to study an important problem of "complex systems" theory: how and why do system with a easily understandable -- local -- microscopic behavior can generate a more complicated -- global -- macroscopic behavior? Since its introduction in the 40s, a lot of work has been done to ...

  6. Behavioural present value

    OpenAIRE

    Krzysztof Piasecki

    2013-01-01

    Impact of chosen behavioural factors on imprecision of present value is discussed here. The formal model of behavioural present value is offered as a result of this discussion. Behavioural present value is described here by fuzzy set. These considerations were illustrated by means of extensive numerical case study. Finally there are shown that in proposed model the return rate is given, as a fuzzy probabilistic set.

  7. Rethinking retailer buying behaviour

    DEFF Research Database (Denmark)

    Esbjerg, Lars

    2001-01-01

    Research of retailer buying behaviour has previously focused on the buying decision. In this paper a new approach to studying retailer buying behaviour is suggested, one which focuses on the sensemaking processes leading up to a decision being made. A research project taking a sensemaking...... perspective is outlined and the implications and expected contribution of studying retailer buying behaviour from a sensemaking perspective are discussed....

  8. Incentives and Prosocial Behaviour

    OpenAIRE

    Bénabou, Roland; Tirole, Jean

    2004-01-01

    We build a theory of prosocial behaviour that combines heterogeneity in individual altruism and greed with concerns for social reputation or self-respect. The presence of rewards or punishments creates doubt as to the true motive for which good deeds are performed, and this ‘overjustification effect’ can result in a net crowding out of prosocial behaviour by extrinsic incentives. The model also allows us to identify settings that are conducive to multiple social norms of behaviour, and those ...

  9. Changing doctor prescribing behaviour

    DEFF Research Database (Denmark)

    Gill, P.S.; Mäkelä, M.; Vermeulen, K.M.

    1999-01-01

    The aim of this overview was to identify interventions that change doctor prescribing behaviour and to derive conclusions for practice and further research. Relevant studies (indicating prescribing as a behaviour change) were located from a database of studies maintained by the Cochrane Collabora......The aim of this overview was to identify interventions that change doctor prescribing behaviour and to derive conclusions for practice and further research. Relevant studies (indicating prescribing as a behaviour change) were located from a database of studies maintained by the Cochrane...

  10. Cellular arsenic transport pathways in mammals.

    Science.gov (United States)

    Roggenbeck, Barbara A; Banerjee, Mayukh; Leslie, Elaine M

    2016-11-01

    Natural contamination of drinking water with arsenic results in the exposure of millions of people world-wide to unacceptable levels of this metalloid. This is a serious global health problem because arsenic is a Group 1 (proven) human carcinogen and chronic exposure is known to cause skin, lung, and bladder tumors. Furthermore, arsenic exposure can result in a myriad of other adverse health effects including diseases of the cardiovascular, respiratory, neurological, reproductive, and endocrine systems. In addition to chronic environmental exposure to arsenic, arsenic trioxide is approved for the clinical treatment of acute promyelocytic leukemia, and is in clinical trials for other hematological malignancies as well as solid tumors. Considerable inter-individual variability in susceptibility to arsenic-induced disease and toxicity exists, and the reasons for such differences are incompletely understood. Transport pathways that influence the cellular uptake and export of arsenic contribute to regulating its cellular, tissue, and ultimately body levels. In the current review, membrane proteins (including phosphate transporters, aquaglyceroporin channels, solute carrier proteins, and ATP-binding cassette transporters) shown experimentally to contribute to the passage of inorganic, methylated, and/or glutathionylated arsenic species across cellular membranes are discussed. Furthermore, what is known about arsenic transporters in organs involved in absorption, distribution, and metabolism and how transport pathways contribute to arsenic elimination are described.

  11. [Senescence and cellular immortality].

    Science.gov (United States)

    Trentesaux, C; Riou, J-F

    2010-11-01

    Senescence was originally described from the observation of the limited ability of normal cells to grow in culture, and may be generated by telomere erosion, accumulation of DNA damages, oxidative stress and modulation of oncogenes or tumor suppressor genes. Senescence corresponds to a cellular response aiming to control tumor progression by limiting cell proliferation and thus constitutes an anticancer barrier. Senescence is observed in pre-malignant tumor stages and disappears from malignant tumors. Agents used in standard chemotherapy also have the potential to induce senescence, which may partly explain their therapeutic activities. It is possible to restore senescence in tumors using targeted therapies that triggers telomere dysfunction or reactivates suppressor genes functions, which are essential for the onset of senescence.

  12. Engineering Cellular Metabolism.

    Science.gov (United States)

    Nielsen, Jens; Keasling, Jay D

    2016-03-10

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation.

  13. Cellular image classification

    CERN Document Server

    Xu, Xiang; Lin, Feng

    2017-01-01

    This book introduces new techniques for cellular image feature extraction, pattern recognition and classification. The authors use the antinuclear antibodies (ANAs) in patient serum as the subjects and the Indirect Immunofluorescence (IIF) technique as the imaging protocol to illustrate the applications of the described methods. Throughout the book, the authors provide evaluations for the proposed methods on two publicly available human epithelial (HEp-2) cell datasets: ICPR2012 dataset from the ICPR'12 HEp-2 cell classification contest and ICIP2013 training dataset from the ICIP'13 Competition on cells classification by fluorescent image analysis. First, the reading of imaging results is significantly influenced by one’s qualification and reading systems, causing high intra- and inter-laboratory variance. The authors present a low-order LP21 fiber mode for optical single cell manipulation and imaging staining patterns of HEp-2 cells. A focused four-lobed mode distribution is stable and effective in optical...

  14. Multiuser Cellular Network

    CERN Document Server

    Bao, Yi; Chen, Ming

    2011-01-01

    Modern radio communication is faced with a problem about how to distribute restricted frequency to users in a certain space. Since our task is to minimize the number of repeaters, a natural idea is enlarging coverage area. However, coverage has restrictions. First, service area has to be divided economically as repeater's coverage is limited. In this paper, our fundamental method is to adopt seamless cellular network division. Second, underlying physics content in frequency distribution problem is interference between two close frequencies. Consequently, we choose a proper frequency width of 0.1MHz and a relevantly reliable setting to apply one frequency several times. We make a few general assumptions to simplify real situation. For instance, immobile users yield to homogenous distribution; repeaters can receive and transmit information in any given frequency in duplex operation; coverage is mainly decided by antenna height. Two models are built up to solve 1000 users and 10000 users situations respectively....

  15. A solid-fluid mixture model allowing for solid dilatation under external pressure

    CERN Document Server

    Sciarra, Giulio; Hutter, Kolumban

    2010-01-01

    A sponge subjected to an increase of the outside fluid pressure expands its volume but nearly mantains its true density and thus gives way to an increase of the interstitial volume. This behaviour, not yet properly described by solid-fluid mixture theories, is studied here by using the Principle of Virtual Power with the most simple dependence of the free energy as a function of the partial apparent densities of the solid and the fluid. The model is capable of accounting for the above mentioned dilatational behaviour, but in order to isolate its essential features more clearly we compromise on the other aspects of deformation.

  16. Stabilization of behaviours

    NARCIS (Netherlands)

    Geest, van der Robert

    1996-01-01

    In this paper we characterize the set of all restrictions on the behaviour of a plant that shape the characteristic polynomial of the closed-loop system. These control laws include both classical feedback laws and singular feedback laws. One of the results is the behavioural version of the Youla-Jab

  17. Rethinking retailer buying behaviour

    DEFF Research Database (Denmark)

    Esbjerg, Lars

    2001-01-01

    Research of retailer buying behaviour has previously focused on the buying decision. In this paper a new approach to studying retailer buying behaviour is suggested, one which focuses on the sensemaking processes leading up to a decision being made. A research project taking a sensemaking...

  18. Experimental study on the rheological behaviour of coal ash slurries

    Directory of Open Access Journals (Sweden)

    Assefa K.M.

    2015-12-01

    Full Text Available Extensive experimental investigations were carried out to evaluate the rheological behaviour of fly ash (FA slurry without and with the addition of bottom ash (BA and BA slurry without and with the addition of FA. The FA slurries exhibited Bingham behaviour at solid mass concentrations ranging from 60–65% and mixing proportions from 10– 40%. A substantial reduction in yield stress was observed except for mixing proportion of 40% on which the yield stress and viscosity were increased drastically for all solid concentrations. Hence, it can be concluded that the yield stress and viscosity of FA slurry were very much influenced by adding BA up to the mixing proportion of 30%. The rheological behaviour of BA slurries with and without the addition of FA in proportions of 10–50% was investigated and exhibited Newtonian behaviours for solid mass concentrations ranging from 30–50% without and with the addition of FA. The viscosity increases with increasing the solid concentrations and proportion of FA. Based on these experimental data, a correlation was developed to predict the relative viscosity of BA slurries as a function of solid volume fraction and FA mass proportion of 0–50% and the RMSE and R2 values showed good agreement between the experimental and the predicted data.

  19. Computing by Temporal Order: Asynchronous Cellular Automata

    Directory of Open Access Journals (Sweden)

    Michael Vielhaber

    2012-08-01

    Full Text Available Our concern is the behaviour of the elementary cellular automata with state set 0,1 over the cell set Z/nZ (one-dimensional finite wrap-around case, under all possible update rules (asynchronicity. Over the torus Z/nZ (n<= 11,we will see that the ECA with Wolfram rule 57 maps any v in F_2^n to any w in F_2^n, varying the update rule. We furthermore show that all even (element of the alternating group bijective functions on the set F_2^n = 0,...,2^n-1, can be computed by ECA57, by iterating it a sufficient number of times with varying update rules, at least for n <= 10. We characterize the non-bijective functions computable by asynchronous rules.

  20. Behavioural aspects of terrorism.

    Science.gov (United States)

    Leistedt, Samuel J

    2013-05-10

    Behavioural and social sciences are useful in collecting and analysing intelligence data, understanding terrorism, and developing strategies to combat terrorism. This article aims to examine the psychopathological concepts of terrorism and discusses the developing roles for behavioural scientists. A systematic review was conducted of studies investigating behavioural aspects of terrorism. These studies were identified by a systematic search of databases, textbooks, and a supplementary manual search of references. Several fundamental concepts were identified that continue to influence the motives and the majority of the behaviours of those who support or engage in this kind of specific violence. Regardless of the psychological aspects and new roles for psychiatrists, the behavioural sciences will continue to be called upon to assist in developing better methods to gather and analyse intelligence, to understand terrorism, and perhaps to stem the radicalisation process. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. The biomechanical behaviour of the hyalinized periodontal ligament in dogs during experimental orthodontic tooth movement

    NARCIS (Netherlands)

    Jonsdottir, S.H.; Giesen, E.B.W.; Maltha, J.C.

    2012-01-01

    During orthodontic tooth movement, the mechanical behaviour of the extracellular matrix of the periodontal ligament (PDL) determines the cellular processes involved in turnover of the PDL and alveolar bone. This mechanical behaviour is the basis for finite element (FE) models and FE analyses. Five y

  2. Cellular bioluminescence imaging.

    Science.gov (United States)

    Welsh, David K; Noguchi, Takako

    2012-08-01

    Bioluminescence imaging of live cells has recently been recognized as an important alternative to fluorescence imaging. Fluorescent probes are much brighter than bioluminescent probes (luciferase enzymes) and, therefore, provide much better spatial and temporal resolution and much better contrast for delineating cell structure. However, with bioluminescence imaging there is virtually no background or toxicity. As a result, bioluminescence can be superior to fluorescence for detecting and quantifying molecules and their interactions in living cells, particularly in long-term studies. Structurally diverse luciferases from beetle and marine species have been used for a wide variety of applications, including tracking cells in vivo, detecting protein-protein interactions, measuring levels of calcium and other signaling molecules, detecting protease activity, and reporting circadian clock gene expression. Such applications can be optimized by the use of brighter and variously colored luciferases, brighter microscope optics, and ultrasensitive, low-noise cameras. This article presents a review of how bioluminescence differs from fluorescence, its applications to cellular imaging, and available probes, optics, and detectors. It also gives practical suggestions for optimal bioluminescence imaging of single cells.

  3. Cellular neurothekeoma with melanocytosis.

    Science.gov (United States)

    Wu, Ren-Chin; Hsieh, Yi-Yueh; Chang, Yi-Chin; Kuo, Tseng-Tong

    2008-02-01

    Cellular neurothekeoma (CNT) is a benign dermal tumor mainly affecting the head and neck and the upper extremities. It is characterized histologically by interconnecting fascicles of plump spindle or epithelioid cells with ample cytoplasm infiltrating in the reticular dermis. The histogenesis of CNT has been controversial, although it is generally regarded as an immature counterpart of classic/myxoid neurothekeoma, a tumor with nerve sheath differentiation. Two rare cases of CNT containing melanin-laden cells were described. Immunohistochemical study with NKI/C3, vimentin, epithelial membrane antigen, smooth muscle antigen, CD34, factor XIIIa, collagen type IV, S100 protein and HMB-45 was performed. Both cases showed typical growth pattern of CNT with interconnecting fascicles of epithelioid cells infiltrating in collagenous stroma. One of the nodules contained areas exhibiting atypical cytological features. Melanin-laden epithelioid or dendritic cells were diffusely scattered throughout one nodule, and focally present in the peripheral portion of the other nodule. Both nodules were strongly immunoreactive to NKI/C3 and vimentin, but negative to all the other markers employed. CNT harboring melanin-laden cells may pose diagnostic problems because of their close resemblance to nevomelanocytic lesions and other dermal mesenchymal tumors. These peculiar cases may also provide further clues to the histogenesis of CNT.

  4. Significant determinants of mouse pain behaviour.

    Directory of Open Access Journals (Sweden)

    Michael S Minett

    Full Text Available Transgenic mouse behavioural analysis has furthered our understanding of the molecular and cellular mechanisms underlying damage sensing and pain. However, it is not unusual for conflicting data on the pain phenotypes of knockout mice to be generated by reputable groups. Here we focus on some technical aspects of measuring mouse pain behaviour that are often overlooked, which may help explain discrepancies in the pain literature. We examined touch perception using von Frey hairs and mechanical pain thresholds using the Randall-Selitto test. Thermal pain thresholds were measured using the Hargreaves apparatus and a thermal place preference test. Sodium channel Nav1.7 knockout mice show a mechanical deficit in the hairy skin, but not the paw, whilst shaving the abdominal hair abolished this phenotype. Nav1.7, Nav1.8 and Nav1.9 knockout mice show deficits in noxious mechanosensation in the tail, but not the paw. TRPA1 knockout mice, however, have a loss of noxious mechanosensation in the paw but not the tail. Studies of heat and cold sensitivity also show variability depending on the intensity of the stimulus. Deleting Nav1.7, Nav1.8 or Nav1.9 in Nav1.8-positive sensory neurons attenuates responses to slow noxious heat ramps, whilst responses to fast noxious heat ramps are only reduced when Nav1.7 is lost in large diameter sensory neurons. Deleting Nav1.7 from all sensory neurons attenuates responses to noxious cooling but not extreme cold. Finally, circadian rhythms dramatically influence behavioural outcome measures such as von Frey responses, which change by 80% over the day. These observations demonstrate that fully characterising the phenotype of a transgenic mouse strain requires a range of behavioural pain models. Failure to conduct behavioural tests at different anatomical locations, stimulus intensities, and at different points in the circadian cycle may lead to a pain behavioural phenotype being misinterpreted, or missed altogether.

  5. Foaming Behaviour, Structure, and Properties of Polypropylene Nanocomposites Foams

    Directory of Open Access Journals (Sweden)

    M. Antunes

    2010-01-01

    Full Text Available This work presents the preparation and characterization of compression-moulded montmorillonite and carbon nanofibre-polypropylene foams. The influence of these nanofillers on the foaming behaviour was analyzed in terms of the foaming parameters and final cellular structure and morphology of the foams. Both nanofillers induced the formation of a more isometric-like cellular structure in the foams, mainly observed for the MMT-filled nanocomposite foams. Alongside their crystalline characteristics, the nanocomposite foams were also characterized and compared with the unfilled ones regarding their dynamic-mechanical thermal behaviour. The nanocomposite foams showed higher specific storage moduli due to the reinforcement effect of the nanofillers and higher cell density isometric cellular structure. Particularly, the carbon nanofibre foams showed an increasingly higher electrical conductivity with increasing the amount of nanofibres, thus showing promising results as to produce electrically improved lightweight materials for applications such as electrostatic painting.

  6. Changing Information Retrieval Behaviours

    DEFF Research Database (Denmark)

    Constantiou, Ioanna D.; Lehrer, Christiane; Hess, Thomas

    2014-01-01

    The introduction of smartphones and the accompanying profusion of mobile data services have had a profound effect on individuals' lives. One of the most influential service categories is location-based services (LBS). Based on insights from behavioural decision-making, a conceptual framework is d...... on the continuance of LBS use and indicate changes in individuals' information retrieval behaviours in everyday life. In particular, the distinct value dimension of LBS in specific contexts of use changes individuals' behaviours towards accessing location-related information....

  7. Psychology: Inducing green behaviour

    Science.gov (United States)

    Thøgersen, John

    2013-02-01

    Economic arguments, such as saving money, are often used to promote pro-environmental actions -- for example, reducing energy use. However, research shows that people's environmental motives are sometimes better drivers of behavioural change.

  8. Energy efficiency and behaviour

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Kunnasvirta, Annika; Kiviluoto, Katariina

    The purpose of Work Package 5 Deliverable 5.1., “Case study reports on energy efficiency and behaviour” is to present examples of behavioral interventions to promote energy efficiency in cities. The case studies were collected in January – June 2014, and they represent behavioural interventions...... factors. The main addressees of D5.1. are city officials, NGO representatives, private sector actors and any other relevant actors who plan and realize behavioural energy efficiency interventions in European cities. The WP5 team will also further apply results from D5.1. with a more general model on how...... to conduct behavioural interventions, to be presented in Deliverable 5.5., the final report. This report will also provide valuable information for the WP6 general model for an Energy-Smart City. Altogether 38 behavioural interventions are analysed in this report. Each collected and analysed case study...

  9. Relaxing Behavioural Inheritance

    Directory of Open Access Journals (Sweden)

    Nuno Amálio

    2013-05-01

    Full Text Available Object-oriented (OO inheritance allows the definition of families of classes in a hierarchical way. In behavioural inheritance, a strong version, it should be possible to substitute an object of a subclass for an object of its superclass without any observable effect on the system. Behavioural inheritance is related to formal refinement, but, as observed in the literature, the refinement constraints are too restrictive, ruling out many useful OO subclassings. This paper studies behavioural inheritance in the context of ZOO, an object-oriented style for Z. To overcome refinement's restrictions, this paper proposes relaxations to the behavioural inheritance refinement rules. The work is presented for Z, but the results are applicable to any OO language that supports design-by-contract.

  10. Gender and Behaviour

    African Journals Online (AJOL)

    ... to articles, that reflect psychological and behavioural aspects of gender in general. ... Is entrepreneurial orientation a predictor of entrepreneurial activity? ... Personality traits and sexual satisfaction as determinants of marital satisfaction ...

  11. Energy Conservation Behaviour Toolkit

    NARCIS (Netherlands)

    Kalz, Marco; Börner, Dirk; Ternier, Stefaan; Specht, Marcus

    2013-01-01

    Kalz, M., Börner, D., Ternier, S., & Specht, M. (2013, 31 January). Energy Conservation Behaviour Toolkit. Presentation given at the symposium "Groene ICT en Duurzame ontwikkeling: Meters maken in het Hoger Onderwijs", Driebergen, The Netherlands.

  12. Recycling as moral behaviour

    DEFF Research Database (Denmark)

    Thøgersen, John

    of Reasoned Action (TRA) with regard to understanding recycling behaviour. Further, examples of misleading policy conclusions are discussed suggested that within the framework of cognitive psychology, Schwartz's model of altruistic behaviour offers a more satisfying starting point for understanding recycling......It is argued in this paper that in the affluent, industrial societies, environmental behaviours like recycling are typically classified within ""the domain of morality"" in people's minds. Intentions regarding these types of behaviours are not ba a thorough - conscious or unconscious - calculation...... of the balance of costs and benefits. Rather, they are a function of the person's moral beliefs, i.e., beliefs in what is the right or wrong thing to do. The paper gives a brief review of the literature with the intention of uncovering problems and shortcomings in the framework of the SEU-model and the Theory...

  13. Energy efficiency and behaviour

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Kunnasvirta, Annika; Kiviluoto, Katariina

    factors. The main addressees of D5.1. are city officials, NGO representatives, private sector actors and any other relevant actors who plan and realize behavioural energy efficiency interventions in European cities. The WP5 team will also further apply results from D5.1. with a more general model on how...... to conduct behavioural interventions, to be presented in Deliverable 5.5., the final report. This report will also provide valuable information for the WP6 general model for an Energy-Smart City. Altogether 38 behavioural interventions are analysed in this report. Each collected and analysed case study......The purpose of Work Package 5 Deliverable 5.1., “Case study reports on energy efficiency and behaviour” is to present examples of behavioral interventions to promote energy efficiency in cities. The case studies were collected in January – June 2014, and they represent behavioural interventions...

  14. Free fall and cellular automata

    Directory of Open Access Journals (Sweden)

    Pablo Arrighi

    2016-03-01

    Full Text Available Three reasonable hypotheses lead to the thesis that physical phenomena can be described and simulated with cellular automata. In this work, we attempt to describe the motion of a particle upon which a constant force is applied, with a cellular automaton, in Newtonian physics, in Special Relativity, and in General Relativity. The results are very different for these three theories.

  15. About Strongly Universal Cellular Automata

    Directory of Open Access Journals (Sweden)

    Maurice Margenstern

    2013-09-01

    Full Text Available In this paper, we construct a strongly universal cellular automaton on the line with 11 states and the standard neighbourhood. We embed this construction into several tilings of the hyperbolic plane and of the hyperbolic 3D space giving rise to strongly universal cellular automata with 10 states.

  16. Reactive Programming of Cellular Automata

    OpenAIRE

    Boussinot, Frédéric

    2004-01-01

    Implementation of cellular automata using reactive programming gives a way to code cell behaviors in an abstract and modular way. Multiprocessing also becomes possible. The paper describes the implementation of cellular automata with the reactive programming language LOFT, a thread-based extension of C. Self replicating loops considered in artificial life are coded to show the interest of the approach.

  17. Mathematical modelling in solid mechanics

    CERN Document Server

    Sofonea, Mircea; Steigmann, David

    2017-01-01

    This book presents new research results in multidisciplinary fields of mathematical and numerical modelling in mechanics. The chapters treat the topics: mathematical modelling in solid, fluid and contact mechanics nonconvex variational analysis with emphasis to nonlinear solid and structural mechanics numerical modelling of problems with non-smooth constitutive laws, approximation of variational and hemivariational inequalities, numerical analysis of discrete schemes, numerical methods and the corresponding algorithms, applications to mechanical engineering numerical aspects of non-smooth mechanics, with emphasis on developing accurate and reliable computational tools mechanics of fibre-reinforced materials behaviour of elasto-plastic materials accounting for the microstructural defects definition of structural defects based on the differential geometry concepts or on the atomistic basis interaction between phase transformation and dislocations at nano-scale energetic arguments bifurcation and post-buckling a...

  18. The heat-transfer performance of gas—solid trickle flow over a regularly stacked packing

    NARCIS (Netherlands)

    Verver, A.B.; Swaaij, van W.P.M.

    1986-01-01

    The heat-transfer behaviour of a countercurrent gas—solid trickle flow contactor is studied, using coarse sand particles as the solids phase. Experimental data on the overall heat-transfer rate constant between the gas flow and the solid particle flow were obtained in a 0.15 m square cross-section c

  19. Application and future of solid foams

    Science.gov (United States)

    Bienvenu, Yves

    2014-10-01

    To conclude this series of chapters on solid foam materials, a review of industrial current applications and of mid-term market perspectives centred on manmade foams is given, making reference to natural cellular materials. Although the polymeric foam industrial development overwhelms the rest and finds applications on many market segments, more attention will be paid to the emerging market of inorganic-especially metallic-foams (and cellular materials) and their applications, present or upcoming. It is shown that the final applications of solid foams are primarily linked to transport and the present-day development of the different classes of solid foams is contrasted between functional applications and structural applications. xml:lang="fr"

  20. Wave behaviour and noncomplementary particle behaviour in the same experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rangwala, Sadiq (Tata Institute of Fundamental Research, Bombay 400 005 (India)); Roy, S.M. (Tata Institute of Fundamental Research, Bombay 400 005 (India))

    1994-07-11

    Grangier, Roger and Aspect have recently performed beautiful experiments, which show that the same single photon source shows wave behaviour or particle behaviour depending on the experimental arrangement. We propose experiments in which quantum mechanics predicts wave behaviour and noncomplementary particle behaviour in the same experiment. ((orig.))

  1. Wave behaviour and noncomplementary particle behaviour in the same experiment

    Science.gov (United States)

    Rangwala, Sadiq; Roy, S. M.

    1994-07-01

    Grangier, Roger and Aspect have recently performed beautiful experiments, which show that the same single photon source shows wave behaviour or particle behaviour depending on the experimental arrangement. We propose experiments in which quantum mechanics predicts wave behaviour and noncomplementary particle behaviour in the same experiment.

  2. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  3. Cellular automata analysis and applications

    CERN Document Server

    Hadeler, Karl-Peter

    2017-01-01

    This book focuses on a coherent representation of the main approaches to analyze the dynamics of cellular automata. Cellular automata are an inevitable tool in mathematical modeling. In contrast to classical modeling approaches as partial differential equations, cellular automata are straightforward to simulate but hard to analyze. In this book we present a review of approaches and theories that allow the reader to understand the behavior of cellular automata beyond simulations. The first part consists of an introduction of cellular automata on Cayley graphs, and their characterization via the fundamental Cutis-Hedlund-Lyndon theorems in the context of different topological concepts (Cantor, Besicovitch and Weyl topology). The second part focuses on classification results: What classification follows from topological concepts (Hurley classification), Lyapunov stability (Gilman classification), and the theory of formal languages and grammars (Kůrka classification). These classifications suggest to cluster cel...

  4. Velocity dependant splash behaviour

    Science.gov (United States)

    Hamlett, C. A. E.; Shirtcliffe, N. J.; McHale, G.; Ahn, S.; Doerr, S. H.; Bryant, R.; Newton, M. I.

    2012-04-01

    Extreme soil water repellency can occur in nature via condensation of volatile organic compounds released during wildfires and can lead to increased erosion rate. Such extreme water repellent soil can be classified as superhydrophobic and shares similar chemical and topographical features to specifically designed superhydrophobic surfaces. Previous studies using high speed videography to investigate single droplet impact behaviour on artificial superhydrophobic have revealed three distinct modes of splash behaviour (rebound, pinned and fragmentation) which are dependent on the impact velocity of the droplet. In our studies, using high-speed videography, we show that such splash behaviour can be replicated on fixed 'model' water repellent soils (hydrophobic glass beads/particles). We show that the type of splash behaviour is dependent on both the size and chemical nature of the fixed particles. The particle shape also influences the splash behaviour as shown by drop impact experiments on fixed sand samples. We have also studied soil samples, as collected from the field, which shows that the type of droplet splash behaviour can lead to enhanced soil particle transport.

  5. The Dynamics of cellular motility

    OpenAIRE

    Murase, Masatoshi

    1992-01-01

    " This book presents new ideas and theories that account for oscillatory contraction in muscle and the various modes of flagellar and ciliary movements. Despite the great variety of dynamical behaviours, attempts have been made to model some of the specific modes, though not to account for the overall properties. I have tried to develop theoretical models and to interpret nearly all of the dynamical behaviours in terms of these models. This book is intended for students and specialists in bio...

  6. Agglomeration and Deposition Behaviour of Solid Recovered Fuel

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Jensen, Peter Arendt; Nielsen, Mads

    2015-01-01

    contains significant quantities of common plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Fluidized bed experiments to examine the pyrolysis of polymers have shown that bed agglomeration can result from melting plastics or sticky char residues in the case...... materials such as plastic and paper than mixed MSW [2]. The inhomogeneous nature of SRF [3] makes it difficult to combust and many problems may arise concerning e.g. combustion control, feeding of fuel [2,4], deposit formation [5], or accumulation of impurities [3]. Laboratory ash fusion tests typically...... of PET [11,12]. The main objective of this study was to characterize the combustion of SRF and especially the deposition propensity of SRF and the main constituents of SRF. This relates both to the low temperature deposits formed during plastic pyrolysis and the high temperature deposits formed by ash...

  7. Cellular and Porous Materials Thermal Properties Simulation and Prediction

    CERN Document Server

    Öchsner, Andreas; de Lemos, Marcelo J S

    2008-01-01

    Providing the reader with a solid understanding of the fundamentals as well as an awareness of recent advances in properties and applications of cellular and porous materials, this handbook and ready reference covers all important analytical and numerical methods for characterizing and predicting thermal properties. In so doing it directly addresses the special characteristics of foam-like and hole-riddled materials, combining theoretical and experimental aspects for characterization purposes.

  8. Information behaviour: models and concepts

    Directory of Open Access Journals (Sweden)

    Polona Vilar

    2005-01-01

    Full Text Available The article presents an overview of the research area of information behaviour. Information behaviour is defined as the behaviour of individuals in relation to information sources and channels, which results as a consequence of their information need, and encompasses passive and active searching of information, and its use. Theoretical foundations are presented, as well as some fundamental conceptual models of information behaviour and related concepts: information searching behaviour, which occurrs in active, purposeful searching for information, regardless of the information source used; and information seeking behaviour, which represents a micro-level of information searching behaviour, and is expressed by those individuals who interact with information retrieval systems.

  9. EFFECTIVENESS OF CELLULAR INJECTION MOLDING PROCESS

    Directory of Open Access Journals (Sweden)

    Tomasz Garbacz

    2013-06-01

    Full Text Available In a study of cellular injection, molding process uses polyvinylchloride PVC. Polymers modified with introducing blowing agents into them in the Laboratory of the Department of Technologies and Materiase of Technical University of Kosice. For technological reasons, blowing agents have a form of granules. In the experiment, the content of the blowing agent (0–2,0 % by mass fed into the processed polymer was adopted as a variable factor. In the studies presented in the article, the chemical blowing agents occurring in the granulated form with a diameter of 1.2 to 1.4 mm were used. The view of the technological line for cellular injection molding and injection mold cavity with injection moldings are shown in Figure 1. The results of the determination of selected properties of injection molded parts for various polymeric materials, obtained with different content of blowing agents, are shown in Figures 4-7. Microscopic examination of cross-sectional structure of the moldings were obtained using the author's position image analysis of porous structure. Based on analysis of photographs taken (Figures 7, 8, 9 it was found that the coating containing 1.0% of blowing agents is a clearly visible solid outer layer and uniform distribution of pores and their sizes are similar.

  10. Cellular systems biology profiling applied to cellular models of disease.

    Science.gov (United States)

    Giuliano, Kenneth A; Premkumar, Daniel R; Strock, Christopher J; Johnston, Patricia; Taylor, Lansing

    2009-11-01

    Building cellular models of disease based on the approach of Cellular Systems Biology (CSB) has the potential to improve the process of creating drugs as part of the continuum from early drug discovery through drug development and clinical trials and diagnostics. This paper focuses on the application of CSB to early drug discovery. We discuss the integration of protein-protein interaction biosensors with other multiplexed, functional biomarkers as an example in using CSB to optimize the identification of quality lead series compounds.

  11. Communication and abnormal behaviour.

    Science.gov (United States)

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  12. Lightweight 3D cellular composites inspired by balsa.

    Science.gov (United States)

    Malek, Sardar; Raney, Jordan; Lewis, Jennifer; Gibson, Lorna

    2017-02-13

    Additive manufacturing technologies offer new ways to fabricate cellular materials with composite cell walls, mimicking the structure and mechanical properties of woods. However, materials limitations and a lack of design tools have confined the usefulness of 3D printed cellular materials. We develop new carbon fiber reinforced, epoxy inks for 3D printing which result in printed materials with longitudinal Young's modulus up to 57 GPa (exceeding the longitudinal modulus of wood cell wall material). To guide the design of hierarchical cellular materials, we developed a parameterized, multi-scale, finite element model. Computational homogenization based on finite element simulations at multiple length scales is employed to obtain the elastic properties of the material at multiple length scales. Parameters affecting the elastic response of cellular composites, such as the volume fraction, orientation distribution, and aspect ratio of fibers within the cell walls as well as the cell geometry and relative density are included in the model. To validate the model, experiments are conducted on both solid carbon fiber/epoxy composites and cellular structures made from them, showing excellent agreement with model predictions, both at the cell-wall and at the cellular-structure levels. Using the model, cellular structures are designed and experimentally shown to achieve a specific stiffness nearly as high as that observed in balsa wood. The good agreement between the multi-scale model predictions and experimental data provides confidence in the practical utility of this model as a tool for designing novel 3D cellular composites with unprecedented specific elastic properties.

  13. A Course in Cellular Bioengineering.

    Science.gov (United States)

    Lauffenburger, Douglas A.

    1989-01-01

    Gives an overview of a course in chemical engineering entitled "Cellular Bioengineering," dealing with how chemical engineering principles can be applied to molecular cell biology. Topics used are listed and some key references are discussed. Listed are 85 references. (YP)

  14. Novel Materials for Cellular Nanosensors

    DEFF Research Database (Denmark)

    Sasso, Luigi

    The monitoring of cellular behavior is useful for the advancement of biomedical diagnostics, drug development and the understanding of a cell as the main unit of the human body. Micro- and nanotechnology allow for the creation of functional devices that enhance the study of cellular dynamics...... by providing platforms that offer biocompatible surfaces for the cell culturing in lab-on-chip devices integrated with optimized nanosensors with high specificities and sensitivities towards cellular analytes. In this project, novel materials were investigated with a focus on providing suitable surface...... modifications for electrochemical nanosensors for the detection of analytes released from cells. Two type of materials were investigated, each pertaining to the two different aspects of such devices: peptide nanostructures were studied for the creation of cellular sensing substrates that mimic in vivo surfaces...

  15. Occupants' window opening behaviour

    DEFF Research Database (Denmark)

    Fabi, Valentina; Andersen, Rune Korsholm; Corgnati, Stefano

    2012-01-01

    Energy consumption in buildings is influenced by several factors related to the building properties and the building controls, some of them highly connected to the behaviour of their occupants.In this paper, a definition of items referring to occupant behaviour related to the building control...... systems is proposed, based on studies presented in literature and a general process leading to the effects on energy consumptions is identified.Existing studies on the topic of window opening behaviour are highlighted and a theoretical framework to deal with occupants' interactions with building controls......, aimed at improving or maintaining the preferred indoor environmental conditions, is elaborated. This approach is used to look into the drivers for the actions taken by the occupants (windows opening and closing) and to investigate the existing models in literature of these actions for both residential...

  16. Changing physician prescribing behaviour.

    Science.gov (United States)

    Gray, J

    2006-01-01

    Didactic approaches to educating physicians and/or other health professionals do not produce changes in learner behaviour. Similarly, printed materials and practice guidelines have not been shown to change prescribing behaviour. Evidence-based educational approaches that do have an impact on provider behaviour include: teaching aimed at identified learning needs; interactive educational activities; sequenced and multifaceted interventions; enabling tools such as patient education programs, flow charts, and reminders; educational outreach or academic detailing; and audit and feedback to prescribers. Dr. Jean Gray reflects over the past 25 years on how there has been a transformation in the types of activities employed to improve prescribing practices in Nova Scotia. The evolution of Continuing Medical Education (CME) has resulted in the creation of the Drug Evaluation Alliance of Nova Scotia (DEANS) program, which is one exemplar of an evidence-based educational approach to improving physician prescribing in that province. Key words: Evidence-based, education, prescribing.

  17. Energy Landscape of Cellular Networks

    Science.gov (United States)

    Wang, Jin

    2008-03-01

    Cellular Networks are in general quite robust and perform their biological functions against the environmental perturbations. Progresses have been made from experimental global screenings, topological and engineering studies. However, there are so far few studies of why the network should be robust and perform biological functions from global physical perspectives. In this work, we will explore the global properties of the network from physical perspectives. The aim of this work is to develop a conceptual framework and quantitative physical methods to study the global nature of the cellular network. The main conclusion of this presentation is that we uncovered the underlying energy landscape for several small cellular networks such as MAPK signal transduction network and gene regulatory networks, from the experimentally measured or inferred inherent chemical reaction rates. The underlying dynamics of these networks can show bi-stable as well as oscillatory behavior. The global shapes of the energy landscapes of the underlying cellular networks we have studied are robust against perturbations of the kinetic rates and environmental disturbances through noise. We derived a quantitative criterion for robustness of the network function from the underlying landscape. It provides a natural explanation of the robustness and stability of the network for performing biological functions. We believe the robust landscape is a global universal property for cellular networks. We believe the robust landscape is a quantitative realization of Darwinian principle of natural selection at the cellular network level. It may provide a novel algorithm for optimizing the network connections, which is crucial for the cellular network design and synthetic biology. Our approach is general and can be applied to other cellular networks.

  18. The biophysical bases of will-less behaviours

    Directory of Open Access Journals (Sweden)

    Jose Luis ePerez Velazquez

    2012-10-01

    Full Text Available Are there distinctions at the neurophysiological level that correlate with voluntary and involuntary actions? Whereas the wide variety of involuntary behaviours (and here mostly the deviant or pathological ones will be considered will necessarily be represented at some biophysical level in nervous system activity, for after all those cellular activity patterns manifest themselves as behaviours and thus there will be a multiplicity of them, there could be some general tendencies to be discerned amongst that assortment. Collecting observations derived from neurophysiological activity associated with several pathological conditions characterised by presenting will-less actions such as Parkinson’s disease, seizures, alien hand syndrome and tics, it is proposed that a general neurophysiologic tendency of brain activity that correlates with involuntary actions is higher than normal synchrony in specific brain cell networks, depending upon the behaviour in question. Wilful, considered normal behaviour, depends on precise coordination of the collective activity in cell ensembles that may be lost, or diminished, when there are tendencies towards more than normal or aberrant synchronization of cellular activity. Hence, rapid fluctuations in synchrony is associated with normal actions and cognition while less variability in brain recordings particularly with regards to synchronization could be a signature of unconscious and deviant behaviours in general.

  19. A Solid State Pyranometer

    Directory of Open Access Journals (Sweden)

    Dumitrescu Anca Laura

    2015-12-01

    Full Text Available The construction of a solid state device-based pyranometer designated to broadband irradiance measurements is presented in this paper. The device is built on the physical basis that the temperature difference between two bodies of identical shape and external surface area, identically exposed to the incident radiation, but having different absorption and heat transfer coefficients (e.g. one body is painted white and the other is painted black, is proportional to the incident irradiance. This proportionality may be put in evidence if the two bodies consisting of identical arrays of correspondingly painted semiconductor diodes, due to the thermal behaviour of their p-n junction. It is theoretically predicted and experimentally confirmed that the voltage drop across a diode passed through a constant forward current linearly decreases with the temperature of the junction. In other words, a signal proportional to the irradiance of the light source may be obtained via conventional analog electronics. The calibration of the apparatus, as performed by means of a professional device (LP PYRA 03, indicates a good linearity.

  20. Mathematical Modeling of Cellular Metabolism.

    Science.gov (United States)

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research.

  1. Information behaviour and practice

    CERN Document Server

    Rafferty, Pauline; Baker, David

    2015-01-01

    This special issue explores information behaviour and practice in general, and specifically focuses on the implications for library and information services. Information seeking behaviour and information practice remain areas of importance in information science and librarianship, perhaps even more so in the digital age. This special issue is an opportunity to share ideas and scholarship and to explore models and methods. The papers chosen for inclusion cover a range of topics and approach them from a number of different epistemological and methodological positions demonstrating the liveliness

  2. Statics of deformable solids

    CERN Document Server

    Bisplinghoff, Raymond L; Pian, Theodore HH

    2014-01-01

    Profusely illustrated exposition of fundamentals of solid mechanics and principles of mechanics, statics, and simple statically indeterminate systems. Covers strain and stress in three-dimensional solids, elementary elasticity, energy principles in solid continuum, and more. 1965 edition.

  3. Towards a rational design of solid drug nanoparticles with optimised pharmacological properties

    Science.gov (United States)

    Martin, Phillip; Smith, Darren; Curley, Paul; McDonald, Tom; Giardiello, Marco; Liptrott, Neill; Rannard, Steve; Owen, Andrew

    2016-01-01

    Abstract Solid drug nanoparticles (SDNs) are a nanotechnology with favourable characteristics to enhance drug delivery and improve the treatment of several diseases, showing benefit for improved oral bioavailability and injectable long‐acting medicines. The physicochemical properties and composition of nanoformulations can influence the absorption, distribution, and elimination of nanoparticles; consequently, the development of nanoparticles for drug delivery should consider the potential role of nanoparticle characteristics in the definition of pharmacokinetics. The aim of this study was to investigate the pharmacological behaviour of efavirenz SDNs and the identification of optimal nanoparticle properties and composition. Seventy‐seven efavirenz SDNs were included in the analysis. Cellular accumulation was evaluated in HepG2 (hepatic) and Caco‐2 (intestinal), CEM (lymphocyte), THP1 (monocyte), and A‐THP1 (macrophage) cell lines. Apparent intestinal permeability (Papp) was measured using a monolayer of Caco‐2 cells. The Papp values were used to evaluate the potential benefit on pharmacokinetics using a physiologically based pharmacokinetic model. The generated SDNs had an enhanced intestinal permeability and accumulation in different cell lines compared to the traditional formulation of efavirenz. Nanoparticle size and excipient choice influenced efavirenz apparent permeability and cellular accumulation, and this appeared to be cell line dependent. These findings represent a valuable platform for the design of SDNs, giving an empirical background for the selection of optimal nanoparticle characteristics and composition. Understanding how nanoparticle components and physicochemical properties influence pharmacological patterns will enable the rational design of SDNs with desirable pharmacokinetics. PMID:27774308

  4. Behavioural science at work for Canada: National Research Council laboratories.

    Science.gov (United States)

    Veitch, Jennifer A

    2007-03-01

    The National Research Council is Canada's principal research and development agency. Its 20 institutes are structured to address interdisciplinary problems for industrial sectors, and to provide the necessary scientific infrastructure, such as the national science library. Behavioural scientists are active in five institutes: Biological Sciences, Biodiagnostics, Aerospace, Information Technology, and Construction. Research topics include basic cellular neuroscience, brain function, human factors in the cockpit, human-computer interaction, emergency evacuation, and indoor environment effects on occupants. Working in collaboration with NRC colleagues and with researchers from universities and industry, NRC behavioural scientists develop knowledge, designs, and applications that put technology to work for people, designed with people in mind.

  5. Behaviour Centred Design: towards an applied science of behaviour change

    Science.gov (United States)

    Aunger, Robert; Curtis, Valerie

    2016-01-01

    ABSTRACT Behaviour change has become a hot topic. We describe a new approach, Behaviour Centred Design (BCD), which encompasses a theory of change, a suite of behavioural determinants and a programme design process. The theory of change is generic, assuming that successful interventions must create a cascade of effects via environments, through brains, to behaviour and hence to the desired impact, such as improved health. Changes in behaviour are viewed as the consequence of a reinforcement learning process involving the targeting of evolved motives and changes to behaviour settings, and are produced by three types of behavioural control mechanism (automatic, motivated and executive). The implications are that interventions must create surprise, revalue behaviour and disrupt performance in target behaviour settings. We then describe a sequence of five steps required to design an intervention to change specific behaviours: Assess, Build, Create, Deliver and Evaluate. The BCD approach has been shown to change hygiene, nutrition and exercise-related behaviours and has the advantages of being applicable to product, service or institutional design, as well as being able to incorporate future developments in behaviour science. We therefore argue that BCD can become the foundation for an applied science of behaviour change. PMID:27535821

  6. Behavioural Finance: Theory and Survey

    Directory of Open Access Journals (Sweden)

    Daiva Jurevičienė

    2013-04-01

    Full Text Available The paper analyses the importance of behavioural finance theories in household decision-making process. Behavioural finance theories investigate emotional characteristics to explain subjective factors and irrational anomalies in financial markets. In this regard, behavioural theories and behavioural anomalies in the decision-making process are examined; the application opportunities in the financial market are described. The aim of investigation is to determine the basic features and slopes of behavioural finance in concordance with financial decisions of a household. The survey method was applied to ascertain financial behaviour of literate households.

  7. Phase-field simulation of formation of cellular dendrites and fine cellular structures at high growth velocities during directional solidification of Ti56Al44 alloy

    Institute of Scientific and Technical Information of China (English)

    LI Xin-zhong; GUO Jing-jie; SU Yan-qing; WU Shi-ping; FU Heng-zhi

    2005-01-01

    A phase-field model whose free energy of the solidification system derived from the Calphad thermodynamic modeling of phase diagram was used to simulate formation of cellular dendrites and fine cellular structures of Ti56Al44 alloy during directional solidification at high growth velocities. The liquid-solid phase transition of L→β was chosen. The dynamics of breakdown of initially planar interfaces into cellular dendrites and fine cellular structures were shown firstly at two growth velocities. Then the unidirectional free growths of two initial nucleations evolving to fine cellular dendrites were investigated. The tip splitting phenomenon is observed and the negative temperature gradient in the liquid represents its supercooling directional solidification. The simulation results show the realistic evolution of interfaces and microstructures and they agree with experimental one.

  8. Social Factors Influencing Household Solid Waste Minimisation

    Directory of Open Access Journals (Sweden)

    Haji Ali Nor Eeda

    2016-01-01

    Full Text Available The growth of the world’s population, coupled with increasing urbanization, and rising standards of living, have all contributed to the increase in solid waste generation. Solid waste disposal is becoming a difficult problem for many countries. Thus, efficient recycling of solid wastes is now a global concern for a sustainable solid waste management. Solid waste minimization is one of the ways of reducing the quantity of wastes for disposal. This study examines the perception of households towards solid waste minimization. 100 respondents were randomly selected from Section 7 housing area in Shah Alam city, Malaysia. Descriptive statistical technique was used in analysing the data. Findings from the study showed that respondent’s knowledge on waste minimization was above average. However, their level of knowledge as revealed further by the results is not in tandem with their attitude on waste minimization, which suggests that their attitude towards waste minimization is low. People who showed higher knowledge do not necessarily show concern or perform in solid waste minimisation. Therefore, local authorities must develop appropriate policy strategies to change the attitude and behaviour towards waste minimisation if they are to reach their statutory targets.

  9. Hierarchical Cellular Structures in High-Capacity Cellular Communication Systems

    CERN Document Server

    Jain, R K; Agrawal, N K

    2011-01-01

    In the prevailing cellular environment, it is important to provide the resources for the fluctuating traffic demand exactly in the place and at the time where and when they are needed. In this paper, we explored the ability of hierarchical cellular structures with inter layer reuse to increase the capacity of mobile communication network by applying total frequency hopping (T-FH) and adaptive frequency allocation (AFA) as a strategy to reuse the macro and micro cell resources without frequency planning in indoor pico cells [11]. The practical aspects for designing macro- micro cellular overlays in the existing big urban areas are also explained [4]. Femto cells are inducted in macro / micro / pico cells hierarchical structure to achieve the required QoS cost effectively.

  10. Behavioural Real Estate

    NARCIS (Netherlands)

    D. Salzman (Diego); R.C.J. Zwinkels (Remco)

    2013-01-01

    textabstractThe behavioural approach to decision making under uncertainty combines insights from psychology and sociology into economic decision making. It steps away from the normative homo economicus and introduces a positive approach to human decision making under uncertainty. We provide an overv

  11. Gender and Behaviour: Submissions

    African Journals Online (AJOL)

    Gender and Behaviour Ife Centre for Psychological Studies and Service. ... On page 1, type article title, author name(s), affiliation(s) address phone and fax ... the manuscript includes only original materials test has not been published and that ...

  12. Resilient behaviour of soils

    OpenAIRE

    Correia, A. Gomes; Gilett, S.

    1996-01-01

    This study examine the resilient behaviour of sands, silts and clay for different moisture conditions and various stress paths. The analysis of data from repeated load triaxial tests carried out on these recompacted soils has enable to test different models and validate their hability to predict resilient response of soils.

  13. Measuring innovative work behaviour

    NARCIS (Netherlands)

    de Jong, J.; den Hartog, D.

    2010-01-01

    Both scientists and practitioners emphasize the importance of innovative work behaviour (IWB) of individual employees for organizational success, but the measurement of IWB is still at an evolutionary stage. This article is concerned with developed a measure of IWB with four potential dimensions: th

  14. Managing Behaviour in Classrooms

    Institute of Scientific and Technical Information of China (English)

    邹柯

    2008-01-01

    Managing the class is a fussy but indispensable job for the class teacher. The relationship between teachers and students is a subtle one, which is different with each group. So it is a duty to manage their behaviour, meanwhile the teachers'skills of management appears more important.

  15. Sexual risk taking behaviour

    DEFF Research Database (Denmark)

    Buttmann, Nina; Nielsen, Ann; Munk, Christian

    2011-01-01

    Sexual habits and risky sexual behaviour strongly affect public health. Available data indicate that sexually transmitted infections are increasing in many EU countries. Changes in the epidemiology of sexually transmitted diseases across Europe are among other factors suggested to be driven by ch...

  16. Measuring innovative work behaviour

    NARCIS (Netherlands)

    de Jong, J.; den Hartog, D.

    2010-01-01

    Both scientists and practitioners emphasize the importance of innovative work behaviour (IWB) of individual employees for organizational success, but the measurement of IWB is still at an evolutionary stage. This article is concerned with developed a measure of IWB with four potential dimensions:

  17. Observing behaviour categorically

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Cheng, Allan

    1995-01-01

    In an attempt to understand the relationships and differences between the extensive amount of research within the field of bisimulation equivalences, Joyal, Nielsen, and Winskel recently proposed an abstract category-theoretic definition of bisimulation. They identify spans of morphisms satisfyin......, in fact, captures not only bisimulations but many other behavioural equivalences. We also briefly present presheaf models as an abstract model of computation....

  18. Observing behaviour categorically

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Cheng, Allan

    1995-01-01

    In an attempt to understand the relationships and differences between the extensive amount of research within the field of bisimulation equivalences, Joyal, Nielsen, and Winskel recently proposed an abstract category-theoretic definition of bisimulation. They identify spans of morphisms satisfyin......, in fact, captures not only bisimulations but many other behavioural equivalences. We also briefly present presheaf models as an abstract model of computation....

  19. Behavioural lateralisation in reindeer

    Directory of Open Access Journals (Sweden)

    Yngve Espmark

    2002-06-01

    Full Text Available Reindeer (Rangifer tarandus kept in corrals or otherwise forced to clump typically start milling in response to stressing events. This behaviour is generally considered to have an antipredator effect. An inquiry on herd behaviour, to which 35 Norwegian reindeer husbandry districts responded, showed that 32 experienced that corralled rein¬deer consistently circled leftwards, whereas the remaining three reported consistently rightward circling. Regular monitoring of a reindeer herd in central Norway over a two-year period (1993-94, and experimental studies on a fraction of the same herd, revealed the following traits. Free-ranging reindeer showed no right- or left-turning preference during grazing or browsing, but when the reindeer were driven into corrals or forced to clump in the open they invariably rotated leftwards. The circling of corralled reindeer was triggered at an average group size of 20 to 25 animals, apparently independently of the age and sex of the animals. When they dug craters in the snow to reach food, the reindeer used their left foreleg significantly more often than their right. In 23 out of 35 reindeer, the right hemisphere of the brain was heavier than the left. However, in the sample as a whole, the weights of the left and right hemispheres did not differ significantly. Lateralised behaviour in reindeer is thought to be determined by natural and stress induced asymmetries in brain structure and hormonal activity. In addition, learning is probably important for passing on the behaviour between herd members and generations. Differences in lateralised behaviour between nearby herds are thought to be related primarily to different exposure to stress and learning, whereas genetical and environmental fac¬tors (e.g. diet, age structure and sex ratio are probably more important for explaining differences between distant pop¬ulations.

  20. Prognosis of Different Cellular Generations

    Directory of Open Access Journals (Sweden)

    Preetish Ranjan

    2013-04-01

    Full Text Available Technological advancement in mobile telephony from 1G to 3G, 4G and 5G has a very axiomatic fact that made an entire world a global village. The cellular system employs a different design approach and technology that most commercial radio and television system use. In the cellular system, the service area is divided into cells and a transmitter is designed to serve an individual cell. The system seeks to make efficient use of available channels by using low-power transmitters to allow frequency reuse at a smaller distance. Maximizing the number of times each channel can be reused in a given geographical area is the key to an efficient cellular system design. During the past three decades, the world has seen significant changes in telecommunications industry. There have been some remarkable aspects to the rapid growth in wireless communications, as seen by the large expansion in mobile systems. This paper focuses on “Past, Present & Future of Cellular Telephony” and some light has been thrown upon the technologies of the cellular systems, namely 1G, 2G, 2.5G, 3G and future generations like 4G and 5G systems as well.

  1. Classifying cellular automata using grossone

    Science.gov (United States)

    D'Alotto, Louis

    2016-10-01

    This paper proposes an application of the Infinite Unit Axiom and grossone, introduced by Yaroslav Sergeyev (see [7] - [12]), to the development and classification of one and two-dimensional cellular automata. By the application of grossone, new and more precise nonarchimedean metrics on the space of definition for one and two-dimensional cellular automata are established. These new metrics allow us to do computations with infinitesimals. Hence configurations in the domain space of cellular automata can be infinitesimally close (but not equal). That is, they can agree at infinitely many places. Using the new metrics, open disks are defined and the number of points in each disk computed. The forward dynamics of a cellular automaton map are also studied by defined sets. It is also shown that using the Infinite Unit Axiom, the number of configurations that follow a given configuration, under the forward iterations of cellular automaton maps, can now be computed and hence a classification scheme developed based on this computation.

  2. Energy Sharing Framework for Microgrid-Powered Cellular Base Stations

    KAUST Repository

    Farooq, Muhammad Junaid

    2017-02-07

    Cellular base stations (BSs) are increasingly becoming equipped with renewable energy generators to reduce operational expenditures and carbon footprint of wireless communications. Moreover, advancements in the traditional electricity grid allow two-way power flow and metering that enable the integration of distributed renewable energy generators at BS sites into a microgrid. In this paper, we develop an optimized energy management framework for microgrid-connected cellular BSs that are equipped with renewable energy generators and finite battery storage to minimize energy cost. The BSs share excess renewable energy with others to reduce the dependency on the conventional electricity grid. Three cases are investigated where the renewable energy generation is unknown, perfectly known, and partially known ahead of time. For the partially known case where only the statistics of renewable energy generation are available, stochastic programming is used to achieve a conservative solution. Results show the time varying energy management behaviour of the BSs and the effect of energy sharing between them.

  3. FOSTERING ADOLESCENTS' INTERPERSONAL BEHAVIOUR: AN ...

    African Journals Online (AJOL)

    Engr E. Egbochukwu

    Training, Interpersonal Behaviour, Emotions and Gender. Introduction ... stress and lessen the risk of later emotional and behavioural problems. ... relationships, which create knowledge and develop intelligence, which in turn, gives meaning ...

  4. Glycans pattern the phase behaviour of lipid membranes

    Science.gov (United States)

    Subramaniam, Anand Bala; Guidotti, Guido; Manoharan, Vinothan N.; Stone, Howard A.

    2013-02-01

    Hydrated networks of glycans (polysaccharides)—in the form of cell walls, periplasms or gel-like matrices—are ubiquitously present adjacent to cellular plasma membranes. Yet, despite their abundance, the function of glycans in the extracellular milieu is largely unknown. Here we show that the spatial configuration of glycans controls the phase behaviour of multiphase model lipid membranes: inhomogeneous glycan networks stabilize large lipid domains at the characteristic length scale of the network, whereas homogeneous networks suppress macroscopic lipid phase separation. We also find that glycan-patterned phase separation is thermally reversible—thus indicating that the effect is thermodynamic rather than kinetic—and that phase patterning probably results from a preferential interaction of glycans with ordered lipid phases. These findings have implications for membrane-mediated transport processes, potentially rationalize long-standing observations that differentiate the behaviour of native and model membranes and may indicate an intimate coupling between cellular lipidomes and glycomes.

  5. Cellular models for Parkinson's disease.

    Science.gov (United States)

    Falkenburger, Björn H; Saridaki, Theodora; Dinter, Elisabeth

    2016-10-01

    Developing new therapeutic strategies for Parkinson's disease requires cellular models. Current models reproduce the two most salient changes found in the brains of patients with Parkinson's disease: The degeneration of dopaminergic neurons and the existence of protein aggregates consisting mainly of α-synuclein. Cultured cells offer many advantages over studying Parkinson's disease directly in patients or in animal models. At the same time, the choice of a specific cellular model entails the requirement to focus on one aspect of the disease while ignoring others. This article is intended for researchers planning to use cellular models for their studies. It describes for commonly used cell types the aspects of Parkinson's disease they model along with technical advantages and disadvantages. It might also be helpful for researchers from other fields consulting literature on cellular models of Parkinson's disease. Important models for the study of dopaminergic neuron degeneration include Lund human mesencephalic cells and primary neurons, and a case is made for the use of non-dopaminergic cells to model pathogenesis of non-motor symptoms of Parkinson's disease. With regard to α-synuclein aggregates, this article describes strategies to induce and measure aggregates with a focus on fluorescent techniques. Cellular models reproduce the two most salient changes of Parkinson's disease, the degeneration of dopaminergic neurons and the existence of α-synuclein aggregates. This article is intended for researchers planning to use cellular models for their studies. It describes for commonly used cell types and treatments the aspects of Parkinson's disease they model along with technical advantages and disadvantages. Furthermore, this article describes strategies to induce and measure aggregates with a focus on fluorescent techniques. This article is part of a special issue on Parkinson disease.

  6. Neuroendocrine control of maternal behaviour

    OpenAIRE

    Caughey, Sarah Dawn

    2011-01-01

    Maternal behaviour during the peri-partum period, albeit in differing forms, can be observed in all mammals, thus it must serve an important evolutionary purpose in enabling the successful raising of offspring. Maternal behaviour is comprised of a large suite of behaviours; in rodents these are generally defined as lactation, pup retrieval, maternal aggression and pup grooming. The maternal behaviour circuitry involves many brain regions including the hypothalamus and the limbi...

  7. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, Mai Thanh Quynh; Stürup, Stefan; Lambert, Ian Henry

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN......(-) and H2O, respectively), were included as control samples. The results indicated that B12 derivatives delivered cisplatin to both cellular cytosol and nuclei with an efficiency of one third compared to the uptake of free cisplatin cis-[Pt(II)Cl2(NH3)2]. In addition, uptake of charged B12 derivatives...

  8. Cellular basis of Alzheimer's disease.

    Science.gov (United States)

    Bali, Jitin; Halima, Saoussen Ben; Felmy, Boas; Goodger, Zoe; Zurbriggen, Sebastian; Rajendran, Lawrence

    2010-12-01

    Alzheimer's disease (AD) is the most common form of neurodegenerative disease. A characteristic feature of the disease is the presence of amyloid-β (Aβ) which either in its soluble oligomeric form or in the plaque-associated form is causally linked to neurodegeneration. Aβ peptide is liberated from the membrane-spanning -amyloid precursor protein by sequential proteolytic processing employing β- and γ-secretases. All these proteins involved in the production of Aβ peptide are membrane associated and hence, membrane trafficking and cellular compartmentalization play important roles. In this review, we summarize the key cellular events that lead to the progression of AD.

  9. The evolution of behaviour therapy and cognitive behaviour therapy.

    Science.gov (United States)

    Rachman, S

    2015-01-01

    The historical background of the development of behaviour therapy is described. It was based on the prevailing behaviourist psychology and constituted a fundamentally different approach to the causes and treatment of psychological disorders. It had a cold reception and the idea of treating the behaviour of neurotic and other patients was regarded as absurd. The opposition of the medical profession and psychoanalysts is explained. Parallel but different forms of behaviour therapy developed in the US and UK. The infusion of cognitive concepts and procedures generated a merger of behaviour therapy and cognitive therapy, cognitive behaviour therapy (CBT). The strengths and limitations of the early and current approaches are evaluated.

  10. The stability of lifestyle behaviour

    NARCIS (Netherlands)

    Mulder, M; Ranchor, AV; Sanderman, R; Bouma, J; van den Heuvel, WJA

    1998-01-01

    Background The stability of Lifestyle behaviour has been studied over a 4-year period in a sample of 1400 men in The Netherlands. The influence of both socioeconomic status and age was studied in relation to lifestyle behaviour change. Methods Lifestyle behaviour was analysed by means of index score

  11. Solid lubricants and surfaces

    CERN Document Server

    Braithwaite, E R

    1964-01-01

    Solid Lubricants and Surfaces deals with the theory and use of solid lubricants, particularly in colloidal form. Portions of this book are devoted to graphite and molybdenum disulfides, which are widely used solid lubricants in colloidal form. An extensive literature on the laboratory examination of hundreds of solids as potential lubricants is also provided in this text. Other topics discussed include the metals and solid lubricants; techniques for examining surfaces; other solid lubricants; metal shaping; and industrial uses of solid-lubricant dispersions. This publication is beneficial to e

  12. The behavioural ecology of irrational behaviours.

    Science.gov (United States)

    Huneman, Philippe; Martens, Johannes

    2017-08-17

    Natural selection is often envisaged as the ultimate cause of the apparent rationality exhibited by organisms in their specific habitat. Given the equivalence between selection and rationality as maximizing processes, one would indeed expect organisms to implement rational decision-makers. Yet, many violations of the clauses of rationality have been witnessed in various species such as starlings, hummingbirds, amoebas and honeybees. This paper attempts to interpret such discrepancies between economic rationality (defined by the main axioms of rational choice theory) and biological rationality (defined by natural selection). After having distinguished two kinds of rationality we introduce irrationality as a negation of economic rationality by biologically rational decision-makers. Focusing mainly on those instances of irrationalities that can be understood as exhibiting inconsistency in making choices, i.e. as non-conformity of a given behaviour to axioms such as transitivity or independence of irrelevant alternatives, we propose two possible families of Darwinian explanations that may account for these apparent irrationalities. First, we consider cases where natural selection may have been an indirect cause of irrationality. Second, we consider putative cases where violations of rationality axioms may have been directly favored by natural selection. Though the latter cases (prima facie) seem to clearly contradict our intuitive representation of natural selection as a process that maximizes fitness, we argue that they are actually unproblematic; for often, they can be redescribed as cases where no rationality axiom is violated, or as situations where no adaptive solution exists in the first place.

  13. Cognitive Behavioural Therapy & Training

    DEFF Research Database (Denmark)

    Spaten, Ole Michael; Hansen, Tia G. B.; Gulbrandsen, Knut Arild

    coaching module in the graduate curriculum for students of psychology is a rewarding introduction to cognitive behavioural approaches, since it allows combination of traditional lectures with “action-reflection-learning” workshops, during which students train cognitive behavioural techniques in their own......Coaching is an expanding area of professional work, and recent years have brought forward the notion of cognitive coaching (Costa, 2006; Oestrich, 2005) which adapts theory and techniques from cognitive therapy to serve self-enhancement in non-clinical populations. We suggest that a cognitive...... repertoire. The skills needed for cognitive coaching reflect all therapeutic techniques but at a less advanced psychotherapeutic level, and still prepare for future clinical work and development. In the poster, we summarise a cognitive coaching course syllabus as well as results from data collected...

  14. Cognitive Behavioural Therapy & Training

    DEFF Research Database (Denmark)

    Spaten, Ole Michael; Hansen, Tia G. B.; Gulbrandsen, Knut Arild

    Coaching is an expanding area of professional work, and recent years have brought forward the notion of cognitive coaching (Costa, 2006; Oestrich, 2005) which adapts theory and techniques from cognitive therapy to serve self-enhancement in non-clinical populations. We suggest that a cognitive...... coaching module in the graduate curriculum for students of psychology is a rewarding introduction to cognitive behavioural approaches, since it allows combination of traditional lectures with “action-reflection-learning” workshops, during which students train cognitive behavioural techniques in their own...... repertoire. The skills needed for cognitive coaching reflect all therapeutic techniques but at a less advanced psychotherapeutic level, and still prepare for future clinical work and development. In the poster, we summarise a cognitive coaching course syllabus as well as results from data collected...

  15. Cellular automaton model of precipitation/dissolution coupled with solute transport

    CERN Document Server

    Karapiperis, T

    1995-01-01

    ABSTRACT Precipitation/dissolution reactions coupled with solute transport are modelled as a cellular automaton in which solute molecules perform a random walk on a regular lattice and react according to a local probabilistic rule. Stationary solid particles dissolve with a certain probability and, provided solid is already present or the solution is saturated, solute particles have a probability to precipitate. In our simulation of the dissolution of a solid block inside uniformly flowing water we obtain solid precipitation downstream from the original solid edge, in contrast to the standard reaction-transport equations. The observed effect is the result of fluctuations in solute density and diminishes when we average over a larger ensemble. The additional precipitation of solid is accompanied by a substantial reduction in the relatively small solute concentration. The model is appropriate for the study of the rôle of intrinsic fluctuations in the presence of reaction thresholds and can be employed to inves...

  16. Redox control of cellular signalling

    NARCIS (Netherlands)

    Putker, M.

    2014-01-01

    Reactive oxygen species (ROS) are natural by-products of cellular energy production. Consequently, mammalian cells encounter them on a daily basis. Increased ROS levels are associated with the onset of cancer and accelerated ageing, and historically, ROS are therefore considered harmful molecules.

  17. On Cellular MIMO Channel Capacity

    Science.gov (United States)

    Adachi, Koichi; Adachi, Fumiyuki; Nakagawa, Masao

    To increase the transmission rate without bandwidth expansion, the multiple-input multiple-output (MIMO) technique has recently been attracting much attention. The MIMO channel capacity in a cellular system is affected by the interference from neighboring co-channel cells. In this paper, we introduce the cellular channel capacity and evaluate its outage capacity, taking into account the frequency-reuse factor, path loss exponent, standard deviation of shadowing loss, and transmission power of a base station (BS). Furthermore, we compare the cellular MIMO downlink channel capacity with those of other multi-antenna transmission techniques such as single-input multiple-output (SIMO) and space-time block coded multiple-input single-output (STBC-MISO). We show that the optimum frequency-reuse factor F that maximizes 10%-outage capacity is 3 and both 50%- and 90%-outage capacities is 1 irrespective of the type of multi-antenna transmission technique, where q%-outage capacity is defined as the channel capacity that gives an outage probability of q%. We also show that the cellular MIMO channel capacity is always higher than those of SIMO and STBC-MISO.

  18. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, MQT; Stürup, Stefan; Lambert, Ian H.;

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN(-...

  19. Psychological Factors Influencing Consumer Behaviour

    OpenAIRE

    Vainikka, Bianca

    2015-01-01

    This paper’s aim is to provide an in-depth elucidation of the many aspects that influence consumer behaviour. The study of consumer behaviour emphasizes the “why” and “how” questions involved in decision making and buying behaviour. This exciting field visits a dynamic blend of themes of consumer marketing strategies, psychology and behavioural discipline. Consumer behaviour in this day and age is highly applicable to modern society as it is an integral part of our everyday lives. This paper ...

  20. Depression during pregnancy: molecular regulations of mothers' and children's behaviour.

    Science.gov (United States)

    Pariante, Carmine M

    2014-04-01

    Depression in pregnancy (also called 'antenatal depression') is being increasingly recognized as a clinically relevant condition that affects obstetric outcome, maternal behaviour and children's future mental health. The present review focuses on the molecular mechanisms operating in utero that underlie the potential effects of antenatal depression on mothers' and children's behaviour. In particular, I discuss evidence, coming largely from animal and cellular studies, that activation of the main hormonal stress-response system, the HPA (hypothalamic-pituitary-adrenal) axis, in mothers who are depressed during pregnancy may affect maternal care as well as offspring's behaviour and future psychopathology. The evidence summarized in the present review supports the notion that preventing or treating depression in pregnancy will alleviate not only the suffering of mothers, but also the suffering of the next generation.

  1. Gene expression and behaviour in mouse models of HD.

    Science.gov (United States)

    Bowles, K R; Brooks, S P; Dunnett, S B; Jones, L

    2012-06-01

    Huntington's disease (HD) is an autosomal dominant neurodegenerative disease, resulting in expansion of the CAG repeat in exon 1 of the HTT gene. The resulting mutant huntingtin protein has been implicated in the disruption of a variety of cellular functions, including transcription. Mouse models of HD have been central to the development of our understanding of gene expression changes in this disease, and are now beginning to elucidate the relationship between gene expression and behaviour. Here, we review current mouse models of HD and their characterisation in terms of gene expression. In addition, we look at how this can inform behaviours observed in mouse models of disease. The relationship between gene expression and behaviour in mouse models of HD is important, as this will further our knowledge of disease progression and its underlying molecular events, highlight new treatment targets, and potentially provide new biomarkers for therapeutic trials. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Predicting People's Environmental Behaviour: Theory of Planned Behaviour and Model of Responsible Environmental Behaviour

    Science.gov (United States)

    Chao, Yu-Long

    2012-01-01

    Using different measures of self-reported and other-reported environmental behaviour (EB), two important theoretical models explaining EB--Hines, Hungerford and Tomera's model of responsible environmental behaviour (REB) and Ajzen's theory of planned behaviour (TPB)--were compared regarding the fit between model and data, predictive ability,…

  3. Predicting People's Environmental Behaviour: Theory of Planned Behaviour and Model of Responsible Environmental Behaviour

    Science.gov (United States)

    Chao, Yu-Long

    2012-01-01

    Using different measures of self-reported and other-reported environmental behaviour (EB), two important theoretical models explaining EB--Hines, Hungerford and Tomera's model of responsible environmental behaviour (REB) and Ajzen's theory of planned behaviour (TPB)--were compared regarding the fit between model and data, predictive ability,…

  4. CoCrMo cellular structures made by Electron Beam Melting studied by local tomography and finite element modelling

    Energy Technology Data Exchange (ETDEWEB)

    Petit, Clémence [INSA de Lyon, MATEIS CNRS UMR5510, Université de Lyon, 69621 Villeurbanne (France); Maire, Eric, E-mail: eric.maire@insa-lyon.fr [INSA de Lyon, MATEIS CNRS UMR5510, Université de Lyon, 69621 Villeurbanne (France); Meille, Sylvain; Adrien, Jérôme [INSA de Lyon, MATEIS CNRS UMR5510, Université de Lyon, 69621 Villeurbanne (France); Kurosu, Shingo; Chiba, Akihiko [Institute for Materials Research, Tohoku University, Sendai 980-0812 (Japan)

    2016-06-15

    The work focuses on the structural and mechanical characterization of Co-Cr-Mo cellular samples with cubic pore structure made by Electron Beam Melting (EBM). X-ray tomography was used to characterize the architecture of the sample. High resolution images were also obtained thanks to local tomography in which the specimen is placed close to the X-ray source. These images enabled to observe some defects due to the fabrication process: small pores in the solid phase, partially melted particles attached to the surface. Then, in situ compression tests were performed in the tomograph. The images of the deformed sample show a progressive buckling of the vertical struts leading to final fracture. The deformation initiated where the defects were present in the strut i.e. in regions with reduced local thickness. The finite element modelling confirmed the high stress concentrations of these weak points leading to the fracture of the sample. - Highlights: • CoCrMo samples fabricated by Electron Beam Melting (EBM) process are considered. • X-ray Computed Tomography is used to observe the structure of the sample. • The mechanical properties are tested thanks to an in situ test in the tomograph. • A finite element model is developed to model the mechanical behaviour.

  5. TORSIONAL DEFORMATION AND FATIGUE BEHAVIOUR OF 6061 ALUMINIUM ALLOY

    Directory of Open Access Journals (Sweden)

    marini marno

    2012-02-01

    Full Text Available Torsional deformation and fatigue behaviour of both solid and thin-walled tubular specimens were made from as-received and heat treated 6061 aluminium alloy were studied. 6061 aluminium alloy have been widely used as a candidate material in automobile, aerospace, aircraft and structural application because of their superior mechanical properties such as high strength to weight ratio, good ductility and others. The differences in cyclic deformation and fatigue behaviours between round and solid specimens where a stress gradient exist, and thin-walled tubular specimens where a uniform stress state is commonly assumed, are also discussed. Von Mises and Tresca criteria has been used to predict the monotonic and cyclic deformation curve and compared to the torsional data obtained from the experiment. The S-N curve was used to present and evaluate the fatigue life of the specimens. Through fractographic analysis, failure criteria of fracture surfaces were observed and discussed. 

  6. Solid state physics

    CERN Document Server

    Burns, Gerald

    2013-01-01

    Solid State Physics, International Edition covers the fundamentals and the advanced concepts of solid state physics. The book is comprised of 18 chapters that tackle a specific aspect of solid state physics. Chapters 1 to 3 discuss the symmetry aspects of crystalline solids, while Chapter 4 covers the application of X-rays in solid state science. Chapter 5 deals with the anisotropic character of crystals. Chapters 6 to 8 talk about the five common types of bonding in solids, while Chapters 9 and 10 cover the free electron theory and band theory. Chapters 11 and 12 discuss the effects of moveme

  7. Theoretical solid state physics

    CERN Document Server

    Haug, Albert

    2013-01-01

    Theoretical Solid State Physics, Volume 1 focuses on the study of solid state physics. The volume first takes a look at the basic concepts and structures of solid state physics, including potential energies of solids, concept and classification of solids, and crystal structure. The book then explains single-electron approximation wherein the methods for calculating energy bands; electron in the field of crystal atoms; laws of motion of the electrons in solids; and electron statistics are discussed. The text describes general forms of solutions and relationships, including collective electron i

  8. The effect of long or chopped straw on pig behaviour.

    Science.gov (United States)

    Lahrmann, H P; Oxholm, L C; Steinmetz, H; Nielsen, M B F; D'Eath, R B

    2015-05-01

    In the EU, pigs must have permanent access to manipulable materials such as straw, rope, wood, etc. Long straw can fulfil this function, but can increase labour requirements for cleaning pens, and result in problems with blocked slatted floors and slurry systems. Chopped straw might be more practical, but what is the effect on pigs' behaviour of using chopped straw instead of long straw? Commercial pigs in 1/3 slatted, 2/3 solid pens of 15 pigs were provided with either 100 g/pig per day of long straw (20 pens) or of chopped straw (19 pens). Behavioural observations were made of three focal pigs per pen (one from each of small, medium and large weight tertiles) for one full day between 0600 and 2300 h at each of ~40 and ~80 kg. The time spent rooting/investigating overall (709 s/pig per hour at 40 kg to 533 s/pig per hour at 80 kg), or directed to the straw/solid floor (497 s/pig per hour at 40 kg to 343 s/pig per hour at 80 kg), was not affected by straw length but reduced with age. Time spent investigating other pigs (83 s/pig per hour at 40 kg), the slatted floor (57 s/pig per hour) or pen fixtures (21 s/pig per hour) was not affected by age or straw length. Aggressive behaviour was infrequent, but lasted about twice as long in pens with chopped straw (2.3 s/pig per hour at 40 kg) compared with pens with long straw (1.0 s/pig per hour at 40 kg, P=0.060). There were no significant effects of straw length on tail or ear lesions, but shoulders were significantly more likely to have minor scratches with chopped straw (P=0.031), which may reflect the higher levels of aggression. Smaller pigs showed more rooting/investigatory behaviour, and in particular directed towards the straw/solid floor and the slatted floor than their larger pen-mates. Females exhibited more straw and pen fixture-directed behaviour than males. There were no effects of pig size or sex on behaviour directed towards other pigs. In summary, pigs spent similar amounts of time interacting with straw/solid

  9. Gigahertz optoacoustic imaging for cellular imaging

    Science.gov (United States)

    Rui, Min; Narashimhan, Sankar; Bost, Wolfgang; Stracke, Frank; Weiss, Eike; Lemor, Robert; Kolios, Michael C.

    2010-02-01

    Photoacoustic imaging exploits contrast mechanisms that depend on optical and thermomechanical properties of optical absorbers. The photoacoustic signal bandwidth is dictated by the absorber size and the laser pulse width. In this work we demonstrate that photoacoustic signals can be detected from micron and sub-micron particles. We anticipate applications to include cellular imaging with nanometer sized contrast agents such as gold nanoshells, nanorods, and nanocages. An existing acoustic microscopy system was used (the SASAM 1000, kibero GmbH). This platform is developed on an Olympus IX81 optical microscope with a rotating column that has an optical condenser for transmission optical microscopy and an acoustic module for the acoustic microscopy. The adapted optoacoustic module consists of a Qswitched Nd:YAG solid-state-laser (Teem Photonics, France) generating sub-nanosecond pulses. Scans were acquired of microparticles (1 μm black Toner particles) and cells. The confocal arrangement allowed high signal to noise ratio photoacoustic signals (>30 dB) to be detected at approximately 400 MHz. The particles of various sizes produced signals of different frequency content. In imaging mode, the full width half maximum (FWHM) was measured to be 3.6 μm for the 400 MHz transducer which is in general agreement theory for a 0.3 NA objective (4.3μm). Moreover, images are generated from single melanoma cells, generated by the endogenous contrast from the intracellular melanin.

  10. Ecological implications of behavioural syndromes.

    Science.gov (United States)

    Sih, Andrew; Cote, Julien; Evans, Mara; Fogarty, Sean; Pruitt, Jonathan

    2012-03-01

    Interspecific trait variation has long served as a conceptual foundation for our understanding of ecological patterns and dynamics. In particular, ecologists recognise the important role that animal behaviour plays in shaping ecological processes. An emerging area of interest in animal behaviour, the study of behavioural syndromes (animal personalities) considers how limited behavioural plasticity, as well as behavioural correlations affects an individual's fitness in diverse ecological contexts. In this article we explore how insights from the concept and study of behavioural syndromes provide fresh understanding of major issues in population ecology. We identify several general mechanisms for how population ecology phenomena can be influenced by a species or population's average behavioural type, by within-species variation in behavioural type, or by behavioural correlations across time or across ecological contexts. We note, in particular, the importance of behavioural type-dependent dispersal in spatial ecology. We then review recent literature and provide new syntheses for how these general mechanisms produce novel insights on five major issues in population ecology: (1) limits to species' distribution and abundance; (2) species interactions; (3) population dynamics; (4) relative responses to human-induced rapid environmental change; and (5) ecological invasions.

  11. Peroxisome Metabolism and Cellular Aging

    Science.gov (United States)

    Titorenko, Vladimir I.; Terlecky, Stanley R.

    2010-01-01

    The essential role of peroxisomes in fatty acid oxidation, anaplerotic metabolism, and hydrogen peroxide turnover is well established. Recent findings suggest these and other related biochemical processes governed by the organelle may also play a critical role in regulating cellular aging. The goal of this review is to summarize and integrate into a model, the evidence that peroxisome metabolism actually helps define the replicative and chronological age of a eukaryotic cell. In this model, peroxisomal reactive oxygen species (ROS) are seen as altering organelle biogenesis and function, and eliciting changes in the dynamic communication networks that exist between peroxisomes and other cellular compartments. At low levels, peroxisomal ROS activate an anti-aging program in the cell; at concentrations beyond a specific threshold, a pro-aging course is triggered. PMID:21083858

  12. Cellular proliferation and hypusine synthesis.

    Science.gov (United States)

    Torrelio, B M; Paz, M A; Gallop, P M

    1984-10-01

    Hypusine (N(-)-(4-amino-2-hydroxybutyl) lysine), a spermidine-dependent post-translational protein modification, is synthesized by various mammalian cells in culture. Experiments described in this paper demonstrated a relationship between rates of cellular growth and the synthesis of hypusine. Cells that divide at fast rates have a high rate of hypusine synthesis. In kinetic experiments, a positive relationship is evident between the rates of protein, DNA and hypusine synthesis. Cells seeded at high density, growing non-exponentially, synthesized less hypusine than logarithmically growing cells seeded at low density. Slowing the growth rate of cells by modification of the external milieu also results in a decreased rate of hypusine synthesis. These results provide additional evidence of the association of hypusine with cell proliferation in cultured cell lines and suggest a possible role for this unusual post-translational modification in the complex macromolecular events leading to cellular growth.

  13. Experimental study on the rheological behaviour of debris flow

    Directory of Open Access Journals (Sweden)

    A. Scotto di Santolo

    2010-12-01

    Full Text Available A model able to describe all the processes involved in a debris flow can be very complex owing to the sudden changing of the material that turns from solid into liquid state. The two phases of the phenomenon are analysed separately referring to soil mechanics procedures with regard to the trigger phase, and to an equivalent fluid for the post-failure phase. The present paper is devoted to show the experimental results carried out to evaluate the behaviour assumed by a pyroclastic-derived soil during the flow. A traditional fluid tool has been utilized: a standard rotational rheometer equipped with two different geometries. The soils tested belong to deposits that cover the slopes of the Campania region, Italy, often affected by debris flows. The influence of solid concentration Cv and grain size distribution was tested: the soils were destructurated, sieved and mixed with water starting from the in situ porosity. All material mixtures showed a non-Newtonian fluid behaviour with a yield stress τy that increases with a solid volumetric concentration and decreases for an increase of sand fraction. The experimental data were fitted with standard model for fluids. A simple relation between Cv and τy was obtained. The yield stress seems to be a key parameter for describing and predicting the post-failure behaviour of debris flows. These results suggest that in the field a small change in solid fraction, due to rainfall, will cause a slight decrease of the static yield stress, readily inducing a rapid flow which will stop only when the dynamic yield stress is reached, namely on a much smoother slope. This can explain the in situ observed post-failure behaviour of debris flows, which are able to flow over very long distances even on smooth slopes.

  14. Suicide and suicidal behaviour

    Science.gov (United States)

    Turecki, Gustavo; Brent, David A.

    2017-01-01

    Summary Suicide is a complex public health problem of global dimension. Suicidal behaviour (SB) shows marked differences between genders, age groups, geographic regions and socio-political realities, and variably associates with different risk factors, underscoring likely etiological heterogeneity. Although there is no effective algorithm to predict suicide in clinical practice, improved recognition and understanding of clinical, psychological, sociological, and biological factors may facilitate the detection of high-risk individuals and assist in treatment selection. Psychotherapeutic, pharmacological, or neuromodulatory treatments of mental disorders can often prevent SB; additionally, regular follow-up of suicide attempters by mental health services is key to prevent future SB. PMID:26385066

  15. Corporate Social Behaviour

    DEFF Research Database (Denmark)

    Neergaard, Peter; Rahbek Pedersen, Esben

    2003-01-01

    , human rights and environmental protection. Without a common point of reference in national regulation, managers in multinational enterprises now have to develop their own codes of corporate social behaviour. This has created a growing market for private standards within the field of environmental...... management systems, social accountability, corporate citizenship, occupational health and safety and so forth. However, both the idea of government regulation and the literature acclaiming corporate self-regulation should be met with some scepticism. This paper offers a short assessment of the potentials...

  16. Shear Thickening Behaviour of Composite Propellant Suspension under Oscillatory Shear

    Directory of Open Access Journals (Sweden)

    D. Singh

    2016-04-01

    Full Text Available Composite propellant suspensions consist of highly filled polymeric system wherein solid particles of different sizes and shapes are dispersed in a polymeric matrix. The rheological behaviour of a propellant suspension is characterised by viscoplasticity and shear rate and time dependant viscosity. The behaviour of composite propellant suspension has been studied under amplitude sweep test where tests were performed by continuously varying strain amplitude (strain in %, γ by keeping the frequency and temperature constant and results are plotted in terms of log γ (strain amplitude vs logGʹ and logGʺ (Storage modulus and loss modulus, respectively. It is clear from amplitude sweep test that dynamic moduli and complex viscosity show marked increase at critical strain amplitude after a plateau region, infering a shear thickening behaviour.

  17. Poromechanical behaviour of hardened cement paste under isotropic loading

    CERN Document Server

    Ghabezloo, Siavash; Guédon, Sylvine; Martineau, Francçois; Saint-Marc, Jérémie

    2008-01-01

    The poromechanical behaviour of hardened cement paste under isotropic loading is studied on the basis of an experimental testing program of drained, undrained and unjacketed compression tests. The macroscopic behaviour of the material is described in the framework of the mechanics of porous media. The poroelastic parameters of the material are determined and the effect of stress and pore pressure on them is evaluated. Appropriate effective stress laws which control the evolution of total volume, pore volume, solid volume, porosity and drained bulk modulus are discussed. A phenomenon of degradation of elastic properties is observed in the test results. The microscopic observations showed that this degradation is caused by the microcracking of the material under isotropic loading. The good compatibility and the consistency of the obtained poromechanical parameters demonstrate that the behaviour of the hardened cement paste can be indeed described within the framework of the theory of porous media.

  18. Identification of Nonstationary Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    AndrewI.Adamatzky

    1992-01-01

    The principal feature of nonstationary cellular automata(NCA) is that a local transitiol rule of each cell is changed at each time step depending on neighborhood configuration at previous time step.The identification problem for NCA is extraction of local transition rules and the establishment of mechanism for changing these rules using sequence of NCA configurations.We present serial and parallel algorithms for identification of NCA.

  19. CELLULAR INTERACTIONS MEDIATED BY GLYCONECTIDS

    OpenAIRE

    Popescu, O.; Sumanovski, L. T.; I. Checiu; Elisabeta Popescu; G. N. Misevic

    1999-01-01

    Cellular interactions involve many types of cell surface molecules and operate via homophilic and/or heterophilic protein-protein and protein-carbohydrate binding. Our investigations in different model-systems (marine invertebrates and mammals) have provided direct evidence that a novel class of primordial proteoglycans, named by us gliconectins, can mediate cell adhesion via a new alternative molecular mechanism of polyvalent carbohydrate-carbohydrate binding. Biochemical characterization of...

  20. Stochastic Nature in Cellular Processes

    Institute of Scientific and Technical Information of China (English)

    刘波; 刘圣君; 王祺; 晏世伟; 耿轶钊; SAKATA Fumihiko; GAO Xing-Fa

    2011-01-01

    The importance of stochasticity in cellular processes is increasingly recognized in both theoretical and experimental studies. General features of stochasticity in gene regulation and expression are briefly reviewed in this article, which include the main experimental phenomena, classification, quantization and regulation of noises. The correlation and transmission of noise in cascade networks are analyzed further and the stochastic simulation methods that can capture effects of intrinsic and extrinsic noise are described.

  1. Glycosylation regulates prestin cellular activity.

    Science.gov (United States)

    Rajagopalan, Lavanya; Organ-Darling, Louise E; Liu, Haiying; Davidson, Amy L; Raphael, Robert M; Brownell, William E; Pereira, Fred A

    2010-03-01

    Glycosylation is a common post-translational modification of proteins and is implicated in a variety of cellular functions including protein folding, degradation, sorting and trafficking, and membrane protein recycling. The membrane protein prestin is an essential component of the membrane-based motor driving electromotility changes (electromotility) in the outer hair cell (OHC), a central process in auditory transduction. Prestin was earlier identified to possess two N-glycosylation sites (N163, N166) that, when mutated, marginally affect prestin nonlinear capacitance (NLC) function in cultured cells. Here, we show that the double mutant prestin(NN163/166AA) is not glycosylated and shows the expected NLC properties in the untreated and cholesterol-depleted HEK 293 cell model. In addition, unlike WT prestin that readily forms oligomers, prestin(NN163/166AA) is enriched as monomers and more mobile in the plasma membrane, suggesting that oligomerization of prestin is dependent on glycosylation but is not essential for the generation of NLC in HEK 293 cells. However, in the presence of increased membrane cholesterol, unlike the hyperpolarizing shift in NLC seen with WT prestin, cells expressing prestin(NN163/166AA) exhibit a linear capacitance function. In an attempt to explain this finding, we discovered that both WT prestin and prestin(NN163/166AA) participate in cholesterol-dependent cellular trafficking. In contrast to WT prestin, prestin(NN163/166AA) shows a significant cholesterol-dependent decrease in cell-surface expression, which may explain the loss of NLC function. Based on our observations, we conclude that glycosylation regulates self-association and cellular trafficking of prestin(NN163/166AA). These observations are the first to implicate a regulatory role for cellular trafficking and sorting in prestin function. We speculate that the cholesterol regulation of prestin occurs through localization to and internalization from membrane microdomains by

  2. Cellular fiber–reinforced concrete

    OpenAIRE

    Isachenko S.; Kodzoev M.

    2016-01-01

    Methods disperse reinforcement of concrete matrix using polypropylene, glass, basalt and metal fibers allows to make the construction of complex configuration, solve the problem of frost products. Dispersed reinforcement reduces the overall weight of the structures. The fiber replaces the secondary reinforcement, reducing the volume of use of structural steel reinforcement. Cellular Fiber concretes are characterized by high-performance properties, especially increased bending strength and...

  3. A Local Composition Model for Paraffinic Solid Solutions

    DEFF Research Database (Denmark)

    Coutinho, A.P. João; Knudsen, Kim; Andersen, Simon Ivar

    1996-01-01

    The description of the solid-phase non-ideality remains the main obstacle in modelling the solid-liquid equilibrium of hydrocarbons. A theoretical model, based on the local composition concept, is developed for the orthorhombic phase of n-alkanes and tested against experimental data for binary sy...... systems. It is shown that it can adequately predict the experimental phase behaviour of paraffinic mixtures. This work extends the applicability of local composition models to the solid phase. Copyright (C) 1996 Elsevier Science Ltd....

  4. Progress of cellular dedifferentiation research

    Institute of Scientific and Technical Information of China (English)

    LIU Hu-xian; HU Da-hai; JIA Chi-yu; FU Xiao-bing

    2006-01-01

    Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans,dedifferentiation is often associated with carcinogenesis.The study of cellular dedifferentiation in animals,particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable,convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.

  5. The insect cellular immune response

    Institute of Scientific and Technical Information of China (English)

    Michael R. Strand

    2008-01-01

    The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. This review summarizes current understanding of the cellular immune response. Insects produce several terminally differentiated types of hemocytes that are distinguished by morphology, molecular and antigenic markers, and function. The differentiated hemocytes that circulate in larval or nymphal stage insects arise from two sources: progenitor cells produced during embryogenesis and mesodermally derived hematopoietic organs. Regulation of hematopoiesis and hemocyte differentiation also involves several different signaling pathways. Phagocytosis and encapsulation require that hemocytes first recognize a given target as foreign followed by activation of downstream signaling and effector responses. A number of humoral and cellular receptors have been identified that recognize different microbes and multicellular parasites. In turn, activation of these receptors stimulates a number of signaling pathways that regulate different hemocyte functions. Recent studies also identify hemocytes as important sources of a number of humoral effector molecules required for killing different foreign invaders.

  6. [Cellular phones and public health].

    Science.gov (United States)

    Leventhal, Alex; Karsenty, Eric; Sadetzki, Siegal

    2004-08-01

    The increased use of mobile cellular phone by the public is associated with a wave of contradictory reports about the possible health effects, due to the exposure of the users to electromagnetic non-ionizing radiation. This article reviews the state of the art of the present knowledge concerning the biological and medical effects of exposure to cellular phones, with an emphasis on its possible carcinogenic effect. Health conditions, which have been ascribed to the use of mobile phones mainly include some types of cancer and changes of brain activity. However, the balance of evidence from available studies has not yet supported these claims. Following the recommendation of special international expert committees, the IARC (International Association for Research on Cancer) is conducting a multi-center study to determine the possible effect of cellular phone use on brain and salivary gland tumors. Israel is one of the participants of this study. The only established health effect associated with the use of such technology is an increased risk for road accidents, unrelated to the amount of radiation emitted by phone. The challenge posed by this new technology to health authorities all over the world has lead to the definition of a new principle, the so-called "prudent avoidance", used as guidelines for the definition of an adequate public health policy. The public policy in Israel has used the prudent avoidance principles, while awaiting the results of the multi-national epidemiological studies.

  7. The need for a behavioural analysis of behavioural addictions.

    Science.gov (United States)

    James, Richard J E; Tunney, Richard J

    2017-03-01

    This review discusses research on behavioural addictions (i.e. associative learning, conditioning), with reference to contemporary models of substance addiction and ongoing controversies in the behavioural addictions literature. The role of behaviour has been well explored in substance addictions and gambling but this focus is often absent in other candidate behavioural addictions. In contrast, the standard approach to behavioural addictions has been to look at individual differences, psychopathologies and biases, often translating from pathological gambling indicators. An associative model presently captures the core elements of behavioural addiction included in the DSM (gambling) and identified for further consideration (internet gaming). Importantly, gambling has a schedule of reinforcement that shows similarities and differences from other addictions. While this is more likely than not applicable to internet gaming, it is less clear whether it is so for a number of candidate behavioural addictions. Adopting an associative perspective, this paper translates from gambling to video gaming, in light of the existing debates on this matter and the nature of the distinction between these behaviours. Finally, a framework for applying an associative model to behavioural addictions is outlined, and it's application toward treatment. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Study of contact angle hysteresis using the Cellular Potts Model.

    Science.gov (United States)

    Mortazavi, Vahid; D'Souza, Roshan M; Nosonovsky, Michael

    2013-02-28

    We use the Cellular Potts Model (CPM) to study the contact angle (CA) hysteresis in multiphase (solid-liquid-vapour) systems. We simulate a droplet over the tilted patterned surface, and a bubble placed under the surface immersed in liquid. The difference between bubbles and droplets was discussed through their CA hysteresis. Dependency of CA hysteresis on the surface structure and other parameters was also investigated. This analysis allows decoupling of the 1D (pinning of the triple line) and 2D (adhesion hysteresis in the contact area) effects and provides new insight into the nature of CA hysteresis.

  9. What Are Solid Fats?

    Science.gov (United States)

    ... fatty acids. Most solid fats are high in saturated fats and/or trans fats and have less monounsaturated ... Animal products containing solid fats also contain cholesterol. Saturated fats and trans fats tend to raise "bad" (LDL) ...

  10. Predicting exercise behaviour : extending the theory of planned behaviour with implementation intentions, dispositional variables, and past behaviour

    OpenAIRE

    Rognerud, Audhild Meckelborg; Wisting, Line Norøm

    2006-01-01

    The present study investigated exercise behaviour over a six-week period in a theory of planned behaviour context, extended with implementation intentions, dispositional variables, and past behaviour. Two waves of questionnaires were used to measure behavioural intention, perceived behavioural control, past behaviour, and three dispositional variables, that is optimism, self-efficacy and action-orientation, as well as actual performance of exercise behaviour. Implementation intentions were ma...

  11. Inclusive Education: Teachers' Intentions and Behaviour Analysed from the Viewpoint of the Theory of Planned Behaviour

    Science.gov (United States)

    Yan, Zi; Sin, Kuen-fung

    2014-01-01

    The theory of planned behaviour (TPB) claims that behaviour can be predicted by behavioural intention and perceived behavioural control, while behavioural intention is a function of attitude towards the behaviour, subjective norm, and perceived behavioural control. This study aims at providing explanation and prediction of teachers' inclusive…

  12. Inclusive Education: Teachers' Intentions and Behaviour Analysed from the Viewpoint of the Theory of Planned Behaviour

    Science.gov (United States)

    Yan, Zi; Sin, Kuen-fung

    2014-01-01

    The theory of planned behaviour (TPB) claims that behaviour can be predicted by behavioural intention and perceived behavioural control, while behavioural intention is a function of attitude towards the behaviour, subjective norm, and perceived behavioural control. This study aims at providing explanation and prediction of teachers' inclusive…

  13. Responding to unprofessional behaviours.

    Science.gov (United States)

    Worthington, Roger; Hays, Richard

    2012-04-01

    Medical educators sometimes have to respond to inappropriate behaviours from doctors in training that have the potential to endanger their future careers and affect the safety and well-being of their patients. The authors led workshops at international meetings using case-based discussion and plenary wrap-ups to reinforce and share the learning outcomes. This paper summarises key points of difference and common themes about how to manage challenging professional behaviours presented by doctors in training that may be of value to tutors and clinical educators. Although the problems encountered had elements in common, experiences varied between countries, schools and programmes as regards processes, procedures and thresholds for launching an investigation. Whereas variations are not unexpected it is important to consider the context and background against which decisions are made. Appropriate responses must take account of professional, legal and ethical guidelines, where they exist. Major inconsistencies in hearings and investigations may not be in anyone's best interests: fairness is core to most notions of justice, whether from the perspective of a doctor in training, clinical educator or member of the public. Therefore, schools and programmes need to take this into account when reviewing processes and procedures. Although the career of a doctor in training is important, it is not the only consideration. If systems fail the public has a right to be concerned, and striving to ensure that medical students graduate to become safe, professional doctors is something of concern to all clinical educators. © Blackwell Publishing Ltd 2012.

  14. Driver behaviour at roadworks.

    Science.gov (United States)

    Walker, Guy; Calvert, Malcolm

    2015-11-01

    There is an incompatibility between how transport engineers think drivers behave in roadworks and how they actually behave. As a result of this incompatibility we are losing approximately a lane's worth of capacity in addition to those closed by the roadworks themselves. The problem would have little significance were it not for the fact a lane of motorway costs approx. £30 m per mile to construct and £43 k a year to maintain, and that many more roadworks are planned as infrastructure constructed 40 or 50 years previously reaches a critical stage in its lifecycle. Given current traffic volumes, and the sensitivity of road networks to congestion, the effects of roadworks need to be accurately assessed. To do this requires a new ergonomic approach. A large-scale observational study of real traffic conditions was used to identify the issues and impacts, which were then mapped to the ergonomic knowledge-base on driver behaviour, and combined to developed practical guidelines to help in modelling future roadworks scenarios with greater behavioural accuracy. Also stemming from the work are novel directions for the future ergonomic design of roadworks themselves.

  15. REM sleep Behaviour Disorder.

    Science.gov (United States)

    Ferini-Strambi, Luigi; Rinaldi, Fabrizio; Giora, Enrico; Marelli, Sara; Galbiati, Andrea

    2016-01-01

    Rapid Eye Movement (REM) sleep Behaviour Disorder (RBD) is a REM sleep parasomnia characterized by loss of the muscle atonia that typically occurs during REM sleep, therefore allowing patients to act out their dreams. RBD manifests itself clinically as a violent behaviour occurring during the night, and is detected at the polysomnography by phasic and/or tonic muscle activity on the electromyography channel. In absence of neurological signs or central nervous system lesions, RBD is defined as idiopathic. Nevertheless, in a large number of cases the development of neurodegenerative diseases in RBD patients has been described, with the duration of the follow-up representing a fundamental aspect. A growing number of clinical, neurophysiologic and neuropsychological studies aimed to detect early markers of neurodegenerative dysfunction in RBD patients. Anyway, the evidence of impaired cortical activity, subtle neurocognitive dysfunction, olfactory and autonomic impairment and neuroimaging brain changes in RBD patients is challenging the concept of an idiopathic form of RBD, supporting the idea of RBD as an early manifestation of a more complex neurodegenerative process.

  16. Solid-state autocatalysis and oscillatory reactions in silicate glass systems

    DEFF Research Database (Denmark)

    Canning, John; Sørensen, Henrik Rokkjær; Kristensen, Martin

    2006-01-01

    We report the first demonstration of autocatalysis and oscillatory behaviour in the solid-state where no decomposition process is involved. Our material system is solid-state silica glass impregnated with hydrogen. It is at the heart of photosensitivity in glass-based optical waveguides and devic...... is carried out optically, opening up a new approach to characterisation of such catalytic processes generally....

  17. Solid-state optical properties of the methyl-exopyridine-anthracene rotaxane

    NARCIS (Netherlands)

    Gadret, Gregory; Zamboni, Roberto; Schouwink, Peter; Mahrt, Rainer F.; Thies, Jens; Loontjens, Ton; Leigh, David A.

    2001-01-01

    Photophysical properties in the solid state of both, an anthracene grafted rotaxane and the corresponding thread are studied. The thread in liquid and solid states as well as the rotaxane in the liquid phase exhibit only the usual anthracene-like photoluminescence (PL) behaviour, while the rotaxane

  18. Tetraphenylborate Solids Stability Tests

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.D. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-06-25

    Tetraphenylborate solids are a potentially large source of benzene in the slurries produced in the In-Tank Precipitation (ITP) process. The stability of the solids is an important consideration in the safety analysis of the process and we desire an understanding of the factors that influence the rate of conversion of the solids to benzene. This report discusses current testing of the stability of tetraphenylborate solids.

  19. Laser cooling of solids

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard I [Los Alamos National Laboratory; Sheik-bahae, Mansoor [UNM

    2008-01-01

    We present an overview of solid-state optical refrigeration also known as laser cooling in solids by fluorescence upconversion. The idea of cooling a solid-state optical material by simply shining a laser beam onto it may sound counter intuitive but is rapidly becoming a promising technology for future cryocooler. We chart the evolution of this science in rare-earth doped solids and semiconductors.

  20. Cellular communications a comprehensive and practical guide

    CERN Document Server

    Tripathi, Nishith

    2014-01-01

    Even as newer cellular technologies and standards emerge, many of the fundamental principles and the components of the cellular network remain the same. Presenting a simple yet comprehensive view of cellular communications technologies, Cellular Communications provides an end-to-end perspective of cellular operations, ranging from physical layer details to call set-up and from the radio network to the core network. This self-contained source forpractitioners and students represents a comprehensive survey of the fundamentals of cellular communications and the landscape of commercially deployed

  1. Solid State Division

    Energy Technology Data Exchange (ETDEWEB)

    Green, P.H.; Watson, D.M. (eds.)

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)

  2. The origin of cellular life

    Science.gov (United States)

    Ingber, D. E.

    2000-01-01

    This essay presents a scenario of the origin of life that is based on analysis of biological architecture and mechanical design at the microstructural level. My thesis is that the same architectural and energetic constraints that shape cells today also guided the evolution of the first cells and that the molecular scaffolds that support solid-phase biochemistry in modern cells represent living microfossils of past life forms. This concept emerged from the discovery that cells mechanically stabilize themselves using tensegrity architecture and that these same building rules guide hierarchical self-assembly at all size scales (Sci. Amer 278:48-57;1998). When combined with other fundamental design principles (e.g., energy minimization, topological constraints, structural hierarchies, autocatalytic sets, solid-state biochemistry), tensegrity provides a physical basis to explain how atomic and molecular elements progressively self-assembled to create hierarchical structures with increasingly complex functions, including living cells that can self-reproduce.

  3. Consumer behaviour regarding energy products

    National Research Council Canada - National Science Library

    Evelina Gradinaru; Lorant Bucs; Gabriel Bratucu

    2016-01-01

    ... challenge if one considers achieving them sustainably. That being said, the present paper gives emphasis to some theoretical and practical information regarding the consumer behaviour regarding energy products...

  4. Sexual behaviour in young people.

    Science.gov (United States)

    Gerressu, Makeda; Stephenson, Judith M

    2008-02-01

    The purpose of this review was to synthesize major research findings in relation to young people and sexual behaviour from the period 2006-2007. We found several key reviews that advance knowledge in the field of young people and sexual behaviour, including observational studies, both qualitative and quantitative, and intervention studies designed to reduce sexual transmission of HIV in both developed and developing countries. Other reviews focused on same-sex behaviours, victimization within relationships, HIV infection/sexually transmitted infection in travellers, prevention of HIV/sexually transmitted infection and the determinants of sexual behaviour in young people. Powerful and consistent forces sustain gender differences in sexual behaviour. The design of interventions to reduce sexual risk behaviour should take account of these forces that help explain young people's sexual behaviour. Knowledge about the kind of interventions that reduce risk behaviour and should be implemented has improved, although the impact on health outcomes such as pregnancy and HIV/sexually transmitted infection is often uncertain. Effective school sex education needs to be part of much broader strategies to improve sexual health, and there is an urgent need for better evaluation of interventions, especially community interventions. Further longitudinal studies are needed to provide insight into the development of relationships and sexual behaviour as well as the course of acculturation.

  5. Interplay between product characteristics, oral physiology and texture perception of cellular brittle foods

    NARCIS (Netherlands)

    Vliet, van T.; Primo Martin, C.

    2011-01-01

    Hard solid foods encompass a large variety of dry products as well as products with high water content. Most of these foods have a cellular structure, which is generally characterized by connected fairly rigid cell walls, enclosing a fluid material that may be liquid-like (fruit and vegetables) or a

  6. A symmetric, triply interlaced 3-D anionic MOF that exhibits both magnetic order and SMM behaviour.

    Science.gov (United States)

    Campo, J; Falvello, L R; Forcén-Vázquez, E; Sáenz de Pipaón, C; Palacio, F; Tomás, M

    2016-11-14

    A newly prepared 3-D polymer of cobalt citrate cubanes bridged by high-spin Co(ii) centres displays both single-molecule magnet (SMM) behaviour and magnetic ordering. Triple interpenetration of the 3-D diamondoid polymers yields a crystalline solid with channels that host cations and free water molecules, with the SMM behaviour of the Co4O4 cores preserved. The octahedrally coordinated Co(ii) bridges are implicated in the onset of magnetic order at an experimentally accessible temperature.

  7. Erosion behaviour of hydro turbine steels

    Indian Academy of Sciences (India)

    Akhilesh K Chauhan; D B Goel; Satya Prakash

    2008-04-01

    The martensitic stainless steel (termed as 13/4) is currently being used for fabrication of underwater parts in hydroelectric projects. There are, however, several maintenance problems associated with the use of this steel. A nitronic steel (termed as 21–4–N) has been developed as an alternative with the specific aim of overcoming these problems. A comparative study has been made on the erosion behaviour of 13/4 and 21–4–N steels by means of solid particle impingement using gas jet. The eroded surfaces after erosion tests were analysed by scanning electron microscopy. It is observed that the 21–4–N nitronic steel possesses better resistance to erosion in comparison to 13/4 martensitic stainless steel. The austenitic matrix of the nitronic steel possesses high hardness, high tensile toughness and work hardening ability, which results in higher erosion resistance.

  8. Solid expellant plasma generator

    Science.gov (United States)

    Stone, Nobie H. (Inventor); Poe, Garrett D. (Inventor); Rood, Robert (Inventor)

    2010-01-01

    An improved solid expellant plasma generator has been developed. The plasma generator includes a support housing, an electrode rod located in the central portion of the housing, and a mass of solid expellant material that surrounds the electrode rod within the support housing. The electrode rod and the solid expellant material are made of separate materials that are selected so that the electrode and the solid expellant material decompose at the same rate when the plasma generator is ignited. This maintains a point of discharge of the plasma at the interface between the electrode and the solid expellant material.

  9. Solid state phenomena

    CERN Document Server

    Lawrance, R

    1972-01-01

    Solid State Phenomena explores the fundamentals of the structure and their influence on the properties of solids. This book is composed of five chapters that focus on the electrical and thermal conductivities of crystalline solids. Chapter 1 describes the nature of solids, particularly metals and crystalline materials. This chapter also presents a model to evaluate crystal structure, the forces between atom pairs, and the mechanism of plastic and elastic deformation. Chapter 2 demonstrates random vibrations of atoms in a solid using a one-dimensional array, while Chapter 3 examines the resista

  10. CHARACTERIZATION OF SOLID CONES

    Institute of Scientific and Technical Information of China (English)

    Qiu Jinghui

    2008-01-01

    The author gives a dual characterization of solid cones in locally convex spaces.From this the author obtains some criteria for judging convex cones to be solid in various inds of locally convex spaces. Using a general expression of the interior of a solid cone,the author obtains a number of necessary and sufficient conditions for convex cones to be solid in the framework of Banach spaces. In particular, the author gives a dual relationship between solid cones and generalized sharp cones. The related known results are improved and extended.

  11. Cellular automaton model of crowd evacuation inspired by slime mould

    Science.gov (United States)

    Kalogeiton, V. S.; Papadopoulos, D. P.; Georgilas, I. P.; Sirakoulis, G. Ch.; Adamatzky, A. I.

    2015-04-01

    In all the living organisms, the self-preservation behaviour is almost universal. Even the most simple of living organisms, like slime mould, is typically under intense selective pressure to evolve a response to ensure their evolution and safety in the best possible way. On the other hand, evacuation of a place can be easily characterized as one of the most stressful situations for the individuals taking part on it. Taking inspiration from the slime mould behaviour, we are introducing a computational bio-inspired model crowd evacuation model. Cellular Automata (CA) were selected as a fully parallel advanced computation tool able to mimic the Physarum's behaviour. In particular, the proposed CA model takes into account while mimicking the Physarum foraging process, the food diffusion, the organism's growth, the creation of tubes for each organism, the selection of optimum tube for each human in correspondence to the crowd evacuation under study and finally, the movement of all humans at each time step towards near exit. To test the model's efficiency and robustness, several simulation scenarios were proposed both in virtual and real-life indoor environments (namely, the first floor of office building B of the Department of Electrical and Computer Engineering of Democritus University of Thrace). The proposed model is further evaluated in a purely quantitative way by comparing the simulation results with the corresponding ones from the bibliography taken by real data. The examined fundamental diagrams of velocity-density and flow-density are found in full agreement with many of the already published corresponding results proving the adequacy, the fitness and the resulting dynamics of the model. Finally, several real Physarum experiments were conducted in an archetype of the aforementioned real-life environment proving at last that the proposed model succeeded in reproducing sufficiently the Physarum's recorded behaviour derived from observation of the aforementioned

  12. Behavioural and Cognitive-Behavioural Treatments of Parasomnias.

    Science.gov (United States)

    Galbiati, Andrea; Rinaldi, Fabrizio; Giora, Enrico; Ferini-Strambi, Luigi; Marelli, Sara

    2015-01-01

    Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development. Nonpharmacological treatments therefore represent valid therapeutic choices. This paper reviews behavioural and cognitive-behavioural managements employed for parasomnias. Referring to the ICSD-3 nosology we consider, respectively, NREM parasomnias, REM parasomnias, and other parasomnias. Although the efficacy of some of these treatments is proved, in other cases their clinical evidence cannot be provided because of the small size of the samples. Due to the rarity of some parasomnias, further multicentric researches are needed in order to offer a more complete account of behavioural and cognitive-behavioural treatments efficacy.

  13. Behavioural and Cognitive-Behavioural Treatments of Parasomnias

    Directory of Open Access Journals (Sweden)

    Andrea Galbiati

    2015-01-01

    Full Text Available Parasomnias are unpleasant or undesirable behaviours or experiences that occur predominantly during or within close proximity to sleep. Pharmacological treatments of parasomnias are available, but their efficacy is established only for few disorders. Furthermore, most of these disorders tend spontaneously to remit with development. Nonpharmacological treatments therefore represent valid therapeutic choices. This paper reviews behavioural and cognitive-behavioural managements employed for parasomnias. Referring to the ICSD-3 nosology we consider, respectively, NREM parasomnias, REM parasomnias, and other parasomnias. Although the efficacy of some of these treatments is proved, in other cases their clinical evidence cannot be provided because of the small size of the samples. Due to the rarity of some parasomnias, further multicentric researches are needed in order to offer a more complete account of behavioural and cognitive-behavioural treatments efficacy.

  14. Game of Life Cellular Automata

    CERN Document Server

    Adamatzky, Andrew

    2010-01-01

    In the late 1960s, British mathematician John Conway invented a virtual mathematical machine that operates on a two-dimensional array of square cell. Each cell takes two states, live and dead. The cells' states are updated simultaneously and in discrete time. A dead cell comes to life if it has exactly three live neighbours. A live cell remains alive if two or three of its neighbours are alive, otherwise the cell dies. Conway's Game of Life became the most programmed solitary game and the most known cellular automaton. The book brings together results of forty years of study into computational

  15. Repaglinide at a cellular level

    DEFF Research Database (Denmark)

    Krogsgaard Thomsen, M; Bokvist, K; Høy, M

    2002-01-01

    To investigate the hormonal and cellular selectivity of the prandial glucose regulators, we have undertaken a series of experiments, in which we characterised the effects of repaglinide and nateglinide on ATP-sensitive potassium ion (KATP) channel activity, membrane potential and exocytosis in rat...... pancreatic alpha-cells and somatotrophs. We found a pharmacological dissociation between the actions on KATP channels and exocytosis and suggest that compounds that, unlike repaglinide, have direct stimulatory effects on exocytosis in somatotrophs and alpha- and beta-cells, such as sulphonylureas...... and nateglinide, may have a clinically undesirable general stimulatory effect on cells within the endocrine system....

  16. ING proteins in cellular senescence.

    Science.gov (United States)

    Menéndez, Camino; Abad, María; Gómez-Cabello, Daniel; Moreno, Alberto; Palmero, Ignacio

    2009-05-01

    Cellular senescence is an effective anti-tumor barrier that acts by restraining the uncontrolled proliferation of cells carrying potentially oncogenic alterations. ING proteins are putative tumor suppressor proteins functionally linked to the p53 pathway and to chromatin regulation. ING proteins exert their tumor-protective action through different types of responses. Here, we review the evidence on the participation of ING proteins, mainly ING1 and ING2, in the implementation of the senescent response. The currently available data support an important role of ING proteins as regulators of senescence, in connection with the p53 pathway and chromatin organization.

  17. Cellular automata a parallel model

    CERN Document Server

    Mazoyer, J

    1999-01-01

    Cellular automata can be viewed both as computational models and modelling systems of real processes. This volume emphasises the first aspect. In articles written by leading researchers, sophisticated massive parallel algorithms (firing squad, life, Fischer's primes recognition) are treated. Their computational power and the specific complexity classes they determine are surveyed, while some recent results in relation to chaos from a new dynamic systems point of view are also presented. Audience: This book will be of interest to specialists of theoretical computer science and the parallelism challenge.

  18. Cellular immune responses to HIV

    Science.gov (United States)

    McMichael, Andrew J.; Rowland-Jones, Sarah L.

    2001-04-01

    The cellular immune response to the human immunodeficiency virus, mediated by T lymphocytes, seems strong but fails to control the infection completely. In most virus infections, T cells either eliminate the virus or suppress it indefinitely as a harmless, persisting infection. But the human immunodeficiency virus undermines this control by infecting key immune cells, thereby impairing the response of both the infected CD4+ T cells and the uninfected CD8+ T cells. The failure of the latter to function efficiently facilitates the escape of virus from immune control and the collapse of the whole immune system.

  19. Effects of physicochemical properties of zinc oxide nanoparticles on cellular uptake

    Science.gov (United States)

    Yu, J.; Baek, M.; Chung, H. E.; Choi, S. J.

    2011-07-01

    Zinc oxide (ZnO) nanoparticles have been used as a source of zinc, an essential trace element in food industry and also widely applied to various cosmetic products. However, there are few researches demonstrating that the cellular uptake behaviours of ZnO with respect to the physicochemical characteristics such as particle size and surface charge in human cells. In this study, we evaluated the cellular uptake of ZnO with two different sizes (20 and 70 nm) and different charges (positive and negative). Human lung epithelial cells were exposed to ZnO for a given time, and then the uptake amount of ZnO was measured with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results showed that the smaller sized ZnO could more easily enter the cells than the larger sized ZnO. In terms of surface charge, positively charged ZnO showed high cellular uptake compared to ZnO with negative charge. The internalization pathway of positively charged ZnO nanoparticles was determined to be primarily related to the energy-dependent endocytosis. It is, therefore, concluded that the particle size and surface charge of ZnO nanoparticles are critical factors influencing on their cellular uptake. Understanding the cellular uptake behaviours of nanoparticles with respect to physicochemical properties may be important to predict their toxicity potential on human.

  20. Synchrony of plant cellular circadian clocks with heterogeneous properties under light/dark cycles.

    Science.gov (United States)

    Okada, Masaaki; Muranaka, Tomoaki; Ito, Shogo; Oyama, Tokitaka

    2017-03-22

    Individual cells in a plant can work independently as circadian clocks, and their properties are the basis of various circadian phenomena. The behaviour of individual cellular clocks in Lemna gibba was orderly under 24-h light/dark cycles despite their heterogeneous free-running periods (FRPs). Here, we reveal the entrainment habits of heterogeneous cellular clocks using non-24-h light/dark cycles (T-cycles). The cellular rhythms of AtCCA1::LUC under T = 16 h cycles showed heterogeneous entrainment that was associated with their heterogeneous FRPs. Under T = 12 h cycles, most cells showed rhythms having ~24-h periods. This suggested that the lower limit of entrainment to the light/dark cycles of heterogeneous cellular circadian clocks is set to a period longer than 12 h, which enables them to be synchronous under ~24-h daily cycles without being perturbed by short light/dark cycles. The entrainment habits of individual cellular clocks are likely to be the basis of the circadian behaviour of plant under the natural day-night cycle with noisy environmental fluctuations. We further suggest that modifications of EARLY FLOWERING3 (ELF3) in individual cells deviate the entrainability to shorter T-cycles possibly by altering both the FRPs and light responsiveness.

  1. Solids fluidizer-injector

    Science.gov (United States)

    Bulicz, T.R.

    1990-04-17

    An apparatus and process are described for fluidizing solid particles by causing rotary motion of the solid particles in a fluidizing chamber by a plurality of rotating projections extending from a rotatable cylinder end wall interacting with a plurality of fixed projections extending from an opposite fixed end wall and passing the solid particles through a radial feed orifice open to the solids fluidizing chamber on one side and a solid particle utilization device on the other side. The apparatus and process are particularly suited for obtaining intermittent feeding with continual solids supply to the fluidizing chamber. The apparatus and process are suitable for injecting solid particles, such as coal, to an internal combustion engine. 3 figs.

  2. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio

    2011-01-01

    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  3. Internet user behaviour

    Directory of Open Access Journals (Sweden)

    Radbâță, A.

    2011-01-01

    Full Text Available Internet is a useful tool for everybody in a technologically advanced world. As Internet appears and develops, it creates a totally new network environment. The development of commerce on the Internet based on virtual communities has become one of the most successful business models in the world. After analyzing the concept of internet, the e-commerce market and its marketing mix and the benefits and limitations of the Internet, we have presented a few studies on Internet user behaviour. Furthermore, the paper looks at a representative sample of Romanian internet users. The results reveal that the Romanians are using the Internet especially for information gathering, e-mail, entertainment and social networking.

  4. 5G Ultra-Dense Cellular Networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Wang, Cheng-xiang; Han, Tao

    2015-01-01

    Traditional ultra-dense wireless networks are recommended as a complement for cellular networks and are deployed in partial areas, such as hotspot and indoor scenarios. Based on the massive multiple-input multi-output (MIMO) antennas and the millimeter wavecommunication technologies, the 5G ultra-dense cellular network is proposed to deploy in overall cellular scenarios. Moreover, a distribution network architecture is presented for 5G ultra-dense cellular networks. Furthermore, the backhaul ...

  5. Epigenetics, Behaviour, and Health

    Directory of Open Access Journals (Sweden)

    Szyf Moshe

    2008-03-01

    Full Text Available The long-term effects of behaviour and environmental exposures, particularly during childhood, on health outcomes are well documented. Particularly thought provoking is the notion that exposures to different social environments have a long-lasting impact on human physical health. However, the mechanisms mediating the effects of the environment are still unclear. In the last decade, the main focus of attention was the genome, and interindividual genetic polymorphisms were sought after as the principal basis for susceptibility to disease. However, it is becoming clear that recent dramatic increases in the incidence of certain human pathologies, such as asthma and type 2 diabetes, cannot be explained just on the basis of a genetic drift. It is therefore extremely important to unravel the molecular links between the "environmental" exposure, which is believed to be behind this emerging incidence in certain human pathologies, and the disease's molecular mechanisms. Although it is clear that most human pathologies involve long-term changes in gene function, these might be caused by mechanisms other than changes in the deoxyribonucleic acid (DNA sequence. The genome is programmed by the epigenome, which is composed of chromatin and a covalent modification of DNA by methylation. It is postulated here that "epigenetic" mechanisms mediate the effects of behavioural and environmental exposures early in life, as well as lifelong environmental exposures and the susceptibility to disease later in life. In contrast to genetic sequence differences, epigenetic aberrations are potentially reversible, raising the hope for interventions that will be able to reverse deleterious epigenetic programming.

  6. Cellular Fibroma of the Ovary with Multiloculated Macroscopic Characteristics: Case Report

    Directory of Open Access Journals (Sweden)

    Sheila Jorge Adad

    2012-01-01

    Full Text Available Ovarian fibroma is the commonest benign tumor of the ovarian stroma. The cellular subtype accounts for around 10% of ovarian fibromatous tumors. The cellular fibroma is a tumor of uncertain malignant potential that may recur or be associated with peritoneal implants. Usually these are solid tumors, sometimes with small areas of cystic degeneration. This case is reported to highlight an unusual feature for an ovarian fibroma: the tumor was predominantly cystic with a small solid part; the multiple cavities contents consisted of viscous liquid that solidified under room temperature. The multiloculated cysts, the mucinous contents, and the solid areas simulated a borderline mucinous ovarian tumor on both CT scan and gross pathologic examination.

  7. Applying statistics in behavioural research

    NARCIS (Netherlands)

    Ellis, J.L.

    2016-01-01

    Applying Statistics in Behavioural Research is written for undergraduate students in the behavioural sciences, such as Psychology, Pedagogy, Sociology and Ethology. The topics range from basic techniques, like correlation and t-tests, to moderately advanced analyses, like multiple regression and MAN

  8. Candidate genes for behavioural ecology

    NARCIS (Netherlands)

    Fitzpatrick, M.J.; Ben-Sahar, Y.; Smid, H.M.; Vet, L.E.M.; Robinson, G.E.; Sokolowski, M.B.

    2005-01-01

    In spite of millions of years of evolutionary divergence, the conservation of gene function is common across distant lineages. As such, genes that are known to influence behaviour in one organism are likely to influence similar behaviours in other organisms. Recent studies of the evolution of behavi

  9. Reconsidering the sedentary behaviour paradigm.

    Directory of Open Access Journals (Sweden)

    Carol Maher

    Full Text Available AIMS: Recent literature has posed sedentary behaviour as an independent entity to physical inactivity. This study investigated whether associations between sedentary behaviour and cardio-metabolic biomarkers remain when analyses are adjusted for total physical activity. METHODS: Cross-sectional analyses were undertaken on 4,618 adults from the 2003/04 and 2005/06 U.S. National Health and Nutrition Examination Survey. Minutes of sedentary behaviour and moderate-to-vigorous physical activity (MVPA, and total physical activity (total daily accelerometer counts minus counts accrued during sedentary minutes were determined from accelerometry. Associations between sedentary behaviour and cardio-metabolic biomarkers were examined using linear regression. RESULTS: Results showed that sedentary behaviour was detrimentally associated with 8/11 cardio-metabolic biomarkers when adjusted for MVPA. However, when adjusted for total physical activity, the associations effectively disappeared, except for C-reactive protein, which showed a very small, favourable association (β = -0.06 and triglycerides, which showed a very small, detrimental association (β = 0.04. Standardised betas suggested that total physical activity was consistently, favourably associated with cardio-metabolic biomarkers (9/11 biomarkers, standardized β = 0.08-0.30 while sedentary behaviour was detrimentally associated with just 1 biomarker (standardized β = 0.12. CONCLUSION: There is virtually no association between sedentary behaviour and cardio-metabolic biomarkers once analyses are adjusted for total physical activity. This suggests that sedentary behaviour may not have health effects independent of physical activity.

  10. Infant Predictors of Behavioural Inhibition

    Science.gov (United States)

    Moehler, Eva; Kagan, Jerome; Oelkers-Ax, Rieke; Brunner, Romuald; Poustka, Luise; Haffner, Johann; Resch, Franz

    2008-01-01

    Behavioural inhibition in the second year of life is a hypothesized predictor for shyness, social anxiety and depression in later childhood, adolescence and even adulthood. To search for the earliest indicators of this fundamental temperamental trait, this study examined whether behavioural characteristics in early infancy can predict behavioural…

  11. Cellular functions of the microprocessor.

    Science.gov (United States)

    Macias, Sara; Cordiner, Ross A; Cáceres, Javier F

    2013-08-01

    The microprocessor is a complex comprising the RNase III enzyme Drosha and the double-stranded RNA-binding protein DGCR8 (DiGeorge syndrome critical region 8 gene) that catalyses the nuclear step of miRNA (microRNA) biogenesis. DGCR8 recognizes the RNA substrate, whereas Drosha functions as an endonuclease. Recent global analyses of microprocessor and Dicer proteins have suggested novel functions for these components independent of their role in miRNA biogenesis. A HITS-CLIP (high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation) experiment designed to identify novel substrates of the microprocessor revealed that this complex binds and regulates a large variety of cellular RNAs. The microprocessor-mediated cleavage of several classes of RNAs not only regulates transcript levels, but also modulates alternative splicing events, independently of miRNA function. Importantly, DGCR8 can also associate with other nucleases, suggesting the existence of alternative DGCR8 complexes that may regulate the fate of a subset of cellular RNAs. The aim of the present review is to provide an overview of the diverse functional roles of the microprocessor.

  12. Melanoma screening with cellular phones.

    Directory of Open Access Journals (Sweden)

    Cesare Massone

    Full Text Available BACKGROUND: Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases. METHODOLOGY/PRINCIPAL FINDINGS: In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria. Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively. CONCLUSIONS/SIGNIFICANCE: The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

  13. Melanoma screening with cellular phones.

    Science.gov (United States)

    Massone, Cesare; Hofmann-Wellenhof, Rainer; Ahlgrimm-Siess, Verena; Gabler, Gerald; Ebner, Christoph; Soyer, H Peter

    2007-05-30

    Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases. In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria). Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp) where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively. The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

  14. Cellular automata modelling of SEIRS

    Institute of Scientific and Technical Information of China (English)

    Liu Quan-Xing; Jin Zhen

    2005-01-01

    In this paper the SEIRS epidemic spread is analysed, and a two-dimensional probability cellular automata model for SEIRS is presented. Each cellular automation cell represents a part of the population that may be found in one of five states of individuals: susceptible, exposed (or latency), infected, immunized (or recovered) and death. Here studied are the effects of two cases on the epidemic spread. i.e. the effects of non-segregation and segregation on the latency and the infected of population. The conclusion is reached that the epidemic will persist in the case of non-segregation but it will decrease in the case of segregation. The proposed model can serve as a basis for the development of algorithms to simulate real epidemics based on real data. Last we find the density series of the exposed and the infected will fluctuate near a positive equilibrium point, when the constant for the immunized is less than its corresponding constant τ0. Our theoretical results are verified by numerical simulations.

  15. Solid-State NMR Spectroscopy for the Physical Chemistry Laboratory

    Science.gov (United States)

    Kinnun, Jacob J.; Leftin, Avigdor; Brown, Michael F.

    2013-01-01

    Solid-state nuclear magnetic resonance (NMR) spectroscopy finds growing application to inorganic and organic materials, biological samples, polymers, proteins, and cellular membranes. However, this technique is often neither included in laboratory curricula nor typically covered in undergraduate courses. On the other hand, spectroscopy and…

  16. Solid-State NMR Spectroscopy for the Physical Chemistry Laboratory

    Science.gov (United States)

    Kinnun, Jacob J.; Leftin, Avigdor; Brown, Michael F.

    2013-01-01

    Solid-state nuclear magnetic resonance (NMR) spectroscopy finds growing application to inorganic and organic materials, biological samples, polymers, proteins, and cellular membranes. However, this technique is often neither included in laboratory curricula nor typically covered in undergraduate courses. On the other hand, spectroscopy and…

  17. Propagating Instabilities in Solids

    Science.gov (United States)

    Kyriakides, Stelios

    1998-03-01

    Instability is one of the factors which limit the extent to which solids can be loaded or deformed and plays a pivotal role in the design of many structures. Such instabilities often result in localized deformation which precipitates catastrophic failure. Some materials have the capacity to recover their stiffness following a certain amount of localized deformation. This local recovery in stiffness arrests further local deformation and spreading of the instability to neighboring material becomes preferred. Under displacement controlled loading the propagation of the transition fronts can be achieved in a steady-state manner at a constant stress level known as the propagation stress. The stresses in the transition fronts joining the highly deformed zone to the intact material overcome the instability nucleation stresses and, as a result, the propagation stress is usually much lower than the stress required to nucleate the instability. The classical example of this class of material instabilities is L/"uders bands which tend to affect mild steels and other metals. Recent work has demonstrated that propagating instabilities occur in several other materials. Experimental and analytical results from four examples will be used to illustrate this point: First the evolution of L=FCders bands in mild steel strips will be revisited. The second example involves the evolution of stress induced phase transformations (austenite to martensite phases and the reverse) in a shape memory alloy under displacement controlled stretching. The third example is the crushing behavior of cellular materials such as honeycombs and foams made from metals and polymers. The fourth example involves the axial broadening/propagation of kink bands in aligned fiber/matrix composites under compression. The microstructure and, as a result, the micromechanisms governing the onset, localization, local arrest and propagation of instabilities in each of the four materials are vastly different. Despite this

  18. Measuring Thermoforming Behaviour

    Science.gov (United States)

    Michaeli, W.; Hopmann, C.; Ederleh, L.; Begemann, M.

    2011-05-01

    Thermoforming is the process of choice for manufacturing thin-gauge or large-area parts for packaging or technical applications. The process allows low-weight parts to be produced rapidly and economically from thermoplastic semi-finished products. A technical and consequently economical problem is the choice of the right material in combination with the thermoformability of the product. The prediction of thermoformability includes the aspired product features and geometry and defined wall thickness distributions, depending on the specific stretchability of the semifinished product. In practice, thermoformability is estimated by empirical tests with the particular semi-finished product using e.g. staged pyramidal moulds or model cars. With this method, it still cannot be ensured that the product can be thermoformed with the intended properties. A promising alternative is the forming simulation using finite element analysis (FEA). For the simulation, it is necessary to describe the material behaviour using defined material models and the appropriate parameters. Therefore, the stress-/strain-behaviour of the semi-finished product under defined conditions is required. There are several, entirely different measurement techniques used in industry and at research facilities. This paper compares a choice of different measurement techniques to provide an objective basis for future work and research. The semi-finished products are examined with the Membrane-Inflation-Rheometer (MIR), an equibiaxial strain rheometer. A flat sample is heated to the desired temperature in silicone oil. During the measurement, a servohydraulic linear drive advances a piston, thus displacing the hot silicone oil and inflating the specimen to form a sphere. Further measurements are carried out with the Karo IV Laboratory Stretching Machine at Brückner Maschinenbau GmbH & Co. KG, Siegsdorf, Germany. The samples are heated using hot air. During the biaxial stretching, the resulting forces at the

  19. Sexual behaviour, contraceptive practice and reproductive health ...

    African Journals Online (AJOL)

    Sexual behaviour, contraceptive practice and reproductive health outcomes among ... sexual behaviour, outcomes and care-seeking among university students in ... to collect information on their reproductive health knowledge and behaviour.

  20. Diffusion of solid fuelon a vibrating grate

    DEFF Research Database (Denmark)

    Sabelström, Hanna Katarina

    of vibrations can be incorporated into a numerical model. The chosen model approach has been to separate the gas and solid phases into two independent models related to each other through the bed porosity. By treating the bed as a porous media and using Ergun's equation for the gas flow, the numerical work...... is simplified and the computational time shortened. The vibrations are affecting the transport and mixing of the fuel and incorporated into the model through the diffusion coefficient in the conservation equation of the solid phase. Experimental work has been carried out with the aim to study the behaviour...... movement of the particles. The results show that the diffusion of the particles increases with increasing vibration amplitude and frequency and decreasing particle layer thickness. There is a significant difference in the magnitude of the diffusion coefficients for the different test set-ups, which shows...

  1. Sensing Phosphatidylserine in Cellular Membranes

    Directory of Open Access Journals (Sweden)

    Jason G. Kay

    2011-01-01

    Full Text Available Phosphatidylserine, a phospholipid with a negatively charged head-group, is an important constituent of eukaryotic cellular membranes. On the plasma membrane, rather than being evenly distributed, phosphatidylserine is found preferentially in the inner leaflet. Disruption of this asymmetry, leading to the appearance of phosphatidylserine on the surface of the cell, is known to play a central role in both apoptosis and blood clotting. Despite its importance, comparatively little is known about phosphatidylserine in cells: its precise subcellular localization, transmembrane topology and intracellular dynamics are poorly characterized. The recent development of new, genetically-encoded probes able to detect phosphatidylserine within live cells, however, is leading to a more in-depth understanding of the biology of this phospholipid. This review aims to give an overview of the current methods for phosphatidylserine detection within cells, and some of the recent realizations derived from their use.

  2. Discrete geodesics and cellular automata

    CERN Document Server

    Arrighi, Pablo

    2015-01-01

    This paper proposes a dynamical notion of discrete geodesics, understood as straightest trajectories in discretized curved spacetime. The notion is generic, as it is formulated in terms of a general deviation function, but readily specializes to metric spaces such as discretized pseudo-riemannian manifolds. It is effective: an algorithm for computing these geodesics naturally follows, which allows numerical validation---as shown by computing the perihelion shift of a Mercury-like planet. It is consistent, in the continuum limit, with the standard notion of timelike geodesics in a pseudo-riemannian manifold. Whether the algorithm fits within the framework of cellular automata is discussed at length. KEYWORDS: Discrete connection, parallel transport, general relativity, Regge calculus.

  3. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  4. Molecular, cellular, and tissue engineering

    CERN Document Server

    Bronzino, Joseph D

    2015-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering. Molecular, Cellular, and Tissue Engineering, the fourth volume of the handbook, presents material from respected scientists with diverse backgrounds in molecular biology, transport phenomena, physiological modeling, tissue engineering, stem cells, drug delivery systems, artificial organs, and personalized medicine. More than three dozen specific topics are examined, including DNA vaccines, biomimetic systems, cardiovascular dynamics, biomaterial scaffolds, cell mechanobiology, synthetic biomaterials, pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, nanobiomaterials for tissue engineering, biomedical imaging of engineered tissues, gene therapy, noninvasive targeted protein and peptide drug deliver...

  5. REGULATORY MECHANISMS OF CELLULAR RESPIRATION

    Science.gov (United States)

    Barron, E. S. Guzman; Nelson, Leonard; Ardao, Maria Isabel

    1948-01-01

    Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric chloride, p-chloromercuribenzoate, sodium arsenite, and p-carboxyphenylarsine oxide, added in small concentrations to a suspension of sea urchin sperm produced an increase in respiration. When the concentration was increased there was an inhibition. These effects are explained by postulating the presence in the cells of two kinds of sulfhydryl groups: soluble sulfhydryl groups, which regulate cellular respiration, and fixed sulfhydryl groups, present in the protein moiety of enzymes. Small concentrations of sulfhydryl reagents combine only with the first, thus producing an increase in respiration; when the concentration is increased, the fixed sulfhydryl groups are also attacked and inhibition of respiration is the consequence. Other inhibitors of cell respiration, such as cyanide and urethanes, which do not combine with —SH groups, did not stimulate respiration in small concentration. PMID:18891144

  6. Fundamental Limits to Cellular Sensing

    Science.gov (United States)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  7. Solid state video cameras

    CERN Document Server

    Cristol, Y

    2013-01-01

    Solid State Video Cameras reviews the state of the art in the field of solid-state television cameras as compiled from patent literature. Organized into 10 chapters, the book begins with the basic array types of solid-state imagers and appropriate read-out circuits and methods. Documents relating to improvement of picture quality, such as spurious signal suppression, uniformity correction, or resolution enhancement, are also cited. The last part considerssolid-state color cameras.

  8. Solid propellant rocket motor

    Science.gov (United States)

    Dowler, W. L.; Shafer, J. I.; Behm, J. W.; Strand, L. D. (Inventor)

    1973-01-01

    The characteristics of a solid propellant rocket engine with a controlled rate of thrust buildup to a desired thrust level are discussed. The engine uses a regressive burning controlled flow solid propellant igniter and a progressive burning main solid propellant charge. The igniter is capable of operating in a vacuum and sustains the burning of the propellant below its normal combustion limit until the burning propellant surface and combustion chamber pressure have increased sufficiently to provide a stable chamber pressure.

  9. Synchronization, TIGoRS, and Information Flow in Complex Systems: Dispositional Cellular Automata.

    Science.gov (United States)

    Sulis, William H

    2016-04-01

    Synchronization has a long history in physics where it refers to the phase matching of two identical oscillators. This notion has been extensively studied in physics as well as in biology, where it has been applied to such widely varying phenomena as the flashing of fireflies and firing of neurons in the brain. Human behavior, however, may be recurrent but it is not oscillatory even though many physiological systems do exhibit oscillatory tendencies. Moreover, much of human behaviour is collaborative and cooperative, where the individual behaviours may be distinct yet contemporaneous (if not simultaneous) and taken collectively express some functionality. In the context of behaviour, the important aspect is the repeated co-occurrence in time of behaviours that facilitate the propagation of information or of functionality, regardless of whether or not these behaviours are similar or identical. An example of this weaker notion of synchronization is transient induced global response synchronization (TIGoRS). Previous work has shown that TIGoRS is a ubiquitous phenomenon among complex systems, enabling them to stably parse environmental transients into salient units to which they stably respond. This leads to the notion of Sulis machines, which emergently generate a primitive linguistic structure through their dynamics. This article reviews the notion of TIGoRS and its expression in several complex systems models including tempered neural networks, driven cellular automata and cocktail party automata. The emergent linguistics of Sulis machines are discussed. A new class of complex systems model, the dispositional cellular automaton is introduced. A new metric for TIGoRS, the excess synchronization, is introduced and applied to the study of TIGoRS in dispositional cellular automata. It is shown that these automata exhibit a nonlinear synchronization response to certain perturbing transients.

  10. Developmental constraints on behavioural flexibility.

    Science.gov (United States)

    Holekamp, Kay E; Swanson, Eli M; Van Meter, Page E

    2013-05-19

    We suggest that variation in mammalian behavioural flexibility not accounted for by current socioecological models may be explained in part by developmental constraints. From our own work, we provide examples of constraints affecting variation in behavioural flexibility, not only among individuals, but also among species and higher taxonomic units. We first implicate organizational maternal effects of androgens in shaping individual differences in aggressive behaviour emitted by female spotted hyaenas throughout the lifespan. We then compare carnivores and primates with respect to their locomotor and craniofacial adaptations. We inquire whether antagonistic selection pressures on the skull might impose differential functional constraints on evolvability of skulls and brains in these two orders, thus ultimately affecting behavioural flexibility in each group. We suggest that, even when carnivores and primates would theoretically benefit from the same adaptations with respect to behavioural flexibility, carnivores may nevertheless exhibit less behavioural flexibility than primates because of constraints imposed by past adaptations in the morphology of the limbs and skull. Phylogenetic analysis consistent with this idea suggests greater evolutionary lability in relative brain size within families of primates than carnivores. Thus, consideration of developmental constraints may help elucidate variation in mammalian behavioural flexibility.

  11. Hormonal mechanisms of cooperative behaviour

    Science.gov (United States)

    Soares, Marta C.; Bshary, Redouan; Fusani, Leonida; Goymann, Wolfgang; Hau, Michaela; Hirschenhauser, Katharina; Oliveira, Rui F.

    2010-01-01

    Research on the diversity, evolution and stability of cooperative behaviour has generated a considerable body of work. As concepts simplify the real world, theoretical solutions are typically also simple. Real behaviour, in contrast, is often much more diverse. Such diversity, which is increasingly acknowledged to help in stabilizing cooperative outcomes, warrants detailed research about the proximate mechanisms underlying decision-making. Our aim here is to focus on the potential role of neuroendocrine mechanisms on the regulation of the expression of cooperative behaviour in vertebrates. We first provide a brief introduction into the neuroendocrine basis of social behaviour. We then evaluate how hormones may influence known cognitive modules that are involved in decision-making processes that may lead to cooperative behaviour. Based on this evaluation, we will discuss specific examples of how hormones may contribute to the variability of cooperative behaviour at three different levels: (i) within an individual; (ii) between individuals and (iii) between species. We hope that these ideas spur increased research on the behavioural endocrinology of cooperation. PMID:20679116

  12. Behavioural management of migraine

    Directory of Open Access Journals (Sweden)

    Helen Brown

    2012-01-01

    Full Text Available It is important to recognise that migraine is a ′biological′ and not a ′psychological′ entity. However, psychological factors can be involved in migraine in 4 different ways:- 1 Migraines can be triggered by psychological stressors; 2 Severe migraine can itself be a cause of significant psychological stress which can, in turn, exacerbate the problem; 3 Even if psychological stress is not significantly involved in the genesis of the headache, pain management techniques can help people cope with their pain more effectively; 4 Longitudinal data demonstrate a complex bidirectional association between mood disorders and migraine. Treatment of a co-existing mood disorder, for example with cognitive behavioural techniques, may therefore reduce the impact of migraine. It would thus appear logical to view medical and psychological approaches as potentially synergistic rather than mutually exclusive. Functional imaging indicates that cognition, emotions, and pain experiences change the way the brain processes pain inputs. This may provide a physiological rationale for psychological interventions in pain management. As most studies of psychological management of migraine have been relatively small and the approach often varies between clinicians, the magnitude of benefit, optimum method of delivery, and the length of intervention are uncertain.

  13. Understanding solid state physics

    CERN Document Server

    Holgate, Sharon Ann

    2009-01-01

    Where Sharon Ann Holgate has succeeded in this book is in packing it with examples of the application of solid state physics to technology. … All the basic elements of solid state physics are covered … . The range of materials is good, including as it does polymers and glasses as well as crystalline solids. In general, the style makes for easy reading. … Overall this book succeeds in showing the relevance of solid state physics to the modern world … .-Contemporary Physics, Vol. 52, No. 2, 2011I was indeed amused and inspired by the wonderful images throughout the book, carefully selected by th

  14. Sexual behaviour of Slovenian primary school pupils - youth sexual behaviour

    National Research Council Canada - National Science Library

    Brcar, Polonca

    2008-01-01

    ...) showed a statistically significant gender difference. In order to evaluate the linear effect of the independent variables on the dependent variable we used Multiple Regression and Correlation according to Ajzen's model of planned behaviour...

  15. Reverse Engineering Cellular Networks with Information Theoretic Methods

    Directory of Open Access Journals (Sweden)

    Julio R. Banga

    2013-05-01

    Full Text Available Building mathematical models of cellular networks lies at the core of systems biology. It involves, among other tasks, the reconstruction of the structure of interactions between molecular components, which is known as network inference or reverse engineering. Information theory can help in the goal of extracting as much information as possible from the available data. A large number of methods founded on these concepts have been proposed in the literature, not only in biology journals, but in a wide range of areas. Their critical comparison is difficult due to the different focuses and the adoption of different terminologies. Here we attempt to review some of the existing information theoretic methodologies for network inference, and clarify their differences. While some of these methods have achieved notable success, many challenges remain, among which we can mention dealing with incomplete measurements, noisy data, counterintuitive behaviour emerging from nonlinear relations or feedback loops, and computational burden of dealing with large data sets.

  16. Separation of Bouguer anomaly map using cellular neural network

    Science.gov (United States)

    Albora, A. Muhittin; Ucan, Osman N.; Ozmen, Atilla; Ozkan, Tulay

    2001-02-01

    In this paper, a modern image-processing technique, the Cellular Neural Network (CNN) has been firstly applied to Bouguer anomaly map of synthetic examples and then to data from the Sivas-Divrigi Akdag region. CNN is an analog parallel computing paradigm defined in space and characterized by the locality of connections between processing neurons. The behaviour of the CNN is defined by two template matrices and a template vector. We have optimised the weight coefficients of these templates using the Recurrent Perceptron Learning Algorithm (RPLA). After testing CNN performance on synthetic examples, the CNN approach has been applied to the Bouguer anomaly of Sivas-Divrigi Akdag region and the results match drilling logs done by Mineral Research and Exploration (MTA).

  17. Sensing behaviour in healthcare design

    DEFF Research Database (Denmark)

    Thorpe, Julia Rosemary; Hysse Forchhammer, Birgitte; Maier, Anja

    2017-01-01

    We are entering an era of distributed healthcare that should fit and respond to individual needs, behaviour and lifestyles. Designing such systems is a challenging task that requires continuous information about human behaviour on a large scale, for which pervasive sensing (e.g. using smartphones...... specifically on activity and location data that can easily be obtained from smartphones or wearables. We further demonstrate how these are applied in healthcare design using an example from dementia care. Comparing a current and proposed scenario exemplifies how integrating sensor-derived information about...... user behaviour can support the healthcare design goals of personalisation, adaptability and scalability, while emphasising patient quality of life....

  18. The cellular and genetic basis of olfactory responses in Caenorhabditis elegans.

    Science.gov (United States)

    Sengupta, P; Colbert, H A; Kimmel, B E; Dwyer, N; Bargmann, C I

    1993-01-01

    The small soil nematode Caenorhabditis elegans has only 302 neurons in its entire nervous system, so it is possible to analyse the functions of individual neurons in the animal's behaviour. We are using behavioural, cellular and genetic analyses of chemotactic responses to find out how olfactory behaviour patterns are generated and regulated. Single chemosensory neurons in C. elegans can recognize several different attractive odorants that are distinguished by the animal. Distinct sets of chemosensory neurons detect high and low concentrations of a single odorant. Odorant responses adapt after prolonged exposure to an odorant; this adaptation is odorant specific and reversible. Mutants with defects in odorant responses have been identified. Some genes appear to be necessary for the development or function of particular kinds of sensory neurons. Other genes have effects that suggest that they participate in odorant reception or signal transduction.

  19. Habituation of reflexive and motivated behaviour in mice with deficient BK channel function

    Directory of Open Access Journals (Sweden)

    Marei eTyplt

    2013-11-01

    Full Text Available Habituation is considered the most basic form of learning. It describes the decrease of a behavioural response to a repeated non-threatening sensory stimulus and therefore provides an important sensory filtering mechanism. While some neuronal pathways mediating habituation are well described, underlying cellular/molecular mechanisms are not yet fully understood. In general, there is an agreement that short-term and long-term habituation are based on different mechanisms. Historically, a distinction has also been made between habituation of motivated versus reflexive behaviour. In recent studies in invertebrates the large conductance voltage- and calcium-activated potassium (BK channel has been implicated to be a key player in habituation by regulating synaptic transmission. Here, we tested mice deficient for the pore forming α-subunit of the BK channel for short-term and long-term habituation of the acoustic startle reflex (reflexive behaviour and of the exploratory locomotor behaviour in the open field box (motivated behaviour. Short-term habituation of startle was completely abolished in the BK knock-out mice, whereas neither long-term habituation of startle nor habituation of motivated behaviour was affected by the BK deficiency. Our results support a highly preserved mechanism for short-term habituation of startle across species that is distinct from long-term habituation mechanisms. It also supports the notion that there are different mechanisms underlying habituation of motivated behaviour versus reflexive behaviour.

  20. Understanding individual routing behaviour.

    Science.gov (United States)

    Lima, Antonio; Stanojevic, Rade; Papagiannaki, Dina; Rodriguez, Pablo; González, Marta C

    2016-03-01

    Knowing how individuals move between places is fundamental to advance our understanding of human mobility (González et al. 2008 Nature 453, 779-782. (doi:10.1038/nature06958)), improve our urban infrastructure (Prato 2009 J. Choice Model. 2, 65-100. (doi:10.1016/S1755-5345(13)70005-8)) and drive the development of transportation systems. Current route-choice models that are used in transportation planning are based on the widely accepted assumption that people follow the minimum cost path (Wardrop 1952 Proc. Inst. Civ. Eng. 1, 325-362. (doi:10.1680/ipeds.1952.11362)), despite little empirical support. Fine-grained location traces collected by smart devices give us today an unprecedented opportunity to learn how citizens organize their travel plans into a set of routes, and how similar behaviour patterns emerge among distinct individual choices. Here we study 92 419 anonymized GPS trajectories describing the movement of personal cars over an 18-month period. We group user trips by origin-destination and we find that most drivers use a small number of routes for their routine journeys, and tend to have a preferred route for frequent trips. In contrast to the cost minimization assumption, we also find that a significant fraction of drivers' routes are not optimal. We present a spatial probability distribution that bounds the route selection space within an ellipse, having the origin and the destination as focal points, characterized by high eccentricity independent of the scale. While individual routing choices are not captured by path optimization, their spatial bounds are similar, even for trips performed by distinct individuals and at various scales. These basic discoveries can inform realistic route-choice models that are not based on optimization, having an impact on several applications, such as infrastructure planning, routing recommendation systems and new mobility solutions. © 2016 The Author(s).

  1. Monitoring cellular behaviour using Raman spectroscopy for tissue engineering and regenerative medicine applications.

    Science.gov (United States)

    Boyd, A R; Burke, G A; Meenan, B J

    2010-08-01

    Raman spectroscopy has been used to determine the chemical composition of materials for over 70 years. Recent spectacular advances in laser and CCD camera technology creating instruments with higher sensitivity and lower cost have initiated a strong resurgence in the technique, ranging from fundamental research to process control methodology. One such area of increased potential is in tissue engineering and regenerative medicine (TERM), where autologous cell culture, stem cell biology and growth of human cells on biomaterial scaffolds are of high importance. Traditional techniques for the in vitro analysis of biochemical cell processes involves cell techniques such as fixation, lysis or the use of radioactive or chemical labels which are time consuming and can involve the perpetuation of artefacts. Several studies have already shown the potential of Raman spectroscopy to provide useful information on key biochemical markers within cells, however, many of these studies have utilised micro- or confocal Raman to do this, which are not suited to the rapid and non-invasive monitoring of cells. For this study a versatile fit-for-purpose Raman spectrometer was used, employing a macro-sampling optical platform (laser spot size 100 mum at focus on the sample) to discriminate between different TERM relevant cell types and viable and non-viable cells. The results clearly show that the technique is capable of obtaining Raman spectra from live cells in a non-destructive, rapid and non-invasive manner, however, in these experiments it was not possible to discriminate between different cell lines. Despite this, notable differences were observed in the spectra obtained from viable and non-viable cells, showing significant changes in the spectral profiles of protein, DNA/RNA and lipid cell constituents after cell death. It is evident that the method employed here shows significant potential for further utilisation in TERM, providing data directly from live cells that fits within a quality assurance framework and provides the opportunity to analyse cells in a non-destructive manner.

  2. Cellular phones: are they detrimental?

    Science.gov (United States)

    Salama, Osama E; Abou El Naga, Randa M

    2004-01-01

    The issue of possible health effects of cellular phones is very much alive in the public's mind where the rapid increase in the number of the users of cell phones in the last decade has increased the exposure of people to the electromagnetic fields (EMFs). Health consequences of long term use of mobile phones are not known in detail but available data indicates the development of non specific annoying symptoms on acute exposure to mobile phone radiations. In an attempt to determine the prevalence of such cell phones associated health manifestations and the factors affecting their occurrence, a cross sectional study was conducted in five randomly selected faculties of Alexandria University. Where, 300 individuals including teaching staff, students and literate employee were equally allocated and randomly selected among the five faculties. Data about mobile phone's users and their medical history, their pattern of mobile usage and the possible deleterious health manifestations associated with cellular phone use was collected. The results revealed 68% prevalence of mobile phone usage, nearly three quarters of them (72.5%) were complainers of the health manifestations. They suffered from headache (43%), earache (38.3%), sense of fatigue (31.6%), sleep disturbance (29.5%), concentration difficulty (28.5%) and face burning sensation (19.2%). Both univariate and multivariate analysis were consistent in their findings. Symptomatic users were found to have significantly higher frequency of calls/day, longer call duration and longer total duration of mobile phone usage/day than non symptomatic users. For headache both call duration and frequency of calls/day were the significant predicting factors for its occurrence (chi2 = 18.208, p = 0.0001). For earache, in addition to call duration, the longer period of owning the mobile phone were significant predictors (chi2 = 16.996, p = 0.0002). Sense of fatigue was significantly affected by both call duration and age of the user

  3. Trends in information behaviour research

    DEFF Research Database (Denmark)

    Greifeneder, Elke Susanne

    2014-01-01

    Introduction. This paper traces current trends in information behaviour research, both in terms of methods and topics. Results are put into relation to the previous trend analysis by Julien et al. (2011) and Vakkari (2008). Method. Trends derive from a publication analysis taken from information...... behaviour related publication venues between 2012 and 2014. Analysis. Publication titles, authors, years, publication venue, methods and topics were collected and quantitatively analysed. Results. Qualitative methods still dominate information behaviour research. Content analysis and participatory designs...... are gaining terrain. Information seeking is still the major topic of interest. Important newer topics are studies focusing on users’ context and on special needs. Conclusion. Information behaviour research has evolved a great deal over the last years and has taken on new methods and new topics. A discussion...

  4. Norms for environmentally responsible behaviour

    DEFF Research Database (Denmark)

    Thøgersen, John

    assessment of the taxonomy is carried out based of a survey of a random sample of Danish residents 18 years or older. A range of norm constructs were measured with regard to four environmentally relevant behaviours: buying organic milk, buying energy saving light bulbs, source-separating compostable kitchen...... waste, and using public transportation for work and shopping. The frequency of performing the four behaviours was measured as well. The revised taxonomy possesses content, predictive, and nomological validity and satisfactory test-retest reliability. The taxonomy's construct and discriminant validity...... is also supported, with the reservation that the different behavioural references are more than just different methods of measuring the same latent construct(s). People evidently hold different norms for different environmentally responsible behaviours....

  5. Trends in information behaviour research

    DEFF Research Database (Denmark)

    Greifeneder, Elke Susanne

    2014-01-01

    behaviour related publication venues between 2012 and 2014. Analysis. Publication titles, authors, years, publication venue, methods and topics were collected and quantitatively analysed. Results. Qualitative methods still dominate information behaviour research. Content analysis and participatory designs......Introduction. This paper traces current trends in information behaviour research, both in terms of methods and topics. Results are put into relation to the previous trend analysis by Julien et al. (2011) and Vakkari (2008). Method. Trends derive from a publication analysis taken from information...... are gaining terrain. Information seeking is still the major topic of interest. Important newer topics are studies focusing on users’ context and on special needs. Conclusion. Information behaviour research has evolved a great deal over the last years and has taken on new methods and new topics. A discussion...

  6. Customer satisfaction and complaint behaviour

    African Journals Online (AJOL)

    kirstam

    must in the eyes of the customer. This could be ... Coping refers to the psychological and behavioural efforts undertaken ... Tshwane region of Gauteng. ... been used successfully to measure consumers' expectations for and satisfaction/.

  7. Media violence and youth behaviour

    African Journals Online (AJOL)

    QuickSilver

    2003-05-07

    May 7, 2003 ... forms and includes rock music and music videos, advertising, video and computer games as well computers and the internet.(1). In addition, print ... Media exposure is known to influence knowledge, behaviour and value ...

  8. Measuring risky adolescent cycling behaviour.

    Science.gov (United States)

    Feenstra, Hans; Ruiter, Robert A C; Schepers, Jan; Peters, Gjalt-Jorn; Kok, Gerjo

    2011-09-01

    Adolescents are at a greater risk of being involved in traffic accidents than most other age groups, even before they start driving cars. This article aims to determine the factor structure of a self-report questionnaire measuring adolescent risky cycling behaviour, the ACBQ (Adolescent Cycling Behaviour Questionnaire). The questionnaire's structure was based on the widely used Driver Behaviour Questionnaire (DBQ). A sample of secondary school students (N = 1749; age range: 13-18 years) filled out the questionnaire. Factor analysis revealed a three-factor structure underlying the questionnaire, which was confirmed on two equally large portions of the entire sample. These three underlying factors were identified as errors, common violations and exceptional violations. The ACBQ is a useful instrument for measuring adolescents' risky cycling behaviour.

  9. Where is behavioural ecology going?

    Science.gov (United States)

    Owens, Ian P F

    2006-07-01

    Since the 1990s, behavioural ecologists have largely abandoned some traditional areas of interest, such as optimal foraging, but many long-standing challenges remain. Moreover, the core strengths of behavioural ecology, including the use of simple adaptive models to investigate complex biological phenomena, have now been applied to new puzzles outside behaviour. But this strategy comes at a cost. Replication across studies is rare and there have been few tests of the underlying genetic assumptions of adaptive models. Here, I attempt to identify the key outstanding questions in behavioural ecology and suggest that researchers must make greater use of model organisms and evolutionary genetics in order to make substantial progress on these topics.

  10. Characterization of fly ashes from a municipal solid waste incinerator to explore its using in construction; Caracterizacion de cenizas procedentes de plantas de incineracion de residuos solidos urbanos para su posible utilizacion en construccion

    Energy Technology Data Exchange (ETDEWEB)

    Alaejos Gutierrez, M. P.

    2002-07-01

    The paper describes the physical and chemical characterization of fly ashes from municipal solid waste incinerator. The objective is to explore potential applications of this residue in construction products. The results show the no pozzolanic nature of the fly ashes, so its utilization as mineral admixture is discarded. however, the study reveals the expansive character of the fly ashes when are mixed with water. The results of X-ray diffraction confirm the presence of metallic aluminium in the fly ash as the origin of this expansion. This chemical reaction generates a considerable amount of hydrogen, inflammable gas. Three ways to avoid this reaction are proposed. On the other way, the expansive behaviour of the fly ashes allow to explore its possible application to produce cellular mortars, as the traditional production of these mortars have several similarities with the reaction of fly ash and water. (Author) 9 refs.

  11. Intrinsic Simulations between Stochastic Cellular Automata

    Directory of Open Access Journals (Sweden)

    Pablo Arrighi

    2012-08-01

    Full Text Available The paper proposes a simple formalism for dealing with deterministic, non-deterministic and stochastic cellular automata in a unifying and composable manner. Armed with this formalism, we extend the notion of intrinsic simulation between deterministic cellular automata, to the non-deterministic and stochastic settings. We then provide explicit tools to prove or disprove the existence of such a simulation between two stochastic cellular automata, even though the intrinsic simulation relation is shown to be undecidable in dimension two and higher. The key result behind this is the caracterization of equality of stochastic global maps by the existence of a coupling between the random sources. We then prove that there is a universal non-deterministic cellular automaton, but no universal stochastic cellular automaton. Yet we provide stochastic cellular automata achieving optimal partial universality.

  12. Collective behaviour across animal species

    Science.gov (United States)

    Delellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M.; Porfiri, Maurizio

    2014-01-01

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  13. Collective behaviour across animal species.

    Science.gov (United States)

    DeLellis, Pietro; Polverino, Giovanni; Ustuner, Gozde; Abaid, Nicole; Macrì, Simone; Bollt, Erik M; Porfiri, Maurizio

    2014-01-16

    We posit a new geometric perspective to define, detect, and classify inherent patterns of collective behaviour across a variety of animal species. We show that machine learning techniques, and specifically the isometric mapping algorithm, allow the identification and interpretation of different types of collective behaviour in five social animal species. These results offer a first glimpse at the transformative potential of machine learning for ethology, similar to its impact on robotics, where it enabled robots to recognize objects and navigate the environment.

  14. Applied mechanics of solids

    CERN Document Server

    Bower, Allan F

    2009-01-01

    Modern computer simulations make stress analysis easy. As they continue to replace classical mathematical methods of analysis, these software programs require users to have a solid understanding of the fundamental principles on which they are based. Develop Intuitive Ability to Identify and Avoid Physically Meaningless Predictions Applied Mechanics of Solids is a powerful tool for understanding how to take advantage of these revolutionary computer advances in the field of solid mechanics. Beginning with a description of the physical and mathematical laws that govern deformation in solids, the text presents modern constitutive equations, as well as analytical and computational methods of stress analysis and fracture mechanics. It also addresses the nonlinear theory of deformable rods, membranes, plates, and shells, and solutions to important boundary and initial value problems in solid mechanics. The author uses the step-by-step manner of a blackboard lecture to explain problem solving methods, often providing...

  15. Autophagy and mitophagy in cellular damage control

    Directory of Open Access Journals (Sweden)

    Jianhua Zhang

    2013-01-01

    Full Text Available Autophagy and mitophagy are important cellular processes that are responsible for breaking down cellular contents, preserving energy and safeguarding against accumulation of damaged and aggregated biomolecules. This graphic review gives a broad summary of autophagy and discusses examples where autophagy is important in controlling protein degradation. In addition we highlight how autophagy and mitophagy are involved in the cellular responses to reactive species and mitochondrial dysfunction. The key signaling pathways for mitophagy are described in the context of bioenergetic dysfunction.

  16. Cellular Mechanisms of Transcranial Direct Current Stimulation

    Science.gov (United States)

    2016-07-14

    effects of any number of cellular processes , where the endogenous state is such that it can only be modulated in one direction. Conclusions and...activated synaptic processes and provided a cellular substrate for these changes. This proposal therefore provided a detailed cellular-level...which are involved in synaptic processing , might additionally contribute to the effects of DCS (Purpura and McMurtry, 1965a, b; Bikson et al., 2004

  17. THE RELATIONSHIPS OF THREE ELEMENTARY CELLULAR AUTOMATA

    Institute of Scientific and Technical Information of China (English)

    Zhisong JIANG

    2006-01-01

    Limit language complexity of cellular automata which is first posed by S. Wolfram has become a new branch of cellular automata. In this paper, we obtain two interesting relationships between elementary cellular automata of rules 126, 146(182) and 18, and prove that if the limit language of rule 18 is not regular, nor are the limit languages of rules 126 and 146(182).

  18. Rheology evolution of sludge through high-solid anaerobic digestion.

    Science.gov (United States)

    Dai, Xiaohu; Gai, Xin; Dong, Bin

    2014-12-01

    The main purpose of this study was to investigate the rheology evolution of sludge through high-solid anaerobic digestion (AD) and its dependency on sludge retention time (SRT) and temperature of AD reactor. The operation performance of high-solid AD reactors were also studied. The results showed that sludge became much more flowable after high-solid AD. It was found that the sludge from reactors with long SRT exhibited low levels of shear stress, viscosity, yield stress, consistency index, and high value of flow behaviour index. While the flowability of sludge from thermophilic AD reactors were better than that of sludge from mesophilic AD reactors though the solid content of the formers were higher than that of the latters, which could be attributed to the fact that the formers had more amount of free and interstitial moisture. It might be feasible to use sludge rheology as an AD process controlling parameter. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Efficiency of cellular information processing

    CERN Document Server

    Barato, Andre C; Seifert, Udo

    2014-01-01

    We show that a rate of conditional Shannon entropy reduction, characterizing the learning of an internal process about an external process, is bounded by the thermodynamic entropy production. This approach allows for the definition of an informational efficiency that can be used to study cellular information processing. We analyze three models of increasing complexity inspired by the E. coli sensory network, where the external process is an external ligand concentration jumping between two values. We start with a simple model for which ATP must be consumed so that a protein inside the cell can learn about the external concentration. With a second model for a single receptor we show that the rate at which the receptor learns about the external environment can be nonzero even without any dissipation inside the cell since chemical work done by the external process compensates for this learning rate. The third model is more complete, also containing adaptation. For this model we show inter alia that a bacterium i...

  20. The origins of cellular life.

    Science.gov (United States)

    Schrum, Jason P; Zhu, Ting F; Szostak, Jack W

    2010-09-01

    Understanding the origin of cellular life on Earth requires the discovery of plausible pathways for the transition from complex prebiotic chemistry to simple biology, defined as the emergence of chemical assemblies capable of Darwinian evolution. We have proposed that a simple primitive cell, or protocell, would consist of two key components: a protocell membrane that defines a spatially localized compartment, and an informational polymer that allows for the replication and inheritance of functional information. Recent studies of vesicles composed of fatty-acid membranes have shed considerable light on pathways for protocell growth and division, as well as means by which protocells could take up nutrients from their environment. Additional work with genetic polymers has provided insight into the potential for chemical genome replication and compatibility with membrane encapsulation. The integration of a dynamic fatty-acid compartment with robust, generalized genetic polymer replication would yield a laboratory model of a protocell with the potential for classical Darwinian biological evolution, and may help to evaluate potential pathways for the emergence of life on the early Earth. Here we discuss efforts to devise such an integrated protocell model.

  1. Cellular Senescence: A Translational Perspective

    Directory of Open Access Journals (Sweden)

    James L. Kirkland

    2017-07-01

    Full Text Available Cellular senescence entails essentially irreversible replicative arrest, apoptosis resistance, and frequently acquisition of a pro-inflammatory, tissue-destructive senescence-associated secretory phenotype (SASP. Senescent cells accumulate in various tissues with aging and at sites of pathogenesis in many chronic diseases and conditions. The SASP can contribute to senescence-related inflammation, metabolic dysregulation, stem cell dysfunction, aging phenotypes, chronic diseases, geriatric syndromes, and loss of resilience. Delaying senescent cell accumulation or reducing senescent cell burden is associated with delay, prevention, or alleviation of multiple senescence-associated conditions. We used a hypothesis-driven approach to discover pro-survival Senescent Cell Anti-apoptotic Pathways (SCAPs and, based on these SCAPs, the first senolytic agents, drugs that cause senescent cells to become susceptible to their own pro-apoptotic microenvironment. Several senolytic agents, which appear to alleviate multiple senescence-related phenotypes in pre-clinical models, are beginning the process of being translated into clinical interventions that could be transformative.

  2. The cellular toxicity of aluminium.

    Science.gov (United States)

    Exley, C; Birchall, J D

    1992-11-07

    Aluminium is a serious environmental toxicant and is inimical to biota. Omnipresent, it is linked with a number of disorders in man including Alzheimer's disease, Parkinson's dementia and osteomalacia. Evidence supporting aluminium as an aetiological agent in such disorders is not conclusive and suffers principally from a lack of consensus with respect to aluminium's toxic mode of action. Obligatory to the elucidation of toxic mechanisms is an understanding of the biological availability of aluminium. This describes the fate of and response to aluminium in any biological system and is thus an important influence of the toxicity of aluminium. A general theme in much aluminium toxicity is an accelerated cell death. Herein mechanisms are described to account for cell death from both acute and chronic aluminium challenges. Aluminium associations with both extracellular surfaces and intracellular ligands are implicated. The cellular response to aluminium is found to be biphasic having both stimulatory and inhibitory components. In either case the disruption of second messenger systems is observed and GTPase cycles are potential target sites. Specific ligands for aluminium at these sites are unknown though are likely to be proteins upon which oxygen-based functional groups are orientated to give exceptionally strong binding with the free aluminium ion.

  3. IMPACT OF SPATIAL FILTER ON LAND-USE CHANGES MODELLING USING URBAN CELLULAR AUTOMATA

    Directory of Open Access Journals (Sweden)

    M. Omidipoor

    2017-09-01

    Full Text Available Urban cellular automata is used vastly in simulating of urban evolutions and dynamics. Finding an appropriate neighbourhood size in urban cellular automata modelling is important because the outputs are strongly influenced by input parameters. This paper investigates the impact of spatial filters on behaviour and outcome of urban cellular automata models. In this study different spatial filters in various sizes including 3*3, 5*5, 7*7, 9*9, 11*11, 13*13, 15*15 and 17*17 cells are used in a scenario of land-use changes. The proposed method is examined changes in size and shape of spatial filter whereas the resolution was kept fixed. The implementation results in Ahvaz city demonstrated that KAPPA index is changed in different shapes and types at the time when different spatial filters are used. However, circular shape with size of 5*5 offers better accuracy.

  4. Optimized Cellular Core for Rotorcraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Patz Materials and Technologies proposes to develop a unique structural cellular core material to improve mechanical performance, reduce platform weight and lower...

  5. Integration of mobile satellite and cellular systems

    Science.gov (United States)

    Drucker, Elliott H.; Estabrook, Polly; Pinck, Deborah; Ekroot, Laura

    1993-01-01

    By integrating the ground based infrastructure component of a mobile satellite system with the infrastructure systems of terrestrial 800 MHz cellular service providers, a seamless network of universal coverage can be established. Users equipped for both cellular and satellite service can take advantage of a number of features made possible by such integration, including seamless handoff and universal roaming. To provide maximum benefit at lowest posible cost, the means by which these systems are integrated must be carefully considered. Mobile satellite hub stations must be configured to efficiently interface with cellular Mobile Telephone Switching Offices (MTSO's), and cost effective mobile units that provide both cellular and satellite capability must be developed.

  6. Influence of IMC in the Semisolid Behaviour of an Eutectic Sn-Pb/Cu Slurry

    Science.gov (United States)

    Merizalde, Carlos; Cabrera, José-María; Prado, José-Manuel

    2007-04-01

    A mixture of a liquid Sn-Pb alloy reinforced with solid Cu particles has been found to show thixotropic and pseudoplastic behaviour. The presence of an intermetallic compound (IMC) between the Cu particles and the molten matrix has some very important consequences in the rheological behaviour of the slurry. The semisolid material is obtained mixing a sufficient amount of Cu particles with a liquid eutectic Sn-Pb alloy by mechanical stirring at a given temperature and time. The intermetallic compound is formed from the reaction of solid Cu and liquid Sn. This reaction results in some displacement in the phase diagram, affecting the liquid alloy composition, moving the liquidus temperature and therefore altering the balance of %wt solid- %wt liquid necessary to obtain the best thixotropic behaviour. In this work a model of the solid fraction of the slurry taking into account the IMC growth rate is presented. This model is also used to predict the processing window under which the material keeps the thixotropic behaviour.

  7. Alkalizing Reactions Streamline Cellular Metabolism in Acidogenic Microorganisms

    Science.gov (United States)

    Arioli, Stefania; Ragg, Enzio; Scaglioni, Leonardo; Fessas, Dimitrios; Signorelli, Marco; Karp, Matti; Daffonchio, Daniele; De Noni, Ivano; Mulas, Laura; Oggioni, Marco; Guglielmetti, Simone; Mora, Diego

    2010-01-01

    An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms. PMID:21152088

  8. Daily magnesium fluxes regulate cellular timekeeping and energy balance.

    Science.gov (United States)

    Feeney, Kevin A; Hansen, Louise L; Putker, Marrit; Olivares-Yañez, Consuelo; Day, Jason; Eades, Lorna J; Larrondo, Luis F; Hoyle, Nathaniel P; O'Neill, John S; van Ooijen, Gerben

    2016-04-21

    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behaviour and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes. A fundamental knowledge gap exists, however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg(2+)]i, which act as a cell-autonomous timekeeping component to determine key clock properties both in a human cell line and in a unicellular alga that diverged from each other more than 1 billion years ago. Given the essential role of Mg(2+) as a cofactor for ATP, a functional consequence of [Mg(2+)]i oscillations is dynamic regulation of cellular energy expenditure over the daily cycle. Mechanistically, we find that these rhythms provide bilateral feedback linking rhythmic metabolism to clock-controlled gene expression. The global regulation of nucleotide triphosphate turnover by intracellular Mg(2+) availability has potential to impact upon many of the cell's more than 600 MgATP-dependent enzymes and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR is regulated through [Mg(2+)]i oscillations. It will now be important to identify which additional biological processes are subject to this form of regulation in tissues of multicellular organisms such as plants and humans, in the context of health and disease.

  9. Alkalizing reactions streamline cellular metabolism in acidogenic microorganisms.

    Directory of Open Access Journals (Sweden)

    Stefania Arioli

    Full Text Available An understanding of the integrated relationships among the principal cellular functions that govern the bioenergetic reactions of an organism is necessary to determine how cells remain viable and optimise their fitness in the environment. Urease is a complex enzyme that catalyzes the hydrolysis of urea to ammonia and carbonic acid. While the induction of urease activity by several microorganisms has been predominantly considered a stress-response that is initiated to generate a nitrogen source in response to a low environmental pH, here we demonstrate a new role of urease in the optimisation of cellular bioenergetics. We show that urea hydrolysis increases the catabolic efficiency of Streptococcus thermophilus, a lactic acid bacterium that is widely used in the industrial manufacture of dairy products. By modulating the intracellular pH and thereby increasing the activity of β-galactosidase, glycolytic enzymes and lactate dehydrogenase, urease increases the overall change in enthalpy generated by the bioenergetic reactions. A cooperative altruistic behaviour of urease-positive microorganisms on the urease-negative microorganisms within the same environment was also observed. The physiological role of a single enzymatic activity demonstrates a novel and unexpected view of the non-transcriptional regulatory mechanisms that govern the bioenergetics of a bacterial cell, highlighting a new role for cytosol-alkalizing biochemical pathways in acidogenic microorganisms.

  10. Philanthropic behaviour and motives

    Directory of Open Access Journals (Sweden)

    Vladimír Hyánek

    2013-01-01

    Full Text Available Even though philanthropy tends to be considered a sociological theme rather than an economic one, it poses a number of questions that challenge economists as well. We chose to address the following: How can economists contribute to the theories related to philanthropy? We examine some terms that are used in public economics theory and use them to explore the issues of philanthropy like Samaritan’s Dilemma, the Prisoner’s Dilemma, and the Free-Rider Problem, which we consider to be interesting and inspiring (Stone, 2008. We have to find and identify the social values of donors and volunteers rather than their economic values, because economists are not fully able to explain empathy, altruism, and helpful behaviour using traditional economic principles (Rutherford, 2008. The theoretical frame is supported by relevant empirical data. Before starting a large-scale survey, we decided to conduct smaller pre-research probes into people’s attitudes towards altruism, philanthropy, and giving. Even though our sample was not fully representative, the responses that we collected generated interesting findings about people’s views and attitudes. The first wave of data was collected between February and April 2009; the second wave between February and April 2010.Because of this pilot research mission and because of the budget restriction too, the non-representative sample of 823 respondents has been used; students of our Public Economics study programme were used as interviewers. They have also obtained a proper training of the professional sociologist. Students utilized the face to face interviewing method; non-standardized questions were immediately recorded into the reply form. Questions were divided into three groups with typical characteristics. The first one focuses on personal (individual motives for financial donating (only financial gifts for non-profit organizations. Second part examines the attitudes of individual towards the non

  11. Moderators of the intention-behaviour and perceived behavioural control-behaviour relationships for leisure-time physical activity

    OpenAIRE

    Godin Gaston; Amireault Steve; Vohl Marie-Claude; Pérusse Louis

    2008-01-01

    Abstract Background Intention is a key determinant of action. However, there is a gap between intention and behavioural performance that remains to be explained. Therefore, the aim of this study was to identify moderators of the intention-behaviour and perceived behavioural control (PBC)- behaviour relationships for leisure-time physical activity. Method This was tested in reference to Ajzen's Theory of Planned Behaviour. A sample of 300 volunteers, 192 women and 108 men, aged 18 to 55, parti...

  12. Psychological aspects of road user behaviour

    NARCIS (Netherlands)

    Rothengatter, J.A.

    1997-01-01

    The behaviour of road users is an important factor in accident causation. Traffic psychology, defined as ''the study of the behaviour of road users and the psychological processes underlying that behaviour'', attempts to identify the determinants of road user behaviour with the aim of developing eff

  13. Agent-based simulation of animal behaviour

    NARCIS (Netherlands)

    C.M. Jonker (Catholijn); J. Treur

    1998-01-01

    textabstract In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for

  14. Psychological aspects of road user behaviour

    NARCIS (Netherlands)

    Rothengatter, J.A.

    The behaviour of road users is an important factor in accident causation. Traffic psychology, defined as ''the study of the behaviour of road users and the psychological processes underlying that behaviour'', attempts to identify the determinants of road user behaviour with the aim of developing

  15. Erosion behaviour of epoxy based unidirectionl (GFRP composite materials

    Directory of Open Access Journals (Sweden)

    Y. Fouad

    2011-03-01

    Full Text Available In the present work, the solid particle erosion behaviour and wear mechanism of commercial epoxy based unidirectional glass fibre reinforced plastics (GFRP composites were investigated. The erosion experiments have been carried out using irregular silica sand (SiC particles (150 ± 15 μm as an erodent. The erosion losses of these composites were evaluated at various impingement angles (30°, 60° and 90° with the change of both of erosion time and pressure. The erosion behaviour of (GFRP has changed from ductile to brittle at 60° impingement angle and the erosion loss was the highest. The morphology of eroded surfaces was observed under scanning electron microscope and damage mechanisms were discussed.

  16. Pulsed feedback defers cellular differentiation.

    Directory of Open Access Journals (Sweden)

    Joe H Levine

    2012-01-01

    Full Text Available Environmental signals induce diverse cellular differentiation programs. In certain systems, cells defer differentiation for extended time periods after the signal appears, proliferating through multiple rounds of cell division before committing to a new fate. How can cells set a deferral time much longer than the cell cycle? Here we study Bacillus subtilis cells that respond to sudden nutrient limitation with multiple rounds of growth and division before differentiating into spores. A well-characterized genetic circuit controls the concentration and phosphorylation of the master regulator Spo0A, which rises to a critical concentration to initiate sporulation. However, it remains unclear how this circuit enables cells to defer sporulation for multiple cell cycles. Using quantitative time-lapse fluorescence microscopy of Spo0A dynamics in individual cells, we observed pulses of Spo0A phosphorylation at a characteristic cell cycle phase. Pulse amplitudes grew systematically and cell-autonomously over multiple cell cycles leading up to sporulation. This pulse growth required a key positive feedback loop involving the sporulation kinases, without which the deferral of sporulation became ultrasensitive to kinase expression. Thus, deferral is controlled by a pulsed positive feedback loop in which kinase expression is activated by pulses of Spo0A phosphorylation. This pulsed positive feedback architecture provides a more robust mechanism for setting deferral times than constitutive kinase expression. Finally, using mathematical modeling, we show how pulsing and time delays together enable "polyphasic" positive feedback, in which different parts of a feedback loop are active at different times. Polyphasic feedback can enable more accurate tuning of long deferral times. Together, these results suggest that Bacillus subtilis uses a pulsed positive feedback loop to implement a "timer" that operates over timescales much longer than a cell cycle.

  17. Multifunctional solid/solid phononic crystal

    Science.gov (United States)

    Swinteck, N.; Vasseur, J. O.; Hladky-Hennion, A. C.; Croënne, C.; Bringuier, S.; Deymier, P. A.

    2012-07-01

    A two-dimensional, solid/solid phononic crystal (PC) comprised a square array of steel cylinders in epoxy is shown to perform a variety of spectral, wave vector, and phase-space functions. Over a range of operating frequencies, the PC's elastic band structure shows uniquely shaped equifrequency contours that are only accessible to excitations of longitudinal polarization. Under this condition, the PC is shown to behave as (1) an acoustic wave collimator, (2) a defect-less wave guide, (3) a directional source for elastic waves, (4) an acoustic beam splitter, (5) a phase-control device, and (6) a k-space multiplexer. Wave vector diagrams and finite-difference time-domain simulations are employed to authenticate the above mentioned capabilities.

  18. Low-Dimensional Solids

    CERN Document Server

    Bruce, Duncan W; O'Hare, Dermot

    2010-01-01

    With physical properties that often may not be described by the transposition of physical laws from 3D space across to 2D or even 1D space, low-dimensional solids exhibit a high degree of anisotropy in the spatial distribution of their chemical bonds. This means that they can demonstrate new phenomena such as charge-density waves and can display nanoparticulate (0D), fibrous (1D) and lamellar (2D) morphologies. Low-Dimensional Solids presents some of the most recent research into the synthesis and properties of these solids and covers: Metal Oxide Nanoparticles; Inorganic Nanotubes and Nanowir

  19. Applications in solid mechanics

    DEFF Research Database (Denmark)

    Ølgaard, Kristian Breum; Wells, Garth N.

    2012-01-01

    Problems in solid mechanics constitute perhaps the largest field of application of finite element methods. The vast majority of solid mechanics problems involve the standard momentum balance equation, posed in a Lagrangian setting, with different models distinguished by the choice of nonlinear...... or linearized kinematics, and the constitutive model for determining the stress. For some common models, the constitutive relationships are rather complex. This chapter addresses a number of canonical solid mechanics models in the context of automated modeling, and focuses on some pertinent issues that arise...

  20. Solid propellant motor

    Science.gov (United States)

    Shafer, J. I.; Marsh, H. E., Jr. (Inventor)

    1978-01-01

    A case bonded end burning solid propellant rocket motor is described. A propellant with sufficiently low modulus to avoid chamber buckling on cooling from cure and sufficiently high elongation to sustain the stresses induced without cracking is used. The propellant is zone cured within the motor case at high pressures equal to or approaching the pressure at which the motor will operate during combustion. A solid propellant motor with a burning time long enough that its spacecraft would be limited to a maximum acceleration of less than 1 g is provided by one version of the case bonded end burning solid propellant motor of the invention.

  1. The solid state maser

    CERN Document Server

    Orton, J W; Walling, J C; Ter Haar, D

    1970-01-01

    The Solid State Maser presents readings related to solid state maser amplifier from the first tentative theoretical proposals that appeared in the early 1950s to the successful realization of practical devices and their application to satellite communications and radio astronomy almost exactly 10 years later. The book discusses a historical account of the early developments (including that of the ammonia maser) of solid state maser; the properties of paramagnetic ions in crystals; the development of practical low noise amplifiers; and the characteristics of maser devices designed for communica

  2. Laser cooling of solids

    OpenAIRE

    Nemova, Galina

    2009-01-01

    Parallel to advances in laser cooling of atoms and ions in dilute gas phase, which has progressed immensely, resulting in physics Nobel prizes in 1997 and 2001, major progress has recently been made in laser cooling of solids. I compare the physical nature of the laser cooling of atoms and ions with that of the laser cooling of solids. I point out all advantages of this new and very promising area of laser physics. Laser cooling of solids (optical refrigeration) at the present time can be lar...

  3. Best behaviour? Ontologies and the formal description of animal behaviour

    KAUST Repository

    Gkoutos, Georgios V.

    2015-07-28

    The development of ontologies for describing animal behaviour has proved to be one of the most difficult of all scientific knowledge domains. Ranging from neurological processes to human emotions, the range and scope needed for such ontologies is highly challenging, but if data integration and computational tools such as automated reasoning are to be fully applied in this important area the underlying principles of these ontologies need to be better established and development needs detailed coordination. Whilst the state of scientific knowledge is always paramount in ontology and formal description framework design, this is a particular problem with neurobehavioural ontologies where our understanding of the relationship between behaviour and its underlying biophysical basis is currently in its infancy. In this commentary, we discuss some of the fundamental problems in designing and using behaviour ontologies, and present some of the best developed tools in this domain. © 2015 Springer Science+Business Media New York

  4. Linking behavioural syndromes and cognition: a behavioural ecology perspective.

    Science.gov (United States)

    Sih, Andrew; Del Giudice, Marco

    2012-10-01

    With the exception of a few model species, individual differences in cognition remain relatively unstudied in non-human animals. One intriguing possibility is that variation in cognition is functionally related to variation in personality. Here, we review some examples and present hypotheses on relationships between personality (or behavioural syndromes) and individual differences in cognitive style. Our hypotheses are based largely on a connection between fast-slow behavioural types (BTs; e.g. boldness, aggressiveness, exploration tendency) and cognitive speed-accuracy trade-offs. We also discuss connections between BTs, cognition and ecologically important aspects of decision-making, including sampling, impulsivity, risk sensitivity and choosiness. Finally, we introduce the notion of cognition syndromes, and apply ideas from theories on adaptive behavioural syndromes to generate predictions on cognition syndromes.

  5. Best behaviour? Ontologies and the formal description of animal behaviour.

    Science.gov (United States)

    Gkoutos, Georgios V; Hoehndorf, Robert; Tsaprouni, Loukia; Schofield, Paul N

    2015-10-01

    The development of ontologies for describing animal behaviour has proved to be one of the most difficult of all scientific knowledge domains. Ranging from neurological processes to human emotions, the range and scope needed for such ontologies is highly challenging, but if data integration and computational tools such as automated reasoning are to be fully applied in this important area the underlying principles of these ontologies need to be better established and development needs detailed coordination. Whilst the state of scientific knowledge is always paramount in ontology and formal description framework design, this is a particular problem with neurobehavioural ontologies where our understanding of the relationship between behaviour and its underlying biophysical basis is currently in its infancy. In this commentary, we discuss some of the fundamental problems in designing and using behaviour ontologies, and present some of the best developed tools in this domain.

  6. Immune cellular response to HPV: current concepts

    Directory of Open Access Journals (Sweden)

    Maria Alice Guimarães Gonçalves

    Full Text Available Although cellular immunity is essential for the elimination of human papillomavirus (HPV, the mechanisms involved are still poorly understood. We summarize the main mechanisms involved in cellular immune response to infections caused by HPV. Immunotherapies for HPV-related cancers require the disruption of T-cell response control mechanisms, associated with the stimulation of the Th1 cytokine response.

  7. LMS filters for cellular CDMA overlay

    OpenAIRE

    1996-01-01

    This paper extends and complements previous research we have performed on the performance of nonadaptive narrowband suppression filters when used in cellular CDMA overlay situations. In this paper, an adaptive LMS filter is applied to cellular CDMA overlay situations in order to reject narrowband interference.

  8. From Cnn Dynamics to Cellular Wave Computers

    Science.gov (United States)

    Roska, Tamas

    2013-01-01

    Embedded in a historical overview, the development of the Cellular Wave Computing paradigm is presented, starting from the standard CNN dynamics. The theoretical aspects, the physical implementation, the innovation process, as well as the biological relevance are discussed in details. Finally, the latest developments, the physical versus virtual cellular machines, as well as some open questions are presented.

  9. Recent development of cellular manufacturing systems

    Indian Academy of Sciences (India)

    P K Arora; A Haleem; M K Singh

    2013-06-01

    Cellular manufacturing system has been proved a vital approach for batch and job shop production systems. Group technology has been an essential tool for developing a cellular manufacturing system. The paper aims to discuss various cell formation techniques and highlights the significant research work done in past over the years and attempts to points out the gap in research.

  10. Cellular encoding for interactive evolutionary robotics

    NARCIS (Netherlands)

    Gruau, F.C.; Quatramaran, K.

    1996-01-01

    This work reports experiments in interactive evolutionary robotics. The goal is to evolve an Artificial Neural Network (ANN) to control the locomotion of an 8-legged robot. The ANNs are encoded using a cellular developmental process called cellular encoding. In a previous work similar experiments ha

  11. The missing link between values and behaviour

    DEFF Research Database (Denmark)

    Brunsø, Karen

    For a long time human values have been perceived as abstrat cognitions representing desired goals or end-states which motivate humnan behaviour. A number of studies have tried to explore the link between values and behaviour, but often different constructs are included as intermediate links betwe...... and lifestyle and behaviour. Based on this appraoch we collected data covering values, lifestyle and behaviour, and estimated the cogntiive hierarchy from values to lifestyle to behaviour by structural equation models....

  12. Agent-based simulation of animal behaviour

    OpenAIRE

    Jonker, C.M.; Treur, J.

    1998-01-01

    In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for multi-agent systems DESIRE and its software environment supports the conceptual and detailed design, and execution of these models. Experiments reported in the literature on animal behaviour have been simulated for a num...

  13. The yielding transition in amorphous solids under oscillatory shear deformation

    Science.gov (United States)

    Leishangthem, Premkumar; Parmar, Anshul D. S.; Sastry, Srikanth

    2017-01-01

    Amorphous solids are ubiquitous among natural and man-made materials. Often used as structural materials for their attractive mechanical properties, their utility depends critically on their response to applied stresses. Processes underlying such mechanical response, and in particular the yielding behaviour of amorphous solids, are not satisfactorily understood. Although studied extensively, observed yielding behaviour can be gradual and depend significantly on conditions of study, making it difficult to convincingly validate existing theoretical descriptions of a sharp yielding transition. Here we employ oscillatory deformation as a reliable probe of the yielding transition. Through extensive computer simulations for a wide range of system sizes, we demonstrate that cyclically deformed model glasses exhibit a sharply defined yielding transition with characteristics that are independent of preparation history. In contrast to prevailing expectations, the statistics of avalanches reveals no signature of the impending transition, but exhibit dramatic, qualitative, changes in character across the transition. PMID:28248289

  14. The mammary cellular hierarchy and breast cancer.

    Science.gov (United States)

    Oakes, Samantha R; Gallego-Ortega, David; Ormandy, Christopher J

    2014-11-01

    Advances in the study of hematopoietic cell maturation have paved the way to a deeper understanding the stem and progenitor cellular hierarchy in the mammary gland. The mammary epithelium, unlike the hematopoietic cellular hierarchy, sits in a complex niche where communication between epithelial cells and signals from the systemic hormonal milieu, as well as from extra-cellular matrix, influence cell fate decisions and contribute to tissue homeostasis. We review the discovery, definition and regulation of the mammary cellular hierarchy and we describe the development of the concepts that have guided our investigations. We outline recent advances in in vivo lineage tracing that is now challenging many of our assumptions regarding the behavior of mammary stem cells, and we show how understanding these cellular lineages has altered our view of breast cancer.

  15. Interworking of wireless lans and cellular networks

    CERN Document Server

    Song, Wei

    2014-01-01

    The next-generation of wireless communications are envisioned to be supported by heterogeneous networks by using various wireless access technologies. The popular cellular networks and wireless local area networks (WLANs) present perfectly complementary characteristics in terms of service capacity, mobility support, and quality-of-service (QoS) provisioning. The cellular/WLAN interworking is an effective way to promote the evolution of wireless networks. Interworking of Wireless LANs and Cellular Networks focuses on three aspects, namely access selection, call admission control and load sharing to investigate heterogeneous interworking for cellular/WLAN integrated networks. It not only reveals important observations but also offers useful tools for performance evaluation. The unique traffic and network characteristics are exploited to enhance interworking effectiveness. Theoretical analysis and simulation validation demonstrate benefits of cellular/WLAN interworking in real networks. Last but not the least,...

  16. The Universe as a Cellular System

    CERN Document Server

    Aragón-Calvo, Miguel A

    2014-01-01

    Cellular systems are observed everywhere in nature, from crystal domains in metals, soap froth and cucumber cells to the network of cosmological voids. Surprisingly, despite their disparate scale and origin all cellular systems follow certain scaling laws relating their geometry, topology and dynamics. Using a cosmological N-body simulation we found that the Cosmic Web, the largest known cellular system, follows the same scaling relations seen elsewhere in nature. Our results extend the validity of scaling relations in cellular systems by over 30 orders of magnitude in scale with respect to previous studies. The dynamics of cellular systems can be used to interpret local observations such as the local velocity anomaly as the result of a collapsing void in our cosmic backyard. Moreover, scaling relations depend on the curvature of space, providing an independent measure of geometry.

  17. Modeling of droplet dynamic and thermal behaviour during spray deposition

    Indian Academy of Sciences (India)

    N S Mahesh; Johnson Mendonca; M K Muralidhara; B K Muralidhara; C Ramachandra

    2003-04-01

    Mathematical modeling of supersonic gas atomization for spray forming has been investigated. Influence of the droplet dynamic and thermal behaviour on the resultant microstructure has been studied. Analytical models have been constructed taking into account the higher Reynolds number owing to supersonic gas flow. The impact velocity profiles of the droplets lend credence to the evolution of equiaxed grain morphology through dendrite fragmentation. The thermal history profile along with the fraction solid plot could yield optimized standoff distance to obtain a mushy droplet. A comparison of secondary dendrite arm spacing obtained from the mathematical model showed good agreement with experimental observations.

  18. Diffusion and wave behaviour in linear Voigt model

    CERN Document Server

    De Angelis, Monica

    2012-01-01

    A boundary value problem related to a third- order parabolic equation with a small parameter is analized. This equation models the one-dimensional evolution of many dissipative media as viscoelastic fluids or solids, viscous gases, superconducting materials, incompressible and electrically conducting fluids. Moreover, the third-order parabolic operator regularizes various non linear second order wave equations. In this paper, the hyperbolic and parabolic behaviour of the solution is estimated by means of slow time and fast time. As consequence, a rigorous asymptotic approximation for the solution is established.

  19. Solid Waste Treatment Technology

    Science.gov (United States)

    Hershaft, Alex

    1972-01-01

    Advances in research and commercial solid waste handling are offering many more processing choices. This survey discusses techniques of storage and removal, fragmentation and sorting, bulk reduction, conversion, reclamation, mining and mineral processing, and disposal. (BL)

  20. Solids Accumulation Scouting Studies

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  1. Solid Earth: Introduction

    Science.gov (United States)

    Rummel, R.

    1991-10-01

    The principles of the solid Earth program are introduced. When considering the study of solid Earth from space, satellites are used as beacons, inertial references, free fall probes and carrying platforms. The phenomenon measured by these satellites and the processes which can be studied as a result of these measurements are tabulated. The NASA solid Earth program focusses on research into surface kinematics, Earth rotation, land, ice, and ocean monitoring. The ESA solid Earth program identifies as its priority the Aristoteles mission for determining the gravity and magnetic field globally, with high spatial resolution and high accuracy. The Aristoteles mission characteristics and goals are listed. The benefits of the improved gravity information that will be provided by this mission are highlighted. This information will help in the following research: geodesy, orbit mechanics, geodynamics, oceanography, climate sea level, and the atmosphere.

  2. Solid Waste Management Districts

    Data.gov (United States)

    Vermont Center for Geographic Information — The Solid waste management districts layer is part of a dataset that contains administrative boundaries for Vermont's Agency of Natural Resources. This dataset...

  3. Gases, liquids and solids

    CERN Document Server

    Tabor, David

    1969-01-01

    It has been tradional to treat gases, liquids and solids as if they were completely unrelated material. However, this book shows that many of their bulk properties can been explained in terms of intermolecular forces.

  4. The physical behaviour of gabbroic crystal mush

    Science.gov (United States)

    Humphreys, M.; Namur, O.; Holness, M. B.

    2012-12-01

    Crystal mushes form at the boundary layers of all magma bodies, from lava flows to volcanic conduits to batholiths. The physical behaviour of a crystal mush is important in controlling a number of physical processes, from the origin of crystal-poor rhyolites, and the migration and ascent of granitic magmas, to compaction and differentiation processes in large mafic bodies. As well as strain-rate, the grain-scale microstructure of the mush is an important factor in controlling its physical behaviour, with porosity (amount of residual liquid) being particularly important. One might therefore expect to see a range of different behaviours during the crystallisation of a magma body, depending on the porosity and strain rate at any given point in the crystallisation history. We describe evidence for three different mechanical regimes affecting a gabbroic crystal mush at different scales and residual liquid contents. We focus on the Marginal Border Series of the Skaergaard Intrusion, east Greenland, which crystallised on the steeply dipping sidewalls of the intrusion. It has the advantage that, unlike in most mushes that developed on the chamber floor, thermal gradients and the effects of gravity act in orthogonal directions, allowing shear-related features to be identified and distinguished from thermal effects. The largest-scale effects are evident at the contact between the Marginal Border Series (MBS) and the Layered Series, which crystallised on the floor of the intrusion. The contact is characterised by slumping and faulting of semi-consolidated crystal mush, resulting in slippage and rotation of large packets of relatively coherent igneous 'sediment' down-slope. This process may be analogous to the formation of slumps or rotational landslides in sedimentary systems. At a smaller scale, gravitational instability of the sidewalls caused localised sagging of the crystal mush and resulted in small ductile cracks or tears that filled with interstitial liquid. Finally

  5. Moderators of the intention-behaviour and perceived behavioural control-behaviour relationships for leisure-time physical activity

    Directory of Open Access Journals (Sweden)

    Godin Gaston

    2008-02-01

    Full Text Available Abstract Background Intention is a key determinant of action. However, there is a gap between intention and behavioural performance that remains to be explained. Therefore, the aim of this study was to identify moderators of the intention-behaviour and perceived behavioural control (PBC- behaviour relationships for leisure-time physical activity. Method This was tested in reference to Ajzen's Theory of Planned Behaviour. A sample of 300 volunteers, 192 women and 108 men, aged 18 to 55, participated in the study. At baseline, the participants completed a self-administrated psychosocial questionnaire assessing Ajzen's theory variables (i.e., intention and perceived behavioural control. The behavioural measure was obtained by mail three months later. Results Multiple hierarchical regression analyses indicated that age and annual income moderated the intention-behaviour and PBC-behaviour relationships. However, in the final model predicting behaviour (R2 = .46, only the interaction term of PBC by annual income (β = .24, p = 0.0003 significantly contributed to the prediction of behaviour along with intention (β = .49, p = 0.0009 and past behaviour (β = .44, p Conclusion Physical activity promotion programs would benefit not only from focusing on increasing the intention of low intenders, but also from targeting factors that moderate the perceived behavioural control-behaviour relationships.

  6. Moderators of the intention-behaviour and perceived behavioural control-behaviour relationships for leisure-time physical activity

    Science.gov (United States)

    Amireault, Steve; Godin, Gaston; Vohl, Marie-Claude; Pérusse, Louis

    2008-01-01

    Background Intention is a key determinant of action. However, there is a gap between intention and behavioural performance that remains to be explained. Therefore, the aim of this study was to identify moderators of the intention-behaviour and perceived behavioural control (PBC)- behaviour relationships for leisure-time physical activity. Method This was tested in reference to Ajzen's Theory of Planned Behaviour. A sample of 300 volunteers, 192 women and 108 men, aged 18 to 55, participated in the study. At baseline, the participants completed a self-administrated psychosocial questionnaire assessing Ajzen's theory variables (i.e., intention and perceived behavioural control). The behavioural measure was obtained by mail three months later. Results Multiple hierarchical regression analyses indicated that age and annual income moderated the intention-behaviour and PBC-behaviour relationships. However, in the final model predicting behaviour (R2 = .46), only the interaction term of PBC by annual income (β = .24, p = 0.0003) significantly contributed to the prediction of behaviour along with intention (β = .49, p = 0.0009) and past behaviour (β = .44, p < 0.0001). Conclusion Physical activity promotion programs would benefit not only from focusing on increasing the intention of low intenders, but also from targeting factors that moderate the perceived behavioural control-behaviour relationships. PMID:18241339

  7. Solid model design simplification

    Energy Technology Data Exchange (ETDEWEB)

    Ames, A.L.; Rivera, J.J.; Webb, A.J.; Hensinger, D.M.

    1997-12-01

    This paper documents an investigation of approaches to improving the quality of Pro/Engineer-created solid model data for use by downstream applications. The investigation identified a number of sources of problems caused by deficiencies in Pro/Engineer`s geometric engine, and developed prototype software capable of detecting many of these problems and guiding users towards simplified, useable models. The prototype software was tested using Sandia production solid models, and provided significant leverage in attacking the simplification problem.

  8. Organic Molecular Solids

    CERN Document Server

    Schwoerer, Marcus

    2007-01-01

    This is the first comprehensive textbook on the physical aspects of organic solids. All phenomena which are necessary in order to understand modern technical applications are being dealt with in a way which makes the concepts of the topics accessible for students. The chapters - from the basics, production and characterization of organic solids and layers to organic semiconductors, superconductors and opto-electronical applications - have been arranged in a logical and well thought-out order.

  9. Solid State Research

    Science.gov (United States)

    1993-01-31

    intermediate-field Meissner region, and high-field Bean model . The solid line is a fit of RsM = a + b(f,T)Hrf 2 to the results in the Meissner region...model the results: low-field weak links, intermediate-field Meissner region, and high-field Bean model The solid line is a fit of R1 M-- a + b (f T) Hff

  10. Current immunotherapy for solid tumors.

    Science.gov (United States)

    Barkholt, Lisbeth; Bregni, Marco

    2009-05-01

    Explorative knowledge of cellular and molecular mechanisms of immune function and regulation has provided optimism in developing cancer immunotherapy. However, three decades of experimental and clinical investigations to offer powerful immunotherapeutic strategies against solid tumors, with the possible exception of monoclonal antibody-targeted therapies, have not succeeded in significantly prolonging patient survival. Nonspecific immune approaches, including cytokine-based therapies and allogeneic hematopoietic stem cell transplantation, have so far produced consistent, although limited, results. In this review, we present the developments of cell transfer-based strategies that, in preclinical studies, have demonstrated potential efficacy, but have only established tumor regression in limited numbers of patients. The key to success demands creative combinations of tumor antigens, adjuvance, gene modification and various administration strategies in the development of cell-based therapies together with other cancer-treatment principles, often in a stepwise 'space-rocket-type' approach. Combined efforts of several scientific disciplines, such as tumor biology and immunology, as well as cell and gene research in transplantation, will open new venues. New regulation for clinical trials with advanced therapy medicine products to ensure patient safety will be highlighted.

  11. Phase behaviour of deionized binary mixtures of charged colloidal spheres.

    Science.gov (United States)

    Lorenz, Nina J; Schöpe, Hans Joachim; Reiber, Holger; Palberg, Thomas; Wette, Patrick; Klassen, Ina; Holland-Moritz, Dirk; Herlach, Dieter; Okubo, Tsuneo

    2009-11-18

    We review recent work on the phase behaviour of binary charged sphere mixtures as a function of particle concentration and composition. Both size ratios Γ and charge ratios Λ are varied over a wide range. Unlike the case for hard spheres, the long-ranged Coulomb interaction stabilizes the crystal phase at low particle concentrations and shifts the occurrence of amorphous solids to particle concentrations considerably larger than the freezing concentration. Depending on Γ and Λ, we observe upper azeotrope, spindle, lower azeotrope and eutectic types of phase diagrams, all known well from metal systems. Most solids are of body centred cubic structure. Occasionally stoichiometric compounds are formed at large particle concentrations. For very low Γ, entropic effects dominate and induce a fluid-fluid phase separation. Since for charged spheres the charge ratio Λ is also decisive for the type of phase diagram, future experiments with charge variable silica spheres are suggested.

  12. Immunologic Monitoring of Cellular Responses by Dendritic/Tumor Cell Fusion Vaccines

    Directory of Open Access Journals (Sweden)

    Shigeo Koido

    2011-01-01

    Full Text Available Although dendritic cell (DC- based cancer vaccines induce effective antitumor activities in murine models, only limited therapeutic results have been obtained in clinical trials. As cancer vaccines induce antitumor activities by eliciting or modifying immune responses in patients with cancer, the Response Evaluation Criteria in Solid Tumors (RECIST and WHO criteria, designed to detect early effects of cytotoxic chemotherapy in solid tumors, may not provide a complete assessment of cancer vaccines. The problem may, in part, be resolved by carrying out immunologic cellular monitoring, which is one prerequisite for rational development of cancer vaccines. In this review, we will discuss immunologic monitoring of cellular responses for the evaluation of cancer vaccines including fusions of DC and whole tumor cell.

  13. Lyophilization -Solid Waste Treatment

    Science.gov (United States)

    Litwiller, Eric; Flynn, Michael; Fisher, John; Reinhard, Martin

    2004-01-01

    This paper discusses the development of a solid waste treatment system that has been designed for a Mars transit exploration mission. The technology described is an energy-efficient lyophilization technique that is designed to recover water from spacecraft solid wastes. Candidate wastes include feces, concentrated brines from water processors, and other solid wastes that contain free water. The system is designed to operate as a stand-alone process or to be integrated into the International Space Station Waste Collection System. In the lyophilization process, water in an aqueous waste is frozen and then sublimed, separating the waste into a dried solid material and liquid water. The sublimed water is then condensed in a solid ice phase and then melted to generate a liquid product. In the subject system the waste solids are contained within a 0.2 micron bio-guard bag and after drying are removed from the system and stored in a secondary container. This technology is ideally suited to applications such as the Mars Reference Mission, where water recovery rates approaching 100% are desirable but production of CO2 is not. The system is designed to minimize power consumption through the use of thermoelectric heat pumps. The results of preliminary testing of a prototype system and testing of the final configuration are provided. A mathematical model of the system is also described.

  14. Solid Mathematical Marbling.

    Science.gov (United States)

    Lu, Shufang; Jin, Xiaogang; Jaffer, Aubrey; Gao, Fei; Mao, Xiaoyang

    2016-05-25

    Years of research have been devoted to computer-generated two-dimensional marbling. However, three-dimensional marbling has yet to be explored. In this paper, we present mathematical marbling of three-dimensional solids which supports a compact random-access vector representation. Our solid marbling textures are created by composing closed-form 3D pattern tool functions. These tool functions are an injection function and five deformation functions. The injection function is used to generate basic patterns, and the deformation functions are responsible for transforming the basic pattern into complex marbling effects. The resulting representation is feature preserving and resolution-independent. Our approach can render high-quality images preserving both the sharp features and the smooth color variations of a solid texture. When implemented on the GPU, our representation enables efficient color evaluation during the real-time solid marbling texture mapping. The color of a point in the volume space is computed by the 3D pattern tool functions from its coordinates. Our method consumes very little memory because only the mathematical functions and their corresponding parameters are stored. In addition, we develop an intuitive user interface and a genetic algorithm to facilitate the solid marbling texture authoring process. We demonstrate the effectiveness of our approach through various solid marbling textures and 3D objects carved from them.

  15. The structural behaviour of laminated-guadua panels under parallel plane loads

    Directory of Open Access Journals (Sweden)

    Juan Jacobo Pinilla Rodríguez

    2012-03-01

    Full Text Available The Universidad Nacional de Colombia "Analysis, Design and Materials - GIES" research group tested two types of panels made from Guadua angustifolia Kunth and poly vinyl acetate (PVA as a first step in studying the behaviour of laminated guadua frames having panels of the same material under seismic load: type 1 panels had a solid cross-section and type 2 panels a sandwich cross-section.Each type of panel had three different heights and 10 replicates were tested for each type and height (60 trials in total.Each panel’s load compared to displacement curve was found; 0.34m and 0.63m type1 panels had initial elastic behaviour followed by inelastic behaviour while 0.98 m panels made of both types had an almost completely elastic behaviour until failure. All panels became crushed at their base; however, the main failure mechanism was warping.

  16. Consumer behaviour and the environment

    DEFF Research Database (Denmark)

    Thøgersen, John

    2005-01-01

    -style are not easily achieved, however. In a report issued by United Na-tions Secretary-General Kofi Annan in preparation for the Johannesburg Summit it was concluded that "Progress towards the goals established at Rio has been slower than anticipated and in some respects conditions are worse than they were ten years...... for the environmental cause, but for facilitating environmentally responsible behaviour in many specific ways. Research dealing with the diverse roles of information in the environmental field shows a need to distinguish between different forms and objectives of information, but also, it needs to be stressed......, that information alone is usually not sufficient to change behaviour (Stern, 1999). My aim here is to present a broad-brush overview of some of the most important roles that information has been found to play as a tool for pro-moting environmentally responsible consumer behaviour. Because this publication...

  17. Norms for environmentally responsible behaviour

    DEFF Research Database (Denmark)

    Thøgersen, John

    The currently used concept of personal or moral norms is ambiguous with regard to its motivational content. Therefore, a revision of the norm taxonomy is suggested, implying a distinction between three types of personal norms, called introjected, identified, and integrated norms. A preliminary...... assessment of the taxonomy is carried out based of a survey of a random sample of Danish residents 18 years or older. A range of norm constructs were measured with regard to four environmentally relevant behaviours: buying organic milk, buying energy saving light bulbs, source-separating compostable kitchen...... is also supported, with the reservation that the different behavioural references are more than just different methods of measuring the same latent construct(s). People evidently hold different norms for different environmentally responsible behaviours....

  18. Static Behaviour of Bucket Foundations

    DEFF Research Database (Denmark)

    Larsen, Kim André

    . The monopod concept is investigated in this thesis, regarding the static behaviour from loads relevant to offshore wind turbines. The main issue in this concept is the rotational stiffness of the foundation and the combined capacity dominated by moments. The vertical bearing capacity of bucket foundations...... theory is proposed. The proposed expression applies to plane strain as well as axis-symmetric stress conditions for foundations with smooth or rough bases. A thorough experimental investigation of the static behaviour of bucket foundations subjected to combined loading is carried out. Laboratory tests...... method is concluded to be a superior method in estimating the post peak behaviour as well as the combined capacity of bucket foundations in relation to the offshore wind turbine problem....

  19. Retailer buying behaviour: A review

    DEFF Research Database (Denmark)

    Hansen, Tommy Holm; Skytte, Hans

    1998-01-01

    With centralised buying organisations, growth in market coverage and turn over retailers have become gatekeepers to the consumer markets. Therefore, knowledge about retailers' and trade buyers' buying behaviour has become important to producers. W review the literature on retailer buying behaviour...... and find that research findings appear scattered and unrelated. Most of the previous research has been concerning with generating lists of criteria used by retailers when deciding whether or not t accept a new product. Other areas that have caught the interest of researcher are: the role of buying...... committees, the relationship with manufacturers, European buying alliances, the use of information, retail buyer task, sales man influences, acce of trade deals, country or origin effects and new information technology. Keywords Retailer buying behaviour, review, buying criteria, retailing, assortment...

  20. Experimental investigations and numerical simulations of notch effect in cellular plastic materials

    Science.gov (United States)

    Marsavina, L.; Linul, E.; Voiconi, T.; Negru, R.

    2016-04-01

    Cellular plastics are light weight structures with many applications in civil, aeronautical, automotive and mechanical engineering. Properties of cellular materials depend on the properties of the solid material, on the shape and dimensions of the cellular structure and on the relative density of the cellular material. Most of cellular plastic materials are crushing in compression and have a brittle behavior in tension. The effect of notches represents an important issue in such materials, taking into account that for packing applications for example, notches/holes should be introduced in the cellular material. This paper investigates the effect of notches in compression for three different densities 100, 145 and 300 kg/m3 polyurethane (PUR) foams. Experimental investigations were performed on rectangular blocks of 100×100×25 mm with 16, 28 and 40 mm central holes. The mechanism of damage was monitored with an IR camera FLIR A40M. Purpose of the numerical simulations was to calibrate a material model, based on compression test for un-notched specimens using the CRUSHABLE FOAM models implemented in ABAQUS SIMULIA. Then the material models were used to simulate the experimental tests on notched blocks. Good agreement was obtained for the load - displacement curves obtained experimentally and from simulation. Also the plastic deformation patterns observed experimentally by IR thermograpghy were obtained numerically using the CRUSHABLE FOAM material model.

  1. On the mechanism by which oil uptake decreases crispy/crunchy behaviour of fried products

    NARCIS (Netherlands)

    Vliet, van T.; Visser, J.E.; Luyten, J.M.J.G.

    2007-01-01

    A large problem for fried snack products with a crispy crust and a soft moist interior is that the crust often loses its crispy character fast, in the order of 3¿20 min. As known during cooling of these snacks adherent oil will be sucked into the crust. The presence of oil in a cellular solid crispy

  2. Customer behaviour and student satisfaction

    Directory of Open Access Journals (Sweden)

    Enache, I. C.

    2011-01-01

    Full Text Available Having to overcome new challenges, the higher education institutions need to understand their customer behaviour. The students’ satisfaction is becoming an important objective for universities and society as the role of the tertiary level institution is being questioned. The aim of this paper is to provide a concrete marketing approach to the student satisfaction problem. The literature review section aims to present resources that deliver relevant and updated information about the marketing perspectives on student satisfaction. A short survey is developed in order to provide insights on student behaviour and student satisfaction.

  3. Markers of cellular senescence. Telomere shortening as a marker of cellular senescence.

    Science.gov (United States)

    Bernadotte, Alexandra; Mikhelson, Victor M; Spivak, Irina M

    2016-01-01

    The cellular senescence definition comes to the fact of cells irreversible proliferation disability. Besides the cell cycle arrest, senescent cells go through some morphological, biochemical, and functional changes which are the signs of cellular senescence. The senescent cells (including replicative senescence and stress-induced premature senescence) of all the tissues look alike. They are metabolically active and possess the set of characteristics in vitro and in vivo, which are known as biomarkers of aging and cellular senescence. Among biomarkers of cellular senescence telomere shortening is a rather elegant frequently used biomarker. Validity of telomere shortening as a marker for cellular senescence is based on theoretical and experimental data.

  4. Hygienic food handling behaviours. An application of the Theory of Planned Behaviour.

    Science.gov (United States)

    Mullan, Barbara A; Wong, Cara L

    2009-06-01

    It is estimated that 5.4 million Australians get sick annually from eating contaminated food and that up to 20% of this illness results from food handling behaviour. A study was undertaken to investigate the efficacy of the Theory of Planned Behaviour (TPB) including past behaviour in predicting safe food handling intention and behaviour. One hundred and nine participants completed questionnaires regarding their attitudes, perceived behavioural control (PBC), subjective norm, intentions and past behaviour. Behaviour was measured 4 weeks later. The TPB predicted a high proportion of variance in both intentions and behaviour, and past behaviour/habit was found to be the strongest predictor of behaviour. The results of the present study suggest interventions aimed at increasing safe food handling intentions should focus on the impact of normative influences and perceptions of control over their food handling environment; whereas interventions to change actual behaviour should attempt to increase hygienic food handling as a habitual behaviour.

  5. Theories of behaviour and behaviour change across the social and behavioural sciences: a scoping review.

    Science.gov (United States)

    Davis, Rachel; Campbell, Rona; Hildon, Zoe; Hobbs, Lorna; Michie, Susan

    2015-01-01

    Interventions to change health-related behaviours typically have modest effects and may be more effective if grounded in appropriate theory. Most theories applied to public health interventions tend to emphasise individual capabilities and motivation, with limited reference to context and social factors. Intervention effectiveness may be increased by drawing on a wider range of theories incorporating social, cultural and economic factors that influence behaviour. The primary aim of this paper is to identify theories of behaviour and behaviour change of potential relevance to public health interventions across four scientific disciplines: psychology, sociology, anthropology and economics. We report in detail the methodology of our scoping review used to identify these theories including which involved a systematic search of electronic databases, consultation with a multidisciplinary advisory group, web searching, searching of reference lists and hand searching of key behavioural science journals. Of secondary interest we developed a list of agreed criteria for judging the quality of the theories. We identified 82 theories and 9 criteria for assessing theory quality. The potential relevance of this wide-ranging number of theories to public health interventions and the ease and usefulness of evaluating the theories in terms of the quality criteria are however yet to be determined.

  6. Glass-like dynamics in the cell and in cellular collectives

    OpenAIRE

    Sadati, Monirosadat; Nourhani, Amir; Fredberg, Jeffrey J.; Qazvini, Nader Taheri

    2014-01-01

    Prominent fluctuations, heterogeneity, and cooperativity dominate the dynamics of the cytoskeleton as well as the dynamics of the cellular collective. Such systems are out of equilibrium, disordered, and remain poorly understood. To explain these findings, here we consider a unifying mechanistic rubric that imagines these systems as comprising phases of soft condensed matter in proximity to a glass or jamming transition, with associated transitions between solid-like versus liquid-like phases...

  7. Materials Research Society, Symposium Proceedings, Volume 521. Porous and Cellular Materials for Structural Applications

    Science.gov (United States)

    2007-11-02

    blowing agent at 680°C. After stirring, the molten material is cured to expand and fill up the mold for about 15 minutes. Then, the foamed molten...closed cell cellular solids. A "perfect" model is first discussed and shown to predict the behavior of PVC foams well. However, this model over...variations (Section VI), and non-uniform cell shapes (Section VII). Fig. 1. Micro graphs of Divinycell [7] HI30 expanded PVC (left) and Alporas [8

  8. CELLULAR INTERACTIONS MEDIATED BY GLYCONECTIDS

    Directory of Open Access Journals (Sweden)

    O.Popescu

    1999-01-01

    Full Text Available Cellular interactions involve many types of cell surface molecules and operate via homophilic and/or heterophilic protein-protein and protein-carbohydrate binding. Our investigations in different model-systems (marine invertebrates and mammals have provided direct evidence that a novel class of primordial proteoglycans, named by us gliconectins, can mediate cell adhesion via a new alternative molecular mechanism of polyvalent carbohydrate-carbohydrate binding. Biochemical characterization of isolated and purified glyconectins revealed the presence of specific carbohydrate structures, acidic glycans, different from classical glycosaminoglycans. Such acidic glycans of high molecular weight containing fucose, glucuronic or galacturonic acids, and sulfate groups, originally found in sponges and sea urchin embryos, may represent a new class of carbohydrate carcino-embryonal antigens in mice and humans. Such interactions between biological macromolecules are usually investigated by kinetic binding studies, calorimetric methods, X-ray diffraction, nuclear magnetic resonance, and other spectroscopic analyses. However, these methods do not supply a direct estimation of the intermolecular binding forces that are fundamental for the function of the ligand-receptor association. Recently, we have introduced atomic force microscopy to quantify the binding strength between cell adhesion proteoglycans. Measurement of binding forces intrinsic to cell adhesion proteoglycans is necessary to assess their contribution to the maintenance of the anatomical integrity of multicellular organisms. As a model, we selected the glyconectin 1, a cell adhesion proteoglycan isolated from the marine sponge Microciona prolifera. This glyconectin mediates in vivo cell recognition and aggregation via homophilic, species-specific, polyvalent, and calcium ion-dependent carbohydrate-carbohydrate interactions. Under physiological conditions, an adhesive force of up to 400 piconewtons

  9. Topological Design of Cellular Phononic Band Gap Crystals

    Directory of Open Access Journals (Sweden)

    Yang Fan Li

    2016-03-01

    Full Text Available This paper systematically investigated the topological design of cellular phononic crystals with a maximized gap size between two adjacent bands. Considering that the obtained structures may sustain a certain amount of static loadings, it is desirable to ensure the optimized designs to have a relatively high stiffness. To tackle this issue, we conducted a multiple objective optimization to maximize band gap size and bulk or shear modulus simultaneously with a prescribed volume fraction of solid material so that the resulting structures can be lightweight, as well. In particular, we first conducted the finite element analysis of the phononic band gap crystals and then adapted a very efficient optimization procedure to resolve this problem based on bi-directional evolutionary structure optimization (BESO algorithm in conjunction with the homogenization method. A number of optimization results for maximizing band gaps with bulk and shear modulus constraints are presented for out-of-plane and in-plane modes. Numerical results showed that the optimized structures are similar to those obtained for composite case, except that additional slim connections are added in the cellular case to support the propagation of shear wave modes and meanwhile to satisfy the prescribed bulk or shear modulus constraints.

  10. Characterization of cell suspensions from solid tumors

    Energy Technology Data Exchange (ETDEWEB)

    Pallavicini, M.

    1985-07-10

    The desirable features of cells in suspension will necessarily be dependent upon the use for which the cells were prepared. Adequate cell yield or recovery is defined by the measurement to be performed. Retention of cellular morphology is important for microscopic identification of cell types in a heterogenous cell suspension, and may be used to determine whether the cells in suspension are representative of those in the tumor in situ. Different dispersal protocols may yield cells with different degrees of clonogenicity, as well as altered biochemical features, such as loss of cellular proteins, surface antigens, nucleotide pools, etc. The quality of the cell suspension can be judged by the degree of cell clumping and level of cellular debris, both of which impact on flow cytometric measurements and studies in which the number of cells be known accurately. Finally, if the data measured on the cells in suspension are to be extrapolated to phenomena occurring in the tumor in situ, it is desirable that the cells in suspension are representative of those in the solid tumor in vivo. This report compares characteristics of tumor cell suspensions obtained by different types of selected disaggregation methods. 33 refs., 2 figs., 4 tabs.

  11. Label-free imaging to study phenotypic behavioural traits of cells in complex co-cultures

    Science.gov (United States)

    Suman, Rakesh; Smith, Gabrielle; Hazel, Kathryn E. A.; Kasprowicz, Richard; Coles, Mark; O'Toole, Peter; Chawla, Sangeeta

    2016-02-01

    Time-lapse imaging is a fundamental tool for studying cellular behaviours, however studies of primary cells in complex co-culture environments often requires fluorescent labelling and significant light exposure that can perturb their natural function over time. Here, we describe ptychographic phase imaging that permits prolonged label-free time-lapse imaging of microglia in the presence of neurons and astrocytes, which better resembles in vivo microenvironments. We demonstrate the use of ptychography as an assay to study the phenotypic behaviour of microglial cells in primary neuronal co-cultures through the addition of cyclosporine A, a potent immune-modulator.

  12. Behaviour of emerging contaminants in sewage sludge after anaerobic digestion.

    Science.gov (United States)

    Boix, C; Ibáñez, M; Fabregat-Safont, D; Morales, E; Pastor, L; Sancho, J V; Sánchez-Ramírez, J E; Hernández, F

    2016-11-01

    Nowadays, there is an increasing concern over the presence of contaminants in the aquatic environment, where they can be introduced from wastewater after their incomplete removal in the treatment plants. In this work, degradation of selected emerging pollutants in the aqueous and solid phases of sewage sludge has been investigated after anaerobic digestion using two different digesters: mesophilic and thermophilic. Initially, sludge samples were screened by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS) for identification of emerging contaminants in the samples. In a second step, a target quantitative method based on LC coupled to tandem MS was applied for selected pollutants identified in the previous screening. The behaviour of the compounds under anaerobic conditions was studied estimating the degradation efficiency and distribution of compounds between both sludge phases. Irbesartan and benzoylecgonine seemed to be notably degraded in both phases of the sludge. Venlafaxine showed a significant concentration decrease in the aqueous phase in parallel to an increase in the solid phase. The majority of the compounds showed an increase of their concentrations in both phases after the digestion. Concentrations in the solid phase were commonly higher than in the aqueous for most contaminants, indicating that they were preferentially adsorbed onto the solid particles.

  13. Cellular traction stresses increase with increasing metastatic potential.

    Directory of Open Access Journals (Sweden)

    Casey M Kraning-Rush

    Full Text Available Cancer cells exist in a mechanically and chemically heterogeneous microenvironment which undergoes dynamic changes throughout neoplastic progression. During metastasis, cells from a primary tumor acquire characteristics that enable them to escape from the primary tumor and migrate through the heterogeneous stromal environment to establish secondary tumors. Despite being linked to poor prognosis, there are no direct clinical tests available to diagnose the likelihood of metastasis. Moreover, the physical mechanisms employed by metastatic cancer cells to migrate are poorly understood. Because metastasis of most solid tumors requires cells to exert force to reorganize and navigate through dense stroma, we investigated differences in cellular force generation between metastatic and non-metastatic cells. Using traction force microscopy, we found that in human metastatic breast, prostate and lung cancer cell lines, traction stresses were significantly increased compared to non-metastatic counterparts. This trend was recapitulated in the isogenic MCF10AT series of breast cancer cells. Our data also indicate that increased matrix stiffness and collagen density promote increased traction forces, and that metastatic cells generate higher forces than non-metastatic cells across all matrix properties studied. Additionally, we found that cell spreading for these cell lines has a direct relationship with collagen density, but a biphasic relationship with substrate stiffness, indicating that cell area alone does not dictate the magnitude of traction stress generation. Together, these data suggest that cellular contractile force may play an important role in metastasis, and that the physical properties of the stromal environment may regulate cellular force generation. These findings are critical for understanding the physical mechanisms of metastasis and the role of the extracellular microenvironment in metastatic progression.

  14. The cellular response of Saccharomyces cerevisiae to multi-walled carbon nanotubes (MWCNTs

    Directory of Open Access Journals (Sweden)

    Chantelle L. Phillips

    2015-03-01

    Full Text Available Nanoparticles (NPs especially those of carbon nanotubes (CNTs have remarkable properties that are very desirable in various biological and biomedical applications. This has necessitated the rapid study of CNT toxicities, to augment their safe use, particularly, in yeast cells. The yeast cell; Saccharomyces cerevisiae is a widely used industrial and biological organism with very limited data regarding their cellular behaviour in NPs. The current study examines the cellular response of S. cerevisiae to MWCNTs. The CNTs were produced by the swirled floating catalytic chemical vapour deposition (SFCCVD method and covalently functionalised using 1,3-dipolar cycloaddition. The CNT properties such as size, surface area, quality and surface vibrations were characterized using TEM, SEM, BET, TGA and Raman spectroscopy, respectively. The cellular uptake was confirmed with a FITC functionalised MWCNTs using 1H NMR, SEM and TEM. The CNT concentrations of 2–40 μg/ml were used to determine the cellular response through cell growth phases and cell viability characteristics. The TEM and SEM analyses showed the production of MWCNTs with an average diameter of 53 ± 12 nm and a length of 2.5 ± 0.5 μm. The cellular uptake of FITC-MWCNTs showed 100% internalisation in the yeast cells. The growth curve responses to the MWCNT doses showed no significant differences at P > 0.05 on the growth rate and viability of the S. cerevisiae cells.

  15. Cellular Factors Required for Lassa Virus Budding

    OpenAIRE

    Urata, Shuzo; Noda, Takeshi; Kawaoka, Yoshihiro; Yokosawa, Hideyoshi; Yasuda, Jiro

    2006-01-01

    It is known that Lassa virus Z protein is sufficient for the release of virus-like particles (VLPs) and that it has two L domains, PTAP and PPPY, in its C terminus. However, little is known about the cellular factor for Lassa virus budding. We examined which cellular factors are used in Lassa virus Z budding. We demonstrated that Lassa Z protein efficiently produces VLPs and uses cellular factors, Vps4A, Vps4B, and Tsg101, in budding, suggesting that Lassa virus budding uses the multivesicula...

  16. Cryptographic primitives based on cellular transformations

    Directory of Open Access Journals (Sweden)

    B.V. Izotov

    2003-11-01

    Full Text Available Design of cryptographic primitives based on the concept of cellular automata (CA is likely to be a promising trend in cryptography. In this paper, the improved method performing data transformations by using invertible cyclic CAs (CCA is considered. Besides, the cellular operations (CO as a novel CAs application in the block ciphers are introduced. Proposed CCAs and COs, integrated under the name of cellular transformations (CT, suit well to be used in cryptographic algorithms oriented to fast software and cheap hardware implementation.

  17. Cellular Cell Bifurcation of Cylindrical Detonations

    Institute of Scientific and Technical Information of China (English)

    HAN Gui-Lai; JIANG Zong-Lin; WANG Chun; ZHANG Fan

    2008-01-01

    Cellular cell pattern evolution of cylindrically-diverging detonations is numerically simulated successfully by solving two-dimensional Euler equations implemented with an improved two-step chemical kinetic model. From the simulation, three cell bifurcation modes are observed during the evolution and referred to as concave front focusing, kinked and wrinkled wave front instability, and self-merging of cellular cells. Numerical research demonstrates that the wave front expansion resulted from detonation front diverging plays a major role in the cellular cell bifurcation, which can disturb the nonlinearly self-sustained mechanism of detonations and finally lead to cell bifurcations.

  18. Optimal Band Allocation for Cognitive Cellular Networks

    CERN Document Server

    Liu, Tingting

    2011-01-01

    FCC new regulation for cognitive use of the TV white space spectrum provides a new means for improving traditional cellular network performance. But it also introduces a number of technical challenges. This letter studies one of the challenges, that is, given the significant differences in the propagation property and the transmit power limitations between the cellular band and the TV white space, how to jointly utilize both bands such that the benefit from the TV white space for improving cellular network performance is maximized. Both analytical and simulation results are provided.

  19. On-Chip Detection of Cellular Activity

    Science.gov (United States)

    Almog, R.; Daniel, R.; Vernick, S.; Ron, A.; Ben-Yoav, H.; Shacham-Diamand, Y.

    The use of on-chip cellular activity monitoring for biological/chemical sensing is promising for environmental, medical and pharmaceutical applications. The miniaturization revolution in microelectronics is harnessed to provide on-chip detection of cellular activity, opening new horizons for miniature, fast, low cost and portable screening and monitoring devices. In this chapter we survey different on-chip cellular activity detection technologies based on electrochemical, bio-impedance and optical detection. Both prokaryotic and eukaryotic cell-on-chip technologies are mentioned and reviewed.

  20. Imaging in cellular and tissue engineering

    CERN Document Server

    Yu, Hanry

    2013-01-01

    Details on specific imaging modalities for different cellular and tissue engineering applications are scattered throughout articles and chapters in the literature. Gathering this information into a single reference, Imaging in Cellular and Tissue Engineering presents both the fundamentals and state of the art in imaging methods, approaches, and applications in regenerative medicine. The book underscores the broadening scope of imaging applications in cellular and tissue engineering. It covers a wide range of optical and biological applications, including the repair or replacement of whole tiss